PATENT DOCUMENT

Publication Number: US-8718567-B2
Application Number: US-73210810-A
Country: US
Kind Code: B2

Title: Methods for calibrating radio-frequency receivers using code division multiple access test equipment

Abstract:
Wireless test equipment may be used to perform over-the-air testing of user equipment. The user equipment may contain an antenna and a receiver. The wireless test equipment may contain a call box that performs network-level testing by sending and receiving protocol-compliant network messages. The call box may transmit a radio-frequency test signal at a predetermined power. The antenna in the user equipment may receive the radio-frequency test signal and may provide the received radio-frequency test signal to the input of the receiver. The call box may send a network message such as a code-division-multiple-access intercode handover command to the user equipment to direct the user equipment to measure the received radio-frequency test signal power at the input of the receiver. The measured power may be transmitted to the call box as part of a pilot measurement message indicator, using an intercode handover command, or using other network messages.

Claims:
What is claimed is: 
     
       1. A method for performing over-the-air testing of user equipment using a radio communications tester, comprising:
 wirelessly receiving a given code-division-multiple-access protocol-compliant cellular network message with the user equipment; and 
 in response to receiving the given code-division-multiple-access protocol-compliant cellular network message with the user equipment, responding to the code-divisional-multiple-access protocol-compliant cellular network message with a test-specific action that differs from a response in a normal user mode, wherein the response in the normal user mode is to change to use of a code-division-multiple-access communication code specified by the given code-division-multiple-access protocol-compliant cellular network message. 
 
     
     
       2. The method defined in  claim 1 , further comprising:
 transmitting a wireless radio-frequency test signal; 
 receiving the wireless radio-frequency test signal with an antenna and providing the received wireless radio-frequency test signal to the receiver input, wherein responding to the code-divisional-multiple-access protocol-compliant cellular network message with the test-specific action comprises:
 measuring the wireless radio-frequency test signal at the receiver input to produce a measured power value; and 
 wirelessly transmitting the measured power value in one of a plurality of fields in a code-division-multiple-access network message. 
 
 
     
     
       3. The method defined in  claim 2 , wherein wirelessly transmitting the measured power value in the one of the plurality of fields in the code-division-multiple-access network message comprises wirelessly transmitting a code in an intercode handover command that is mapped to the measured power value. 
     
     
       4. The method defined in  claim 2  wherein wirelessly transmitting the measured power value in the one of a plurality of fields in the code-division-multiple-access network message comprises wirelessly transmitting the measured power value in a pilot measurement message indicator. 
     
     
       5. The method defined in  claim 1 , wherein wirelessly receiving the given code-division-multiple-access protocol-compliant cellular network message with the user equipment comprises:
 receiving a code in an intercode handover command that directs the wireless electronic device to measure the wireless radio-frequency test signal at the receiver input to produce the measured power value. 
 
     
     
       6. A method for using test equipment to perform over-the-air testing of user equipment with the test equipment, wherein the user equipment has a receiver with a receiver input, comprising:
 with the test equipment, transmitting a wireless radio-frequency test signal of a predetermined power; 
 with the user equipment, receiving the transmitted radio-frequency test signal using an antenna and providing the received radio-frequency test signal from the antenna to the receiver input, wherein the received radio-frequency test signal has a received power at the receiver input; and 
 with the test equipment, transmitting a wireless protocol-compliant network message with the test equipment that directs the user equipment to measure the received power, wherein transmitting the wireless protocol-compliant network message comprises transmitting a code-division-multiple-access protocol-compliant network message, and wherein transmitting the code-division-multiple-access protocol-compliant network message comprises transmitting a code in an intercode handover command that directs the user equipment to measure the received power. 
 
     
     
       7. The method defined in  claim 6  further comprising:
 receiving the wireless protocol-compliant network message with the user equipment; and 
 measuring the received power in response to receiving the wireless protocol-compliant network message with the user equipment. 
 
