Patent Description:
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power,. Examples of such multiple-access systems may include 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, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), etc., and can use one or more protocols, such as high-speed uplink packet access (HSUPA), single carrier HSUPA (SC-HSUPA), dual carrier HSUPA (DC-HSUPA), etc..

Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more access points (e.g., base stations, femtocells, picocells, relay nodes, and/or the like) via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from access points to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to access points. Further, communications between mobile devices and access points may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or access points with other access points) in peer-to-peer wireless network configurations. <CIT> discloses a method and apparatus to perform position determination in a wireless (e.g., cellular) communication network with repeaters. A signal received by a terminal is initially identified as being from a repeater. A position and a position uncertainty for the identified repeater are obtained (e.g., from a repeater database) and provided as the position estimate and position uncertainty for the terminal if (<NUM>) a more accurate position estimate for the terminal cannot be obtained, (<NUM>) the terminal is deemed to be in an indoor environment, or (<NUM>) the terminal is located sufficiently close to the identified repeater. ; If information for additional delays associated with the identified repeater is available, then the position estimate for the terminal may be derived based on a "compensated" time measurement for the identified repeater (i.e., with the additional delays removed) and time measurements for at least two other transmitters received by the terminal. <CIT> discloses a method and system that determines mobile station position information based upon base station identification and a repeater discriminant. A position location database includes base station identifications and repeater discriminant combinations, and unique position information associated with each combination. A repeater implements a discriminant to a transmitted signal in either the forward link, reverse link, or both. The position location database is accessed to determine mobile station position information based upon a base station identification and repeater discriminant. <CIT> describes method and apparatus for determining whether a received signal is transmitted via a repeater. A source signal to be conveyed via a particular repeater may include, or be modified to include, a variety of signal characteristics having a predictable relationship that remains relatively constant, which may be taken together as a signature of the repeater. The signature may reflect a composite of distinct signals. A database of repeater signature references may be developed, and an adequate match between characteristics of an unknown received signal and such signature references indicates that at least part of the unknown signal transmitted via a repeater. Useful signal characteristics for repeater signatures may include some representative of signal strength, and time of arrival information, among many other possibilities.

In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with facilitating utilizing different transmission parameters for positioning reference signals (PRS) of passive distributed elements, as compared to those for a related access point. For example, passive distributed elements can refrain from transmitting PRSs such that wireless devices can only measure PRSs from the access point. In this example, wireless devices can be signaled to measure PRSs only in determining positioning to mitigate additionally determining position from common reference signals (CRSs) of the access point transmitted by the passive distributed elements.

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 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 wireless device, 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 Evolved Node B (eNB) or other 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. 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. 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.

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-<NUM>, IS-<NUM> and IS-<NUM> 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 <NUM> (Wi-Fi), IEEE <NUM> (WiMAX), IEEE <NUM>, 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 <NUM>" (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 that they may not include all of the devices, components, modules etc. discussed in connection with the figures.

Referring now to the drawings, <FIG> illustrates an example system <NUM> that facilitates providing wireless network access to one or more devices using one or more passive distributed elements. System <NUM> includes an access point <NUM> that provides a wireless device <NUM> with access to a core network (not shown). For example, access point <NUM> can provide wireless network access to wireless device <NUM> directly and/or through one or more passive distributed elements <NUM> and/or <NUM>, which can be wired and/or wirelessly attached to access point <NUM>, for example. Access point <NUM> can be substantially any device that provides access to one or more network components, such as a macrocell access point, femtocell or picocell access point, eNB, mobile base station, relay node, a portion thereof, and/or the like. Wireless device <NUM> can be substantially any device that receives access to a wireless network, such as a mobile device, UE, modem (or other tethered device), a portion thereof, etc. Passive distributed elements <NUM> and <NUM> can be radio frequency (RF) repeaters, remote radio heads (RRH), a portion thereof, or substantially any device that remotely transmits signals from an access point.

