transmission configuration of the reference radar signal and the at least one target radar signal

Abstract

In an aspect, a radar controller determines a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station, and a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal being for sensing at least one target, the first transmission configuration being different from the second transmission configuration. The radar controller transmits the first transmission configuration and the second transmission configuration to the first base station and the second base station. The first base station transmits the reference radar signal and the at least one target radar signal according to the respective transmission configurations.

Description

[0001] Cross Reference to Related Applications

[0002] This Patent Application claims the benefit of U.S. Provisional Application No. 63 / 089,314, entitled “TRANSMISSION CONFIGURATIONS FOR REFERENCE RADAR SIGNAL AND AT LEAST ONE TARGET RADAR SIGNAL,” filed October 8, 2020, and U.S. Nonprovisional Application No. 17 / 450,103, entitled “TRANSMISSION CONFIGURATIONS FOR REFERENCE RADAR SIGNAL AND AT LEAST ONE TARGET RADAR SIGNAL,” filed October 6, 2021, both of which are assigned to the assignee hereof and hereby expressly incorporated by reference herein in their entirety.

[0003] DISCLOSURE

[0004] 1. Field of the Disclosure

[0005] Aspects of the present disclosure generally relate to wireless communication, and more particularly to transmission configurations for reference radar signal and at least one target radar signal.

[0006] 2. DESCRIPTION OF THE RELATED ART

[0007] Wireless communication systems have developed through several generations, including first-generation analog wireless telephones, second-generation (2G) digital wireless telephones, third- generation (3G) high speed data wireless systems, and fourth-generation (4G) wireless communication systems. Today's wireless communication systems are quite complex and often incorporate various technologies. For example, wireless communication systems can be multiple-access systems that employ technologies for enabling communication between multiple wireless communication devices. Some wireless communication systems are cellular systems that employ cellular communication technologies. Examples of cellular systems include cellular analog systems, such as the Advanced Mobile Phone System (AMPS), and digital cellular systems, such as the digital cellular systems operating in accordance with code-division multiple access (CDMA), frequency-division multiple access (FDMA), time-division multiple access (TDMA), Global System for Mobile communication (GSM), and so on.

[0008] Fifth generation (5G) wireless standard (referred to as New Radio (NR)) calls for higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. According to the Next Generation Mobile Networks Alliance, 5G standards are designed to deliver data rates up to 10 megabits per second (Mbps), with some capabilities of 1 gigabit per second (Gbps) for mobile broadband and 50-100 Mbps for enhanced mobile broadband. Key performance indicators for 5G also include network energy savings of up to 90% and latency of 1 ms. 5G can support 1000 times more connections than current 4G and 90% energy efficiency than current 4G.

[0009] 5G enables the utilization of mmW RF signals for wireless communication between network nodes, such as base stations, user equipment (UEs), vehicles, factory automation machines, etc. However, mmW RF signals can also be utilized for other purposes. For example, mmW RF signals can be utilized for weapon systems (e.g., as short-range fire control radars in tanks and aircraft), security screening systems (e.g., in scanners that detect weapons and other dangerous items carried under clothing), medicine (e.g., to treat diseases by altering cell growth), etc.

[0010] SUMMARY

[0011] The following presents a simplified summary related to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

[0012] One aspect relates to a method of operating a radar controller, the method comprising: determining a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; determining a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmitting the first transmission configuration to the first base station and the second base station; and transmitting the second transmission configuration to the first base station and the second base station.

[0013] Another aspect relates to a method of operating a first base station, the method comprising: receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmitting the reference radar signal to the second base station on the first link according to the first transmission configuration; and transmitting the at least one target radar signal to the second base station on the at least one second link according to the second transmission configuration.

[0014] Another aspect relates to a method of operating a second base station, the method comprising: receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; receiving the reference radar signal from the first base station on the first link according to the first transmission configuration; and receiving the at least one target radar signal from the first base station on the at least one second link according to the second transmission configuration.

[0015] Another aspect relates to a radar controller, the radar controller comprising: means for determining a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; means for determining a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for transmitting the first transmission configuration to the first base station and the second base station; and means for transmitting the second transmission configuration to the first base station and the second base station.

[0016] Another aspect relates to a first base station, the first base station comprising: means for receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; means for receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for transmitting the reference radar signal to the second base station on the first link according to the first transmission configuration; and means for transmitting the at least one target radar signal to the second base station on the at least one second link according to the second transmission configuration.

[0017] Another aspect relates to a second base station, the second base station comprising: means for receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; means for receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for receiving the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and means for receiving the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0018] Another aspect relates to a radar controller, the radar controller comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver and configured to: determine a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; determine a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmit the first transmission configuration to the first base station and the second base station; and transmit the second transmission configuration to the first base station and the second base station.

[0019] Another aspect relates to a first base station, the first base station comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver and configured to: receive, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; receive, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmit the reference radar signal to the second base station on the first link in accordance with the first transmission configuration; and transmit the at least one target radar signal to the second base station on the at least one second link in accordance with the second transmission configuration.

[0020] Another aspect relates to a second base station, the second base station comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver and configured to: receive, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; receive, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; receive the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and receive the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0021] Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description. DETAILED DESCRIPTION

[0023] The accompanying drawings are included to provide a further understanding of examples of principles of the disclosure and are incorporated in and constitute a part of this specification, illustrate several examples, and, together with the description, serve to explain principles of the disclosure.

[0024] FIG. 1 An example wireless communication system is illustrated in accordance with aspects of the present disclosure.

[0025] FIG. 2A And 2B An example wireless network structure is illustrated in accordance with various aspects of the present disclosure.

[0026] FIGS. 3A-3C is a simplified block diagram of several example aspects of components that can be employed in a wireless communication node and configured to support communications as taught herein.

[0027] FIG. 4A And 4B is a diagram illustrating examples of frame structures and channels within those frame structures in accordance with aspects of the present disclosure.

[0028] FIG. 5A An example monostatic radar system is illustrated.

[0029] FIG. 5B An example bistatic radar system is illustrated.

[0030] FIG. 5C is an example plot showing a radio frequency (RF) channel response over time.

[0031] FIG. 6 An example single-target beam management use case for bistatic radio frequency sensing is illustrated.

[0032] FIG. 7 An example multi-target beam management use case for bistatic radio frequency sensing is illustrated.

[0033] FIG. 8A An example scan phase employing bistatic radio frequency sensing is illustrated.

[0034] FIG. 8B An example track phase employing bistatic radio frequency sensing is illustrated.

[0035] FIG. 9 is a simplified diagram showing the basic operation of a bistatic radar system.

[0036] FIG. 10 Implementation of a bistatic radar system in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0037] FIG. 11 is a block diagram of a wireless communication system that can include a radar controller according to an embodiment of the present disclosure.

[0038] FIG. 12 An example of a list of radar configuration parameters provided by a radar controller to a TX base station and a RX base station for a bistatic or multistatic radar measurement session according to an embodiment of the present disclosure is shown.

[0039] FIG. 13 An example of a TX / RX timing sub-list according to embodiments of the present disclosure is shown.

[0040] FIG. 14 An example of a Doppler sub-list according to embodiments of the present disclosure is shown.

[0041] FIG. 15 A cellular reference signal resource configuration for Doppler estimation according to an aspect of the present disclosure is illustrated.

[0042] FIG. 16 An interference scenario in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0043] FIG. 17 An interference scenario in a wireless communication system according to another embodiment of the present disclosure is illustrated.

[0044] FIGS. 18A-18H DL-PRS resource configuration according to aspects of the present disclosure is illustrated.

[0045] FIG. 19 PRS resource distribution according to an embodiment of the present disclosure is illustrated.

[0046] FIG. 20 PRS resource distribution according to another embodiment of the present disclosure is illustrated.

[0047] FIG. 21 An exemplary communication process in accordance with aspects of the present disclosure is illustrated.

[0048] FIG. 22 An exemplary process of wireless communication in accordance with aspects of the present disclosure is illustrated.

[0049] FIG. 23 An exemplary process of wireless communication in accordance with aspects of the present disclosure is illustrated.

[0050] FIG. 24 A communication system implementing processes in accordance with an aspect of the present disclosure is illustrated. FIGS. 21-23

[0051] DETAILED DESCRIPTION

[0052] Aspects of the present disclosure are provided in the following description and related drawings in which various examples provided for purposes of illustration and description are set forth. Alternatives to the examples described herein can be designed and can be claimed without departing from the scope of the present disclosure. Additionally, the description and drawings are not exhaustive of every possible embodiment and not necessarily indicative of all aspects of the disclosure.

[0053] The words “exemplary” and / or “example” are used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” and / or “example” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects of the disclosure” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.

[0054] Those skilled in the art will appreciate that the information and signals described below can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the description below can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular applications, design choices, and / or technologies used. These

[0055] ​Moreover, various aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence(s) of actions described herein can be considered to be embodied entirely within any form of non-transitory computer readable storage medium having stored therein

[0056] As used herein, the terms“user equipment” (UE) and“base station” (BS) are not intended to be specific to or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE can be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable device (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communications network. A UE can be mobile or can (e.g., at certain times) be stationary, and can communicate with a radio access network (RAN). As used herein, the term“UE” can be referred to interchangeably as an“access terminal” or“AT,”“client device,”“wireless device,”“subscriber device,”“subscriber terminal,”“subscriber station,”“user terminal” or UT, “mobile device,” “mobile terminal,” “mobile station,” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected to one or more external networks such as the Internet and / or to other UEs. Of course, other mechanisms of connecting to the core network and / or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE 802.11, etc.) and so on.

[0057] A base station can operate according to one of a number of RATs to communicate with UEs depending on the network in which it is deployed, and can alternatively be referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. Base stations can be used to support wireless access by UEs, including supporting data, voice, and / or signaling connections for the UEs. In some systems, the base stations can provide pure edge node signaling functionality, whereas in other systems, the base stations can provide additional control and / or network management functionality. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) can refer to either an uplink / reverse or downlink / forward traffic channel.

[0058] The term “base station” can refer to a single physical transmission-reception point (TRP) or can refer to multiple physical TRPs that can or can not be co-located. For example, where the term “base station” refers to a single physical TRP, the physical TRP can be a base station antenna corresponding to a cell (or several cell sectors) of the base station. Where the term “base station” refers to multiple co-located physical TRPs, the physical TRPs can be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming). Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs can be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via transmission medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRPs can be the serving base station from which a UE receives measurements reports and a neighbor base station whose reference RF signals (or simply “reference signals”) the UE is measuring. As used herein, a transmission from or reception at a base station refers to a particular TRP of the base station from which the base station transmits and receives wireless signals.

[0059] In some implementations that support positioning of UEs, a base station can not support wireless access by UEs (e.g., can not support data, voice, and / or signaling connections with UEs), but can instead transmit reference signals to UEs to be measured by the UEs, and / or can receive and measure signals transmitted by UEs. Such a base station can be referred to as a positioning tower (e.g., where signals are transmitted to UEs) and / or as a location measurement unit (e.g., where signals from UEs are received and measured).

[0060] An “RF signal” comprises electromagnetic waves of a given frequency that convey information over space in time between a sender and a receiver. As used herein, a sender can transmit a single “RF signal” or multiple “RF signals” to a receiver. However, due to the propagation characteristics of RF signals over multi-path channels, the receiver can receive multiple “RF signals” corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the sender and receiver can be referred to as a “multi-path” RF signal. As used herein, a RF signal can also be referred to as a “wireless signal” or simply a “signal,” where it is clear from the context that the term “signal” refers to a wireless signal or a RF signal.

[0061] Referring to FIG. 1 An example wireless communication network 100 is shown. The wireless communication system 100 (which can also be referred to as a wireless wide area network (WW AN)) can include various base stations 102 and various UEs 104. The base stations 102 can include macro cell base stations (high power cellular base stations) and / or small cell base stations (low power cellular base stations). In an aspect, the macro cell base station can include eNBs and / or ng-eNBs (where the wireless communication system 100 corresponds to an LTE network), or gNBs (where the wireless communication system 100 corresponds to a NR network), or a combination of both, and the small cell base stations can include femto cell, pico cell, micro cell, and the like.