     
     
       8. The method defined in  claim 7  wherein measuring the received power produces a measured value of the received power, the method further comprising:
 wirelessly transmitting the measured value of the received power from the user equipment to the test equipment. 
 
     
     
       9. The method defined in  claim 8  wherein transmitting the measured value comprises transmitting the measured value using at least one protocol-compliant network message. 
     
     
       10. The method defined in  claim 8  wherein transmitting the measured value comprises transmitting the measured value in a field of a pilot measurement message indicator. 
     
     
       11. The method defined in  claim 8  wherein transmitting the measured value comprises transmitting a code in an intercode handover command that is mapped to the measured value. 
     
     
       12. A method for performing over-the-air testing of user equipment using a code-division-multiple-access radio communications tester, comprising:
 with an antenna and a receiver having an input in the user equipment, receiving a wireless radio-frequency test signal and making a corresponding radio-frequency test signal power measurement to produce a measured power value that is indicative of how much power the received radio-frequency test signal has at the input; 
 transmitting an intercode handover command from the code-division-multiple-access radio communications tester to the user equipment that directs the user equipment to make the radio-frequency test signal power measurement; and 
 transmitting the measured power value to the code-division-multiple-access radio communications tester in at least one code-division-multiple-access network message. 
 
     
     
       13. The method defined in  claim 12  wherein transmitting the measured power comprises transmitting the measured power in a pilot measurement message indicator field. 
     
     
       14. The method defined in  claim 12  wherein transmitting the measured power comprises transmitting a code in an intercode handover command that is mapped to the measured power. 
     
     
       15. The method defined in  claim 14  further comprising transmitting a code in an intercode handover command from the code-division-multiple-access radio communications tester to the user equipment that directs the user equipment to make the radio-frequency test signal power measurement.

