Ultrawideband range accuracy

Techniques are provided for improving ranging accuracy of ultrawideband (UWB) devices. An example method for obtaining a distance measurement with a wireless node includes obtaining a first distance measurement using a first radio link, determining a status of a second radio link in response to the first distance measurement being less than a threshold distance, configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path, and obtaining a second distance measurement using the second radio link and the one or more transceiver parameters.

BACKGROUND

The use of wireless devices for many everyday activities is becoming common. Modern wireless devices may make use of one or more wireless communication technologies. For example, a wireless device may communicate using a short range communication technology such as Bluetooth technology, ultrawideband (UWB) technology, millimeter wave (mmWave) technology, etc. The use of short range communication technologies, such as Bluetooth, in wireless devices has become much more common in the last several years and is regularly used in retail businesses, offices, homes, cars, and public gathering places. The larger bandwidth of UWB devices may be beneficial for ranging protocols used in high security applications such as digital keys. The range accuracy associated with UWB devices may degrade in some use cases such as at long range or when the line of sight between the UWB devices is obstructed. There is a need to improve the ranging accuracy for UWB devices to support multiple use cases.

SUMMARY

An example method for obtaining a distance measurement with a wireless node according to the disclosure includes obtaining a first distance measurement using a first radio link, determining a status of a second radio link in response to the first distance measurement being less than a threshold distance, configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path, and obtaining a second distance measurement using the second radio link and the one or more transceiver parameters.

Implementations of such a method may include one or more of the following features. The first radio link may be a Bluetooth based technology. The first radio link may be a WiFi based technology. The second radio link may be a ultrawideband technology. The threshold distance may be 100 meters or less. Determining that the second radio link is utilizing the non-line of sight path may include receiving a plurality of radio frequency signals on the first radio link or the second radio link, and detecting the non-line of sight path based on the plurality of radio frequency signals. The method may further include determining a first range value based on a round trip time associated with the plurality of radio frequency signals, determining a second range value based on a received signal strength indication associated with the plurality of radio frequency signals, and detecting the non-line of sight path based at least in part on a comparison of the first range value and the second range value. Determining a channel state indication based on at least one of the plurality of radio frequency signals, and detecting the non-line of sight path based at least in part on the channel state indication. Determining a time-of-flight variance value associated with the plurality of radio frequency signals, and detecting the non-line of sight path based at least in part on the time-of-flight variance value. Comparing one or more signal measurement values obtained via the second radio link to a key performance indicator value, and configuring the one or more transceiver parameters based at least in part on a difference between the one or more signal measurement values and the key performance indicator value. Configuring the one or more transceiver parameters may include increasing a transmit output power. Configuring the one or more transceiver parameters may include decreasing a transmit packet length. Configuring the one or more transceiver parameters may include modifying a receiver antenna configuration. The wireless node may be a user equipment. The user equipment may be a digital key fob. The wireless node may be a controller in a vehicle.

An apparatus according to the disclosure includes a memory, at least one transceiver, at least one processor communicatively coupled to the memory and the at least one transceiver, and configured to obtain a first distance measurement using a first radio link, determine a status of a second radio link in response to the first distance measurement being less than a threshold distance, configure one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path, and obtain a second distance measurement using the second radio link and the one or more transceiver parameters.

Implementations of such an apparatus may include one or more of the following features. The at least one transceiver may include a Bluetooth module and the first radio link may be a Bluetooth based technology. The at least one transceiver may include a WiFi module and the first radio link may be a WiFi based technology. The at least one transceiver may include an ultrawideband module and the second radio link may be a ultrawideband technology. The threshold distance may be 100 meters or less. The at least one processor may be further configured to receive a plurality of radio frequency signals on the first radio link or the second radio link, and detect the non-line of sight path based on the plurality of radio frequency signals. The at least one processor may be further configured to determine a first range value based on a round trip time associated with the plurality of radio frequency signals, determine a second range value based on a received signal strength indication associated with the plurality of radio frequency signals, and detect the non-line of sight path based at least in part on a comparison of the first range value and the second range value. The at least one processor may be further configured to determine a channel state indication based on the plurality of radio frequency signals, and detect the non-line of sight path based at least in part on the channel state indication. The at least one processor may be further configured to determine a time-of-flight variance value associated with the plurality of radio frequency signals, and detect the non-line of sight path based at least in part on the time-of-flight variance value. The at least one processor may be further configured to compare one or more signal measurement values obtained via the second radio link to a key performance indicator value, and configure the one or more transceiver parameters based at least in part on a difference between the one or more signal measurement values and the key performance indicator value. The at least one processor may be further configured to increase a transmit power to configure the one or more transceiver parameters. The at least one processor may be further configured to decrease a transmit packet length to configure the one or more transceiver parameters. The at least one processor may be further configured to modify a receiver antenna configuration to configure the one or more transceiver parameters.

Items and/or techniques described herein may provide one or more of the following capabilities, as well as other capabilities not mentioned. Two wireless nodes may be configured to transmit and receive range measurements using different radio links. An initial range may be established using a first radio link such as Bluetooth or WiFi. A subsequent range may be measured using a second radio link when the wireless nodes are within range of the second radio link. The second radio link may be an ultrawideband (UWB) radio link. A non-line of sight (NLOS) condition may be detected based on signals received on the first or second radio links. Transmitter parameters on the second radio link may be modified based on the detection of the NLOS condition. Transmit power and/or transmit signal profiles (e.g., packet lengths) may be modified to improve the measurement results. Receiver antenna configurations may also be modified. The transceiver parameter modifications may improve the accuracy of UWB based positioning. The parameter modification may be implemented based on a desired key performance indicator. Limiting UWB signals to short range measurements may conserve battery power. Other capabilities may be provided and not every implementation according to the disclosure must provide any, let alone all, of the capabilities discussed.

DETAILED DESCRIPTION

Techniques are discussed herein for improving ranging accuracy of ultrawideband (UWB) devices. A short-range communication technology such as Bluetooth technology (BLE), UWB, or millimeter wave (mmWave) may be used for ranging applications such as digital keys and consumer asset tracking. Bluetooth technology (BLE) may also be referred to as Bluetooth low energy technology. UWB may be used for secure ranging protocols which require decimeter-level ranging accuracy as well as high security. UWB devices, with approximately 500 MHz bandwidth, may achieve decimeter-level ranging accuracy in line of sight (LOS) conditions. The low transmit power of UWB systems, however, may cause a degradation of ranging performance in non-line of sight (NLOS) conditions. For example, the accuracy of a UWB digital key may drop to half-meter accuracy due to NLOS conditions such as blocking a signal with a human body, or when the digital key is located in a closed environment such as a backpack or purse. The techniques provided herein reduce ranging fluctuations associated with UWB ranging in NLOS conditions.

A UWB capable wireless device may be configured to execute a multi-level adaptation algorithm to detect NLOS conditions and then configure one or more transceiver parameters such as transmit (Tx) power, packet length, idle time and number of receive (Rx) antennas to improve UWB ranging accuracy. In an example, the algorithm may be triggered when both a short range condition and a NLOS condition are detected. Existing algorithms may be used to determine the short range and NLOS conditions. For example, time-of-flight (ToF) measurements such as obtained with round trip time (RTT) procedures, and signal strength measurements (e.g., radio signal strength indication (RSSI) values) may be used to determine an initial range and detect a NLOS condition. Channel State Information (CSI) and ToF variations may also be used to detect NLOS conditions. In an example, a UWB ranging systems may be triggered by BLE range measurements such that UWB ranging occurs when the BLE range measurements indicate a close range. In an example, Wi-Fi range measurements may be used to detect an initial range to trigger UWB ranging. The multi-level adaptation algorithm may utilize input from other ranging techniques to modify the transceiver parameters associated with the UWB ranging. These techniques and configurations are examples, and other techniques and configurations may be used.

Referring toFIG.1, an example of a communication system100includes a UE105, a Radio Access Network (RAN)135, here a Fifth Generation (5G) Next Generation (NG) RAN (NG-RAN), and a 5G Core Network (5GC)140. The UE105may be, e.g., an IoT device, a consumer asset tracker device, a cellular telephone, digital key (e.g., key fob), or other device. A 5G network may also be referred to as a New Radio (NR) network; NG-RAN135may be referred to as a 5G RAN or as an NR RAN; and 5GC140may be referred to as an NG Core network (NGC). Standardization of an NG-RAN and 5GC is ongoing in the 3rdGeneration Partnership Project (3GPP). Accordingly, the NG-RAN135and the 5GC140may conform to current or future standards for 5G support from 3GPP. The NG-RAN135may be another type of RAN, e.g., a 3G RAN, a 4G Long Term Evolution (LTE) RAN, etc. The communication system100may utilize information from a constellation185of satellite vehicles (SVs)190,191,192,193for a Satellite Positioning System (SPS) (e.g., a Global Navigation Satellite System (GNSS)) like the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), Galileo, or Beidou or some other local or regional SPS such as the Indian Regional Navigational Satellite System (IRNSS), the European Geostationary Navigation Overlay Service (EGNOS), or the Wide Area Augmentation System (WAAS). Additional components of the communication system100are described below. The communication system100may include additional or alternative components.