[0062] The base stations 102 can collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or 5G core (5GC)) through backhaul links 122, and through the core network 170 to one or more location servers 172 (which can be part of core network 170 or can be external to core network 170). The base stations 102 can also perform functions such as transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 can communicate with one another directly or indirectly (e.g., through the EPC / 5GC) over backhaul links 134, which can be wired or wireless.

[0063] The base stations 102 can wirelessly communicate with the UEs 104. Each of the base stations 102 can provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more of the cells can be supported by the base station 102 in each geographic coverage area 110. A “cell” is a logical communication entity used to provide communication coverage for a particular coverage area under a carrier frequency of a base station (e.g., on a same frequency “carrier” that can be referred to as a component carrier, a frequency channel, etc.). The term “cell” can also be used to refer to a base station depending on context. A component carrier can carry one or multiple cells. A frequency band can be used to carry one or more component carriers. A “base station” as used herein refers to the set of physical and / or virtually networked devices that provide wireless access to a PLMN for one or more UEs 104 within one or more cells. “Cell” and “base station” can be used interchangeably depending on the context. In some scenarios, different cells can be configured according to different protocol types (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that can provide access for different types of UEs. Since cells are supported by a particular base station, the term “cell” can refer to a logical communication entity and / or the base station supporting such a logical communication entity, depending on context. Additionally, since a TRP is typically the physical transmission point for a cell, the terms “cell” and “TRP” can be used interchangeably. In some cases, the term “cell” can also refer to a base station’s geographic coverage area (e.g., a sector) in the sense of a carrier frequency that can be detected and used for communication within some portion of the geographic coverage area 110.

[0064] Although the geographic coverage area 110 for each adjacent macro cell base station 102 can overlap in such a way to create an inter-femto cell coverage area 112, the geographic coverage area 110 of some macro cell base stations 102 can not overlap with that of the other macro cell base stations 102. FIG. 1 depicts the inter-femto cell coverage area 112 as a completely overlapped area, but it should be appreciated that the inter-femto cell coverage area 112 can not be completely overlapped, and each femto cell base station 102 can have an associated coverage area 110 that is partially overlapped with the coverage areas 110 of other femto cell base stations 102.

[0065] The communication links 120 between the base stations 102 and the UEs 104 can include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and / or downlink (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 can use MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links 120 can be through one or more carrier frequencies. Allocation of carriers can be asymmetric with respect to downlink and uplink (e.g., more or less carriers can be allocated for downlink than for uplink).

[0066] Wireless communications system 100 can further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and / or the WLAN AP 150 can perform a clear channel assessment (CCA) or listen before talk (LBT) procedure to determine whether the channel is available prior to communicating.

[0067] The small cell base stations 102' can operate in a licensed or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base stations 102' can employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base stations 102' employing LTE / 5G in an unlicensed frequency spectrum can boost coverage and / or increase capacity for the access network. NR in an unlicensed frequency spectrum can be referred to as NR-U. LTE in an unlicensed frequency spectrum can be referred to as LTE-U, License Assisted Access (LAA), or MulteFire.

[0068] The wireless communications system 100 can further include a millimeter wave (mmW) base station 180 that can operate in mmW frequencies and / or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range from 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band can be referred to as a millimeter wave. Near mmW can extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW / near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmit and / or receive) over the mmW communication link 184 to compensate for the extremely high path loss and short range. Further, it will be appreciated that, in alternative configurations, one or more base stations 102 can also transmit using mmW or near mmW and beamforming. Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed as being limiting of the various aspects disclosed herein.

[0069] Transmit beamforming is a technique for focusing the RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts a RF signal, it broadcasts the signal in all directions (omni-directionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device(s). To change the direction of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, the network node can use an array of antennas (known as a “phased array” or “antenna array”) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while cancelling to suppress radiation in undesired directions.

[0070] The transmit beams can be quasi-collocated, meaning that they appear to have the same parameters at the receiver (e.g., UE), regardless of whether the network node’s transmit antennas themselves are physically co-located. In NR, there are four types of quasi-collocation (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. As such, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.

[0071] In receive beamforming, the receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an antenna array in a particular direction to amplify an RF signal received from that direction (e.g., increase its gain level). Thus, when a receiver is said to beamform in a certain direction, this means that the beam gain in that direction is higher relative to the beam gain in other directions, or that the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal to interference plus noise ratio (SINR), etc.) for RF signals received from that direction.

[0072] The receive beam can be spatially related. Spatially related means that parameters of a transmit beam for a second reference signal can be derived from information about a receive beam for a first reference signal. For example, a UE can use a particular receive beam to receive one or more reference downlink reference signals (e.g., positioning reference signals (PRSs), tracking reference signals (TRSs), phase tracking reference signals (PTRSs), cell-specific reference signals (CRSs), channel state information reference signals (CSI-RSs), primary synchronization signals (PSSs), secondary synchronization signals (SSSs), synchronization signal blocks (SSBs), etc.) from a base station. The UE can then form a transmit beam based on parameters of the receive beam for transmitting one or more uplink reference signals (e.g., uplink positioning reference signals (UL-PRSs), sounding reference signals (SRSs), demodulation reference signals (DMRSs), PTRSs, etc.) to the base station.

[0073] Note that depending on the entity forming the “downlink” beam, the beam can be a transmit beam or a receive beam. For example, if the base station is forming the downlink beam to transmit a reference signal to the UE, the downlink beam is a transmit beam. However, if the UE is forming the downlink beam, the downlink beam is a receive beam for receiving a downlink reference signal. Similarly, depending on the entity forming the “uplink” beam, the beam can be a transmit beam or a receive beam. For example, if the base station is forming the uplink beam, the uplink beam is an uplink receive beam, while if the UE is forming the uplink beam, the uplink beam is an uplink transmit beam.

[0074] In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is partitioned into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and in the cell in which the UE 104 / 182 performs an initial radio resource control (RRC) connection establishment procedure or initiates a RRC connection reestablishment procedure. The primary carrier carries all common control channels as well as UE-specific control channels, and can be a carrier in a licensed frequency (although this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that can be configured once the RRC connection is established between the UE 104 and the anchor carrier, and which can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier in an unlicensed frequency. The secondary carrier can contain only necessary signaling information and signals, e.g., UE-specific signaling information and signals can not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104 / 182 in a cell can have different downlink primary carriers. The same is true for the uplink primary carrier. The network is able to change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers. Since a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier that a certain base station is currently using for communication, the terms “cell,” “serving cell,” “component carrier,” “carrier frequency,” and the like can be used interchangeably.

[0075] For example, still referring to FIG. 1 One of the frequencies utilized by a macrocell base station 102 can be an anchor carrier (or “PCell”), and other frequencies utilized by that macrocell base station 102 and / or mmW base station 180 can be secondary carriers (“SCells”). Simultaneous transmission and / or reception on multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rate. For example, two 20 MHz aggregated carriers in a multi-carrier system compared to the data rate obtained by a single 20 MHz carrier would theoretically result in a doubling of the data rate (i.e., 40 MHz).

[0076] The wireless communications system 100 can further include a UE 164 that can be in communication with the macro cell base station 102 over the communication link 120 and / or in communication with the mmW base station 180 over the mmW communication link 184. For example, the macro cell base station 102 can support a PCell and one or more SCells for the UE 164, and the mmW base station 180 can support one or more SCells for the UE 164.

[0077] The wireless communications system 100 can further include one or more UEs, such as UE 190, that can indirectly connect to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “sidelinks”). For example, UEs 104 can indirectly connect to the cellular network via D2D P2P links 192 with UEs 104 connected to the base stations 102, and UEs 104 can FIG. 1 In an example, the UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (by which the UE 190 can thereby indirectly obtain cellular connectivity), and a D2D P2P link 194 with the WLAN STA 152 connected to the WLAN AP 150 (by which the UE 190 can thereby indirectly obtain WLAN-based Internet connectivity). In one example, the D2D P2P links 192 and 194 can be supported with any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

[0078] Referring to FIG. 2A An example wireless network architecture 200 is shown. For example, a 5GC 210 (also referred to as Next Generation Core (NGC)) can be viewed functionally as control plane functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane functions 212 (e.g., UE gateway function, access to data networks, IP FIG. 1 ​The UE 204 can communicate with any UE depicted herein. Another optional aspect may include a location server 230, which may communicate with the 5GC 210 to provide location assistance to the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204, which can connect to the location server 230 via the core network, the 5GC 210, and / or via the Internet (not described). Furthermore, the location server 230 may be integrated into a component of the core network, or alternatively, may be external to the core network.

[0079] Reference FIG. 2B Another example wireless network architecture 250 is shown. For example, 5GC 260 can be functionally considered as a control plane function (provided by Access and Mobility Management Function (AMF) 264) and a user plane function (provided by User Plane Function (UPF) 262), which operate cooperatively to form the core network (i.e., 5GC 260). User plane interface 263 and control plane interface 265 connect ng-eNB 224 to 5GC 260, specifically to UPF 262 and AMF 264, respectively. In an additional configuration, gNB 222 can also connect to 5GC 260 via control plane interface 265 to AMF 264 and user plane interface 263 to UPF 262. Furthermore, ng-eNB 224 can communicate directly with gNB 222 via backhaul connection 223, with or without gNB direct connectivity to 5GC 260. In some configurations, the new RAN 220 may have only one or more gNB 222s, while other configurations include both one or more ng-eNB 224s and one or more gNB 222s. The gNB 222 or ng-eNB 224 can be used with UE 204 (e.g., FIG. 1 The base station of the new RAN 220 communicates with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface.

[0080] The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful intercept, transport for session management (SM) messages between the UE 204 and a session management function (SMF) 266, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE 204 and an SMS function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204, and receives a medium key as a result of the UE 204 authentication process. In cases where a universal mobile telecommunications system (UMTS) subscriber identity module (SIM) is used for authentication, the AMF 264 retrieves the security material from the AUSF. The functions of the AMF 264 also include security context management (SCM). The SCM receives a key from the SEAF that it uses to derive access network- specific keys. The functionality of the AMF 264 also includes location management for regulatory services, transport for location service messages between the UE 204 and a location management function (LMF) 270, which acts as a location server 230, transport for location service messages between the new RAN 220 and the LMF 270, evolved packet system (EPS) bearer identifier allocation for interworking with the EPS, and UE 204 mobility event notification. In addition, the AMF 264 also supports functionality for non-3GPP access networks.

[0081] The functions of the UPF 262 include acting as an anchor point for intra- / inter-RAT mobility (when applicable), acting as a external protocol data unit (PDU) session point of interconnect to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful intercept (user plane collection), traffic usage reporting, quality of service (QoS) handling for user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding of one or more “end markers.” The UPF 262 can also support transport for location service messages between the UE 204 and a location server, such as a secure user plane location (SUPL) location platform (SLP) 272, over a user plane.

[0082] The functions of SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, traffic bootstrapping configuration at UPF 262 for routing traffic to the correct destination, partial control of policy enforcement and QoS, and downlink data notification. The interface used by SMF 266 to communicate with AMF 264 is called the N11 interface.

[0083] Another optional aspect may include LMF 270, which can communicate with 5GC 260 to provide location assistance to UE 204. LMF 270 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. LMF 270 may be configured to support one or more location services for UE 204, which can connect to LMF 270 via the core network, 5GC 260, and / or via the Internet (not explained). SLP 272 supports similar functionality to LMF 270, but while LMF 270 can communicate with AMF 264, the new RAN 220, and UE 204 on the control plane (e.g., using interfaces and protocols designed to convey signaling messages rather than voice or data), SLP 272 can communicate with UE 204 and external clients on the user plane (e.g., using protocols designed to carry voice and / or data, such as Transmission Control Protocol (TCP) and / or IP). FIG. 2B (Not shown in the image) communicates.

