Patent Publication Number: US-2023133062-A1

Title: User Equipment Positioning in Long-Term Evolution Coordinated Multipoint Communication Systems

Description:
FIELD 
     Embodiments of the present disclosure generally relate to the field of wireless communication, and more particularly, to user equipment positioning in long-term evolution coordinated multipoint communication systems. 
     BACKGROUND 
     Coordinated multipoint (CoMP) systems are being studied as an enhanced multiple input multiple output (MIMO) technique to increase performance, especially at the cell edge, within the evolution of Long-Term Evolution Advanced (LTE-A) for Release 11 or beyond. However, there are some challenges for user equipment (UE) positioning within CoMP scenarios. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 
         FIG.  1    illustrates an example wireless communication network in accordance with various embodiments. 
         FIG.  2    is a diagram of a message flow in accordance with various embodiments. 
         FIG.  3    is an observed time difference of arrival (OTDOA) neighbor cell information element (IE) in accordance with various embodiments. 
         FIG.  4    is an OTDOA reference cell IE in accordance with various embodiments. 
         FIG.  5    is a block diagram of illustrative network components in accordance with various embodiments. 
         FIG.  6    is a block diagram of an example computing device that may be used to practice various embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. 
     Various operations may be described as multiple discrete actions or operations in turn, in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations may not be performed in the order of presentation. Operations described may be performed in a different order than the described embodiment. Various additional operations may be performed and/or described operations may be omitted in additional embodiments. 
     For the purposes of the present disclosure, the phrase “A and/or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C). The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having.” and the like, as used with respect to embodiments of the present disclosure, are synonymous. 
     As used herein, the term “circuitry” may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. 
     Embodiments of the present disclosure describe the use of virtual identifiers that are associated with remote radio heads (RRHs) to facilitate measuring and/or estimating a position of a user equipment (U E) in coordinated multipoint (CoMP) systems. 
       FIG.  1    schematically illustrates a communication network  100  in accordance with various embodiments. The communication network  100  (hereinafter “network  100 ”) may be a 3rd Generation Partnership Project (3GPP) long-term evolution (LTE) network (or an LTE-Advanced (LTE-A) network). The network  100  may include a radio access network (RAN)  104  such as an evolved universal terrestrial radio access network (E-UTRAN) that provides wireless communication access to user equipment (UE). The network  100  may further include a core network  108  such as an Evolved Packet Core (EPC) that performs various management and control functions of the network  100  and further provides a communication interface between the access networks and other networks, e.g., Internet  110 . 
     The RAN  104  may include various UEs, e.g., UE  112 . The UE  112  is shown generally as a cellular phone but may be a variety of different wireless communication devices employed by a user in various embodiments. The RAN  104  may further include a number of eNBs, e.g., eNB  116  and eNB  120 . The eNBs may coordinate and participate in various access functions of the RAN  104 . In particular, for example the eNBs may provide wireless communication to the UEs of the RAN  104 . 
     The eNB  120  may be part of a coordinated multipoint (CoMP) system  124  that further includes a plurality of RRHs, e.g., RRH  128 , RRH  132 , and RRH  136 . The RRHs may provide remote transmission/reception capabilities to the eNB  120 . The RRHs may be communicatively coupled with the eNB  120  through high-speed communication links, for example, fiber-optic links. 
     Components of the RAN  104 , for example, eNBs  116  and  120 , may be coupled with components of the core network  108  through an S1/S2 interface  140  or through some other appropriate communication interface. 
     The core network  108  may include, for example, a mobility management entity (MME) that provides control-plane signaling related to mobility and security for components of the RAN  104 . In various embodiments, the MME may be responsible for the tracking and paging of UEs within the RANs. The MME may be the termination point of the Non-Access Stratum (NAS). The MME may support an S1 interface with eNBs of the RAN  104  and an S11 interface with a serving gateway (S-GW)  148  of the core network  108 . While various specific interfaces are discussed herein, it will be understood that suitable variances may be made within the scope of the described embodiments. 
     The S-GW may provide user-plane signaling to transport IP data traffic between the UEs and external networks, e.g., the Internet. In  FIG.  1   , the MME and the S-GW may be combined in MME/S-GW  144 . 
     The S-GW may be logically connected with another gateway. e.g., packet data network gateway (P-GW)  148 . The P-GW  148  may also provide user-plane signaling and may serve as a point of interconnect between the core network  108  and other packet data networks (PDNs). 