As shown inFIG.1, the NG-RAN135includes NR nodeBs (gNBs)110a,110b, and a next generation eNodeB (ng-eNB)114, and the 5GC140includes an Access and Mobility Management Function (AMF)115, a Session Management Function (SMF)117, a Location Management Function (LMF)120, and a Gateway Mobile Location Center (GMLC)125. The gNBs110a,110band the ng-eNB114are communicatively coupled to each other, are each configured to bi-directionally wirelessly communicate with the UE105, and are each communicatively coupled to, and configured to bi-directionally communicate with, the AMF115. The AMF115, the SMF117, the LMF120, and the GMLC125are communicatively coupled to each other, and the GMLC is communicatively coupled to an external client130. The SMF117may serve as an initial contact point of a Service Control Function (SCF) (not shown) to create, control, and delete media sessions.

FIG.1provides a generalized illustration of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated or omitted as necessary. Specifically, although one UE105is illustrated, many UEs (e.g., hundreds, thousands, millions, etc.) may be utilized in the communication system100. Similarly, the communication system100may include a larger (or smaller) number of SVs (i.e., more or fewer than the four SVs190-193shown), gNBs110a,110b, ng-eNBs114, AMFs115, external clients130, and/or other components. The illustrated connections that connect the various components in the communication system100include data and signaling connections which may include additional (intermediary) components, direct or indirect physical and/or wireless connections, and/or additional networks. Furthermore, components may be rearranged, combined, separated, substituted, and/or omitted, depending on desired functionality.

WhileFIG.1illustrates a 5G-based network, similar network implementations and configurations may be used for other communication technologies, such as 3G, Long Term Evolution (LTE), etc. Implementations described herein (be they for 5G technology and/or for one or more other communication technologies and/or protocols) may be used to transmit (or broadcast) directional synchronization signals, receive and measure directional signals at UEs (e.g., the UE105) and/or provide location assistance to the UE105(via the GMLC125or other location server) and/or compute a location for the UE105at a location-capable device such as the UE105, the gNB110a,110b, or the LMF120based on measurement quantities received at the UE105for such directionally-transmitted signals. The gateway mobile location center (GMLC)125, the location management function (LMF)120, the access and mobility management function (AMF)115, the SMF117, the ng-eNB (eNodeB)114and the gNBs (gNodeBs)110a,110bare examples and may, in various embodiments, be replaced by or include various other location server functionality and/or base station functionality respectively.

The UE105may comprise and/or may be referred to as a device, a mobile device, a wireless device, a mobile terminal, a terminal, a mobile station (MS), a Secure User Plane Location (SUPL) Enabled Terminal (SET), or by some other name. Moreover, the UE105may correspond to a cellphone, smartphone, laptop, tablet, PDA, navigation device, Internet of Things (IoT) device, asset tracker, health monitors, security systems, smart city sensors, smart meters, digital key, or some other portable or moveable device. Typically, though not necessarily, the UE105may support wireless communication using one or more Radio Access Technologies (RATs) such as Global System for Mobile communication (GSM), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), LTE, High Rate Packet Data (HRPD), IEEE 802.11 WiFi (also referred to as Wi-Fi), Bluetooth® (BT), Worldwide Interoperability for Microwave Access (WiMAX), 5G new radio (NR) (e.g., using the NG-RAN135and the 5GC140), etc. The UE105may support wireless communication using a Wireless Local Area Network (WLAN) which may connect to other networks (e.g., the Internet) using a Digital Subscriber Line (DSL) or packet cable, for example. The use of one or more of these RATs may allow the UE105to communicate with the external client130(e.g., via elements of the 5GC140not shown inFIG.1, or possibly via the GMLC125) and/or allow the external client130to receive location information regarding the UE105(e.g., via the GMLC125).

The UE105may be configured to communicate with other entities using one or more of a variety of technologies. The UE105may be configured to connect indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. The D2D P2P links may be supported with any appropriate D2D radio access technology (RAT), such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, 5G CV2X Sidelink, 5G ProSe, and so on. One or more of a group of UEs utilizing D2D communications may be within a geographic coverage area of a Transmission/Reception Point (TRP) such as one or more of the gNBs110a,110b, and/or the ng-eNB114. Other UEs in such a group may be outside such geographic coverage areas, or may be otherwise unable to receive transmissions from a base station. Groups of UEs communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE may transmit to other UEs in the group. A TRP may facilitate scheduling of resources for D2D communications. In other cases, D2D communications may be carried out between UEs without the involvement of a TRP.

Base stations (BSs) in the NG-RAN135shown inFIG.1include NR Node Bs, referred to as the gNBs110aand110b. Pairs of the gNBs110a,110bin the NG-RAN135may be connected to one another via one or more other gNBs. Access to the 5G network is provided to the UE105via wireless communication between the UE105and one or more of the gNBs110a,110b, which may provide wireless communications access to the 5GC140on behalf of the UE105using 5G. InFIG.1, the serving gNB for the UE105is assumed to be the gNB110a, although another gNB (e.g. the gNB110b) may act as a serving gNB if the UE105moves to another location or may act as a secondary gNB to provide additional throughput and bandwidth to the UE105.

Base stations (BSs) in the NG-RAN135shown inFIG.1may include the ng-eNB114, also referred to as a next generation evolved Node B. The ng-eNB114may be connected to one or more of the gNBs110a,110bin the NG-RAN135, possibly via one or more other gNBs and/or one or more other ng-eNBs. The ng-eNB114may provide LTE wireless access and/or evolved LTE (eLTE) wireless access to the UE105. One or more of the gNBs110a,110band/or the ng-eNB114may be configured to function as positioning-only beacons which may transmit signals to assist with determining the position of the UE105but may not receive signals from the UE105or from other UEs.

The BSs, such as the gNB110a, gNB110b, ng-eNB114may each comprise one or more TRPs. For example, each sector within a cell of a BS may comprise a TRP, although multiple TRPs may share one or more components (e.g., share a processor but have separate antennas). The communication system100may include macro TRPs or the communication system100may have TRPs of different types, e.g., macro, pico, and/or femto TRPs, etc. A macro TRP may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by terminals with service subscription. A pico TRP may cover a relatively small geographic area (e.g., a pico cell) and may allow unrestricted access by terminals with service subscription. A femto or home TRP may cover a relatively small geographic area (e.g., a femto cell) and may allow restricted access by terminals having association with the femto cell (e.g., terminals for users in a home).

As noted, whileFIG.1depicts nodes configured to communicate according to 5G communication protocols, nodes configured to communicate according to other communication protocols, such as, for example, an LTE protocol or IEEE 802.11x protocol, may be used. For example, in an Evolved Packet System (EPS) providing LTE wireless access to the UE105, a RAN may comprise an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) which may comprise base stations comprising evolved Node Bs (eNBs). A core network for EPS may comprise an Evolved Packet Core (EPC). An EPS may comprise an E-UTRAN plus EPC, where the E-UTRAN corresponds to the NG-RAN135and the EPC corresponds to the 5GC140inFIG.1.

The gNBs110a,110band the ng-eNB114may communicate with the AMF115, which, for positioning functionality, communicates with the LMF120. The AMF115may support mobility of the UE105, including cell change and handover and may participate in supporting a signaling connection to the UE105and possibly data and voice bearers for the UE105. The LMF120may communicate directly with the UE105, e.g., through wireless communications. The LMF120may support positioning of the UE105when the UE105accesses the NG-RAN135and may support position procedures/methods such as Assisted GNSS (A-GNSS), Observed Time Difference of Arrival (OTDOA), Real Time Kinematics (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), Enhanced Cell ID (E-CID), angle of arrival (AOA), angle of departure (AOD), and/or other position methods. The LMF120may process location services requests for the UE105, e.g., received from the AMF115or from the GMLC125. The LMF120may be connected to the AMF115and/or to the GMLC125. The LMF120may be referred to by other names such as a Location Manager (LM), Location Function (LF), commercial LMF (CLMF), or value added LMF (VLMF). A node/system that implements the LMF120may additionally or alternatively implement other types of location-support modules, such as an Enhanced Serving Mobile Location Center (E-SMLC) or a Secure User Plane Location (SUPL) Location Platform (SLP). At least part of the positioning functionality (including derivation of the location of the UE105) may be performed at the UE105(e.g., using signal measurements obtained by the UE105for signals transmitted by wireless nodes such as the gNBs110a,110band/or the ng-eNB114, and/or assistance data provided to the UE105, e.g. by the LMF120).

The GMLC125may support a location request for the UE105received from the external client130and may forward such a location request to the AMF115for forwarding by the AMF115to the LMF120or may forward the location request directly to the LMF120. A location response from the LMF120(e.g., containing a location estimate for the UE105) may be returned to the GMLC125either directly or via the AMF115and the GMLC125may then return the location response (e.g., containing the location estimate) to the external client130. The GMLC125is shown connected to both the AMF115and LMF120, though one of these connections may be supported by the 5GC140in some implementations.