[0084] On one hand, the LMF 270 and / or SLP 272 can be integrated into base stations (such as gNB 222 and / or ng-eNB 224). When integrated into gNB 222 and / or ng-eNB 224, the LMF 270 and / or SLP 272 may be referred to as a “location management component” or “LMC”. However, as used herein, references to LMF 270 and SLP 272 include both cases where LMF 270 and SLP 272 are components of the core network (e.g., 5GC 260) and cases where LMF 270 and SLP 272 are components of the base station.

[0085] Referenced FIG. 3A , 3BAnd 3C, show that can be incorporated into UE 302 (which can correspond to any UE described herein), base station 304 (which can correspond to any base station described herein), and network entity 306 (which can correspond to or embody any network function described herein, including location server 230 and LMF 270) to support file transfer operations of several example components (represented by corresponding blocks). It will be appreciated that these components can be implemented in different types of apparatuses in different implementations (e.g., in ASICs, in system-on-chips (SoCs), etc.). The illustrated components can also be incorporated into other apparatuses in a communication system. For example, other apparatuses in the system can include similar components to those described to provide similar functionality. Moreover, a given apparatus can contain one or more of these components. For example, an apparatus can include multiple transceiver components that enable the apparatus to operate on multiple carriers and / or communicate via different technologies.

[0086] UE 302 and base station 304 each include wireless wide area network (WW AN) transceivers 310 and 350, respectively, configured for communication via one or more wireless communication networks (not shown), such as NR networks, LTE networks, GSM networks, and / or the like. WWAN transceivers 310 and 350 can connect to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), and / or the like, via one or more designated RATs (e.g., NR, LTE, GSM, and / or the like) over a wireless communication medium (e.g., a set of time / frequency resources in a particular frequency spectrum) of interest. WWAN transceivers 310 and 350 can be variously configured for transmitting and encoding signals 318 and 358 (e.g., messages, indications, information, and / or the like), respectively, and, conversely, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, and / or the like), respectively, in accordance with the designated RATs. Specifically, transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, respectively, and one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358, respectively.

[0087] At least in some scenarios, UE 302 and base station 304 also include wireless local area network (WLAN) transceivers 320 and 360, respectively. WLAN transceivers 320 and 360 can connect to one or more antennas 326 and 366, respectively, for communicating using at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth®, and / or the like) via one or more local area or personal area networks, such as networks based on IEEE 802.16, IEEE 802.11, IEEE 802.15, IEEE 802.3, and / or the like. The WLAN transceivers 320 and 360 can be variously configured to respectively transmit and encode signals 328 and 368 (e.g., messages, indications, information, and so on) and to respectively receive and decode signals 328 and 368 (e.g., messages, indications, information, pilots, and so on) in accordance with specified RATs, in various ways. Specifically, the transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, to respectively transmit and encode signals 328 and 368, and one or more receivers 322 and 362, respectively, to respectively receive and decode signals 328 and 368.

[0088] Transceiver circuitry including at least one transmitter and at least one receiver can comprise integrated devices (e.g., implemented as transmitter and receiver circuits of a single communication device) in some implementations, separate transmitter and receiver devices in some implementations, or can be otherwise implemented, in other implementations. In an aspect, a transmitter can include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which permits it to perform transmit “beamforming,” as described herein. Similarly, a receiver can include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which permits it to perform receive beamforming, as described herein. In an aspect, a transmitter and a receiver can share the same multiple antennas (e.g., antennas 316, 326, 356, 366), such that the respective apparatus can either receive or transmit at a given time, but not both. The wireless communication device(s) of the UE 302 and / or the base station 304 (e.g., one or both of the transceivers 310 and 320 and / or one or both of the transceivers 350 and 360) can also include a network listening module (NLM) or the like for performing various measurements.

[0089] At least in some cases, the UE 302 and the base station 304 also include satellite positioning system (SPS) receivers 330 and 370. The SPS receivers 330 and 370 can be connected to one or more antennas 336 and 376, respectively, for receiving SPS signals 338 and 378 (such as global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), and / or the like), respectively. The SPS receivers 330 and 370 can include any suitable hardware and / or software for receiving and processing SPS signals 338 and 378, respectively. The SPS receivers 330 and 370 request information and operations from other systems as appropriate, and perform the necessary calculations to determine the position of the UE 302 and the base station 304 using measurements obtained by any suitable SPS algorithm.

[0090] The base station 304 and the network entity 306 each include at least one network interface 380 and 390 for communicating with other network entities. For example, the network interfaces 380 and 390 (e.g., one or more network access ports) can be configured to communicate with one or more network entities via a wire-based backhaul connection or a wireless backhaul connection. In some aspects, the network interfaces 380 and 390 can be implemented as transceivers configured to support wire-based or wireless signal communication. This communication can involve, for example, sending and receiving: messages, parameters, and / or other types of information.

[0091] The UE 302, the base station 304, and the network entity 306 also include other components that can be beneficial to utilize in connection with the operations as disclosed herein. The UE 302 includes processor circuitry that implements a processing system 332 for providing functionality relating to, for example, RF sensing, and for providing other processing functionality. The base station 304 includes a processing system 384 for providing functionality relating to, for example, RF sensing as disclosed herein, and for providing other processing functionality. The network entity 306 includes a processing system 394 for providing functionality relating to, for example, RF sensing as disclosed herein, and for providing other processing functionality. In an aspect, the processing systems 332, 384, and 394 can include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGA), or other programmable logic devices or processing circuitry.

[0092] The UE 302, the base station 304, and the network entity 306 include memory circuitry implementing memory components 340, 386, and 396, respectively (e.g., each including a memory device), for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and the like). In some cases, the UE 302, the base station 304, and the network entity 306 can include radar components 342, 388, and 398, respectively. The radar components 342, 388, and 398 can be hardware circuitries that are part of, or coupled to, the processing systems 332, 384, and 394, respectively, that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. In other aspects, the radar components 342, 388, and 398 can be external to the processing systems 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, and / or the like). Alternatively, the radar components 342, 388, and 398 can be memory modules stored in the memory components 340, 386, and 396, respectively, as illustrated in FIG. 3B, that, when executed by the processing systems 332, 384, and 394 (or a modem processing system, another processing system, and / or the like) cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. FIGS. 3A-3C

[0093] The UE 302 can include one or more sensors 344 coupled to the processing system 332 to provide movement and / or orientation information independent of motion data derived from signals received by the WWAN transceiver 310, the WLAN transceiver 320, and / or the SPS receiver 330. As examples, the sensor(s) 344 can include an accelerometer (e.g., a micro-electrical-mechanical system (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of movement detection sensor. Moreover, the sensor(s) 344 can include multiple different types of devices and combine their outputs to provide motion information. For example, the sensor(s) 344 can use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute a position in 2D and / or 3D coordinate systems.

[0094] Additionally, the UE 302 includes a user interface 346 for providing indications (e.g., audible and / or visual indications) to a user and / or for receiving user input (e.g., upon user actuation of a sensing device such as a keypad, a touch screen, a microphone, etc.). Although not shown, the base station 304 and the network entity 306 can also include user interfaces.

[0095] ​Referring to the processing system 384 in more detail, in the downlink, IP packets from the network entity 306 can be provided to the processing system 384. The processing system 384 can implement functionality for the RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The processing system 384 can provide RRC layer functionality associated with system information (e.g., master information block (MIB), system information blocks (SIBs)) acquisition, RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error detection at the protocol interface, error correction through automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC data PDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0096] The transmitter 354 and the receiver 352 can implement layer-1 functionality associated with various signal processing functions. Layer-1, which includes a physical (PHY) layer, can include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping to physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The transmitter 354 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to a orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator can be used to determine the coding and modulation schemes, as well as for spatial processing. The channel estimate can be

[0097] At the UE 302, the receiver 312 receives a signal through its respective antenna(s) 316. The receiver 312 recovers information modulated onto an RF carrier and provides the information to the processing system 332. The transmitter 314 and the receiver 312 implement Layer- 1 functionality associated with various signal processing functions. The receiver 312 can perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they can be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 304. These soft decisions can be based on channel estimates computed by the channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 304 on the physical channel. The data and control signals are then provided to the processing system 332, which implements Layer-3 and Layer-2 functionality.

[0098] On the uplink, the processing system 332 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The processing system 332 is also responsible for error detection.

[0099] Similar to the functionality described in connection with the downlink transmission by the base station 304, the processing system 332 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0100] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 can be used by the transmitter 314 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter 314 can be provided to different antenna(s) 316. The transmitter 314 can modulate an RF carrier with a respective spatial stream for transmission.

[0101] The uplink transmission is processed at the base station 304 in a manner similar to that described in connection with the receiver function at the UE 302. A receiver 352 receives the signal through its respective antenna(s) 356. The receiver 352 recovers the information modulated onto the RF carrier and provides the information to the processing system 384.

[0102] In the uplink, the processing system 384 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 302. IP packets from the processing system 384 can be provided to the core network. The processing system 384 is also responsible for error detection.

[0103] For convenience, the UE 302, base station 304, and / or network entity 306 are shown FIGS. 3A-3C as including various components configured to configure according to the various examples described herein. It will be appreciated, however, that the illustrated blocks can have different functionality in different designs.

[0104] The various components of the UE 302, base station 304, and network entity 306 can respectively communicate with one another over data buses 334, 382, and 392. FIGS. 3A-3C The components of the various examples can be implemented in a wide variety of ways. In some implementations, FIGS. 3A-3CThe components of the UE 302 and the base station 304 can be implemented in one or more circuits (e.g., one or more processors and / or one or more ASICs (which can include one or more processors)), which can include at least one memory component. Here, each circuit can use and / or incorporate at least one memory component for storing information or executable code used by that circuit to provide the functionality described herein. For example, some or all of the functionality represented by blocks 310 to 346 can be implemented by a processor and memory component(s) of the UE 302 (e.g., by executing appropriate code and / or by appropriately configuring a processor component). Similarly, some or all of the functionality represented by blocks 350 to 388 can be implemented by a processor and memory component(s) of the base station 304 (e.g., by executing appropriate code and / or by appropriately configuring a processor component). Further, some or all of the functionality represented by blocks 390 to 398 can be implemented by a processor and memory component(s) of the network entity 306 (e.g., by executing appropriate code and / or by appropriately configuring a processor component). For simplicity, various operations, acts, and / or functions are described herein as being performed by a UE, a base station, a positioning entity, and / or the like. However, as will be appreciated, such operations, acts, and / or functions can actually be performed by specific components or combinations of components of the UE, base station, positioning entity, and / or the like, such as the processing systems 332, 384, 394, transceivers 310, 320, 350, and 360, memory components 340, 386, and 396, radar components 342, 388, and 398, and / or the like.

[0105] FIG. 4A FIG. 400 is a diagram 400 illustrating an example of a DL frame structure, in accordance with aspects of the present disclosure. FIG. 4B FIG. 430 is a diagram 430 illustrating an example of channels within a DL frame structure, in accordance with aspects of the present disclosure. Other wireless communication technologies can have a different frame structure and / or different channels.

[0106] LTE and in some cases NR utilize OFDM on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. Different from LTE, however, NR also has an option of using OFDM on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, subcarriers, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing of the adjacent subcarriers can be fixed, and the total number of subcarriers (K) can be dependent on the system bandwidth. For example, the spacing of the subcarriers can be 15 kHz and the minimum resource allocation (called a “resource block” (RB)) can be 12 subcarriers (or 180 kHz). Consequently, for a 1.25, 2.5, 5, 10, or 20 megahertz (MHz) system bandwidth, the nominal FFT size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be partitioned into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and there can be 1, 2, 4, 8, or 16 subbands for a 1.25, 2.5, 5, 10, or 20 MHz system bandwidth, respectively.

