Patent Description:
In <CIT>, methods, apparatus and systems for monitoring a presence or a motion of an object in a proximity of an apparatus are described. In one example, a described apparatus is in a venue for wireless proximity monitoring. The apparatus comprises: a transmitter, a receiver, and a processor. The transmitter is configured for transmitting a wireless signal through a wireless multipath channel, wherein the wireless multipath channel is impacted by a motion of an object within a proximity of the apparatus. The receiver is configured for: receiving the wireless signal through the wireless multipath channel between the transmitter and the receiver, and obtaining a time series of channel information (TSCI) of the wireless multipath channel based on the wireless signal received by the receiver. The processor is configured for monitoring the motion of the object within the proximity of the apparatus based at least partially on the TSCI.

In <CIT>, motion is detected based on bi-directional channel sounding. In an example, a first set of channel information is obtained from a first device. The first set of channel information is based on a first set of wireless signals transmitted from a second device through a space at a first time in a timeframe. A second set of channel information is obtained from the second device. The second set of channel information is based on a second set of wireless signals transmitted from the first device through the space at a second time in the timeframe. The first and second sets of channel information are analyzed to detect a category of motion or a location of detected motion in the space during the timeframe.

In <CIT>, there is described a radio-based object detection method. According to the method, first location information relating to an object of interest are determined with a first device using radio waves. Based on the first location information, a second device from a plurality of candidate devices is selected. A request for determining second location information relating to the object of interest is transmitted via a telecommunication network to the second device.

In <CIT>, there is described an apparatus and a method to estimate a location by using a bistatic range, capable of mutually associating signals reflected from the same target among signals received in a receiver. The method comprises the following steps of: receiving reflective signals which are a signal source emitted from each transmitter and reflected from a plurality of targets, and using the received reflective signals to measure bistatic ranges for each transmitter; using the measured bistatic ranges of each transmitter, a preset transmitter location, and a preset receiver location to generate lines of position (LOP) by the bistatic range of each transmitter; and confirming a cross position of the generated LOPs of each transmitter to generate a correlation among the signals of each transmitter with respect to the same target, and estimating the location of the same target from the confirmed cross position in accordance with the generated correlation. The measure step measures the bistatic ranges and a bistatic speed from the received reflective signals in every preset time.

Various examples are described for systems and methods for bi-static radio-based object location detection.

Features of some embodiments are recited in dependent claims.

The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more certain examples and, together with the description of the example, serve to explain the principles and implementations of the certain examples.

The following description is directed to certain implementations for the purposes of describing innovative aspects of various embodiments. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The described implementations may be implemented in any device, system, or network that is capable of transmitting and receiving radio frequency (RF) signals according to any communication standard, such as any of the Institute of Electrical and Electronics Engineers (IEEE) IEEE <NUM> standards (including those identified as Wi-Fi® technologies), the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Rate Packet Data (HRPD), High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), Advanced Mobile Phone System (AMPS), or other known signals that are used to communicate within a wireless, cellular or internet of things (IoT) network, such as a system utilizing <NUM>, <NUM>, <NUM>, <NUM>, or further implementations thereof, technology.

Examples are described herein in the context of systems and methods for bi-static radio-based object location detection. Those of ordinary skill in the art will realize that the following description is illustrative only and is not intended to be in any way limiting. Reference will now be made in detail to implementations of examples as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following description to refer to the same or like items.

In the interest of clarity, not all of the routine features of the examples described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another.

As used herein, a "wireless signal" comprises an electromagnetic wave that transports information through the space between a transmitter (or transmitting device) and a receiver (or receiving device). As used herein, a transmitter may transmit a single "wireless signal" or multiple "wireless signals" to a receiver. However, the receiver may receive multiple "wireless signals" corresponding to each transmitted wireless signal due to the propagation characteristics of wireless signals through multipath channels. The same transmitted wireless signal on different paths between the transmitter and receiver may be referred to as a "multipath" wireless signal.

People often use wireless devices to communicate with friends and family, e.g., by video chat, text messaging, etc., and to access information available over the Internet. However, wireless technology employs the use of wireless signals that may be used for functionality other than communicating information between electronic devices. For example, a user may have a mobile wireless device (or user equipment or "UE"), such as a wireless phone or tablet, that communicates with a distant wireless base station to wirelessly send and receive data via the wireless network. However, the user may wish to use the wireless device to provide information about the surrounding environment, such as to determine locations of nearby (or even distant) objects. To do so, the user can activate radar functionality within their wireless device that makes use of existing wireless infrastructure and radio transmissions.

For example, the user accesses object location detection functionality on their wireless device, which notifies the wireless network, via a nearby wireless base station the user's device is communicating with, that object location detection functionality will be used. The user's wireless device and the wireless base station then coordinate to determine the location of one or more objects in the vicinity.

To perform the object location detection functionality, the base station first determines the location of the user's wireless device by requesting its location. The user's wireless device then transmits its location to the base station. The base station then transmits an omnidirectional reference signal to the user's wireless device as well as certain timing information. The user's wireless device then determines the ToF and the AoA of the reference signal, assuming a direct line-of-sight (LOS) between the wireless base station and the user's wireless device. This direct-path signal (or substantially direct-path signal) will be referred to as the direct-path reference signal.

However, because the reference signal is transmitted omnidirectionally over a geographic region, it is reflected by one or more objects, and some of these reflections may then arrive at the user's wireless device. The wireless device receives these reflected versions of the reference signal and determines the corresponding ToF and AoA for one or more of them. The user's wireless device then transmits the ToF and AoA information to the base station.

The base station can then use the ToF information and the corresponding AoA information for the reflected reference signals to determine the locations of various objects in the environment. In particular, the ToF information for a reflected reference signal indicates information about an ellipse, where the base station and the user's wireless device represent focus points for the ellipse. In addition, the corresponding AoA provides additional information to identify a point on the ellipse corresponding to the object that reflected the reference signal. The point on the ellipse can then be translated to a geographical coordinate, e.g., a latitude and longitude, using the location information for either (or both) of the base station or the user device. Alternatively, the location on the ellipse can be used to determine the distance from the user device to the object and the heading to the object, thereby identifying a relative location of the object. By performing this technique for one or more reflected signals, the base station can determine the locations of multiple objects in the environment. And while the base station performed some of the processing in this example, the user's wireless device is also capable of sending a reference signal and performing the functionality discussed above.

Using these techniques, wireless devices may be able to help locate objects in an environment using readily available wireless technology and infrastructure rather than using more complex, specialized equipment. In addition, wireless devices provide information to enable electronic devices to learn about an environment, such as in the case of self-driving cars or other autonomous vehicles, or to enable user functionality such as providing locations of nearby landmarks, e.g., buildings, monuments, etc. Further, these techniques do not require the various objects in the environment to be enabled with any wireless capabilities. Instead, by using wireless transmissions that have been reflected from those objects, the objects themselves need not otherwise participate in the process.

This illustrative example is given to introduce the reader to the general subject matter discussed herein and the disclosure is not limited to this example. The following sections describe various additional non-limiting examples and examples of systems and methods for bi-static radio-based object location detection.

<FIG> is a simplified illustration of a positioning system <NUM> in which a UE <NUM>, location server <NUM>, and/or other components of the positioning system <NUM> can use the techniques provided herein for determining and estimated location of UE <NUM>, according to an example. The techniques described herein may be implemented by one or more components of the positioning system <NUM>. The positioning system <NUM> can include: a UE <NUM>; one or more satellites <NUM> (also referred to as space vehicles (SVs)) for a Global Navigation Satellite System (GNSS) such as the Global Positioning System (GPS), GLONASS, Galileo or Beidou; base stations <NUM>; access points (APs) <NUM>; location server <NUM>; network <NUM>; and external client <NUM>. Generally put, the positioning system <NUM> can estimate a location of the UE <NUM> based on RF signals received by and/or sent from the UE <NUM> and known locations of other components (e.g., GNSS satellites <NUM>, base stations <NUM>, APs <NUM>) transmitting and/or receiving the RF signals. Additional details regarding particular location estimation techniques are discussed in more detail with regard to <FIG>.

It should be noted that <FIG> provides only a generalized illustration of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated as necessary. Specifically, although only one UE <NUM> is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may utilize the positioning system <NUM>. Similarly, the positioning system <NUM> may include a larger or smaller number of base stations <NUM> and/or APs <NUM> than illustrated in <FIG>. The illustrated connections that connect the various components in the positioning system <NUM> comprise 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. In some embodiments, for example, the external client <NUM> may be directly connected to location server <NUM>. A person of ordinary skill in the art will recognize many modifications to the components illustrated.

Depending on desired functionality, the network <NUM> may comprise any of a variety of wireless and/or wireline networks. The network <NUM> can, for example, comprise any combination of public and/or private networks, local and/or wide-area networks, and the like. Furthermore, the network <NUM> may utilize one or more wired and/or wireless communication technologies. In some embodiments, the network <NUM> may comprise a cellular or other mobile network, a wireless local area network (WLAN), a wireless wide-area network (WWAN), and/or the Internet, for example. Examples of network <NUM> include a Long-Term Evolution (LTE) wireless network, a Fifth Generation (<NUM>) wireless network (also referred to as New Radio (NR) wireless network or <NUM> NR wireless network), a Wi-Fi WLAN, and the Internet. LTE, <NUM> and NR are wireless technologies defined, or being defined, by the 3rd Generation Partnership Project (3GPP). Network <NUM> may also include more than one network and/or more than one type of network.