As further illustrated inFIG.1, the LMF120may communicate with the gNBs110a,110band/or the ng-eNB114using a New Radio Position Protocol A (which may be referred to as NPPa or NRPPa), which may be defined in 3GPP Technical Specification (TS) 38.455. NRPPa may be the same as, similar to, or an extension of the LTE Positioning Protocol A (LPPa) defined in 3GPP TS 36.455, with NRPPa messages being transferred between the gNB110a(or the gNB110b) and the LMF120, and/or between the ng-eNB114and the LMF120, via the AMF115. As further illustrated inFIG.1, the LMF120and the UE105may communicate using an LTE Positioning Protocol (LPP), which may be defined in 3GPP TS 36.355. The LMF120and the UE105may also or instead communicate using a New Radio Positioning Protocol (which may be referred to as NPP or NRPP), which may be the same as, similar to, or an extension of LPP. Here, LPP and/or NPP messages may be transferred between the UE105and the LMF120via the AMF115and the serving gNB110a,110bor the serving ng-eNB114for the UE105. For example, LPP and/or NPP messages may be transferred between the LMF120and the AMF115using a 5G Location Services Application Protocol (LCS AP) and may be transferred between the AMF115and the UE105using a 5G Non-Access Stratum (NAS) protocol. The LPP and/or NPP protocol may be used to support positioning of the UE105using UE-assisted and/or UE-based position methods such as A-GNSS, RTK, OTDOA and/or E-CID. The NRPPa protocol may be used to support positioning of the UE105using network-based position methods such as E-CID (e.g., when used with measurements obtained by the gNB110a,110bor the ng-eNB114) and/or may be used by the LMF120to obtain location related information from the gNBs110a,110band/or the ng-eNB114, such as parameters defining directional SS transmissions from the gNBs110a,110b, and/or the ng-eNB114.

With a UE-assisted position method, the UE105may obtain location measurements and send the measurements to a location server (e.g., the LMF120) for computation of a location estimate for the UE105. For example, the location measurements may include one or more of a Received Signal Strength Indication (RSSI), Round Trip signal propagation Time (RTT), Reference Signal Time Difference (RSTD), Reference Signal Received Power (RSRP) and/or Reference Signal Received Quality (RSRQ) for the gNBs110a,110b, the ng-eNB114, and/or a WLAN AP. The location measurements may also or instead include measurements of GNSS pseudorange, code phase, and/or carrier phase for the SVs190-193.

With a UE-based position method, the UE105may obtain location measurements (e.g., which may be the same as or similar to location measurements for a UE-assisted position method) and may compute a location of the UE105(e.g., with the help of assistance data received from a location server such as the LMF120or broadcast by the gNBs110a,110b, the ng-eNB114, or other base stations or APs).

With a network-based position method, one or more base stations (e.g., the gNBs110a,110b, and/or the ng-eNB114) or APs may obtain location measurements (e.g., measurements of RSSI, RTT, RSRP, RSRQ or Time Of Arrival (TOA) for signals transmitted by the UE105) and/or may receive measurements obtained by the UE105. The one or more base stations or APs may send the measurements to a location server (e.g., the LMF120) for computation of a location estimate for the UE105.

Information provided by the gNBs110a,110b, and/or the ng-eNB114to the LMF120using NRPPa may include timing and configuration information for directional SS transmissions and location coordinates. The LMF120may provide some or all of this information to the UE105as assistance data in an LPP and/or NPP message via the NG-RAN135and the 5GC140.

An LPP or NPP message sent from the LMF120to the UE105may instruct the UE105to do any of a variety of things depending on desired functionality. For example, the LPP or NPP message could contain an instruction for the UE105to obtain measurements for GNSS (or A-GNSS), WLAN, E-CID, and/or OTDOA (or some other position method). In the case of E-CID, the LPP or NPP message may instruct the UE105to obtain one or more measurement quantities (e.g., beam ID, beam width, mean angle, RSRP, RSRQ measurements) of directional signals transmitted within particular cells supported by one or more of the gNBs110a,110b, and/or the ng-eNB114(or supported by some other type of base station such as an eNB or WiFi AP). The UE105may send the measurement quantities back to the LMF120in an LPP or NPP message (e.g., inside a 5G NAS message) via the serving gNB110a(or the serving ng-eNB114) and the AMF115.

As noted, while the communication system100is described in relation to 5G technology, the communication system100may be implemented to support other communication technologies, such as GSM, WCDMA, LTE, etc., that are used for supporting and interacting with mobile devices such as the UE105(e.g., to implement voice, data, positioning, and other functionalities). In some such embodiments, the 5GC140may be configured to control different air interfaces. For example, the 5GC140may be connected to a WLAN using a Non-3GPP InterWorking Function (N3IWF, not shownFIG.1) in the 5GC150. For example, the WLAN may support IEEE 802.11 WiFi access for the UE105and may comprise one or more WiFi APs. Here, the N3IWF may connect to the WLAN and to other elements in the 5GC140such as the AMF115. In some embodiments, both the NG-RAN135and the 5GC140may be replaced by one or more other RANs and one or more other core networks. For example, in an EPS, the NG-RAN135may be replaced by an E-UTRAN containing eNBs and the 5GC140may be replaced by an EPC containing a Mobility Management Entity (MME) in place of the AMF115, an E-SMLC in place of the LMF120, and a GMLC that may be similar to the GMLC125. In such an EPS, the E-SMLC may use LPPa in place of NRPPa to send and receive location information to and from the eNBs in the E-UTRAN and may use LPP to support positioning of the UE105. In these other embodiments, positioning of the UE105using directional PRSs may be supported in an analogous manner to that described herein for a 5G network with the difference that functions and procedures described herein for the gNBs110a,110b, the ng-eNB114, the AMF115, and the LMF120may, in some cases, apply instead to other network elements such eNBs, WiFi APs, an MME, and an E-SMLC.

As noted, in some embodiments, positioning functionality may be implemented, at least in part, using the directional SS beams, sent by base stations (such as the gNBs110a,110b, and/or the ng-eNB114) that are within range of the UE whose position is to be determined (e.g., the UE105ofFIG.1). The UE may, in some instances, use the directional SS beams from a plurality of base stations (such as the gNBs110a,110b, the ng-eNB114, etc.) to compute the UE's position.

Referring also toFIG.2, a UE200is an example of the UE105and comprises a computing platform including a processor210, memory211including software (SW)212, one or more sensors213, a transceiver interface214for a transceiver215, a user interface216, a Satellite Positioning System (SPS) receiver217, a camera218, and a position (motion) device219. The processor210, the memory211, the sensor(s)213, the transceiver interface214, the user interface216, the SPS receiver217, the camera218, and the position (motion) device219may be communicatively coupled to each other by a bus220(which may be configured, e.g., for optical and/or electrical communication). One or more of the shown apparatus (e.g., the camera218, the position (motion) device219, and/or one or more of the sensor(s)213, etc.) may be omitted from the UE200. The processor210may include one or more intelligent hardware devices, e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc. The processor210may comprise multiple processors including a general-purpose/application processor230, a Digital Signal Processor (DSP)231, a modem processor232, a video processor233, and/or a sensor processor234. One or more of the processors230-234may comprise multiple devices (e.g., multiple processors). For example, the sensor processor234may comprise, e.g., processors for radio frequency (RF) sending (with one or more wireless signals transmitted and reflections used to identify, map and/or track an object), and/or ultrasound, etc. The modem processor232may support dual SIM/dual connectivity (or even more SIMs). For example, a SIM (Subscriber Identity Module or Subscriber Identification Module) may be used by an Original Equipment Manufacturer (OEM), and another SIM may be used by an end user of the UE200for connectivity. The memory211is a non-transitory storage medium that may include random access memory (RAM), flash memory, disc memory, and/or read-only memory (ROM), etc. The memory211stores the software212which may be processor-readable, processor-executable software code containing instructions that are configured to, when executed, cause the processor210to perform various functions described herein. Alternatively, the software212may not be directly executable by the processor210but may be configured to cause the processor210, e.g., when compiled and executed, to perform the functions. The description may refer to the processor210performing a function, but this includes other implementations such as where the processor210executes software and/or firmware. The description may refer to the processor210performing a function as shorthand for one or more of the processors230-234performing the function. The description may refer to the UE200performing a function as shorthand for one or more appropriate components of the UE200performing the function. The processor210may include a memory with stored instructions in addition to and/or instead of the memory211. Functionality of the processor210is discussed more fully below.

The configuration of the UE200shown inFIG.2is an example and not limiting of the disclosure, including the claims, and other configurations may be used. For example, an example configuration of the UE includes one or more of the processors230-234of the processor210, the memory211, and the wireless transceiver240. Other example configurations include one or more of the processors230-234of the processor210, the memory211, the wireless transceiver240, and one or more of the sensor(s)213, the user interface216, the SPS receiver217, the camera218, the PMD219, and/or the wired transceiver250.

The UE200may comprise the modem processor232that may be capable of performing baseband processing of signals received and down-converted by the transceiver215and/or the SPS receiver217. The modem processor232may perform baseband processing of signals to be upconverted for transmission by the transceiver215. Also or alternatively, baseband processing may be performed by the processor230and/or the DSP231. Other configurations, however, may be used to perform baseband processing.