[0107] LTE supports a single numerology (subcarrier spacing, symbol length, etc.). In contrast, NR can support multiple numerologies, e.g., subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 204 kHz or larger can be available. Table 1 provided below lists some various parameters for different NR numerologies.

[0108]

[0109] Table 1

[0110] In the example of FIG. 4A and 4B , a numerology of 15 kHz is used. Thus, in the time domain, a frame (e.g., 10 ms) is divided into 10 equal sized subframes, each subframe of 1 ms, with each subframe comprising one slot. In the example of FIG. 4A and 4B , time is represented horizontally (e.g., along the x-axis) with increasing time from left to right, and frequency is represented vertically (e.g., along the y-axis) with increasing (or decreasing) frequency from bottom to top.

[0111] A resource grid can be used to represent time slots, each time slot including one or more time-concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE can correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In FIG. 4A and 4B In the parameter design of

[0112] As illustrated in FIG. 4A , some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. The DL-RS can include demodulation reference signals (DMRS) and channel state information reference signals (CSI-RS), exemplary locations of which are labeled “R” in FIG. 4A

[0113] FIG. 4B Examples of various channels within the DL subframe of a frame are illustrated. The physical downlink control channel (PDCCH) carries DL control information (DCI) within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. The DCI carries information about UL resource allocation (persistent and non- persistent) and descriptions about DL data transmitted to the UE. Multiple (e.g., up to eight) DCIs can be configured in the PDCCH, and the DCIs can have one of multiple formats. For example, there are different DCI formats for UL scheduling, for non-MIMO DL scheduling, for MIMO DL scheduling, and for UL power control.

[0114] ​A primary synchronization signal (PSS) is used by a UE to determine subframe / symbol timing and a physical layer identity. A secondary synchronization signal (SSS) is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the PCI. Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH), which carries an MIB, can be logically grouped with the PSS and SSS to form an SSB (also referred to as an SS / PBCH). The MIB provides a number of RBs in the DL system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information such as system information blocks (SIBs), and paging messages. FIG. 4A The DL RSs illustrated in FIG. 13 can be positioning reference signals (PRSs).

[0115] Wireless communication signals (e.g., RF signals configured to carry OFDM symbols) transmitted between UEs and base stations can be repurposed for environmental sensing (also referred to as “RF sensing” or “radar”). Environmental sensing using wireless communication signals can be viewed as a consumer-grade radar with advanced detection capabilities that, among other things, is capable of touchless / device-free interaction with devices / systems. The wireless communication signals can be cellular communication signals, such as LTE or NR signals, WLAN signals, etc. As a particular example, the wireless communication signals can be OFDM waveforms used in LTE and NR. Higher frequency communication signals, such as mmW RF signals, are particularly advantageous for use as radar signals because the higher frequencies provide, at a minimum, more accurate range (distance) detection.

[0116] Generally, there are different types of radars, in particular, monostatic and bistatic radars. FIG. 5A and 5B Two of these different types of radars are illustrated. In particular, FIG. 5A is a diagram 500 illustrating a monostatic radar scenario, and FIG. 5B is a diagram 530 illustrating a bistatic radar scenario. In FIG. 5A , the base station 502 can be configured for full duplex operation, and as such the transmitter (Tx) and receiver (Rx) are co-located. For example, the transmitted radio signals 506 can be reflected by a target object, such as a building 504, and the receiver on the base station 502 is configured to receive and measure the reflected beam 508. This is a typical use case for a conventional or regular radar. In FIG. 5BIn this example, the base station 505 can be configured as a transmitter (Tx) and the UE 532 can be configured as a receiver (Rx). In this example, the transmitter and receiver are not co-located, i.e., they are separate. The base station 505 can be configured to transmit a beam, such as an omnidirectional downlink RF signal 506 that can be received by the UE 532. A portion of the RF signal 506 can be reflected or refracted by the building 504, and the UE 532 can receive a reflected signal 534. This is a typical use case for RF sensing based on wireless communication (e.g., WiFi based, LTE based, NR based). Note that, while FIG. 5B While the downlink RF signal 506 is illustrated as being used as the RF sensing signal, an uplink RF signal can also be used as the RF sensing signal. In a downlink scenario, as illustrated, the transmitter is the base station 505 and the receiver is the UE 532, while in an uplink scenario, the transmitter is the UE and the receiver is the base station.

[0117] Referring to the example of FIG. 5 in more detail FIG. 5B The base station 505 transmits an RF sensing signal (e.g., a PRS) to the UE 532, but some of the RF sensing signal is reflected from a target object, such as the building 504. The UE 504 can measure the ToA of the RF signal 506 received directly from the base station, as well as the ToA of the reflected signal 534 reflected from the target object (e.g., the building 504).

[0118] The base station 505 can be configured to transmit a single RF signal 506 or multiple RF signals to the receiver (e.g., the UE 532). However, due to the propagation characteristics of the RF signal through a multipath channel, the UE 532 can receive multiple RF signals corresponding to each transmitted RF signal. Each path can be associated with a cluster of one or more channel taps. Generally, the time at which the receiver detects a first cluster of channel taps is considered the ToA of the RF signal on a line-of-sight (LOS) path (i.e., the shortest path between the transmitter and the receiver). Later clusters of channel taps are considered to have reflected off of an object between the transmitter and the receiver, and thus have followed a non-LOS (NLOS) path between the transmitter and the receiver.

[0119] Referring back to FIG. 5B The RF signal 506 follows a LOS path between the base station 505 and the UE 532, and the reflected signal 534 represents an RF sensing signal that follows a NLOS path between the base station 505 and the UE 532 due to reflection from the building 504 (or another target object). The base station 505 can have transmitted multiple RF sensing signals FIG. 5BSome of the plurality of RF sensing signals follow a LOS path, and others of the plurality of RF sensing signals follow a NLOS path. Alternatively, the base station 505 can have transmitted a single RF sensing signal in a beam that is wide enough, where portions of the RF sensing signal follow a LOS path and portions of the RF sensing signal follow a NLOS path.

[0120] Based on the ToA of the LOS path, the ToA of the NLOS path, and the speed of light, the UE 532 can determine the distance to the building 504. Additionally, if the UE 532 is able to receive beamforming, the UE 532 can be able to determine the general direction to the building 504 as the direction of the reflected signal 534, which is the RF sensing signal following the NLOS path as received. The UE 532 can then optionally report this information to the transmitting base station 505, an application server associated with a core network, an external client, a third-party application, or some other entity. Alternatively, the UE 532 can report the ToA measurements to the base station 505, or other entity, and the base station 505 can determine the distance to the target object and optionally the direction to the target object.

[0121] Note that if the RF sensing signal is an uplink RF signal transmitted by the UE 532 to the base station 505, the base station 505 will perform object detection based on the uplink RF signal, just as the UE 532 performs object detection based on the downlink RF signal.

[0122] Referring to FIG. 5C , an example plot 550 is shown that illustrates the RF channel response at a receiver (e.g., any of the UEs or base stations described herein) over time. In the example of FIG. 5C , the receiver receives multiple (four) clusters of channel taps. Each channel tap represents a multipath that the RF signal followed between a transmitter (e.g., any of the UEs or base stations described herein) and the receiver. That is, a channel tap represents an arrival of the RF signal on a multipath. Each cluster of channel taps indicates that the corresponding multipaths followed substantially the same path. There can be different clusters due to the RF signal being transmitted on different transmit beams (and thus at different angles), or due to the propagation characteristics of the RF signal (e.g., due to reflections potentially following widely different paths), or both.

[0123] In FIG. 5CUnder the channel illustrated in the explanation, the receiver receives a first cluster of two RF signals on the channel taps at time T1, a second cluster of five RF signals on the channel taps at time T2, a third cluster of five RF signals on the channel taps at time T3, and a fourth cluster of four RF signals on the channel taps at time T4. In FIG. 5C the example, since the first RF signal cluster arrives first at time T1, it is assumed to be the LOS data stream (i.e., the data stream that arrives on the LOS or shortest path), and can correspond to FIG. 5B the LOS path (e.g., RF signal 506) illustrated in the explanation. The third cluster at time T3 is composed of the strongest RF signals, and can correspond to FIG. 5B the NLOS paths (e.g., reflected signals 534) illustrated in the explanation. Note that, although FIG. 5C two to five clusters of channel taps are illustrated, as will be appreciated, the clusters can have more or less channel taps than illustrated.

[0124] Referring to FIG. 6 , an example single-target beam management use case 600 for bistatic radio frequency sensing is shown. The use case 600 includes a base station 602 (such as a 5G NR gNB) configured to transmit multiple beamformed signals along different azimuth and / or elevation, and a UE 610 configured to utilize receive beamforming to improve signal gain based on angle of arrival. The base station 602 can be configured to generate N different reference beams and various azimuth, elevation, and / or beam widths. In an example, the beams transmitted by the base station 602 can be based on SS blocks, CSI-RS, TRS, or PRS resource sets. Other sensing and tracking reference signals can also be used. The UE 610 can be configured to utilize phase shifters and other software and hardware techniques to generate receive beams, such as a first receive beam 612, a second receive beam 614, and a third receive beam 616. The UE 610 can also be configured to beamform for transmitted beams. The base station 602 can transmit a first reference signal 604 in the direction of a target object, such as a building 504, which can be reflected, and the UE 610 can receive the reflected signal 606 using the first receive beam 612. The reflected signal 606 represents an NLOS path of the first reference signal 604 to the UE 610. The base station 602 also transmits a second reference signal 608 on a second beam. In an example, the second reference signal 608 can be quasi-collocated (QCLed) with the first reference signal 604. The UE 610 receives the second reference signal 608 using the second receive beam 614. The second reference signal 608 is an LOS path to the UE 610.

[0125] In operation, the UE 610 can be configured to report a channel response for each of the first and second reference signals 604, 608 to the base station 602 or another serving cell, and the base station 602 can be configured to manage transmit and receive beam pairs for object sensing. For example, the base station 602 can be configured to provide transmit and receive beam identification information to the UE 610 to track an object, such as the building 504. The beam identification information can be a transmission configuration indicator (TCI) sent in a DCI message that includes configurations such as QCL relationships between transmit and receive beams.

[0126] Referring now FIG. 7 , with further reference to FIG. 6 , an example multi-target use case 700 for bistatic radio frequency sensing is shown. The use case 700 extends the single-target use case 600 by including a second target FIG. 6 . By way of example, but not limitation, the second target can be a second building 704. The number and nature of targets can vary based on the environment and radio sensing application. In the use case 700, the base station 602 transmits a third reference signal 702 that is reflected by the second building 704, and the resulting reflected signal 708 is detected by a second receive beam 614 of the UE 610. The UE 610 can report a channel response for the third reference signal 702 with an indication that the measurement was obtained using the second receive beam 614. The base station 602 is configured to manage a beam pair associated with the second target (i.e., the third reference signal 702 and the second receive beam 614). Additional targets and corresponding beam pairs can also be managed by the base station 602. The base station 602 can be configured to track one or more targets, and from this can provide corresponding beam pair information to the UE 610 as QCL / TCI for the respective targets.

[0127] Referring now FIG. 8A, an example scan phase 800 with bistatic radio frequency sensing is shown. The base station 802 is an example of the base station 304 and is configured to transmit multiple beamformed reference signals with varying azimuth, elevation, and / or beamwidth. The reference signals can be SS blocks, CSI-RS, TRS, PRS, or a sensing scan reference signal (SSRS) configured for RF sensing applications. The UE 810 is an example of the UE 302 and can be configured to perform receive beam sweeping along different azimuth, elevation, and / or beamwidths relative to the orientation of the UE 810. In operation, the base station 802 can transmit one or more of the reference signals in a sequential order (i.e., beam sweeping), and the UE 810 is configured to beam sweep through different receive beams. The scan phase 800 can be used to initially detect potential objects to be tracked via RF sensing. For example, the first reference signal 804 can be reflected by the first object 820a, and the first reflected reference signal 804a can be detected by the UE 810. The UE 810 can cycle through different receive beams, such as the first receive beam 812, the second receive beam 814, and the third receive beam 816. As depicted in FIG. 8A , the first reflected reference signal 804a can be received using the first receive beam 812. The UE 810 can also detect the second reference signal 805 via a LOS path using the second receive beam 814. The beam sweep on the base station 802 can generate the third reference signal 806, which is reflected on the second object 820b, and the third reflected reference signal 806a is received by the UE 810 on the third receive beam 816.

