HK1235607A1 - Resource allocation and use for device-to-device assisted positioning in wireless cellular technologies - Google Patents

Abstract

Techniques described herein may provide for the determination of the position of mobile devices based on information obtained through device-to-device (D2D) discovery or communications. Resource allocation schemes are described that allow efficient communication of signal location parameters, via D2D discovery, communications or newly defined physical channels, that may be used to estimate the position (or improve position estimation) of the mobile device.

Description

Resource allocation and use for device-to-device assisted positioning in wireless cellular technologies

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No. 62/055,053, filed on 25/9/2014, the contents of which are incorporated herein by reference in their entirety.

Background

The wireless network provides network connectivity to mobile communication devices, such as smart phones, via a wireless interface. In wireless networks, a location service that determines the location of a communication device may be a desirable feature. For example, the determination of the location of a mobile device may be important when providing navigation services, emergency services, or other services that can be provided to the mobile device.

In a variety of different situations/environments, accurately determining the location of a mobile device can be challenging. In the specifications promulgated by the third generation partnership project (3GPP), three main types of device location services are described: enhanced Cell Identification (ECID); an assisted global navigation satellite system (A-GNSS); and downlink observed time difference of arrival (OTDOA). However, obtaining accurate position fixes with wireless technology faces numerous challenges that may, in many scenarios, result in coarse location accuracy. These challenges may include poor performance in indoor environments due to high penetration losses, and Non-Line-of-Sight (NLOS) nature of signal propagation from the source of the positioning signal.

Drawings

Embodiments of the present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. For ease of description, like reference numerals may refer to like structural elements. Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

FIG. 1 is a diagram of an example environment in which systems and/or methods described herein may be implemented;

fig. 2 is a flow diagram illustrating an example process for communicating with a device-to-device (D2D) with the assistance of a cellular wireless network for performing location determination;

FIG. 3 is a schematic diagram graphically illustrating the relationship of some of the parameters discussed above that may be used to define the D2D positioning region;

fig. 4 and 5 are diagrams conceptually showing a location beacon of type 1;

fig. 6 and 7 are diagrams conceptually illustrating a type 2 location beacon;

FIG. 8 is a diagram of example components of a device.

Detailed Description

The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. 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. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of embodiments in accordance with the present invention is defined by the appended claims and their equivalents.

The techniques described herein may provide for location determination for a mobile device based on information obtained through device-to-device (D2D) communication. The D2D communications may be referred to herein as "Sidelink (Sidelink) communications" or "Sidelink channels," which may be performed between devices that are also attached to the cellular network. Resource allocation schemes may be set by the cellular network, which schemes described allow for efficient transmission of signal location parameters via D2D communications, which may be used to estimate the location of a mobile device (or to improve location estimation).

In one implementation, consistent with aspects described herein, a UE may include processing circuitry to: connecting with a cellular network; detecting or connecting one or more additional UEs to form a direct connection with the one or more additional UEs; receiving information from the cellular network allocating a portion of the radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters relating to information relating to UE location determination; receiving one or more of the signal location parameters with the allocated portion of the radio spectrum resources via a direct connection with one or more additional UEs; and determining the location of the UE based on the one or more of the received signal location parameters.

In some implementations, the information allocating the portion of the radio spectrum resources may define a periodically occurring D2D positioning region, the D2D positioning region being represented by: an area period value associated with a period in which the D2D positioning area occurs, the area period being defined with respect to a System Frame Number (SFN) of a cell of the cellular network; and a region start offset value that is related to an offset relative to an instance (instance) of the region period. The periodically occurring D2D localization zones may also be represented by: a subframe bitmap indicating specific subframes to be used for exchanging signal location parameters; and an end of area offset value indicating an end location of the subframe bitmap.

In some implementations, the information allocating the portion of the radio spectrum resources may define a periodically occurring D2D positioning region, and wherein the signal location parameters are received as part of a location beacon transmitted with the D2D positioning region. Alternatively or additionally, the D2D location region may be defined with D2D control or data resources or with cellular uplink or downlink spectrum resources during D2D discovery. Alternatively or additionally, the location beacons may each comprise: signal location parameters encoded in the payload data, and demodulation reference signals used to decode the payload data.

In some implementations, the signal location parameters encoded in the payload data include: geographic coordinate information, identification information of a cell associated with a cellular network, information related to signal transmission power, mobility characteristics of a UE, measurements of signal location parameters, transmit/receive timestamps, or information related to a system reference time. Alternatively or additionally, the location beacons may each comprise: signal location parameters encoded in the payload data, demodulation reference signals used to decode the payload data, and positioning reference signals carrying the signal location parameters, the signal location parameters relating to the timing of propagation of the radio signal, the positioning reference signals being represented by demodulation reference signals, sounding reference (sounding reference) signals, Physical Random Access Channel (PRACH) signals, or downlink cell specific (cell specific) reference signals.

