Patent Publication Number: US-2013231060-A1

Title: Systems, methods and apparatus for determining a radiated performance of a wireless device

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §120 
     The present application for patent is a continuation of patent application Ser. No. 12/829,137, entitled, “SYSTEMS, METHODS AND APPARATUS FOR DETERMINING A RADIATED PERFORMANCE OF A WIRELESS DEVICE”, filed Jul. 1, 2010, currently pending, which claims priority to a continuation of patent application Ser. No. 11/258,334, entitled, “SYSTEMS, METHODS AND APPARATUS FOR DETERMINING A RADIATED PERFORMANCE OF A WIRELESS DEVICE”, filed Oct. 24, 2005, currently pending, which claims priority to Provisional Application No. 60/660,918 entitled “METHOD AND APPARATUS FOR PERFORMING RADIATED ANTENNA TESTS” filed Mar. 11, 2005, and Provisional Application No. 60/621,883 entitled “ANTENNA CORRELATION FROM MEASURED COMPLEX RADIATION PATTERNS” filed Oct. 25, 2004, all assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     The described embodiments relate to wireless communications devices, and more particularly, to systems, methods, apparatus, processors and computer readable media for determining the radiated performance of an antenna system associated with a wireless device. 
     Wireless devices utilize radio waves to provide long distance communications without the physical constraints of a wire-based system. The wireless device transmits and receives information using via the radio waves, which may be carried over predetermined frequency bands. An antenna connected to a transmitter and a receiver, along with the associated circuitry, allows the wireless device to transmit and receive these radio wave signals. The design of the wireless device, including the antenna and the various transmit- and receiver-related components, impact the ability of the wireless device to transmit and receive radio wave signals, and hence define and affect the radiated performance of the device. Thus, it is desirable to determine and tune the radiated performance of a wireless device to optimize the ability of the wireless device to communicate radio wave signals. 
     Prior art methods of determining the radiated performance of a wireless device, however, have a number of drawbacks. Some tests to determine radiated performance involve destructive modification of the wireless device. For instance, in one example, the signal path between the antenna and receiver is interrupted and re-routed to an external radio frequency (“RF”) connector. Radiated signal power measurements are then made by external test equipment interfaced at this connector, thereby acting as a substitute for the receiver on the wireless device. The presence of the external RF connector and the associated external cable can distort the true radiated performance of the wireless device. Further, these destructive modifications add expense to the testing procedure due to both the additional equipment and the additional manpower required to make the modification. Additionally, destructive modifications add further expense by making the modified wireless device un-usable for other tests. 
     Additionally, in a wireless communication system, an RF modulated signal from a transmitter may reach a receiver via a number of propagation paths. The characteristics of the propagation paths typically vary over time due to a number of factors such as fading and multipath. 
     Further, structures such as buildings, and surrounding terrain, including walls and hillsides, contribute to the scattering and reflection of the transmitted signal. The scattering and reflection of the transmit signal results in multiple signal paths from the transmitter to the receiver. The contributors to the multiple signal paths change as the receiver moves. 
     Other signal sources also result in degradation of the desired signal. The other signal sources may be other transmitters intentionally operating on the same frequency as the desired signal, as well as transmitters that generate spurious signals in the frequency band of the desired signal. Yet another source of signal degradation may be generated within the receiver itself. Signal amplifiers and signal processing stages within the receiver may degrade the level of the desired signal with respect to the level of thermal noise. The signal amplifiers and processors within the receiver may also generate noise products or distort the received signal and further degrade its quality. 
     To provide diversity against deleterious path effects and improve performance, multiple transmit and receive antennas may be used. If the propagation paths between the transmit and receive antennas are linearly independent (i.e., a transmission on one path is not formed as a linear combination of the transmissions on other paths), which is generally true to at least an extent, then the likelihood of correctly receiving a data transmission increases as the number of antennas increases. Thus, generally, diversity increases and performance improves as the number of transmit and receive antennas increases. 
     Further, a wireless device may use multiple antennas for a number of reasons. For example, a wireless device often needs to operate over multiple bands and service multiple operating modes. Another reason is that advanced transceiver architectures are being implemented that use multiple antennas for improving the performance of some of these modes in the field. When operated simultaneously, these modes can interfere with each other, causing degrading overall performance. So it is important to devise accurate means of evaluating the radiated performance of a wireless device that can capture the effects of self-interference. Current methods require several steps to evaluate a combined device/antenna design, and there is ambiguity with respect to test accuracy with current “cabled” tests. Therefore, dependable design and test methodologies have yet to be developed. 
     Thus, new and improved systems, apparatus, computer-readable media, processors and methods for determining the radiated performance of a wireless device are desired. 
     SUMMARY 
     The described embodiments allow for the determination, in a single test and using a single, unaltered wireless device, one or more radiated performance characteristics, such as Effective Isotropic Radiated Power (“EIRP”), receiver sensitivity, Total Radiated Power (“TRP”), Total Isotropic Sensitivity (“TIS”), and envelope correlation, which is related to Rx diversity performance). 
     In one embodiment, for example, a method of determining a radiated performance characteristic of a wireless device comprises determining a measured signal characteristic of a signal received the wireless device at each one of a plurality of positions associated with a predetermined radiated performance test. The method further includes recording the measured signal characteristics in a test log on the wireless device. And, the method includes recording, in the test log on the wireless device, synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the measured signal characteristics. The measured signal characteristics and the synchronization data are determinative of the radiated performance characteristic of the wireless device. 
     In another embodiment, a computer program is resident in a computer readable medium that, when executed, directs a computer device to perform the actions of determining a measured signal characteristic of a signal received by a receiver module of a wireless device at each one of a plurality of positions associated with a predetermined radiated performance test. The actions further include recording the measured signal characteristics in a test log on the wireless device. And, the action include recording, in the test log on the wireless device, synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the measured signal characteristics. The measured signal characteristics and the synchronization data are determinative of a radiated performance characteristic of the wireless device. In a related embodiment, at least one processor is configured to performed the above-described actions. 
     In yet another embodiment, a wireless device comprises a means for determining a measured signal characteristic for a signal received at each one of a plurality of positions associated with a predetermined radiated performance test. The device further comprises a means for recording the measured signal characteristics. Additionally, the device comprises a means for recording synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the measured signal characteristics. The measured signal characteristics and the synchronization data are determinative of a radiated performance characteristic of the wireless device. 
     In still another embodiment, a wireless device comprises a receiver module operable to receive a signal at each one of a plurality of positions associated with a predetermined radiated performance test. The signal has a measured signal characteristic as determined by the receiver module, and the signal further has synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the measured signal characteristics. And, the device comprises a data repository having a device test log comprising the measured signal characteristic and the synchronization data corresponding to each one of the plurality of positions. The measured signal characteristics and the synchronization data are determinative of a radiated performance characteristic of the wireless device. 
     In a further embodiment, a method of determining a radiated characteristic of a wireless device comprises transmitting a signal having a reference signal characteristic to the wireless device at each one of a plurality of positions associated with a predetermined radiated performance test. The method further includes transmitting synchronization data to the wireless device, where the synchronization data corresponds to a respective position for each one of the plurality of positions and further corresponds to each of the transmitted signal characteristics. Additionally, the reference signal characteristics and the synchronization data are used to determine a radiated performance characteristic of the wireless device. In a related embodiment, at least one processor is configured to performed the above-described actions. In another related embodiment, a computer program resident in a computer readable medium that, when executed, directs a computer device to perform the actions noted above. 
     In another embodiment, an apparatus for determining a radiated performance of a wireless device comprises a means for transmitting a signal having a reference signal characteristic to the wireless device at each one of a plurality of positions associated with a predetermined radiated performance test. The apparatus further comprises a means for transmitting synchronization data to the wireless device, the synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the transmitted signal characteristics. The reference signal characteristics and the synchronization data are used to determine a radiated performance characteristic of the wireless device. 
     In still another embodiment, a controller for determining a radiated performance of a wireless device comprises a radio signal system operable to transmit a signal to the wireless device at each one of a plurality of positions associated with a predetermined radiated performance test. The signal comprises a reference signal characteristic and synchronization data, the synchronization data corresponding to a respective position for each one of the plurality of positions and further corresponding to each of the reference signal characteristics. The reference signal characteristics and the synchronization data are used to determine a radiated performance characteristic of the wireless device. 
     In a further embodiment, a system for determining a radiated performance of a wireless device comprises controller system operable to generate a control signal based on a predetermined radiated performance test. The control signal comprises a positioning component and a corresponding signaling component, where the positioning component defines a selected one of a plurality of predetermined positions, and where the signaling component defines a radio signal having a reference signal characteristic and predetermined synchronization data. Further, the predetermined synchronization data corresponds to the selected one of the plurality of predetermined positions. Additionally, the system comprises a radio signal system comprising a signal generator, where the radio signal system is operable to receive at least a portion of the control signal and generate the radio signal based on the signaling component. 
     In another embodiment, a wireless device comprises a receiver mechanism operable to receive a signal having a reference signal characteristic and predetermined synchronization data. The reference signal characteristic is associated with a predetermined radiated performance test, and wherein the predetermined synchronization data corresponds to a selected one of a plurality of positions of the wireless device associated with the predetermined radiated performance test. Further, the device comprises a processing system in communication with the receiver mechanism and operable to determine a measured signal characteristic based on the received signal. The measured signal characteristic corresponds to the reference signal characteristic, and the processing system is further operable to parse the predetermined synchronization data from the received signal. Further, the device comprises a data repository operable to store a test log comprising the measured signal characteristic and the corresponding predetermined synchronization data. And, the device comprises a radiated performance test module operable to gather, from the processing system, and cause storage, in the data repository, of the measured signal characteristic and the corresponding predetermined synchronization data, both at least partially determinable of a predetermined radiated performance characteristic of the wireless device based on the predetermined radiated performance test. 
     In another embodiment, a method of determining a radiated performance of a wireless device comprises positioning a wireless device at a selected one of a plurality of predetermined positions associated with a predetermined radiated performance test. The method includes sending a signal to the wireless device, where the signal has a reference signal characteristic and predetermined synchronization data that corresponds to the selected position. Further, the method includes receiving a record from the wireless device, where the record includes a measured signal characteristic as measured by a receiver module on the wireless device and corresponding to the reference signal characteristic, and correlated with the predetermined synchronization data. Additionally, the method includes synchronizing the measured signal characteristic with position information corresponding to the selected position based on the predetermined synchronization data. And, the method includes generating a radiated performance characteristic of the wireless device based on the synchronized measured signal characteristic and position information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of one embodiment of a system for determining a radiated performance of a wireless device; 
         FIG. 2  is a schematic diagram of one embodiment of a wireless device used in the system of  FIG. 1 ; 
         FIG. 3  is a schematic diagram of one embodiment of a user interface/view operable on the wireless device of  FIG. 1 ; 
         FIG. 4  is a schematic diagram of one embodiment of a controller system used in the system of  FIG. 1 ; 
         FIG. 5  schematic diagram of one embodiment of the components of a predetermined radiated performance test used by the wireless device and/or the controller system of  FIG. 1 ; 
         FIG. 6  is a schematic diagram of one embodiment of a control test log associated with the controller system of  FIG. 4 . 
         FIG. 7  is a flowchart of one embodiment of a method operable on a wireless device for determining a radiated performance of the wireless device of  FIG. 1 ; 
         FIG. 8  is a flowchart of one embodiment of a method operable on an apparatus, such a the controller system, for determining a radiated performance of the wireless device of  FIG. 1 ; 
         FIG. 9  is a graph of antenna rho values measured from complex radiated patterns, according to the described embodiments, compared with antenna rho values measured in the field for a number of different types of phones; and 
         FIG. 10  is a table including calculated rho values, according to the described embodiments, for a number of different environments or channel models that represent incoming electromagnetic fields having different behaviors. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , in one embodiment, a system  10  for determining a radiated performance of a wireless device  12  includes a controller system  14  operable to generate a control signal  16  to transmit a radio wave signal  18  to wireless device  12 . Wireless device  12  is located within a test chamber  20  at a position  22  selected from a plurality of predetermined positions associated with a predetermined radiated performance test  24  being run by controller system  14 . Control signal  16  includes a positioning component  26 , which defines the physical coordinates of selected position  22  and thereby dictates the movements of a positioning system  28  to which wireless device  12  is mounted. Further, control signal  16  includes a corresponding signaling component  30 , which defines a radio wave signal  18  and thereby dictates a transmission by radio signal system  32 . In one embodiment, for example, radio signal system  32  simulates a base station in a cellular phone network, and thus radio wave signal  18  may be considered a forward channel signal. Further, radio wave signal  18  may include an actual or reference signal characteristic  34 , such as a signal power, and predetermined synchronization data  36 , such as position information or time information that corresponds to selected position  22 . For example, reference signal characteristic  34  is a known characteristic or value that may be used as a baseline value for later calculations, such as a gain calculation. Similarly, predetermined synchronization data  36  allows measurements made by wireless device  12  to be correlated to the physical coordinates of position  22  of wireless device  12  at the time when the measurement was obtained. 
     Wireless device  12  receives and processes signal  18 , resulting in generating a measured signal characteristic  38  corresponding to reference signal characteristic  34 . In other words, measured signal characteristic  38  is the received value, as measured by receiver-related components resident on wireless device  12 , of reference signal characteristic  34 . Further, wireless device  12  parses synchronization data  36  from signal  18 , thereby providing the ability to relate the respective measured signal characteristic  38  to the respective selected position  22  at which the measurement occurred. Additionally, wireless device  12  includes a radiated performance test module  40  which monitors the measurement of the received signal and directs the parsing of its data. Further, radiated performance test module  40  executes to log measured signal characteristic  38  and synchronization data  36 , thereby forming a record of the test conditions and test results for each selected position  22 . System  10  then sequences through the remaining plurality of predetermined positions until the signals are received at all positions as determined by the given predetermined radiated performance test  24 . 