The base stations <NUM> and access points (APs) <NUM> are communicatively coupled to the network <NUM>. In some embodiments, the base station <NUM> may be owned, maintained, and/or operated by a cellular network provider, and may employ any of a variety of wireless technologies, as described herein below. Depending on the technology of the network <NUM>, a base station <NUM> may comprise a node B, an Evolved Node B (eNodeB or eNB), a base transceiver station (BTS), a radio base station (RBS), an NR NodeB (gNB), a Next Generation eNB (ng-eNB), or the like. A base station <NUM> that is a gNB or ng-eNB may be part of a Next Generation Radio Access Network (NG-RAN) which may connect to a <NUM> Core Network (5GC) in the case that Network <NUM> is a <NUM> network. An AP <NUM> may comprise a Wi-Fi AP or a Bluetooth® AP, for example. Thus, UE <NUM> can send and receive information with network-connected devices, such as location server <NUM>, by accessing the network <NUM> via a base station <NUM> using a first communication link <NUM>. Additionally or alternatively, because APs <NUM> also may be communicatively coupled with the network <NUM>, UE <NUM> may communicate with network-connected and Internet-connected devices, including location server <NUM>, using a second communication link <NUM>.

As used herein, the term "base station" may generically refer to a single physical transmission point, or multiple co-located physical transmission points, which may be located at a base station <NUM>. A Transmission Reception Point (TRP) (also known as transmit/receive point) corresponds to this type of transmission point, and the term "TRP" may be used interchangeably herein with the terms "gNB," "ng-eNB," and "base station. " In some cases, a base station <NUM> may comprise multiple TRPs - e.g. with each TRP associated with a different antenna or a different antenna array for the base station <NUM>. Physical transmission points may comprise an array of antennas of a base station <NUM> (e.g., as in a Multiple Input-Multiple Output (MIMO) system and/or where the base station employs beamforming). The term "base station" may additionally refer to multiple non-co-located physical transmission points, the physical transmission points may be a Distributed Antenna System (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a Remote Radio Head (RRH) (a remote base station connected to a serving base station).

As used herein, the term "cell" may generically refer to a logical communication entity used for communication with a base station <NUM>, and may be associated with an identifier for distinguishing neighboring cells (e.g., a Physical Cell Identifier (PCID), a Virtual Cell Identifier (VCID)) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine-Type Communication (MTC), Narrowband Internet-of-Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or others) that may provide access for different types of devices. In some cases, the term "cell" may refer to a portion of a geographic coverage area (e.g., a sector) over which the logical entity operates.

The location server <NUM> may comprise a server and/or other computing device configured to determine an estimated location of UE <NUM> and/or provide data (e.g., "assistance data") to UE <NUM> to facilitate location measurement and/or location determination by UE <NUM>. According to some embodiments, location server <NUM> may comprise a Home Secure User Plane Location (SUPL) Location Platform (H-SLP), which may support the SUPL user plane (UP) location solution defined by the Open Mobile Alliance (OMA) and may support location services for UE <NUM> based on subscription information for UE <NUM> stored in location server <NUM>. In some embodiments, the location server <NUM> may comprise, a Discovered SLP (D-SLP) or an Emergency SLP (E-SLP). The location server <NUM> may also comprise an Enhanced Serving Mobile Location Center (E-SMLC) that supports location of UE <NUM> using a control plane (CP) location solution for LTE radio access by UE <NUM>. The location server <NUM> may further comprise a Location Management Function (LMF) that supports location of UE <NUM> using a control plane (CP) location solution for NR or LTE radio access by UE <NUM>.

In a CP location solution, signaling to control and manage the location of UE <NUM> may be exchanged between elements of network <NUM> and with UE <NUM> using existing network interfaces and protocols and as signaling from the perspective of network <NUM>. In a UP location solution, signaling to control and manage the location of UE <NUM> may be exchanged between location server <NUM> and UE <NUM> as data (e.g. data transported using the Internet Protocol (IP) and/or Transmission Control Protocol (TCP)) from the perspective of network <NUM>.

As previously noted (and discussed in more detail below), the estimated location of UE <NUM> may be based on measurements of RF signals sent from and/or received by the UE <NUM>. In particular, these measurements can provide information regarding the relative distance and/or angle of the UE <NUM> from one or more components in the positioning system <NUM> (e.g., GNSS satellites <NUM>, APs <NUM>, base stations <NUM>). The estimated location of the UE <NUM> can be estimated geometrically (e.g., using multiangulation and/or multilateration), based on the distance and/or angle measurements, along with known position of the one or more components.

Although terrestrial components such as APs <NUM> and base stations <NUM> may be fixed, embodiments are not so limited. Mobile components may be used. For example, in some embodiments, a location of the UE <NUM> may be estimated at least in part based on measurements of RF signals <NUM> communicated between the UE <NUM> and one or more other UEs <NUM>, which may be mobile or fixed. When or more other UEs <NUM> are used in the position determination of a particular UE <NUM>, the UE <NUM> for which the position is to be determined may be referred to as the "target UE," and each of the one or more other UEs <NUM> used may be referred to as an "anchor UE. " For position determination of a target UE, the respective positions of the one or more anchor UEs may be known and/or jointly determined with the target UE. Direct communication between the one or more other UEs <NUM> and UE <NUM> may comprise sidelink and/or similar Device-to-Device (D2D) communication technologies. Sidelink, which is defined by 3GPP, is a form of D2D communication under the cellular-based LTE and NR standards.

An estimated location of UE <NUM> can be used in a variety of applications - e.g. to assist direction finding or navigation for a user of UE <NUM> or to assist another user (e.g. associated with external client <NUM>) to locate UE <NUM>. A "location" is also referred to herein as a "location estimate", "estimated location", "location", "position", "position estimate", "position fix", "estimated position", "location fix" or "fix". The process of determining a location may be referred to as "positioning," "position determination," "location determination," or the like. A location of UE <NUM> may comprise an absolute location of UE <NUM> (e.g. a latitude and longitude and possibly altitude) or a relative location of UE <NUM> (e.g. a location expressed as distances north or south, east or west and possibly above or below some other known fixed location or some other location such as a location for UE <NUM> at some known previous time). A location may be specified as a geodetic location comprising coordinates which may be absolute (e.g. latitude, longitude and optionally altitude), relative (e.g. relative to some known absolute location) or local (e.g. X, Y and optionally Z coordinates according to a coordinate system defined relative to a local area such a factory, warehouse, college campus, shopping mall, sports stadium or convention center). A location may instead be a civic location and may then comprise one or more of a street address (e.g. including names or labels for a country, state, county, city, road and/or street, and/or a road or street number), and/or a label or name for a place, building, portion of a building, floor of a building, and/or room inside a building etc. A location may further include an uncertainty or error indication, such as a horizontal and possibly vertical distance by which the location is expected to be in error or an indication of an area or volume (e.g. a circle or ellipse) within which UE <NUM> is expected to be located with some level of confidence (e.g. <NUM>% confidence).

The external client <NUM> may be a web server or remote application that may have some association with UE <NUM> (e.g. may be accessed by a user of UE <NUM>) or may be a server, application, or computer system providing a location service to some other user or users which may include obtaining and providing the location of UE <NUM> (e.g. to enable a service such as friend or relative finder, asset tracking or child or pet location). Additionally or alternatively, the external client <NUM> may obtain and provide the location of UE <NUM> to an emergency services provider, government agency, etc..

As previously noted, the example positioning system <NUM> can be implemented using a wireless communication network, such as an LTE-based or <NUM> NR-based network. <FIG> shows a diagram of a <NUM> NR positioning system <NUM>, illustrating an example of a positioning system (e.g., positioning system <NUM>) implementing <NUM> NR. The <NUM> NR positioning system <NUM> may be configured to determine the location of a UE <NUM> by using access nodes <NUM>, <NUM>, <NUM> (which may correspond with base stations <NUM> and access points <NUM> of <FIG>) and (optionally) an LMF <NUM> (which may correspond with location server <NUM>) to implement one or more positioning methods. Here, the <NUM> NR positioning system <NUM> comprises a UE <NUM>, and components of a <NUM> NR network comprising a Next Generation (NG) Radio Access Network (RAN) (NG-RAN) <NUM> and a <NUM> Core Network (<NUM> CN) <NUM>. A <NUM> network may also be referred to as an NR network; NG-RAN <NUM> may be referred to as a <NUM> RAN or as an NR RAN; and <NUM> CN <NUM> may be referred to as an NG Core network. The <NUM> NR positioning system <NUM> may further utilize information from GNSS satellites <NUM> from a GNSS system like Global Positioning System (GPS) or similar system (e.g. GLONASS, Galileo, Beidou, Indian Regional Navigational Satellite System (IRNSS)). Additional components of the <NUM> NR positioning system <NUM> are described below. The <NUM> NR positioning system <NUM> may include additional or alternative components.