In another possible implementation, the UE may include: at least one radio transceiver; a computer readable medium for storing instructions executable by a processor; and processing circuitry to execute the processor-executable instructions to: connecting, with at least one radio transceiver, with a second UE that is proximate to the UE via a sidelink channel; connecting with a cellular network via at least one radio transceiver; and transmitting, via a sidelink channel, a location beacon comprising signal location parameters related to information regarding location determination of the UE, the location beacons transmitted with assigned radio spectrum resources, the location beacon comprising at least one of: positioning reference signals conveying signal location parameters determined based on the timing of propagation of the radio signal, or payload data encoding the signal location parameters.

In another implementation, a method implemented by a UE may include: connecting with a cellular network; connecting with one or more additional mobile devices via a sidelink connection with one or more additional UEs; receiving information from the cellular network allocating a portion of the radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters related to information related to location determination of the mobile device; receiving one or more of the signal location parameters via one of the sidelink connections and with the allocated portion of the radio spectrum resources; and determining a location of the mobile device based on one or more of the received signal location parameters.

In some implementations, the determination of the location of the mobile device includes: transmitting one or more of the received signal location parameters to a location server.

In another implementation, a UE may include: means for connecting to a cellular network; means for connecting one or more additional mobile devices via a sidelink connection with one or more additional UEs; means for receiving information from a cellular network, the information allocating a portion of radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters related to determined information relating to a location of a mobile device; means for receiving one or more of the signal location parameters via one or more of the sidelink connections and with the allocated portion of radio spectrum resources; and means for determining a location of the mobile device based on one or more of the received signal location parameters.

FIG. 1 is a diagram of an example environment 100 in which systems and/or methods described herein may be implemented. As shown, environment 100 may include UEs 110, 112, and 114. Although three UEs are shown in fig. 1, environment 100 may, in fact, include more or fewer UEs.

Environment 100 may also include a wireless network 120. Wireless network 120 may include one or more networks that provide wireless network connectivity to UE110 and 114. For example, wireless network 120 may represent a wireless network that provides cellular wireless coverage. In some implementations, wireless network 120 may be associated with a 3 GPP/Long Term Evolution (LTE) based network. Wireless network 120 may include a Radio Access Network (RAN) that includes one or more base stations 125 and an Evolved Packet Core (EPC). In the context of an LTE-based network, the base station 125 may be referred to as an evolved node b (enb). The EPC may include a Serving Gateway (SGW)130, a Mobility Management Entity (MME)135, and a packet data network gateway (PGW) 140. Also shown in fig. 1 are a Home Subscriber Server (HSS)150 and a location server 160, which may be associated with the EPC, wireless network 120, or a foreign network.

The UEs 110 and 114 may each include portable computing and communication devices, such as Personal Digital Assistants (PDAs), smart phones, cellular phones, laptops with connection to a cellular wireless network, tablets, and so forth. UE110 may also include non-portable computing devices such as desktop computers, consumer or commercial devices, or other devices having the capability to connect to wireless network 120. UE110 and 114 may be connected to wireless network 120 via a radio link.

The UEs 110 and 114 may include a radio interface that allows the UEs 110 and 114 to connect to each other via a direct radio connection. For example, the UEs 110 and 114 may each include a first wireless transceiver to connect to a cellular access network, such as a 3 GPP/Long Term Evolution (LTE) based network (i.e., wireless network 120), and a second radio transceiver to form a D2D communication channel with other UEs. The UEs 110 and 114 may discover each other via direct discovery or with the assistance of the wireless network 120. The UEs 110 and 114 may then directly connect to each other (e.g., via an evolved universal radio access network (E-UTRA) direct communication path that does not use the wireless network 120) to engage in direct D2D communication via a sidelink channel. In some implementations, control information (such as information related to discovery and pairing of the UE110 and 114) may be communicated to the UE110 and 114 via the wireless network 120. Thus, wireless network 120 (such as a cellular network) may facilitate creation and/or management of sidelink channels.

UE110 may correspond to a user wireless terminal such as a smart phone or other device carried by a consumer of a wireless cellular provider (e.g., a wireless cellular provider operating wireless network 120). Alternatively or in addition, UE110 and 114 may comprise fixed devices installed by the operator of wireless network 120 or other parties. In this case, the UE110 and 114 may be an "anchor" terminal that has a known location and is designed to assist other UEs in location determination. In some implementations, the anchor terminal can include a device to: such as intelligent meters, advertising devices that provide advertising in shopping malls, or other devices that are not their basic function for assistance in location determination.

eNB125 may include one or more network devices that receive, process, and/or transmit traffic intended for UE110 and/or received from UE110 and 114. eNB125 may provide a wireless (i.e., radio) interface between wireless network 120 and UE110 and 114.

SGW130 may include one or more network devices that route data of a traffic flow. SGW130 may aggregate traffic received from one or more enbs 125 and may send the aggregated traffic to an external network via PGW 140. SGW130 may also function as a mobility anchor at the time of inter-base station handover.