According to an example, passive distributed elements <NUM> and <NUM>, as described, can transmit signals transmitted by access point <NUM> to improve hearability thereof. Thus, for example, where access point <NUM> transmits a PRS, CRS, etc., passive distributed elements <NUM> and <NUM> can transmit substantially the same PRS, CRS, etc. Where wireless device <NUM> is attempting to determine its position, PRS, CRS, etc. received from passive distributed elements <NUM> and <NUM> can cause incorrect position determining since wireless device <NUM> associates the received PRS, CRS, etc. with the location of access point <NUM>. Access point <NUM>, for example, can control transmissions at the passive distributed elements <NUM> and <NUM> such that access point <NUM> can cause passive distributed elements <NUM> and <NUM> to transmit different signals during different time periods. In this regard, for example, passive distributed elements <NUM> and <NUM> can transmit PRS, CRS, etc. differently from access point <NUM> to mitigate confusion at wireless device <NUM>.

In an example, passive distributed elements <NUM> and <NUM> refrain from transmitting PRSs to mitigate confusion in determining positioning. Passive distributed elements <NUM> and <NUM>, however, can still transmit CRSs for various purposes (e.g., to facilitate channel estimation, etc.). Wireless device <NUM>, in this example, can utilize CRSs in addition or alternatively to PRSs to determine positioning, which can lead to incorrect results as described previously. Thus, where passive distributed elements <NUM> and <NUM> are not to be used for positioning, access point <NUM> can provision an indicator to wireless device <NUM> to only measure PRSs to determine location. In this regard, wireless device <NUM> can ignore CRSs transmitted from passive distributed elements <NUM> and <NUM> (and access point <NUM>) when determining positioning. In this example, wireless device <NUM> measures only the PRS transmitted from access point <NUM> (and/or PRSs from other access points) to determine positioning.

Referring next to <FIG>, a communications apparatus <NUM> that can participate in a wireless communications network is illustrated. The communications apparatus <NUM> can be a wireless terminal, mobile device, a portion thereof, or substantially any device that can receive reference signals (RSs) in a wireless network. The communications apparatus <NUM> can include an assistance data receiving component <NUM> that obtains assistance data related to RSs transmitted in a wireless network, an RS receiving component <NUM> that can obtain one or more RSs from an access point and/or related passive distributed elements (not shown), and an RS utilizing component <NUM> that can process at least one of the one or more obtained RSs.

According to an example, assistance data receiving component <NUM> can obtain assistance data from an access point related to utilizing RSs transmitted by the access point and/or one or more related passive distributed elements. For example, assistance data receiving component <NUM> can obtain data related to location of the passive distributed elements, data related to identifying features of RSs transmitted by the passive distributed elements (e.g., resources utilized, RS sequences utilized, identifiers present in the RSs, etc.), indicators of types of RSs that can be utilized for performing computations at communications apparatus <NUM>, and/or the like. In addition, RS receiving component <NUM> can obtain RSs from the access point and/or the one or more passive distributed elements. RS utilizing component <NUM> can process and utilize the RSs according to the assistance data, for example.

In an example, where the assistance data includes indications specifying types of RSs that can be utilized for certain computations, RS utilizing component <NUM> can ignore other RSs. Thus, in an example, an access point can transmit PRSs without allowing passive distributed elements to transmit the same, as described above. Thus, the assistance data can specify to only measure PRSs for determining positioning. This can be a one bit indicator, in one example, where the other bit value indicates substantially any RS can be utilized for positioning. As described, when the assistance data indicates only measuring PRS for positioning, RS utilizing component <NUM> can ignore CRSs or other RSs received from the passive distributed elements and/or access point. Thus, in this example as well, positioning can be determined without confusion caused from passive distributed elements transmitting RSs related to the access point. When the assistance data indicates that substantially any RS can be utilized, on the other hand, RS utilizing component <NUM> can process substantially any RS from the related access point (and/or potential passive distributed elements) to determine positioning. In one example, however, this indicator can be specified where the access point does not leverage passive distributed elements.