     Once all testing information has been logged, radiated performance testing module  40  analyzes all of the logged measured signal characteristics  38  and corresponding synchronization data  36  and generates a radiated performance characteristic  42  for wireless device  12 . In one embodiment, for example, radiated performance characteristic  42  may include a radiated sensitivity metric, which is a function of the power gain and/or the voltage gain at an antenna of wireless device  12 , and which may be measured for a single or for multiple antennas. For an embodiment of wireless device  12  having multiple antennas, radiated performance characteristic  38  may include complex voltage receive gains, which are utilized to predict the correlation between the multiple receive chains/antennas, thereby providing an indication of the diversity gain provided by the given antenna set-up. 
     In another embodiment, for example, where synchronization data  36  includes time information, radiated performance characteristic  42  may be determined at controller system  14 . In this case, the log of measured signal characteristics  38  and corresponding synchronization data  36  may be transferred from wireless device  12  to a test manager module  44  located at controller system  14 . Test manager module  44  maintains another log of corresponding time information and position information, which it correlates with the log from wireless device  12  to produce a record or log of position information synchronized with measured signal characteristics  38  for each position dictated by predetermined radiated performance test  24 . In this case, test manager module  44  initiates the analysis of this synchronized log to determine radiated performance characteristic  42 . 
     In other embodiments, for example, predetermined radiated performance test  24  may include a test that involves a wireless device-originated radio wave signal  46  transmitted to radio signal system  32 . This test is a performance test of the transmit chain/antenna of wireless device  12 . In an embodiment where radio signal system  32  simulates a base station of a cellular telephone network, wireless device-originated radio wave signal  46  may be considered a reverse channel signal. Signal  46  includes a reference signal characteristic  48 , which may be used as a baseline for future calculation, and radio signal system  32  receives and processes signal  46 , thereby generating a corresponding measured signal characteristic  50  as received by system  32 . In this embodiment, test management module  44  on controller system  14  executes to log measured signal characteristic  50  and the corresponding position information found in position component  26 . System  10  then sequences through the remaining plurality of predetermined positions until the signals  46  are received at all positions as determined by the given predetermined radiated performance test  24 . Once all testing information has been logged, test management module  44  analyzes all of the logged measured signal characteristics  50  and corresponding position information from position components  26  (which also may be considered synchronization information  36 ) and generates radiated performance characteristic  42  for wireless device  12 . In this case, for example, radiated performance characteristic  42  may include a measure of the transmission performance of wireless device  12 , such as a transmit power gain. Further, wireless device  12  may be set-up to simultaneously receive signal  18  and transmit signal  46 , thereby shortening testing times if there is an overlap in the plurality of predetermined positions associated with each test. 
     Thus, system  10  advantageously includes logging of receiver data directly on wireless device  12 , thereby eliminating the need for external connectors and cables that may distort the true receiver-related radiated performance of the device. Further, system  10  advantageously provides for the wireless synchronization of the measured signal characteristic  38  and the position information or physical coordinates corresponding to each selected position  22 , thereby eliminating the need for external connectors and cables connected to external synchronization and post-processing equipment. Further, the logging and synchronization capability provided by wireless device  12  of system  10  allows for the simultaneous performance of multiple radiated performance tests. Therefore, system  10  provides an efficient set-up for determining the radiated performance of wireless device  12 . 
     In one particular embodiment, for example, the systems, apparatus and methods described herein aide in the radiated testing of mobile phones. In this embodiment, several radiated performance characteristics  42  can be derived from measured data collected in a single test. In particular, the radiated performance characteristics  42  that can be determined are: a total radiated power (“TRP”) characteristic, a total isotropic sensitivity (“TIS”) characteristic, a peak effective isotropic radiated power (“EIRP”) characteristic, a peak receiver sensitivity characteristic, a peak gain characteristic, an average gain characteristic, and a pattern correlation for diversity enabled phones. Generally, the described embodiments perform, over-the-air, complex receive and maximum transmit EIRP pattern measurements at three channel frequencies without requiring test cables being connected to the test phone. By performing the predetermined radiated tests wirelessly, the described embodiments improve measurement accuracy by eliminating external antenna test cables that can distort radiation patterns. Further, the described embodiments do not require special test fixtures as only one phone is needed for all tests; in contrast, the prior art requires a separate cabled phone fixture for antenna gain/pattern tests and a second, wireless phone for the peak EIRP and receive sensitivity radiated tests. Additionally, this particular embodiment provides accelerated testing methodologies, as described in more detail below, that are much faster than current TRP and TIS test methodologies. For example, based on experimental results using the present system, the total duration of the TRP and TIS tests is about 1.75 hours for low, mid, and high frequencies, compared with about a 3-5 hour duration for the prior art TIS test at only one frequency. 
     In this particular embodiment, for example, the measurements are performed in a calibrated far-field anechoic chamber. The testing application is loaded into the test phone while other special purpose control and post processing software is loaded into a host computer controlling the chamber equipment. A cell site simulator or call box is connected to the chamber horn antenna, thereby enabling an over-the-air (OTA) call to a test phone mounted on a rotating pedestal at the far end of the chamber. 
     For receive mode tests, the phone is commanded to log user-defined data packets to memory on the test phone. The defined data packets, such as a “finger channel estimate” log packet, contain the complex pilot signals (e.g., In-phase and Quadrature-phase) received by the phone&#39;s antennae when the phone is illuminated by an electromagnetic plane wave transmitted from the call box equipment. The logging may be triggered by sending commands from the call box over-the-air to the test phone. By synchronizing this logging event with the movement of the pedestal and test phone, the complex in-phase and quadrature-phase receive pattern data is obtained at each measurement angle over a field of view covering a sphere. Further, tests are done with the chamber horn oriented for vertical and horizontal polarizations, and thus vertical and horizontal receive patterns are obtained. Additionally, for diversity-enabled phones, the complex receive pattern of the secondary antenna is obtained by logging the same packet data in a similar manner. 
     For transmit mode tests, a power meter is used to measure the radiated power transmitted by the test phone in a given measurement direction with the phone transmitter at maximum power. The test phone is commanded, such as via OTA signals from the call box equipment, to radiate at its maximum transmit power. The transmitted power is collected by the chamber horn and measured by a power meter at each measurement angle. Further, the chamber path loss is determined, and thereby can be accounted for by the reference signal, thereby allowing for the determination of the phone&#39;s EIRP. The measured data is stored in real time as the test phone is rotated to the various test angles covering a sphere. Further, tests are done for the chamber horn oriented in both vertical and horizontal polarizations, and thus the vertical and horizontal polarization EIRP patterns are obtained. 
     All three measurements—the transmit EIRP and the primary and secondary antenna receive complex field measurements—are done in sequence at each measurement angle. Hence, all receive and transmit data can be collected with a single test run. 
     Additional details relating to this particular embodiment are discussed below. 
     Referring to  FIG. 2 , wireless device  12  can include any type of computerized, wireless device, such as a cellular telephone, a personal digital assistant, a two-way text pager, and a portable computer. The wireless device can be a remote-slave, or other device that does not have an end-user thereof but simply communicates data across a wireless network. Examples of a remote-slave device include a remote sensor, a diagnostic tool, a data relay, and the like. The functionalities performed on wireless device  12  described herein can accordingly be performed on any form of wireless device or computer module, including, without limitation, wireless modems, PCMCIA cards, wireless access terminals, wireless personal computers, wireless telephones, or any combination or sub-combination thereof. 
     Additionally, wireless device  12  has an input mechanism  52  for generating inputs into wireless device, and output mechanism  54  for generating information for consumption by the user of the wireless device. For example, input mechanism  52  may include a mechanism such as a key or keyboard, a mouse, a touch-screen display, a voice recognition module, etc. The inputs into wireless device may include menu selections to set-up, change parameters, and run a radiated test, or to transfer logged information out of the device. Further, for example, output mechanism  54  may include a display, an audio speaker, a haptic feedback mechanism, etc. The generated information to output may include the above-referenced menus for performing a test and transferring the test results, a view of the test results, etc. 
     Further, wireless device  12  has computer platform  56  that can transmit data across a wireless network, and that can receive and execute software applications and display data transmitted from another computer device connected to the wireless network. Computer platform  56  includes a data repository  58 , which may comprise volatile and nonvolatile memory such as read-only memory (“ROM”) and/or random-access memory (“RAM”), erasable programmable read-only memory (“EPROM”), electronically erasable programmable read-only memory (“EEPROM”), flash memory cards, or any memory common to computer platforms. Further, data repository  58  may include one or more secondary or tertiary storage devices, such as magnetic media, optical media, tape, or soft or hard disk. 
     Further, computer platform  56  also includes a processing engine  60 , which may be an application-specific integrated circuit (“ASIC”), or other chipset, processor, logic circuit, or other data processing device. Processing engine  60  or other processor such as ASIC may execute an application programming interface (“API”) layer  62  that interfaces with any resident programs, such as radiated performance testing module  40 , in data repository  58  of wireless device  12 . API  62  is a runtime environment executing on the respective wireless device. One such runtime environment is Binary Runtime Environment for Wireless® (BREW®) software developed by Qualcomm, Inc., of San Diego, Calif. Other runtime environments may be utilized that, for example, operate to control the execution of applications on wireless computing devices. 
     Processing engine  60  includes various processing subsystems  64  embodied in hardware, firmware, software, and combinations thereof, that enable the functionality of wireless device  12  and the operability of the wireless device on a wireless network. For example, processing subsystems  64  allow for initiating and maintaining communications, and exchanging data, with other networked devices. In one embodiment, such as in a cellular telephone, communications processing engine  60  may include one or a combination of processing subsystems  64 , such as: sound, non-volatile memory, file system, transmit, receive, searcher, layer 1, layer 2, layer 3, main control, remote procedure, handset, power management, diagnostic, digital signal processor, vocoder, messaging, call manager, Bluetooth® system, Bluetooth® LPOS, position determination, position engine, user interface, sleep, data services, security, authentication, universal subscriber identity module/subscriber identity module (“USIM/SIM”), voice services, graphics, universal serial bus (“USB”), multimedia such as moving picture experts group (“MPEG”), general packet radio service (“GPRS”), etc. For the disclosed embodiments, processing subsystems  64  of processing engine  60  may include any subsystem components that interact with applications executing on computer platform  56 . For example, processing subsystems  64  may include any subsystem components which receive data reads and data writes from API  62  on behalf of radiated performance testing module  40 . Further, all or portions of the receiver-related data and/or transmitter-related data that is gathered and then logged by radiated performance testing module  40  is available from these subsystems  64 . 
     Computer platform  56  may further include a communications module  66  embodied in hardware, firmware, software, and combinations thereof, that enables communications among the various components of the wireless device  12 , as well as between wireless device  12  and a wireless network. In one embodiment, for example, communications module  66  includes a transmitter module  68  for wirelessly transmitting information such as radio wave signal  48  through an antenna system  72 , and a receiver module  70  for wirelessly receiving information such as radio wave signal  18  through antenna system  72 . As noted above, antenna system  72  may include a single antenna, such as a monopole antenna, a dipole antenna, a helical antenna, a planar antenna, etc., or any combination thereof to form multiple antennas. For example, such multiple antenna systems may include a multiple-input multiple-output (“MIMO”) communication system, which employs multiple (N T ) transmit antennas and multiple (N R ) receive antennas for data transmission. Alternately, for example, such multiple antenna systems may include a multiple-input single-output (“MISO”) communication system that employs multiple (N T ) transmit antennas and a single receive antenna for data transmission. In any case, receiver module  70  in combination with antenna system  72  may be considered the receive chain of wireless device  12 . Similarly, transmitter module  68  and antenna system  72  may be considered the transmit chain of the wireless device. 
     Additionally, as mentioned above, computer platform  13  further includes radiated performance test module  40  to manage radiated testing-related activities on wireless device  12 . Radiated performance test module  40  may include any hardware, software, firmware and/or other set of executable instructions operable to manage the collection of any information, such as receiver data and/or transmitter data, relating to a radiated performance characteristic  42  of wireless device  12 . Radiated performance test module  40  may be initiated at any time to log, store and make available measured signal characteristic  38 , synchronization data  36 , any transmitter- and/or receiver-related data, and/or any information related to predetermined radiated performance test  24 . 
     In one embodiment, for example, radiated performance test module  40  includes performance logic  74  that provides the capability to collect, store and provide access to, or forward, radiated performance test-related information. Further, in some embodiments, performance logic  74  may initiate the capability of wireless device  12  to generate radiated performance characteristic  42  based on the parameters of a given performance test  24 . 
     Further, radiated performance test module  40  includes a device test configuration  76  that defines log parameters  78  and/or test variables  80  corresponding to predetermined radiated performance test  24  being run by controller system  14 . For example, log parameters  78  define types of information to collect and log as receiver data  82  and/or transmitter data  84  for the given radiated performance test. In one embodiment, for example, log parameters  78  define measured or reference receiver data  82  and/or measured or reference transmitter data  84  available from one or more processing subsystems  64 . In the case of a wireless telephone, for example, log parameters  78  may include log data packets available from processing engine  60  and/or processing subsystem  64 . Examples of the information contained in such log data packets include, but are not limited to: received power from a given receive chain/antenna, transmitted power from a given transmit chain/antenna, in-phase pilot voltages and quadrature-phase pilot voltages associated with a given receive chain, finger lock status, relative delay in a received signal (e.g. the time difference between receiving a first and second instance of the same signal, such as when receiving a reflected signal), etc. In particular, in one embodiment of a CDMA system, such log data packets include the “Search TNG Finger Status” packet, the “RF” subpacket, the “Finger Info” subpacket, and the “Filtered Pilot Symbol” subpacket. Additionally, or alternatively, log parameters  78  may define other radiated performance-related information received by or otherwise accessible to wireless device  12 . For example, in one embodiment, log parameters  78  may include test configuration-related information, and/or information in data packets from signals received by wireless device  12 , such as reference signal characteristic  34  and/or synchronization data  36  from signal  18 . It should be understood, however, that many other log parameters  78  may be defined depending on the nature of the given radiated performance test. 
     Further, for example, test variables  80  define values associated with collecting receiver data  82  and/or transmitter data  84 , and/or performing analysis on the collected data. In one embodiment, for example, types of test variables  80  include a sampling rate, a number of data packets per sample, a code to enable or disable logging, etc. It should be understood, however, that many other test variables  80  may be defined depending on the nature of the given radiated performance test. 