MME 135 may include one or more computing and communication devices that act as control nodes for eNB125 and/or other devices that provide an air interface for wireless network 120. For example, MME 135 may perform operations of wireless network 120 for UE110 and 114, to establish bearer channels (such as traffic flows) associated with sessions of UE110 and 114, to handover UEs 110-114 to other networks, and/or to perform other operations. The MME 135 may perform policing operations for traffic destined for and/or received from the UE110 and 114.

PGW 140 may include one or more network devices that may aggregate traffic received from one or more SGWs 130 and may send the aggregated traffic to an external network. PGW 140 may also (or alternatively) receive traffic from an external network and may send the traffic to UE110 and 114 via SGW130 and/or eNB 125.

The HSS 150 may include one or more devices that may manage, update, and/or store profile information associated with subscribers in a memory associated with the HSS 150. The profile information may identify the following: applications and/or services that a subscriber is allowed and/or accessible; a Mobile Directory Number (MDN) associated with the subscriber; a threshold of bandwidth or data rate associated with the application and/or service; and/or other information. The subscriber may be associated with UE110 and 114. Additionally or alternatively, the HSS 150 may perform authentication, authorization, and/or accounting operations associated with the subscriber and/or with the session of the UE110 and 114.

Location server 160 may represent functionality implemented by one or more network devices to perform position determination functions for UEs 110-114. For example, location server 160 may receive and store location-determination-related parameters from UE110, eNB125, or from other devices. Some network devices may be located at fixed, known locations. For example, eNB125 and the anchor terminal may be installed at fixed locations. The location server 160 may store the locations of these devices. Location server 160 may periodically or occasionally calculate the location of UE110 and 114 and maintain an up-to-date data structure indicating the current location of UE110 and 114. Based on these parameters or based on known locations of various devices, location server 160 may determine a current location of a target UE (such as one of UEs 110-114) using location calculation techniques, such as a multi-point positioning (localization) based technique. The location server 160 may be implemented as part of the EPC or external to the EPC.

The number of devices and/or networks shown in fig. 1 is provided for purposes of example only. In fact, there may be more devices and/or networks; fewer devices and/or networks; different devices and/or networks; or devices and/or networks arranged differently than shown in fig. 1. Alternatively or additionally, one or more of the devices of environment 100 may perform one or more functions described as being performed by another one or more of the devices of environment 100.

Fig. 2 is a flow chart illustrating example operations 200 for performing location determination for D2D communication with the assistance of a cellular wireless network.

Operation 200 may include configuring spectrum in D2D communications (i.e., in a sidelink channel) for location determination (block 210). For example, the UE110 may be configured to use certain Long Term Evolution (LTE) frames and/or subframes in which signal location parameters may be exchanged. In one implementation, the configuration information may be broadcast or otherwise transmitted to UE110 via wireless network 120 and 114. The configuration information may be used to allocate spectral resources associated with the sidelink channel via which the signal location parameters may be transmitted.

As used herein, a "signal location parameter" may refer to any parameter that can be used as a factor in determining the location of a UE. The signal location parameters may be transmitted via signals transmitted between the base station 125 and the UE110 and 114 or via sidelink channels between the UEs 110-114. A non-exhaustive list of possible signal location parameters includes: signal time of arrival (TOA), time of flight (time of flight), time difference of arrival (TDOA), reference signal time difference, angle of arrival, angle of departure, received reference signal quality, reference signal received power, coordinates of a reference node or anchor node, information related to the eNB, transmission time offsets between enbs or UEs, metrics characterizing time measurement accuracy, identification of serving cells, reference cells, and neighboring cells, GNSS assistance information, timestamps, counter information, desired time windows of arrival, or other information. In some implementations, the signal location parameters may be communicated between UEs on a sidelink channel without the UEs explicitly connecting to each other. For example, a UE may detect a reference signal transmitted by another UE on a sidelink channel.

In one implementation, the D2D spectrum may be configured such that the signal location parameters are transmitted with a relatively low duty cycle (i.e., a relatively long period between transmissions of the signal location parameters) to facilitate power saving processing at the UE transmitter and receiver. The low duty cycle may enable power saving processing by allowing the UE to turn off transceiver circuitry when the UE is only interested in using the sidelink channel for positioning. For example, a battery-powered dedicated anchor terminal may enter a low power usage state when no signal location parameters are scheduled to be transmitted or received. Furthermore, transmitting the signal location parameters with a relatively low duty cycle may provide a relatively large bandwidth for other applications to use the D2D spectrum.

The portion of the D2D spectrum allocated to exchange signal location parameters may be referred to herein as the "D2D location area". The number of subframes and/or Physical Resource Blocks (PRBs) in the D2D location area may be configurable (such as by wireless network 120). In a D2D location area, the time and frequency domain allocations may be arranged in a manner that increases the number of signals received during the D2D location area. For example, D2D may be arranged to locate regions based on maximum matching theory and a greedy resource selection algorithm.