It should be noted that <FIG> provides only 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 only one UE <NUM> is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may utilize the <NUM> NR positioning system <NUM>. Similarly, the <NUM> NR positioning system <NUM> may include a larger (or smaller) number of GNSS satellites <NUM>, gNBs <NUM>, ng-eNBs <NUM>, Wireless Local Area Networks (WLANs) <NUM>, Access and mobility Management Functions (AMF)s <NUM>, external clients <NUM>, and/or other components. The illustrated connections that connect the various components in the <NUM> NR positioning system <NUM> include 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.

The UE <NUM> may comprise and/or 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, UE <NUM> may correspond to a cellphone, smartphone, laptop, tablet, personal data assistant (PDA), navigation device, Internet of Things (IoT) device, or some other portable or moveable device. Typically, though not necessarily, the UE <NUM> may support wireless communication using one or more Radio Access Technologies (RATs) such as using GSM, CDMA, W-CDMA, LTE, High Rate Packet Data (HRPD), IEEE <NUM> Wi-Fi®, Bluetooth, Worldwide Interoperability for Microwave Access (WiMAX™), <NUM> NR (e.g., using the NG-RAN <NUM> and <NUM> CN <NUM>), etc. The UE <NUM> may also support wireless communication using a WLAN <NUM> which (like the one or more RATs, and as previously noted with respect to <FIG>) may connect to other networks, such as the Internet. The use of one or more of these RATs may allow the UE <NUM> to communicate with an external client <NUM> (e.g., via elements of <NUM> CN <NUM> not shown in <FIG>, or possibly via a Gateway Mobile Location Center (GMLC) <NUM>) and/or allow the external client <NUM> to receive location information regarding the UE <NUM> (e.g., via the GMLC <NUM>). The external client <NUM> of <FIG> may correspond to external client <NUM> of <FIG>, as implemented in or communicatively coupled with a <NUM> NR network.

The UE <NUM> may include a single entity or may include multiple entities, such as in a personal area network where a user may employ audio, video and/or data I/O devices, and/or body sensors and a separate wireline or wireless modem. An estimate of a location of the UE <NUM> may be referred to as a location, location estimate, location fix, fix, position, position estimate, or position fix, and may be geodetic, thus providing location coordinates for the UE <NUM> (e.g., latitude and longitude), which may or may not include an altitude component (e.g., height above sea level, height above or depth below ground level, floor level or basement level). Alternatively, a location of the UE <NUM> may be expressed as a civic location (e.g., as a postal address or the designation of some point or small area in a building such as a particular room or floor). A location of the UE <NUM> may also be expressed as an area or volume (defined either geodetically or in civic form) within which the UE <NUM> is expected to be located with some probability or confidence level (e.g., <NUM>%, <NUM>%, etc.). A location of the UE <NUM> may further be a relative location comprising, for example, a distance and direction or relative X, Y (and Z) coordinates defined relative to some origin at a known location which may be defined geodetically, in civic terms, or by reference to a point, area, or volume indicated on a map, floor plan or building plan. In the description contained herein, the use of the term location may comprise any of these variants unless indicated otherwise. When computing the location of a UE, it is common to solve for local X, Y, and possibly Z coordinates and then, if needed, convert the local coordinates into absolute ones (e.g. for latitude, longitude and altitude above or below mean sea level).

Base stations in the NG-RAN <NUM> shown in <FIG> may correspond to base stations <NUM> in <FIG> and may include NR NodeB (gNB) <NUM>-<NUM> and <NUM>-<NUM> (collectively and generically referred to herein as gNBs <NUM>). Pairs of gNBs <NUM> in NG-RAN <NUM> may be connected to one another (e.g., directly as shown in <FIG> or indirectly via other gNBs <NUM>). The communication interface between base stations (gNBs <NUM> and/or ng-eNB <NUM>) may be referred to as an Xn interface <NUM>. Access to the <NUM> network is provided to UE <NUM> via wireless communication between the UE <NUM> and one or more of the gNBs <NUM>, which may provide wireless communications access to the <NUM> CN <NUM> on behalf of the UE <NUM> using <NUM> NR. The wireless interface between base stations (gNBs <NUM> and/or ng-eNB <NUM>) and the UE <NUM> may be referred to as a Uu interface <NUM>. <NUM> NR radio access may also be referred to as NR radio access or as <NUM> radio access. In <FIG>, the serving gNB for UE <NUM> is assumed to be gNB <NUM>-<NUM>, although other gNBs (e.g. gNB <NUM>-<NUM>) may act as a serving gNB if UE <NUM> moves to another location or may act as a secondary gNB to provide additional throughput and bandwidth to UE <NUM>.

Base stations in the NG-RAN <NUM> shown in <FIG> may also or instead include a next generation evolved Node B, also referred to as an ng-eNB, <NUM>. Ng-eNB <NUM> may be connected to one or more gNBs <NUM> in NG-RAN <NUM>-e.g. directly or indirectly via other gNBs <NUM> and/or other ng-eNBs. An ng-eNB <NUM> may provide LTE wireless access and/or evolved LTE (eLTE) wireless access to UE <NUM>. Some gNBs <NUM> (e.g. gNB <NUM>-<NUM>) and/or ng-eNB <NUM> in <FIG> may be configured to function as positioning-only beacons which may transmit signals (e.g., Positioning Reference Signal (PRS)) and/or may broadcast assistance data to assist positioning of UE <NUM> but may not receive signals from UE <NUM> or from other UEs. It is noted that while only one ng-eNB <NUM> is shown in <FIG>, some embodiments may include multiple ng-eNBs <NUM>. Base stations <NUM>, <NUM> may communicate directly with one another via an Xn communication interface. Additionally or alternatively, base stations <NUM>, <NUM> may communicate directly or indirectly with other components of the <NUM> NR positioning system <NUM>, such as the LMF <NUM> and AMF <NUM>.

<NUM> NR positioning system <NUM> may also include one or more WLANs <NUM> which may connect to a Non-3GPP InterWorking Function (N3IWF) <NUM> in the <NUM> CN <NUM> (e.g., in the case of an untrusted WLAN <NUM>). For example, the WLAN <NUM> may support IEEE <NUM> Wi-Fi access for UE <NUM> and may comprise one or more Wi-Fi APs (e.g., APs <NUM> of <FIG>). Here, the N3IWF <NUM> may connect to other elements in the <NUM> CN <NUM> such as AMF <NUM>. In some embodiments, WLAN <NUM> may support another RAT such as Bluetooth. The N3IWF <NUM> may provide support for secure access by UE <NUM> to other elements in <NUM> CN <NUM> and/or may support interworking of one or more protocols used by WLAN <NUM> and UE <NUM> to one or more protocols used by other elements of <NUM> CN <NUM> such as AMF <NUM>. For example, N3IWF <NUM> may support IPSec tunnel establishment with UE <NUM>, termination of IKEv2/IPSec protocols with UE <NUM>, termination of N2 and N3 interfaces to <NUM> CN <NUM> for control plane and user plane, respectively, relaying of uplink (UL) and downlink (DL) control plane Non-Access Stratum (NAS) signaling between UE <NUM> and AMF <NUM> across an N1 interface. In some other embodiments, WLAN <NUM> may connect directly to elements in <NUM> CN <NUM> (e.g. AMF <NUM> as shown by the dashed line in <FIG>) and not via N3IWF <NUM>. For example, direct connection of WLAN <NUM> to 5GCN <NUM> may occur if WLAN <NUM> is a trusted WLAN for 5GCN <NUM> and may be enabled using a Trusted WLAN Interworking Function (TWIF) (not shown in <FIG>) which may be an element inside WLAN <NUM>. It is noted that while only one WLAN <NUM> is shown in <FIG>, some embodiments may include multiple WLANs <NUM>.

Access nodes may comprise any of a variety of network entities enabling communication between the UE <NUM> and the AMF <NUM>. This can include gNBs <NUM>, ng-eNB <NUM>, WLAN <NUM>, and/or other types of cellular base stations. However, access nodes providing the functionality described herein may additionally or alternatively include entities enabling communications to any of a variety of RATs not illustrated in <FIG>, which may include non-cellular technologies. Thus, the term "access node," as used in the embodiments described herein below, may include but is not necessarily limited to a gNB <NUM>, ng-eNB <NUM> or WLAN <NUM>.

In some embodiments, an access node, such as a gNB <NUM>, ng-eNB <NUM>, or WLAN <NUM> (alone or in combination with other components of the <NUM> NR positioning system <NUM>), may be configured to, in response to receiving a request for location information from the LMF <NUM>, obtain location measurements of uplink (LTL) signals received from the UE <NUM>) and/or obtain downlink (DL) location measurements from the UE <NUM> that were obtained by UE <NUM> for DL signals received by UE <NUM> from one or more access nodes. As noted, while <FIG> depicts access nodes <NUM>, <NUM>, and <NUM> configured to communicate according to <NUM> NR, LTE, and Wi-Fi communication protocols, respectively, access nodes configured to communicate according to other communication protocols may be used, such as, for example, a Node B using a Wideband Code Division Multiple Access (WCDMA) protocol for a Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio Access Network (UTRAN), an eNB using an LTE protocol for an Evolved UTRAN (E-UTRAN), or a Bluetooth® beacon using a Bluetooth protocol for a WLAN. For example, in a <NUM> Evolved Packet System (EPS) providing LTE wireless access to UE <NUM>, a RAN may comprise an E-UTRAN, which may comprise base stations comprising eNBs supporting LTE wireless access. A core network for EPS may comprise an Evolved Packet Core (EPC). An EPS may then comprise an E-UTRAN plus an EPC, where the E-UTRAN corresponds to NG-RAN <NUM> and the EPC corresponds to 5GCN <NUM> in <FIG>. The methods and techniques described herein for obtaining a civic location for UE <NUM> may be applicable to such other networks.

