Using ranging signals to locate vehicles and pedestrians

Abstract

A target user equipment (UE), which may be a UE carried by a vehicle or a pedestrian, may receive ranging signals broadcast sequentially from a group of ranging source entities (SEs), which may be roadside units or other vehicles. The target UE further receives location information broadcasted by each SE respectively. The location information may include, for example, the location of the SE, the transmission time of the ranging signal transmitted by the SE, and / or a sequence identifier of the SE. The target UE may determine the distance to the SE using the arrival time measurement value of the ranging signal and the transmission time or the sequence identifier of the ranging signal received in the location information. The location of the target UE may be determined using the determined distance to the SE and the location of the SE received in the location information.

Description

[0001] Priority claim

[0002] This patent application claims priority to U.S. Non-Provisional Application No. 16 / 698,295, filed on November 27, 2019, entitled “POSITIONING OF VEHICLES AND PEDESTRIANS LEVERAGING RANGING SIGNAL,” which is assigned to the assignee of this patent application and is expressly incorporated herein by reference. Technical Field

[0003] The subject matter disclosed herein relates to wireless communication systems, and more particularly to methods and apparatus for location determination of user equipment in wireless communication systems. Background Art

[0004] In the communications industry, it is becoming increasingly common to obtain accurate location information of user devices, such as cellular phones or other wireless communication devices. For example, obtaining highly accurate locations of vehicles or pedestrians is critical for autonomous vehicle driving and pedestrian safety applications.

[0005] A common method of determining the location of a device is to use a satellite positioning system (SPS), such as the well-known Global Positioning Satellite (GPS) system or the Global Navigation Satellite System (GNSS), which employs many satellites in orbit around the earth. However, in some cases, the location determination signal from the SPS may not be available, such as in areas where satellite signal reception is poor (such as tunnels or parking lots). In addition, the location information generated using the SPS is prone to inaccuracy. For example, the accuracy of existing GPS positioning devices is only a few meters, which is not optimal for ensuring safe autonomous driving and navigation.

[0006] To improve the accuracy of location determination, it may be desirable to use signals from one or more ground sources. For example, a signal used to determine the distance to a fixed roadside unit or the distance from a moving vehicle with a known location can be used by a target vehicle or pedestrian to locate. For example, round trip time (RTT) is a technique that is commonly used to determine the location of a target vehicle or pedestrian. RTT is a two-way messaging technique in which the time between sending a signal from a first device and receiving an acknowledgment from a second device (minus processing delays) corresponds to the separation (distance) between the two devices. While RTT is accurate, it is desirable to reduce the power consumption required for two-way messaging. Summary of the invention

[0007] A target user equipment (UE), which may be a UE carried by a vehicle or a pedestrian, may receive ranging signals broadcast sequentially from a group of ranging source entities (SEs), which may be roadside units or other vehicles. The ranging signal may be a broadband signal having a continuous or non-continuous frequency channel. The target UE further receives location information broadcasted by each SE respectively. The location information may include, for example, the location of the SE, the transmission time of the ranging signal transmitted by the SE, and / or a sequence identifier of the SE. The target UE may determine the distance to the SE using the arrival time measurement value of the ranging signal and the transmission time or the sequence identifier of the ranging signal received in the location information. The location of the target UE may be determined using the determined distance to the SE and the location of the SE received in the location information.

[0008] In one implementation, a method for performing location determination by a user equipment (UE) includes: receiving a ranging signal broadcast by each of a plurality of entities in a wireless network; receiving a message with location information broadcast from each of the plurality of entities; determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and determining a position of the user equipment based on the distance to each entity and a known location of each entity.

[0009] In one implementation, a user equipment (UE) configured to support location determination includes: a wireless transceiver configured to receive broadcast signals from entities in a wireless network; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to: receive a ranging signal broadcast by each of a plurality of entities in the wireless network; receive a message with location information broadcast from each of the plurality of entities; determine a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and determine a location of the user equipment based on the distance to each entity and the known location of each entity.

[0010] In one implementation, a user equipment (UE) configured to support location determination includes: a component for receiving a ranging signal broadcast by each of a plurality of entities in a wireless network; a component for receiving a message with location information broadcast from each of the plurality of entities; a device for determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and a component for determining a position of the user equipment based on the distance to each entity and a known location of each entity.

[0011] In one implementation, a non-transitory computer-readable medium including program code stored thereon, the program code being operable to configure at least one processor in a user equipment (UE) to perform location determination, comprising: program code to receive a ranging signal broadcast by each of a plurality of entities in a wireless network; program code to receive a message with location information broadcast from each of the plurality of entities; program code to determine a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and program code to determine a position of the user equipment based on the distance to each entity and a known location of each entity.

[0012] In one implementation, a method of supporting location determination of a user equipment (UE) performed by an entity in a wireless network includes: determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE; generating a ranging signal on the available portion of the wireless spectrum; broadcasting the ranging signal to be received by the UE; and broadcasting a message having location information associated with the ranging signal.

[0013] In one implementation, an entity in a wireless network capable of supporting location determination of a user equipment (UE) includes: a wireless transceiver configured to broadcast a signal to UEs in the wireless network; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to: determine, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE; generate a ranging signal on the available portion of the wireless spectrum; broadcast the ranging signal to be received by the UE; and broadcast a message having location information associated with the ranging signal.

[0014] In one implementation, an entity in a wireless network capable of supporting location determination of a user equipment (UE) comprises: means for determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE; means for generating a ranging signal on the available portion of the wireless spectrum; means for broadcasting the ranging signal to be received by the UE; and means for broadcasting a message having location information associated with the ranging signal.

[0015] In one implementation, a non-transitory computer-readable medium including program code stored thereon, the program code being operable to configure at least one processor in an entity in a user equipment (UE) wireless network to support location determination of the user equipment (UE), comprising: program code for determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE; program code for generating a ranging signal on the available portion of the wireless spectrum; program code for broadcasting the ranging signal to be received by the UE; and program code for broadcasting a message having location information associated with the ranging signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Non-limiting and non-exhaustive aspects are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified.

[0017] Figure 1 A wireless communication system is illustrated in which a target user equipment (UE), shown as a vehicle, wirelessly communicates with other entities in the wireless communication system.

[0018] Figure 2 Illustrated is a simplified environment and exemplary techniques for determining a location of a target UE using single-sided ranging signals from multiple entities in a wireless communication system.

[0019] Figure 3 An example of a call flow for a location determination session with a target UE and a set of entities in a wireless communication system is illustrated.

[0020] Figure 4 is a flow chart illustrating a method of performing location determination by a user equipment.

[0021] Figure 5 is a flow chart illustrating a method of supporting location determination of a user equipment by an entity in a wireless network.

[0022] Figure 6 is a diagram illustrating an example of a hardware implementation of a user equipment capable of performing positioning using sequentially broadcast ranging signal broadcasts.

[0023] Figure 7 is a diagram illustrating an example of a hardware implementation of a ranging source entity capable of supporting location determination of a user equipment using sequentially broadcast ranging signals. DETAILED DESCRIPTION

[0024] The location of a target vehicle or pedestrian can be determined using a single-sided ranging signal from a transmitter with a known location, such as a fixed roadside unit (RU) or a moving vehicle with a known location. The use of a single-sided ranging signal reduces power consumption compared to conventional ranging methods such as the round-trip time (RTT) technique because no confirmation signals need to be sent or received.

[0025] To improve ranging performance and reduce channel access overhead, participating entities may be clustered for sequential transmission of their ranging signals. The ranging signal may be a broadband waveform with multiple continuous or non-contiguous channels. After broadcasting the ranging signal, each entity may further broadcast a message including location information, such as the entity's location, sequence ID, and time of transmitting the ranging signal, so that a target device may determine the distance to the entity.