Description:
BACKGROUND 
     This relates to testing, and more particularly, to wireless testing of electronic devices. 
     Electronic devices such as cellular telephones and portable computers contain wireless communications circuitry. A typical device contains an antenna coupled to a radio-frequency transceiver and an associated processor. During data transmission operations, the processor supplies data to the radio-frequency transceiver. A radio-frequency transmitter in the transceiver transmits the data using the antenna. During data reception operations, a receiver in the radio-frequency transceiver receives radio-frequency signals through the antenna and passes these signals to the processor. 
     Wireless electronic devices such as these are generally tested during manufacturing. When a wireless electronic device is being tested, the device is typically referred to as a device under test (DUT). The radio-frequency performance of a device under test may be tested using wired and wireless connections. With a typical wired test, a test probe is connected to a connector on a printed circuit board in the device. The connector may, for example, be interposed in a transmission line path between the transceiver and the antenna. The probe may tap into the transmission line to perform test measurements. For example, the test probe may be used to make measurements on the amount of power received through the antenna. 
     Wired tests such as these may be helpful in determining whether a device is functioning properly, but may not be sufficient in many situations. For example, wired measurements that bypass the antenna are not able to test for proper antenna functionality. Wireless measurements at a connector do not provide a direct measurement of the amount of radio-frequency signal power that is actually received at the input to the receiver, because the connector for the wired tap point is upstream from the receiver. Moreover, use of a cable to form a wired connection between a tester and a device under test introduces a conductive element into the test environment. Because the cable can influence the distribution of radio-frequency signals in the vicinity of the device under test, accurate wireless measurements can be difficult in the presence of the cable. 
     Wireless testing avoids some of these shortcomings of wired radio-frequency tests. With wireless testing, test equipment exchanges wireless signals with the device under test. The type of testing that is performed depends on the type of tester that is used. Low level tests (i.e., physical layer tests) can be performed using relatively simple equipment such as power meters. A power meter may, for example, be used to measure how much radio-frequency power is being transmitted by a device under test. Higher level tests (e.g., network layer tests) can be performed using complex test equipment such as call boxes. High level tests may, for example, involve the transmission and reception of protocol-compliant wireless test messages. These high level tests may be used to evaluate how well a device under test performs typical network layer tasks. 
     Although a variety of test equipment is available for performing wireless tests, there are gaps in test coverage. For example, existing wireless test techniques are not able to measure how much power is actually received at the radio-frequency receiver in the device under test. 
     Power meter equipment and other external test equipment is not able to measure received power levels in the device under test, because wired probes can only connect to the device under test at connector locations that bypass antennas and that are located upstream from the receiver and because wired test probes tend to disturb the wireless environment of the device. 
     Call boxes and other test equipment that handles network layer testing is typically only able to exchange predetermined protocol-compliant network messages with the device under test. For example, call boxes that handle code division multiple access (CDMA) protocols are only able to handle CDMA network messages that are compliant with CDMA protocols. These protocols do not include network message formats for transmitting receiver power measurements. 
     It would therefore be desirable to provide improved ways in which to make measurements on the amount of radio-frequency signal power that is received by the receiver in an electronic device. 
     SUMMARY 
     Wireless test equipment may be used to perform over-the-air testing of user equipment. The user equipment may be, for example, a cellular telephone, media player, portable computer, or other equipment that contains wireless circuitry. The user equipment may contain an antenna and a receiver. To ensure that the user equipment is functioning properly, the antenna may be used to receive a test signal that has been transmitted from the wireless test equipment at a predetermined power. The received test signal may be provided to an input of the receiver. 
     The wireless test equipment may contain a call box that performs network-level testing by sending and receiving protocol-compliant network messages. During testing, the call box may transmit a network message such as a code-division-multiple-access intercode handover command to the user equipment that directs the user equipment to measure the received radio-frequency test signal power at the input of the receiver. 
     In response to receiving the command from the test equipment, the user equipment may measure the test signal power at the receiver input. The value of the measured power may be returned to the call box wirelessly using network messages. 