[0128] In an embodiment, the UE 810 can be configured to detect targets based on the RSRP of the received signals. For example, the UE 810 can report that the RSRP values associated with the first reference signal 804 and the third reference signal 806 are above a threshold. The threshold can be a fixed value, or can be scaled based on the RSRP of the LOS signal, such as the second reference signal 805. The UE 810 is configured to report one or more channel measurements (e.g., RSRP, RSRQ, SINR) associated with the received reference signals to the base station 802 or other network node. The measurements obtained during the scan phase 800 can be used for subsequent tracking phases.

[0129] Referring to FIG. 8B , further referring to FIG. 8A , an example tracking phase 850 with bistatic radio frequency sensing is shown. Continuing from the scan phase 800, the base station 802 transmits the first reference signal 804 and the third reference signal 806. The UE 810 is configured to track the first object 820a and the second object 820b using the first receive beam 812 and the third receive beam 816, respectively. The UE 810 can also track the second object 820b using the second receive beam 814. The UE 810 can be configured to track the objects based on the RSRP of the received signals. For example, the UE 810 can track the first object 820a and the second object 820b based on the RSRP of the first reference signal 804 and the third reference signal 806, respectively. The UE 810 can also track the second object 820b based on the RSRP of the second reference signal 805. The UE 810 can be configured to track the objects based on the RSRP of the received signals. For example, the UE 810 can track the first object 820a and the second object 820b based on the RSRP of the first reference signal 804 and the third reference signal 806, respectively. The UE 810 can also track the second object 820b based on the RSRP of the second reference signal 805. FIG. 8AFor the example, the base station 802 (or another network node in the communication system 100) can determine to track one or more objects detected in the scanning phase 800. For example, the base station 802 can select to track the first object 820a and will transmit beam configuration information to the UE 810 to enable the UE 810 to track the first object 820a. The beam configuration information can include reference signal information and receive beam configuration information for the UE 810. The base station 802 can track or refine measurements associated with the first object with a sensing tracking reference signal (STRS) based on the first reference signal 804. In an example, the STRS can be quasi-co-located with the corresponding SSRS (i.e., the first reference signal 804). SS blocks, CSI-RS, TRS, and PRS can be used as STRS. Other reference signals can also be developed and used as STRS. The beam configuration information transmitted to the UE 810 can be transmitted via RRC, medium access control control element (MAC-CE), DCI, or other signaling protocols. Upon receiving the beam configuration information, the UE 810 can detect the first object 820a, for example, using the first receive beam 812 with the STRS.

[0130] The base station 802 can be configured to track multiple targets based on the number of reference signals that the base station 802 can generate. In an embodiment, the base station 802 can be configured to track one object per reference signal. For example, the base station 802 can track the second object 820b by generating a second STRS based on the third reference signal 806. The beam configuration information transmitted to the UE 810 can include beam parameters for the second STRS and corresponding receive beam information (e.g., the third receive beam 816) provided by the UE 810 during the scanning phase 800. As such, the UE 810 can be configured to track both the first object 820a and the second object 820b. Up to as many additional objects can be tracked as the number of reference signals generated by the base station 802.

[0131] FIG. 9 is a simplified diagram illustrating the basic operation of a bistatic radar system 900. A transmitter 902 and a receiver 904 are used to transmit and receive radar signals to sense a target 906. While a bistatic radar example is shown, the same operational principles can be applied to multistatic radar that utilizes more than two transmitters / receivers. For example, a multistatic radar can utilize one transmitter and two receivers. In another example, a multistatic radar can utilize two transmitters and one receiver. Larger numbers of transmitters and / or receivers are also possible.

[0132] In the bistatic radar system 900, the transmitter 902 transmits a transmit signal 908 that passes through a distance R TThe transmitted signal 908 is reflected from target 906 and becomes echo signal 910. Echo signal 910 travels across the range RR to reach receiver 904. The primary function of the bistatic radar system 900 is to sense the range RR from target 906 to receiver 904. This system primarily achieves this by sensing the total range RR traveled by the transmitted signal 908 and echo signal 910. sum The amount of time spent determines the range RR, the total distance R. sum It is the sum of RT and RR:

[0133] R sum =R T +R R (Equation 1)

[0134] Total distance R sum An ellipsoid (also known as an equal-range profile) is defined with its foci at the positions of transmitter 902 and receiver 904. This ellipsoid represents the distance over a given total distance R. sum In this case, the radar system 900 can measure all possible locations of target 906. sum For example, if perfect timing synchronization between transmitter 902 and receiver 904 can be assumed, then simply measuring the time duration T between the moment transmitter 902 transmits the transmitted signal 908 and the moment receiver 904 receives the echo signal 910 is sufficient. sum It will be easy. The time duration is T. sum Multiplying this by the speed of the signal through free space (e.g., approximately c = 3 * 908 m / s) will give R. sum Therefore, the ellipsoid of all possible locations of target 906 can be determined by measuring the "time of flight" T of the bistatic radar signal. sum To obtain.

[0135] According to some embodiments, the distance R sum Measurements can be performed without tight time synchronization between transmitter 902 and receiver 904. In one embodiment, a line-of-sight (LOS) signal 912 can be transmitted from transmitter 902 to receiver 904. That is, while transmitter 902 is transmitting a transmit signal 908 toward target 906, transmitter 902 can also transmit the LOS signal 912 toward receiver 904. According to a specific embodiment, transmit signal 908 can correspond to the main lobe of a transmit antenna beam pattern transmitted from transmitter 902, while LOS signal 912 corresponds to a sidelobe of the same transmit antenna beam pattern transmitted from transmitter 902.

[0136] Receiver 904 receives both echo signal 910 and LOS signal 912, and can use the timing of receiving these two signals to measure the total distance Rsum using the following formula:

[0137]

[0138] Here, T Rx_echo is the time of receipt of the echo signal 910. T RxLOS is the time of receipt of the LOS signal 912. As mentioned, c = 3*108meters / second is the speed of a signal through free space. L is the distance between the transmitter 902 and the receiver 904. Once R sum is found, it can be used to calculate the target range RR (i.e., the distance between the target 906 and the receiver 904) using the following equation:

[0139]

[0140] The bistatic radar system 900 can also be used to determine the angle of arrival (AoA) Θ R at which the echo signal 910 is received by the receiver 904. This can be done in various ways. One way is by using an antenna array at the receiver 904 to estimate Θ R . The antenna array, which includes multiple antenna elements, can operate as a programmable directional antenna that can sense the angle at which a signal is received. Thus, the receiver 904 can employ the antenna array to sense the angle of arrival of the echo signal 910. Another way for estimating Θ R involves multilateration. Multilateration refers to determining the intersection of two or more curves or surfaces that represent possible locations of a target. For example, FIG. 9 The bistatic radar system 900 shown in FIG. 1 can define a first ellipsoidal surface that represents possible locations of the target 906, as previously described. A second bistatic radar system with differently located transmitters and / or receivers can define a second, different ellipsoidal surface that also represents possible locations of the target 906. The intersection of the first ellipsoidal surface and the second ellipsoidal surface can reduce the possible location(s) of the target 906. In three-dimensional space, generally four such ellipsoidal surfaces will be needed to reduce the possible locations to a single point, thereby identifying the location of the target 906. In two-dimensional space (e.g., assuming all transmitters, receivers, and targets are confined to the earth), generally three such ellipsoidal surfaces (ellipsoidal surfaces reduce in dimension to elliptical curves for two-dimensional space) will be needed to reduce the possible locations to a single point, thereby identifying the location of the target 906. Multilateration can also be achieved in a similar manner using multistatic radar systems instead of multiple bistatic radar systems.

[0141] In addition, the bistatic radar system 900 can also be used to determine a Doppler frequency associated with the target 906. From the perspective of the receiver 904, this Doppler frequency represents the relative velocity of the target 906 - i.e., the speed at which the target 906 is approaching / leaving the receiver 904. For a stationary transmitter 902 and a stationary receiver 904, the Doppler frequency of the target 906 can be calculated as:

[0142]

[0143] Here, f D is the Doppler frequency, v is the velocity of the target 906 relative to a fixed frame of reference defined by the stationary transmitter 902 and receiver 904. β is the angle formed between the transmitted signal 908 and the echo signal 910 at the target 906. δ is the angle between the velocity vector v and the central ray (half-angle) defined within the angle β.

[0144] In FIG. 9 , the fixed frame of reference is defined with respect to the stationary transmitter 902 and the stationary receiver 904. Specifically, a baseline of length L can be drawn between the transmitter 902 and the receiver 904. This baseline can extend out from the transmitter 902 and the receiver 904. One or more normals can be drawn perpendicular to the baseline. The transmit angle θ T may be defined with respect to the normal drawn from the position of the transmit angle 902. The receive angle θ R may be defined with respect to the normal drawn from the position of the receiver 904, which is referred to above as the angle of arrival.

[0145] As previously mentioned, the bistatic radar system 900 can be operated to sense targets in two-dimensional space or three-dimensional space. An additional degree of freedom is introduced in the case of three-dimensional space. However, the same basic principles apply and similar calculations can be performed.

[0146] FIG. 10 An implementation of a bistatic radar system 900 in a wireless communication system in accordance with an embodiment of the disclosure is illustrated. The wireless communication system can include as FIG. 10The wireless communication system 1000 is shown in the diagram. The wireless communication system 1000 may include numerous transmit / receive points (TRPs) that, together with other devices, provide signal transmission and / or reception. Examples of TRPs within the wireless communication system 1000 include base stations 1002 and 1004, which provide wireless communication for user equipment (UEs) such as nearby vehicles requiring wireless data communication, wirelessphones, wearable devices, personal access points, and a wide range of other types of user equipment. For example, base stations 1002 and 1004 may be configured to support data communication with the UE by transmitting / receiving data symbols to / from the UE. Resources within the wireless communication system 1000 (such as base stations 1002 and 1004) can thus be used to serve a "dual mission," supporting not only wireless communication operation but also bistatic and / or multistatic radar operation. The wireless communication system 900 may be a cellular communication system.

[0147] For example, base station 1002 and base station 1004 can be used as... FIG. 9 The bistatic radar system 900 shown includes a transmitter 902 and a receiver 904. Base station 1002 transmits a transmitted signal 1008, which is reflected from target 906 and becomes an echo signal 1010 received by base station 1004. Base station 1004 can also receive a line-of-sight (LOS) signal 1012 from base station 1002. By receiving both the LOS signal 1012 and the echo signal 1010, RX base station 1004 can measure the reception time T associated with receiving the LOS signal 1012 and the echo signal 1010, respectively. Rx_echo With T RxLOS The value of the time difference between them. For example, RX base station 1004 can cross-correlate the received LOS signal 1012 with the received echo signal 1010 (such as by mixing the two signals in analog or digital form) to obtain a value representing the time difference (T). Rx_echo -T RxLOS The value of ) can be used to calculate the total distance R. sum Total distance R sum This can then be used to define an ellipsoid, which, along with other information, can be used with previously obtained information about... FIG. 9 One or more techniques discussed are used to determine the target range R associated with target 1006. R Angle of arrival (AoA)θ R And / or Doppler frequency.

[0148] Here, the target 906 can be (but is not necessarily) a UE being supported by the wireless communication system 1000. In some instances, the target 906 can be a UE configured to use the base stations of the wireless communication system 1000 to transmit and receive wireless signals carrying voice, text, and / or wireless data. In other instances, the target 906 can simply be a remote object within the bi-static radar range of the base station 1002 and the base station 1004, but otherwise unrelated to the wireless communication functions of the system 1000.