The UE200may include the sensor(s)213that may include, for example, an Inertial Measurement Unit (IMU)270, one or more magnetometers271, and/or one or more environment sensors272. The IMU270may comprise one or more inertial sensors, for example, one or more accelerometers273(e.g., collectively responding to acceleration of the UE200in three dimensions) and/or one or more gyroscopes274. The magnetometer(s) may provide measurements to determine orientation (e.g., relative to magnetic north and/or true north) that may be used for any of a variety of purposes, e.g., to support one or more compass applications. The environment sensor(s)272may comprise, for example, one or more temperature sensors, one or more barometric pressure sensors, one or more ambient light sensors, one or more camera imagers, and/or one or more microphones, etc. The sensor(s)213may generate analog and/or digital signals indications of which may be stored in the memory211and processed by the DSP231and/or the processor230in support of one or more applications such as, for example, applications directed to positioning and/or navigation operations. The sensors processing subsystem may be embedded in a low power core that facilitates continuous logging and derivation of sensor parameters required for high level functions such as temperature sensing, location assist or dead reckoning.

The sensor(s)213may be used in relative location measurements, relative location determination, motion determination, etc. Information detected by the sensor(s)213may be used for motion detection, relative displacement, dead reckoning, sensor-based location determination, and/or sensor-assisted location determination. The sensor(s)213may be useful to determine whether the UE200is fixed (stationary) or mobile and/or whether to report certain useful information to the LMF120regarding the mobility of the UE200. For example, based on the information obtained/measured by the sensor(s)213, the UE200may notify/report to the LMF120that the UE200has detected movements or that the UE200has moved, and report the relative displacement/distance (e.g., via dead reckoning, or sensor-based location determination, or sensor-assisted location determination enabled by the sensor(s)213). In another example, for relative positioning information, the sensors/IMU can be used to determine the angle and/or orientation of the other device with respect to the UE200, etc.

The IMU270may be configured to provide measurements about a direction of motion and/or a speed of motion of the UE200, which may be used in relative location determination. For example, the one or more accelerometers273and/or the one or more gyroscopes274of the IMU270may detect, respectively, a linear acceleration and a speed of rotation of the UE200. The linear acceleration and speed of rotation measurements of the UE200may be integrated over time to determine an instantaneous direction of motion as well as a displacement of the UE200. The instantaneous direction of motion and the displacement may be integrated to determine a location of the UE200. For example, a reference location of the UE200may be determined, e.g., using the SPS receiver217(and/or by some other means) for a moment in time and measurements from the accelerometer(s)273and gyroscope(s)274taken after this moment in time may be used in dead reckoning to determine present location of the UE200based on movement (direction and distance) of the UE200relative to the reference location.

The magnetometer(s)271may determine magnetic field strengths in different directions which may be used to determine orientation of the UE200. For example, the orientation may be used to provide a digital compass for the UE200. The magnetometer(s)271may include a two-dimensional magnetometer configured to detect and provide indications of magnetic field strength in two orthogonal dimensions. Also or alternatively, the magnetometer(s)271may include a three-dimensional magnetometer configured to detect and provide indications of magnetic field strength in three orthogonal dimensions. The magnetometer(s)271may provide means for sensing a magnetic field and providing indications of the magnetic field, e.g., to the processor210.

The transceiver215may include a wireless transceiver240and a wired transceiver250configured to communicate with other devices through wireless connections and wired connections, respectively. For example, the wireless transceiver240may include a transmitter242and receiver244coupled to one or more antennas246for transmitting (e.g., on one or more uplink channels and/or one or more sidelink channels) and/or receiving (e.g., on one or more downlink channels and/or one or more sidelink channels) wireless signals248and transducing signals from the wireless signals248to wired (e.g., electrical and/or optical) signals and from wired (e.g., electrical and/or optical) signals to the wireless signals248. Thus, the transmitter242may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver244may include multiple receivers that may be discrete components or combined/integrated components. The wireless transceiver240may be configured to communicate signals (e.g., with TRPs and/or one or more other devices) according to a variety of radio access technologies (RATs) such as 5G New Radio (NR), GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Phone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long-Term Evolution), LTE Direct (LTE-D), 3GPP LTE-V2X (Vehicle-to-Everything) (PC5), V2C (Uu), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth®, Zigbee, 5G CV2X (Sidelink), 5G ProSe, etc. New Radio may use mm-wave frequencies and/or sub-6 GHz frequencies. The wired transceiver250may include a transmitter252and a receiver254configured for wired communication, e.g., with the NG-RAN135to send communications to, and receive communications from, the gNB110a, for example. The transmitter252may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver254may include multiple receivers that may be discrete components or combined/integrated components. The wired transceiver250may be configured, e.g., for optical communication and/or electrical communication. The transceiver215may be communicatively coupled to the transceiver interface214, e.g., by optical and/or electrical connection. The transceiver interface214may be at least partially integrated with the transceiver215.

The user interface216may comprise one or more of several devices such as, for example, a speaker, microphone, display device, vibration device, keyboard, touch screen, etc. The user interface216may include more than one of any of these devices. The user interface216may be configured to enable a user to interact with one or more applications hosted by the UE200. For example, the user interface216may store indications of analog and/or digital signals in the memory211to be processed by DSP231and/or the general-purpose processor230in response to action from a user. Similarly, applications hosted on the UE200may store indications of analog and/or digital signals in the memory211to present an output signal to a user. The user interface216may include an audio input/output (I/O) device comprising, for example, a speaker, a microphone, digital-to-analog circuitry, analog-to-digital circuitry, an amplifier and/or gain control circuitry (including more than one of any of these devices). Other configurations of an audio I/O device may be used. Also or alternatively, the user interface216may comprise one or more touch sensors responsive to touching and/or pressure, e.g., on a keyboard and/or touch screen of the user interface216.

The SPS receiver217(e.g., a Global Positioning System (GPS) receiver) may be capable of receiving and acquiring SPS signals260via an SPS antenna262. The antenna262is configured to transduce the wireless signals260to wired signals, e.g., electrical or optical signals, and may be integrated with the antenna246. The SPS receiver217may be configured to process, in whole or in part, the acquired SPS signals260for estimating a location of the UE200. For example, the SPS receiver217may be configured to determine location of the UE200by trilateration using the SPS signals260. The general-purpose processor230, the memory211, the DSP231and/or one or more specialized processors (not shown) may be utilized to process acquired SPS signals, in whole or in part, and/or to calculate an estimated location of the UE200, in conjunction with the SPS receiver217. The memory211may store indications (e.g., measurements) of the SPS signals260and/or other signals (e.g., signals acquired from the wireless transceiver240) for use in performing positioning operations. The general-purpose processor230, the DSP231, and/or one or more specialized processors, and/or the memory211may provide or support a location engine for use in processing measurements to estimate a location of the UE200.

The UE200may include the camera218for capturing still or moving imagery. The camera218may comprise, for example, an imaging sensor (e.g., a charge coupled device or a CMOS imager), a lens, analog-to-digital circuitry, frame buffers, etc. Additional processing, conditioning, encoding, and/or compression of signals representing captured images may be performed by the general-purpose processor230and/or the DSP231. Also or alternatively, the video processor233may perform conditioning, encoding, compression, and/or manipulation of signals representing captured images. The video processor233may decode/decompress stored image data for presentation on a display device (not shown), e.g., of the user interface216.

The position (motion) device (PMD)219may be configured to determine a position and possibly motion of the UE200. For example, the PMD219may communicate with, and/or include some or all of, the SPS receiver217. The PMD219may also or alternatively be configured to determine location of the UE200using terrestrial-based signals (e.g., at least some of the signals248) for trilateration, for assistance with obtaining and using the SPS signals260, or both. The PMD219may be configured to use one or more other techniques (e.g., relying on the UE's self-reported location (e.g., part of the UE's position beacon)) for determining the location of the UE200, and may use a combination of techniques (e.g., SPS and terrestrial positioning signals) to determine the location of the UE200. The PMD219may include one or more of the sensors213(e.g., gyroscope(s), accelerometer(s), magnetometer(s), etc.) that may sense orientation and/or motion of the UE200and provide indications thereof that the processor210(e.g., the processor230and/or the DSP231) may be configured to use to determine motion (e.g., a velocity vector and/or an acceleration vector) of the UE200. The PMD219may be configured to provide indications of uncertainty and/or error in the determined position and/or motion.

Referring also toFIG.3, an example of a TRP300of the gNB110a, gNB110b, ng-eNB114comprises a computing platform including a processor310, memory311including software (SW)312, a transceiver315, and (optionally) an SPS receiver317. The processor310, the memory311, the transceiver315, and the SPS receiver317may be communicatively coupled to each other by a bus320(which may be configured, e.g., for optical and/or electrical communication). One or more of the shown apparatus (e.g., a wireless interface and/or the SPS receiver317) may be omitted from the TRP300. The SPS receiver317may be configured similarly to the SPS receiver217to be capable of receiving and acquiring SPS signals360via an SPS antenna362. The processor310may include one or more intelligent hardware devices, e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc. The processor310may comprise multiple processors (e.g., including a general-purpose/application processor, a DSP, a modem processor, a video processor, and/or a sensor processor as shown inFIG.2). The memory311is a non-transitory storage medium that may include random access memory (RAM)), flash memory, disc memory, and/or read-only memory (ROM), etc. The memory311stores the software312which may be processor-readable, processor-executable software code containing instructions that are configured to, when executed, cause the processor310to perform various functions described herein. Alternatively, the software312may not be directly executable by the processor310but may be configured to cause the processor310, e.g., when compiled and executed, to perform the functions. The description may refer to the processor310performing a function, but this includes other implementations such as where the processor310executes software and/or firmware. The description may refer to the processor310performing a function as shorthand for one or more of the processors contained in the processor310performing the function. The description may refer to the TRP300performing a function as shorthand for one or more appropriate components of the TRP300(and thus of one of the gNB110a, gNB110b, ng-eNB114) performing the function. The processor310may include a memory with stored instructions in addition to and/or instead of the memory311. Functionality of the processor310is discussed more fully below.