The gNBs <NUM> and ng-eNB <NUM> can communicate with an AMF <NUM>, which, for positioning functionality, communicates with an LMF <NUM>. The AMF <NUM> may support mobility of the UE <NUM>, including cell change and handover of UE <NUM> from an access node <NUM>, <NUM>, or <NUM> of a first RAT to an access node <NUM>, <NUM>, or <NUM> of a second RAT. The AMF <NUM> may also participate in supporting a signaling connection to the UE <NUM> and possibly data and voice bearers for the UE <NUM>. The LMF <NUM> may support positioning of the UE <NUM> using a CP location solution when UE <NUM> accesses the NG-RAN <NUM> or WLAN <NUM> and may support position procedures and methods, including UE assisted/UE based and/or network based procedures/methods, such as Assisted GNSS (A-GNSS), Observed Time Difference Of Arrival (OTDOA) (which may be referred to in NR as Time Difference Of Arrival (TDOA)), Real Time Kinematic (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), Enhance Cell ID (ECID), angle of arrival (AoA), angle of departure (AoD), WLAN positioning, round trip signal propagation delay (RTT), multi-cell RTT, and/or other positioning procedures and methods. The LMF <NUM> may also process location service requests for the UE <NUM>, e.g., received from the AMF <NUM> or from the GMLC <NUM>. The LMF <NUM> may be connected to AMF <NUM> and/or to GMLC <NUM>. In some embodiments, a network such as 5GCN <NUM> may additionally or alternatively implement other types of location-support modules, such as an Evolved Serving Mobile Location Center (E-SMLC) or a SUPL Location Platform (SLP). It is noted that in some embodiments, at least part of the positioning functionality (including determination of a UE <NUM>'s location) may be performed at the UE <NUM> (e.g., by measuring downlink PRS (DL-PRS) signals transmitted by wireless nodes such as gNBs <NUM>, ng-eNB <NUM> and/or WLAN <NUM>, and/or using assistance data provided to the UE <NUM>, e.g., by LMF <NUM>).

The Gateway Mobile Location Center (GMLC) <NUM> may support a location request for the UE <NUM> received from an external client <NUM> and may forward such a location request to the AMF <NUM> for forwarding by the AMF <NUM> to the LMF <NUM>. A location response from the LMF <NUM> (e.g., containing a location estimate for the UE <NUM>) may be similarly returned to the GMLC <NUM> either directly or via the AMF <NUM>, and the GMLC <NUM> may then return the location response (e.g., containing the location estimate) to the external client <NUM>.

A Network Exposure Function (NEF) <NUM> may be included in 5GCN <NUM>. The NEF <NUM> may support secure exposure of capabilities and events concerning 5GCN <NUM> and UE <NUM> to the external client <NUM>, which may then be referred to as an Access Function (AF) and may enable secure provision of information from external client <NUM> to 5GCN <NUM>. NEF <NUM> may be connected to AMF <NUM> and/or to GMLC <NUM> for the purposes of obtaining a location (e.g. a civic location) of UE <NUM> and providing the location to external client <NUM>.

As further illustrated in <FIG>, the LMF <NUM> may communicate with the gNBs <NUM> and/or with the ng-eNB <NUM> using an NR Positioning Protocol annex (NRPPa) as defined in 3GPP Technical Specification (TS) <NUM>. NRPPa messages may be transferred between a gNB <NUM> and the LMF <NUM>, and/or between an ng-eNB <NUM> and the LMF <NUM>, via the AMF <NUM>. As further illustrated in <FIG>, LMF <NUM> and UE <NUM> may communicate using an LTE Positioning Protocol (LPP) as defined in 3GPP TS <NUM>. Here, LPP messages may be transferred between the UE <NUM> and the LMF <NUM> via the AMF <NUM> and a serving gNB <NUM>-<NUM> or serving ng-eNB <NUM> for UE <NUM>. For example, LPP messages may be transferred between the LMF <NUM> and the AMF <NUM> using messages for service-based operations (e.g., based on the Hypertext Transfer Protocol (HTTP)) and may be transferred between the AMF <NUM> and the UE <NUM> using a <NUM> NAS protocol. The LPP protocol may be used to support positioning of UE <NUM> using UE assisted and/or UE based position methods such as A-GNSS, RTK, TDOA, multi-cell RTT, AoD, and/or ECID. The NRPPa protocol may be used to support positioning of UE <NUM> using network based position methods such as ECID, AoA, uplink TDOA (UL-TDOA) and/or may be used by LMF <NUM> to obtain location related information from gNBs <NUM> and/or ng-eNB <NUM>, such as parameters defining DL-PRS transmission from gNBs <NUM> and/or ng-eNB <NUM>.

In the case of UE <NUM> access to WLAN <NUM>, LMF <NUM> may use NRPPa and/or LPP to obtain a location of UE <NUM> in a similar manner to that just described for UE <NUM> access to a gNB <NUM> or ng-eNB <NUM>. Thus, NRPPa messages may be transferred between a WLAN <NUM> and the LMF <NUM>, via the AMF <NUM> and N3IWF <NUM> to support network-based positioning of UE <NUM> and/or transfer of other location information from WLAN <NUM> to LMF <NUM>. Alternatively, NRPPa messages may be transferred between N3IWF <NUM> and the LMF <NUM>, via the AMF <NUM>, to support network-based positioning of UE <NUM> based on location related information and/or location measurements known to or accessible to N3IWF <NUM> and transferred from N3IWF <NUM> to LMF <NUM> using NRPPa. Similarly, LPP and/or LPP messages may be transferred between the UE <NUM> and the LMF <NUM> via the AMF <NUM>, N3IWF <NUM>, and serving WLAN <NUM> for UE <NUM> to support UE assisted or UE based positioning of UE <NUM> by LMF <NUM>.

In a <NUM> NR positioning system <NUM>, positioning methods can be categorized as being "UE assisted" or "UE based. " This may depend on where the request for determining the position of the UE <NUM> originated. If, for example, the request originated at the UE (e.g., from an application, or "app," executed by the UE), the positioning method may be categorized as being UE based. If, on the other hand, the request originates from an external client or AF <NUM>, LMF <NUM>, or other device or service within the <NUM> network, the positioning method may be categorized as being UE assisted (or "network-based").

With a UE-assisted position method, UE <NUM> may obtain location measurements and send the measurements to a location server (e.g., LMF <NUM>) for computation of a location estimate for UE <NUM>. For RAT-dependent position methods location measurements may include one or more of a Received Signal Strength Indicator (RSSI), RTT, Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Reference Signal Time Difference (RSTD), Time of Arrival (TOA), AoA, Receive Time-Transmission Time Difference (Rx-Tx), Differential AoA (DAoA), AoD, or Timing Advance (TA) for gNBs <NUM>, ng-eNB <NUM>, and/or one or more access points for WLAN <NUM>. Additionally or alternatively, similar measurements may be made of sidelink signals transmitted by other UEs, which may serve as anchor points for positioning of the UE <NUM> if the positions of the other UEs are known. The location measurements may also or instead include measurements for RAT-independent positioning methods such as GNSS (e.g., GNSS pseudorange, GNSS code phase, and/or GNSS carrier phase for GNSS satellites <NUM>), WLAN, etc..

With a UE-based position method, UE <NUM> may obtain location measurements (e.g., which may be the same as or similar to location measurements for a UE assisted position method) and may further compute a location of UE <NUM> (e.g., with the help of assistance data received from a location server such as LMF <NUM>, an SLP, or broadcast by gNBs <NUM>, ng-eNB <NUM>, or WLAN <NUM>).

With a network based position method, one or more base stations (e.g., gNBs <NUM> and/or ng-eNB <NUM>), one or more APs (e.g., in WLAN <NUM>), or N3IWF <NUM> may obtain location measurements (e.g., measurements of RSSI, RTT, RSRP, RSRQ, AoA, or TOA) for signals transmitted by UE <NUM>, and/or may receive measurements obtained by UE <NUM> or by an AP in WLAN <NUM> in the case of N3IWF <NUM>, and may send the measurements to a location server (e.g., LMF <NUM>) for computation of a location estimate for UE <NUM>.

Positioning of the UE <NUM> also may be categorized as UL, DL, or DL-UL based, depending on the types of signals used for positioning. If, for example, positioning is based solely on signals received at the UE <NUM> (e.g., from a base station or other UE), the positioning may be categorized as DL based. On the other hand, if positioning is based solely on signals transmitted by the UE <NUM> (which may be received by a base station or other UE, for example), the positioning may be categorized as UL based. Positioning that is DL-UL based includes positioning, such as RTT-based positioning, that is based on signals that are both transmitted and received by the UE <NUM>. Sidelink (SL)-assisted positioning comprises signals communicated between the UE <NUM> and one or more other UEs. According to some embodiments, UL, DL, or DL-UL positioning as described herein may be capable of using SL signaling as a complement or replacement of SL, DL, or DL-UL signaling.