Turning to <FIG>, illustrated is a wireless communications system <NUM> that facilitates processing RSs from access points that utilize passive distributed elements. System <NUM> includes an access point <NUM> that provides one or more wireless devices, such as wireless device <NUM>, with access to a core network (not shown). Moreover, access point <NUM> can be a macrocell access point, femtocell access point, picocell access point, mobile base station, a portion thereof, and/or substantially any device that provides wireless network access. In addition, for example, wireless device <NUM> can be a UE, modem (or other tethered device), a portion thereof, and/or substantially any device that receives access to a wireless network. In addition, access point <NUM> can utilize one or more passive distributed elements, such as passive distributed element <NUM> to increase signal power. Passive distributed element <NUM> can be an RF repeater, RRH, and/or the like, as described.

Access point <NUM> can comprise an assistance data providing component <NUM> that generates and transmits assistance data related to RSs of an access point and/or one or more passive distributed elements employed by the access point, a transmitting component <NUM> that transmits RSs and/or other data to a wireless device, and a remote transmitting component <NUM> that causes one or more passive distributed elements to transmit an RS or other data to a wireless device. Passive distributed element <NUM> can include a receiving component <NUM> that obtains signals from an access point <NUM> (e.g., dedicated or broadcast over a wired or wireless connection) and a transmitting component <NUM> that transmits the signals received from the access point <NUM>. Wireless device <NUM> comprises an assistance data receiving component <NUM> that obtains assistance data related to one or more access points and corresponding passive distributed elements, an RS receiving component <NUM> that obtains an RS from the one or more access points or corresponding passive distributed elements, and a position determining component <NUM> that computes a position of the wireless device <NUM> based at least in part on the received RS.

According to an example, access point <NUM> can transmit PRSs without causing passive distributed element <NUM> to transmit the same. Access point <NUM>, however, can cause passive distributed element <NUM> to transmit CRSs to allow devices receiving from passive distributed element <NUM> to communicate with the passive distributed element <NUM> (e.g., perform channel estimation for signals received therefrom, etc.). In this example, access point <NUM> can notify wireless device <NUM> to not consider CRSs in determining position (e.g., since the CRS received from passive distributed element <NUM> relates to access point <NUM>, and passive distributed element <NUM> is remotely located, as described). Thus, in this example, assistance data providing component <NUM> can transmit assistance data to wireless device <NUM> that indicates only PRSs are to be used in determining positioning. Assistance data receiving component <NUM> can obtain this indication for utilization in measuring PRSs for positioning.

In this regard, for example, transmitting component <NUM> can transmit a PRS related to access point <NUM>, and remote transmitting component <NUM> can refrain from forwarding the PRS to passive distributed element <NUM> for transmitting. RS receiving component <NUM> can obtain the PRS. Position determining component <NUM>, for example, can determine the PRS is, in fact, a PRS (and not a CRS or other RS) and can determine a position of the wireless device <NUM> based at least in part on the PRS. In addition, transmitting component <NUM> can transmit a CRS, and remote transmitting component <NUM> can cause passive distributed element <NUM> to transmit the CRS. Receiving component <NUM> can receive the CRS, and transmitting component <NUM> can transmit the CRS. RS receiving component <NUM> can receive the CRS from access point <NUM> and/or passive distributed element <NUM>. Position determining component <NUM>, however, can ignore the CRS for the purposes of determining position of the wireless device <NUM> based at least in part on the indicator in the assistance data, for example.

In another example, assistance data providing component <NUM> can set the indicator to a different value. For example, the indicator can be a <NUM>-bit indicator for which one value indicates to only utilize PRSs in determining position while the other value indicates not to only utilize PRSs in determining position. Thus, when assistance data providing component <NUM> communicates the indicator set to the latter value, RS receiving component <NUM> can obtain the PRS and CRS(s) described above, and position determining component <NUM> can discern a position of wireless device <NUM> based at least in part on the PRS and/or CRS(s). It is to be appreciated, in this example, that assistance data providing component <NUM> can additionally include location information related to access point <NUM> in the assistance data. Moreover, this indicator value can be utilized, for example, where passive distributed element <NUM> is not present such that all RSs in the cell are generated by access point <NUM> (and thus there is no confusion from passive distributed elements in determining location from RSs, as described).

Referring now to <FIG>, 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.

