Patent Publication Number: US-10313838-B2

Title: Method and apparatus for assisted positioning in a wireless communication system

Description:
CROSS-REFERENCE 
     This application is a divisional of U.S. application Ser. No. 12/774,410, filed May 5, 2010, and entitled “METHOD AND APPARATUS FOR ASSISTED POSITIONING IN A WIRELESS COMMUNICATION SYSTEM,” said application claiming priority to U.S. Provisional Application No. 61/258,540, filed Nov. 5, 2009, and entitled “METHOD AND APPARATUS FOR RRC-SUPPORTED POSITIONING IN A WIRELESS COMMUNICATION SYSTEM,” and further claiming priority to U.S. Provisional Application No. 61/259,056, filed Nov. 6, 2009, and entitled “METHOD AND APPARATUS FOR RRC-SUPPORTED POSITIONING IN A WIRELESS COMMUNICATION SYSTEM,” the entirety of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     I. Field 
     The present disclosure relates generally to wireless communications, and more specifically to techniques for determining position of respective devices operating in a wireless communication system. 
     II. Background 
     Wireless communication systems are widely deployed to provide various communication services; for instance, voice, video, packet data, broadcast, and messaging services can be provided via such wireless communication systems. These systems can be multiple-access systems that are capable of supporting communication for multiple terminals by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems. 
     Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. In such a system, each terminal can communicate with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link can be established via a single-in-single-out (SISO), multiple-in-signal-out (MISO), or a multiple-in-multiple-out (MIMO) system. 
     Mobile devices and/or other devices operating in a wireless communication system can ascertain their present location by performing position fixing (also referred to herein as positioning, position estimation, etc.) in a variety of manners. For example, positioning reference signals (PRSs) and/or other suitable signals can be transmitted by various network cells within range of a mobile device, and upon receipt of such signals the mobile device can utilize time difference of arrival (TDOA) and/or other suitable techniques to estimate a current position. To aid in device positioning in a wireless communication system, to reduce the required complexity of positioning implementations employed within a wireless communication device, and/or to provide other suitable benefits, it would be desirable to implement techniques for assisting a device in conducting position fixing in a wireless communication environment. 
     SUMMARY 
     The following presents a simplified summary of various aspects of the claimed subject matter in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements nor delineate the scope of such aspects. Its sole purpose is to present some concepts of the disclosed aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     According to an aspect, a method is described herein. The method can comprise identifying a group of network cells; obtaining information relating to the group of network cells, the information comprising at least one of a bandwidth or a number of transmit antennas utilized by respective network cells in the group of network cells; and generating at least one positioning assistance message that includes at least a portion of the information. 
     A second aspect described herein relates to a wireless communications apparatus, which can comprise a memory that stores data relating to a group of network cells. The wireless communications apparatus can further comprise a processor configured to obtain information relating to the group of network cells, the information comprising at least one of a bandwidth or a number of transmit antennas utilized by respective network cells in the group of network cells, and to generate at least one positioning assistance message that includes at least a portion of the information. 
     A third aspect relates to an apparatus, which can comprise means for receiving network cell information that includes at least one of a bandwidth or a transmit antenna configuration utilized by a reference cell or a neighboring network cell that neighbors a serving network cell for one or more mobile users and means for generating positioning assistance messaging according to the network cell information. 
     A fourth aspect described herein relates to a computer program product, which can include a computer-readable medium that comprises code for causing a computer to receive network cell information that includes at least one of a bandwidth or a transmit antenna configuration utilized by a reference cell or a neighboring network cell that neighbors a serving network cell for one or more mobile users and code for causing a computer to generate positioning assistance messaging according to the network cell information. 
     According to a fifth aspect, a method is described herein that can comprise identifying a location server and a set of information relating to at least one of a utilized bandwidth or a number of employed transmit antennas and conveying at least a portion of the set of information relating to a utilized bandwidth or a number of employed transmit antennas to the location server to facilitate generation of positioning assistance messaging at the location server according to information conveyed to the location server. 
     A sixth aspect described herein relates to a wireless communications apparatus, which can comprise a memory that stores data relating to a location server and a set of information, wherein the set of information relates to at least one of a utilized bandwidth or a number of employed transmit antennas. The wireless communications apparatus can further comprise a processor configured to convey at least a portion of the set of information to the location server to facilitate generation of positioning assistance messaging at the location server according to information conveyed to the location server. 
     A seventh aspect relates to an apparatus, which can comprise means for identifying a set of information, wherein the set of information relates to at least one of an associated bandwidth or a deployed transmit antenna configuration and means for communicating at least a portion of the set of information to a location server in connection with generation of positioning assistance messaging. 
     An eighth aspect described herein relates to a computer program product, which can include a computer-readable medium that comprises code for causing a computer to identify a set of information, wherein the set of information relates to at least one of an associated bandwidth or a deployed transmit antenna configuration and code for causing a computer to communicate at least a portion of the set of information to a location server in connection with generation of positioning assistance messaging. 
     According to a ninth aspect, a method is described herein that can comprise receiving a positioning assistance message, the positioning assistance message comprising respective parameters relating to a reference base station and one or more indicator fields relating to at least one non-reference base station; setting respective parameters of the at least one non-reference base station noted by one or more indicator fields as substantially identical to corresponding parameters of the reference base station to the corresponding parameters of the reference base station; and receiving supplemental information relating to respective parameters of the at least one non-reference base station noted by one or more indicator fields as different from corresponding parameters of the reference base station. 
     A tenth aspect described herein relates to a wireless communications apparatus, which can comprise a memory that stores data relating to a reference base station and at least one non-reference base station. The wireless communications apparatus can further comprise a processor configured to receive a positioning assistance message that includes respective parameters relating to the reference base station and one or more indicator fields relating to the at least one non-reference base station, to set respective parameters of the at least one non-reference base station to corresponding parameters of the reference base station upon determining that the one or more indicator fields indicate that the respective parameters of the at least one non-reference base station are substantially identical to the corresponding parameters of the reference base station, and to receive supplemental information relating to respective parameters of the at least one non-reference base station upon determining that the one or more indicator fields indicate that the respective parameters of the at least one non-reference base station are different from corresponding parameters of the reference base station. 
     An eleventh aspect relates to an apparatus, which can comprise means for receiving positioning assistance messaging that includes respective reference cell parameters and respective flag fields relating to one or more non-reference cells; means for setting respective values of non-reference cell parameters indicated by one or more flag fields as equivalent to corresponding reference cell parameters to respective values of the corresponding reference cell parameters; and means for identifying supplemental information that includes respective values of non-reference cell parameters that are indicated by one or more flag fields as not equivalent to corresponding reference cell parameters. 
     A twelfth aspect described herein relates to a computer program product, which can include a computer-readable medium that comprises code for causing a computer to receive positioning assistance messaging that includes respective reference cell parameters and respective flag fields relating to one or more non-reference cells; code for causing a computer to set respective values of non-reference cell parameters indicated by one or more flag fields as equivalent to corresponding reference cell parameters to respective values of the corresponding reference cell parameters; and code for causing a computer to identify supplemental information that includes respective values of non-reference cell parameters that are indicated by one or more flag fields as not equivalent to corresponding reference cell parameters. 
     According to a thirteenth aspect, a method is described herein that can comprise identifying a reference cell and one or more neighbor cells; obtaining information relating to a positioning reference signal (PRS) bandwidth and an antenna port configuration utilized by the reference cell and the one or more neighbor cells; constructing a PRS information element for the reference cell that includes at least the PRS bandwidth utilized by the reference cell; obtaining information relating to PRS bandwidth and antenna port configurations utilized by the one or more neighbor cells to the reference cell; generating neighbor cell information elements for respective neighbor cells, wherein a neighbor cell information element for a corresponding neighbor cell includes an antenna port configuration utilized by the corresponding neighbor cell if the antenna port configuration utilized by the corresponding neighbor cell differs from the antenna port configuration utilized by the reference cell, a PRS information element for the corresponding neighbor cell if the PRS bandwidth utilized by the corresponding neighbor cell differs from the PRS bandwidth utilized by the reference cell, and respective flags indicating presence or absence of an antenna port configuration or a PRS information element in the neighbor cell information element; and constructing at least one positioning assistance message that includes the PRS information element for the reference cell and a list of respectively generated neighbor cell information elements. 
     To the accomplishment of the foregoing and related ends, one or more aspects of the claimed subject matter comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the claimed subject matter. These aspects are indicative, however, of but a few of the various ways in which the principles of the claimed subject matter can be employed. Further, the disclosed aspects are intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a system for conducting network-assisted positioning in a wireless communication system in accordance with various aspects. 
         FIG. 2  is a block diagram of a system for generating positioning assistance messaging for one or more mobile devices in accordance with various aspects. 
         FIG. 3  illustrates an example structure that can be utilized for a positioning assistance message in accordance with various aspects. 
         FIG. 4  is a block diagram of a system for obtaining and utilizing network cell information in connection with generating assistance messaging for positioning in accordance with various aspects. 
         FIG. 5  is a block diagram of a system that facilitates position fixing based on positioning assistance data in accordance with various aspects. 
         FIG. 6  is a block diagram of a system for low complexity mobile device positioning in a wireless communication system in accordance with various aspects. 
         FIGS. 7-10  are flow diagrams of respective methodologies for network-assisted positioning in a wireless communication system. 
         FIGS. 11-13  are block diagrams of respective apparatuses that facilitate low complexity position fixing in a wireless communication system. 
         FIGS. 14-15  are block diagrams of respective wireless communication devices that can be utilized to implement various aspects described herein. 
         FIG. 16  illustrates a wireless multiple-access communication system in accordance with various aspects set forth herein. 
         FIG. 17  is a block diagram illustrating an example wireless communication system in which various aspects described herein can function. 
     