The transceiver315may include a wireless transceiver340and a wired transceiver350configured to communicate with other devices through wireless connections and wired connections, respectively. For example, the wireless transceiver340may include a transmitter342and receiver344coupled to one or more antennas346for transmitting (e.g., on one or more uplink channels) and/or receiving (e.g., on one or more downlink channels) wireless signals348and transducing signals from the wireless signals348to wired (e.g., electrical and/or optical) signals and from wired (e.g., electrical and/or optical) signals to the wireless signals348. Thus, the transmitter342may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver344may include multiple receivers that may be discrete components or combined/integrated components. The wireless transceiver340may be configured to communicate signals (e.g., with the UE200, one or more other UEs, and/or one or more other devices) according to a variety of radio access technologies (RATs) such as 5G New Radio (NR), GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Phone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long-Term Evolution), LTE Direct (LTE-D), 3GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), 802.15, Bluetooth®, Zigbee, UWB, mmWave, etc. The wired transceiver350may include a transmitter352and a receiver354configured for wired communication, e.g., with the network140to send communications to, and receive communications from, the LMF120or other network server, for example. The transmitter352may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver354may include multiple receivers that may be discrete components or combined/integrated components. The wired transceiver350may be configured, e.g., for optical communication and/or electrical communication.

The configuration of the TRP300shown inFIG.3is an example and not limiting of the disclosure, including the claims, and other configurations may be used. For example, the description herein discusses that the TRP300is configured to perform or performs several functions, but one or more of these functions may be performed by the LMF120and/or the UE200(i.e., the LMF120and/or the UE200may be configured to perform one or more of these functions).

Referring also toFIG.4, an example server, such as the LMF120, comprises a computing platform including a processor410, memory411including software (SW)412, and a transceiver415. The processor410, the memory411, and the transceiver415may be communicatively coupled to each other by a bus420(which may be configured, e.g., for optical and/or electrical communication). One or more of the shown apparatus (e.g., a wireless interface) may be omitted from the server400. The processor410may include one or more intelligent hardware devices, e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc. The processor410may comprise multiple processors (e.g., including a general-purpose/application processor, a DSP, a modem processor, a video processor, and/or a sensor processor as shown inFIG.2). The memory411is a non-transitory storage medium that may include random access memory (RAM)), flash memory, disc memory, and/or read-only memory (ROM), etc. The memory411stores the software412which may be processor-readable, processor-executable software code containing instructions that are configured to, when executed, cause the processor410to perform various functions described herein. Alternatively, the software412may not be directly executable by the processor410but may be configured to cause the processor410, e.g., when compiled and executed, to perform the functions. The description may refer to the processor410performing a function, but this includes other implementations such as where the processor410executes software and/or firmware. The description may refer to the processor410performing a function as shorthand for one or more of the processors contained in the processor410performing the function. The description may refer to the server400(or the LMF120) performing a function as shorthand for one or more appropriate components of the server400performing the function. The processor410may include a memory with stored instructions in addition to and/or instead of the memory411. Functionality of the processor410is discussed more fully below.

The transceiver415may include a wireless transceiver440and a wired transceiver450configured to communicate with other devices through wireless connections and wired connections, respectively. For example, the wireless transceiver440may include a transmitter442and receiver444coupled to one or more antennas446for transmitting (e.g., on one or more downlink channels) and/or receiving (e.g., on one or more uplink channels) wireless signals448and transducing signals from the wireless signals448to wired (e.g., electrical and/or optical) signals and from wired (e.g., electrical and/or optical) signals to the wireless signals448. Thus, the transmitter442may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver444may include multiple receivers that may be discrete components or combined/integrated components. The wireless transceiver440may be configured to communicate signals (e.g., with the UE200, one or more other UEs, and/or one or more other devices) according to a variety of radio access technologies (RATs) such as 5G New Radio (NR), GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Phone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long-Term Evolution), LTE Direct (LTE-D), 3GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth®, BLE, Zigbee etc. The wired transceiver450may include a transmitter452and a receiver454configured for wired communication, e.g., with the NG-RAN135to send communications to, and receive communications from, the TRP300, for example. The transmitter452may include multiple transmitters that may be discrete components or combined/integrated components, and/or the receiver454may include multiple receivers that may be discrete components or combined/integrated components. The wired transceiver450may be configured, e.g., for optical communication and/or electrical communication.

The configuration of the server400shown inFIG.4is an example and not limiting of the disclosure, including the claims, and other configurations may be used. For example, the wireless transceiver440may be omitted. Also or alternatively, the description herein discusses that the server400is configured to perform or performs several functions, but one or more of these functions may be performed by the TRP300and/or the UE200(i.e., the TRP300and/or the UE200may be configured to perform one or more of these functions).

Referring toFIG.5A, an example of a diagram of a round trip time measurement session500is shown. The general approach includes a Responding station502and an Initiating station504. The responding station502and the initiating station504may be a UE such as the UE200, or other wireless mobile device configured to participate in time-of-flight based positioning. In an example, and not a limitation, the RTT measurement session500may be based on Fine Timing Measurement messages exchanged between the responding and initiating stations502,504. Other messages and signals such as positioning reference signals (PRS), sounding reference signals (SRS), Infra-Red camera signals, or other reference signals may be used to determine time-of-flight information between two UEs. The RTT session500may utilize a FTM Protocol (e.g., 802.11mc D4.3 section 10.24.6) to enable two stations to exchange round trip measurement frames (e.g., FTM frames). The initiating station504may compute the round trip time by recording the TOA (i.e., t2) of the FTM frame from the responding station502and recording the TOD of an acknowledgement frame (ACK) of the FTM frame (i.e., t3). The responding station502may record the TOD of the FTM frame (i.e., t1) and the TOA of the ACK received from initiating station504(i.e., t4). Variations of message formats may enable the timing values to be transferred between the responding and initiating stations502,504. The RTT is thus computed as:
RTT=[(t4−t1)−(t3−t2)]  (1)

The RTT session500may allow the initiating station504to obtain its range with the responding station502. An FTM session is an example of a ranging technique between the responding station502and the initiating station504. Other ranging techniques such as TDOA, TOA/TOF may also be used to determine the relative positions of the two stations. Other signaling may also be used to enable a negotiation process, the measurement exchange(s), and a termination process. For example, Wi-Fi 802.11az Ranging Null Data Packet (NDP) and Trigger-Based (TB) Ranging NDP sessions may also be used.

Referring toFIG.5B, an example Wi-Fi wireless communications network550according to aspects of the disclosure is shown. In the example ofFIG.5B, a location server552(which may correspond to any of the servers described herein) is configured to calculate a position estimate for a UE554, or assist another entity (e.g., an AP, the UE554, another UE, a location server, a third party application, etc.) to calculate a position estimate of the UE554. The UE554may communicate wirelessly with a plurality of Wi-Fi access points556-1,556-2, and556-3(which may correspond to any of the TRPs300described herein) using RF signals and standardized protocols for the modulation of the RF signals and the exchange of information packets. By extracting different types of information from the exchanged RF signals, and utilizing the layout of the Wi-Fi wireless network550(i.e., the AP's locations, geometry, etc.), the location server552may determine a position of the UE554, or assist in the determination of the position, in a predefined reference coordinate system. In an aspect, the location server552may specify the position using a two-dimensional coordinate system; however, the aspects disclosed herein are not so limited, and may also be applicable to determining positions using a three-dimensional coordinate system, if the extra dimension is desired. Additionally, whileFIG.5Billustrates one UE554and three AP556-1,556-2,556-3, as will be appreciated, there may be more UEs554and more base stations.

To support position estimates, the APs556-1,556-2,556-3may be configured to broadcast reference RF signals to UEs in their coverage area to enable a UE554to measure characteristics of such reference RF signals. For example, the UE554may measure the ToA and/or RSSI of specific reference RF signals transmitted by at least three different APs and may use the RTT positioning method to report these ToAs (and additional information) back to the location server552(e.g., via a serving AP). In order to determine the position (x, y) of the UE554, the entity determining the position of the UE554needs to know the locations of the APs556-1,556-2,556-3, which may be represented in a reference coordinate system as (xk, yk), where k=1, 2, 3 in the example ofFIG.5B. Where one of the APs556-2(e.g., the serving AP) or the UE554determines the position of the UE554, the locations of the involved APs556-1,556-3may be provided to the serving AP556-2or the UE554by the location server552(which has information of the network geometry). Alternatively, the location server552may determine the position of the UE554using the known network geometry.

Either the UE554or the respective APs556-1,556-2,556-3may determine the distance (dk, where k=1, 2, 3) between the UE554and the respective APs556-1,556-2,556-3. In an aspect, determining the RTT558-1,558-2,558-3of signals exchanged between the UE554and any AP556-1,556-2,556-3can be performed and converted to a distance (dk). RTT techniques can measure the time between sending a signaling message (e.g., reference RF signals) and receiving a response. The FTM procedures inFIG.5Aare an example of a RTT technique. These methods may utilize calibration to remove any processing and hardware delays. In some environments, it may be assumed that the processing delays for the UE554and the APs556-1,556-2,556-3are the same.