[0026] Figure 1 A wireless communication system 100 is illustrated in which a target user equipment (UE) 102, shown as a vehicle, communicates wirelessly with other entities 104 and 106 in the wireless communication system 100. As shown, the target UE 102 may communicate directly with an entity 104, shown as a roadside unit (RSU) 104, using a vehicle-to-infrastructure (V2I) communication link 105, and may communicate directly with an entity 106, shown as another vehicle 106, using a vehicle-to-vehicle (V2V) communication link 107. A roadside unit (RSU) is a fixed infrastructure entity that may support V2X applications and may exchange messages with other entities that support V2X applications. The RSU may be a logical entity that may combine V2X application logic with the functionality of a base station in a radio access network (RAN), such as an evolved Node B (eNB) or next generation evolved Node B (ng-eNB) in LTE radio access and / or an evolved LTE (eLTE) radio access (referred to as an eNB-type RSU) or NR Node B (gNB) in fifth generation (5G) radio access, or a user equipment (UE) (referred to as a UE-type RSU). The target UE 102 may communicate with additional entities, such as additional RSUs, vehicles, or pedestrians (not shown), for example, in a vehicle-to-pedestrian (V2P) communication link.

[0027] Wireless communications may be conducted over, for example, the Proximity Based Services (ProSe) Directional Communications (PC5) reference point defined in the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.303, and may use wireless communications under IEEE 1609, Wireless Access in Vehicular Environments (WAVE), Intelligent Transport Systems (ITS), and IEEE 802.11p in the 5.9 GHz ITS band, or other wireless connections directly between entities.

[0028] For positioning of the target UE 102, the ranging source equipment (SE, such as entities 104 and 106) may transmit a one-sided ranging signal, i.e., without transmitting an acknowledgement message in response to the ranging signal. For example, the ranging signal may be transmitted on an unlicensed spectrum. Conventionally, transmissions on an unlicensed spectrum are subject to a listen-before-talk (LBT) procedure prior to transmission. For example, typically, before transmitting on a medium, a radio transmitter needs to first sense the medium, and only transmit when the medium is sensed to be idle, sometimes referred to as a clear channel assessment (CCA). If all SEs (e.g., RSU 104 and vehicle 106) transmit their ranging signals independently, each will be required to perform an LBT procedure separately before transmitting, resulting in inefficient channel access and possibly prohibiting timely distribution of ranging signals.

[0029] Due to the mobility of the target UE 102 (which may be, for example, a vehicle or a pedestrian) and the possible mobility of the SE (e.g., vehicle 106), multiple ranging signals should arrive at the target UE 102 within a reasonably small time window, i.e., such that the target UE 102 (or SE) moves an acceptable amount between the reception of ranging signals; otherwise, ranging performance may be degraded. In addition, the overhead of the LBT procedure depends on the number of entities. Therefore, in order to improve ranging performance and reduce channel access overhead, participating entities (i.e., SEs) are clustered for sequential transmission of their ranging signals.

[0030] In addition, the unlicensed spectrum can be composed of component channels, for example, an 80 MHz unlicensed spectrum has components of 4×20 MHz channels and 2×40 MHz channels. Other wireless nodes may transmit on any component channel at any given time. For example, the entire 80 MHz, or one or more 20 MHz channels, or one or more 40 MHz channels may be occupied. To avoid interference with transmissions from other wireless nodes, the SE may use a subset of the 20 MHz component channels that have free transmissions, such as determined by a single SE, such as the first or beginning SE in a cluster of SEs.

[0031] The target UE 102 monitors the time of arrival (TOA) of each single-sided ranging signal, but the transmission time of the ranging signal is unknown to the target UE 102. Therefore, in addition to broadcasting the ranging signal, the SE also broadcasts location information that can be used by the target UE 102 to determine the distance to each SE. For example, the SE can broadcast the exact time at which the ranging signal is transmitted, and the target UE 102 can use the time together with the TOA of the ranging signal to determine the flight time, which can be converted into the distance to the SE. Therefore, the target UE 102 can always monitor the channel of the ranging signal. Close in time to the broadcast of the ranging signal from the SE (e.g., before or after), each SE sends the location information of its ranging signal. For example, the location information may include the transmission time of the ranging signal, the location of the SE, the bandwidth used in the ranging signal, or other configuration information, etc. Using the location information of the ranging signal from the SE, such as the transmission time of the ranging signal, and using the arrival time of the ranging signal measured by the target UE 102, the target UE 102 can back-calculate the flight time of the ranging signal and thus calculate the distance to each SE.

[0032] In some implementations, for example, if location information is transmitted by one or more SEs before broadcasting a ranging signal, the location information broadcast by the one or more SEs may include a sequence identifier of the SE in addition to or instead of the time at which the ranging signal was transmitted. The sequence identifier indicates the SE position in the broadcast sequence of the ranging signal from the SE cluster. For example, if the transmission time is not included in the location information, the SE i Sequence identifier seq# i For example, it can be used by the target UE 102 to calculate the SE i For example, the target UE 102 may be provided with the transmission time T0 of the first ranging signal (e.g., in the location information from the first or leading SE), and the time T between each ranging signal transmission. trans The emission time of any SE can then be determined, for example as T0+(seq# i *T trans ).

[0033] The location information broadcast by the SE may also include, for example, the location of the SE. In addition, in some implementations, the SE may further include the TOA of one or more ranging signals from other SEs measured by the SE in the location information or in a different message. The location information may be transmitted by the SE in a licensed spectrum, such as in an Intelligent Transport System (ITS) spectrum.

[0034] Figure 2A simplified environment and exemplary techniques for determining the location of a target UE 102 using single-sided ranging signals from multiple entities in a wireless communication system 200 are illustrated. The target UE 102 may communicate wirelessly with a SE including a first RSU 104-1, a second RSU 104-2, and another vehicle 106 having a known location using radio frequency (RF) signals and standardized protocols for RF signal modulation and information packet exchange. By extracting different types of information from the exchanged signals and utilizing the layout of the network (i.e., network geometry), the target UE 102 may determine its location in a predefined reference coordinate system. As shown in FIG. Figure 2 As shown, the target UE 102 may use a two-dimensional coordinate system to specify its position (x, y); however, the aspects disclosed herein are not limited thereto and may also be adapted to use a three-dimensional coordinate system to determine the position if additional dimensions are required. Figure 2 Three entities are shown in FIG, but various aspects may utilize additional entities. For example, three SEs may be used to determine a position (x, y) in a two-dimensional coordinate system, while four or more SEs may be used to determine a position (x, y, z) in a three-dimensional coordinate system. However, in some implementations, less than three SEs may be used, for example, in conjunction with SPS positioning or another positioning system, to determine the precise position of the target UE. For example, if SPS positioning produces a relatively inaccurate position for the target UE, ranging signals from two SEs or a single SE may be used to improve the position accuracy of the target UE.

[0035] To determine its position (x, y), the target UE 102 needs to determine the distance (spacing) (dk, where k=1, 2, 3) and network geometry to each entity 104-1, 104-2, and 106. The network geometry may include the position ((xk, yk), where k=1, 2, 3) of each of the entities 104-1, 104-2, and 106 in a reference coordinate system.

[0036] As shown, each SE 104-1, 104-2, and 106 broadcasts RF signals 201, 202, and 203, respectively, which are received by the target UE 102. The RF signals 201, 202, and 203 include a single-sided ranging signal from each entity 104-1, 104-2, and 106. For example, the ranging signal can be a positioning reference signal (PRS) or a sounding reference signal (SRS) used in the long-term evolution (LTE) defined in 3GPP. As discussed above, the target UE 102 can measure the TOA of the ranging signal. Each SE 104-1, 104-2, and 106 also broadcasts location information, which the target UE can use to determine the flight time of the ranging signal. For example, the location information can include the transmission time and / or a sequence identifier of the SE from which the transmission time can be determined.

[0037] Using the flight time of the ranging signal, the separation between the target UE 102 and the SE can be determined, for example, based on the speed of light. Figure 2 As shown, the distance (distance) (dk, where k=1, 2, 3) to each entity 104-1, 104-2, and 106 can be determined. Once each distance is determined and the network geometry is known, such as the position (xk, yk), where k=1, 2, 3 for each of the entities 104-1, 104-2, and 106 is known, the target UE 102 can solve for its position (x, y) by using various known geometric techniques such as, for example, triangulation. From Figure 2 It can be seen that the location of the target UE 102 is ideally located at the common intersection of all circles 202, 204, and 206 drawn using dotted lines. Each circle is defined by a radius dk and a center (xk, yk), where k = 1, 2, 3. In practice, due to noise and other errors in the networking system, the intersection of these circles may not be at a single point. Network geometry, such as the location (xk, yk), where k = 1, 2, 3 for each of the entities 104-1, 104-2, and 106, can also be provided in the broadcast location information. Using the locations of the entities 104-1, 104-2, and 106 and the intersection of the circles 202, 204, and 206 around the SEs 104-1, 104-2, and 106, the location of the target UE 102 can be determined.