    
    
     DETAILED DESCRIPTION 
     Various aspects of the claimed subject matter are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more aspects. 
     As used in this application, the terms “component,” “module,” “system,” and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, an integrated circuit, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal). 
     Furthermore, various aspects are described herein in connection with a wireless terminal and/or a base station. A wireless terminal can refer to a device providing voice and/or data connectivity to a user. A wireless terminal can be connected to a computing device such as a laptop computer or desktop computer, or it can be a self contained device such as a personal digital assistant (PDA). A wireless terminal can also be called a system, a subscriber unit, a subscriber station, mobile station, mobile, remote station, access point, remote terminal, access terminal, user terminal, user agent, user device, or user equipment (UE). A wireless terminal can be a subscriber station, wireless device, cellular telephone, PCS telephone, cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, or other processing device connected to a wireless modem. A base station (e.g., access point or Node B) can refer to a device in an access network that communicates over the air-interface, through one or more sectors, with wireless terminals. The base station can act as a router between the wireless terminal and the rest of the access network, which can include an Internet Protocol (IP) network, by converting received air-interface frames to IP packets. The base station also coordinates management of attributes for the air interface. 
     Moreover, various functions described herein can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc (BD), where disks usually reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
     Various techniques described herein can be used for various wireless communication systems, such as Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier FDMA (SC-FDMA) systems, and other such systems. The terms “system” and “network” are often used herein interchangeably. A CDMA system can implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband-CDMA (W-CDMA) and other variants of CDMA. Additionally, CDMA2000 covers the IS-2000, IS-95 and IS-856 standards. A TDMA system can implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system can implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release that uses E-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). Further, CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). 
     Various aspects will be presented in terms of systems that can include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems can include additional devices, components, modules, etc. and/or omit some or all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches can also be used. 
     Referring now to the drawings,  FIG. 1  illustrates a system  100  for conducting network-assisted positioning in a wireless communication system in accordance with various aspects described herein. As  FIG. 1  illustrates, system  100  can include one or more network cells (e.g., base stations, access points (APs), Node Bs or Evolved Node Bs (eNBs), etc.), such as a reference cell  120  and one or more neighboring cells  122 . In one example, reference cell  120  and/or neighboring cell(s)  122  or other non-reference cells can communicate with one or more user equipment units (UEs also referred to herein as access terminals (ATs), mobile terminals, etc.)  130 . Reference cell  120  and/or one or more of neighboring cell(s)  122  can be a serving network cell for UE  130  such that UE  130  can engage in one or more uplink (UL, also referred to as reverse link (RL)) communications with its serving cell(s) and the serving cell(s) can engage in one or more downlink (DL, also referred to as forward link (FL)) communications to UE  130 . However, it should be appreciated that reference cell  120 , as well as neighboring cell(s)  122 , can be either serving cells or non-serving cells for a given UE  130  at any given time. 
     In accordance with one aspect, UE  130  and/or other entities within system  100  can fix the position of UE  130  using various methods. For example, a triangulation method can be utilized, wherein timing measurements are made on reference signals (e.g., positioning reference signals (PRSs)) and/or other highly detectable pilot signals, etc., transmitted by reference cell  120  and/or neighboring cell(s)  122 . As used generally herein, a “neighboring cell” or “neighbor cell” is used to refer to a cell that neighbors a serving network cell for a given UE  130 . However, it should be appreciated that other suitable network cells, such as network cells that border a designated reference cell  120 , could additionally be utilized as described herein. As shown in system  100 , UE  130  can utilize a position fixing module  132  and/or other suitable means to perform position fixing within system  100 . In one example, UE  130  can utilize positioning assistance data, such as relative transmit time differences between different reference cells  120  and/or neighboring cells  122 , locations of the nearest reference cells  120  and/or neighboring cells  122 , time offsets between reference signals transmitted by respective network cells, or the like, to enable a position fix, reduce complexity of measurements, improve performance of UE  130 , and/or other suitable ends. For example, as the complexity of TDOA measurements can vary depending on the amount of assistance data available at UE  130 , it can be appreciated that position fixing module  132  can be implemented at UE  130  with reduced complexity in the presence of enhanced assistance data. 
     As further shown in  FIG. 1 , the above and/or other suitable assistance data can be obtained by UE  130  from a location server  110  associated with system  100 . In one example, location server  110  can be a Serving Mobile Location Center (SMLC), an Evolved SMLC (E-SMLC), a SUPL (Secure User Plane Location) Location Platform (SLP), and/or any other suitable entity that can provide UE  130  with information to aid in the performance of position fixing module  132 . Additionally or alternatively, UE  130  can obtain positioning assistance messaging and/or other similar data from a serving base station (e.g., reference cell  120  and/or another suitable network cell). 
     In one example, location server  110  can include a positioning assistance message generator  112 , which can coordinate positioning of respective UEs  130  by generating and communicating positioning assistance messages within system  100 . For example, location server  110  can be configured to identify a group of network cells, based on which positioning assistance message generator  112  can be utilized to generate positioning assistance messaging. A group of identified network cells can include, for example, a serving network cell for one or more network users (e.g., UE  130 ) and one or more neighbor network cells to the serving network cell, a reference cell  120 , and/or any other suitable cell(s). 
     In accordance with one aspect, location server  110  can be configured with data relating to the configuration of a given reference cell  120  and/or respective neighbor cell(s)  122 , and positioning assistance message generator  112  can be configured to assemble such data into positioning assistance messaging. As noted above, a reference cell or base station can be a serving base station for one or more given network users (e.g., such as UE  130 ) or a non-serving base station for the one or more network users. Further, location server  110  can be configured to repeat various operations, such as cell identification, cell information collection, and positioning assistance data generation for a plurality of reference cells  120  within a predefined or predetermined range of location server  110  (e.g., some or all cells in the area of location server  110 ). 
     In accordance with one aspect, positioning assistance message generator  112  can be utilized to generate positioning assistance data for a given UE  130  in various manners as described in further detail herein. Upon generation of such data, location server  110  can communicate the generated data to the corresponding UE(s)  130  via one or more positioning assistance messages. In one example, positioning assistance messages generated and communicated by location server  110  can be radio resource control (RRC) messages, messages generated and/or transmitted according to a LTE Positioning Protocol (LPP), and/or messages of any other suitable type. 
     In one example, positioning assistance messages can be transmitted in a direct manner from location server  110  to UE(s)  130  by, for example, identifying one or more UEs  130  or other network users associated with a reference cell  120  corresponding to the positioning assistance messages and transmitting the positioning assistance messages to the one or more UEs  130  or other network users. Alternatively, positioning assistance messages can be provided to respective UEs  130  in an indirect manner by identifying a network cell that serves one or more UEs  130  or other network users and transmitting the positioning assistance messages to the identified network cell, thereby facilitating forwarding of the positioning assistance messages from the network cell to its served UEs  130  and/or other network users. 