Once each distance dkis determined, the UE554, a AP556-1,556-2,556-3, or the location server552can solve for the position (x, y) of the UE554by using a variety of known geometric techniques, such as, for example, trilateration. FromFIG.5B, it can be seen that the position of the UE554ideally lies at the common intersection of three semicircles, each semicircle being defined by radius dkand center (xk, yk), where k=1, 2, 3.

In some instances, additional information may be obtained in the form of an angle of arrival (AoA) or angle of departure (AoD) that defines a straight line direction (e.g., which may be in a horizontal plane or in three dimensions) or possibly a range of directions (e.g., for the UE554from the location of a AP556-1,556-2,556-3). The intersection of the two directions at or near the point (x, y) can provide another estimate of the location for the UE554. In an example, a single distance and AoA with one of the APs may be used to determine an estimated position of the UE554.

Referring toFIG.6, with further reference toFIG.5B, an example message flow600for passive positioning with a plurality of APs is shown. The message flow600includes the first AP556-1, the second AP556-2, and the UE554. In the message flow600, the AP network550provides passive positioning service by exchanging NDP sounding packets between the APs, and client UEs listen to the packets. The location of the UEs may be estimated based on the received sounding packets. For example, the AP network550may utilize the passive positioning techniques described in 802.11az. In an example, the AP locations may be broadcast to the UEs. In a digital key application, the UE554may be configured to feedback a measurement information to a controller (not shown inFIG.6). In an example, the message flow600includes transmitting a I2R NDP message602at time T1 with the first AP556-1, which is received by the second AP556-2at time T2. The UE554is in a position to receive the I2R NDP602at time T5. The second AP556-2may send an acknowledgment message such as the NDPA message604. The second AP556-2is configured to transmit an R21 NDP message606at time T3, which is received by the first AP556-1at time T4. The UE554is in a position to receive the R21 NDP606at time T6. The first AP556-1and/or the second AP556-2may be configured to indicate (e.g., via broadcasting or other signaling) the turnaround time (i.e., T3−T2), the time of flight (i.e., T2−T1), and other assistance data (e.g., locations of the APs556-1,556-2). In an example, the first AP556-1may indicate the time of flight, and the second AP556-2may indicate the turnaround time. In an embodiment, the UE554is configured to perform RSTD measurements based on the time of arrivals T5 and T6. In an embodiment, the UE554may be configured to store the respective ToAs (T5, T6) with station ID information (e.g., the MAC IDs of the respective first and second APs556-1,556-2) in a local data structure, and then provide the data to a digital key system controller.

Referring toFIG.7, a block diagram of an example communications module702with multiple transceivers is shown. The communications module702may be used as a transceiver in a mobile device, such as the transceiver215in the UE200, or a transceiver in a base station, such as the transceiver315in the TRP300. For example, in a V2X network, the communication module may be included in a Roadside Unit (RSU). The communications module702may be communicatively coupled to a processor704, such as the general-purpose processor230and/or the modem processor232. One or more RF modules such as a UWB module706, a BLE module708, and a WiFi module710may be communicatively coupled to a plurality of antennas714a-nvia one or more multiplexers712. The multiplexers712may include switches, phase shifters, and tuning circuits configured to enable one or more of the RF modules706,708,710to send and receive signals via one or more of the antennas714a-n. For example, the WiFi module710and the UWB module706may be configured to utilize one or more of the antennas714a-nbased on operational frequencies. The phase shifters, and other components within the multiplexers712, may enable beamforming to increase the transmit or receive gain on different boresight angles from the location of the antennas714a-n.

Referring toFIG.8, a diagram800of an example process for sequential range determination is shown. The diagram includes a first UE802and a second UE804. The UEs802,804may have some or all of the components of the UE200, and the UE200may be an example of the UEs802,804. In an example use case, the first UE802may be a component wireless security system, such as a vehicle anti-theft system, and the second UE804may be a smart phone or a wireless key fob. The first UE802is located at a first position806and the second UE804is located at a second position808, which is a first distance812from the first UE802. In an example, the UEs802,804, may be configured to utilize a first RF technology, such as WiFi and/or BLE, to exchange ranging messages such as described inFIGS.5A and5Bover the first distance812. In an example, the first distance812may be approximately 100 m to 500 m, or greater.

In general, UWB utilizes a wide spectrum (500 MHz to several GHz) and high frequency (e.g., 6.5 GHz and 9 GHz) to enable low-power short range positioning. UWB positioning may be configured to measure distances on the order of 10 centimeters at a range of approximately 200 meters. While UWB provides higher positioning resolution, the effective range of UWB positioning is less than other positioning technologies such as WiFi and BLE. The second UE804may move closer to the first UE802(e.g., a driver with a key fob approaches a parked vehicle, an employee approaches a secure door, etc.) and close to a second distance814at a third position810. The second distance814may be the effective range of UWB positioning (e.g., 200 m or less) and the UEs802,804may be configured to exchange UWB ranging messages based on determining the second distance814with another RF technology (e.g., WiFi, BLE). In an embodiment the UEs802,804may halt or reduce the periodicity of WiFi or BLE ranging when the UEs are within the second distance814of one another. The second distance814may be a previously established threshold distance (e.g., stored in memory211), or may be based on evaluation of the channel state between the UEs802,804. For example, the presence of interference or other obstructions may cause a reduction in the second distance814and thus delay the activation of UWB based positioning until the UEs802,804are closer to one another.

The accuracy of the UWB based positioning may be degraded if there are obstructions between the UEs802,804and the measurements are based on NLOS signals. The obstructions may attenuate and/or reflect the UWB signals exchanged between the UEs. The UEs802,804may be configured to utilize different techniques to detect a NLOS condition between two stations. Referring toFIGS.9A-9C, example techniques for detecting NLOS conditions are shown.FIG.9Adepicts a first NLOS detection technique900including a first UE902and a second UE904exchanging messages through a barrier906. The barrier906may be a structure such as a wall, vehicle, or other object which may attenuate a RF signal. In an example, the barrier906may be a user or other persons located between the UEs.902,904. The UEs902,904may be configured to compute a first range based on RTT signals910, and a second range based on a signal strength (e.g., RSSI)912. Since the signals may be attenuated by the barrier906, the second range912(based on RSSI) may indicate a larger distance than the first range (based on RTT). The difference in the RTT based range and the RSSI based range may be used to detect a NLOS condition. As an example, and not a limitation, a difference range of 1 meter or greater may be used to detect a NLOS condition.

Referring toFIG.9B, a second NLOS detection technique920may be based on determining Channel State Information (CSI), such as the Channel Frequency Response (CFR) and/or the corresponding Channel Impulse Response (CIR). For example, a delayed CIR peak922which is later in time than the initial signal detection is an indication of a NLOS path (e.g., the LOS is the first arrival path). The delayed CIR peak922may indicate that the LOS path is obstructed since the signals associated with a NLOS path (e.g., a later arriving path) are stronger. Other channel state techniques as known in the art may be used to detect a NLOS condition.

Referring toFIG.9C, a third NLOS detection technique940may be based on the variance of the time-of-flight (ToF) packets received by a UE. An example variance curve942may indicate that the packets are received via a LOS or NLOS path. For example, a threshold variance value944may be established to detect a NLOS condition. As an example, and not a limitation, the threshold variance value944may be in the range of 0.5 to 2.0 nanoseconds. Other values may be used based on the positioning application and capabilities of the UEs.

Referring toFIG.9D, with further reference toFIGS.7,8and9A-9C, a method950for detecting a NLOS path includes the stages shown. The method950is, however, an example and not limiting. The method950may be altered, e.g., by having stages added, removed, rearranged, combined, performed concurrently, and/or having single stages split into multiple stages.

At stage952, the method includes receiving radio frequency signals from a station. A UE200, including a communications module702, is a means for receiving the RF signals. In an example, the first UE802may receive UWB positioning signals from the second UE804as part of an RTT exchange when the UEs802,804are within the second distance814of one another. In a vehicle security use case, the first UE802may be a controller within a vehicle and configured to enable access to the vehicle when a user (e.g., the second UE804) is within an allowed range (e.g., within 3 feet of the vehicle). The RF signals may be associated with other positioning use cases.

At stage954, the method includes detecting a non-line of sigh path based at least in part on the radio frequency signals. The UE200, including the communications module702and the processor704, are a means for detecting the NLOS path. Continuing the example from stage952, the first UE802may be configured to utilize one or more of the NLOS techniques900,920,940described inFIGS.9A-9Cto detect the NLOS path. For example, the first UE802may evaluate RTT and RSSI ranges, channel state information, and/or the variance of the ToF of packets transmitted by the second UE804. Other NLOS detection techniques may also be used.