[0038] In some implementations, the single-sided ranging signal can be used with other types of positioning procedures. For example, the single-sided ranging signal and positioning can be used together with SPS positioning. For example, if a relatively imprecise location has been obtained for the target UE using SPS, such as an error of several meters, the single-sided ranging signal and positioning can be used to improve the obtained location, such as reducing the error to tens of centimeters.

[0039] In order to generate the ranging signal to be used by the target UE 102, a cluster or group of ranging SEs is established. Figure 2 , a group of SEs may be established as roadside units 104-1, 104-2 and vehicle 106. In some implementations, for example, the group of SEs may be able to transmit ranging waveforms in an unlicensed spectrum and transmit location information in a licensed spectrum. For example, the group of SEs may be physically close to each other. The group of SEs may be a group of one, i.e., the group may include a single roadside unit 104 or a single vehicle 106.

[0040] The group of SEs may include a leading SE, such as Figure 2The RSU 104-1 in the roadside unit may be selected arbitrarily or according to predetermined criteria. For example, a specific roadside unit may be given priority as the starting SE. The starting SE 104-1 may be enabled to sense the received signal power (frequency resources) of the channels in the spectrum on which the ranging signal will be transmitted, which spectrum may be unlicensed. The starting SE 104-1 detects the energy levels of different channels in the spectrum. The starting SE 104-1 generates a broadband ranging signal that may be of short duration based on the energy levels of the different channels detected. The ranging waveform may consist of one or more unoccupied channels. If one or more channels are considered to be "occupied", a ranging waveform is generated by puncturing the occupied channels, that is, a ranging waveform is generated without occupied channels, so that the ranging waveform uses only "unoccupied" or "idle" channels. Therefore, the ranging waveform may include multiple channels, which may be continuous or discontinuous. The generated ranging signal may be transmitted on demand or may be transmitted multiple times (eg, periodically) by the group of SEs, wherein the ranging signals may have the same channel configuration or may have different channel configurations.

[0041] The generated ranging signal may include a preamble including an indication of the channel used in the ranging signal, and an indication that the channel will be occupied for a period of time, e.g., the time it will take for each SE in the group of SEs to sequentially transmit their individual ranging signals. For example, if each ranging signal is 2 ms long, and there are five SEs in the group of SEs that will sequentially transmit their ranging signals, the preamble may indicate that the channel will be occupied for 10 ms, or slightly longer, to provide some additional configuration time for the SEs to acknowledge the ranging signals transmitted in the cluster.

[0042] Each non-head SE in the group of SEs, such as RSU 104-2 and vehicle 106, may be arbitrarily assigned a sequence identifier that indicates the location of the SE in the sequence of ranging signal transmissions. For example, in one implementation, the sequence of SEs may be based in part on a predetermined identifier for each SE, which may be assigned (or self-assigned) prior to the process. For example, the predetermined identifier may be determined as a layer 2 identifier (L2 ID) mod#SE. For example, in Figure 2, the RSU 104-2 may be assigned a second position, such as a position immediately following the leading SE 104-1, and the vehicle 106 may be assigned a third position. Each SE 104-2 and the vehicle 106 may determine the channels to be included in the ranging waveform based on the broadcast ranging signal received from the leading SE 104-1 (or from any previous SE). For example, the SE 104-2 and the vehicle 106 may determine the available channels, i.e., the portion of the wireless spectrum used for the ranging signal, by examining the ranging waveform from the previous SE or by examining the preamble of the ranging signal from the previous SE. Each SE 104-2 and 106 independently generates the ranging signal using the determined available channels. The ranging signal may be similar to a PRS or an SRS. In one implementation, the ranging signal may also depend in part on a predetermined identifier. For example, the ranging signal may be a base sequence with a cyclic shift, the cyclic shift being determined as L2 ID mod N, where N is a code division multiplexing (CDM) factor (e.g., N=3 cyclic shifts per base sequence). Each SE 104-2 and 106 may also generate a preamble that indicates the channel used in the ranging signal and, in some implementations, the remaining time that the channel will be occupied.

[0043] Each SE in the group of SEs broadcasts its own ranging signal in sequence according to the sequential identifier of the SE. For example, the ranging signal can be broadcast sequentially at 160 MHz or other frequencies. For example, the ranging signal can be broadcast so that the ranging signals have no time overlap. The leading SE 104-1 broadcasts its ranging signal, which may include a preamble. After detecting the first ranging signal from the leading SE 104-1, the remaining SEs 104-2, 106 broadcast their own ranging signals in sequence, for example, SE 104-2 broadcasts its ranging signal immediately after receiving the ranging signal from the leading SE 104-1, and SE 106 broadcasts its ranging signal a time ((Seq#)*T) after receiving the ranging signal from the leading SE 104-1. Trans ) broadcasts its ranging signal, where Seq# is the sequence number of SE, and T Trans is the length of time each ranging signal is transmitted. In some implementations, each remaining SE 104-2, 106 may broadcast its own ranging signal immediately after receiving a ranging signal from an immediately preceding SE, e.g., SE 104-2 broadcasts its ranging signal immediately after receiving a ranging signal from the leading SE 104-1, and SE 106 broadcasts its ranging signal immediately after receiving a ranging signal from SE 104-2.

[0044] Each SE in the group of SEs is also configured to broadcast location information to be used by the target UE 102, including information for ranging signals and information for positioning (e.g., the location of the SE). The location information may include, for example, the location of the SE, a sequence identifier of the SE, and / or the exact time at which the SE transmits the ranging signal. The location information broadcast by each SE (or another message broadcast by one or more SEs) may include the TOA at which the SE detects the ranging signal from other SEs. The location information broadcast from each SE may be, for example, broadcast in a licensed spectrum for vehicle-to-vehicle (V2V) messages, such as a radio resource control (RRC) in an intelligent transportation system (ITS) spectrum or a proximity-based service (ProSe) directional communication (PC5) signaling protocol stack (PC5-S), for example, within a specific time window. For example, the location information may be broadcast within 10-20ms to minimize the size of the buffer required by the target UE 102. The location information may be broadcast in a spectrum different from that used for ranging signals, thereby avoiding interference between ranging signals and location information.

[0045] The target UE 102 receives the ranging signal broadcasted in sequence from each SE 104-1, 104-2 and 106 in the group of SEs. The target UE 102 is configured to receive the location information broadcasted respectively from each SE 104-1, 104-2 and 106, which can be broadcasted by each SE after (or before) the SE transmits its ranging signal. The target UE 102 can use the received location information for each SE to analyze the ranging signal received from the corresponding SE. For example, the target UE 102 can use the transmission time of the ranging signal indicated in the received location information and the measured reception time of the ranging signal to determine the flight time of the ranging signal. The flight time can then be converted into a distance (spacing) to the SE, for example, by dividing the flight time by the speed of light. If the transmission time of the ranging signal is not provided, the target UE 102 can determine the transmission time based on the sequence identifier of the SE and the known frequency of the ranging signal transmission and the first transmission time of the ranging signal, which can be provided by the beginning SE 104-1. Once the distance to the SE is determined, the target UE 102 can use the location of the SE indicated in the received location information and the determined distance to determine the location of the target UE 102, for example, using triangulation. The target UE 102 can further refine its location by combining its relative position using the ranging signal and the determined SPS position.

[0046] In some implementations, the target UE 102 may use the TOA measured by the SE together with its own TOA measurement to generate a received signal time difference (RSTD) measurement. For example, SE 104-2 may provide, for example, in location information or in a separate message, a TOA measurement of a ranging signal received by SE 104-2 from SE 104-1, and similarly, SE 106 may provide a TOA measurement of a ranging signal received by SE 106 from SE 104-1. The target UE 102 may use its own TOA measurement to generate an RSTD measurement for the ranging signal from SE 104-1. The position of the target UE 102 may therefore be determined using RSTD, for example, using an observed time difference of arrival (OTDOA). In order to use RSTD for precise positioning, four or more SEs may typically be used.