     In accordance with another aspect, location server  110  can obtain various elements of information from respective reference cells  120  and/or neighboring cells  122 , which can be incorporated into positioning assistance messaging generated by positioning assistance message generator  112  and communicated to respective UEs  130 . Information obtained by location server  110  from respective reference cells  120  and/or neighboring cells  122  in this manner can include, for example, bandwidth information, antenna configuration information, and/or other suitable information. The use of such information by location server  110  in generating and communicating positioning assistance data is illustrated in further detail by system  200  in  FIG. 2 . 
     In some wireless communication systems (e.g., LTE systems or the like), it can be appreciated that respective network entities can be flexibly configured such that bandwidths utilized by a reference cell  120  (e.g., PRS bandwidth, etc.) can differ from that utilized by respective neighboring cells  122 . Additionally or alternatively, it can be appreciated that antenna configurations utilized by a reference cell  120  and/or neighboring cell(s)  122  can differ in some cases (e.g., with respect to a number of employed transmit antennas or the like). For example, respective network cells in system  200  can utilize different numbers of transmit antennas, based on which the respective network cells can transmit different numbers of reference signals to respective users. Thus, it can be appreciated that if a user is not provided with knowledge of a number of transmit antennas (and corresponding reference signals) utilized by a given cell, the user will be required to assume only a single antenna and reference signal is utilized by the cell, thereby nullifying performance increases associated with utilizing multiple antennas. Conversely, by enabling a user to receive reference signals from multiple antennas at a given network cell, performance of the user with respect to cell search, TDOA estimation, and the like can be improved. 
     In accordance with one aspect, location server  110  can leverage information relating to bandwidth and antenna configurations of respective network cells in system  200  by utilizing a bandwidth analyzer  212  and an antenna configuration analyzer  214 , respectively. In one example, based on information collected and/or analyzed by bandwidth analyzer  212  and/or antenna configuration analyzer  214 , positioning assistance message generator  112  at location server  110  can generate at least one positioning assistance message that includes information relating to PRS bandwidth, antenna port configurations, or the like, as utilized by reference cell  120  and/or neighboring cell(s)  122 . For example, positioning assistance message generator  112  can leverage bandwidth analyzer  212  and/or antenna configuration analyzer  214  to embed information relating to PRS bandwidth and/or an antenna port configuration utilized by a reference cell  120  and/or neighboring cell(s)  122  into at least one positioning assistance message. 
     In another example, location server  110  can analyze differences between PRS bandwidth, antenna port configurations, or the like, utilized by respective network cells in system  200  and utilize flags and/or other indicators to denote commonalities between properties of respective cells without requiring transmission of the properties for each cell separately. 
     By way of example, bandwidth analyzer  212  can compare a PRS bandwidth utilized by reference cell  120  to a PRS bandwidth utilized by a neighboring cell  122 , based on which positioning assistance message generator  112  can embed an indicator field or flag field corresponding to said comparison within at least one generated positioning assistance message. Such an indicator can be, for example, a 1-bit value that indicates whether the PRS bandwidth utilized by the reference cell  120  is equivalent to or different from the PRS bandwidth utilized by the neighboring cell  122 . Thus, upon determining that the PRS bandwidth of the reference cell  120  is different from the PRS bandwidth of the neighboring cell  122 , the PRS bandwidth of the neighboring cell  122  can be included in the at least one positioning assistance message. Otherwise, upon determining that the PRS bandwidth of the reference cell  120  is equivalent to the PRS bandwidth of the neighboring cell  122 , the PRS bandwidth of the neighboring cell  122  can be omitted from the at least one positioning assistance message. In one example, positioning assistance message generator  112  can embed an indicator of the presence or absence of the PRS bandwidth for the neighboring cell  122  as determined above into at least one corresponding positioning assistance message. Accordingly, it can be appreciated that a location server  110  and/or other suitable entities in system  200  can reduce messaging load associated with positioning assistance data in the event that multiple cells in system  200  share common bandwidth properties. 
     Similarly, antenna configuration analyzer  214  can compare an antenna port configuration utilized by reference cell  120  to an antenna port configuration utilized by a neighboring cell  122 , based on which positioning assistance message generator  112  can embed an indicator of said comparison within at least one generated positioning assistance message. Such an indicator can be, for example, a 1-bit value that indicates whether the antenna port configuration utilized by the reference cell  120  is equivalent to or different from the antenna port configuration utilized by the neighboring cell  122 . Thus, upon determining that the antenna port configuration of the reference cell  120  is different from the antenna port configuration of the neighboring cell  122 , the antenna port configuration of the neighboring cell  122  can be included in the at least one positioning assistance message. Otherwise, upon determining that the antenna port configuration of the reference cell  120  is equivalent to the antenna port configuration of the neighboring cell  122 , the antenna port configuration of the neighboring cell  122  can be omitted from the at least one positioning assistance message. In one example, positioning assistance message generator  112  can embed an indicator of the presence or absence of the antenna port configuration for the neighboring cell  122  as determined above into at least one corresponding positioning assistance message. Accordingly, it can be appreciated that a location server  110  and/or other suitable entities in system  200  can reduce messaging load associated with positioning assistance data in the event that multiple cells in system  200  share common antenna configuration properties. 
     In view of at least the above, location server  110  can, in accordance with various aspects, generate and/or communicate RRC messages, LPP messages, or the like that carry neighbor cell information as part of positioning assistance data. Such messages can include, for example, fields that indicate the bandwidth and/or number of transmit antennas of a given network cell (e.g., in addition to the usual fields like transmit time differences, etc.). Additionally or alternatively, the message size for such messages can be reduced by utilizing single-bit indications or other such means to identify whether a given neighboring cell  122  has the same bandwidth (or number of transmit antennas) as a reference cell  120 . 
     In accordance with one aspect, Observed TDOA (OTDOA) assistance data can be provided by location server  110  in the form of respective messages, which in one example can be formatted as shown by diagram  300  in  FIG. 3 . It should be appreciated, however, that diagram  300  is provided by way of non-limiting example and that, unless explicitly stated otherwise, the hereto appended claims are not intended to be limited to any given implementation(s). 
     In one example as shown in diagram  300 , an OTDOA assistance message can be constructed using a reference cell information block (e.g., corresponding to a reference cell  120 ) and a list of neighbor cell information blocks (e.g., corresponding to respective neighboring cells  122 ). A further example of this structure is shown below in Table 1 based on an information element (IE) Downlink-OTDOA-Provide-Assistance-Data, which can be utilized by a location server to provide assistance data to enable UE-assisted downlink OTDOA. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Example OTDOA assistance data structure. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                   
                 Downlink-OTDOA-Provide-Assistance-Data ::= SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 otdoaReferenceCellInfo 
                 OTDOAReferenceCellInfo, 
               