Referring toFIGS.10A and10B, example transmit power profiles for a UWB signal are shown. A first transmit profile1002may represent normal operations including transmitting packets of a first duration1004at a first power value1006. The power transmitted from a UWB system may be regulated by local rules. For example, the Federal Communication Commission (FCC) has established limits for the average transmit power and the peak transmit power for UWB devices (e.g., 47 CFR sec. 15.519). The first transmit profile1002may be configured such that the first power value1006is below the peak transmit power limit, as well as being below the average transmit power limit based on the first duration1004. In operation, a UWB device such as the communications module702, may be configured to modify transmitter parameters to adjust the transmit profile. Referring toFIG.10B, a second transmit profile1012may represent high power operations including transmitting packets of a second duration1014at a second power value1016. The second duration1014is shorter than the first duration1004, and the second power value1016is greater than the first power value1006. The second transmit profile1012may be configured such that the second power value1016is below the peak transmit power limit as well as being below the average transmit power limit based on the second duration1014. That is, during high power operations, the UWB transmitter may be configured to increase output power and transmit for shorter durations to ensure compliance with established peak and average power limits. The high powered operations may be used to improve ranging accuracy in NLOS use cases.

Referring toFIG.11, with further reference toFIGS.1-10B, a method1100for obtaining a distance measurement with a wireless node includes the stages shown. The method1100is, however, an example and not limiting. The method1100may be altered, e.g., by having stages added, removed, rearranged, combined, performed concurrently, and/or having single stages split into multiple stages.

At stage1102, the method includes obtaining a first distance measurement using a first radio link. A UE200, including a communications module702and a processor704, may be a means for obtaining the first distance measurement. A wireless node may be a UE or other wireless controller configured to obtain UWB based range measurements. In vehicle security use cases, the wireless node may be a digital key fob or a controller on board a vehicle configured to detect a range to a user (e.g., the user's key fob or smartphone). In an example, referring toFIG.8, the first UE802and the second UE804may be configured to exchange positioning measurements to determine the first distance measurement. The positioning measurements may be based on the first radio link such as WiFi or BLE. The positioning measurements may be based on RTT procedures such as depicted inFIG.5A, or other positioning procedures such as RSSI (e.g., BLE positioning).

At stage1104, the method includes determining a status of a second radio link in response to the first distance measurement being less than a threshold distance. The UE200, including the communications module702and the processor704, may be a means for determining the status of the second radio link. In an example, the threshold distance may correspond to the effective range of UWB based positioning (e.g., 100-200 m), and determining the status of the second radio link may include attempting to connect to a station with the second radio link. In an embodiment, determining the status of the second radio link may include obtaining one or more range measurements with the second radio link and determining if the resulting range measurements are within an expected accuracy requirement (e.g., 50, 20, 10 cm or less). Referring toFIG.8, the first UE802may be configured to determine that the second UE804is within the second distance814based on WiFi and/or BLE measurements (e.g., the first radio link), and then switch to UWB and determine the status of the UWB connection and/or the accuracy of the UWB based range measurements.

At stage1106, the method includes configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path. The UE200, including the communications module702and the processor704, may be a means for configuring the one or more transceiver parameters. In an example, the processor704may be configured to detect a NLOS path based at least in part on UWB signals received on the second radio link. Referring toFIGS.9A-9D, for example, determining that the second radio link is being received via a NLOS path may be detected based on one or more techniques such as using ToF to measure distance and determine short range and using RSSI to determine LOS/NLOS (e.g.,FIG.9A), or using ToF to determine short range and using CSI to determine LOS/NLOS (e.g.,FIG.9B), or using ToF to determine short range and using ToF variations across packets (standard deviation for example) to determine LOS/NLOS, (e.g.FIG.9C). Other methods may also be used to determine that the second radio link is utilizing a NLOS path.

In response to determining the second radio link is utilizing a NLOS path, the processor704may configure or reconfigure one or more transceiver parameters such as including transmit power, packet length, idle time and a number of receive antennas to improve UWB ranging accuracy while also meeting potential regulatory requirements for UWB transmit power. In an example, the communications module702may have transmit power headroom available and the processor704may be configured to increase the transmit power based on the available headroom. In another example, referring toFIGS.10A and10B, the transmit power may be increased from the first power value1006to the second power value1016and the packet lengths may be reduced from the first duration1004to the second duration1014. In an example, the UWB module706may share one or more antennas714a-nwith the WiFi module710since they may be configured to operate in the same frequency band. In an effort to conserve battery power, UWB ranging operations may be triggered by determining the first distance based on ranging operations with the BLE module708. That is, UWB ranging takes place when BLE indicates a close range.

At stage1108, the method includes obtaining a second distance measurement using the second radio link and the one or more transceiver parameters. The UE200, including the communications module702and the processor704, may be a means for obtaining the second distance measurement. In general, when the UE200detects that it is within a short range (e.g., within the first distance) at stage1102, and determines that the second radio link is utilizing a NLOS path, the UE200is configured to adjust one or more transceiver settings to increase the power of the second radio link to reduce the impact of the NLOS path. In an example, the processor704may be configure to coordinate the UWB module706, the BLE module708, the WiFi module710and the multiplexer712to jointly optimize ranging performance. For example, when BLE ranging indicates a close range (e.g., the first distance measurement at stage1102), but the UWB module706has not established a connection (e.g., due to NLOS path), the processor704may be configured to utilize the WiFi module710to measure a few metrics such as ToF, RSSI and CSI using WiFi protocols since Wi-Fi may utilize higher transmit power and has a larger coverage area (e.g., larger range). The processor704may utilize the WiFi measurements to determine metrics, that the UWB module706is using a NLOS path and then configure the one or more transceiver parameters to improve the UWB ranging accuracy. For example, the second distance measurement is obtained using an increase in transmit power, modifying the transmit power profile, or modifying the receiver antenna configuration. Other techniques may also be used to increase the signal output from the UWB module706.

In an example, the first radio link may be a BLE based technology and/or a WiFi based technology, and the second radio link may be a UWB technology. The threshold distance may be 100 meters or less. In an implementation, the threshold distance may be 20 meters. Determining the second radio link is utilizing the non-line of sight path may include receiving a plurality of radio frequency signals on the first radio link or the second radio link, and detecting the non-line of sight path based on the plurality of radio frequency signals. The method1100may further include determining a first range value based on a round trip time associated with the plurality of radio frequency signals, determining a second range value based on a received signal strength indication associated with the plurality of radio frequency signals, and detecting the non-line of sight path based at least in part on a comparison of the first range value and the second range value. Determining a channel state indication may be based on the plurality of radio frequency signals, and detecting the non-line of sight path may be based at least in part on the channel state indication. A time-of-flight variance value associated with the plurality of radio frequency signals may be determined, and detecting the non-line of sight path may be based at least in part on the time-of-flight variance value. The method1100may further include comparing a plurality of signal measurement values obtained via the second radio link to a key performance indicator value, and configuring the one or more transceiver parameters based at least in part on a difference between the plurality of signal measurement values and the key performance indicator value. The wireless node may be a user equipment, a digital key fob, and/or a controller in a vehicle.

Referring toFIG.12, with further reference toFIGS.1-11, a method1200for obtaining a range estimate with an ultrawideband (UWB) device includes the stages shown. The method1200is, however, an example and not limiting. The method1200may be altered, e.g., by having stages added, removed, rearranged, combined, performed concurrently, and/or having single stages split into multiple stages. A UE200, including a communications module702, is a means for implementing the method1200.

At stage1202, the method includes enabling UWB transmissions based on an indication of a short range from BLE transmissions. The distance of a short range may be based on the expected range of a UWB measurement technique (e.g., 200 m or less). For example, the short range may correspond to the second distance814when the first UE802and the second UE804are within the expected range of the UWB measurement technique. At stage1204, the method includes determining if the devices have established a UWB connection. In an example, two UEs may not establish a UWB connection due to various environmental factors such as local interference and the presence of obstructions such as walls, crowds, vehicles, or other objects which may create a NLOS condition. The relative locations of the UEs may also create a NLOS condition. For example, a key fob located in a user's backpack, pocket, or purse may be disposed such that the user is located between the key fob and the vehicle (i.e., the user's body is causing the NLOS condition). At stage1206, the UE200may utilize another radio link, such as WiFi, if the UEs cannot establish a connection. The UEs may utilize WiFi to establish a connection and determine a range and determine whether the UEs are in a LOS or NLOS condition at stage1208. For example, the UEs may utilize procedures such as the RTT/RSSI technique depicted inFIG.9Ato compute a range and determine whether there is a NLOS condition (e.g., the presence of a barrier906). The CIR and ToF variance techniques may also be used with the WiFi signals. If the range computed based on the WiFi signals is greater than the expected UWB range (e.g., greater than 200 m), the method1200may end. In an example, the method1200may then iterate back to stage1202. At stage1210, a WiFi range based on LOS measurements may be output at stage1232as the range estimate. In this circumstance, since a UWB connection could not be established at stage1204, the WiFi range determined at stage1208is the best range estimate.

Referring back to stage1204, if a UWB connection is established then a UWB based range estimate may be obtained at stage1212. The UWB based range may be based on RSSI, RTT or other ToF based methods. At stage1214, the UE200may be configured to determine whether there is a NLOS condition impacting the UWB signals. For example, the techniques described inFIGS.9A-9Dmay be used with UWB signals to detect a NLOS condition. If the range estimate determined at stage1212is based on LOS measurements (e.g., no NLOS condition is detected), then the range estimate is output at stage1232. If a NLOS condition is determined at stage1214, or at stage1208, the method1200may adjust one or more transceiver parameters to increase the transmit and/or receive capabilities of the UWB module706.