     The core network  108  may further include a location-based services (LBS) server  152 . The LBS server  152  may be coupled with other components of the core network  108  such as, for example, MME/S-GW  144 , and may operate to determine locations of, and provide location-based services to, UEs disposed in the various RANs of network  100 . The location-based services may include services such as, but not limited to, emergency services, advertising/marketing services, mapping services, etc. In some embodiments, the LBS server  152  may provide UEs of various RANs with information regarding positioning reference signal (PRS) configurations of assistance data reference and neighbor cells. This may facilitate the positioning measurements conducted by the UEs. 
     While certain of the components of the core network  108  are shown together, for example, the MME/S-GW  144 , and others are shown separately, for example, the P-GW  148 , it is to be understood that various modifications may be made within the scope of the embodiments of the present disclosure. For example, the MME and the S-GW may be disposed in separate devices, the P-GW and the S-GW may be disposed in one device, etc. 
     As discussed above, CoMP systems may improve various performance metrics of network communication; however, in the realm of positioning measurements, present CoMP systems may inject ambiguity. This may be due to current positioning measurement operations being based on parameters that are identified by a cell ID of reference cell and neighbor cells. A UE performing positioning measurements based on PRSs transmitted from RRHs having a common cell ID may distort positioning measurements such as observed time difference of arrival (OTDOA), enhanced cell ID (ECID), etc. Therefore, embodiments of the present disclosure introduce the use of virtual identifiers that are associated with the various RRHs to improve the accuracy and reliability of positioning measurements performed by UEs served by, or neighbors to, CoMP-system cells. 
       FIG.  2    is a diagram  200  of a message flow between various components of the network  100  described above with respect to  FIG.  1   . The LBS server  152  may provide neighbor cell information, for example, information about eNB  116 , to the UE  112  in a neighbor cell IE, for example, an OTDOA-NeighborCellInfoListIE.  FIG.  3    illustrates an OTDOA-NeighborCellInfoListIE  300  in accordance with some embodiments. The OTDOA-NeighborCellInfoListIE  300  may include a list of positioning parameters of a number of neighbor cells. In some embodiments, the list may be arranged in a decreasing order of priority for measurement to be performed by a target device, with the first cell in the list being the highest priority for measurement. Other embodiments may include other list sortings. The target device may provide the available measurements in an order that corresponds to the sorting of the list within the OTDOA-NeighborCellInfoListIE  300 . 
     The OTDOA-NeighborCellInfoListIE  300  may include a virtual RRH identifier, virtualRRHID, that corresponds to each RRH in the list of neighbor cells. The virtualRRHID may be an integer value that uniquely identifies an RRH from other RRHs associated with a common eNB. The virtualRRHID may be used to encode and decode a PRS transmitted by a corresponding RRH. The OTDOA-NeighborCellInfoListIE  300  may further include other positioning parameters such as, but not limited to, a cell identifier of the neighbor cell, PRS-info (for example, antenna port configuration, slot number offset. PRS subframe offset, etc.). 
     The LBS server  152  may provide assistance data reference cell information, for example, information about a cell provided by eNB  120 , to the UE  112  in an OTDOA-ReferenceCellInfoIE.  FIG.  4    illustrates an OTDOA-ReferenceCellInfoIE  400  in accordance with some embodiments. The OTDOA-ReferenceCellInfoIE  400  may include a list of positioning parameters of a reference cell, which may or may not be a serving cell of the UE. Similar to the OTDOA-NeighborCellInfoListIE  300 , OTDOA-ReferenceCellInfoIE  400  may include one or more virtualRRHIDs that respectively correspond to RRHs of the reference cell, for example, a cell provided by CoMP system  124 . 
     The OTDOA-NeighborCellInfoList and OTDOA-ReferenceCellInfoIEs may be disposed in an LTE positioning protocol (LPP) message generated by the LBS server  152 . The LBS server  152  may transmit the LPP message to the UE  112 . In some embodiments, generation and/or transmission of the LPP message may be performed by upper layers such as an LPP layer within the LBS server  152 . 
     In some embodiments, the LBS server  152  may provide the LPP message to the MME/S-GW  144 , which may package the LPP message as a NAS message and deliver it to the eNB  120 . Upon receipt, the eNB  120  may package the LPP message as a radio resource control (RRC) message and deliver it to the UE  112 . 
     In various embodiments, the LBS server  152  may also transmit LPP messages to the eNBs of the reference and neighbor cells to enable subsequent generation and transmission of PRSs from the various transmission points of the RAN  104 . 