               
                   
                 otdoaNeighbourCellInfo 
                 OTDOANeighbourCellInfoList, 
               
            
           
           
               
               
            
               
                   
                 ... 
               
            
           
           
               
               
            
               
                   
                 } 
               
               
                   
                   
               
            
           
         
       
     
     In accordance with one aspect, a reference cell information block can be utilized by a location server to provide reference cell information for OTDOA assistance data. Based on such information, slot number offsets, expected OTDOAs, and/or other suitable information relating to respective neighbor cells can be provided relative to the cell defined by the reference cell information block. As shown in diagram  300 , the reference cell information block can include a physical cell identity (ID) field that specifies the physical cell identity of the reference cell for the assistance data, a global ID field that specifies a globally unique identity of the reference cell (e.g., an E-UTRAN (Evolved UMTS (Universal Mobile Telecommunications System) Radio Access Network) Global Cell Identifier) ECGI or the like), and a PRS information field that specifies a PRS configuration for the reference cell. An example structure for the reference cell information block is shown below in Table 2. 
                     TABLE 2               Example reference cell information block structure.                                            OTDOAReferenceCellInfo ::= SEQUENCE {                             physCellId   INTEGER (0..503),                                 cellGlobalId   ECGI   OPTIONAL,           prsInfo   PRSInfo   OPTIONAL,                         ...                         }                        
Further, an example structure for the PRS information block is shown below in Table 3. As shown in Table 3 and diagram  300 , the PRS information block can include a PRS bandwidth field that specifies the bandwidth on which PRS is configured, a PRS configuration field that specifies a configuration (e.g., a configuration index) for PRS, and a DL frames field that specifies a number of consecutive DL subframes that are configured for PRS.
 
     
       
         
           
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 Example PRS information block structure. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 PRSInfo ::= SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 prsBandwidth 
                 TBD, 
               
               
                   
                 prsConfigurationIndex 
                 INTEGER (0..4095), 
               
               
                   
                 numDLframes 
                 ENUMERATED { 1sf, 2sf, 4sf, 6sf, ... }, 
               
            
           
           
               
               
            
               
                   
                 ... 
               
            
           
           
               
            
               
                 } 
               
               
                   
               
            
           
         
       
     
     In accordance with another aspect, a neighbor cell information block list can be utilized by a location server to provide neighbor cell information for OTDOA assistance data. In one example, the neighbor cell information block list can be generated as a sequence of neighbor cell IEs, which can be sorted according to best measurement geometry at the a priori location estimate of the target device (e.g., in the event that the target device is expected to provide measurements in increasing neighbor cell list order, to the extent that such information is available to the target device). 
     As shown in diagram  300 , a neighbor cell information block can include a physical cell ID, a global ID, and a PRS information block for the corresponding cell in a similar manner to the reference cell information block. Further, a neighbor cell information block can include a frequency identifier field (e.g., in the event that the neighbor cell is not on the target UE&#39;s serving frequency), a cyclic prefix (CP) length field that specifies the CP length of the neighbor cell&#39;s PRS, an antenna port configuration field that specifies a number of antenna ports that are utilized by the neighbor cell for transmission of cell-specific reference signals, a slot number offset field that specifies the slot number offset between the neighbor cell and the corresponding reference cell, and fields for the expected OTDOA between the neighbor cell and the corresponding reference cell and the uncertainty for the expected OTDOA. An example structure that can be utilized for the neighbor cell information block list, as well as for individual neighbor cell information blocks, is provided by Table 4 below. 
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Example neighbor cell information block list and 
               