     Additionally, performance logic  74  may execute to prompt a user of wireless device  12  to select a given device test configuration  74 , and/or the associated log parameters  78  and/or test variables  80 , from a plurality of available test configurations, log parameters and/or test variables. For example, referring to  FIGS. 2 and 3 , radiated performance testing module  40  may include a user interface or views  75 , such as a plurality of navigation menus that may be presented to a user via output mechanism  54 . Views  75  may include header information  77  and footer information  79 , such as to identify the given menu, program and/or version. Further, views  75  may present executable commands  81  to enable various functionality associated with a given test. For example, commands  81  may include commands such as: start, to instruct the module to start logging based on the configuration; stop, to instruct the module to stop logging; erase all logs, to erase any logs stored in memory; suspend, to instruct the module to suspend logging, however, the module may include logic to automatically suspend logging if the memory being used reaches a predetermined threshold; resume, to re-initiate logging following a suspend command; release, to release the internal memory buffer, for example, for use for debugging operations; write to memory, to write recorded data from a first memory to a second memory; simulated power down, to cause the device to mimic a normal power down so that clean up functions will be called and executed, which is useful for debugging; request upload, to request an upload of any stored data and/or logs to another computer device, such as controller system  14 ; and audio/vibration, a toggle for setting audio and/or vibrate alert feedback, for example, for use when receiving a command from another device, and/or initiating a data call, and/or when requesting or completing an upload, and for use in debugging operations. Additionally, views  75  may include changeable fields  83 , such as for entering values for test variables  80 . Thus, a user may configure and run a predetermined radiated performance test through views  75  on wireless device  12 . 
     Alternatively, device test configuration  76  may be transmitted to wireless device  12  via a wired or wireless connection, or may be included on computer platform  56  at the time of manufacture. 
     Additionally, radiated performance test module  40  includes device test log  86  for storing the radiated performance-related information based on device test configuration  76 . Device test log  86  comprises a record stored in data repository  58  that may include the test conditions and/or the test results associated with one or more radiated performance tests performed using wireless device  12 . As noted above, for example, device test log  86  may include wireless device (“WD”) receiver data  82  and/or WD transmitter data  84 . In one embodiment, receiver data  82  includes one or more measured signal characteristics  38 , which is/are collected from processing subsystem  64  upon the processing of signal  18  at each selected position  22 . Additionally, device test log  86  may include other information that corresponds to the data generated by wireless device during a given radiated performance test. For instance, device test log  86  may include information contained within a received signal, such as predetermined synchronization data  36  and/or reference signal characteristic  34  from signal  18 . In one embodiment, reference signal data  34  may be data that defines the original state of signal  18  received by wireless device  12 , such as a power value, an amplitude value, a phase value, a frequency value, a signal type/protocol, etc. In one embodiment, predetermined synchronization data  36  may be time information corresponding to a time when wireless device was in selected position  22 , or position information defining the coordinates of selected position  22 . Further, device test log  86  may include all or any portion of device test configuration  76  in association with the collected receiver data  82  and/or transmitter data  84  to provide a convenient reference to the test conditions associated with a given set of collected data. 
     Further, in some embodiments, radiated performance test module  40  may include device analyzer module  88  to determine radiated performance characteristic  42  associated with wireless device  12  for a given predetermined radiated performance test  24 . Device analyzer module  88  may include any hardware, software, firmware and/or other set of executable instructions operable to analyze any information collected in device test log  86  and generate radiated performance characteristic  42 . In one embodiment, for example, device analyzer module  88  may include an analysis protocol  90 , which may include functions, algorithms, etc. associated with a method of processing and/or analyzing the information in log  86  to generate radiated performance characteristic  42 . For example, analysis protocol  90  may include implementations of performance tests, integration protocols, simulation models, predictive models, statistical analysis, etc., such as for utilizing the logged information to determine a desired metric, such as a partial solution to a test result, or the final solution to the test, i.e. the radiated performance characteristic  42 . As such, radiated performance characteristic  42  may be a metric such as, but not limited to, a power and/or voltage gain, a sensitivity measurement, a complex pattern correlation, a fading correlation, a gain differential between two receive chains/antennas, etc. Further, radiated performance test module  40  may store the generated radiated performance characteristic  42  in device test log  86 , or in some other record in association with one or more of the components of log  86 , for transmission, review and/or analysis on wireless device  12  and/or at another computerized device, such as controller system  14 . Additionally, analysis protocol  90  may be contained within device test configuration  76 , and accessed by device analyzer module  88  during execution to determine a radiated performance test result. 
     Referring to FIGS.  1  and  4 - 6 , controller system  14  may comprise at least one of any type of hardware, software, firmware, workstation, server, personal computer, mini computer, mainframe computer, or any special purpose or general computing device. Further, controller system  14  may reside entirely on the wireless device  12 . Additionally, controller system  14  can include separate servers or computer devices that work in concert to perform the functions describe herein. Controller system  14  (or plurality of modules) can send software agents or applications, such as the resident radiated performance testing module  40 , to wireless device  12  across a wireless network, such that wireless device  12  returns information from its resident applications and subsystems. For example, wireless device  12  may transmit the result of executing device test configuration  76  during a predetermined radiated performance test  24  in the form of device test log  86 , where controller system  14  may then synchronize this with predetermined time information or position information to generate radiated performance characteristic  42 . 
     Additionally, controller system  14  has an input mechanism  92  for generating inputs into the system, and an output mechanism  94  for generating information for consumption by the user of the controller system. For example, input mechanism  92  may include a mechanism such as a key or keyboard, a mouse, a touch-screen display, a voice recognition module, etc. The inputs into controller system  14  may include menu selections to set-up, change parameters, and run a radiated test, or to synchronize logged information from the wireless device with logged information on the controller system. Further, for example, output mechanism  94  may include a display, an audio speaker, a haptic feedback mechanism, etc. The generated information to output may include the above-referenced menus for performing a test and synchronizing and/or computing the test results, a view of the test results, etc. 
     Further, controller system  14  has computer platform  96  that can transmit and receive data, and that can receive and execute software applications and cause the display of data. Computer platform  96  includes a storage mechanism  98 , which may comprise volatile and nonvolatile memory such as read-only memory (“ROM”) and/or random-access memory (“RAM”), erasable programmable read-only memory (“EPROM”), electronically erasable programmable read-only memory (“EEPROM”), flash memory cards, or any memory common to computer platforms. Further, storage mechanism  98  may include one or more secondary or tertiary storage devices, such as magnetic media, optical media, tape, or soft or hard disk. 
     Further, computer platform  96  also includes a central processing unit  100 , which may be one or a combination of an application-specific integrated circuit (“ASIC”) or other chipset, a logic circuit, a programmable logic machine, or any other data processing device. Central processing unit  100  interprets and executes instructions and data contained in software, such as all or portions of radiated test manager module  44 , as is discussed below in more detail. 
     Additionally, computer platform  96  further includes a communications module  102  embodied in hardware, firmware, software, and combinations thereof, that enables communications among the various components of controller system  14 , as well as between controller system  14  and other devices, such as positioning system  28 , radio signal system  32 , and wireless device  12 . For example, communications module  102  includes input ports and output ports, such as for receiving device test log  86  and transmitting control signal  16 , respectively. 
     As noted previously, computer platform  96  further includes radiated test manager module  44  to execute and manage all radiated performance test activities on controller system  14 . Radiated test manager module  44  may be embodied in hardware, firmware, software, and combinations thereof. In one embodiment, radiated test manager module  44  includes management logic  104  that provides the capability to run predetermined radiated performance test  24 . Further, in some embodiments, management logic  104  may provide the capability to initiate the analysis of collects logs to generate radiated performance characteristic  24 . 
     In one embodiment, radiated test manager module  44  includes a library  106  having a plurality of predetermined radiated performance tests  108  that may be run by controller system  14 . For example, the plurality of predetermined radiated performance tests  108  may include different test protocols, which can vary by standards body, wireless carrier, wireless device manufacturer, wireless device processor, antenna system, model of wireless device, and also which may be designed to determine different radiated performance characteristics. In any case, management logic  104  may provide an interface to a user to select radiated performance test  24  from among the plurality of predetermined radiated performance tests  108 . Alternately, radiated performance test  24  may be individually loaded onto computer platform  96  and executed by radiated test manager module  44 . 
     Referring to  FIG. 5 , in one embodiment, predetermined radiated performance test  24  includes a set of a plurality of positions  110  at which signals  18  and  46  are respectively transmitted to or from wireless device  12 . The plurality of positions  110  correspond to a particular test protocol. For example, as required by some radiated tests, the plurality of positions  110  may comprise points on a sphere. It should be understood, however, that plurality of positions  110  may comprise points that can be associated with any type of line or any type of shape. As noted previously, associated with each signal  18 ,  46  may be one or more reference signal characteristics  34  and  48 , respectively. These reference signal characteristics  34 ,  48  may include, but are not limited to, a signal power, a signal amplitude, a signal phase, a signal frequency, a signal type/protocol, and any other controllable signal parameter that may be set for purposes of determining a radiated performance of wireless device  12 . 
     Additionally, in some embodiments, each signal  18 ,  46  may further include data packets, which may be defined as predetermined over-the-air (“OTA”) data  112 . For example, as noted above, predetermined OTA data  112  may include predetermined synchronization data  36  that defines time information  114  and/or position information  116 . Time information  114  includes data that defines a time when wireless device  12  is at one of the plurality of positions  110 , such as selected position  22 . In one embodiment, for example, time information  114  may be acquired from a time module  118 , which may be a local module associated with central processing unit  100  or which may be a remote module accessible by controller system  14  for the purposes of synchronizing data. Position information  116  includes data that defines the spatial coordinates of selected position  22 . As previously mentioned, predetermined synchronization data  36  is utilized to associate the measured value, such as measured signal characteristic  38  (received by wireless device  12 ) or measured signal characteristic  50  (received by radio signal system  32 ) at each selected position  22  with for all of the plurality of positions  110  in order to generate a set of measure data for analysis. 
     Further, predetermined OTA data  112  may include additional OTA data  120 , which may include predefined data packets that comprise messages in a given wireless protocol. These messages may include a plurality of subpackets that further define additional data. For example, in a code division multiple access protocol, additional OTA data  120  may include paging messages, acknowledgement messages, registrations messages, system parameter messages, and any other overhead messages. Further, additional OTA data  120  may further include subpacket information such as service options, system identification (“SID”) codes, network identification (“NID”) codes, coordinates of a latitude and longitude of a base station, system configuration/parameter information, test configuration/parameter information, etc. Further, additional OTA data  120  may include codes to control functionality of wireless device  12 , such as to turn logging on and off, to indicate a change of position, to indicate when to transmit a signal, and any other device control parameter. For instance, different SID code values may be used to turn on and turn off the recording of log parameters  78 . Further, in one embodiment, predetermined synchronization data  36  may be embedded in an un-used portion of a standard overhead message defined by additional OTA data  120 . 
     Additionally, predetermined radiated performance test  24  may further include device test configuration  76 , as discussed above in detail. Device test configuration  76  may comprise the relevant information for a computerized device having the appropriate testing modules to execute all or a portion of predetermined radiated performance test  24 . For instance, device test configuration  76  may allow one or both of wireless device  12  and controller system  14  to carry out predetermined radiated performance test  24 . Further, device test configuration  76  may comprise summary information detailing parameters of the test. In one embodiment, for example, device test configuration  76  may be transmitted to wireless device  12  as part of additional OTA data  120 . 
     Additionally, radiated performance test  24  may include a set of log parameters  78  and test variables  80  for executing the test, or for packaging within device test configuration  76 . Also, based on the given parameters of the test, radiated performance test  24  may include a predetermined set of control commands  16  to carry out the test. 
     Further, predetermined radiated performance test  24  may additionally include analysis protocol  90  processing and/or analyzing the information in log  86  to generate radiated performance characteristic  42 , as discussed above in detail. In an embodiment where wireless device  12  performs the analysis, for example, analysis protocol  90  may be transmitted to wireless device  12  as part of additional OTA data  120 . Alternately, analysis protocol  90  may be utilized locally by controller system  14 . 
     Referring back to  FIG. 4 , predetermined radiated performance test  24  is executed by radiated test manager module  44  to generate control signal  16  based on various parameters associated with test  24  at each position. As noted earlier, control signal  16  includes positioning component  26  to move wireless device  12  through each of the plurality of positions  110  via positioning system  28 . Further, as noted earlier, control signal includes signaling component  30  to control the transmissions of signal  18  from radio signal system  32  to wireless device  12  based on reference signal characteristic  34 . 
     In an embodiment, controller system  14  determines radiated performance characteristic  42  of wireless device  12 , such as when wireless device  12  transfers device test log  86  to controller system  14 , or when test  24  involves the measurement of transmission signal  46  from wireless device  12 . In either case, referring to  FIG. 6 , radiated test manager module  44  further includes a control test log  122  to maintain a record of the test conditions and/or the test results. In one embodiment, for example, control test log  122  includes device test configuration  76  to record the test parameters, which may include all or any portion of the data associated with predetermined radiated test  24 , as discussed above. 
     Further, control test log  122  may include the predetermined values of test parameters that can then be compared to the measured values of test parameters in order to determine a radiated performance of wireless device  12 . For example, control test log  122  may include a record of control receiver data  126 , which includes information on signals, such as signal  46 , received by radio signal system  32  from wireless device  12 . For example, control receiver data  126  may include measured signal characteristic  50 , predetermined synchronization data  36 , reference signal characteristic  48 , and/or any other information associated with signal  46  received from wireless device  12 . Similarly, control test log  122  may include a record of control transmitter data  128 , which includes information on signals, such as signal  18 , transmitted by radio signal system  32  to wireless device  12 . For example, control transmitter data  128  may include reference signal characteristic  34 , which defines information about signal  18  transmitted to wireless device  12 , synchronization data  36 , measured signal characteristic  38 , and/or and/or any other information associated with signal  18  transmitted to wireless device  12 . 