     Upon receiving the LPP message, the UE  112  may configure positioning measurement circuitry with the positioning parameters of the LPP message. Thereafter, the UE  112  may be capable of processing PRSs received from various transmission points of the RAN  104 . For example, the UE  112  may receive a PRS from a neighboring eNB, for example, eNB  116 , and from RRHs  128  and  132 . Upon receiving the PRSs, the UE may perform positioning measurements, for example, reference signal time difference (RSTD), based on the PRSs, with the resulting positioning measurement data (e.g., RSTD data) reported, in a measurement report, to an enhanced serving mobile location center (ESMLC) In the eNB  120 , for example. The ESMLC may use these RSTDs, and knowledge of the locations of the transmission points (e.g., the RRHs and eNBs) within the RAN  104 , to estimate a location of the UE  112 . 
     In some embodiments, the IE  112  may perform at least preliminary location estimates based on the positioning measurements and transmit the estimates in the measurement report. 
       FIG.  5    illustrates various components of the network  100  in further detail in accordance with some embodiments of the present disclosure. For example, the UE  112  is shown with configuration circuitry  504  coupled with positioning measurement circuitry  508 . Both the configuration circuitry  504  and the positioning measurement circuitry  508  may be coupled with a wireless transceiver  512  that is configured to facilitate over the air communication via one or more antennas  516 . 
     The RRH  128  may include control circuitry  520  coupled with a wireless transceiver  524  and further coupled with a remote radio transceiver  528 . The wireless transceiver  524  may be configured to facilitate over the air communication with the UE  112  via one or more antennas  532  of the RRH  128 . The remote radio transceiver  528  may be configured to communicate with the eNB  120  over a high-speed communication link, for example, a fiber-optic link. The control circuitry  520  may be responsible for various transmission/reception operations. In some embodiments, the control circuitry  520  may generate and transmit PRSs to UEs of the RAN  104 . 
     The eNB  120  may include control circuitry  536  coupled with a remote radio transceiver  540  and a communication transceiver  544 . The remote radio transceiver  540  may be configured to facilitate communication with the RRH  128  over the high-speed communication link. Similarly, the communication transceiver  544  may be configured to facilitate communication with one or more elements of the core network  108  such as, for example, LBS server  152 . The control circuitry  536  may control various communication aspects of the RAN  104  including, for example, operation of the RRHs of the CoMP system  124 . In some embodiments, the control circuitry  536  may include an ESMLC that may be used for various positioning services such as, but not limited to, forwarding the LPP message to the UE  112 , receiving the measurement report, and estimating a location of the UE  112 . 
     The LBS server  152  may include control circuitry  548  that may be configured to perform various LPP-layer operations. The control circuitry  548  may be coupled with a communication transceiver  552  and may be configured to perform various positioning and location-based services. 
     The communication links, shown generally as block bidirectional arrows in  FIG.  5   , may be direct or indirect communication links. For example, the high-speed communication link coupling the RRH  128  with the eNB  120  may be a direct communication link; while the communication link coupling the eNB  120  with the LBS server  152  may be an indirect communication link that includes, for example, MME/S-GW  144 . 
     Referring also to  FIG.  2   , the control circuitry  548  may determine a virtual identifier associated with RRH  128 . This determination may be as a result of the virtual identifier being generated locally by the LBS server  152  and assigned to the RRH or, alternatively, the LBS server  152  may be provided with an indication of the virtual identifier from another component in the network  100 . The control circuitry  548  may then generate an LPP message that includes, among other positioning parameters, an indication of the virtual identifier. The control circuitry  548  may then transmit the LPP message via the communication transceiver  552  to the UE  112 . 
     The eNB  120  may receive the LPP message from the LBS server  152  via the communication transceiver  544 . The control circuitry  536  may then configure various RRHs controlled by the eNB  120  with appropriate positioning parameters such as, but not limited to, virtual RRH IDs. With respect to RRH  128 , the eNB  120  may transmit the LPP message to the RRH  128  via the remote radio transceiver  540 . 
     The LPP message may also be transmitted to the UE  11 . 2  by the RRH  128 , the eNB  120 , or another RRH. 
     In some embodiments, the control circuitry  536  may configure PRS bandwidth, for example the number of resource blocks used for transmission of a PRS signal, and the period at which a PRS is transmitted. 
     The control circuitry  520  of the RRH  128  may receive the LPP message from the eNB  120  via the remote radio transceiver  528 . The control circuitry  520  may store the positioning parameters, including the virtual RRH ID, for later generation of PRSs. 
     The control circuitry  520  may include a pseudo-random sequence generator (PRSG)  556  and a reference signal generator (RSG)  560 . The PRSG  556  may be initialized with an initialization sequence based on the virtual identifier of the RRH  128  to generate a pseudo-random sequence. In some embodiments, the initialization sequence may be defined by: 
         c   init =2 10 *(7*( n   s +1)+ l+ 1)*(2* N   ID   cellCoMP +1)+2* N   ID   cellCoMP   +N   CP ,  Eq. 1
 