In one implementation, the D2D location areas may be periodically allocated by wireless network 120 (e.g., by eNB125) and as part of the allocation of PRBs. The configuration of the D2D positioning region may be communicated between neighboring enbs 125 or cells to facilitate determination of the inter-cell D2D location. As an example, in one implementation, the configuration of the D2D location area may be aligned across the entire network and coordinated via a backhaul link (back haul) interface.

A number of parameters may be used to define the D2D location area. These parameters may include:

zone Period (Zone Period). In this period, the D2D positioning area may be allocated within a cell. In one implementation, a region period may be defined as a number of frames. For example, the D2D positioning region may occur once every X frames, where X is an integer (e.g., 21, 64, 128, 256, 512, 1024, etc.). The region period parameter may be related to the resource pool of the serving cell as well as the neighboring cells. The starting point of the area period may be defined with respect to a System Frame Number (SFN) of the serving cell of zero. Higher values of the region period may correspond to longer duty cycles and less spectrum used by the location determination process.

Zone Start Offset (Zone Start Offset). An offset indicator in the example of a region period. The region start offset may be specified as a number of frames or subframes offset relative to the boundary of the region period at the start of a subframe bitmap (see below). This parameter may be related to the resource pool of the serving cell.

Zone End Offset (Zone End Offset). Representing an offset indicator at the end of the subframe. This parameter may be related to the resource pool of the serving cell.

Subframe Bitmap (Sub-frame Bitmap). A bitmap, or other data structure or representation, indicates that the subframes have resources reserved for the D2D location determination. The bitmap may refer to a set of subframes that start after an offset indicated by a region start offset. In some implementations, the bitmap may be repeated multiple times in an instance of the region period. This parameter may be related to the resource pool of the serving cell.

The Number of Sub-frame Bitmap Repetitions (Number of Sub-frame Bitmap Repetitions). The number of times the subframe bitmap is repeated in the example of the region period. This parameter may be related to the resource pool of the serving cell.

The Number of Zone PRBs (Number of Zone PRBs). This parameter may define the length of the D2D location region allocation relative to the PRB. This parameter may be related to the location area of the serving cell.

Zone Start prb (zone Start prb). Transmission on a subframe may occur on the following PRBs: these PRBs have an index value greater than or equal to this value and less than the number of region start PRBs plus region PRBs. Region-initiated PRBs may be needed to avoid collisions between Physical Uplink Control Channels (PUCCHs) and/or during D2D discovery, and may be needed to allow frequency division multiplexing between different resource pools. This parameter may be related to the serving cell.

Zone End prb (zone End prb). Transmission on a subframe may occur on the following PRBs: these PRBs have an index value greater than or equal to this value and greater than the number of end-of-region PRBs plus region PRBs. Region-ending PRBs may be needed to avoid collisions between PUCCHs and/or during D2D discovery, and may be needed to allow frequency division multiplexing between different resource pools. This parameter may be related to the resource pool of the serving cell.

The schematic diagram of fig. 3 graphically illustrates the relationship between some of the parameters discussed above that may be used to define the D2D location area. As shown, several D2D positioning zones 310 (each covering one or more subframes) may be defined periodically to have a period equal to the zone period, where the first zone period begins where the SFN equals zero. The region period "boundaries" are shown in fig. 3 with dashed vertical lines. As also shown in fig. 3, in each zone period, a subframe may be used for "location beacon" transmission. The term "location beacon" as used herein will be used to specify the physical structure of UE signaling on the sidelink and/or uplink (e.g., to base station 125) channels used to transmit signal location parameters. The subframes for the location beacon transmission may begin after a zone start offset from the zone period boundary (at the dashed line labeled 320). A subframe bitmap "0101010100" is shown, which may indicate: the second, fourth, sixth, and eighth subframes after the starting point (i.e., the subframe after the dashed line 320 in the bitmap corresponds to a "1") may be used for transmission of the location beacon.

Referring back to fig. 2, process 200 may include transmitting a location beacon with the configured spectrum (block 220). Consistent with aspects described herein, a place beacon may be constructed with one of several options. The specific structure of the location beacons to be employed may be configured in advance and/or communicated by eNB125 as part of a configuration related to location determination. A location beacon may be typically used to transmit: (1) demodulation reference signals (DMRS) that can be used to estimate the signal quality/strength of the channel so that payload data and/or secondary link positioning reference signals (timing information) can be decoded; (2) payload data, which may include signal location parameters (such as UE identity, UE location coordinates, UE motion characteristics, etc.); and/or (3) sidelink positioning reference signals that may be used to derive timing-based signal location parameters (such as timing related to propagation of radio signals). Timing-based signal location parameters may include, for example, signal TOA relative to a synchronized reference clock; signal transit time, TDOA, or other timing-based signal location parameter. The different types of location beacons and the information carried by the different types of location beacons will be described in more detail with reference to fig. 4-7.