[0149] In FIG. 10 the bi-static example shown in FIG. 10, the transmitter is referred to as the TX base station 1002 and the receiver is referred to as the RX base station 1004. More generally, the TX base station 1002 can be referred to as a TX TRP and the RX base station 1004 can be referred to as an RX TRP. Here, the “TX” and “RX” refer only to the fact that the base station 1002 is used to transmit the radar transmit signals 1008 and the base station 1004 is used to receive the radar return signals 1010. The terms “TX” and “RX” in this context do not limit the operation of the base stations 1002 and 1004 to serve other functions, e.g., to serve as a transmitter and / or receiver in other bi-static or multi-static radar operations (beyond those FIG. 9 illustrated in FIG. 10). While FIG. 10 a simple bi-static radar system is illustrated, a multi-static radar system can also be implemented in a similar manner within a wireless communication system. Also, while FIG. 10 a simple example in two-dimensional space is illustrated, the same operations can be extended to three-dimensional space.

[0150] Implementing a bistatic or multistatic radar system within a wireless communication system according to the embodiments of this disclosure offers numerous benefits. One particular benefit is the flexible utilization of bandwidth allocated for wireless communication. An example of the wireless communication system 1000 is a cellular communication system. For example, according to one embodiment, the wireless communication system 1000 may comply with the “5G” standard introduced in Release 15 of the 3rd Generation Partnership Project (3GPP) specification. The ever-increasing bandwidth allocated to current and future wireless communication systems (including 5G and beyond 5G) can be utilized to transmit bistatic and multistatic radar signals. Thus, radio frequency (RF) sensing (e.g., radar) can be achieved by utilizing available wireless RF spectrum resources. For example, one or more of the transmitted signal 1008, the echo signal 1010, and / or the LOS signal 1012 may occupy bandwidth within a portion of the radio frequency (RF) spectrum allocated to the wireless communication system 1000 for data communication. Another example of the wireless communication system 1000 is a Long Term Evolution (LTE) wireless communication system. Other examples of the wireless communication system 1000 include wireless local area networks (WLANs), wireless wide area networks (WWANs), small cell-based wireless communication systems, millimeter wave-based communication systems, and other types of communication systems including TRPs.

[0151] Furthermore, the inherent benefits of bistatic and multistatic radar systems can be realized through existing widespread networks of transmitters and receivers in the form of well-placed wireless base stations. Compared to monostatic radar systems, bistatic or multistatic radar systems mitigate self-interference by having physically separate transmitter and receiver equipment. Wireless base stations (such as...) FIG. 10 The base stations 1002 and 1004 shown already exist and cover a vast geographical area where users, vehicles, and other objects of interest are likely to be present. Such wireless base stations are sufficiently dispersed, and as a result, provide the opportunity to select appropriately positioned base stations for use as transmitters and receivers for bistatic and multistatic radar operations.

[0152] A major challenge arising in the development of bistatic or multistatic radar systems is the coordination between the transmitters and receivers(s). Various techniques for addressing such coordination problems are provided through embodiments of this disclosure, as discussed in the following sections.

[0153] According to some embodiments, a "radar server" can be implemented to support the operation of one or more bistatic and / or multistatic radar systems implemented within a wireless communication system. Here, a "radar controller" can be implemented as a combination of hardware and / or software resources residing within the wireless communication network. Thus, the radar controller can be defined as a functional block, facility, or node for, for example, configuring and / or controlling parameters relied upon by the TX and RX base stations participating in the operation of the bistatic and / or multistatic radar.

[0154] FIG. 11 is a block diagram of a wireless communication system 1100 that can include a radar controller according to an embodiment of the disclosure. The wireless communication system 1100 includes a core network (CN) 1102, a radio access network (RAN) 1104, and one or more user equipment (UE) 1106. In one embodiment, a radar controller 1108 can be implemented within the CN 1102. The CN 1102 provides connectivity to the Internet and application services for the system 1100. The CN 1102 can be implemented using various computing resources, which can include memory and one or more processors executing an operating system and applications including programmed instructions. In a particular embodiment, the radar controller 1108 can be implemented within the computing resources of the CN 1102.

[0155] In another embodiment, a radar controller 1110 can be implemented within the RAN 1104. For example, the RAN 1104 can include base stations 1002-1004. Each of the base stations 1002-1004 can include transmitter and receiver hardware, such as antennas, antenna elements, cables, physical tower structures, modems, encoders / decoders, networking equipment, computing resources, and other components. The computing resources associated with each base station can include memory and one or more processors executing an operating system and applications including programmed instructions. In a particular embodiment, the radar controller 1110 can be implemented within the computing resources of one or more of the base stations 1002-1004.

[0156] The radar controller 1108 (or 1110) can be implemented in a radio access network (RAN), a core network (CN) 1110, or elsewhere in a wireless communication system, such as the cellular communication system 1100. The radar controller 1108 (or 1110) need not be a dedicated server. For example, the radar controller 1108 (or 1110) can be a general-purpose server, a positioning server, an advanced driver assistance server, a tracker server, or another server that provides different functionality. Moreover, the radar controller 1108 (or 1110) can (but need not) be operated or owned by a network operator. The radar controller 1108 (or 1110) can be a network-independent server (e.g., a third-party server).

[0157] Regardless of where implemented, the radar controller 1108 (or 1110) can be communicatively coupled to transmission-reception points (TRPs) within the RAN 1104, such as the base stations 1002 and 1004, via one or more interfaces. The one or more interfaces can include point-to-point interfaces. One example of such a point-to-point interface is an interface that implements an Internet Protocol (IP) communication protocol over a wired network (e.g., a “backhaul” network).

[0158] In such a case, the CN 1102 can be a 5G core node (5G CN), the RAN 1104 can be a 3GPP Next Generation Radio Access Network (NG RAN), and each of the base stations 1002 and 1004 can be a “gNodeB” or “gNB.” In such a case, the CN 1102 can be a 5G core node (5G CN), the RAN 1104 can be a 3GPP Next Generation Radio Access Network (NG RAN), and each of the base stations 1002 and 1004 can be a “gNodeB” or “gNB.”

[0159] FIG. 12 An example of a list of radar configuration parameters 1200 provided by the radar controller 1108 (or 1110) to the TX base station 1002 and the RX base station 1004 for a bistatic or multistatic radar measurement session is shown in accordance with an embodiment of the present disclosure. Here, the radar measurement session can include one or more radar signal transmissions / receptions associated with obtaining range, Doppler, or angle estimates about a target. An example of such a radar measurement session can be a “chirp” sequence of frequency-modulated continuous wave (FMCW) radar signals transmitted by the TX base station and a corresponding “chirp” sequence of FMCW radar signals received by the RX base station.

[0160] As shown in FIG. 12 The list of radar configuration parameters 1200 can include a number of entries, which can include values for parameters such as a radar session ID, a TX base station ID, a RX base station ID, TX / RX timing parameters, Doppler parameters, a radar waveform type, a radar signal center frequency, a radar signal bandwidth (BW), a radar period, a radar repetition factor, and a linear frequency modulation (LFM) frequency slope. These parameters are given for illustrative purposes, and the entries in the list of configuration parameters for any given radar system implemented within a wireless communication system can differ from the example shown in FIG. 12

[0161] Referring again to FIG. 12 , the radar session ID identifies a particular radar measurement session. The TX base station ID identifies a particular base station in the wireless communication system as the transmitter of radar transmit signals. The RX base station ID identifies a particular base station in the wireless communication system as the receiver of radar echo signals reflected from a target. FIG. 12 ​The example shown in FIG. 13 assumes a basic bistatic radar measurement session using one transmitter and one receiver. The ID of an additional transmitter and / or receiver(s) can be included for a multistatic radar measurement session. The TX / RX timing parameters can contain multiple entries and include a sub-list (described in more detail in a later section). A link or pointer can be provided to the sub-list. Similarly, the Doppler parameters can contain multiple entries and include a sub-list (for which a link or pointer can be provided). The radar waveform type specifies the type of waveform to be used. Different tuple values can correspond to different waveform types. By way of example only, the following values and corresponding waveforms can be provided:

[0162] “0” = FMCW

[0163] “1” = Positioning Reference Signal (PRS)

[0164] “2” = Single Sideband Modulation (SSB)

[0165] “3” = Tracking Reference Signal (TRS)

[0166] “4” = Demodulation Reference Signal (DMRS)

[0167] “5” = Channel State Information Reference Signal (CSI-RS).

[0168] Various waveforms can be selected. Some waveforms, such as FMCW, can be specifically associated with radar system operations. However, other waveforms, such as PRS, SSB, TRS, DMRS, and CSI-RS, can be associated with wireless system operations. Thus, in accordance with embodiments of the present disclosure, waveforms already existing in a wireless communication system can be opportunistically used as radar signal waveforms.

[0169] The radar controller 1108 (or 1110) can specify one or more parameters associated with the selected reference signal. The reference signal can be defined by selecting a waveform type, such as those listed above. In addition, the reference signal can be defined by specifying one or more other attributes. For example, the radar configuration parameter list 1200 or other configuration parameters can be used to specify such attributes. Referring back to FIG. 12 The radar signal center frequency specifies the center frequency of the radar transmit signal. By way of example only, FIG. 12 The center frequency 79 GHz is shown in FIG. 13. Thus, the center frequency in this example falls within the spectrum allocated for the wireless communication system 1000 (e.g., within the 5G spectrum, which ranges from 300 MHz to 100 GHz). The center frequency of the radar echo signal can exhibit a Doppler shift away from the radar center frequency. Such Doppler shifts are discussed in more detail in a later section. The radar signal bandwidth (BW) specifies the bandwidth of the transmitted radar signal. By way of example only, FIG. 12Bandwidth 2 GHz is shown in the middle. Radar return signals are expected to have the same bandwidth. The radar repetition factor specifies the number of times a radar waveform can repeat in the specified radar session (e.g., in radar session 12345678). In this example, the waveform repeats 10 times. The LFM frequency slope specifies the slope or rate of change of the frequency of a linear frequency modulated (LFM) radar waveform. Here, the slope is 100 MHz / µs. One type of LFM waveform is the previously mentioned FMCW waveform.

[0170] In summary, FIG. 13 The radar session specified in the middle can utilize FMCW waveforms that form a "chirp" that repeats 10 times for a total duration of 200 µs. Each chirp can have a duration of 20 µs during which the center frequency of a continuous wave (CW) signal is linearly increased from 79 GHz to 81 GHz at a rate of 100 MHz / µs. Even though the CW signal has a very narrow bandwidth, the effective bandwidth for the entire sweep of the FMCW signal would be 2 GHz. These or other characteristics of the reference signal (in this case, the FMCW reference signal) can be specified as one or more parameters provided by the radar controller 1108 (or 1110).

[0171] Embodiments of the present disclosure can utilize the wireless communication system 1000 to estimate certain physical properties in a radar system. For example, the distance L between the TX base station 1002 and the RX base station 1004 is an important number that can be useful in the calculation of the target range RR and other values. The resources available within the wireless communication system 1000 can provide different ways for determining L. One possibility is to use the known locations of the TX base station 1002 and the RX base station 1004. Such location information can be available in an almanac of collected physical descriptions for all base stations available for use within the wireless communication system 1000. Another possibility is to use GNSS (e.g., GPS) reports from the base stations, such as the TX base station 1002 and the RX base station 1004. Typically, GNSS reports include the location of the base station. Using the accurate longitude and latitude information available for the base station locations, the distance L between the TX base station 1002 and the RX base station 1004 can be calculated. Yet another possibility is to use inter-base station positioning signals to obtain the location fix of the TX base station 1002 and the RX base station 1004. For example, positioning signals, such as positioning reference signals (PRS), can be transmitted and received between base stations according to positioning techniques adapted for New Radio / 5G standards. Such inter-base station positioning signals can be used to determine the positioning fix of the TX base station 1002 and the RX base station 1004, and the distance L between them can be determined therefrom.