     where n s  is a number of a slot within a radio frame, l is an orthogonal frequency division multiplexing (OFDM) symbol number within the slot, N ID   cellCoMP  is a function of a cell identifier, N ID   cell , and the first virtual identifier, N ID   virtualRRHID , and 
     
       
         
           
             
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     In some embodiments, the pseudo-random sequence may be defined by a link-31 Gold sequence. The output sequence c(n) of length M PN , where n=0, 1, . . . , M PN -1, is defined by: 
         c ( n )=( x   1 ( n+N   c )+ x   2 ( n+N   c ))mod 2  x   1 ( n+ 31)=( x   1 ( n+ 3)+ x   1 ( n ))mod 2  x   2 ( n+ 31)=( x   2 ( n+ 3)+ x   2 ( n+ 2)+ x   2 ( n+ 1)+ x   2 ( n ))mod 2  Eq.2
 
     where N c =1600 and the first m-sequence may be initialized with x 1 (0)=1, x 1 (n)=0, n=1, 2, . . . , 30. Initialization of the second m-sequence may be denoted by c init =Σ l=0   30 x 2 (l)·2l with the value depending on the application of the sequence. 
     The pseudo-random sequence c(n) generated by the PRSG  556  may be provided to the RSG  560 , which may generate a PRS based on the pseudo-random sequence. In some embodiments, the PRS may be defined in the physical layer by: 
     
       
         
           
             
               
                 
                   
                     