Process 200 may also include estimating a location of the UE based on the D2D communication of the location beacon (block 230). As previously mentioned, the signal location parameters may be obtained from a location beacon. In some implementations, the signal location parameters may be transmitted by UE110 and 114 to location server 160 via wireless network 120 (such as via a cellular network). Location server 160 may use signal location parameters obtained from several sources (e.g., several UEs and/or enbs) to obtain the location of a particular "target" UE. For example, location server 160 may obtain a relatively precise three-dimensional location of the target UE using a multilateration-based technique based on signal location parameters obtained from UE110 and/or eNB(s) 125. Alternatively or additionally, in some implementations, the determination of the location may be performed locally by the target UE, based on signal location parameters obtained from a location beacon received by the target UE, and/or based on signal location parameters received via other techniques (e.g., by receiving signal location parameters forwarded by other UEs and/or enbs via bearers communicated over the sidelink channel or wireless network 120).

The structure of the different types of location beacons will be described below. Consistent with aspects described herein, a location beacon may be constructed with one of three signaling layer options, referred to herein as "location beacon type 1", "location beacon type 2", and "location beacon type 3". The contents of the three types of beacons are summarized in table 1.

As shown in table 1, the type 1 location beacon may include signal location parameters in payload data and may employ DMRS. DMRS may be used to estimate channel quality to enable decoding of signal location parameters in payload data. The type 2 location beacon may include a secondary link positioning reference signal (SPRS), a signal location parameter in payload data, and may use a DMRS. Type 3 location beacons may include sidelink positioning reference signals but do not include signal location parameters in the payload data, nor use DMRS.

Fig. 4 and 5 are diagrams conceptually illustrating a type 1 location beacon. In FIG. 4, concepts associated with a single instance of D2D positioning region 310Is shown. The D2D positioning region 310 may be viewed as having both a frequency dimension and a time dimension. As shown, assume that D2D positioning region 310 is populated by a number of separate positioning payload resources (N) in the time domain_PPRTA payload resource, wherein N_PPRTEqual to 2 in fig. 4) and some positioning payload resources in the frequency domain (N)_PPRFA payload resource, wherein N_PPRFEqual to 2 in fig. 4) the payload resources may be conceptualized as forming a grid of possible payload resource blocks (e.g., a 2 × 2 grid in fig. 4)_SFOne LTE subframe or slot (where M_SFIs a positive integer) or any other time unit composition of another granularity. Similarly, positioning payload resources in the frequency domain may be represented by M_PRBOne LTE physical resource block (where M_PRBIs a positive integer) or any other frequency unit of another granularity.

Different UEs 110 and 114 may transmit location beacons with different resource blocks of the D2D positioning region 310. For example, the first UE may use N_PPRT，N_PPRFAnd another UE may use the resource block associated with N_PPRT，N_PPRFPair (1, 2) associated resource blocks. In one implementation, the resource blocks may be selected autonomously by the UE110 and 114, such as by random selection, pseudo-random selection, or selection based on signal quality measurements or other measurements. Alternatively or additionally, the allocation of different resource blocks to different UEs may be performed with the assistance of wireless network 120 (such as through configuration information broadcast by eNB 125).

In fig. 5, a D2D positioning region 510 is shown, with specific resource blocks 520 shown in more detail in this region 510. For resource block 520, M_SFIs equal to 14, M_PRBEqual to 24. M_SFTwo slots equal to 4 and 11 may be used for DMRS. M_SFA slot equal to 14 may be used for transmission gap (gap) symbols. The remaining slots of resource block 520 may be used to transmit symbols as used to transmit signal location parametersA portion of payload data.

As mentioned, for type 1 location beacons, the signal location parameters may be encoded in the payload data. The signal location parameters may relate to information used to implement a location protocol in the environment 100 and may include, for example, one or more of the following:

the geographical coordinates of the UE (whether relative or absolute and whether two-dimensional or three-dimensional);

the movement characteristics of the UE (e.g., velocity [ velocity + direction of movement ], acceleration, etc.);

cell identification information related to a serving cell and/or a reference cell associated with the UE;

a signal propagation Timing value associated with the UE, such as Timing Advance (TA), transit time, signal Round Trip Time (RTT) from the UE to a base station associated with a serving or reference cell, RTT/2 (half of RTT), or other Timing related value that can be used to estimate the distance between the UE and the base station;

reference time information (such as the concept of absolute or system reference time);

timestamp information (e.g., relative or absolute time instance when the UE transmits a location beacon at the UE's antenna port);

the transmit power;

an indication of reference signal received power from a serving, reference, or neighboring cell or terminal, and/or an indication of reference signal received quality;

reference Signal Timing Difference (RSTD) between a cell or anchor UE and a series of detected anchor UEs;

information about the reference node;

forward/reverse timing estimation information for the two-way timing protocol and range estimation;

uncertainty metrics related to the quality of the measured parameters;

the desired window/range for time of arrival and angle of arrival;

other application layer payload or application layer identification information; and

global positioning satellite system (GNSS), such as GPS, assistance information.