     Additionally, in the above embodiments, radiated test manager module  44  may include a performance analyzer module  130  to execute analysis protocol  90 , as discussed above, on the data contained in control test log  122  and/or device test log  86  in order to determine radiated performance characteristic  42 . Performance analyzer module  130 , which may be the same as or similar to analyzer module  88  on wireless device  12 , may include any hardware, software, firmware and/or other set of executable instructions operable to analyze any information collected in control test log  122  and/or device test log  86 . 
     Further, performance analyzer module  130  may additionally include synchronization logic  132  executable to collect control test log  122  and/or device test log  86  and combine records in order to synchronize signals, measurements, and positions in order to generate a synchronized data log  134 . In particular, synchronization logic  132  matches synchronization data  36  between device test log  86  and control test log  122  in order to correspondingly match measured signal characteristics with their associated reference signal characteristics. For example, in one embodiment, the result of this matching combination of records is synchronized data log  134 . In this case, performance analyzer module  130  executes analysis protocol  90  on synchronized data log  134  in order to generate radiated performance characteristic  42 . 
     Referring back to  FIG. 1 , positioning system  28  may be any mechanism capable of moving wireless device  12  to selected position  22 . In one embodiment, for example, positioning system  28  includes a position controller  136  that receives positioning component  26  of control signal  16 , which identifies selected position  22 , and directs a positioner assembly  138  to move an attached wireless device  12  to selected position  22 . For example, positioner assembly  138  may include a plurality of support structures, such as arms and bases, which may each be independently rotatable and/or linearly movable to enable positioner assembly  138  to move wireless device  12  into any given planar and/or spherical position, or to rotate wireless device  12  about an axis through the given position. In one embodiment, for example, positioner assembly  138  may rotate wireless device  12  at any angle θ about a vertical axis and about any angle φ about a horizontal axis. Further, a height of wireless device  12  may be adjusted to any elevation e about a vertical axis. Positioner assembly  138  may include rotational and/or linear motors, such as servo-motors, in order to receive commands from position controller  136  and precisely position wireless device  12 . Further, positioner assembly  138  may include a mounting mechanism  140  for removably securing wireless device  12  to positioner assembly  138 . For example, mounting mechanism  140  may be a corresponding hook and loop fastener system, tape, glue, a slotted case sized to hold the wireless device, etc. 
     Still referring to  FIG. 1 , radio signal system  32  may be any mechanism capable of transmitting and/or receiving radio wave signals respectively to and/or from wireless device  12 . In one embodiment, for example, radio signal system  32  includes a communication simulator module  142  for generating and receiving signals based on signaling component  30  of control command  16 . For example, in an embodiment where wireless device  12  includes a cellular telephone, communication simulator module  142  may be a base station simulator that emulates the functions of a base station transceiver in a wireless network, such as a model 8960 Wireless Communications Test Set available from Agilent Technologies of Palo Alto, Calif. Communication simulator module  142  may include transmit and receive components that enable radio signal system  32  to transmit signal  18  and receive signal  48  through an antenna  144 . In one embodiment, antenna  144  includes a direction horn-type antenna, which may include a positioner  146  to adjust a horizontal h and/or vertical v polarization associated with the signals. Additionally, positioner  146  may be able to adjust a vertical height of antenna  144 , although this may not be necessary if the vertical height of wireless device  12  is adjustable by positioner assembly  138 . 
     Additionally, as noted above, communication simulator module  142  may include receive components to measure predetermined parameters of received signal  46 . Alternatively, radio signal system  32  may include additional receiver components  148 , such as a power meter, to measure parameters of interest. In any case, radio signal system  32  measures the received signal  46  and reports this information to controller system  14 . For example, radio signal system  32  reports control receiver data  126 , such as measured signal characteristic  50 , to controller system  14 , which records this information in control test log  122  ( FIGS. 4 and 6 ). 
     Still referring to  FIG. 1 , test chamber  20  provides an environment that isolates wireless device  12  from external radio waves and noise. Further, test chamber  20  provides an environment that reduces interference from reflected radio wave signals, and thus may comprise an anechoic chamber. For example, test chamber  20  includes a plurality of walls  150  that form an enclosure surrounding wireless device  12 . The internally-facing sides of walls  150  include wave absorbing materials  152 , such as a foam material having a plurality of cone-shaped projections for absorbing and dissipating radio waves and noise. Further, any component within test chamber  20 , such as positioning assembly  138 , may further include wave absorbing material  152  on one or more surfaces to reduce radio wave reflection. Thus, test chamber  20  provides radio frequency (“RF”) isolation from the external environment and allows for the execution of radiated tests on the same frequency channels used by local wireless carriers without interference, such as interference to or from the commercial wireless networks. 
     Referring to  FIG. 7 , in one embodiment, a method operable on a wireless device for determining a radiated performance characteristic of the wireless device comprises receiving and loading a radiated performance testing module (Block  160 ). For example, wireless device  12  may receive and load radiated performance testing module  40  via a wired or wireless connection. 
     Further, the method may further include receiving a test configuration associated with the predetermined radiated performance test (Block  162 ). For example, wireless device  12  may receive device test configuration  76  which identifies parameters  78  to log and variables  80  to utilize during the performance of the given radiated performance test. 
     Additionally, the method may further include executing the given radiated performance test based on the received test configuration (Block  164 ). Execution of the given radiated performance test may involve a number of actions, such as receiving a radio wave signal (Block  166 ), transmitting a radio wave signal (Block  168 ), and/or logging measured and/or reference signal characteristics and synchronization data based on the received test configuration at each of a plurality of positions defined by the predetermined radiated performance test (Block  170 ). For example, when testing the received capabilities of wireless device  12 , radiated performance testing module  40  records receiver data  82 , such as measured signal characteristic  38 , based on the device test configuration  76 . Similarly, radiated performance testing module  40  may transmit signal  46  and log its associated reference signal characteristic  48  based on the parameters of the given radiated performance test  24 . 
     In an embodiment that involves local analysis (Block  172 ), the method further includes receiving and loading an analysis protocol associated with a given radiated performance test (Block  174 ). For example, radiated performance testing module  40  may receive an analysis protocol  90  to apply to the recorded log information in device test log  86 . Further, this embodiment includes analyzing the logged measured and/or reference signal characteristics and synchronization data (Block  176 ), and generating a radiated performance characteristic based on the analysis protocol (Block  178 ). For example radiated performance testing module  40  executes analysis protocol  90  to analyze predetermined parameters recorded within device test log  86 . This analysis results in a generation of radiated performance characteristic  42 . 
     Alternatively, in an embodiment that provides for remote analysis (Block  172 ), the method further includes transferring the log records so that they may be analyzed by another device (Block  180 ). For example, radiated performance testing module  40  transfers device test log  86  to controller system  14  for further analysis. 
     Referring to  FIG. 8 , in another embodiment, a method operable on an apparatus for determining a radiated performance characteristic of a wireless device includes receiving and loading a radiated performance application (Block  182 ). For example, controller system  14  may receive and the load radiated test manager module  44  having one or more radiated performance tests. 
     Further, the method includes executing a predetermined radiated performance test (Block  184 ). For example, radiated test manager module  44  may execute predetermined radiated performance test  24 . The execution of a predetermined radiated performance test may involve a number of actions, such as sending control signals based on the predetermined test to other system components (Block  186 ). For example, at each of a plurality of positions  110  associated with a given performance test  24 , radiated test manager module  44  may generate control signal  16  having positioning component  26  to change the position of wireless device  12  through movements of positioning system  28 . In embodiments involving the transmission of signals to wireless device  12 , the action of sending control signals may further include sending a signaling component  30  to radio signal system  32  to initiate generation of signal  18 . Additionally, for example, the action of executing a predetermined radiated performance test may further involve logging predetermined reference and/or measured signal characteristics and synchronization data (Block  188 ). For example, radiated test manager module  44  may record control receiver data  126  and/or control transmitter data  128  in control test log  122 . 
     In an embodiment that involves local analysis (Block  190 ), the method further includes receiving a record of measured characteristics and synchronization data from the wireless device (Block  192 ). For example, radiated test manager module  44  receives device test log  86  from wireless device  12 . If that the received log includes measured signal characteristics that are synchronized with position information (Block  194 ), then the method further includes analyzing the received log based on a predetermined analysis protocol (Block  196 ) and generating a radiated performance characteristic (Block  198 ). For example, performance analyzer module  130  may analyze device test log  86  using analysis protocol  90  to determine radiated performance characteristic  42 . Alternatively, if the received log is not synchronized (Block  194 ), then the method includes synchronizing the received log information with local log information to generate a synchronized data log (Block  200 ). For example performance analyzer module  130  may execute synchronization logic  132  to combine device test log  86  with control test log  122  by matching the synchronization information contained within each log. In this case, once synchronize data log  134  is generated, then the method may continue with the analysis of the synchronized information via a predetermined analysis protocol (Block  196 ) and the generation of radiated performance characteristic  42  (Block  198 ). 
     Alternatively, in an embodiment that involves remote analysis (Block  190 ), such as analysis on wireless device  12 , the method may include transmitting an analysis protocol associated with the predetermined radiated test to another device (Block  198 ). For example, if not already included as part of device test configuration  76 , radiated test manager module  44  may transmit analysis protocol  90  to wireless device  12 , such as through signal  18 . Optionally, this embodiment of the method may further include receiving the radiated performance characteristic from another device (Block  200 ). For example, radiated test manager module  44  may receive radiated performance characteristic  42  from wireless device  12  if the wireless device includes analyzer module  88 . 
     In particular, in one non-limiting example as highlighted earlier, the described embodiments may be utilized for cellular telephone radiated antenna/receiver tests, such as: (1) a Total Isotropic Sensitivity (TIS) test; (2) a Total Radiated Power (TRP) test; and (3) an antenna pattern correlation (rho) test. 
     All three of these radiated tests require spherical measurement of antenna gain for both vertical and horizontal polarizations. Inherent in the TIS test is a measurement of the antenna receive gain pattern, although it is traditionally accomplished indirectly via receiver sensitivity. The TRP test depends on a measurement of the antenna&#39;s transmit gain. The antenna pattern correlation test, or antenna rho test, requires simultaneous measurement of complex voltage receive (“RX”) gain, including amplitude and phase, of two or more antennas. The physical procedure of measuring spherical gain is essentially the same for all tests: measure the loss between transmitter and receiver as the phone is physically rotated around the sphere, most commonly in a series of Great Circle cuts (elevation cuts). What differs between each test is the nature and position of the transmitter and receiver. 
     In the case of the TIS test and antenna pattern correlation test, the transmitter, typically a cell-site simulator such a communication simulator module  142 , is connected to a range directional antenna such as a horn antenna  144 , and the receiver is connected to the antenna under test. In this case, the receiver is receiver module  70  and the antenna under test is antenna system  72  of wireless device  12 . For the TRP test, wireless device  12  acts as the transmitter, and the receiver is an RF power meter  148  connected to the range antenna  144 . 
     In these tests, receiver module  70  of wireless device  12  makes the necessary measurements for the RX-based tests (RX Gain, Antenna Rho). By using receiver module  70  of wireless device  12 , the described embodiments provide a number of advantages, such as: time savings, since wireless device  12  does not have to be modified for testing; and, potentially, more accurate results since the prior art modification of wireless device  12  and the prior art use of external equipment and cables may alter the gain pattern of the antenna. 
     Additionally, radiated performance testing module  40  provides access to receiver data  82 , such as RX_AGC (received power) and Pilot I/Q estimates from each rake finger via API  62  interfacing with processing subsystems  64 . Further, radiated performance testing module  40  logs receiver data  82  to device test log  74  within data repository  58 . This approach provides the advantage of being able to test wireless device  12  with no cables attached. At this point, wireless device  12  becomes both the test equipment and the data logger. This provides a cleaner test setup which evaluates wireless device  12  in a more representative state (uncabled) and may provide time savings as well. 
     Further, the above-described set-up allows all necessary test data to be logged in one single place—one wireless device  12 . For example, with system  10 , position controller  136  can be queried for position information at the time of each power measurement. This position information, or some data (such as a time) corresponding to this position information, is communicated to wireless device  12  during testing (without cables) such that all necessary test data can be logged on wireless device  12 . This enables wireless device  12  to synchronously log position information with receiver parameters such that a power vs. position record can be collected on the fly. Alternatively, controller system  14  may record the position information and a time, or some other variable that can be synchronized with wireless device  12 , corresponding to the position information. At the same time, wireless device  12  records the measured data parameter and the time (or other synchronization data). In this alternative, wireless device  12  may send the log to controller system  14 , which can synchronize the position information with the measured data parameters via the time, or other synchronization data. For example, position information, or at least synchronization data  36 , may be transmitted to wireless device  12  via: a data socket opened over an active traffic channel, encoding in one or more unused fields in the forward link overhead channel messages, such as the SID, network identification (“NID”), or base station latitude and longitude in system parameter message; and, data could be communicated over auxiliary channels such as Bluetooth® or 802.11 frequency channels. 
     The TIS test accounts for interaction of antenna and phone electronics, inclusive of jamming effects from unwanted noise radiated by phone electronics that can couple to the antenna module. In particular, with regard to the TIS test, a CDMA receiver sensitivity measurement entails finding the traffic channel power at which the received signal quality begins to degrade; specifically, the point at which the frame error rate (FER) becomes 0.5%. It should be noted, however, that some other FER threshold may be specified, depending on the given scenario. Further, it should be noted that other threshold parameters may be utilized. For example, utilizing global system for mobile communications (“GSM”) technology, the threshold parameter may be bit error rate (“BER”). For the CDMA case, however, the Cellular Telecommunications &amp; Internet Association (“CTIA”)-specified procedure for the TIS test dictates that a radiated sensitivity measurement is made at every 30° in the Theta (elevation) and Phi (azimuth) axes. Again, depending on the scenario, other predetermined positions may be utilized. Excluding points at Theta=0° and 180°, this prior art technique requires 60 individual sensitivity measurements for each polarization, which are subsequently integrated over the sphere, producing the TIS metric. This is an extremely time consuming test to perform, since identification of the sensitivity point at each position requires a gradual, iterative process, which in the past has been performed manually. 
     The described embodiments, however, provide for accelerating the speed at which the TIS test can be performed. The radiated sensitivity around the sphere varies only as a result of the variation of antenna RX gain. All other factors in the link are constant. As such, it follows that if the antenna&#39;s RX gain pattern is known, then a sensitivity measurement is required at only a single reference point, preferably the point of maximum antenna gain. Therefore, radiated sensitivity, Sens, at any other point (θ, φ) on the sphere can be expressed as: 
       Sens(θ,φ)=Sens(θ o ,φ o )+[ G   RX (θ,φ)− G   RX (θ o ,φ o )]  (1)
 