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     The control circuitry  520  may transmit the PRS via the wireless transceiver  524  according to the PRS bandwidth and periodicity configurations provided by the eNB  120 . In some embodiments, the PRS may be transmitted on antenna port  6  using a configurable number of consecutive subframes. 
     In some embodiments, some or all of the functions of the control circuitry  520  may be employed in control circuitry  536 . In such embodiments, the RRH  128  may be used primarily for operations provided by wireless transceiver  524  and antennas  532 . 
     The configuration circuitry  504  of the UE  112  may receive the LPP message from the eNB  120 , for example. The configuration circuitry  504  may configure the positioning parameters based on the LPP message. 
     The positioning measurement circuitry  508  may observe the PRS sent from the RRH  128  (and other transmission points in the RAN  104 ). Observation of the PRS sent from the RRH  128  may be facilitated by prior configuration of the positioning parameters including the virtual RRH ID. This may allow the positioning measurement circuitry  508  to uniquely identify a PRS as coming from RRH  128  as opposed to coming from RRH  132 , for example. The positioning measurement circuitry  508  may perform measurements based on the observed PRSs. In various embodiments, the measurements may include, but are not limited to, OTDOA measurements such as RSTD. 
     The positioning measurement circuitry  508  may then generate a measurement report and transmit the measurement report to an eNB of a serving cell, for example, eNB  120 . 
     As discussed above, in some embodiments, the positioning measurement circuitry  508  may simply perform measurements based on the PRSs with the measurement results being fed back to the eNB. At that point, the eNB may estimate a location of the UE. In other embodiments, the positioning measurement circuitry  508  may perform at least preliminary estimations of the UE location. 
     Transmitting PRSs from RRHs based on virtual identities of the RRHs may facilitate positioning operations in a number of ways. For example, a UE with knowledge of the virtual IDs of the RRHs may be capable of identifying the individual PRSs with less interference from other PRSs. Further, the measurement results may be associated with a higher degree of accuracy given that a larger number of distinct PRSs may be used in the calculations. 
     A UE, RRH, eNB, and/or LBS server as described herein may be implemented into a system using any suitable hardware and/or software to configure as desired.  FIG.  6    illustrates, for one embodiment, an example system  600  comprising interface circuitry  602  (which may include radio frequency (RF) circuitry  604  and baseband circuitry  608  in some embodiments), application circuitry  612 , memory/storage  616 , display  620 , camera  624 , sensor  628 , and input/output (I/O) interface  632 , coupled with each other at least as shown. 
     The application circuitry  612  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with memory/storage  616  and configured to execute instructions stored in the memory/storage  616  to enable various applications and/or operating systems running on the system  600 . 
     Interface circuitry  602  may include circuitry such as, but not limited to, one or more single-core or multi-core processors designed to provide suitable communication interfaces for respective device and networking applications. While the interface circuitry  602  is shown in  FIG.  6    with baseband and RF circuitry, these components may not be included in a device that does not participate directly in wireless transmission/reception. 
     The baseband circuitry  608  may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include a baseband processor. The baseband circuitry  608  may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuitry  608  may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry  608  may support communication with an E-UTRAN and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), or a wireless personal area network (WPAN). Embodiments in which the baseband circuitry  608  is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry. 
     In various embodiments, baseband circuitry  608  may include circuitry to operate with signals that are not strictly considered as being in a baseband frequency. For example, in some embodiments, baseband circuitry  608  may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency. 
     RF circuitry  604  may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry  604  may include switches, filters, amplifiers, etc., to facilitate the communication with the wireless network. 
     In various embodiments, RF circuitry  604  may include circuitry to operate with signals that are not strictly considered as being in a radio frequency. For example, in some embodiments, RF circuitry  604  may include circuitry to operate with signals having an intermediate frequency, which is between a baseband frequency and a radio frequency. 
     In some embodiments, some or all of the constituent components of the baseband circuitry  608 , the application circuitry  612 , and/or the memory/storage  616  may be implemented together on a system on a chip (SOC). 
     In an embodiment in which the system  600  represents an eNB, for example, eNB  120 , the remote radio transceiver  540 , the communication transceiver  544 , and the control circuitry  536  may be implemented in the interface circuitry  602  and/or application circuitry  612 . 
     In an embodiment in which the system  600  represents a UE, for example, UE  112 , the configuration circuitry  504 , positioning measurement circuitry  508 , and/or wireless transceiver  512  may be implemented in the RF circuitry  604 , the baseband circuitry  608 , and/or the application circuitry  612 . 