[0047] Figure 3 An embodiment of a call flow 300 for a location determination session with a UE 102 and a set of SEs including the beginning SEs 104-1 and 104-2 and SE 106 is illustrated. It should be appreciated that the target UE 102 may communicate with one or more SEs prior to the start of the location determination session.

[0048] As shown, in stage 1, the target UE 102 may send a request for a ranging signal to a SE, such as the leading SE 104-1, which may be a request for a periodic ranging signal or a request for an on-demand ranging signal.

[0049] In phase 2, the leading SE 104-1 forms a group of SEs including SE 104-2 and SE 106, and provides a request for a ranging signal to the SEs in the established group. For example, the leading SE 104-1 can be determined as the leading SE in the group based on previous contact with the target UE 102 (in phase 1) or other mechanisms, for example, based on the capabilities of SE 104-1. The leading SE 104-1 can provide information that the SEs can use to identify their sequence numbers in the group of SEs, for example, the leading SE 104-1 can assign a sequence number to each SE, or can provide information that each SE can use to determine its sequence number, for example, the leading SE 104-1 can provide the number of SEs in the group, and each SE can determine its sequence number as a layer 2 identifier (L2 ID) mod#SE. In some implementations, the group can include one SE, for example, the leading SE 104-1.

[0050] In stage 3, the head SE 104-1 may check the availability of channels on the spectrum to be used for ranging signals, for example, by detecting the energy levels of different channels in the spectrum to determine whether the channels are occupied or idle. The head SE 104-1 generates ranging signals, for example, using unoccupied or idle channels, and generates a preamble that identifies used channels and reserves used channels during sequential broadcasts of ranging signals from the SE.

[0051] In phase 4, the leading SE 104-1 broadcasts a ranging signal, which is received by the target UE 102 and the other SEs in the group of SEs, namely SE 104-2 and SE 106. The ranging signal can be, for example, a PRS or SRS signal, can be transmitted on an unlicensed spectrum, and can be a wideband signal using a continuous or non-contiguous channel. The target UE 102 measures the TOA of the ranging signal from the leading SE 104-1.

[0052] In stage 5, the next SE 104-2 in the group of SEs determines an available channel in the spectrum, for example, by detecting the channel used or identified in the preamble of the ranging signal received in stage 4. The SE 104-2 generates a ranging signal using the available channel.

[0053] In stage 6, SE 104-2 broadcasts a ranging signal, which is received by the target UE 102 and other SEs in the group of SEs (i.e., SE 106). The ranging signal can be, for example, a PRS or SRS signal, can be transmitted on an unlicensed spectrum, and can be a wideband signal using a continuous or non-contiguous channel. The target UE 102 measures the TOA of the ranging signal from SE 104-2.

[0054] In stage 7, the next SE 106 in the group of SEs determines an available channel in the spectrum, for example, by detecting the channel used or identified in the preamble of the ranging signal received in stage 4 or stage 6. The SE 106 generates a ranging signal using the available channel.

[0055] In stage 8, SE 106 broadcasts a ranging signal which is received by target UE 102 and any other SEs ( Figure 3 The ranging signal may be, for example, a PRS or SRS signal, may be transmitted on an unlicensed spectrum, and may be a broadband signal using a continuous or non-continuous channel. The target UE 102 measures the TOA of the ranging signal from the SE 106.

[0056] At stage 9, initially SE 104-1 broadcasts location information for SE 104-1 that is received by target UE 102. The location information may be transmitted on a licensed spectrum, such as an ITS spectrum. The location information may include, for example, the location of SE 104-1, a sequence identifier of SE 104-1, and the exact time when SE 104-1 transmitted the ranging signal.

[0057] In stage 10, SE 104-2 broadcasts location information for SE 104-2 that is received by target UE 102. The location information may be transmitted on a licensed spectrum, such as an ITS spectrum. The location information may include, for example, the location of SE 104-2, a sequence identifier of SE 104-2, the exact time when SE 104-2 transmitted the ranging signal. The location information may further include the TOA of the ranging signal from the leading SE 104-1 detected by SE 104-2 in stage 4.

[0058] In phase 11, SE 106 broadcasts location information for SE 106 that is received by target UE 102. The location information may be transmitted on a licensed spectrum, such as an ITS spectrum. The location information may include, for example, the location of SE 106, a sequence identifier of SE 106, the exact time when SE 106 transmitted the ranging signal. The location information may further include the TOA of the ranging signal from the leading SE 104-1 and / or SE 104-2 detected by SE 106 in phase 4 and / or phase 6.

[0059] In stage 12, the target UE 102 determines the distance to each SE 104-1, 104-2, and 106. For example, the target UE 102 may use the TOA of the ranging signal measured in stages 4, 6, and 8 and the transmission time received in the location information in stages 9, 10, and 11 to determine the flight time of each ranging signal, which may be converted into the distance (spacing) to each SE 104-1, 104-2, and 106. In some implementations, the TOA measurement of the target UE 102 and the transmission time from the SE may be synchronized, for example, using an RTT method, or may be estimated based on a Kalman filter. The target UE 102 may use the sequence identifier provided in the location information of stages 9, 10, and 11, and the frequency of the ranging signal transmission from the beginning SE 104-1 and the transmission time of the ranging signal (which may be included in the preamble of the ranging signal in stage 4 or in the location information received in stage 9) to determine the transmission time of each ranging signal from SEs 104-2 and 106. In another implementation, the target UE 102 may use the TOA of the ranging signal measured by the SE provided in the location information of stages 9, 10, and 11, and the TOA measured by the target UE 102 in stages 4, 6, and 8 to determine the relative ranging signal, such as RSTD.

[0060] In stage 13, the target UE 102 may use the distance determined in stage 12 and the positions of the SEs 104-1, 104-2, and 106 received in the location information of stages 9, 10, and 11 to estimate the position of the target UE 102, for example, using triangulation or other appropriate techniques. In some implementations, the target 102 may use the distance determined in stage 12 and the positions of the SEs 104-1, 104-2, and 106 received in the location information of stages 9, 10, and 11 to estimate the relative position of the target UE 102, which may be combined with the measured SPS position to derive the precise position of the target UE 102.

[0061] Figure 4 is a diagram of a user equipment (UE) (such as Figure 1 , 2 3 and 4. As shown in block 402, a ranging signal broadcast by each of a plurality of entities in a wireless network is received, for example, Figure 3 At block 404, a message having location information broadcast from each of a plurality of entities is received, e.g., Figure 3For example, the message with the location information may be broadcast at a different time than the ranging signal. At block 406, the distance to each entity is determined using the ranging signal received from each entity and the location information received from each entity, such as Figure 3 At block 408, the location of the user device is determined based on the distance to each entity and the known location of each entity, e.g., Figure 3 The stage 13 shown is discussed.

[0062] In one implementation, the plurality of entities includes clusters of entities that broadcast ranging signals sequentially, e.g. Figure 3 The ranging signals broadcast sequentially may be broadcast without time overlap and using the same set of channels. The first ranging signal in the sequentially broadcast ranging signals may include an identification of the set of channels in a preamble determined by a first entity in the entity cluster.

[0063] In one implementation, each ranging signal broadcast by each entity is a wideband waveform comprising multiple channels. The multiple channels may be contiguous, or the multiple channels may not be contiguous.

[0064] In one implementation, each entity of the plurality of entities includes one of a roadside unit or a vehicle.

[0065] In one implementation, each message with location information is received from each entity in an Intelligent Transport System (ITS) spectrum.

[0066] In one implementation, the location information broadcast by the entity may include at least one of: a known location of the entity, a sequence identifier indicating the location of the entity in a sequentially broadcast ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof. In one implementation, for each entity, determining the distance to the entity may use a time at which the ranging signal was received from the entity and a time at which the entity broadcast the ranging signal received in the location information from the entity. In one implementation, for each entity, determining the time at which the entity broadcast the ranging signal may use a sequence identifier received in the location information from the entity, and determining the distance to the entity uses a time at which the ranging signal was received from the entity and a time at which the entity broadcast the ranging signal determined using the sequence identifier.