     For example, the measured power value may be transmitted to the call box as one of the fields in a pilot measurement message indicator. The measured power value may replace a field that would otherwise be contained in the pilot measurement message indicator. If desired, other network messages may be used to transmit the measured power value to the call box. For example, the measured power value may be wirelessly provided to the call box by encoding the measured power value in intercode handover commands that are sent from the user equipment to the call box. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of an illustrative system in which test equipment may be used to test how much signal power is received by the receiver in a device under test in accordance with an embodiment of the present invention. 
         FIG. 2  is a table illustrating an illustrative encoding scheme that may be used to send control commands and measured data between test equipment and user equipment in the form of protocol-compliant network messages in accordance with an embodiment of the present invention. 
         FIG. 3  is a flow chart of illustrative steps involved in testing and calibrating electronic devices using a wireless test system of the type shown in  FIG. 1  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications such as cellular telephone communications or other wireless communications. 
     Due to manufacturing variations, there is generally a device-to-device variation in wireless performance. For example, the antennas and transmission lines in some devices may be more efficient at receiving radio-frequency signals and in conveying those signals to receiver circuitry on the devices than the antennas and transmission lines in other devices. Testing and calibration operations may be performed during manufacturing to ensure that finished devices operate properly in the field. 
     A test system of the type that may be used to make wireless test measurements on electronic devices is shown in  FIG. 1 . As shown in  FIG. 1 , test system  10  may include test equipment  12 . Test equipment  12  may include one or more testers. The testers in test equipment  12  may include radio communications testers of the type that are sometimes referred to as call boxes or wideband radio communications testers. Test equipment  12  may, for example, include a call box such as the CMW500 Wideband Radio Communication Tester available from Rohde &amp; Schwarz. Testers of this type may perform radio-frequency signaling tests for a variety of different radio-frequency communications bands and channels. For example, this type of tester may be used in performing network emulation functions by sending and receiving protocol-compliant network messages (e.g., messages compliant with a wireless communications protocol such as the CDMA2000 standard). Wireless tests such as these are sometimes referred to as over-the-air tests and can be used in confirming whether user equipment meets or exceeds carrier and manufacturer specifications. Computers may be connected to the testers of test equipment  12  (e.g., to control data acquisition and data processing functions). 
     The testers in test equipment  12  may be used directly or via computer control. When operated directly, a user may control a tester by supplying commands directly to the tester using the user input interface of the tester. For example, a user may press buttons on the tester while viewing information that is displayed on a display in the tester. In computer controlled configurations, a computer (e.g., software running autonomously or semi-autonomously on the computer) may communicate with the tester (e.g., by sending and receiving data over a wired or wireless path between the computer and the tester). 
     Test equipment  12  may communicate with user equipment  14  over wireless paths such as path  16 . To reduce signal interference, user equipment  14  may be housed in a test chamber during wireless testing. An antenna in the test chamber may be coupled to test equipment  12  using a cable. 
     User equipment  14  may be an electronic device such as a computer, a tablet computer, a laptop computer, a media player, a handheld computing device, a cellular telephone, a gaming device, an electronic book, or any other suitable electronic device. In test environments of the type shown in  FIG. 1 , user equipment  14  is being tested, so user equipment  14  may sometimes be referred to as a device under test (DUT). 
     As shown in  FIG. 1 , user equipment  14  has one or more antennas such as antenna  18 . Antenna  18  may be coupled to a receiver such as receiver  22  and a transmitter such as transmitter  24  in radio-frequency transceiver  20 . Filter and matching circuitry may be provided in transmission line path  19  between antenna  18  and transceiver  20  (e.g., to route received and transmitted radio-frequency antenna signals by frequency, to perform impedance matching, etc.). 
     Storage and processing circuitry  26  may include nonvolatile and volatile memory and may include processing circuitry such as microprocessors, microcontrollers, digital signal processors, and application-specific integrated circuits. For example, storage and processing circuitry  26  may include one or more integrated circuits that implement the functions of baseband processor  28 . Processor  28  and other processing circuitry in storage and processing circuitry  26  may be used to generate data that is transmitted over antenna  18  using transmitter  24 . Processor  28  and other processing circuitry in storage and processing circuitry  26  may also be used to receive and process information that has been received from antenna  18  using receiver  22 . 
     During a typical data transmission operation, digital data is produced by storage and processing circuitry  26 . Transmitter  24  transits a radio-frequency antenna signal that includes this data. The radio-frequency antenna signal is conveyed to antenna  18  via transmission line path  19  and is wirelessly emitted by antenna  18 . During a typical data reception operation, radio-frequency antenna signals are sensed by antenna  18  and are conveyed to receiver  22  via transmission line path  19 . Receiver  22  conveys received radio-frequency antenna signal data to baseband processor  28  and other storage and processing circuitry  26  for digital processing. 