In some implementations, the location beacons may be transmitted using an existing Physical Sidelink Discovery Channel (PSDCH). Alternatively or additionally, the location beacon may be transmitted with a new channel, referred to herein as a Physical Sidelink Location Channel (PSLCH). The PSLCH channel design uses a fixed physical structure for transmission of device discovery information, which uses two PRBs and one or two LTE subframes to perform device discovery. The limitation of using two PRBs in PSDCH may not provide an accurate timing estimate due to the rather narrow bandwidth of the DMRS signal. In one implementation, the PSLCH can be defined by a configurable bandwidth for transmitting the location beacons. Also, with PSLCH, the parameter N can be made_PPRT、N_PPRF、M_SFAnd M_PRBMay be configured to be configurable by wireless network 120.

The structure of the type 2 location beacon will be described below. Fig. 6 and 7 are diagrams conceptually illustrating a type 2 location beacon. In fig. 6, the physical structure of D2D location area 610 may be further divided into two sub-areas, labeled as sub-areas 615 and 620. Sub-region 615 may be used to transmit secondary link positioning reference signals (SPRS) and sub-region 620 may be used to transmit payload data (e.g., including similar content to those discussed for type 1 location beacons). Sub-region 615 may precede sub-region 620 or follow sub-region 620. In the latter scenario, the target UE, upon detecting an anchor terminal (such as a fixed-location UE that is assisting in D2D positioning), may improve the accuracy of the signal location parameters obtained from the payload data by processing the secondary link positioning reference signal. Alternatively, the target UE may attempt to first detect the sub-region 620 and then decode only those payload resources corresponding to the detected secondary link positioning reference signal. There may be a one-to-one mapping between positioning reference signal resources or between sequences and positioning payload resources so that the target UE can know the location of one by detecting the other.

With type 2 location beacons, signal location parameters may be estimated based on both sidelink positioning reference signals and payload parameters. As mentioned, the payload may carry the same information as described for the type 1 location beacon.

The physical structure of the positioning reference signal may be different from the structure of the payload and the DMRS signal. For example, and as shown in fig. 6, the bandwidth of the secondary link positioning reference signal may be increased relative to the bandwidth of the resource blocks of the payload parameter. In one implementation, the bandwidth of the sidelink positioning reference signal may be configured with higher layer signaling. In some implementations, the sidelink positioning reference signal may not occupy the entire subframe, but rather employ some symbols. This may increase the degree of freedom in time division multiplexing (i.e. orthogonality in the time domain) and facilitate a more accurate determination of the signal location parameters due to the possibility of transmission over a larger bandwidth. In some implementations, transmission of the secondary link positioning reference signal may require at least three symbols, where at least a portion of the first symbol may be used to adjust Automatic Gain Control (AGC) settings, and at the end of the secondary link positioning reference signal transmission, additional symbols may be added so as to allow some time for transmit-receive or receive-transmit transitions.

The D2D positioning area 710, which includes sub-areas 715 and 720, is shown in fig. 7, where the following are shown: a specific resource block 730, which corresponds to a resource block for transmitting a secondary link positioning reference signal; and resource blocks 740, which correspond to the resource blocks used to transmit the payload data. For resource block730, the number of symbols used in the transmission of the sidelink positioning reference signal is determined by a parameter L_sAs shown. The number of allocated physical resource blocks used in the transmission of the secondary link positioning reference signal is determined by a parameter L_PRBAs shown. Resource block 740 may be defined by a parameter M_SFAnd M_PRBThese parameters, as defined, correspond to the same parameters used in type 1 location beacons.

Some physical sequences for sidelink positioning reference signal transmission may potentially be employed, including: existing DMRS signals with larger bandwidths, sounding reference signals, Physical Random Access Channel (PRACH) signals, and/or secondary link synchronization signals (primary and secondary). Alternatively or additionally, the new signal may be designed based on: Zadoff-Chu sequences, Golay sequences, complementary Golay sequences, m-sequences, or other pseudo-random sequences with good auto-and cross-correlation properties. Parameters (e.g., L) for secondary link positioning reference signals_PRBAnd L_s) May be configured through higher layer signaling, such as Radio Resource Control (RRC) or System Information Block (SIB) signaling, or predefined (e.g., in a specification).

The structure of the type 3 location beacon will be discussed below. For type 3 location beacons, the signal location parameters may be derived from the sidelink positioning reference signal (rather than from the payload data). The secondary link positioning reference signals from different UEs may be multiplexed in a time-frequency manner that allows for efficient interference management, resource utilization, and half-duplex schemes. The granularity of allocation in the time and frequency domains may be signaled by higher layers through a parameter L in a manner similar to that discussed with respect to type 2 location beacons_PRBAnd L_sAnd (5) controlling. Alternatively or additionally, L_PRBAnd L_sThe value of (d) may be predefined.

In general, a wider signal bandwidth can be configured for the transmission of the sidelink positioning reference signal, which can result in better timing resolution (timing resolution). A larger bandwidth may result in greater accuracy given the condition of a constant signal-to-noise ratio. The frequency location of each transmission may be varied in time so that the accuracy of the timing estimate can be improved when the receiver employs multi-shot processing.