               
                 neighbor cell information block structure. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 OTDOANeighbourCellInfoList ::= SEQUENCE (SIZE (1..64)) OF 
               
               
                 OTDOANeighbourCellInfoElement 
               
               
                 OTDOANeighbourCellInfoElement ::= SEQUENCE { 
               
            
           
           
               
               
               
            
               
                   
                 physCellId 
                 INTEGER (0..503), 
               
            
           
           
               
               
               
               
            
               
                   
                 cellGlobalId 
                 ECGI 
                 OPTIONAL, 
               
               
                   
                 earfcn 
                 ARFCN-ValueEUTRA 
                 OPTIONAL, 
               
            
           
           
               
               
               
            
               
                   
                 cpLength 
                 ENUMERATED { normal, extended, 
               
            
           
           
               
               
               
            
               
                   
                 ... } 
                 OPTIONAL, 
               
            
           
           
               
               
               
               
            
               
                   
                 prsInfo 
                 PRSInfo 
                 OPTIONAL, 
               
            
           
           
               
               
               
            
               
                   
                 antennaPortConfig 
                 ENUMERATED {1-or-2-ports, 
               
            
           
           
               
               
               
            
               
                   
                 4-ports, ... } 
                 OPTIONAL, 
               
            
           
           
               
               
               
               
            
               
                   
                 slotNumberOffset 
                 INTEGER(0..31) 
                 OPTIONAL, 
               
            
           
           
               
               
               
            
               
                   
                 expectedOTDOA 
                 TBD 
               
               
                   
                 expectedOTDOAUncertainty 
                 TBD 
               
            
           
           
               
               
            
               
                   
                 ... 
               
            
           
           
               
            
               
                 } 
               
               
                   
               
            
           
         
       
     