     where Sens(θ, φ) is the radiated sensitivity at spherical coordinate (θ, φ), expressed in dBm, G RX  (θ, φ) is the RX antenna gain at spherical coordinate (θ, φ), expressed in dB, and (θ o , φ o ) is the coordinate of the reference sensitivity measurement, i.e. preferably the sensitivity at the position of maximum gain. 
     In the prior art, this approach is impractical, since as mentioned previously, prior art devices are altered destructively to measure G RX  (θ, φ). However, the described embodiments allow G RX  (θ, φ) to be determined non-destructively, since received power measurements are performed by receiver module  70  of wireless device  12 . Thus, in one particular embodiment, the following accelerated methodology for each polarization (vertical and horizontal) may be utilized: 
     (1) execute radiated performance testing module  40  to measure and log G RX  (θ, φ) at a predetermined plurality of positions, such as 30° increments for (θ, φ) which in this case defines a shape of a sphere, (excluding θ=0° and 180°); 
     (2) identify the position, (θ o , φ o ), at which G RX  is maximum; 
     (3) perform a single radiated sensitivity test at position (θ o , φ o ), i.e. ramping down transmitted power to the wireless device while monitoring FER (or BER for a GSM-based device) until a predetermined threshold FER is reached, to determine Sens (θ o , φ o ); 
     (4) apply Equation 1 above to the entire set of predetermined positions, such as the previously-mentioned spherical positions, to determine Sens(θ, φ) for each predetermined position; and 
     (5) integrate the calculated Sens(θ, φ) over the shape of the predetermined positions in order to determine the TIS metric for the wireless device. 
     In other words, TIS requires “radiated sensitivity patterns” EIS v  (θ, φ) and EIS h  (θ, φ), where EIS v or h  (Effective Isotropic Sensitivity) is the radiated receiver sensitivity at a given measurement angle (θ, φ) for a given BER or FER threshold. In a test chamber, however, these values are difficult to measure directly since the call often drops when the test phone is rotated to an antenna pattern null (e.g., the receive signal level can go below phone noise level). To avoid this problem, the receive patterns are measured at a received power level high enough to avoid dropped calls, and then scaled by the measured peak sensitivity value to derive EIS v  (θ, φ) and EIS h  (θ, φ) patterns. For example, in one embodiment, the chamber path losses are calibrated so that a known power level is incident on the test phone that is about equal to or greater than 30 dB above the phone&#39;s noise floor (e.g., about −70 dBm at the phone test site is a good number for a typical phone). It should be noted, however, that other dBm values may be utilized depending on the given test scenario. The antenna gain patterns (G v  (θ, φ), G h  (θ, φ))) are derived from the above measured pattern data by normalizing to the received signal strength indication (“RSSI”) value, i.e. the measured power, reported by the phone when “injecting” the reference power level (−70 dBm in this case) directly into the receiver (usually via the RF test port on the phone). This is the value the phone would report if the antenna gain at a given measurement angle was 0 dBi and the power incident at the phone was −70 dBm. Deviations from this value indicate the receive antenna gain. 
     The peak radiated receiver sensitivity, Peak EIS (θ pk , φ pk ), is then measured in the anechoic chamber at the angle of incidence (θ, φ) and for the chamber horn polarization (vertical, v, or horizontal, h) resulting in the peak antenna gain. The EIS patterns are obtained by normalizing the antenna gain patterns by the peak EIS value: 
       EIS v or h (θ,φ)=PeakEIS(θ pk ,φ pk )− G   v or h (θ,φ).
 