In type 3 location beacons, detected sidelink positioning reference signals may be encoded to indicate the identity of the transmitter, enabling differentiation between different transmitting UEs. Alternatively or additionally, a predefined relationship between spectral resources (i.e., coordinates of the frequency and time domains of the secondary link positioning reference signal allocation) and the identity of the transmission point (such as a UE) may be known. For example, eNB125 may broadcast a mapping that associates transmission points with time-frequency domain resources and/or sequences.

Wireless network 120 (e.g., via eNB125) may activate some of UEs 110 and 114 (such as anchor UEs/terminals with fixed locations and known coordinates) to transmit the sidelink positioning reference signals with predefined resources and/or with predefined transmission sequences. The eNB125 may also request that a UE, such as one of the UEs 110 and 114 (such as a particular target UE), measure the signal location parameters for each sidelink positioning reference signal time-frequency domain resource and/or sequence, and then report the results of this measurement to the eNB125 for further estimation of the UE coordinates by the location server 160. In some aspects, the eNB125 may allocate synchronization resources to periodically transmit sidelink synchronization signals (primary and secondary), timing reference signals, or DMRS signals to perform measurements of signal location parameters at the target UE.

Fig. 8 is a diagram of components of an example of a device 800. Each of the devices shown in fig. 1 may include one or more devices 800. Device 800 may include a bus 810, a processor 820, a memory 830, an input component 840, an output component 850, and a communication interface 860. In another implementation, device 800 may include more, fewer, different, or differently arranged components.

Bus 810 includes one or more communication paths that allow communication among the components of device 800. Processor 820 may include a processor, microprocessor, or processing logic or circuitry capable of interpreting and executing instructions. Memory 830 may include any type of dynamic storage device that may store information and instructions for execution by processor 820 and/or any type of non-volatile storage device that may store information for use by processor 820. The term "processing circuitry" as used herein may generally refer to a processor and/or hardwired logic in which the functionality of the hardwired logic is defined by an arrangement of circuits associated with the hardwired logic by execution of instructions to perform a function.

Input assembly 840 may include mechanisms, such as a keyboard, keypad, keys, switches, etc., that allow an operator to input information to device 800. Output component 850 may include a mechanism that outputs information to an operator, such as a display, a speaker, one or more Light Emitting Diodes (LEDs), and so forth.

Communication interface 860 may include any transceiver-like mechanism that enables device 800 to communicate with other devices and/or systems. For example, communication interface 860 may include an ethernet interface, an optical interface, a coaxial interface, and so forth. Communication interface 860 may include a wireless communication device, such as an Infrared (IR) receiver, a cellular radio, a bluetooth radio, or the like. The wireless communication device may be coupled to an external device such as a remote control, a wireless keyboard, a mobile phone, and the like. In some embodiments, device 800 may include more than one communication interface 860. For example, device 800 may include an optical interface and an ethernet interface.

The device 800 may perform certain operations described above. Device 800 may perform these operations in response to processor 820 executing software instructions stored in a computer-readable medium, such as memory 830. The computer readable medium may be defined as a non-transitory memory device. The memory devices may be included in a single physical memory device or span the space of multiple physical memory devices. The software instructions may be read into memory 830 from another computer-readable medium or from another device. The software instructions stored in memory 830 may cause processor 820 to perform processes described herein. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement processes described herein. Thus, implementations described herein are not limited to any specific combination of hardware circuitry and software.

In the foregoing specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

For example, while a series of blocks has been described with respect to fig. 2, the order of the blocks may be modified in other implementations. Furthermore, blocks without dependencies may be executed in parallel.

It should be apparent that aspects of the examples described above may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement these aspects should not be construed as limiting. Thus, the operation and behavior of the aspects were described without reference to the specific software code — it being understood that software and control hardware may be designed to implement the aspects in accordance with the aspects of the description.

Furthermore, certain portions of the invention may be implemented as "logic" that performs one or more functions. This logic may include hardware, such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA), or a combination of hardware and software.

Although specific combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the invention. Indeed, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification.

No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Furthermore, the word "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.

Claims (21)

1. A User Equipment (UE), comprising processing circuitry to:

connecting a cellular network;

detecting or connecting one or more additional UEs to form a direct connection with the one or more additional UEs;

receiving information from the cellular network allocating a portion of radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters relating to information relating to UE location determination;

receiving one or more of the signal location parameters via a direct connection with the one or more additional UEs and with the allocated portion of the radio spectrum resources; and

determining a location of the UE based on one or more of the received signal location parameters.

2. The UE of claim 1, wherein the information allocating portions of radio spectrum resources defines a periodically occurring device-to-device (D2D) location area, represented by:

an area period value related to a period in which the D2D positioning area occurs, the area period defined with respect to a System Frame Number (SFN) for a cell of the cellular network; and

a region start offset value associated with an offset relative to an instance of the region period.

3. The UE of claim 2, wherein the periodically occurring D2D positioning regions are further represented by:

a subframe bitmap indicating specific subframes to be used for exchanging the signal location parameters; and

an end of area offset value indicating an end location of the subframe bitmap.