Depending on the type of positioning (e.g., UL, DL, or DL-UL based) the types of reference signals used can vary. For DL-based positioning, for example, these signals may comprise PRS (e.g., DL-PRS transmitted by base stations or SL-PRS transmitted by other UEs), which can be used for TDOA, AoD, and RTT measurements. Other reference signals that can be used for positioning (UL, DL, or DL-UL) may include Sounding Reference Signal (SRS), Channel State Information Reference Signal (CSI-RS), synchronization signals (e.g., synchronization signal block (SSB) Synchronizations Signal (SS)), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Physical Sidelink Shared Channel (PSSCH), Demodulation Reference Signal (DMRS), etc. Moreover, reference signals may be transmitted in a Tx beam and/or received in an Rx beam (e.g., using beamforming techniques), which may impact angular measurements, such as AoD and/or AoA.

Referring now to <FIG> illustrates an example system <NUM> for bi-static radio-based object location detection. The system <NUM> this example includes a wireless base station <NUM> (e.g., a base station <NUM> of <FIG> and/or gNB <NUM> or ng-eNB <NUM> of <FIG>) and a user device <NUM> (e.g., a UE <NUM> of <FIG> and/or <NUM>), each of which may be referred to as a "wireless device. " In addition, an object <NUM> is in the environment served by the base station <NUM>. In this example, the base station <NUM> and the user device <NUM> communicate using <NUM> frequency bands (e.g., <NUM>). However, other millimeter-wave (or "mmWave") radio frequencies may be used as well, including frequencies ranging from <NUM>-<NUM>, which includes, for example, frequencies utilized by the <NUM>. 11ad Wi-Fi standard (operating at <NUM>). Because positioning functionality according to this disclosure may be performed in the same frequency bands as communication, hardware may be utilized for both communication and location sensing. For example, one or more of the components of the system <NUM> shown in <FIG> may employ a wireless modem (e.g., Wi-Fi or <NUM> modem).

In this example, the base station <NUM> is a <NUM> wireless base station as discussed above with respect to <FIG>, but in other examples, the base station <NUM> may be any suitable wireless access point to a network, such as a Wi-Fi access point. Similarly, the user device <NUM> depicted in <FIG> is a <NUM> wireless device, but in other examples may employ any suitable wireless communications technology, including Wi-Fi. For example, hardware to enable functionality described in this disclosure may be integrated into mobile phones as well as many other types of devices or vehicles. These can include, for example, other mobile devices (e.g., tablets, portable media players, laptops, wearable devices, virtual reality (VR) devices, augmented reality (AR) devices), as well as other electronic devices (e.g., security devices, on-vehicle systems). That said, electronic devices are not limited to mobile devices and instead may be integrated into fixed wireless stations, and as such may be installed in or on a building or other structure.

One of the advantages of using wireless technology in some examples is that existing wireless devices can be used to perform object location detection. For example, a conventional wireless network, e.g., a <NUM> wireless network, could implement software to perform the functionality described herein using existing infrastructure. Any suitable wireless signal could be used as the reference signal discussed herein. Similarly, Wi-Fi or other access-point-based communication networking modalities may be used in some examples. Such access points or base stations can coordinate with other wireless devices to detect objects in the environment and determine their locations.

<FIG> illustrates the use of techniques according to this disclosure to determine the location of the object <NUM> in the environment served by the base station <NUM>. When the base station <NUM> and user device <NUM> communicate, they each transmit radio signals that propagate through the environment and arrive at the other device. In an idealized environment that only includes the user device <NUM> and the base station <NUM>, the wireless signals will traverse a direct path <NUM> between the two devices <NUM>, <NUM>; however, in reality, transmitted wireless signals may also reflect off of other objects in the area resulting in potentially many reflected versions of the signal arriving at the receiver's antenna(s). For example, a base station <NUM> that uses an omnidirectional transmitter will transmit signals in multiple directions at the same time. As these signals propagate, they may encounter objects and reflect off of them, ultimately arriving at the receiver's antenna. This propagation of multiple versions of the same signal, e.g., due to reflection, is generally referred to as "multipath. " Examples according to this disclosure take advantage of such multipath signal propagation as will be discussed in more detail below.

In addition to such omnidirectional transmission, some base stations <NUM> may employ beamforming to transmit signals into an environment. For example, a base station may sweep a beam across an arc, e.g., <NUM>-degrees, <NUM>-degrees, etc. through an environment to transmit signals. Thus, as the base station <NUM> sweeps the signal through the environment, at some time, it will be directed at the receiver's antenna, which receives it via a direct transmission path. At other times, the beam may be reflected by objects in the environment and ultimately arrive at the receiver's antenna via the reflected path. While the two different signals will have many of the same characteristics, such as data encoded on the beam, they will have been transmitted at different times and thus may be considered separate signals, despite both being conceptually the same signal. However, techniques according to this disclosure may employ either omnidirectional or beamformed signal transmissions.

In this example, the environment includes the base station <NUM> and the user device <NUM> and the object <NUM>. Thus, as transmitted signals propagate between the base station <NUM> and the user device <NUM> some signals are received via the direct path <NUM> and some via a reflected path 342a-b off of the object <NUM>. By determining signal characteristics of each type of received signal-direct-path and reflected-path-and by knowing the location (XBS, YBS) or (XUD, YUD) of one or both wireless devices <NUM>, <NUM>, the location (XO, YO) of the object <NUM> can be determined.

Referring now to <FIG> illustrates an ellipse <NUM> and corresponding ellipse information that can be used to locate an object at an arbitrary point on the ellipse <NUM>, so long as certain information is known. An ellipse is defined by two focus points, F<NUM> and F<NUM>, a semi-major axis, a, and a semi-minor axis, b. The ellipse then includes all of the points having the same sum of distances, |PF<NUM>| + |PF<NUM>|, relative to focus points, F<NUM> and F<NUM>. In the system <NUM> shown in <FIG>, an ellipse may be determined by setting the base station <NUM> and user device <NUM> as the focus points and using ToF information for reflected signals from an object <NUM>. For example, a time-of-flight measurement between a transmit antenna array (e.g., base station <NUM>) located at F<NUM> and an receiver antenna array (e.g., user device <NUM>) located at F<NUM>, in which the wireless signal reflected off of an object <NUM> at point P would correspond to a distance measurement of |PF<NUM>| + [PF<NUM>|. An ellipse can then be calculated using the two focus points and the distance measurement (as discussed above), and a location of the object can be estimated based on the geometry of the ellipse and the determined signal characteristics.

For example, according to some examples in which a system for bi-static radio-based object location detection detects an object, the object can be assumed to be on the ground or in substantially the same horizontal plane as both the base station <NUM> and user device <NUM>. (It can be noted that in some examples, antenna elements may be offset from the coordinate system used to establish azimuth and elevation. In such examples, the determination of the ellipse and the distance can account for this offset.

<FIG> illustrates how the geometry of an ellipse can be leveraged to determine a location of an object, e.g., object <NUM>. As discussed above, a wireless device determines both a ToF and an AoA for received signals, e.g., wireless signals following the reflected path 342a-b. Thus, depending on which wireless device <NUM>, <NUM> receives the reflected signal 342a-b, the AoA will correspond to one of θ<NUM> or θ<NUM>. The location of the object can then be calculated based on the properties of the ellipse. First, the semi-major and semi-minor axis lengths may be determined with the following equations: <MAT> and <MAT>.

Then the ellipse itself can be calculated as follows: <MAT>.

Equation (<NUM>) assumes that the center of the ellipse (the point that is collinear with and equidistant between the focus points, F<NUM> and F<NUM>) is (<NUM>, <NUM>), which can be used for calculation purposes before mapping the ellipse onto another coordinate system, e.g., based on latitude and longitude.

Once the shape of the ellipse is known, the location of the object may be determined based on the determined AoA at the respective device, either θ<NUM> or θ<NUM>. The corresponding point, P, on the ellipse is the location of the object. For example, a ray originating at one of the focus points and projected at the AoA will intersect with the ellipse at the location of the object, represented by point, P. Thus, by finding the point of intersection between the ray and the ellipse, the location of the object may be determined.

Alternatively, the ellipse may be defined using polar coordinates relative to one of the two focus points, which may provide another way to determine the location of an arbitrary point on the ellipse, given the AoA. The two axes are determined as discussed above with respect to equations (<NUM>) and (<NUM>). Next, the eccentricity of the ellipse is determined by: <MAT>.

Finally, the ellipse may be calculated based on a focus and an angle, θ: <MAT>.

Thus, using the ellipse and the known AoA, the location of the object may be determined.

<FIG> is a diagram of an example system <NUM> for bi-static radio-based object location detection. The system <NUM> is attempting to determine the location of the target <NUM> according to the disclosed techniques herein. As discussed above, the base station <NUM> and the user device <NUM> communicate using RF signals that traverse the environment around the user device <NUM> and the base station <NUM>. (Again, the base station <NUM> and user device <NUM> may correspond with base stations and/or user devices/mobile devices as described previously. ) Ideally, the signals would traverse a direct path <NUM> between the base station <NUM> and the user device <NUM>, however, some signal reflection does occur, resulting in multiple copies of the same signal arriving at the receiving device at different times.