     Once the EIS v  (θ, φ) and EIS h  (θ, φ) patterns are known, the TIS metric is obtained by performing a spatial average of the patterns over a sphere of test angles: 
     
       
         
           
             TIS 
             = 
             
               
                 4 
                  
                 π 
               
               
                 ∯ 
                 
                   
                     
                       { 
                       
                         
                           
                             EIS 
                             v 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                         + 
                         
                           
                             EIS 
                             h 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                       
                       } 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     
                        
                       θ 
                     
                   
                    
                   
                      
                     φ 
                   
                 
               
             
           
         
       
     
     This technique allows for the calculations to be made entirely on wireless device  12 , entirely at control system  14 , or some combination thereof. For example, wireless device  12  can independently make determinations when in receipt of synchronization data  26 , such as position information, or synchronization data  26  such as time information  114  in combination with the log from controller system  14  of synchronization data  26  versus position information. Wireless device  12  may determine) G RX  (θ o , φ o ) and transmit position (θ o , φ o ) to controller system  14  for re-orientation of positioning system  28  and initiation of the sensitivity testing portion of the protocol. Wireless device  12  may then calculate the required Sens(θ, φ), and perform the integration to determine the TIS metric, which it may store and/or send to controller system  14 . 
     Alternatively, the data collection at wireless device  12  may be interrupted after Steps  1  and  2  to allow device test log  86  to be offloaded from wireless device  12  to, for example, controller system  14  for post-processing to determine G RX  (θ, φ) and G RX  (θ o , φ o ). For example, log  86  includes a record of measured data versus synchronization data At this point, controller system  14  may send control signal  16  to position wireless device at position (θ o , φ o ) for the radiated sensitivity test. Similarly, wireless device  12  may offload device test log  86  after recording a set of sensitivity measurements at the position of maximum gain, or after determining Sens(θ o , φ o ). Then, controller system  14  can apply Equation 1 at all positions and/or perform the integration across the sphere, thereby determining the TIS metric. 
     Furthermore, Step  1  can be performed with wireless device  12  in idle mode, since the RX_AGC is active. Advantageously, this technique eliminates the need to maintain a traffic call during the duration of the test. Although, it should be noted that wireless device  12  may be in a call for Step  3 , since FER may be defined only for traffic data frames. 
     In one embodiment, the above-described sensitivity test is performed manually—the forward link transmit power on the cell-site simulator is adjusted by hand to reach the target FER on wireless device  12 . As noted above, the described embodiments provide for the automation of the sensitivity test. For example, controller system  14  establishes a call with wireless device  12  and gradually ramps the forward link power down while maintaining a record of power vs. time, i.e. in control test log  122 . Simultaneously, radiated performance testing module  40  records FER vs. time, i.e. in device test log  86 . Radiated test manager module  44  receives device test log  86  and executes synchronization logic  132  to synchronize the measurements associated with the recorded time in each log  122  and  86 , thereby generating synchronized log  134  which includes a record of FER vs. power. Based on this record of FER vs. power, performance analyzer module  130  may determine the point of 0.5% FER. 
     In another alternative, if the forward transmit power is communicated to wireless device  12  over the forward link, then all necessary data can be logged at the wireless device  12 . In this case, radiated performance testing module  40  executes analyzer module  88  to determine the point of 0.5% FER. Thus, consolidating the logging on wireless device  12  advantageously eliminates the need for offline synchronization of logs  122  and  86  respectively from controller system  14  and wireless device  12 . 
     With regard TRP, the TRP test is a performance test of the transmit chain of wireless device  12 . For this test, wireless device  12  may be configured via device test configuration  76  to transmit at full power. For example, in a CDMA device, this is most often accomplished by instructing the cell-site simulator to send “all-up” power control bits while a traffic call is maintained. Power received from wireless device  12  is measured by power meter  148  attached to antenna range directional (horn) antenna  144 . 
     The CTIA-specified procedure for the TRP test dictates that a power measurement is made at every 15° in the Theta (elevation) and Phi (azimuth) axes for each polarization. Excluding points at Theta=0° and 180°, this technique requires 264 individual data points for each polarization, which are subsequently integrated over the sphere, producing the TRP metric. Due to the overlap in the positions at which measurements are desired, the described embodiments allow the TRP test to be performed simultaneously with the TIS test, thereby providing substantial time savings. 
     Alternatively, another method to configure wireless device  12  for full-power operation is to manually set the digital transmit gain by placing it in Factory Test Mode (FTM). In this configuration, the TRP test can be performed simultaneously with the idle mode RX gain determination described above with regard to the TIS test, providing for potential time savings. 
     In other words, the TRP metric may be determined by the following equation: 
     
       
         
           
             TRP 
             = 
             
               
                 1 
                 
                   4 
                    
                   π 
                 
               
               · 
               
                 ∯ 
                 
                   
                     
                       [ 
                       
                         
                           
                             EIRP 
                             v 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                         + 
                         
                           
                             EIRP 
                             h 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                       
                       ] 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     
                        
                       θ 
                     
                   
                    
                   
                      
                     φ 
                   
                 
               
             
           
         
       
     
     where EIRP v (θ, φ) is the effective isotropic radiated power for the vertical polarization, and EIRP h (θ, φ) is the effective isotropic radiated power for the horizontal polarization, which can be determined from the transmit gain patterns, G v or h (θ, φ): 
         G   v or h (θ,φ)=EIRP v or h (θ,φ)/MaxPAOut
 
     where MaxPAOut is the maximum power out of the power amplifier, i.e. the maximum power out of transmitter module  68 , at each test frequency. 
     It follows that the peak effective radiated power, PeakEIRP, is the maximum value of the EIRP pattern: 
       PeakEIRP=Max[Max(EIRP v (θ,φ)),Max(EIRP h (θ,φ))]
 
     The PeakEIRP may be needed for regulatory certification of a wireless device, i.e., SAR, class level certification, radiated emissions. 
     Further, another transmit mode radiated performance characteristic is the antenna efficiency, η: 
     