     In an embodiment in which the system  600  represents an RRH, for example, RRH  128 , the control circuitry  520 , the wireless transceiver  524 , and the remote radio transceiver  528  may be implemented in the interface circuitry  602  and/or the application circuitry  612 . 
     In an embodiment in which the system  600  represents an LBS server, for example, LBS server  152 , the control circuitry  548  and the communication transceiver  522  may be implemented in the application circuitry  612  and/or the interface circuitry  602 . 
     Memory/storage  616  may be used to load and store data and/or instructions, for example, for system  600 . Memory/storage  616  for one embodiment may include any combination of suitable volatile memory (e.g., dynamic random access memory (DRAM)) and/or non-volatile memory (e.g., Flash memory). 
     In various embodiments, the I/O interface  632  may include one or more user interfaces designed to enable user interaction with the system  600  and/or peripheral component interfaces designed to enable peripheral component interaction with the system  600 . User interfaces may include, but are not limited to, a physical keyboard or keypad, a touchpad, a speaker, a microphone, etc. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power supply interface. In various embodiments, sensor  628  may include one or more sensing devices to determine environmental conditions and/or location information related to the system  600 . In some embodiments, the sensors may include, but are not limited to, a gyro sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of, or interact with, the baseband circuitry  608  and/or RF circuitry  604  to communicate with components of a positioning network, e.g., a global positioning system (GPS) satellite. 
     In various embodiments, the display  620  may include a display (e.g., a liquid crystal display, a touch screen display, etc.). 
     In various embodiments, the system  600  may be a mobile computing device such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smartphone, etc. In various embodiments, system  600  may have more or less components, and/or different architectures. 
     The following paragraphs describe examples of various embodiments. 
     Example 1 includes a location-based services (LBS) server comprising: a transceiver; and control circuitry coupled with the transceiver, the control circuitry to: determine a virtual identifier associated with a remote radio head (RRH) of a coordinated multipoint (CoMP) system that includes the RRH and an eNB; generate a long-term evolution (LTE) positioning protocol (LPP) message that includes an indication of the virtual identifier; and transmit, through the transceiver, the LPP message to a user equipment (UE). 
     Example 2 Includes the LBS server of Example 1, wherein the LPP message is to include observed time difference of arrival (OTDOA) assistance data and is to indicate a positioning reference signal (PRS) configuration for the RRH. 
     Example 3 includes the LBS server of Example 1, wherein the UE is to be served by the CoMP system at a time of transmission of the LPP message and the indication of the virtual identifier is to be included in an observed time difference of arrival (OTDOA) reference cell information IE. 
     Example 4 includes the LBS server of Example 1, wherein the UE is not to be served by the CoMP system at a time of transmission of the LPP message and the indication of the virtual identifier is to be included in an observed time difference of arrival (OTDOA) neighbor cell information list IE. 
     Example 5 Includes the LBS server of Example 1, wherein the transceiver is to receive a message from the eNB, and the control circuitry is to determine the virtual identifier based on the message. 
     Example 6 includes the LBS server of any of Examples 1-5, wherein the control circuitry is to determine a plurality of virtual identifiers that are respectively associated with a plurality of RRHs of the CoMP system and to generate the LPP message to include indications of the plurality of virtual identifiers. 
     Example 7 includes the LBS server of Example 6, wherein the plurality of RRHs are associated with a common physical cell identity. 
     Example 8 includes remote radio head (RRH) circuitry of a coordinated multipoint (CoMP) system, the RRH circuitry comprising: a wireless transceiver to facilitate communications with one or more user equipments (UEs); and control circuitry coupled with the wireless transceiver, the control circuitry to: transmit, via the wireless transceiver, a positioning reference signal (PRS) that is based on a virtual identifier associated with the RRH. 
     Example 9 includes the RRH circuitry of Example 8, wherein the control circuitry is to periodically transmit the PRS. 
     Example 10 Includes the RR H circuitry of Example 8 or 9, wherein the control circuitry comprises: a pseudo-random sequence generator to be initialized with a first initialization sequence based on the virtual identifier to generate a first pseudo-random sequence; and a reference signal generator to generate the PRS based on the first pseudo-random sequence. 
     Example 11 includes the RRH circuitry of Example 9, wherein the first initialization sequence is defined by: c init =2 10 *(7*(n s +1)+l+1)*( 2 *N ID   cellCoMP +1)+2*N ID   cellCoMP +N CP , where n s  is a number of a slot within a radio frame, l is an orthogonal frequency division multiplexing (OFDM) symbol number within the slot N ID   cellCoMP  is a function of a cell identifier, N ID   cell , and the first virtual identifier, N ID   virtualRRHID , and 
     