Referring to <FIG>, an example methodology <NUM> that facilitates determining signals that can be utilized for computing a position is illustrated. At <NUM>, an indicator can be received specifying one or more signal types receivable from one or more access points or passive distributed elements for determining a position. In an example, passive distributed elements can transmit CRSs related to corresponding access points. Thus, specifying not to use CRSs for positioning (and instead to use only PRSs) can mitigate any resulting confusion. Where an access point does not have passive distributed elements, however, it can indicate that substantially any RS can be utilized to determine positioning. As described, in an example, this can be a <NUM>-bit indicator in assistance data. In any case, at <NUM>, signals of the one or more signal types can be measured to determine positioning data.

Referring to <FIG>, an example methodology <NUM> that facilitates indicating one or more signal types that can be utilized to determine a position is illustrated. At <NUM>, an indication can be transmitted to one or more wireless devices related to one or more signal types receivable for computing positioning data. As described, the indication can be received in assistance data. The indication, for example, can be a <NUM>-bit indicator that specifies whether or not only PRSs should be used for determining a position. At <NUM>, a signal of the one or more signal types can be transmitted to the one or more wireless devices. Thus, the wireless devices can utilize at least the signal for determining a position (e.g., and other signals of the one or more types from other access points or passive distributed elements).

It will be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding determining resources for transmitting a PRS at an access point, generating symbol sequences for the same, and/or the like. As used herein, the term to "infer" or "inference" refers generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic-that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources.

Now referring to <FIG>, illustrated is a system <NUM> that facilitates determining one or more signal types to utilize for determining positioning. For example, system <NUM> can reside at least partially within a base station, mobile device, or another device that provides access to a wireless network. It is to be appreciated that system <NUM> is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor using instructions and/or data retrieved from a computer readable storage medium. System <NUM> includes a logical grouping <NUM> of electrical components that can act in conjunction. For instance, logical grouping <NUM> can include an electrical component for receiving an indicator specifying one or more signal types receivable from one or more access points or passive distributed elements for determining a position <NUM>.

As described, the indicator can specify whether or not to use only PRSs in determining a position, and thus can be a <NUM>-bit indicator in one example. For example, for access points that utilize passive distributed elements, specifying to only measure PRSs allows the passive distributed elements to not transmit PRSs but still transmit CRS and other RSs without allowing measuring thereof for determining positioning. Further, logical grouping <NUM> can comprise an electrical component for measuring signals of the one or more signal types to determine positioning data <NUM>. Additionally, system <NUM> can include a memory <NUM> that retains instructions and/or data for executing functions associated with electrical components <NUM> and <NUM>. While shown as being external to memory <NUM>, it is to be understood that one or more of electrical components <NUM> and <NUM> can exist within memory <NUM>.

Now referring to <FIG>, illustrated is a system <NUM> that facilitates indicating one or more signal types useable for determining a position. For example, system <NUM> can reside at least partially within a base station, mobile device, or another device that provides access to a wireless network. It is to be appreciated that system <NUM> is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor using instructions and/or data retrieved from a computer readable storage medium. System <NUM> includes a logical grouping <NUM> of electrical components that can act in conjunction. For instance, logical grouping <NUM> can include an electrical component for transmitting an indication to one or more wireless devices related to one or more signal types receivable for computing positioning data <NUM>.

As described, the indicator can specify whether or not to use only PRSs in determining a position, and thus can be a <NUM>-bit indicator in one example. For example, where system <NUM> utilizes passive distributed elements, specifying to only measure PRSs allows the passive distributed elements to not transmit PRSs but still transmit CRS and other RSs without allowing measuring thereof for determining positioning to mitigate confusion resulting from the remotely located passive distributed element transmitting RSs of system <NUM>. Further, logical grouping <NUM> can comprise an electrical component for transmitting a signal of the one or more signal types to the one or more wireless devices <NUM>. Additionally, system <NUM> can include a memory <NUM> that retains instructions and/or data for executing functions associated with electrical components <NUM> and <NUM>. While shown as being external to memory <NUM>, it is to be understood that one or more of electrical components <NUM> and <NUM> can exist within memory <NUM>.