       
         
           
             η 
             = 
             
               
                 1 
                 
                   4 
                    
                   π 
                 
               
               · 
               
                 ∯ 
                 
                   
                     
                       [ 
                       
                         
                           
                             G 
                             v 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                         + 
                         
                           
                             G 
                             h 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                       
                       ] 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     
                        
                       θ 
                     
                   
                    
                   
                      
                     φ 
                   
                 
               
             
           
         
       
     
     which is derived in a manner similar to deriving TRP from the antenna gain patterns. 
     Pattern envelope correlation, ρ e , evaluates the potential for diversity gains of a dual antenna, dual receiver phone in a mobile environment. The rho test determines fading correlation based on measuring complex gains. The measured complex Rx patterns for the primary and secondary antennas (e.g., Eθ1, Eφ1, Eθ2, Eφ2, as discussed below) can be used to estimate the envelope correlation resulting from a model of the incident field on the antenna pair. 
     With the advent of receiver diversity as an available feature in current-generation of mobile station modem (“MSM”) ASICs, a need has developed for radiated tests to predict how well a multi-antenna system will perform in the field. MIMO devices will benefit from such a test as well. A crucial design parameter for a dual-antenna device is the correlation between antennas. An antenna pair which produces highly correlated signals in the dual receive chains is of minimal use for receive diversity. The described embodiments utilize the envelope correlation, also known as the fading correlation, as a predictor of diversity gain in dual antenna systems. 
     The envelope correlation can be predicted from complex voltage gain patterns of a pair of antennas and an assumed incident RF field. As with other receive gain measurements, the complex antenna gain pattern has traditionally been measured using a cabled test. In the case of a commercial wireless device, this requires destructive modification of the device to install external connectors. Instead of destructive modification, however, the described embodiments utilize component of receiver module  70  of wireless device  12 . For example, in the case of a cellular phone, the CDMA rake receiver functionality requires accurate phase estimates of the Pilot channel. By providing an active Pilot channel from a cell-site simulator, such as simulator  142 , and having radiated performance test module  40  log the received power from each receive chain/antenna, as may be found in an RX_AGC data packet, and the in-phase/quadrature-phase (I/Q) Pilot estimates, as may be found in a RX_Pilot Finger data packet, from the rake receiver as the phone is rotated around a sphere, a complex gain pattern can be generated entirely on wireless device  12 . This requires no destructive modification of the handset. 
     As with the receiver gain pattern discussed above, all logging may be consolidated on wireless device  12  if position/angle information is wirelessly transmitted to the device, such as over the forward link, during data collection. 
     If wireless device  12  does not accurately implement receiver diversity in Idle mode, multi-antenna complex pattern determination may be accomplished with wireless device  12  in a traffic call. 
     In particular, the described embodiments include apparatus and methods for estimating the envelope fading correlation ρ e  in a mobile environment from the measured complex radiated patterns from a pair of antennas on wireless device  12  within test chamber  20 . 
     The complex voltage V incident on an m th  antenna element at (θ, φ) due to the k th  electromagnetic plane wave (ray), F k   m  (θ, φ) with a complex antenna field pattern, E m  (θ, φ), can be given by: 
     
       
         
           
             
               
                 
                   
                     V 
                     m 
                     k 
                   
                   = 
                     
                    
                   
                     
                       ∫ 
                       0 
                       
                         2 
                          
                         π 
                       
                     
                      
                     
                       
                         ∫ 
                         0 
                         π 
                       
                        
                       
                         
                           
                             
                               E 
                               m 
                             
                              
                             
                               ( 
                               
                                 θ 
                                 , 
                                 φ 
                               
                               ) 
                             
                           
                           · 
                           
                             
                               F 
                               m 
                               k 
                             
                              
                             
                               ( 
                               
                                 θ 
                                 , 
                                 φ 
                               
                               ) 
                             
                           
                           · 
                           sin 
                         
                          
                         
                             
                         
                          
                         
                           θ 
                           · 
                           
                              
                             θ 
                           
                           · 
                           
                              
                             φ 
                           
                         
                       
                     
                   
                 
               
             
             
               
                 
                   = 
                     
                    
                   
                     
                       ∫ 
                       0 
                       
                         2 
                          
                         π 
                       
                     
                      
                     
                       
                         ∫ 
                         0 
                         π 
                       
                        
                       
                         
                           
                             ( 
                             
                               
                                 
                                   
                                     
                                       
                                         
                                           
                                             E 
                                             
                                               θ 
                                               , 
                                               m 
                                             
                                           
                                            
                                           
                                             ( 
                                             
                                               θ 
                                               , 
                                               φ 
                                             
                                             ) 
                                           
                                         
                                         · 
                                         
                                           F 
                                           
                                             θ 
                                             , 
                                             m 
                                           
                                           k 
                                         
                                       
                                        
                                       
                                         ( 
                                         
                                           θ 
                                           , 
                                           φ 
                                         
                                         ) 
                                       
                                     
                                     + 
                                   
                                 
                               
                               
                                 
                                   
                                     
                                       
                                         E 
                                         
                                           φ 
                                           , 
                                           m 
                                         
                                       
                                        
                                       
                                         ( 
                                         
                                           θ 
                                           , 
                                           φ 
                                         
                                         ) 
                                       
                                     
                                     · 
                                     
                                       
                                         F 
                                         
                                           φ 
                                           , 
                                           m 
                                         
                                         k 
                                       
                                        
                                       
                                         ( 
                                         
                                           θ 
                                           , 
                                           φ 
                                         
                                         ) 
                                       
                                     
                                   
                                 
                               
                             
                             ) 
                           
                           · 
                           sin 
                         
                          
                         
                             
                         
                          
                         
                           θ 
                           · 
                           
                              
                             θ 
                           
                           · 
                           
                              
                             φ 
                           
                         
                       
                     
                   
                 
               
             
           
         
       
     
     Then, the variance in the total complex antenna field pattern at this antenna element, E[|V m   k | 2 ] is: 
     
       
         
           
             
               E 
                
               
                 [ 
                 
                   
                      
                     
                       V 
                       m 
                       k 
                     
                      
                   
                   2 
                 
                 ] 
               
             
             = 
             
               
                 
                   P 
                   V 
                 
                 · 
                 
                   
                     ∫ 
                     0 
                     
                       2 
                        
                       π 
                     
                   
                    
                   
                     
                       ∫ 
                       0 
                       π 
                     
                      
                     
                       
                         
                           
                              
                             
                               
                                 E 
                                 
                                   θ 
                                   , 
                                   m 
                                 
                               
                                
                               
                                 ( 
                                 
                                   θ 
                                   , 
                                   φ 
                                 
                                 ) 
                               
                             
                              
                           
                           2 
                         
                         · 
                         
                           
                             P 
                             θ 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                         · 
                         sin 
                       
                        
                       
                           
                       
                        
                       
                         θ 
                         · 
                         
                            
                           θ 
                         
                         · 
                         
                            
                           φ 
                         
                       
                     
                   
                 
               
               + 
               
                 
                   P 
                   H 
                 
                 · 
                 
                   
                     ∫ 
                     0 
                     
                       2 
                        
                       π 
                     
                   
                    
                   
                     
                       ∫ 
                       0 
                       π 
                     
                      
                     
                       
                         
                           
                              
                             
                               
                                 E 
                                 
                                   φ 
                                   , 
                                   m 
                                 
                               
                                
                               
                                 ( 
                                 
                                   θ 
                                   , 
                                   φ 
                                 
                                 ) 
                               
                             
                              
                           
                           2 
                         
                         · 
                         
                           
                             P 
                             φ 
                           
                            
                           
                             ( 
                             
                               θ 
                               , 
                               φ 
                             
                             ) 
                           
                         
                         · 
                         sin 
                       
                        
                       
                           
                       
                        
                       
                         θ 
                         · 
                         
                            
                           θ 
                         
                         · 
                         
                            
                           φ 
                         
                       
                     
                   
                 
               
             
           
         
       
     
     where P θ  and P φ  represent the incident field angular power density functions in θ (vertical polarization) and φ (horizontal polarization) directions, P V  and P H  are constants representing the mean incident powers on wireless device  12  in θ (vertical) and φ (horizontal) polarizations, respectively, over a representative RF environment, such as may be found along a random drive route. 
     For antennas  1  and  2 , the cross covariance, E└V 1   k ·V 2   k *┘, between received signals from the two antennas is: 
     
       
         
           
             
               
                 
                   
                     E 
                      
                     
                       [ 
                       
                         
                           V 
                           1 
                           k 
                         
                         · 
                         
                           V 
                           2 
                           
                             k 
                             * 
                           
                         
                       
                       ] 
                     
                   
                   = 
                     
                    
                   
                     
                       E 
                        
                       
                         [ 
                         
                           
                             V 
                             
                               θ 
                               , 
                               1 
                             
                             k 
                           
                           · 
                           
                             V 
                             
                               θ 
                               , 
                               2 
                             
                             
                               k 
                               * 
                             
                           
                         
                         ] 
                       
                     
                     + 
                     
                       E 
                        
                       
                         [ 
                         
                           
                             V 
                             
                               φ 
                               , 
                               1 
                             
                             k 
                           
                           · 
                           
                             V 
                             
                               φ 
                               , 
                               2 
                             
                             
                               k 
                               * 
                             
                           
                         
                         ] 
                       
                     
                   
                 
               
             
             
               
                 
                   = 
                     
                    
                   
                     
                       P 
                       H 
                     
                     · 
                     
                       
                         ∫ 
                         0 
                         
                           2 
                            
                           π 
                         
                       
                        
                       
                         
                           ∫ 
                           0 
                           π 
                         
                          
                         
                           
                             ( 
                             
                               
                                 
                                   
                                     
                                       XPR 
                                       · 
                                       
                                         E 
                                         
                                           θ 
                                           , 
                                           1 
                                         
                                       
                                     
                                      
                                     
                                       
                                         ( 
                                         
                                           θ 
                                           , 
                                           φ 
                                         
                                         ) 
                                       
                                       · 
                                     
                                   
                                 
                               
                               
                                 
                                   
                                     
                                       
                                         
                                           
                                             
                                               
                                                 E 
                                                 
                                                   θ 
                                                   , 
                                                   2 
                                                 
                                                 * 
                                               
                                                
                                               
                                                 ( 
                                                 
                                                   θ 
                                                   , 
                                                   φ 
                                                 
                                                 ) 
                                               
                                             
                                             · 
                                             
                                               
                                                 P 
                                                 θ 
                                               
                                                
                                               
                                                 ( 
                                                 
                                                   θ 
                                                   , 
                                                   φ 
                                                 
                                                 ) 
                                               
                                             
                                           
                                           + 
                                         
                                       
                                     
                                     
                                       
                                         
                                           
                                             
                                               E 
                                               
                                                 φ 
                                                 , 
                                                 1 
                                               
                                             
                                              
                                             
                                               ( 
                                               
                                                 θ 
                                                 , 
                                                 φ 
                                               
                                               ) 
                                             
                                           
                                           · 
                                           
                                             
                                               E 
                                               
                                                 φ 
                                                 , 
                                                 2 
                                               