In an example, at stage1216, the processor704may be configured to increase the transmit power of the UWB module706based on the available headroom. For example, the UWB module706may be configured to utilize 80% power in normal operations (e.g., at stages1204,1212) and then increase the power (e.g., to 90% or 100%) at stage1216in an effort to improve the UWB signal strength. The UE200may obtain another range estimate at stage1218based on the increased transmitter power setting and then evaluate the quality of the range estimated at stage1220. The accuracy of a plurality of range measurements computed at stage1218may be compared to one another and evaluated against a key performance indicator (KPI) to determine the quality. For example, the KPI for a digital key use case may be measurement values with a variance of less than 20 cm. Other applications and use cases may have different KPI values. If the KPI value is achieved at stage1220, then the range estimate determined at stage1218is output at stage1232.

In an example, at stage1222, the transmit profile of the UWB signals may be modified if the KPI requirements of stage1220are not met. In an example, referring toFIGS.10A and10B, the packet lengths may be decreased and the power per packet may be increased. For example, the packet length may be decreased to 150 micro seconds with 1-2 milliseconds of idle time. The UE200may obtain another range estimate at stage1224based on the increased transmit power and short packet configured at stage1222, as well as the increased transmitter power setting established at stage1216. The KPI of the UWB based range estimate is then evaluated at stage1226. The range estimate determined at stage1224is output at stage1232if the KPI is satisfied.

In an example, at stage1228, the processor704may be configured to enable more antennas714a-nto increase the gain of the receiver in the UWB module706. For example, adding an additional antenna (e.g., for a total of two antennas) may increase the sensitivity 3 dB, and adding two additional antennas (e.g., for a total of three antennas) may increase the sensitivity 5 dB. Other antenna combinations may further increase the receive sensitivity. In an embodiment, the UWB module706and the WiFi module710may be configured to share antennas and the processor704and the multiplexer712may be configured to adjust the antenna utilization. The UE200may obtain another range estimate at stage1230based on the receive antenna configuration implemented at stage1228, as well as the increased transmit power and short packet configured at stage1222, and the increased transmitter power setting established at stage1216. The range estimate obtained at stage1230may be output at stage1232.

While the method1200implements the transceiver parameters described at stages1216,1222,1228in a serial order, the transceiver parameters may be implemented individually in various other sequences and/or in parallel sequences. For example, the receive antenna parameters at stage1228may be implemented first, followed by the increase in transmit power and the decrease in packet length, followed by the increase in transmit power. Other sequences are also possible. In an example, two or more of the parameters may be modified simultaneously (e.g., increase transmit power based on headroom and shortening the packet length, etc.). Various sequential combinations of such parallel modifications may also be used.

Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software and computers, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or a combination of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. For example, one or more functions, or one or more portions thereof, discussed above as occurring in the location server may be performed outside of the location such as by an AP.

Components, functional or otherwise, shown in the figures and/or discussed herein as being connected or communicating with each other are communicatively coupled unless otherwise noted. That is, they may be directly or indirectly connected to enable communication between them.

As used herein, the singular forms “a,” “an,” and “the” include the plural forms as well, unless the context clearly indicates otherwise. For example, “a processor” may include one processor or multiple processors. The terms “comprises,” “comprising,” “includes,” and/or “including,” as used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

A wireless communication system is one in which communications are conveyed wirelessly, i.e., by electromagnetic and/or acoustic waves propagating through atmospheric space rather than through a wire or other physical connection. A wireless communication network may not have all communications transmitted wirelessly, but is configured to have at least some communications transmitted wirelessly. Further, the term “wireless communication device,” or similar term, does not require that the functionality of the device is exclusively, or evenly primarily, for communication, or that the device be a mobile device, but indicates that the device includes wireless communication capability (one-way or two-way), e.g., includes at least one radio (each radio being part of a transmitter, receiver, or transceiver) for wireless communication.

1. A method for obtaining a distance measurement with a wireless node, comprising:obtaining a first distance measurement using a first radio link;determining a status of a second radio link in response to the first distance measurement being less than a threshold distance;configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path; andobtaining a second distance measurement using the second radio link and the one or more transceiver parameters.

2. The method of clause 1 wherein the first radio link comprises a Bluetooth based technology.

3. The method of clause 1 wherein the first radio link comprises a WiFi based technology.

4. The method of clause 1 wherein the second radio link comprises a ultrawideband technology.

5. The method of clause 1 wherein the threshold distance is 100 meters or less.

6. The method of clause 1 wherein determining the second radio link is utilizing the non-line of sight path comprises:receiving a plurality of radio frequency signals on the first radio link or the second radio link; anddetecting the non-line of sight path based on the plurality of radio frequency signals.

7. The method of clause 6 further comprising:determining a first range value based on a round trip time associated with the plurality of radio frequency signals;determining a second range value based on a received signal strength indication associated with the plurality of radio frequency signals; anddetecting the non-line of sight path based at least in part on a comparison of the first range value and the second range value.

8. The method of clause 6 further comprising:determining a channel state indication based on at least one of the plurality of radio frequency signals; anddetecting the non-line of sight path based at least in part on the channel state indication.

9. The method of clause 6 further comprising:determining a time-of-flight variance value associated with the plurality of radio frequency signals; anddetecting the non-line of sight path based at least in part on the time-of-flight variance value.

10. The method of clause 1 further comprising:comparing one or more signal measurement values obtained via the second radio link to a key performance indicator value; andconfiguring the one or more transceiver parameters based at least in part on a difference between the one or more signal measurement values and the key performance indicator value.

11. The method of clause 1 wherein configuring the one or more transceiver parameters includes increasing a transmit output power.

12. The method of clause 1 wherein configuring the one or more transceiver parameters includes decreasing a transmit packet length.

13. The method of clause 1 wherein configuring the one or more transceiver parameters includes modifying a receiver antenna configuration.

14. The method of clause 1 wherein the wireless node is a user equipment.

15. The method of clause 14 wherein the user equipment is a digital key fob.

16. The method of clause 1 wherein the wireless node is a controller in a vehicle.

17. An apparatus, comprising:a memory;at least one transceiver;at least one processor communicatively coupled to the memory and the at least one transceiver, and configured to:obtain a first distance measurement using a first radio link;determine a status of a second radio link in response to the first distance measurement being less than a threshold distance;configure one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path; andobtain a second distance measurement using the second radio link and the one or more transceiver parameters.

18. The apparatus of clause 17 wherein the at least one transceiver includes a Bluetooth module and the first radio link comprises a Bluetooth based technology.

19. The apparatus of clause 17 wherein the at least one transceiver includes a WiFi module and the first radio link comprises a WiFi based technology.

20. The apparatus of clause 17 wherein the at least one transceiver includes an ultrawideband module and the second radio link comprises a ultrawideband technology.

21. The apparatus of clause 17 wherein the threshold distance is 100 meters or less.

22. The apparatus of clause 17 wherein the at least one processor is further configured to:receive a plurality of radio frequency signals on the first radio link or the second radio link; anddetect the non-line of sight path based on the plurality of radio frequency signals.

23. The apparatus of clause 22 wherein the at least one processor is further configured to:determine a first range value based on a round trip time associated with the plurality of radio frequency signals;determine a second range value based on a received signal strength indication associated with the plurality of radio frequency signals; anddetect the non-line of sight path based at least in part on a comparison of the first range value and the second range value.

24. The apparatus of clause 22 wherein the at least one processor is further configured to:determine a channel state indication based on the plurality of radio frequency signals; anddetect the non-line of sight path based at least in part on the channel state indication.

25. The apparatus of clause 22 where the at least one processor is further configured to:determine a time-of-flight variance value associated with the plurality of radio frequency signals; anddetect the non-line of sight path based at least in part on the time-of-flight variance value.

26. The apparatus of clause 17 wherein the at least one processor is further configured to:compare one or more signal measurement values obtained via the second radio link to a key performance indicator value; andconfigure the one or more transceiver parameters based at least in part on a difference between the one or more signal measurement values and the key performance indicator value.

27. The apparatus of clause 17 wherein the at least one processor is further configured to increase a transmit power to configure the one or more transceiver parameters.

28. The apparatus of clause 17 wherein the at least one processor is further configured to decrease a transmit packet length to configure the one or more transceiver parameters.

29. The apparatus of clause 17 wherein the at least one processor is further configured to modify a receiver antenna configuration to configure the one or more transceiver parameters.

30. An apparatus for obtaining a distance measurement with a wireless node, comprising:means for obtaining a first distance measurement using a first radio link;means for determining a status of a second radio link in response to the first distance measurement being less than a threshold distance;means for configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path; andmeans for obtaining a second distance measurement using the second radio link and the one or more transceiver parameters.

31. A non-transitory processor-readable storage medium comprising processor-readable instructions configured to cause one or more processors to obtain a distance measurement with a wireless node, comprising:code for obtaining a first distance measurement using a first radio link;code for determining a status of a second radio link in response to the first distance measurement being less than a threshold distance;code for configuring one or more transceiver parameters associated with the second radio link in response to determining the second radio link is utilizing a non-line of sight path; andcode for obtaining a second distance measurement using the second radio link and the one or more transceiver parameters.