[0172] FIG. 13An example of a TX / RX timing sub-list 1300 according to embodiments of the present disclosure is shown. In one particular embodiment, the TX / RX timing sub-list 1300 can simply be merged as an additional entry in the radar configuration parameter list 1200. In another particular embodiment, the TX / RX timing sub-list 1300 can be a separate but linked sub-list.

[0173] The timing parameters specified in the TX / RX timing sub-list 1300 rely on some degree of timing synchronization between the TX base station 1002 and the RX base station 1004. Such TX / RX timing synchronization is important for numerous reasons. If the RX base station 1004 starts “listening” just in time (i.e., at or just shortly before the arrival of the first expected signal (which can be the LOS signal 1012 or the echo signal 1010)), the performance of the radar system can be greatly improved. If the RX base station 1004 starts listening too early, the system can turn on equipment such as intermediate frequency (IF) receive hardware too early, wasting power and computational resources and increasing the false alarm probability of the radar system. If the RX base station 1004 starts listening too late, the system can miss receiving the LOS signal 1012 or the echo signal 1010. If some degree of timing synchronization can be achieved between the TX base station 1002 and the RX base station 1004, with knowledge of when the transmit signal 1008 is sent from the TX base station 1002, a calculation can be made to predict the arrival time (with some degree of acceptable uncertainty) of the LOS signal 1012 or the echo signal 1010 at the RX base station 1004. In this way, the RX base station 1004 can be controlled to start “listening” just in time to reduce unnecessary power and computational resource waste and to minimize false alarms while ensuring that the LOS signal 1012 and the echo signal 1010 are not missed.

[0174] Aspects of the present disclosure advantageously utilize the wireless communications system 1000 to meet such radar TX / RX timing synchronization requirements. For example, the wireless communications system 1000 can comprise a 5G system (e.g., system 1100) that guarantees that the timing synchronization error between any two base stations does not exceed some amount of time. By way of example only, a 5G system can utilize orthogonal frequency division multiplexing (OFDM) signals for data communications, and can guarantee that the timing synchronization error between any two base stations does not exceed the duration of a cyclic prefix (CP) of the OFDM signals. The CP is a guard band in time that separates consecutive data symbols and provides protection against inter-symbol interference (ISI). For a subcarrier channel of 60 kHz, the CP duration can be, for example, 1.69 μβ. Thus, the wireless communications system 1000 in this case can guarantee that the timing error between any two base stations will not exceed 1.69 μβ. With such timing synchronization guarantees, the radar controller 1108 (or 1110) can be able to more effectively control the timing with respect to when the TX base station 1002 transmits the transmit signal 1008 and when the RX base station 204 begins listening for the LOS signal 1012 and the return signal 1010.

[0175] Referring back to FIG. 14 The TX / RX timing sub-list 1300 can include the radar session ID (previously discussed), the TX transmission time, the expected receive time, and the expected receive time uncertainty. The radar controller 1108 (or 1110) can provide all or relevant portions of the TX / RX timing sub-list 1300 to the TX base station 1002 and the RX base station 1004. For example, the radar controller 1108 (or 1110) can provide the TX transmission time to the TX base station 1002, which in this example is specified as 20,000.00 μβ. In response, the TX base station begins transmitting the transmit signal 1008 at time 20,000.00 μβ. By way of example only, the value "20,000.00 μβ" can correspond to the time elapsed since the last "tick" of a periodic reference event / signal used to synchronize timing across the entities (e.g., all base stations and other equipment) within the wireless communications network 1000.

[0176] The radar controller 1108 (or 1110) can also provide the expected receive time to the RX base station 1002, which in this example is specified as 20,133.33 μβ. The radar controller 1108 (or 1110) can be able to calculate the expected receive time in different ways. In one embodiment, the expected receive time can be estimated by assuming that the LOS signal 1012 is likely to arrive at the RX base station before the return signal 1010, which is a valid assumption in many cases. Given this assumption, the expected receive time can be estimated as the TX transmission time plus the amount of time it is expected to take for the LOS signal 1012 to traverse the distance L:

[0177] Expected receive time = L / c + TX transmission time (Eq. 5)

[0178] The radar controller 1108 (or 1110) can also provide an expected receive time uncertainty, which in this example is specified as a pair of values: [upper limit, lower limit]. The lower limit can simply be the negative of the network synchronization error. By way of example only, the network synchronization error can be 1.69 ps. The upper limit can include two components. A first component of the upper limit can correspond to the signal propagation time associated with the maximum possible distance of a detectable target. In one embodiment, such maximum distance L Max can be specified as part of the link budget. As such, the first component of the upper limit can be expressed as L Max / c = L / c. The second component of the upper limit can simply be the positive of the network synchronization error, which in this example is specified as 1.69 ps. Accordingly, the expected receive time uncertainty can be expressed as:

[0179] Expected receive time uncertainty

[0180] = [lower limit, upper limit]

[0181] = [-network synchronization uncertainty, L max / c - L / c + network synchronization error] (Eq. 6)

[0182] There can also be flexibility in the manner in which these and other configuration parameters are specified and communicated. For example, to specify the upper limit of the expected receive time uncertainty, it can be sufficient for the radar controller 1108 (or 1110) to simply send the value “L max / c + network synchronization error” to the RX base station 1004 (especially if the term L / c is already known locally at the RX base station 1004).

[0183] In response, the RX base station 1004 can begin “listening” (i.e., begin sensing the LOS signal 1012 and the echo signal 1010) within a time window specified by:

[0184] Expected receive time + expected receive time uncertainty

[0185] = expected receive time + [lower limit, upper limit]

[0186] = [Lc + TX transmission time - network synchronization uncertainty,

[0187] L max / c + TX transmission time + network synchronization error] (Eq. 7)

[0188] The preceding text explained the TX / RX timing parameters for a bistatic radar session (which involves one TX base station and one RX base station). In practice, many such bistatic radar sessions (and multistatic radar sessions) can be specified in a similar manner. For each unique path L (i.e., a unique TX and RX station pair), the radar controller 1108 (or 1110) can specify a different set of TX / RX timing parameters. In a simple multistatic scenario with one transmitter and multiple receivers, the unique pairs can share a common TX base station but have different RX base stations. In such cases, a TX transmission time and multiple sets of expected reception times and expected reception time uncertainties can be specified.

[0189] FIG. 14 Examples of Doppler sublists 1400 according to various embodiments of the present disclosure are shown. In one specific embodiment, the Doppler sublist 1400 may simply be merged into additional entries in the radar configuration parameter list 1200. In another specific embodiment, the Doppler sublist 1400 may be a separate but linked sublist.

[0190] The Doppler sublist 1400 is primarily used to estimate Doppler frequency shift and Doppler spread for the benefit of the RX base station 1004. For example... FIG. 14 As shown, the Doppler sublist 1400 may include (as previously discussed) the radar session ID, the expected Doppler shift value, and the expected Doppler spread value. The radar controller 1108 (or 1110) typically provides these frequency domain parameters to improve the performance of the RX base station 1004. The target 906 is likely to be moving rapidly, which can introduce a large Doppler shift and / or Doppler spread. By providing the Doppler sublist 1400, the radar controller 1108 (or 1110) can dynamically configure the "expected Doppler shift" and "expected Doppler spread" assumed by the RX base station 1004.

[0191] For example, in capture mode, the Doppler sublist 1400 can specify larger values ​​for the expected Doppler shift and expected Doppler spread. This allows the RX base station 1004 to receive signals over a wider Doppler frequency range, thereby improving the detection rate. This is just an example. FIG. 12 The expected Doppler shift value is specified as 80,000 m / s and the expected Doppler spread is specified as 10,000 m / s.

[0192] In contrast, in tracking mode, the Doppler sublist 1400 can specify finer and narrower values. These values ​​can be based on the measurement history already performed. A finer set of Doppler parameters can be focused on a specific target. An instance of the Doppler sublist 1400 can be specified for each target being tracked. Thus, a particular RX base station 1004 can receive multiple Doppler sublists 1400 corresponding to multiple targets.

[0193] FIG. 15 、 13 The specific parameters shown in FIGS. 14 are described for illustrative purposes. Depending on the implementation, there can be deletions or additions of certain parameters, and different parameters can be specified at the same time. Nonetheless, according to embodiments of the present disclosure, configuration parameters for the TX base station(s) and / or RX base station(s) in a bistatic or multistatic radar system can be provided by a radar controller located within an entity in a wireless communication network, such as a core network (CN) or a radio access network (RAN).

[0194] FIG. 16 A cellular reference signal resource configuration 1500 for Doppler estimation according to an aspect of the present disclosure is illustrated. In particular, the cellular reference signal resource configuration 1500 is associated with reference signals that span sixteen (16) 0.5ms slots, some of which correspond to downlink “D” slot formats, and some of which correspond to special “S” slot formats. In the case of spanning X ms, the Doppler resolution can be characterized as 1000 / X Hz. In the example of FIG. 16 In the example of 125Hz Doppler resolution (e.g., in the case of spanning sixteen 0.5ms slots, X = 8ms, and 1000 / 8 = 125), and a maximum resolvable Doppler of 2000Hz (e.g., in the case of spanning a single 0.5ms slot, X = 0.5ms, and 1000 / 0.5 = 2000).

[0195] It can be difficult to implement RF radar signals that also serve as reference signals (e.g., DL-PRS, CSI-RS, etc.). For example, radar signals for tracking targets can need to be relatively long in duration per occasion or instance (e.g., due to high path loss on NLOS paths to the Rx gNB). In some designs, radar signals can only be available sporadically (e.g., aperiodic). In some designs, multiple targets can need to be tracked or detected, and delay estimation as well as Doppler estimation can be coupled.

[0196] In terms of slot configuration, downlink (DL) slots, uplink (UL) slots, or flexible (FL) slots can be used to communicate the multistatic radar signals. In some designs, a Tx gNB that transmits the multistatic radar signals can use DL slots, while a Rx gNB that receives and measures the multistatic radar signals can use UL slots.

[0197] FIG. 10 An interference scenario 1600 in a wireless communication system according to an embodiment of the present disclosure is illustrated. FIG. 17 Similar to 2 symbols , except further depicting a UE 302. In4 symbols In the middle, since the LOS signal 1012 and the echo signal 1010 are being received on the UL slot, there can be a concurrent interfering UL transmission from the UE 302, as shown with respect to the UL signal 1605. In this case, the UL signal 1605 can increase interference to the LOS signal 1012 and / or the echo signal 1010 at the base station 1004, the LOS signal 1012 and / or the echo signal 1010 can increase interference to the UL signal 1605 at the base station 1004, or both. In some designs, the base station 1004 can attempt to avoid scheduling the UL signal 1605 to mitigate potential interference.

[0198] 6 symbols An interference scenario 1700 in a wireless communication system is illustrated in accordance with another embodiment of the present disclosure. 12 symbols Similar to comb-2 , except further depicting the UE 302. In comb-4 In the middle, since the LOS signal 1012 and the echo signal 1010 are being received on the UL slot, there can be a concurrent interfering UL transmission from the UE 302, as shown with respect to the UL signal 1605. In this case, the UL signal 1605 can increase interference to the LOS signal 1012 and / or the echo signal 1010 at the base station 1004, the LOS signal 1012 and / or the echo signal 1010 can increase interference to the UL signal 1605 at the base station 1004, or both. In some designs, the base station 1004 can attempt to avoid scheduling the UL signal 1605 to mitigate potential interference.