     Proper operation of user equipment  14  relies on accurate fabrication of the conductive structures that make up antenna  18  and the accurate fabrication of the transmission line structures and electrical components in antenna signal path  19  and receiver  22 . If, for example, the received radio-frequency antenna signal power Pin at input IN of receiver  22  is too high or too low, user equipment  14  may not operate satisfactorily. As an example, if the received radio-frequency antenna signals at input IN are too weak, receiver  22  may not be able to adequately receive these signals and the resulting data that is received by storage and processing circuitry  26  may contain undesirable errors. 
     During over-the-air testing with test equipment  12 , the input power Pin to receiver  22  can be measured. Received antenna signals are routed to receiver  22  via path  19  and the associated filter and matching components that are interposed within path  19 . In this type of test, user equipment  14  can be directed to use its resources (e.g., transceiver  20  and storage and processing circuitry  36 ) to measure the power Pin of the radio-frequency antenna signals that are being received by input IN of receiver  22  while a radio-frequency test signal of a predetermined power is emitted by test equipment  12 . 
     If desired, the measured power of these received signals (i.e., Pin), which is sometimes referred to as “receive power” or “received power,” can be used in calibrating user equipment  14  to compensate for manufacturing variations. Devices may be individually calibrated or may be calibrated in bulk, based on tests from a representative sample of devices. Once calibrated, low noise amplifiers or other input circuitry in equipment  14  can be automatically adjusted so that signals are properly received. Other actions may also be taken in response to receive power data. For example, user equipment  14  that is not receiving a sufficiently strong signal Pin at input IN of receiver  22  may be reworked on the factory line to improve performance or may be discarded. 
     Particularly in situations in which test equipment  12  includes protocol-compliant call boxes or other over-the-air test equipment that complies with wireless communications standards (e.g., the CDMA2000 standard), it may be challenging to wirelessly gather data on measured receive powers. This is because the wireless communications protocols that are implemented by such testers in test equipment  12  generally do not include provisions for performing this type of test or for uploading measured receive power data. 
     As an example, the CDMA2000 protocol provides for conventional over-the-air tests in which a call box directs a cellular telephone to make a measurement of the ratio of power in a CDMA pilot channel (Spilot) to the power in a traffic channel (Straffic). The measured ratio (Spilot/Straffic) is returned to the call box as one of the fields in a wireless pilot measurement message indicator (PMMI) network message. Conventional arrangements of this type are unable to measure Pin and return this information in an unobscured fashion to the call box. 
     System  10  of  FIG. 1  may overcome this issue by embedding the value of Pin in a network message. With one suitable arrangement, the value of Pin that is measured by user equipment  14  may be written into one of the fields in a CDMA2000 PMMI message. For example, the value of Pin may be inserted into the PMMI message in the field that would normally be used for the ratio of Spilot/Straffic. When the PMMI message is uploaded to test equipment  12 , the call box or other tester in test equipment  12  may extract the Pin data from the appropriate PMMI field. This information may then be processed manually (e.g., by a user examining the PMMI message on the display of a call box or computer) or automatically (e.g., by a processor in a call box or a computer that is collating and processing PMMI data and other test data that is gathered by the call box). 
     Information on Pin may also be uploaded from user equipment  14  to test equipment  12  by sending encoded intercode handover commands with particular (coded) values to the call box. Intercode handover commands are protocol-compliant network commands that are normally used to coordinate transitions between CDMA codes (i.e., chip codes). Consider, as an example, a cellular telephone that is communicating with a cellular base station during normal operation. Initially, the cellular telephone and base station may be communicating using a first code (e.g., code  0 ). During operation of the network, the base station may wish to use a different code for communicating with the cellular telephone. The base station may therefore send an intercode handover command to the cellular telephone that instructs the cellular telephone to change from using code  0  to using code  1 . After the change is complete, further cellular transmissions between the base station and cellular telephone may take place using the updated code (i.e., code  1 ). 
     During testing with system  10 , the presence of particular code values in the intercode handover commands can be exploited to implement a data encoding scheme. The data encoding scheme may be used by test equipment  12  to send control messages to user equipment  14 . For example, test equipment  12  may send an intercode handover command to user equipment  14  to direct user equipment  14  to measure Pin at the input of receiver  22 . The data encoding scheme may also be used by user equipment  14  to send data to test equipment  12 . For example, user equipment  14  may send an intercode handover command to test equipment  12  that informs test equipment  12  of the value of Pin that was measured by user equipment  14  in response to receiving the command to make this measurement from test equipment  12 . 