<FIG> is a block diagram of a system <NUM> that can be utilized to implement various aspects of the functionality described herein. In one example, system <NUM> includes a base station or Node B <NUM>. As illustrated, Node B <NUM> can receive signal(s) from one or more UEs <NUM> via one or more receive (Rx) antennas <NUM> and transmit to the one or more UEs <NUM> via one or more transmit (Tx) antennas <NUM>. Additionally, Node B <NUM> can comprise a receiver <NUM> that receives information from receive antenna(s) <NUM>. In one example, the receiver <NUM> can be operatively associated with a demodulator (Demod) <NUM> that demodulates received information. Demodulated symbols can then be analyzed by a processor <NUM>. Processor <NUM> can be coupled to memory <NUM>, 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. In one example, Node B <NUM> can employ processor <NUM> to perform methodologies <NUM>, <NUM>, and/or other similar and appropriate methodologies. Node B <NUM> can also include a modulator <NUM> that can multiplex a signal for transmission by a transmitter <NUM> through transmit antenna(s) <NUM>.

<FIG> is a block diagram of another system <NUM> that can be utilized to implement various aspects of the functionality described herein. In one example, system <NUM> includes a mobile terminal <NUM>. As illustrated, mobile terminal <NUM> can receive signal(s) from one or more base stations <NUM> and transmit to the one or more base stations <NUM> via one or more antennas <NUM>. Additionally, mobile terminal <NUM> can comprise a receiver <NUM> that receives information from antenna(s) <NUM>. In one example, receiver <NUM> can be operatively associated with a demodulator (Demod) <NUM> that demodulates received information. Demodulated symbols can then be analyzed by a processor <NUM>. Processor <NUM> can be coupled to memory <NUM>, which can store data and/or program codes related to mobile terminal <NUM>. Additionally, mobile terminal <NUM> can employ processor <NUM> to perform methodologies <NUM>, <NUM>, and/or other similar and appropriate methodologies. Mobile terminal <NUM> can also employ one or more components described in previous figures to effectuate the described functionality; in one example, the components can be implemented by the processor <NUM>. Mobile terminal <NUM> can also include a modulator <NUM> that can multiplex a signal for transmission by a transmitter <NUM> through antenna(s) <NUM>.

Referring now to <FIG>, an illustration of a wireless multiple-access communication system is provided in accordance with various aspects. In one example, an access point <NUM> (AP) includes multiple antenna groups. As illustrated in <FIG>, one antenna group can include antennas <NUM> and <NUM>, another can include antennas <NUM> and <NUM>, and another can include antennas <NUM> and <NUM>. While only two antennas are shown in <FIG> 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 <NUM> can be in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to access terminal <NUM> over forward link <NUM> and receive information from access terminal <NUM> over reverse link <NUM>. Additionally and/or alternatively, access terminal <NUM> can be in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to access terminal <NUM> over forward link <NUM> and receive information from access terminal <NUM> over reverse link <NUM>. In a frequency division duplex system, communication links <NUM>, <NUM>, <NUM> and <NUM> can use different frequency for communication. For example, forward link <NUM> may use a different frequency then that used by reverse link <NUM>.

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 <NUM>. In communication over forward links <NUM> and <NUM>, the transmitting antennas of access point <NUM> can utilize beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals <NUM> and <NUM>. 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 <NUM>, can be a fixed station used for communicating with terminals and can also be referred to as a base station, a Node B, an access network, and/or other suitable terminology. In addition, an access terminal, e.g., an access terminal <NUM> or <NUM>, 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>, a block diagram illustrating an example wireless communication system <NUM> in which various aspects described herein can function is provided. In one example, system <NUM> is a multiple-input multiple-output (MIMO) system that includes a transmitter system <NUM> and a receiver system <NUM>. It should be appreciated, however, that transmitter system <NUM> and/or receiver system <NUM> 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 <NUM> and/or receiver system <NUM> 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 <NUM> from a data source <NUM> to a transmit (TX) data processor <NUM>. In one example, each data stream can then be transmitted via a respective transmit antenna <NUM>. Additionally, TX data processor <NUM> 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 <NUM> to estimate channel response. Back at transmitter system <NUM>, the multiplexed pilot and coded data for each data stream can be modulated (i.e., 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 <NUM>.