                                               * 
                                             
                                              
                                             
                                               ( 
                                               
                                                 θ 
                                                 , 
                                                 φ 
                                               
                                               ) 
                                             
                                           
                                           · 
                                         
                                       
                                     
                                     
                                       
                                         
                                           
                                             P 
                                             φ 
                                           
                                            
                                           
                                             ( 
                                             
                                               θ 
                                               , 
                                               φ 
                                             
                                             ) 
                                           
                                         
                                       
                                     
                                   
                                 
                               
                             
                             ) 
                           
                           · 
                         
                       
                     
                   
                 
               
             
             
               
                 
                     
                    
                   
                     sin 
                      
                     
                         
                     
                      
                     
                       θ 
                       · 
                       
                          
                         θ 
                       
                       · 
                       
                          
                         φ 
                       
                     
                   
                 
               
             
           
         
       
     
     where XPR=P V /P H , and where * indicates the complex conjugate. 
     From the two signal variances and the cross covariance, the envelope correlation coefficient is given by: 
     
       
         
           
             
               
                 ρ 
                 e 
               
               ≅ 
               
                 
                    
                   ρ 
                    
                 
                 2 
               
             
             = 
             
               
                 
                    
                   
                     E 
                      
                     
                       [ 
                       
                         
                           V 
                           1 
                           k 
                         
                         · 
                         
                           V 
                           2 
                           
                             k 
                             * 
                           
                         
                       
                       ] 
                     
                   
                    
                 
                 2 
               
               
                 
                   E 
                    
                   
                     [ 
                     
                       
                         V 
                         1 
                         k 
                       
                       · 
                       
                         V 
                         1 
                         
                           k 
                           * 
                         
                       
                     
                     ] 
                   
                 
                 · 
                 
                   E 
                    
                   
                     [ 
                     
                       
                         V 
                         2 
                         k 
                       
                       · 
                       
                         V 
                         2 
                         
                           k 
                           * 
                         
                       
                     
                     ] 
                   
                 
               
             
           
         
       
     
     The measured complex antenna patterns, Eθ1, Eφ1, Eθ2, Eφ2, for wireless device  12  having antenna system  72  with dual antennas at discrete angles over a field of view covering 4π steradians can be used in the previous formulation to calculate ρ e  as follows: 
     
       
         
           
             
               R 
               12 
             
             = 
             
               
                 ∑ 
                 
                   j 
                   = 
                   1 
                 
                 
                   N 
                    
                   
                       
                   
                    
                   φ 
                 
               
                
               
                 
                   ∑ 
                   
                     i 
                     = 
                     1 
                   
                   
                     N 
                      
                     
                         
                     
                      
                     θ 
                   
                 
                  
                 
                   
                     
                       ( 
                       
                         
                           
                             XPR 
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           
                             θ 
                             i 
                           
                         
                         + 
                         
                           E 
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           i 
                         
                       
                       ) 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     
                       θ 
                       i 
                     
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   φ 
                 
               
             
           
         
       
       
         
           
             
               σ 
                
               
                   
               
                
               1 
             
             = 
             
               
                 ∑ 
                 
                   j 
                   = 
                   1 
                 
                 
                   N 
                    
                   
                       
                   
                    
                   φ 
                 
               
                
               
                 
                   ∑ 
                   
                     i 
                     = 
                     1 
                   
                   
                     N 
                      
                     
                         
                     
                      
                     θ 
                   
                 
                  
                 
                   
                     
                       ( 
                       
                         
                           
                             XPR 
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           
                             θ 
                             i 
                           
                         
                         + 
                         
                           E 
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               1 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           
                             φ 
                             i 
                           
                         
                       
                       ) 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     
                       θ 
                       i 
                     
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   φ 
                 
               
             
           
         
       
       
         
           
             
               σ 
                
               
                   
               
                
               2 
             
             = 
             
               
                 ∑ 
                 
                   j 
                   = 
                   1 
                 
                 
                   N 
                    
                   
                       
                   
                    
                   φ 
                 
               
                
               
                 
                   ∑ 
                   
                     i 
                     = 
                     1 
                   
                   
                     N 
                      
                     
                         
                     
                      
                     θ 
                   
                 
                  
                 
                   
                     
                       ( 
                       
                         
                           
                             XPR 
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           θ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           
                             θ 
                             i 
                           
                         
                         + 
                         
                           E 
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                             
                             · 
                             E 
                           
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           
                             
                               2 
                               
                                 i 
                                 , 
                                 j 
                               
                               * 
                             
                             · 
                             P 
                           
                            
                           
                               
                           
                            
                           φ 
                            
                           
                               
                           
                            
                           i 
                         
                       
                       ) 
                     
                     · 
                     sin 
                   
                    
                   
                       
                   
                    
                   
                     
                       θ 
                       i 
                     
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   
                     θ 
                     · 
                     Δ 
                   
                    
                   
                       
                   
                    
                   φ 
                 
               
             
           
         
       
     
     where: R is related to the cross covariance between antennas  1  and  2 ; i, j are indices relating to the angular position of the measured sample; Nθ represents the number of θ angles; and, Nφ represents the number of φ angles. 
     Then, the envelope correlation, ρ e , is: 
     
       
         
           
             
               ρ 
               e 
             
             = 
             
               
                 
                    
                   
                     R 
                     12 
                   
                    
                 
                 2 
               
               
                 σ 
                  
                 
                     
                 
                  
                 
                   1 
                   · 
                   σ 
                 
                  
                 
                     
                 
                  
                 2 
               
             
           
         
       
     
     In these calculations, values for XPR (polarization ratio of incident field),), and) and the form of P θ  and P φ  functions are dependent on the RF environment (e.g., urban, suburban, rural, highway, etc.). 
     As an example, expressions for P θ  and P φ  for a channel model with uniform spread in azimuth and Gaussian spread in elevation is given below: 
     
       
         
           
             
               P 
                
               
                   
               
                
               θ 
                
               
                   
               
                
               i 
             
             = 
             
               
                 
                   P 
                   v 
                 
                  
                 i 
               
               = 
               
                 
                   A 
                   V 
                 
                 · 
                 
                   exp 
                   
                     - 
                     
                       [ 
                       
                         
                           
                             ( 
                             
                               
                                 θ 
                                  
                                 
                                     
                                 
                                  
                                 i 
                               
                               - 
                               
                                 m 
                                 v 
                               
                             
                             ) 
                           
                           2 
                         
                         
                           2 
                           · 
                           
                             σ 
                             v 
                             2 
                           
                         
                       
                       ] 
                     
                   
                 
               
             
           
         
       
       
         
           
             
               P 
                
               
                   
               
                
               φ 
                
               
                   
               
                
               i 
             
             = 
             
               
                 
                   P 
                   h 
                 
                  
                 i 
               
               = 
               
                 
                   A 
                   h 
                 
                 · 
                 
                   exp 
                   
                     - 
                     
                       [ 
                       
                         
                           
                             ( 
                             
                               
                                 θ 
                                  
                                 
                                     
                                 
                                  
                                 i 
                               
                               - 
                               
                                 m 
                                 h 
                               
                             
                             ) 
                           
                           2 
                         
                         
                           2 
                           · 
                           
                             σ 
                             h 
                             2 
                           
                         
                       
                       ] 
                     
                   
                 
               
             
           
         
       
     
     where: Av and Ah are normalization constants such that P θ  and P φ =1 when integrated over the sphere; m y , m h  are mean angle of arrival of the respective θ, φ polarized external fields, in one embodiment having typical values of m v =5 degrees and m h =10 degrees; and σ θ , σ φ are the angular spreads of the respective θ, φ polarized external fields, in one embodiment having typical values of σ θ =15 degrees and σ φ=30 degrees. 
     It should be noted, however, that other expressions are possible. 
     Several phone mockups with dual antennas were fabricated. Complex patterns were measured and the fading correlation was calculated from the patterns for each test case. The resultant ρ values ranged from 0.05 to 0.98. Additionally, the same mockup phones were used to measure the correlation between signals received by each antenna in typical indoor environments. The tests were performed in areas covered by the local PCS service provider. 
     In particular, referring to  FIG. 7 , the measured “pattern” correlation results from measurements in test chamber  20  were seen to compare favorably to those obtained from raw field measurements. For example, graph  700  includes a horizontal axis  702  corresponding to measured pattern ρ values and a vertical axis  704  corresponding to field ρ values for: a phone  706  having a single dipole antenna connected to a splitter and measured in non-line-of-sight (“NLOS”) conditions (indoors); a phone  708  having two pair of dipole antennas with 0.05λ separation measured on a rooftop in near line-of-sight (“LOS”) conditions; a phone  710  having two pair of dipole antennas with 0.05λ separation measured in NLOS conditions; a clamshell phone  712  having one external antenna and one internal antenna measured in NLOS conditions; a clamshell phone  714  having one external antenna and one internal antenna measured in NLOS conditions; a phone  716  with a dual stubby external antenna measured in NLOS conditions; and, a phone  718  with a stubby external antenna and an internal antenna measured in NLOS conditions. Thus, graph  700  indicates that the ρ&#39;s calculated from the patterns and field data nearly lay on top of each other for a large range of ρ values. 
     Due to the correlation between the measured pattern ρ&#39;s and the field ρ&#39;s, these results confirm that laboratory tests can be performed, according to the described embodiments, to evaluate the diversity performance of dual antenna diversity enabled wireless devices without having to resort to extensive field testing. 
     Further, referring to  FIG. 8 , a table  800  includes an example of calculated ρ&#39;s  802  for different channel models  804  using measured radiated patterns from a demonstration phone. In this case, channel models  804  include an indoor environment with an outside base transceiver station, an urban microcell, an urban macrocell, and a highway macrocell. Further, each channel model  804  includes a different set of variables  806 . In this case, for example, variables  806  include polarized wave, m, angular spread, σ, and polarization ratio, XPR. It should be noted that the statistics used for the channel models were from measurements done by Kalliola, et. al., “Angular Power Distribution and Mean Effective Gain of Mobile Antennas In Different Propagation Environments,”  IEEE Transactions on Vehicular Technology , Vol. 51, No. 5, September 2002, hereby incorporated by reference. Based on these calculated results, the described apparatus and methods provide a robust approach for using complex radiated patterns to estimate the fading correlation between dual antennas in mobile environments to characterize the diversity performance of diversity-enabled wireless devices. 
     Thus, in the described embodiments, one or more predetermined radiated performance characteristics may be determined for a wireless device during a single test, where the wireless device is uncabled, and where the wireless device records its own measured values along with synchronization data in a resident memory. For example, the radiated performance characteristics may include the TIS value, the TRP value, and the envelope correlation, ρ e . The calculated value of the radiated performance characteristic, based on measurements described herein, may then be compared to some predetermined threshold, such as may be set by a network carrier, a manufacture or standards group, in order to determine a radiated performance acceptability, approval, and/or certification of the wireless device. 
     While the foregoing disclosure shows illustrative embodiments, it should be noted that various changes and modifications could be made herein without departing from the scope of the described embodiments as defined by the appended claims. Furthermore, although elements of the described embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.