[0067] Figure 5 is a diagram that supports entities in a wireless network such as Figure 1 , 2 and 3 shown in the beginning SE 104-1 or SE104-2, 106) executed by the user equipment (UE) (such as Figure 1 ,2 3 and 4. As shown in block 502, an available portion of a wireless spectrum is determined by an entity, where the entity is one of a plurality of ranging sources of a UE, such as Figure 3 At block 504, a ranging signal is generated on an available portion of the wireless spectrum, such as Figure 3 In block 506, a ranging signal is broadcast to be received by the UE, for example, Figure 3 At block 508, a message is broadcast having location information associated with the ranging signal, e.g. Figure 3 The illustrated stages 9, 10 and 11 are discussed. The message with the location information may be broadcast at a different time than the ranging signal.

[0068] In one implementation, the ranging signal is a broadband waveform comprising multiple channels. The multiple channels may be continuous, or the multiple channels may not be continuous.

[0069] In one implementation, the multiple ranging sources of the UE include a ranging source cluster that broadcasts ranging signals sequentially. In one implementation, the ranging signals broadcast sequentially are broadcast without time overlap and using the same set of channels. In one implementation, a first ranging signal among the ranging signals broadcast sequentially includes an identifier of the set of channels in a preamble determined by a first ranging source in the ranging source cluster. For example, in one implementation, the entity may be a first ranging source among the multiple ranging sources that broadcast ranging signals sequentially. In this example, the available portion of the wireless spectrum may be determined by detecting energy levels of different channels in the wireless spectrum, such as Figure 3 In this example, the ranging signal includes generating a preamble that indicates when the sequentially broadcast ranging signal will occur. For example, in one implementation, the entity broadcasts the ranging signal after receiving the ranging signal broadcast by the ranging source that immediately precedes the entity in the sequential broadcast of the ranging signal, such as Figure 3 In this example, the available portion of the wireless spectrum is determined by examining the waveform or preamble of the ranging signal from the previous ranging source, e.g. Figure 3 Stages 5 and 7 are shown.

[0070] In one implementation, a message with location information associated with a ranging signal may be broadcast in an Intelligent Transport System (ITS) spectrum.

[0071] In one implementation, the location information may include at least one of: a location of the entity, a sequence identifier indicating a location of the entity among a plurality of ranging sources of the UE, a time when the entity broadcasts a ranging signal, or a combination thereof.

[0072] In one implementation, the entity may be a roadside unit or a vehicle.

[0073] Figure 6 is a diagram illustrating an example of a hardware implementation of a UE 600 capable of performing positioning using sequentially broadcast ranging signals as discussed herein. For example, the UE 600 may be Figure 1 , 2 , and the target UE 102 shown in FIG. 3, and may be part of a vehicle or a pedestrian. The UE 600 includes a wireless wide area network (WWAN) transceiver 620, which includes a transmitter and a receiver, such as a cellular transceiver, which is configured to receive a PRS from a base station or a SRS type ranging signal from other UEs, for example, in a vehicle or on a pedestrian in a wireless network. The WWAN transceiver 620 may also be configured to directly communicate wirelessly with one or more ranging source entities (SEs), such as roadside units and vehicles, and, for example, receive ranging signals and broadcast location information broadcast in sequence using wireless communications under IEEE 802.11p on the 5.9 GHz ITS band or other appropriate short-range wireless communications. The UE 600 may further include a wireless local area network (WLAN) transceiver 710, which includes a transmitter and a receiver, and may also be used to directly communicate wirelessly with other entities, and in some embodiments, wirelessly communicate with ranging source entities. UE 600 may further include an SPS receiver 630, with which SPS signals from SPS satellites (e.g., GPS or GNSS) may be received. UE 600 may include additional features, such as a user interface 640, which may include, for example, a display, a keypad, or other input device, such as a virtual keypad on a display, via which a user may interact with UE 600.

[0074] UE 600 also includes one or more processors 650 and memory 660, which may be coupled together via bus 602. The one or more processors 650 and other components of UE 600 may similarly be coupled together via bus 602 (a single bus), or may be directly connected together or coupled using a combination of the foregoing. Memory 660 may contain executable code or software instructions that, when executed by one or more processors 650, cause one or more processors 650 to operate as a special-purpose computer programmed to perform the techniques disclosed herein. Figure 6As shown, the memory 660 may include one or more components or modules that can be implemented by one or more processors 650 to perform the methods described herein. Although the components or modules are shown as software in the memory 660 that can be executed by one or more processors 650, it should be understood that the components or modules can be dedicated hardware in or outside the one or more processors 650.

[0075] The memory 660 may include a ranging signal module 662, which, when implemented by the one or more processors 650, configures the one or more processors 650 to cause the WWAN transceiver 620 to directly receive ranging signals broadcast sequentially from a group of SEs and measure the TOA of each ranging signal from each SE, e.g., Figure 3 Stages 4, 6 and 8 and Figure 4 As discussed in block 402 of FIG.

[0076] The memory 660 may further include a location information module 664 that, when implemented by the one or more processors 650, configures the one or more processors 650 to cause the WWAN transceiver 620 to directly receive a message having location information broadcast from each of the plurality of entities, such as Figure 3 Stages 9, 10 and 11 and Figure 4 In some implementations, the location information can be broadcast on a spectrum (e.g., a licensed spectrum) that is different from the spectrum used for the ranging signal (e.g., an unlicensed spectrum), although in some implementations, the location information and the ranging signal can be broadcast on the same spectrum. The location information can include, for example, at least one of the following: a location of the entity, a sequence identifier indicating a position of the entity in the sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof.

[0077] The memory 660 may further include a location determination module 668 that, when implemented by the one or more processors 650, configures the one or more processors 650 to estimate the location of the UE 600. For example, the location determination module 668 may include a ranging module 670 that, when implemented by the one or more processors 650, configures the one or more processors 650 to determine the distance to each entity using the ranging signal received from each entity and the location information received from each entity, e.g., as in Figure 3 Stage 12 and Figure 4For example, the distance may be determined using a time at which a ranging signal is received from an entity and a time at which the entity, received in location information from the entity, broadcast the ranging signal. In another example, the distance may be determined by determining a time at which the entity broadcasts the ranging signal using a sequence identifier received in location information from the entity, and then determining the distance to the entity using a time at which a ranging signal is received from the entity and a time at which the entity broadcasts the ranging signal determined using the sequence identifier.

[0078] The location determination module 668 may also include a positioning module 672, which, when implemented by the one or more processors 650, configures the one or more processors 650 to determine the location of the user device 600 based on the distance to each entity and the known location of each entity, such as in Figure 3 Stage 13 and Figure 4 For example, the positioning module 672 can configure the one or more processors 650 to determine the location of the user device 600 using triangulation based on the distances to the entities and their locations received in the location information. The positioning module 672 can further configure the one or more processors 650 to determine the location of the user device 600 using the SPS signals 630 and the distances to the entities and their locations received in the location information.

[0079] Additionally, the memory 660 may further include a transmit time module 666 that, when implemented by the one or more processors 650, configures the one or more processors 650 to use a sequence identifier received in the location information from the entity to determine a time at which the entity broadcasts the ranging signal, e.g. Figure 3 This is discussed in Stage 12 of .

[0080] The methods described herein can be implemented by various means depending on the application. For example, the methods can be implemented in hardware, firmware, software, or any combination thereof. For hardware implementations, one or more processors 650 can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0081] For implementations of UE 600 involving firmware and / or software, the methods may be implemented with modules (e.g., procedures, functions, etc.) that perform the individual functions described herein. Any machine-readable medium that tangibly embodies instructions may be used to implement the methods described herein. For example, software codes may be stored in a memory (e.g., memory 660) and executed by one or more processors 650 so that one or more processors 650 operate as a special-purpose computer programmed to perform the techniques disclosed herein. The memory may be implemented within one or more processors 650, or external to one or more processors 650. As used herein, the term "memory" refers to any type of long-term, short-term, volatile, non-volatile, or other memory, and is not limited to any particular type of memory or number of memories, or the type of medium storing the memory.