Next, modulation symbols for all data streams can be provided to a TX MIMO processor <NUM>, which can further process the modulation symbols (e.g., for OFDM). TX MIMO processor <NUM> can then provides NT modulation symbol streams to NT transceivers 1722a through 1722t. In one example, each transceiver <NUM> can receive and process a respective symbol stream to provide one or more analog signals. Each transceiver <NUM> can then further condition (e.g., amplify, filter, and up-convert) the analog signals to provide a modulated signal suitable for transmission over a MIMO channel. Accordingly, NT modulated signals from transceivers 1722a through 1722t can then be transmitted from NT antennas 1724a through 1724t, respectively.

In accordance with another aspect, the transmitted modulated signals can be received at receiver system <NUM> by NR antennas 1752a through 1752r. The received signal from each antenna <NUM> can then be provided to respective transceivers <NUM>. In one example, each transceiver <NUM> can condition (e.g., filter, amplify, and down-convert) 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 <NUM> can then receive and process the NR received symbol streams from NR transceivers <NUM> based on a particular receiver processing technique to provide NT "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 MIMO/data processor <NUM> 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 MIMO/data processor <NUM> can be complementary to that performed by TX MIMO processor <NUM> and TX data processor <NUM> at transmitter system <NUM>. RX MIMO/data processor <NUM> can additionally provide processed symbol streams to a data sink <NUM>.

In accordance with one aspect, the channel response estimate generated by RX MIMO/data processor <NUM> 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 MIMO/data processor <NUM> can further estimate channel characteristics such as, for example, signal-to-noise-and-interference ratios (SNRs) of the detected symbol streams. RX MIMO/data processor <NUM> can then provide estimated channel characteristics to a processor <NUM>. In one example, RX MIMO/data processor <NUM> and/or processor <NUM> can further derive an estimate of the "operating" SNR for the system. Processor <NUM> 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 <NUM>, modulated by a modulator <NUM>, conditioned by transceivers 1754a through 1754r, and transmitted back to transmitter system <NUM>. In addition, a data source <NUM> at receiver system <NUM> can provide additional data to be processed by TX data processor <NUM>.

Back at transmitter system <NUM>, the modulated signals from receiver system <NUM> can then be received by antennas <NUM>, conditioned by transceivers <NUM>, demodulated by a demodulator <NUM>, and processed by a RX data processor <NUM> to recover the CSI reported by receiver system <NUM>. In one example, the reported CSI can then be provided to processor <NUM> 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 <NUM> for quantization and/or use in later transmissions to receiver system <NUM>. Additionally and/or alternatively, the reported CSI can be used by processor <NUM> to generate various controls for TX data processor <NUM> and TX MIMO processor <NUM>. In another example, CSI and/or other information processed by RX data processor <NUM> can be provided to a data sink <NUM>.

In one example, processor <NUM> at transmitter system <NUM> and processor <NUM> at receiver system <NUM> direct operation at their respective systems. Additionally, memory <NUM> at transmitter system <NUM> and memory <NUM> at receiver system <NUM> can provide storage for program codes and data used by processors <NUM> and <NUM>, respectively. Further, at receiver system <NUM>, various processing techniques can be used to process the NR received signals to detect the NT 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..

Claim 1:
A method (<NUM>) of wireless communication performed by a wireless device (<NUM>; <NUM>), comprising:
receiving (<NUM>) an indicator that specifies whether only positioning reference signals, PRS, or any reference signal, RS receivable from one or more access points (<NUM>) that provide access to a core network and/or passive distributed elements (<NUM>, <NUM>) that remotely transmit signals from the one or more access points (<NUM>) can be utilized for determining a position of the wireless device (<NUM>; <NUM>);
receiving reference signals from an access point (<NUM>) and/or one or more passive distributed elements (<NUM>, <NUM>); and
determining (<NUM>) positioning data only based on PRS included in the received RS when the indicator specifies that only PRS can be utilized for determining a position, or determining positioning data based on any of the received RS when the indicator specifies that any RS can be utilized for determining a position.