       
         
           
             
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     Example 12 includes the RRH circuitry of claim  11 , wherein the PRS is defined by: 
     
       
         
           
             
               
                 
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     Example 13 includes user equipment (UE) circuitry comprising: configuration circuitry to receive a long-term evolution (LTE) positioning protocol (LPP) message that includes an indication of a virtual identifier of a remote radio head (RRH); and positioning measurement circuitry coupled with the configuration circuitry, the positioning measurement circuitry to: receive a positioning reference signal (PRS) from the RRH; process the PRS based on the virtual identifier; and generate positioning measurement and estimation data based on the processed PRS. 
     Example 14 includes the UE circuitry of Example 13, wherein the positioning measurement data includes reference signal time difference (RSTD) data and the positioning measurement circuitry is further to: generate a measurement report that includes the RSTD data; and send the measurement report to a serving eNB. 
     Example 15 includes the UE circuitry of Example 13, wherein the configuration circuitry is further to receive indications of virtual identifiers of a plurality of RRHs. 
     Example 16 includes the UE circuitry of Example 13, wherein the configuration circuitry is to receive the indication of the virtual identifier in an observed time difference of arrival (OTDOA) reference cell information IE or in an OTDOA neighbor cell information list IE. 
     Example 17 includes the UE circuitry ofany of Examples 13-16, wherein the positioning measurement circuitry is to generate an estimate of a location of the UE based on the PRS. 
     Example 18 includes a coordinated multipoint (CoMP) system comprising: a plurality of remote radio heads (RRHs); and an eNB to facilitate radio access network (RAN) communications through the plurality of RRHs, the eNB to include control circuitry coupled with a remote-radio transceiver to: control a first RRH of the plurality of RRHs to transmit a first positioning reference signal (PRS) based on a first virtual identifier associated with the first RRH; and control a second RRH of the plurality of RRHs to generate a second PRS based on a second virtual identifier associated with the second RRH, wherein the first virtual identifier differs from the second virtual identifier. 
     Example 19 includes the CoMP system of claim  18 , wherein the first RRH includes: a pseudo-random sequence generator to be initialized with a first initialization sequence based on the first virtual identifier to generate a first pseudo-random sequence; and a reference signal generator to generate the first PRS based on the first pseudo-random sequence. 
     Example 20 includes the CoMP system of claim  19 , wherein the second RRH includes: a pseudo-random sequence generator to be initialized with a second initialization sequence based on the second virtual identifier to generate a second pseudo-random sequence; and a reference signal generator to generate the second PRS based on the second pseudo-random sequence. 
     Example 21 includes the CoMP system of Example 19, wherein the first initialization sequence is defined by: c init =2 10 *(7*(n s +1)+l+1)*( 2 *N ID   cellCoMP +1)+2*N ID   cellCoMP +N CP , where n s  is a number of a slot within a radio frame, l is an orthogonal frequency division multiplexing (OFDM) symbol within the slot, N ID   cellCoMP  is a function of a cell identifier, N ID   cell , and the first virtual identifier, N ID   virtualRRHID , and 
     
       
         
           
             
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     Example 22 Includes the CoMP system of Example 21, wherein the PRS is defined by: 
     
       
         
           
             
               
                 
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     Example 23 includes the CoMP system ofany of Examples 18-22, further comprising: a plurality of fiber-optic links to communicatively couple the eNB to the plurality of RRHs. 
     Example 24 includes a method comprising: receiving a long-term evolution (LTE) positioning protocol (LPP) message that includes an indication of a virtual identifier of a remote radio head (RRH); receiving a positioning reference signal (PRS) from the RRH; processing the PRS based on the virtual identifier; and generating positioning measurement and estimation data based on the processed PRS signal. 
     Example 25 includes the method of Example 24, further comprising: generating a measurement report that includes the positioning measurement and estimation data; and transmitting the measurement report to a serving eNB. 
     Example 26 Includes one or more non-transitory computer-readable media having instructions that, when executed, cause a remote radio head (RRH) to: transmit, via a wireless transceiver, a positioning reference signal (PRS) that is based on a virtual identifier associated with the RRH. 
     Example 27 includes the one or more non-transitory computer-readable media of Example 26, wherein the instructions, when executed, further cause the RRH to periodically transmit the PRS. 
     Example 28 includes the one or more non-transitory computer-readable media of Example 26 or 27, wherein the instructions, when executed, further cause the RRH to: initialize a pseudo-random sequence generator with a first initialization sequence based on the virtual identifier to generate a first pseudo-random sequence; and to generate the PRS based on the first pseudo-random sequence. 
     Example 29 includes the one or more non-transitory computer-readable media of claim  28 , wherein the first initialization sequence is defined by: c init =2 10 *(7*(n s +1)+l+1)*(2*N ID   cellCoMP +1)+2*N ID   cellCoMP +N CP  where n s  is a number of a slot within a radio frame, l is an orthogonal frequency division multiplexing (OFDM) symbol number within the slot, N ID   cellCoMP  is a function of a cell identifier, N ID   cell , and the first virtual identifier, N ID   virtualRRHID , and 
     
       
         
           
             
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     Example 30 includes the one or more non-transitory computer-readable media of claim  29 , wherein the PRS is defined by: 
     
       
         
           
             
               
                 
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     The description herein of illustrated Implementations, Including what is described in the Abstract, is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. While specific implementations and examples are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled In the relevant art will recognize. These modifications may be made to the disclosure in light of the above detailed description.