[0082] If implemented in firmware and / or software, the functions performed by the UE 600 may be stored as one or more instructions or codes on a non-transitory computer-readable storage medium such as the memory 660. Examples of storage media include computer-readable media encoded with data structures and computer-readable media encoded with computer programs. Computer-readable media include physical computer storage media. Storage media may be any available media that can be accessed by a computer. As an example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, semiconductor storage or other storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer; as used herein, disks and optical disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks, where disks typically reproduce data magnetically, and optical disks reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0083] In addition to being stored on a computer-readable storage medium, instructions and / or data for UE 600 may be provided as a signal on a transmission medium included in the communication device. For example, a communication device including part or all of UE 600 may include a transceiver having a signal indicating instructions and data. Instructions and data are stored on a non-transitory computer-readable medium, such as a memory 660, and are configured so that one or more processors 650 operate as a dedicated computer programmed to perform the technology disclosed herein. That is, the communication device includes a transmission medium having a signal indicating information to perform the disclosed functions. At a first time, the transmission medium included in the communication device may include a first portion of information to perform the disclosed functions, and at a second time, the transmission medium included in the communication device may include a second portion of information to perform the disclosed functions.

[0084] Thus, a user device such as UE 600 may include means for receiving ranging signals broadcast by each of a plurality of entities in a wireless network, which means may be, for example, a WWAN transceiver 620 and one or more processors 650 having dedicated hardware or implementing executable code or software instructions in memory 660, such as a ranging signal module 662. Means for receiving a message with location information broadcast from each of the plurality of entities may be, for example, a WWAN transceiver 620 and one or more processors 650 having dedicated hardware or implementing executable code or software instructions in memory 660, such as a location information module 664. Means for determining a distance to each entity using the ranging signals received from each entity and the location information received from each entity may be, for example, one or more processors 650 having dedicated hardware or implementing executable code or software instructions in memory 660, such as a ranging module 670. Means for determining the location of the user device based on the distance to each entity and the known location of each entity may be, for example, one or more processors 650 having dedicated hardware or implementing executable code or software instructions in memory 660 , such as a positioning module 672 .

[0085] The user equipment may further include means, such as the transmit time module 666, for determining a time at which the entity broadcasts the ranging signal using the sequence identifier received in the location information from the entity.

[0086] Figure 7is a diagram illustrating an example of a hardware implementation of a ranging source entity (SE) 700 that is capable of supporting location determination of a user equipment (UE) using sequentially broadcast ranging signals, as discussed herein. For example, the SE 700 may be a stationary entity, such as a roadside unit, but may alternatively be a non-stationary entity with a known location, such as a vehicle. The SE 700 includes a wireless wide area network (WWAN) transceiver 720, the transceiver including a transmitter and a receiver, such as a cellular transceiver, configured to wirelessly communicate directly with a target UE and broadcast ranging signals and location information to the target UE, for example, using wireless communications under IEEE 802.11p or other appropriate short-range wireless communications over the 5.9 GHz ITS band. The SE 700 may further include a wireless local area network (WLAN) transceiver 710, which includes a transmitter and a receiver and may also be used to wirelessly communicate directly with other entities, and in some embodiments, with the UE. The SE 700 may further include an SPS receiver 730 , by which an SPS signal from an SPS satellite may be received and used to determine the position of the SE 700 .

[0087] The SE 700 also includes one or more processors 740 and memory 750, which may be coupled together with the bus 702. The one or more processors 740 and other components of the SE 700 may similarly be coupled together via the bus 702 (a separate bus), or may be directly connected together or coupled using a combination of the foregoing. The memory 750 may contain executable code or software instructions that, when executed by the one or more processors 740, cause the one or more processors 740 to operate as a special-purpose computer programmed to perform the techniques disclosed herein. Figure 7 As shown, the memory 750 may include one or more components or modules that can be implemented by one or more processors 740 to perform the methods described herein. Although the components or modules are shown as software in the memory 750 that can be executed by one or more processors 740, it should be understood that the components or modules can be dedicated hardware in one or more processors 740 or outside the processor.

[0088] The memory 750 may include a channel availability module 752 that, when implemented by the one or more processors 740, configures the one or more processors 740 to use the WWAN transceiver 720 to determine an available portion of a wireless spectrum by an entity that is one of a plurality of ranging sources of the UE, such as Figure 3 Phases 3, 5 and 7 and Figure 5For example, the available portion of the wireless spectrum may be determined by detecting the energy levels of different channels in the wireless spectrum received by the WWAN transceiver 720. In another example, the available portion of the wireless spectrum may be determined by examining the waveform or preamble of the ranging signal from the previous ranging source.

[0089] The memory 750 may include a ranging signal generation module 754 that, when implemented by the one or more processors 740, configures the one or more processors 740 to generate a ranging signal on an available portion of the wireless spectrum, such as Figure 3 Phases 3, 5 and 7 and Figure 5 The ranging signal may be a broadband waveform having multiple channels, which may be continuous or discontinuous. The one or more processors 740 may be configured to generate the ranging signal to include a preamble indicating when sequentially broadcast ranging signals will occur, for example, as in Figure 3 This is discussed in Phase 3 of this document.

[0090] The memory 750 may include a ranging signal transmission module 756 that, when implemented by the one or more processors 740, configures the one or more processors 740 to use the WWAN transceiver 720 to broadcast a ranging signal to be received by the UE, e.g., Figure 3 Stages 4, 6 and 8 and Figure 5 For example, the ranging signal may be broadcast on an unlicensed spectrum. The broadcast of the ranging signal may be part of a sequential broadcast of the ranging signal by a plurality of SEs in a group of SEs, wherein the ranging signal is broadcast after receiving a ranging signal broadcast by a ranging source that immediately precedes the entity in the sequential broadcast of the ranging signal.

[0091] The memory 750 may include a location information transmission module 758 that, when implemented by the one or more processors 740, configures the one or more processors 740 to use the WWAN transceiver 720 to broadcast a message having location information associated with the ranging signal, such as in Figure 3 Stages 9, 10 and 11 and Figure 5 The location information may be broadcast in an Intelligent Transport System (ITS) spectrum, for example. The location information may include at least one of: a location of an entity, a sequence identifier indicating a position of the entity among a plurality of ranging sources of the UE, a time at which the entity broadcasts a ranging signal, or a combination thereof.

[0092] The methods described herein can be implemented by various means depending on the application. For example, the methods can be implemented in hardware, firmware, software, or any combination thereof. For hardware implementations, one or more processors 740 can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0093] For implementations of SE 700 involving firmware and / or software, the methods may be implemented with modules (e.g., programs, functions, etc.) that perform the individual functions described herein. Any machine-readable medium that tangibly embodies instructions may be used to implement the methods described herein. For example, software code may be stored in a memory (e.g., memory 750) and executed by one or more processors 740 so that one or more processors 740 operate as a special-purpose computer programmed to perform the techniques disclosed herein. The memory may be implemented within one or more processors 740, or external to one or more processors 740. As used herein, the term "memory" refers to any type of long-term, short-term, volatile, non-volatile, or other memory, and is not limited to any particular type of memory or number of memories, or the type of medium in which the memory is stored.

[0094] If implemented in firmware and / or software, the functions performed by SE 700 may be stored as one or more instructions or codes on a non-transitory computer-readable storage medium such as memory 750. Embodiments of storage media include computer-readable media encoded with data structures and computer-readable media encoded with computer programs. Computer-readable media include physical computer storage media. Storage media may be any available media that can be accessed by a computer. As an example and not a limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, semiconductor storage or other storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer; as used herein, disks and optical disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks, where disks typically reproduce data magnetically, while optical disks reproduce data optically with lasers. Combinations of the above should also be included in the range of computer-readable media.

[0095] In addition to being stored on a computer-readable storage medium, instructions and / or data for SE 700 may be provided as signals on a transmission medium included in a communication device. For example, a communication device including part or all of SE 700 may include a transceiver having signals indicating instructions and data. Instructions and data are stored on a non-transitory computer-readable medium, such as a memory 750, and are configured such that one or more processors 740 operate as a special-purpose computer programmed to perform the techniques disclosed herein. That is, the communication device includes a transmission medium having a signal indicating information to perform the disclosed functions. At a first time, the transmission medium included in the communication device may include a first portion of information to perform the disclosed functions, and at a second time, the transmission medium included in the communication device may include a second portion of information to perform the disclosed functions.