     As further shown in Table 4 by optional fields and in diagram  300  by dashed fields, respective fields in a given neighbor cell information block can be omitted under certain circumstances. For example, in the event that information corresponding to a neighbor cell is substantially similar to corresponding information for a reference cell (e.g., with respect to cyclic prefix length, PRS bandwidth, antenna port configuration, slot timing, etc.), such information can be omitted from the neighbor cell information block. In one example, flags and/or other indicators of the presence or absence of one or more fields in a neighbor cell information block can be provided within positioning assistance messaging provided to one or more mobile users. In such an example, flags for given fields relative to a neighboring cell can additionally serve as indicators relating to whether corresponding parameters of the neighboring cell match those of a reference cell. 
     Turning next to  FIG. 4 , a block diagram of a system  400  for obtaining and utilizing network cell information in connection with generating assistance messaging for positioning in accordance with various aspects is illustrated. As shown by system  400 , a location server  110  (e.g., a SMLC or E-SMLC, a SLP, etc.) can communicate with a reference cell  120  to facilitate generation and transmission of positioning assistance signaling to one or more users. In accordance with one aspect, location server  110  can obtain information from reference cell  120  via an information collector  412  or other means, which can be utilized by a positioning assistance message generator  112  (e.g., with or without the aid of a bandwidth analyzer  212  and/or an antenna configuration analyzer  214 ) to generate positioning assistance messages. 
     In one example, a reference cell  120  and/or other suitable network cell can obtain at least one positioning assistance message from a location server  110  and subsequently forward the at least one positioning assistance message to one or more served users. Additionally or alternatively, reference cell  120  can receive a prompt for cell information (e.g., a cell identity  422 , antenna configuration  424 , and/or bandwidth configuration  426  relating to reference cell  120 ; neighbor cell information  428  relating to neighboring cells to a serving network cell; etc.) from location server  110 , in response to which reference cell  120  can convey cell information to the location server  110 . In general, information provided by reference cell  120  in response to a prompt by location server  110  can include cell identifiers, position information, a utilized PRS bandwidth or antenna port configuration, information relating to one or more neighboring network cells, or the like. 
     Referring now to  FIG. 5 , a system  500  that facilitates position fixing based on positioning assistance data in accordance with various aspects is illustrated. As shown by system  500 , a UE  130  can perform position fixing within system  500  in order to estimate its current location at least in part by computing a time difference of arrival between respective reference signals (e.g., PRS) transmitted by respective network cells  520  (e.g., serving or non-serving reference cells, neighboring cells, etc.). Further, UE  130  can utilize positioning assistance message(s) transmitted by a location server  110  and/or another suitable entity within system  500  (e.g., a network cell  520 ) to facilitate improved, lower complexity positioning. As further shown in system  500 , a UE  130  can utilize an assistance message analyzer  512  to identify information contained within one or more positioning assistance messages, based on which a PRS analyzer  514  can be utilized in combination with, or independently of, a position fixing module  132  to determine the location of UE  130 . 
     In accordance with one aspect, assistance message analyzer  512  at UE  130  can identify an indicator field within a positioning assistance message that indicates whether a PRS bandwidth utilized by a reference base station (e.g., associated with network cells  520 ) matches a PRS bandwidth utilized by respective non-reference base stations. Additionally or alternatively, an indicator field within a positioning assistance message can indicate whether an antenna port configuration utilized by the reference base station matches an antenna port configuration utilized by respective non-reference base stations. Upon such analysis, UE  130  can be configured to receive supplemental information relating to PRS bandwidth and/or antenna port configurations utilized by non-reference base stations that are indicated as utilizing a different PRS bandwidth or antenna port configuration from the reference base station. In one example, indicator fields used in this manner can be 1-bit indicators and/or any other suitable indicator(s). Subsequently, based on at least one of a positioning assistance message or received supplemental information, position fixing module  132  can conduct position fixing for UE  130 . 
     Turning now to  FIG. 6 , a block diagram of a system  600  for low complexity mobile device positioning in a wireless communication system is illustrated. System  600  can include one or more mobile devices  610 , which can communicate with one or more serving base stations  620  on an uplink and/or downlink. Further, one or more neighboring base stations  630  that are not serving base stations for mobile device  610  can be present in system  600 . 
     In accordance with an aspect, mobile device  610  and/or other suitable entities in system  600  can fix the position of mobile device  610  using various techniques. For example, mobile device  610  can utilize a triangulation method based on timing measurements made (e.g., by a timing module  612 ) on reference signals or pilot signals transmitted by respective base stations  620 - 630 . Thus, for example, mobile device  610  can receive respective reference signals from serving base station  620  and/or neighboring base station(s)  630  and measure the time difference (e.g., the TDOA) between the respective base stations  620  and/or  630  via timing module  612 . Based on these timing measurements, a position determination module  614  can fix or determine the location of mobile device  610 . 
     As a specific example of the above, two base stations  620  and/or  630  can transmit reference signals to mobile device  610 , which can arrive at different times at mobile device  610 . Accordingly, mobile device  610  can search for these reference signals and, upon detecting the signals, determine their TDOA. Based on the measured TDOA (and knowledge of the locations of the base stations  620  and/or  630  from which the reference signals were received), position determination module  614  can determine a candidate region corresponding to a hyperbola on which mobile device  610  can be located. Subsequently, by performing multiple measurements and determinations in this manner (e.g., with different pairs of base stations  620  and/or  630 ), it can be appreciated that mobile device  610  can fix its location by identifying a point of intersection between the respective candidate hyperbolas. 
     It can be appreciated that, in order to perform positioning in the above manner and/or other suitable manners, mobile device  610  can require various assistance data from entities within system  600 . This assistance data can include information such as the location of the nearest neighboring base stations  630  and/or serving base station  620 , relative transmit time differences between different base stations  620  and/or  630 , cell IDs of respective base stations  620  and/or  630  (e.g., in the event that reference signals transmitted by a given base station are a function of a cell ID of the base station), or the like. Such information can be utilized by mobile device  610  to, for example, enable position fixing, reduce measurement complexity, and/or improve positioning performance. In an aspect, positioning assistance data can be obtained by mobile device  610  via broadcast messaging and/or other suitable messaging from serving base station  620  (e.g., via a position information indicator module  622  or the like). 
     In accordance with an aspect, the complexity of TDOA measurements performed by mobile device  610  can vary depending on the amount of assistance data made available to mobile device  610  by serving base station  620  and/or other entities in system  600 . Further, in some wireless communication environments (e.g., LTE, etc.), mobile device  610  can in some cases be required to obtain additional information in order to efficiently perform positioning. 
     As a first example, it in some cases could be desirable for mobile device  610  to obtain information relating to the number of transmit antennas at a given base station. In an aspect, the number of transmit antennas can in some cases differ between base stations, based on which a plurality of reference signals may be available to mobile device  610 . However, if mobile device  610  does not have information relating to the number of transmit antennas available at a given base station, mobile device  610  may search only for a single transmit antenna per base station. This can, in turn, cause mobile device  610  to miss various reference signals transmitted by respective cells and/or cause an adverse effect on the performance of positioning at mobile device  610  in other manners. Similarly, in a network implementation where bandwidth can vary on a per-cell basis, it can be appreciated that mobile device  610  can in some cases be required to obtain information relating to the bandwidth utilized by a given base station in order to successfully detect reference signals transmitted by the base station. 
     Accordingly, to facilitate enhanced, reduced complexity positioning at mobile device  610  in a network environment that can utilize variable bandwidths and/or transmit antennas in the above manner, position information indicator module  622  and/or other suitable means associated with serving base station  620  or system  600  in general can provide information relating to bandwidth and/or transmit antennas of respective base stations  620  and/or  630  with messages that carry neighbor cell information as part of positioning assistance data. 
     In one example, positioning assistance messages provided to mobile device  610  can include fields that indicate the bandwidth and/or number of transmit antennas of a given neighboring base station  630 . Additionally or alternatively, such messages can include information relating to base station location, transmit time differences between respective base stations (e.g., time offsets between reference signal transmissions of respective non-synchronized base stations), or the like. 