In this example, one of the two wireless devices, i.e., the base station <NUM> and the user device <NUM>, attempts to determine the location of one or more objects in the environment. For purposes of this example, the base station <NUM> attempts to determine the location of the target <NUM>, though it could also be done by the user device <NUM>. The base station <NUM> begins by determining its location and the location of the user device <NUM>, e.g., by requesting the location from the user device <NUM> or by determining the user device's location, e.g., by using RTT and AoA techniques to determine a distance and heading to the user device <NUM>.

The base station <NUM> then transmits a reference signal to the other device. The reference signal is any suitable signal transmitted using the available RF bandwidth that is used to help determine the location of the target <NUM>. For example, the reference signal may be sent using a beamforming technique to direct a reference signal to the remote device. In some examples, the reference signal may transmit omnidirectionally. In such an example, while many copies of the reference signal may arrive at the user device <NUM>, the first one to arrive may be identified as having taken the most direct path, illustrated as the idealized straight-line direct path <NUM> in <FIG>.

The user device <NUM> then receives a reflected version of the reference signal that has encountered the target while propagating through the environment. In examples where the reference signal is transmitted using a beamforming technique, the reflected version of the reference signal may be a signal transmitted at a different time than the beamformed signal transmitted to the remote device. For example, the transmitter may direct a beam at a target object in an environment and the remote device may detect a reflection of the beam off of the target object. In some examples where the transmitter transmits the reference signal omnidirectionally, the reflected signal may have been transmitted at the same time as the signal traversing a direct path <NUM> from the transmitter to the remove device. In either case, the reflected signal follows the paths 542a-b shown in <FIG>. The user device <NUM> then computes the ToF and the AoA, i.e., φ(UD, Target) for the reflected signal using conventional wireless signal processing techniques.

After computing these two parameters, the user device <NUM> then communicates them to the base station <NUM>, which receives them and determines the location of the target. First, it determines the shape of an ellipse based on the ToF for the reflected path 542a-b as described above with respect to <FIG>. Because all points on an ellipse have the same combined distance to each of the two focus points, a single ellipse is defined based on the ToF. This is because the ToF represents the distance travelled by the reference signal from the base station <NUM> to the user device <NUM> as it reflected off of the target <NUM>.

In addition, based on the AoA of the reflected signal at the user device <NUM>, a single point on the ellipse can be identified by extending a ray outward from the user device <NUM> at the AoA of the reflected signal. The point at which the ray intersects the ellipse represents the location of the target <NUM>. For example, as illustrated above with equation <NUM>, once various properties of the ellipse are known, a point on the ellipse may be determined based on the location of a focus point and an angle from that focus point. The location on the ellipse may then be mapped to a geographical coordinate system, such as latitude and longitude, to obtain the location of the target <NUM>.

As mentioned above, while the base station <NUM> initiated the positioning functionality and transmitted the reference signal, in some examples, the user device <NUM> may perform either or both of such functionalities. Further, while the user device <NUM> received the reference signal and computed the ToF and AoA parameters, such parameters may instead be determined by the base station <NUM>. Further, either the base station <NUM> or the user device <NUM> may determine the location of the target based on the determined ToF and AoA parameters.

<FIG> is a flow chart of a method <NUM> for bi-static radio-based object location detection, according to an embodiment. This example method <NUM> will be discussed with respect to the example system <NUM> shown in <FIG>, though it may be performed by any system according to this disclosure. For example, some or all of the operations illustrated in method <NUM> may be performed by a base station <NUM> (e.g., base station <NUM>) or UE <NUM> (e.g., user device <NUM>). Example hardware and/or software components that may be used to perform these operations by a base station <NUM> or UE <NUM> are provided in <FIG> and <FIG>, respectively, which are discussed in more detail hereafter.

The functionality at block <NUM> comprises obtaining, at a first wireless device, a location of a second wireless device. As noted below with regard to block <NUM>, the first wireless device may be the transmitting device and the second wireless device may be the receiving device, or vice versa. In an example, the first wireless device may use any of the positioning techniques discussed above with respect to <FIG> and <FIG> to obtain the location of the second wireless device. Additionally or alternatively, the method <NUM> may comprise requesting, by the first wireless device from the second wireless device, the location of the second wireless device, wherein obtaining the location of the second wireless device may comprises receiving the location of the second wireless device by the first wireless device from the second wireless device. For example, the second wireless device may comprise a user device that determines its own location, such as by using a suitable GNSS, such as GPS, or by using RF techniques, such as trilateration based on received wireless signals, Wi-Fi (or other WLAN) positioning, etc. However, in some examples, the first wireless device may comprise a base station <NUM> that may obtain the location of the second wireless device (user device <NUM>) based on determining a RTT of a signal, such as a reference signal, transmitted by the base station <NUM> and a corresponding response sent by the user device <NUM>, as well as an AoA of the response received by the base station <NUM>. The RTT indicates the ToF from the base station <NUM> to the user device <NUM> and the ToF from the user device to the base station <NUM> (plus some processing time at the user device <NUM>). Thus, the RTT gives a close approximation of the distance between the base station and the user device, e.g., (RTT/<NUM>) * c, where c is the speed of light. In addition, by determining the AoA of the user device's response, the base station <NUM> determines a heading to the user device <NUM>. Thus, the base station can compute the user device's position based on the base station's position, the distance to the user device, and the heading to the user device.

While the example above contemplated the base station <NUM> obtaining the location of the user device <NUM>, in some examples, the user device <NUM> may instead obtain the location of the base station <NUM>. For example, the user device <NUM> may request the base station's location from the base station <NUM>, or it may obtain the base station's location based on the RTT and AoA techniques discussed above, or any other suitable technique. Thus, the first wireless device and second wireless device of the method <NUM> each correspond to a base station <NUM> and user device <NUM>, respectively, or vice versa. That is, according to some embodiments of the method <NUM>, the first wireless device comprises a first base station and the second wireless device comprises a second base station or a wireless user device. Alternatively, according to some embodiments, the first wireless device comprises a first wireless user device and the second wireless device comprises a second wireless user device or a base station.

Further suitable means for determining a location of a second wireless device include software executed by a processor that is configured to determine RTT and AoA as discussed above. In some examples, suitable means for obtaining a location of a second wireless device include a radio transceiver and an antenna to transmit a signal to the second wireless device and to receive the response from the second wireless device indicating the location of the second wireless device, as discussed above. However, any suitable means for determining a location of a second wireless device may be employed according to this disclosure.

At block <NUM>, the functionality comprises obtaining, at the first wireless device, a ToF and an AoA of a wireless WWAN reference signal transmitted by a transmitting device, wherein TOF and AoA are obtained from measurements of the WWAN reference signal at a receiving device after the WWAN reference signal is reflected by an object. According to some embodiments, the first wireless device may transmit a reference signal, as discussed above with respect to <FIG>, to the second wireless device, which reflects off of the target <NUM>. The second wireless device may then receive the reflected version of the signal and, based on determining that the received signal is a reference signal for object location detection, it may determine the ToF and AoA for the reflected version of the signal, which corresponds to the reference signal following the reflected path 542a-b. It should be appreciated that in some examples, the AoA of the reflected reference signal may be determined with respect to the AoA of the direct transmission path <NUM>. That is, the AoA of the WWAN reference signal at block <NUM> of <FIG> may comprise a DAoA indicative of an angle between a reflected path of the WWAN reference signal and a direct path between the first wireless device and the second wireless device. However, in some examples, the AoA of the reflected reference signal may be determined without reference to the AoA of the direct transmission path. According to some embodiments, the first device may transmit the WWAN reference signal using a first beam and a second beam. In such embodiments, the WWAN reference signal transmitted using the first beam May travel a direct path to the second device, and the WWAN reference signal transmitted using the second beam may be reflected by the object.

In some examples, the first wireless device itself may determine the ToF and AoA to obtain those parameters. For example, a first wireless device comprising a base station <NUM> may, rather than transmitting a reference signal to the second wireless device (e.g., user device <NUM>), receive a reference signal transmitted by the second wireless device. In response to receiving one or more reflected versions of the reference signal, the first wireless device may determine the ToF and AoA of the received reflected reference signal to obtain those parameters.

With this in mind, and as described in more detail below, various of the method <NUM> may occur. For example, according to some embodiments, the first device comprises the transmitting device and the second device comprises the receiving device, and obtaining the ToF and the AoA of the WWAN reference signal comprises receiving, at the first wireless device, signal information from the second wireless device, the signal information comprising an indication of the ToF and an indication of the AoA of the WWAN reference signal. According to some embodiments, the first device comprises the receiving device and the second device comprises the transmitting device, and obtaining the ToF and the AoA of the WWAN reference signal comprises taking measurements of the WWAN reference signal by the first device to obtain the ToF and the AoA.

Suitable means for obtaining ToF and AoA parameters of a reflected reference signal include a radio receiver and antenna. As discussed above, obtaining ToF and AoA parameters may include transmitting a signal to a remote wireless device and receiving a response including indications of the ToF and AoA parameters. In some examples, means for obtaining may include (or may be) means for determining ToF and AoA of a received wireless signal may include a radio receiver and antenna and software to determine a time-difference of arrival of the signal at different elements of the antenna, e.g., based on phase differences of signals received at antenna elements. Further, software may determine ToF based on synchronized clocks or time bases at the transmitting device and the receiving device as well as on a transmission scheme where transmission of certain signals occur at certain predetermined time within the transmission scheme. ToF may represent a measurable offset or delay from the predetermined transmit time by the receiver. However, any suitable means for obtaining a reflected ToF and an AoA of a WWAN reference signal reflected by a remote object or means for determining a reflected ToF and an AoA of a WWAN reference signal reflected by a remote object may be employed according to this disclosure.