[0096] Thus, a SE, such as SE 700, may include means for determining an available portion of a wireless spectrum by an entity, wherein the entity is one of a plurality of ranging sources for a UE, such as a WWAN transceiver 720 and one or more processors 740 having dedicated hardware or implementing executable code or software instructions in memory 750, such as a channel availability module 752. Means for generating a ranging signal on the available portion of the wireless spectrum may be, for example, one or more processors 740 having dedicated hardware or implementing executable code or software instructions in memory 750, such as a ranging signal generation module 754. Means for broadcasting a ranging signal to be received by a UE may be, for example, a WWAN transceiver 720 and one or more processors 740 having dedicated hardware or implementing executable code or software instructions in memory 750, such as a ranging signal broadcast module 756. Means for broadcasting a message having location information associated with a ranging signal may be, for example, the WWAN transceiver 720 and one or more processors 740 having dedicated hardware or implementing executable code or software instructions in memory 750, such as a location information broadcast module 758.

[0097] Throughout this specification, references to "one example," "example," "some examples," or "exemplary implementations" mean that a particular feature, structure, or characteristic described in conjunction with the feature and / or example may be included in at least one feature and / or embodiment of the claimed subject matter. Thus, the phrases "in one example," "example," "some examples," or "in some implementations," or other similar phrases, appearing throughout this specification are not necessarily all referring to the same features, examples, and / or limitations. Furthermore, particular features, structures, or characteristics may be combined in one or more examples and / or features.

[0098] Some parts of the detailed description included herein are presented according to the algorithm or symbolic representation of the operation of the binary digital signal stored in the memory of a specific device or a special computing device or platform. In the context of this particular specification, the term specific device, etc. includes a general-purpose computer, which once programmed, performs specific operations according to instructions from the program software. Algorithmic description or symbolic representation is an embodiment of the technology used by ordinary technicians in signal processing or related fields to convey the essence of their work to other technicians in the field. Here, the algorithm is generally considered to be a self-consistent sequence of operations or similar signal processing that leads to a desired result. In this case, the operation or processing involves the physical manipulation of physical quantities. Generally, although not necessarily, such quantities can take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared or otherwise manipulated. It has been proven that sometimes, mainly for general reasons, it is convenient to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numbers, etc. However, it should be understood that all of these or similar terms are associated with appropriate physical quantities and are merely convenient labels. Unless otherwise specified, it is apparent from the discussion herein that it should be understood that throughout this specification, discussions using terms such as "processing," "computing," "calculating," "determining," etc. refer to the actions or processes of a specific apparatus, such as a special purpose computer, a special purpose computing device, or a similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer or a similar special purpose electronic computing device is capable of manipulating or transforming signals, typically represented as physical electronic or magnetic quantities within a memory, register, or other information storage device, transmission device, or display device of the special purpose computer or a similar special purpose electronic computing device.

[0099] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will appreciate that the claimed subject matter may be practiced without these specific details. In other cases, methods and apparatus known to those of ordinary skill in the art have not been described in detail in order to avoid obscuring the claimed subject matter.

[0100] As used herein, the terms "and," "or," and "and / or" may include multiple meanings, which are also expected to depend at least in part on the context in which such terms are used. In general, "or," if used with a list of associations, such as A, B, or C, is intended to mean A, B, and C (used herein in an inclusive sense) as well as A, B, or C (used herein in an exclusive sense). Additionally, as used herein, the term "one or more" may be used to describe any feature, structure, or characteristic in the singular, or may be used to describe a plurality of features, structures, or characteristics, or some other combination thereof. It should be noted, however, that this is merely an illustrative embodiment, and claimed subject matter is not limited to this embodiment.

[0101] While there has been shown and described what are presently considered to be exemplary features, it will be appreciated by those skilled in the art that various other modifications may be made, and equivalents may be substituted, without departing from the claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of the claimed subject matter without departing from the central concept described herein.

[0102] Therefore, it is intended that the claimed subject matter not be limited to the particular embodiments disclosed, but that such claimed subject matter may also include all aspects falling within the scope of the appended claims and equivalents thereof.

Claims

1. A method for performing location determination by a user equipment (UE), the method comprising: receiving a ranging signal broadcasted by each of a plurality of entities in a wireless network, wherein: The plurality of entities comprises a cluster of entities broadcasting ranging signals sequentially, wherein the ranging signals broadcast sequentially are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the ranging signals broadcast sequentially comprises in a preamble an identification of the set of channels determined by a first entity of the cluster of entities; receiving a message having location information broadcast from each of the plurality of entities; determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and The location of the user equipment is determined based on the distance to each entity and the known location of each entity.

2. The method according to claim 1, wherein: Each ranging signal broadcast by each entity is a wideband waveform comprising multiple channels.

3. The method according to claim 2, wherein: The plurality of channels are contiguous.

4. The method according to claim 2, wherein: The plurality of channels are non-contiguous.

5. The method according to claim 1, wherein: Each entity of the plurality of entities includes a roadside unit or a vehicle.

6. The method according to claim 1, wherein: Each message with the location information is received from each entity in an Intelligent Transport System (ITS) spectrum.

7. The method according to claim 1, wherein: The location information broadcast by an entity includes at least one of: a known location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof.

8. The method according to claim 7, wherein: For each entity, determining the distance to the entity uses a time at which a ranging signal was received from the entity and the time at which the entity broadcast the ranging signal received in the location information from the entity.

9. The method of claim 7, further comprising, for each entity, determining the time at which the entity broadcast the ranging signal using the sequence identifier received in the location information from the entity, and determining the distance to the entity using the time at which the ranging signal was received from the entity and the time at which the entity broadcast the ranging signal determined using the sequence identifier.

10. A user equipment (UE), configured to support location determination, comprising: a wireless transceiver configured to receive broadcast signals from entities in the wireless network; at least one memory; as well as at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to: receiving a ranging signal broadcasted by each of a plurality of entities in a wireless network, wherein: The plurality of entities comprises a cluster of entities broadcasting ranging signals sequentially, wherein the ranging signals broadcast sequentially are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the ranging signals broadcast sequentially comprises in a preamble an identification of the set of channels determined by a first entity of the cluster of entities; receiving a message having location information broadcast from each of the plurality of entities; determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and The location of the user equipment is determined based on the distance to each entity and the known location of each entity.

11. The UE according to claim 10, wherein: Each ranging signal broadcast by each entity is a wideband waveform comprising multiple channels.

12. The UE according to claim 11, wherein: The plurality of channels are contiguous.

13. The UE according to claim 11, wherein: The plurality of channels are non-contiguous.

14. The UE according to claim 10, wherein: Each entity of the plurality of entities includes a roadside unit or a vehicle.

15. The UE according to claim 10, wherein: Each message with the location information is received from each entity in an Intelligent Transport System (ITS) spectrum.

16. The UE according to claim 10, wherein: The location information broadcast by an entity includes at least one of: the known location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof.

17. The UE according to claim 16, wherein: For each entity, the at least one processor is configured to determine the distance to the entity using a time at which a ranging signal was received from the entity and the time at which the entity broadcast the ranging signal received in the location information from the entity.

18. The UE of claim 16, further comprising, for each entity, the at least one processor being further configured to determine the time at which the entity broadcasts the ranging signal using the sequence identifier received in the location information from the entity, and the at least one processor being configured to determine the distance to the entity using the time at which the ranging signal is received from the entity and the time at which the entity broadcasts the ranging signal determined using the sequence identifier.

19. A user equipment (UE) configured to support location determination, comprising: means for receiving a ranging signal broadcast by each of a plurality of entities in a wireless network, wherein: The plurality of entities comprises a cluster of entities broadcasting ranging signals sequentially, wherein the ranging signals broadcast sequentially are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the ranging signals broadcast sequentially comprises in a preamble an identification of the set of channels determined by a first entity of the cluster of entities; means for receiving a message having location information broadcast from each of the plurality of entities; means for determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and Means for determining a location of the user equipment based on the distance to each entity and a known location of each entity.