     In accordance with another aspect, the size of the above positioning assistance messages can be reduced by utilizing field(s) that indicate whether a given neighboring base station  630  has the same bandwidth and/or the same number of transmit antennas as serving base station  620  (or another suitable reference base station). Accordingly, upon a neighboring base station  630  having the same bandwidth and/or number of transmit antennas as serving base station  620  and/or another suitable base station, an abbreviated indicator field (e.g., respective 1-bit indicators for bandwidth and/or transmit antennas) can be transmitted to mobile device  610  in place of providing full information for each base station  620 - 630 . 
     Referring now to  FIGS. 7-10 , methodologies that can be performed in accordance with various aspects set forth herein are illustrated. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts can, in accordance with one or more aspects, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more aspects. 
     With reference to  FIG. 7 , illustrated is a methodology  700  for network-assisted positioning in a wireless communication system. It is to be appreciated that methodology  700  can be performed by, for example, a positioning coordinator (e.g., location server  110 ) and/or any other appropriate network entity. Methodology  700  begins at block  702 , wherein a group of network cells (e.g., a reference cell  120  and/or one or more neighboring cells  122 ) is identified. Next, at block  704 , information is obtained relating to respective network cells in the group of network cells identified at block  702 . Such information can include, for example, a bandwidth and/or a number of transmit antennas utilized by the respective network cells. Methodology  700  can then conclude at block  706 , wherein at least one positioning assistance message is generated (e.g., by a positioning assistance message generator  112 ) that includes at least a portion of the information generated at block  704 . 
     Turning now to  FIG. 8 , a flow diagram of another methodology  800  for network-assisted positioning in a wireless communication system is illustrated. Methodology  800  can be performed by a base station (e.g., reference cell  120 ) and/or any other appropriate network entity. Methodology  800  begins at block  802 , wherein a location server (e.g., location server  110 ) and a set of information relating to at least one of a bandwidth or a number of employed transmit antennas utilized by an entity performing methodology  800  is identified. Methodology  800  can then conclude at block  804 , wherein at least a portion of the set of information identified at block  802  is conveyed to the location server identified at block  802  in order to facilitate generation of positioning assistance messaging at the location server according to the conveyed information. 
       FIG. 9  illustrates a third methodology  900  for network-assisted positioning in a wireless communication system. Methodology  900  can be performed by, for example, a mobile device (e.g., UE  130 ) and/or any other suitable network entity. Methodology  900  begins at block  902 , wherein a positioning assistance message is received (e.g., from a location server  110 , and/or a network cell  520 ) that includes respective parameters relating to a reference base station and one or more indicator fields relating to at least one non-reference base station. Next, at block  904 , respective parameters of the at least one non-reference base station noted by one or more indicator fields (e.g., in the positioning assistance message received at block  902 ) as substantially identical to corresponding parameters of the reference base station are set to the corresponding parameters of the reference base station. Additionally or alternatively, at block  906 , supplemental information is received that relates to respective parameters of the at least one non-reference base station noted by one or more indicator fields (e.g., in the positioning assistance message received at block  902 ) as different from corresponding parameters of the reference base station. 
     Referring now to  FIG. 10 , a further methodology  1000  for network-assisted positioning in a wireless communication system is illustrated. Methodology  1000  can be performed by, for example, a location server (e.g., location server  110 ), a Node B (e.g., reference cell  120  and/or a neighboring cell  122 ), and/or any other appropriate network entity. Methodology  1000  begins at block  1002 , wherein a reference cell and one or more neighbor cells are identified. Next, at block  1004 , information is obtained that relates to a PRS bandwidth and an antenna port configuration utilized by the reference cell and the one or more neighbor cells. 
     Upon completing the acts described at block  1004 , methodology  1000  can proceed to block  1006 , wherein a PRS information element is constructed for the reference cell identified at block  1002  that includes at least the PRS bandwidth utilized by the reference cell as ascertained at block  1004 . Further, at block  1008 , neighbor cell information elements are generated for respective neighbor cells identified at block  1002 . As shown at block  1008 , a neighbor cell information element for a corresponding neighbor cell can includes an antenna port configuration utilized by the corresponding neighbor cell if the antenna port configuration utilized by the corresponding neighbor cell differs from the antenna port configuration utilized by the reference cell, a PRS information element for the corresponding neighbor cell if the PRS bandwidth utilized by the corresponding neighbor cell differs from the PRS bandwidth utilized by the reference cell, and respective flags indicating presence or absence of an antenna port configuration or a PRS information element in the neighbor cell information element. Methodology  1000  can then conclude at block  1010 , wherein at least one positioning assistance message is constructed that includes the PRS information element for the reference cell as constructed at block  1006  and a list of respectively generated neighbor cell information elements as described at block  1008  (e.g., in a format similar to that illustrated by diagram  300 ). 
     Referring next to  FIGS. 11-13 , illustrated are respective apparatuses  1100 - 1300  that can be utilized to implement various aspects described herein. It is to be appreciated that apparatuses  1100 - 1300  are represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). 
     Turning first to  FIG. 11 , an apparatus  1100  that facilitates low complexity position fixing in a wireless communication system is illustrated. Apparatus  1100  can be implemented by a location manager (e.g., location server  110 ) and/or any other suitable network entity and can include a module  1102  for receiving network cell information that includes at least one of a bandwidth or a transmit antenna configuration utilized by a reference cell or a neighboring network cell to a serving network cell for one or more mobile users and a module  1104  for generating positioning assistance messaging according to the network cell information. 
     Referring next to  FIG. 12 , a second apparatus  1200  that facilitates low complexity position fixing in a wireless communication system is illustrated. Apparatus  1200  can be implemented by a network cell (e.g., reference cell  120  or a neighboring cell  122 ) and/or any other suitable network entity and can include a module  1202  for identifying information relating to at least one of an associated bandwidth or a deployed transmit antenna configuration and a module  1204  for conveying at least a portion of identified information to a location server in connection with generation of positioning assistance messaging. 
       FIG. 13  illustrates a third apparatus  1300  that facilitates low complexity position fixing in a wireless communication system. Apparatus  1300  can be implemented by a UE (e.g., UE  130 ) and/or any other suitable network entity and can include a module  1302  for receiving positioning assistance messaging that includes respective reference cell parameters and respective flag fields relating to one or more non-reference cells, a module  1304  for setting respective values of non-reference cell parameters indicated by one or more flag fields as equivalent to corresponding reference cell parameters to respective values of the corresponding reference cell parameters, and a module  1306  for identifying supplemental information that includes respective values of non-reference cell parameters that are indicated by one or more flag fields as not equivalent to corresponding reference cell parameters. 
       FIG. 14  is a block diagram of a system  1400  that can be utilized to implement various aspects of the functionality described herein. In one example, system  1400  includes a base station or Node B  1402 . As illustrated, Node B  1402  can receive signal(s) from one or more UEs  1404  via one or more receive (Rx) antennas  1406  and transmit to the one or more UEs  1404  via one or more transmit (Tx) antennas  1408 . Additionally, Node B  1402  can comprise a receiver  1410  that receives information from receive antenna(s)  1406 . In one example, the receiver  1410  can be operatively associated with a demodulator (Demod)  1412  that demodulates received information. Demodulated symbols can then be analyzed by a processor  1414 . Processor  1414  can be coupled to memory  1416 , which can store information related to code clusters, access terminal assignments, lookup tables related thereto, unique scrambling sequences, and/or other suitable types of information. Additionally, Node B  1402  can employ processor  1414  to perform methodologies  800 ,  1000 , and/or other similar and appropriate methodologies. In one example, Node B  1402  can also include a modulator  1418  that can multiplex a signal for transmission by a transmitter  1420  through transmit antenna(s)  1408 . 
       FIG. 15  is a block diagram of another system  1500  that can be utilized to implement various aspects of the functionality described herein. In one example, system  1500  includes a mobile terminal  1502 . As illustrated, mobile terminal  1502  can receive signal(s) from one or more base stations  1504  and transmit to the one or more base stations  1504  via one or more antennas  1508 . Additionally, mobile terminal  1502  can comprise a receiver  1510  that receives information from antenna(s)  1508 . In one example, receiver  1510  can be operatively associated with a demodulator (Demod)  1512  that demodulates received information. Demodulated symbols can then be analyzed by a processor  1514 . Processor  1514  can be coupled to memory  1516 , which can store data and/or program codes related to mobile terminal  1502 . Additionally, mobile terminal  1502  can employ processor  1514  to perform methodologies  900  and/or other similar and appropriate methodologies. Mobile terminal  1502  can also include a modulator  1518  that can multiplex a signal for transmission by a transmitter  1520  through antenna(s)  1508 . 