At block <NUM> the functionality comprises determining, with the first wireless device, a location of the object based on the location of the second wireless device, the ToF, and the AoA, where (i) the first device comprises the transmitting device and the second device comprises the receiving device, or (ii) the first device comprises the receiving device and the second device comprises the transmitting device. In this example, the first wireless device may determine the location of the remote object based on an ellipse generated from the reflected ToF. As discussed above with respect to <FIG> and <FIG>, an ellipse may be determined based on the reflected ToF and one or both of the locations of the wireless device and the remote wireless device. After generating the ellipse, the first wireless device (e.g., base station <NUM>) may determine an intersection between a ray extending from the second wireless device's location (e.g., user device's location <NUM>) at the AoA and the ellipse. The location of the intersection indicates the location of the remote object, e.g., target <NUM>. In some examples, the first wireless device may employ one or more of equations <NUM>-<NUM> to determine the intersection between the ray and the ellipse.

In some examples, the first wireless device may employ a geographic coordinate system, e.g., when defining the ellipse. Thus, when the first wireless device first wireless device determines the location of the intersection between the ray and the ellipse, the location may be represented by a further geographic coordinate. However, in examples where the first wireless device uses a different coordinate system, e.g., where the ellipse is centered on a hypothetical origin point having coordinates (<NUM>,<NUM>), the first wireless device may then map the ellipse from the hypothetical coordinate system to another coordinate system, e.g., an absolute coordinate system such as latitude and longitude. The mapping may be performed by calculating offsets from the hypothetical coordinate system to coordinates in the other coordinate system, e.g., for the locations of the first wireless device and the second wireless device. Such offsets may then be applied to the coordinates of the intersection point between the ray and the ellipse. And while this example involved the first wireless device determining the location of the remote object, it should be appreciated that in some examples, the second wireless device may determine the location of the remote object. Suitable means for determining a location of the remote object based on the location of the remote wireless device may include software or hardware programmed to perform the functionality discussed above with respect to block <NUM> as well as <FIG> and <FIG> to generate an ellipse and determine an intersection between a ray extending from the remote wireless device at the AoA and the ellipse.

While the example method <NUM> shown in <FIG> was described above as being performed by a first wireless device comprising a base station <NUM> based on information received from a second wireless device comprising the user device <NUM>, it should be appreciated that the base station <NUM> and user device <NUM> each may perform the functionality of the first or second wireless device of method <NUM>. Further, it should be appreciated that in some examples, ToF and AoA information may be determined by the remote wireless device and obtained by the wireless device, or the wireless device may receive a reference signal from the remote wireless device and determine the ToF and AoA locally. Thus, there are at least four different permutations of the method <NUM> discussed above. First, the base station <NUM> comprises the first wireless device that performs the method <NUM> and transmits a reference signal to a user device <NUM> that comprises the second wireless device, which responds with ToF and AoA information. Second, the base station <NUM> comprises the first wireless device that performs the method <NUM>, receives a reference signal from the user device <NUM> that comprises the second wireless device, and determines the ToF and AoA information and the location of the remote object. Third, the user device <NUM> comprises the first wireless device that performs the method and transmits a reference signal to the base station <NUM> comprising the second wireless device, which responds with ToF and AoA information. Fourth, the user device <NUM> comprises the first wireless device that performs the method <NUM>, receives a reference signal from the base station <NUM> comprising the second wireless device, and determines the ToF and AoA information and the location of the remote object. These variants are illustrated and described below with respect to <FIG>.

<FIG> is a flow diagram another example method <NUM> for bi-static radio-based object location detection. This example method <NUM> will be discussed with respect to the example system <NUM> shown in <FIG>, though it may be performed by any system according to this disclosure. The method of <FIG> illustrates an example method where the device that determines the location of a remote object transmits a reference signal to a remote wireless device to receive signal characteristics of the reference signal as reflected from the remote object, including ToF and AoA.

At block <NUM>, a wireless device obtains a location of a remote wireless device, generally as discussed above with respect to block <NUM>. For example, the base station <NUM> may determine the location of the user device <NUM>, or the user device <NUM> may determine the location of the base station <NUM>.

At block <NUM>, the wireless device transmits a reference signal to the remote wireless device. As discussed above, either the base station <NUM> or the user device <NUM> may transmit the reference signal. Further, any suitable reference signal may be employed. For example, an existing signal defined by a wireless specification may be employed or a distinct signal defined specifically as a reference signal for bi-static radio-based object location detection may be employed. Means for transmitting the reference signal may include a radio transmitter and antenna. Further, in some examples, the means may include software or hardware programmed to generate suitable information to be encoded onto a radio wave according to the definition of the reference signal by the corresponding specification.

At block <NUM>, the wireless device receives an indication ToF and an AoA of the reference signal reflected by a remote object substantially as discussed above with respect to block <NUM>.

At block <NUM>, the wireless device determines the location of the remote object substantially as discussed above with respect to block <NUM>.

Referring now to <FIG> shows another example method <NUM> for bi-static radio-based object location detection. This example method <NUM> will be discussed with respect to the example system <NUM> shown in <FIG>, though it may be performed by any system according to this disclosure. The method of <FIG> illustrates an example method where the device that determines the location of a remote object receives a reference signal from a remote wireless device and determines signal characteristics of the reference signal as reflected from the remote object, including the ToF and AoA.

At block <NUM>, the wireless device receives a reference signal from the remote wireless device. As discussed above, either the base station <NUM> or the user device <NUM> may receive the reference signal. Further, any suitable reference signal may be employed as discussed above with respect to block <NUM>. Means for receiving the reference signal may include a radio receiver and antenna. Further, in some examples, the means may include software or hardware programmed to decode the received reference signal according to the definition of the reference signal by the corresponding specification.

At block <NUM>, the wireless device determines the ToF and the AoA of the reference signal reflected by a remote object substantially as discussed above with respect to block <NUM>.

<FIG> illustrates an example of a UE <NUM>, which can be utilized as described herein above (e.g., in association with <FIG>). For example, the UE <NUM> can perform one or more of the functions of the method shown in <FIG>. It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate. It can be noted that, in some instances, components illustrated by <FIG> can be localized to a single physical device and/or distributed among various networked devices, which may be disposed at different physical locations. Furthermore, as previously noted, the functionality of the UE described in the previously-described examples may be executed by one or more of the hardware and/or software components illustrated in <FIG>.

The UE <NUM> is shown comprising hardware elements that can be electrically coupled via a bus <NUM> (or may otherwise be in communication, as appropriate). The hardware elements may include a processing unit(s) <NUM> which can include without limitation one or more general-purpose processors, one or more special-purpose processors (such as DSP chips, graphics acceleration processors, application specific integrated circuits (ASICs), and/or the like), and/or other processing structures or means. As shown in <FIG>, some examples may have a separate DSP <NUM>, depending on desired functionality. Location determination and/or other determinations based on wireless communication may be provided in the processing unit(s) <NUM> and/or wireless communication interface <NUM> (discussed below). The UE <NUM> also can include one or more input devices <NUM>, which can include without limitation a keyboard, touch screen, a touch pad, microphone, button(s), dial(s), switch(es), and/or the like; and one or more output devices <NUM>, which can include without limitation a display, light emitting diode (LED), speakers, and/or the like.

The UE <NUM> may also include a wireless communication interface <NUM>, which may comprise without limitation a modem, a network card, an infrared communication device, a wireless communication device, and/or a chipset (such as a Bluetooth® device, an IEEE <NUM> device, an IEEE <NUM>. <NUM> device, a Wi-Fi device, a WiMAX device, a WAN device, and/or various cellular devices, etc.), and/or the like, which may enable the UE <NUM> to communicate with other devices as described in the examples above. The wireless communication interface <NUM> may permit data and signaling to be communicated (e.g., transmitted and received) with a network, for example, via eNBs, gNBs, ng-eNBs, access points, various base stations and/or other access node types, TRPs, and/or other network components, computer systems, and/or any other electronic devices described herein. The communication can be carried out via one or more wireless communication antenna(s) <NUM> that send and/or receive wireless signals <NUM>. According to some examples, the wireless communication antenna(s) <NUM> may comprise a plurality of discrete antennas, antenna arrays, or any combination thereof.