     Any suitable mapping between intercode handover command values and corresponding command and data values may be used in the encoding scheme. As just one example, user equipment  14  may interpret any intercode handover command from test equipment  12  that instructs user equipment  14  to change to code  0  as an instruction to measure Pin, as shown in the table of  FIG. 2 . When, in response, user equipment  14  measures that the value of Pin is equal to −105 dBm, user equipment  14  may send test equipment  12  a “code  6 ” intercode handover command. Different measured values of Pin can be conveyed to test equipment  12  using different corresponding intercode handover commands, as shown in the table of  FIG. 2 . For example, transmission of a “code  8 ” intercode handover command from user equipment  14  to test equipment  12  may indicate to test equipment  12  that user equipment  14  measured the value of Pin to be −107 dBm, etc. 
     Standard call boxes are able to send and receive network messages such as CDMA intercode handover commands in compliance with network standards (e.g., the CDMA2000 standard). Accordingly, the use of intercode handover commands or other protocol-compliant network messages to encode commands and data allows standard test equipment (i.e., standard protocol-compliant over-the-air test equipment such as protocol-compliant call boxes) to be used in test equipment  14 . The test environment for testing user equipment  14  therefore need not change dramatically from that used during regular over-the-air testing, enhancing compatibility with legacy test systems. 
     To ensure that user equipment  14  is able to properly respond during testing, baseband processor  28  or other circuitry in storage and processing circuitry  26  may be configured to recognize incoming commands from test equipment  12  that have been encoded using network messages. For example, storage and processing circuitry  26  may be provided with software code and/or hardware capabilities to recognize that a “code  0 ” intercode handover command or other particular network message should be interpreted as a command to measure Pin at input IN of receiver  22 . Storage and processing circuitry  26  of user equipment  14  may also be configured to return Pin values to test equipment  12  as a field in a CDMA protocol-compliant network message such as a PMMI message or other portion of a protocol-compliant network message or may be configured to use one or more intercode handover commands or other messages to convey the Pin value in encoded form (e.g., using an encoding scheme of the type described in connection with  FIG. 2 ). 
     Because storage and processing circuitry  26  and test equipment  12  in system  10  can convey commands and Pin data in protocol-compliant network messages, Pin measurements can be gathered during over-the-air testing, thereby allowing the performance of antenna  18  and path  19  to be evaluated. Cables may, if desired, be connected to user equipment  14  (e.g., to supply power and/or data) or, preferably, user equipment  14  may be powered from an internal battery while tests are performed without connecting cables to equipment  14 . 
     Illustrative steps involved in using system  10  of  FIG. 1  to make test measurements on user equipment  14  such as receive power measurements are shown in  FIG. 3 . 
     At step  30 , user equipment  14  (i.e., the device under test) may be placed into test mode. During test mode, test code may run on storage and processing circuitry  26  so that equipment  14  responds with test-specific actions. For example, in normal user mode, equipment  14  may respond to receipt of a “code  0 ” intercode handover command by changing to use of CDMA code  0  without further action, whereas in test mode receipt of this command may cause equipment  14  to take a Pin measurement. The test-specific functions that are implemented on user equipment  14  may be implemented using the test code and/or hardware features of storage and processing circuitry  26  and transceiver  20 . Test code may be stored in storage in storage and processing circuitry  26  and may be run using one or more processors in processing circuitry  26 . Test code may be provided as part of an operating system, as application code, as firmware, using combinations of these arrangements, etc. User equipment  14  may be placed in test mode by typing commands into equipment  14  using a user input interface in equipment  14 , by sending wireless messages to equipment  14 , by pressing a particular sequence of buttons on equipment  14 , by loading and launching a test program, by launching test features that are embedded in preloaded code, etc. 
     Once user equipment  14  is operating in test mode, test operations may proceed at step  32 . During the operations of step  32 , test equipment  12  may send a wireless over-the-air testing command to user equipment  14  that directs user equipment  14  to use receiver  22  or other circuitry in transceiver  20  or equipment  14  to measure Pin at the input of receiver  22  (e.g., actions other than the actions normally taken when operating equipment  14  in the field in a cellular telephone network). As described in connection with  FIG. 2 , the command that test equipment  12  sends to user equipment  14  may be provided in the form of a CDMA protocol-compliant network message such as an intercode handover command or other suitable network message. Test equipment  12  also transmits a reference radio-frequency test signal of a known power to user equipment  10 . 