20. The UE according to claim 19, wherein: Each ranging signal broadcast by each entity is a wideband waveform comprising multiple channels.

21. The UE according to claim 19, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof, wherein for each entity, the means for determining the distance to the entity uses a time at which a ranging signal was received from the entity and the time at which the entity broadcast the ranging signal received in the location information from the entity.

22. The UE according to claim 19, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof, wherein the UE further includes means for determining the time at which the entity broadcast the ranging signal using the sequence identifier received in the location information from the entity, and the means for determining the distance to the entity uses the time at which the ranging signal was received from the entity and the time at which the entity broadcast the ranging signal determined using the sequence identifier.

23. A non-transitory computer-readable medium having one or more computer-executable instructions stored thereon, which, when executed by one or more processors of a user equipment (UE) for performing location determination, cause the one or more processors to perform a method comprising: receiving a ranging signal broadcasted by each of a plurality of entities in a wireless network, wherein: The plurality of entities comprises a cluster of entities broadcasting ranging signals sequentially, wherein the ranging signals broadcast sequentially are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the ranging signals broadcast sequentially comprises in a preamble an identification of the set of channels determined by a first entity of the cluster of entities; receiving a message having location information broadcast from each of the plurality of entities; determining a distance to each entity using the ranging signal received from each entity and the location information received from each entity; and The location of the user equipment is determined based on the distance to each entity and the known location of each entity.

24. The non-transitory computer readable medium of claim 23, wherein: Each ranging signal broadcast by each entity is a wideband waveform comprising multiple channels.

25. The non-transitory computer readable medium of claim 23, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof, wherein for each entity, the program code for determining the distance to the entity uses a time at which a ranging signal was received from the entity and the time at which the entity broadcast the ranging signal received in the location information from the entity.

26. The non-transitory computer readable medium of claim 23, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity in a sequential broadcast of the ranging signal, a time at which the entity broadcast the ranging signal, or a combination thereof, wherein for each entity, the non-transitory computer-readable medium further includes program code for determining the time at which the entity broadcast the ranging signal using the sequence identifier received in the location information from the entity, and program code for determining a distance to the entity using the time at which the ranging signal was received from the entity and the time at which the entity broadcast the ranging signal determined using the sequence identifier.

27. A method performed by an entity in a wireless network to support location determination of a user equipment (UE), the method comprising: determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE, wherein: The plurality of ranging sources for the UE comprises a cluster of ranging sources that sequentially broadcast ranging signals, wherein the sequentially broadcast ranging signals are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal in the sequentially broadcast ranging signals comprises in a preamble an identification of the set of channels determined by the first ranging source in the cluster of ranging sources; generating a ranging signal over said available portion of said wireless spectrum; broadcasting the ranging signal to be received by the UE; and A message is broadcast having location information associated with the ranging signal.

28. The method according to claim 27, wherein: The ranging signal is a broadband waveform containing multiple channels.

29. The method according to claim 28, wherein: The plurality of channels are contiguous.

30. The method of claim 28, wherein: The plurality of channels are non-contiguous.

31. The method of claim 27, wherein: The entity is a first ranging source of the plurality of ranging sources that sequentially broadcast ranging signals.

32. The method according to claim 31, wherein: Determining the usable portion of the wireless spectrum includes detecting energy levels of different channels in the wireless spectrum.

33. The method according to claim 31, wherein: Generating the ranging signal includes generating a preamble that indicates a time when the sequentially broadcast ranging signal will occur.

34. The method of claim 27, wherein: The entity broadcasts the ranging signal after receiving a ranging signal broadcast by a ranging source that immediately precedes the entity in the sequential broadcasting of the ranging signal.

35. The method of claim 34, wherein: Determining the available portion of the wireless spectrum includes examining a waveform or preamble of a ranging signal from a previous ranging source.

36. The method of claim 27, wherein: The message with the location information associated with the ranging signal is broadcast in an Intelligent Transport System (ITS) spectrum.

37. The method of claim 27, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity among the plurality of ranging sources of the UE, a time when the entity broadcasts the ranging signal, or a combination thereof.

38. The method of claim 27, wherein: The entity includes a roadside unit or a vehicle.

39. An entity in a wireless network capable of supporting location determination of a user equipment (UE), comprising: a wireless transceiver configured to broadcast a signal to the UE in a wireless network; at least one memory; and at least one processor coupled to the wireless transceiver and the at least one memory, the at least one processor configured to: determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE, wherein: The plurality of ranging sources for the UE comprises a cluster of ranging sources that sequentially broadcast ranging signals, wherein the sequentially broadcast ranging signals are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the sequentially broadcast ranging signals comprises in a preamble an identification of the set of channels determined by the first ranging source in the cluster of ranging sources; generating a ranging signal over said available portion of said wireless spectrum; broadcasting the ranging signal to be received by the UE; and A message is broadcast having location information associated with the ranging signal.

40. An entity according to claim 39, wherein: The ranging signal is a broadband waveform containing multiple channels.

41. An entity according to claim 40, wherein: The plurality of channels are contiguous.

42. An entity according to claim 40, wherein: The plurality of channels are non-contiguous.

43. An entity according to claim 39, wherein: The entity is a first ranging source of the plurality of ranging sources that sequentially broadcast ranging signals.

44. An entity according to claim 43, wherein: The at least one processor is configured to determine the available portion of the wireless spectrum by being configured to detect energy levels of different channels in the wireless spectrum.

45. An entity according to claim 43, wherein: The at least one processor is configured to generate the ranging signal by being configured to generate a preamble indicating a time at which the sequentially broadcast ranging signal will occur.

46. ​​An entity according to claim 39, wherein: The entity broadcasts the ranging signal after receiving a ranging signal broadcast by a ranging source that immediately precedes the entity in the sequential broadcasting of the ranging signal.

47. An entity according to claim 46, wherein The at least one processor is configured to determine the available portion of the wireless spectrum by being configured to examine a waveform or preamble of a ranging signal from a previous ranging source.

48. An entity according to claim 39, wherein: The message with the location information associated with the ranging signal is broadcast in an Intelligent Transport System (ITS) spectrum.

49. An entity according to claim 39, wherein: The location information includes at least one of: a location of the entity, a sequence identifier indicating a position of the entity among the plurality of ranging sources of the UE, a time when the entity broadcasts the ranging signal, or a combination thereof.

50. An entity according to claim 39, wherein: The entity includes a roadside unit or a vehicle.

51. An entity in a wireless network capable of supporting location determination of a user equipment (UE), comprising: means for determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE, wherein the plurality of ranging sources for the UE comprises a cluster of ranging sources that sequentially broadcast ranging signals, wherein the sequentially broadcast ranging signals are broadcast without temporal overlap and using a same set of channels, and wherein a first ranging signal of the sequentially broadcast ranging signals comprises in a preamble an identification of the set of channels determined by the first ranging source in the cluster of ranging sources; means for generating a ranging signal over said available portion of said radio spectrum; means for broadcasting the ranging signal to be received by the UE; and Means for broadcasting a message having location information associated with said ranging signal.

52. An entity according to claim 51, wherein The entity is a first ranging source of the plurality of ranging sources that sequentially broadcast ranging signals.

53. A non-transitory computer-readable medium having one or more computer-executable instructions stored thereon, which when executed by one or more processors of an entity in a wireless network for supporting location determination of a user equipment (UE), cause the one or more processors to perform a method comprising: determining, by the entity, an available portion of a wireless spectrum, wherein the entity is one of a plurality of ranging sources for the UE, wherein: The plurality of ranging sources for the UE comprises a cluster of ranging sources that sequentially broadcast ranging signals, wherein the sequentially broadcast ranging signals are broadcast without time overlap and using a same set of channels, and wherein a first ranging signal of the sequentially broadcast ranging signals comprises in a preamble an identification of the set of channels determined by the first ranging source in the cluster of ranging sources; generating a ranging signal over said available portion of said wireless spectrum; broadcasting the ranging signal to be received by the UE; and A message is broadcast having location information associated with the ranging signal.

54. The non-transitory computer readable medium of claim 53, wherein: The entity is a first ranging source of the plurality of ranging sources that sequentially broadcast ranging signals.

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