Depending on desired functionality, the wireless communication interface <NUM> may comprise a separate receiver and transmitter, or any combination of transceivers, transmitters, and/or receivers to communicate with base stations (e.g., ng-eNBs and gNBs) and other terrestrial transceivers, such as wireless devices and access points. The UE <NUM> may communicate with different data networks that may comprise various network types. For example, a Wireless Wide Area Network (WWAN) may be a CDMA network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) network, a WiMAX (IEEE <NUM>) network, and so on. A CDMA network may implement one or more RATs such as CDMA2000, WCDMA, and so on. CDMA2000 includes IS-<NUM>, IS-<NUM> and/or IS-<NUM> standards. A TDMA network may implement GSM, Digital Advanced Mobile Phone System (D-AMPS), or some other RAT. An OFDMA network may employ LTE, LTE Advanced, <NUM> NR, and so on. <NUM> NR, LTE, LTE Advanced, GSM, and WCDMA are described in documents from 3GPP. CDMA2000 is described in documents from a consortium named "3rd Generation Partnership Project <NUM>" (3GPP2). 3GPP and 3GPP2 documents are publicly available. A wireless local area network (WLAN) may also be an IEEE <NUM>. 11x network, and a wireless personal area network (WPAN) may be a Bluetooth network, an IEEE <NUM>. 15x, or some other type of network. The techniques described herein may also be used for any combination of WWAN, WLAN and/or WPAN.

The UE <NUM> can further include sensor(s) <NUM>. Sensors <NUM> may comprise, without limitation, one or more inertial sensors and/or other sensors (e.g., accelerometer(s), gyroscope(s), camera(s), magnetometer(s), altimeter(s), microphone(s), proximity sensor(s), light sensor(s), barometer(s), and the like), some of which may be used to obtain position-related measurements and/or other information, as described herein.

Examples of the UE <NUM> may also include a Global Navigation Satellite System (GNSS) receiver <NUM> capable of receiving signals <NUM> from one or more GNSS satellites using an antenna <NUM> (which could be the same as antenna <NUM>). Positioning based on GNSS signal measurement can be utilized to complement and/or incorporate the techniques described herein. The GNSS receiver <NUM> can extract a position of the UE <NUM>, using conventional techniques, from GNSS SVs <NUM> of a GNSS system, such as Global Positioning System (GPS), Galileo, GLONASS, Quasi-Zenith Satellite System (QZSS) over Japan, Indian Regional Navigational Satellite System (IRNSS) over India, Beidou over China, and/or the like. Moreover, the GNSS receiver <NUM> can be used with various augmentation systems (e.g., a Satellite Based Augmentation System (SBAS)) that may be associated with or otherwise enabled for use with one or more global and/or regional navigation satellite systems, such as, e.g., WAAS, EGNOS, Multi-functional Satellite Augmentation System (MSAS), and Geo Augmented Navigation system (GAGAN), and/or the like.

The UE <NUM> may further include and/or be in communication with a memory <NUM>. The memory <NUM> can include, without limitation, local and/or network accessible storage, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a random access memory (RAM), and/or a read-only memory (ROM), which can be programmable, flash-updateable, and/or the like. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like.

The memory <NUM> of the UE <NUM> also can comprise software elements (not shown in <FIG>), including an operating system, device drivers, executable libraries, and/or other code, such as one or more application programs, which may comprise computer programs provided by various examples, and/or may be designed to implement methods, and/or configure systems, provided by other examples, as described herein. Merely by way of example, one or more procedures described with respect to the method(s) discussed above may be implemented as code and/or instructions in memory <NUM> that are executable by the UE <NUM> (and/or processing unit(s) <NUM> or DSP <NUM> within UE <NUM>). In an aspect, then such code and/or instructions can be used to configure and/or adapt a general purpose computer (or other device) to perform one or more operations in accordance with the described methods.

<FIG> illustrates an example of a base station <NUM>, which can be utilized as described herein above (e.g., in association with <FIG>). It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate. In some examples, the base station <NUM> may correspond to a gNB, an ng-eNB, and/or (more generally) a TRP.

The base station <NUM> is shown comprising hardware elements that can be electrically coupled via a bus <NUM> (or may otherwise be in communication, as appropriate). The hardware elements may include a processing unit(s) <NUM> which can include without limitation one or more general-purpose processors, one or more special-purpose processors (such as DSP chips, graphics acceleration processors, ASICs, and/or the like), and/or other processing structure or means. As shown in <FIG>, some examples may have a separate DSP <NUM>, depending on desired functionality. Location determination and/or other determinations based on wireless communication may be provided in the processing unit(s) <NUM> and/or wireless communication interface <NUM> (discussed below), according to some examples. The base station <NUM> also can include one or more input devices, which can include without limitation a keyboard, display, mouse, microphone, button(s), dial(s), switch(es), and/or the like; and one or more output devices, which can include without limitation a display, light emitting diode (LED), speakers, and/or the like.

The base station <NUM> might also include a wireless communication interface <NUM>, which may comprise without limitation a modem, a network card, an infrared communication device, a wireless communication device, and/or a chipset (such as a Bluetooth® device, an IEEE <NUM> device, an IEEE <NUM>. <NUM> device, a Wi-Fi device, a WiMAX device, cellular communication facilities, etc.), and/or the like, which may enable the base station <NUM> to communicate as described herein. The wireless communication interface <NUM> may permit data and signaling to be communicated (e.g., transmitted and received) to UEs, other base stations/TRPs (e.g., eNBs, gNBs, and ng-eNBs), and/or other network components, computer systems, and/or any other electronic devices described herein. The communication can be carried out via one or more wireless communication antenna(s) <NUM> that send and/or receive wireless signals <NUM>.

The base station <NUM> may also include a network interface <NUM>, which can include support of wireline communication technologies. The network interface <NUM> may include a modem, network card, chipset, and/or the like. The network interface <NUM> may include one or more input and/or output communication interfaces to permit data to be exchanged with a network, communication network servers, computer systems, and/or any other electronic devices described herein.

In many examples, the base station <NUM> may further comprise a memory <NUM>. The memory <NUM> can include, without limitation, local and/or network accessible storage, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a RAM, and/or a ROM, which can be programmable, flash-updateable, and/or the like. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like.

The memory <NUM> of the base station <NUM> also may comprise software elements (not shown in <FIG>), including an operating system, device drivers, executable libraries, and/or other code, such as one or more application programs, which may comprise computer programs provided by various examples, and/or may be designed to implement methods, and/or configure systems, provided by other examples, as described herein. Merely by way of example, one or more procedures described with respect to the method(s) discussed above may be implemented as code and/or instructions in memory <NUM> that are executable by the base station <NUM> (and/or processing unit(s) <NUM> or DSP <NUM> within base station <NUM>). In an aspect, then such code and/or instructions can be used to configure and/or adapt a general purpose computer (or other device) to perform one or more operations in accordance with the described methods.

For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets, etc.), or both.

With reference to the appended figures, components that can include memory can include non-transitory machine-readable media. The term "machine-readable medium" and "computer-readable medium" as used herein, refer to any storage medium that participates in providing data that causes a machine to operate in a specific fashion. In examples provided hereinabove, various machine-readable media might be involved in providing instructions/code to processing units and/or other device(s) for execution. Additionally or alternatively, the machine-readable media might be used to store and/or carry such instructions/code. In many implementations, a computer-readable medium is a physical and/or tangible storage medium. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Common forms of computer-readable media include, for example, magnetic and/or optical media, any other physical medium with patterns of holes, a RAM, a programmable ROM (PROM), erasable PROM (EPROM), a FLASH-EPROM, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read instructions and/or code.

The methods, systems, and devices discussed herein are examples. For instance, features described with respect to certain examples may be combined in various other examples. Different aspects and elements of the examples may be combined in a similar manner. The various components of the figures provided herein can be embodied in hardware and/or software. Also, technology evolves and, thus many of the elements are examples that do not limit the scope of the disclosure to those specific examples.

It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerals, or the like. It should be understood, however, that all of these or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, as is apparent from the discussion above, it is appreciated that throughout this Specification discussion utilizing terms such as "processing," "computing," "calculating," "determining," "ascertaining," "identifying," "associating," "measuring," "performing," or the like refer to actions or processes of a specific apparatus, such as a special purpose computer or a similar special purpose electronic computing device. In the context of this Specification, therefore, a special purpose computer or a similar special purpose electronic computing device is capable of manipulating or transforming signals, typically represented as physical electronic, electrical, or magnetic quantities within memories, registers, or other information storage devices, transmission devices, or display devices of the special purpose computer or similar special purpose electronic computing device.

Terms, "and" and "or" as used herein, may include a variety of meanings that also is expected to depend, at least in part, upon the context in which such terms are used. Typically, "or" if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in the singular or may be used to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example and claimed subject matter is not limited to this example. Furthermore, the term "at least one of" if used to associate a list, such as A, B, or C, can be interpreted to mean any combination of A, B, and/or C, such as A, AB, AA, AAB, AABBCCC, etc..

Claim 1:
A method for bi-static radio-based object location detection, the method comprising:
obtaining (<NUM>, <NUM>, <NUM>), at a first wireless device, a location of a second wireless device;
obtaining (<NUM>, <NUM>, <NUM>), at the first wireless device, a time-of-flight, ToF, and an angle of arrival, AoA, of a wireless wide-area network, WWAN, reference signal transmitted (<NUM>) by a transmitting device, wherein the TOF and the AoA are obtained from measurements (<NUM>) of the WWAN reference signal at a receiving device after the WWAN reference signal is reflected by an object; and
determining (<NUM>, <NUM>, <NUM>), with the first wireless device, a location of the object from a calculation based on the location of the second wireless device, the ToF, and the AoA in combination;
wherein:
the first wireless device comprises the transmitting device and the second wireless device comprises the receiving device, or
the first wireless device comprises the receiving device and the second wireless device comprises the transmitting device.