     At step  34 , user equipment  14  receives the command from test equipment  12  that directs user equipment  14  to measure Pin or that directs user equipment  14  to take other desired actions (e.g., by measuring other desired operating parameters or performing other tasks that are different from the tasks that would be performed in response to the command during operation of equipment  14  in a cellular telephone network). In response to receiving the command, user equipment  14  may measure power Pin. Because this radio-frequency signal power is measured at input IN of receiver  22  and because the corresponding transmitted signal from test equipment  12  was made at a known power, the measured input power Pin is indicative of the characteristics of antenna  18  and can be used to test and, if desired, to calibrate antenna and transmission line performance (including any associated electrical components such as matching components and filters). Such measurements of antenna performance and transmission line performance are not possible using conventional test probes that bypass antenna  18  by tapping into path  19  with a wired probe. 
     At step  36 , user equipment  14  may transmit the measured value of the received radio-frequency signal power Pin to test equipment  12  using protocol-compliant network messages such as CDMA protocol-compliant network messages. The value of Pin may, for example, be transmitted to test equipment  12  as one of the fields in a PMMI message (e.g., in place of the field in the PMMI message that would otherwise be used to carry the Spilot/Straffic value). As described in connection with the table of  FIG. 2 , the value of Pin may also be conveyed by sending encoded intercode handover commands. The value of Pin may be embedded in the intercode handover commands or other such network messages using a coding scheme of the type shown in the table of  FIG. 2  or other suitable coding schemes. If desired, these coding schemes may involve adjustments to the number and type of protocol-compliant messages that are sent, the timing of the messages, or other suitable coding schemes. 
     At step  38 , test equipment  12  may receive and decode the information on Pin that was transmitted by user equipment  14 . Test equipment  12  may, for example, receive a network message such as a PMMI message and may extract Pin from one of the fields in the PMMI message. If Pin is sent in the form of an encoded intercode handover command, the value of Pin may be obtained by receiving and decoding the intercode handover command using a table such as the table of  FIG. 2 . Test results (i.e., values of Pin for one or more devices under test) may be used in calibrating the device under test or may be used to calibrate a larger number of devices. For example, test results from one or more devices under test may be used to determine appropriate nominal settings for low noise amplifiers and other circuits in a batch of devices. Calibration results or other associated settings may be stored in the storage and processing circuitry of each device during manufacturing. When operated normally in the field, each calibrated device may use these calibration settings to ensure proper operation within desired specifications. 
     Measurement of received power at a receiver in a wireless transceiver is merely one example of the type of action that may be taken using test system  10  of  FIG. 1 . In general, any suitable action that is different from the normal response to a network message may be taken in response to receipt of a network message during test mode operations. Examples of other actions that may be taken in response to receiving an encoded network message at the user equipment include measuring other radio-frequency powers, measuring power supply voltages, measuring other operating powers, adjusting device settings, changing test modes, etc. Because these actions can be programmed into user equipment  14 , a variety of test actions may be taken during over-the-air testing in addition to the normal actions that equipment  14  takes when responding to a particular received network message. By configuring the user equipment so that the user equipment responds differently during test mode than during normal operation, the user equipment can take desired actions during testing. For example, in response to receiving a given protocol-compliant cellular network message with the user equipment, action can be taken in the user equipment that differs from an appropriate protocol-compliant action to receipt of the given protocol-compliant cellular network message during normal operation of the user equipment in communications with a cellular telephone base station in a cellular telephone network. Similarly, any suitable data may be encoded during the process of transmitting network messages from user equipment  14  to test equipment  12  during test operations (e.g., other radio-frequency signal power values, voltage values can be encoded, the values of device settings can be encoded, etc.). Because data is uploaded from equipment  14  to device  12  differently than with existing network message schemes, more information can be conveyed with system  10  than when using conventional test arrangements and the use of overly complex test equipment is avoided. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20100325
Publication Date: 20140506
Grant Date: 20140506
Priority Date: 20100325
Inventors: VENKATARAMAN VISHWANATH
GREGG JUSTIN
EL-HASSAN WASSIM
Assignee: APPLE INC
CPC Classifications: [{"code": "H04B17/327", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B17/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B17/327", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B17/24", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 44657023