     Referring now to  FIG. 16 , an illustration of a wireless multiple-access communication system is provided in accordance with various aspects. In one example, an access point  1600  (AP) includes multiple antenna groups. As illustrated in  FIG. 16 , one antenna group can include antennas  1604  and  1606 , another can include antennas  1608  and  1610 , and another can include antennas  1612  and  1614 . While only two antennas are shown in  FIG. 16  for each antenna group, it should be appreciated that more or fewer antennas may be utilized for each antenna group. In another example, an access terminal  1616  can be in communication with antennas  1612  and  1614 , where antennas  1612  and  1614  transmit information to access terminal  1616  over forward link  1620  and receive information from access terminal  1616  over reverse link  1618 . Additionally and/or alternatively, access terminal  1622  can be in communication with antennas  1606  and  1608 , where antennas  1606  and  1608  transmit information to access terminal  1622  over forward link  1626  and receive information from access terminal  1622  over reverse link  1624 . In a frequency division duplex system, communication links  1618 ,  1620 ,  1624  and  1626  can use different frequency for communication. For example, forward link  1620  may use a different frequency then that used by reverse link  1618 . 
     Each group of antennas and/or the area in which they are designed to communicate can be referred to as a sector of the access point. In accordance with one aspect, antenna groups can be designed to communicate to access terminals in a sector of areas covered by access point  1600 . In communication over forward links  1620  and  1626 , the transmitting antennas of access point  1600  can utilize beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals  1616  and  1622 . Also, an access point using beamforming to transmit to access terminals scattered randomly through its coverage causes less interference to access terminals in neighboring cells than an access point transmitting through a single antenna to all its access terminals. 
     An access point, e.g., access point  1600 , can be a fixed station used for communicating with terminals and can also be referred to as a base station, an eNB, an access network, and/or other suitable terminology. In addition, an access terminal, e.g., an access terminal  1616  or  1622 , can also be referred to as a mobile terminal, user equipment, a wireless communication device, a terminal, a wireless terminal, and/or other appropriate terminology. 
     Referring now to  FIG. 17 , a block diagram illustrating an example wireless communication system  1700  in which various aspects described herein can function is provided. In one example, system  1700  is a multiple-input multiple-output (MIMO) system that includes a transmitter system  1710  and a receiver system  1750 . It should be appreciated, however, that transmitter system  1710  and/or receiver system  1750  could also be applied to a multi-input single-output system wherein, for example, multiple transmit antennas (e.g., on a base station), can transmit one or more symbol streams to a single antenna device (e.g., a mobile station). Additionally, it should be appreciated that aspects of transmitter system  1710  and/or receiver system  1750  described herein could be utilized in connection with a single output to single input antenna system. 
     In accordance with one aspect, traffic data for a number of data streams are provided at transmitter system  1710  from a data source  1712  to a transmit (TX) data processor  1714 . In one example, each data stream can then be transmitted via a respective transmit antenna  1724 . Additionally, TX data processor  1714  can format, encode, and interleave traffic data for each data stream based on a particular coding scheme selected for each respective data stream in order to provide coded data. In one example, the coded data for each data stream can then be multiplexed with pilot data using OFDM techniques. The pilot data can be, for example, a known data pattern that is processed in a known manner. Further, the pilot data can be used at receiver system  1750  to estimate channel response. Back at transmitter system  1710 , the multiplexed pilot and coded data for each data stream can be modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for each respective data stream in order to provide modulation symbols. In one example, data rate, coding, and modulation for each data stream can be determined by instructions performed on and/or provided by processor  1730 . 
     Next, modulation symbols for all data streams can be provided to a TX processor  1720 , which can further process the modulation symbols (e.g., for OFDM). TX MIMO processor  1720  can then provides N T  modulation symbol streams to N T  transceivers  1722   a  through  1722   t . In one example, each transceiver  1722  can receive and process a respective symbol stream to provide one or more analog signals. Each transceiver  1722  can then further condition (e.g., amplify, filter, and upconvert) the analog signals to provide a modulated signal suitable for transmission over a MIMO channel. Accordingly, N T  modulated signals from transceivers  1722   a  through  1722   t  can then be transmitted from N T  antennas  1724   a  through  1724   t , respectively. 
     In accordance with another aspect, the transmitted modulated signals can be received at receiver system  1750  by N R  antennas  1752   a  through  1752   r . The received signal from each antenna  1752  can then be provided to respective transceivers  1754 . In one example, each transceiver  1754  can condition (e.g., filter, amplify, and downconvert) a respective received signal, digitize the conditioned signal to provide samples, and then processes the samples to provide a corresponding “received” symbol stream. An RX MIMO/data processor  1760  can then receive and process the N R  received symbol streams from N R  transceivers  1754  based on a particular receiver processing technique to provide N T  “detected” symbol streams. In one example, each detected symbol stream can include symbols that are estimates of the modulation symbols transmitted for the corresponding data stream. RX processor  1760  can then process each symbol stream at least in part by demodulating, deinterleaving, and decoding each detected symbol stream to recover traffic data for a corresponding data stream. Thus, the processing by RX processor  1760  can be complementary to that performed by TX MIMO processor  1720  and TX data processor  1716  at transmitter system  1710 . RX processor  1760  can additionally provide processed symbol streams to a data sink  1764 . 
     In accordance with one aspect, the channel response estimate generated by RX processor  1760  can be used to perform space/time processing at the receiver, adjust power levels, change modulation rates or schemes, and/or other appropriate actions. Additionally, RX processor  1760  can further estimate channel characteristics such as, for example, signal-to-noise-and-interference ratios (SNRs) of the detected symbol streams. RX processor  1760  can then provide estimated channel characteristics to a processor  1770 . In one example, RX processor  1760  and/or processor  1770  can further derive an estimate of the “operating” SNR for the system. Processor  1770  can then provide channel state information (CSI), which can comprise information regarding the communication link and/or the received data stream. This information can include, for example, the operating SNR. The CSI can then be processed by a TX data processor  1718 , modulated by a modulator  1780 , conditioned by transceivers  1754   a  through  1754   r , and transmitted back to transmitter system  1710 . In addition, a data source  1716  at receiver system  1750  can provide additional data to be processed by TX data processor  1718 . 
     Back at transmitter system  1710 , the modulated signals from receiver system  1750  can then be received by antennas  1724 , conditioned by transceivers  1722 , demodulated by a demodulator  1740 , and processed by a RX data processor  1742  to recover the CSI reported by receiver system  1750 . In one example, the reported CSI can then be provided to processor  1730  and used to determine data rates as well as coding and modulation schemes to be used for one or more data streams. The determined coding and modulation schemes can then be provided to transceivers  1722  for quantization and/or use in later transmissions to receiver system  1750 . Additionally and/or alternatively, the reported CSI can be used by processor  1730  to generate various controls for TX data processor  1714  and TX MIMO processor  1720 . In another example, CSI and/or other information processed by RX data processor  1742  can be provided to a data sink  1744 . 
     In one example, processor  1730  at transmitter system  1710  and processor  1770  at receiver system  1750  direct operation at their respective systems. Additionally, memory  1732  at transmitter system  1710  and memory  1772  at receiver system  1750  can provide storage for program codes and data used by processors  1730  and  1770 , respectively. Further, at receiver system  1750 , various processing techniques can be used to process the N R  received signals to detect the N T  transmitted symbol streams. These receiver processing techniques can include spatial and space-time receiver processing techniques, which can also be referred to as equalization techniques, and/or “successive nulling/equalization and interference cancellation” receiver processing techniques, which can also be referred to as “successive interference cancellation” or “successive cancellation” receiver processing techniques. 
     It is to be understood that the aspects described herein can be implemented by hardware, software, firmware, middleware, microcode, or any combination thereof. When the systems and/or methods are implemented in software, firmware, middleware or microcode, program code or code segments, they can be stored in a machine-readable medium, such as a storage component. A code segment can represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
     For a software implementation, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes can be stored in memory units and executed by processors. The memory unit can be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art. 
     What has been described above includes examples of one or more aspects. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further combinations and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. Furthermore, the term “or” as used in either the detailed description or the claims is meant to be a “non-exclusive or.”