4. The UE of claim 1, wherein the information allocating portions of radio spectrum resources defines a periodically occurring device-to-device (D2D) positioning region, wherein the signal location parameters are received as part of a location beacon transmitted with the D2D positioning region.

5. The UE of claim 4, wherein the D2D positioning region is defined with D2D control or data resources or with cellular uplink or downlink spectrum resources during D2D discovery.

6. The UE of claim 4, wherein each of the location beacons includes:

signal location parameters encoded in the payload data; and

a demodulation reference signal used to decode the payload data.

7. The UE of claim 5, wherein the signal location parameters encoded in the payload data comprise:

geographic coordinate information;

identification information of a cell associated with the cellular network;

information related to signal transmit power;

a mobility characteristic of the UE;

a measurement of a signal location parameter;

a transmit/receive timestamp; or

Information relating to a system reference time.

8. The UE of claim 4, wherein each of the location beacons includes:

signal location parameters encoded in the payload;

a demodulation reference signal used for decoding the payload data; and

a positioning reference signal carrying signal location parameters related to propagation timing of a radio signal and represented by a demodulation reference signal, a sounding reference signal, a Physical Random Access Channel (PRACH) signal, or a downlink cell-specific reference signal.

9. The UE of claim 4, wherein each of the location beacons is comprised of:

a positioning reference signal carrying signal location parameters related to propagation timing of a radio signal and represented by a demodulation reference signal, a sounding reference signal, a Physical Random Access Channel (PRACH) signal, or a downlink cell-specific reference signal.

10. A method implemented by a mobile device, comprising:

connecting a cellular network;

connecting with one or more additional mobile devices via a sidelink connection with one or more additional UEs;

receiving information from the cellular network allocating a portion of radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters related to information related to mobile device location determination;

receiving one or more of the signal location parameters via one of the sidelink connections and with the allocated portion of the radio spectrum resources; and

determining a location of the mobile device based on one or more of the received signal location parameters.

11. The method of claim 10, wherein determining the location of the mobile device comprises: transmitting one or more of the received signal location parameters to a location server.

12. The method of claim 10, wherein the information allocating portions of radio spectrum resources defines a periodically occurring device-to-device (D2D) location area defined by:

an area period value related to a period in which the D2D positioning area occurs, the area period defined with respect to a System Frame Number (SFN) of a cell of the cellular network; and

a region start offset value associated with an offset relative to an instance of the region period.

13. The method of claim 12, wherein the periodically occurring D2D localization areas are further represented by:

a subframe bitmap indicating specific subframes to be used for exchanging the signal location parameters; and

an end of area offset value indicating an end location of the subframe bitmap.

14. The method of claim 10, wherein the information allocating portions of radio spectrum resources defines a periodically occurring device-to-device (D2D) positioning region, wherein the signal location parameters are received as part of a location beacon transmitted with the D2D positioning region.

15. The method of claim 14, wherein each of the location beacons includes:

signal location parameters encoded in the payload data; and

a demodulation reference signal used to decode the payload data.

16. The method of claim 15, wherein the signal location parameters encoded in the payload data comprise:

geographic coordinate information;

identification information of a cell associated with the cellular network;

information related to signal transmit power;

a mobility characteristic of the UE;

a measurement of a signal location parameter;

a transmit/receive timestamp; or

Information relating to a system reference time.

17. The method of claim 10, wherein each of the location beacons includes:

signal location parameters encoded in the payload data;

a demodulation reference signal used for decoding the payload data; and

a positioning reference signal that conveys a signal location parameter related to a propagation timing of a radio signal and is represented by a demodulation reference signal, a sounding reference signal, a Physical Random Access Channel (PRACH) signal, or a downlink cell-specific reference signal.

18. A User Equipment (UE), comprising:

means for connecting to a cellular network;

means for connecting one or more additional mobile devices via a sidelink connection with one or more additional UEs;

means for receiving information from the cellular network allocating a portion of radio spectrum resources as radio spectrum resources dedicated to exchanging signal location parameters relating to information relating to mobile device location determination;

means for receiving one or more of the signal location parameters via one of the sidelink connections and with the allocated portion of the radio spectrum resources; and

means for determining a location of the mobile device based on one or more of the received signal location parameters.

19. The UE of claim 18, wherein the information allocating portions of radio spectrum resources defines a periodically occurring device-to-device (D2D) positioning region, wherein the signal location parameters are received as part of a location beacon transmitted with the D2D positioning region.

20. The UE of claim 18, wherein each of the location beacons includes:

signal location parameters encoded in the payload data; and

a demodulation reference signal used to decode the payload data.

21. The UE of claim 17, wherein each of the location beacons includes:

signal location parameters encoded in the payload data;

a demodulation reference signal used for decoding the payload data; and

a positioning reference signal that conveys a signal location parameter related to a propagation timing of a wireless signal and is represented by a demodulation reference signal, a sounding reference signal, a Physical Random Access Channel (PRACH) signal, or a downlink cell-specific reference signal.