[0199] DL-PRS resources can be transmitted by a TRP using various transmission schedules (also referred to as transmission modes), for example:

[0200] N / A N / A comb-6 N / A N / A {0,1} {0,1,0,1} {0,1,0,1,0,1} {0,1,0,1,0,1,0,1,0,1,0,1} comb-12 N / A {0,2,1,3} N / A {0,2,1,3,0,2,1,3,0,2,1,3}} N / A Table 2: PRS resource configuration examples FIGS. 18A-18H {0,3,1,4,2,5} {0,3,1,4,2,5,0,3,1,4,2,5} FIGS. 18A-18H FIG. 18A FIG. 18B FIG. 18C {0,6,3,9,1,7,4,10,2,8,5,11}

[0201] FIG. 18D

[0202] FIG. 18E DL-PRS resource configurations are illustrated in accordance with aspects of the present disclosure. In FIG. 18F DL-PRS resource configurations, the list denotes different symbols, the rows denote different subcarriers, and the dark boxes denote sounding resource elements (symbol-subcarrier combinations) for a TRP. Unsounded resource elements can be sounded by one or more other TRPs.

[0203] FIG. 18GDL-PRS resource configuration 1802 is shown for a comb-2, 2 symbol resource, with a symbol offset of three symbols in a slot containing 14 symbols, each with 12 subcarriers. FIG. 18H DL-PRS resource configuration 1804 is shown for a comb-4, 4 symbol resource. FIGS. 18A-18H DL-PRS resource configuration 1806 is shown for a comb-6, 6 symbol resource. Table 2 DL-PRS resource configuration 1812 is shown for a comb-12, 12 symbol resource. FIG. 19 DL-PRS resource configuration 1814 is shown for a comb-2, 12 symbol resource. FIG. 20 DL-PRS resource configuration 1816 is shown for a comb-4, 12 symbol resource. FIG. 9 DL-PRS resource configuration 1818 is shown for a comb-2, 6 symbol resource. FIG. 21 DL-PRS resource configuration 1820 is shown for a comb-6, 12 symbol resource. FIG. 22 Each of the transmission modes in has at least one sounding RE in each of the subcarriers, and is thus a fully staggered transmission mode. If each DL-PRS resource configuration (or mode) corresponds to a PRS resource, each PRS resource is a fully staggered resource. A DL-PRS resource can be configured in any DL or FL symbol of a slot that is configured by higher layers. A constant energy per resource element (EPRE) can be used for all REs of a given DL-PRS resource.

[0204] A PRS can comprise a PRS resource, a PRS resource set, or a PRS resource of a frequency layer. A DL PRS positioning frequency layer (or simply frequency layer) is a collection of DL PRS resource sets with common parameters configured by the parameter DL-PRS-PositioningFrequencyLayer. Each frequency layer has the same DL-PRS subcarrier spacing (SCS) for the DL PRS resource sets and DL PRS resources in that frequency layer. Each frequency layer has the same DL PRS cyclic prefix (CP) type for the DL PRS resource sets and DL PRS resources in that frequency layer. Also, a DL PRS point A parameter defines the frequency of a reference resource block, where DL PRS resources belonging to the same DL PRS resource set have the same point A, and all DL PRS resource sets belonging to the same frequency layer have the same point A. The PRS resource sets of a frequency layer also have the same starting PRB (and center frequency) and the same comb size value.

[0205] As used herein, a positioning session can include multiple PRS instances, where each PRS instance includes a PRS resource set. A PRS resource set in turn includes multiple PRS resources. For example, in some implementations, a positioning session can span approximately 20 seconds, while each PRS instance can span approximately 160 ms. DL PRS resources can be repeated to facilitate Rx beam sweeping across different repetitions, combining the gain of extended coverage and / or intra-instance muting. In some designs, a PRS configuration can support a number of repetition counts (PRS-ResourceRepetitionFactor) and a number of time gaps (PRS-ResourceTimeGap), as shown in Table 2:

[0206]

[0207] FIG. 22

[0208] FIG. 21 A PRS resource distribution 1900 according to an embodiment of the disclosure is illustrated. The PRS resource distribution 1900 reflects a DL-PRS resource set with 4 resources, PRS-ResourceRepetitionFactor of 4, and PRS-ResourceTimeGap of 1 slot.

[0209] FIG. 23 A PRS resource distribution 2000 according to another embodiment of the disclosure is illustrated. The PRS resource distribution 2000 reflects a DL-PRS resource set with 4 resources, PRS-ResourceRepetitionFactor of 4, and PRS-ResourceTimeGap of 4 slots.

[0210] The time interval between reception of the LOS signal transmitted by the Tx and reception of the target echo can be used to measure the distance and R sum . Thus, small-scale synchronization errors between Tx / Rx do not introduce estimation errors. In classical radar systems, the same / common transmitted radar signal propagates through the channel. The Rx then estimates the ToA difference between the LOS path and the echo path.

[0211] In some cases, it is not optimal to use the same radar reference signal to estimate the ToA in both the LOS and target echo paths for various reasons. First, a single wide angle beam can be applied to the radar Tx waveform, which reduces the coverage of the system (e.g., a more focused beam can provide more coverage, but can not travel along both the LOS and echo paths). Second, digital beamforming can enable two concurrent beams, one for the LOS direction and one for the transmitter-target direction. However, this increases the number of Tx antennas at the gNB for concurrent transmission along both paths (two beams), doubling the antenna cost. Third, for millimeter wave systems using analog beamforming, it is also possible to maintain two concurrent beams. However, this requires at least two antenna panels for each sector, one for the LOS beam and one for the transmitter-target direction, doubling the antenna panel cost.

[0212] Regardless of which symbol is used for the transmission / reception of the target radar waveform, a reference radar signal can be transmitted so that the gNB Rx will be able to determine the “baseline”, denoted as L in FIG. 23 The gNB is static and does not need to transmit long signals to learn the Doppler information, as in the case where a moving target is being tracked by the target radar waveform. The radar controller is aware of the location of the gNB, so it can generate the need for transmission / reception of signals to learn the baseline, determining the Tx / Rx / network synchronization ambiguity. In some designs, the “baseline” can need to be estimated (or calibrated) at some interval, which can depend on the degree of time-domain ambiguity and how frequently such ambiguity is changing (e.g., time-domain drift).

[0213] One or more aspects of the disclosure relate to implementing different transmission configurations for a reference radar signal and at least one target radar signal. Such aspects can provide various technical advantages, such as increasing coverage (e.g., via beamforming), improving target tracking performance, and so forth.

[0214] FIG. 21 An exemplary communication process 2100 in accordance with aspects of the disclosure is illustrated. In an aspect, process 2100 can be performed by a radar controller, which as mentioned above can be integrated with a RAN component such as BS 304 or a core network component or an external server such as network entity 306. In some designs, the radar controller can be integrated with a first base station or a second base station as described above, in which case any exchange of data between the radar controller and the respective base station would correspond to an internal transmission of data, rather than a signal(s) communicated across a network.

[0215] At 2110, the radar controller (e.g., processing system 384 or 394, radar component 388 or 389, etc.) determines a first transmission configuration for a reference radar signal on a first link from the first base station to the second base station. In some designs, the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station. In other designs, the first transmission configuration can be used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first base station to the second base station (e.g., the first transmission can be used to derive a time difference between the two base stations and / or to calibrate their timing clocks without necessarily going through the most direct link).

[0216] At 2120, the radar controller (e.g., processing system 384 or 394, radar component 388 or 389, etc.) determines a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal being used to sense at least one target, the first transmission configuration being different than the second transmission configuration. In some designs, the at least one second link corresponds to at least one NLOS link, an indirect link, or a non-EToA link from the first base station to the second base station. For example, the second link can generally be associated with a longer path (e.g., in terms of distance or propagation time) than the first link. In some designs, the at least one target radar signal can be transmitted after the reference radar signal (e.g., on a later symbol in the same time slot as the reference radar signal, in a TDM manner).

[0217] At 2130, the radar controller (e.g., data bus 382, network interface(s) 380 or 390, etc.) transmits the first transmission configuration to the first base station and the second base station.

[0218] At 2140, the radar controller (e.g., data bus 382, network interface(s) 380 or 390, etc.) transmits the second transmission configuration to the first base station and the second base station.

[0219] FIGS. 21-23 An example communication process 2200 in accordance with aspects of the present disclosure is illustrated. In an aspect, process 2200 can be performed by a first base station, such as BS 304. For example, with respect to FIGS. 21-23 The described first base station can correspond to the first base station described above with respect to FIGS. 21-23 In some designs, the radar controller can be integrated with the first base station as described above, in which case any data exchange between the radar controller and the first base station would correspond to an internal transmission of data, rather than a signal communicated across a network.

[0220] At 2210, the first base station (e.g., network interface(s) 380, data bus 382, etc.) receives, from the radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station.

[0221] At 2220, the first base station (e.g., network interface(s) 380, data bus 382, etc.) receives, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration.

[0222] At 2230, the first base station (e.g., transmitter 354 or 364, etc.) transmits the reference radar signal to the second base station on the first link in accordance with the first transmission configuration. In some designs, the reference radar signal is transmitted on a LOS, direct, or EToA link via a default beam (e.g., an ideal beam can be identified earlier and then set as the default beam).

[0223] At 2240, the first base station (e.g., transmitter 354 or 364, etc.) transmits the at least one target radar signal to the second base station on the at least one second link in accordance with the second transmission configuration. In some designs, the at least one target radar signal is transmitted on at least one NLOS link via a dynamically determined set of beams (e.g., due to target mobility). In some designs, the at least one second link corresponds to at least one NLOS, indirect, or non-EToA link from the first base station to the second base station. For example, the second link can generally be associated with a longer path (e.g., in terms of distance or propagation time) than the first link. In some designs, the at least one target radar signal can be transmitted after the reference radar signal (e.g., on a later symbol in the same time slot as the reference radar signal, in a TDM manner). In some designs, the at least one target radar signal can include multiple target radar signals targeting the same or different targets. In the case of different targets, R sum .

[0224] FIGS. 21-23 An exemplary communication process 2300 in accordance with aspects of the present disclosure is illustrated. In an aspect, process 2300 can be performed by a second base station, such as BS 304. For example, with respect to FIGS. 21-23 The described second base station can correspond to the second base station described above with respect to FIGS. 21-23 In some designs, the radar controller can be integrated with the second base station as described above, in which case any data exchange between the radar controller and the second base station would correspond to internal transmission of data, rather than signals communicated across a network.

[0225] At 2310, the second base station (e.g., network interface(s) 380, data bus 382, etc.) receives, from the radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to the second base station.

[0226] At 2320, the second base station (e.g., network interface(s) 380, data bus 382, etc.) receives, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration.

[0227] At 2330, the second base station (e.g., receiver 352 or 362, etc.) receives the reference radar signal from the first base station on the first link in accordance with the first transmission configuration. In some designs, the reference radar signal is received via a default beam (e.g., an ideal beam can be identified earlier and then set as the default beam) on a LOS, direct, or EToA link.

[0228] At 2340, the second base station (e.g., receiver 352 or 362, etc.) receives the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration. In some designs, the at least one target radar signal is received via a dynamically determined set of beams (e.g., due to target mobility) on at least one NLOS link. In some designs, the at least one second link corresponds to at least one NLOS, indirect, or non-EToA link from the first base station to the second base station. For example, the second link can generally be associated with a longer path (e.g., in terms of distance or propagation time) than the first link. In some designs, the at least one target radar signal can be transmitted after the reference radar signal (e.g., on a later symbol in the same time slot as the reference radar signal, in a TDM manner). In some designs, the at least one target radar signal can include multiple target radar signals targeting the same or different targets. In the case of different targets, R sum .

[0229] Referring to FIGS. 21-23In some designs, the first and second transmission configurations differ in subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type (e.g., QPSK-based or Zadoff-Chu-based sequences), number of ports (e.g., single port for the first transmission configuration, multiple ports for the second transmission configuration), bandwidth or frequency band (e.g., wider bandwidth for the second transmission configuration), frequency domain reference point, or a combination thereof. For example, the first transmission configuration can use point A as a reference point, while the second transmission configuration can be CC-starting or BWP-starting. In another example, the first transmission configuration can use a configured frequency domain reference point that is different from a configured frequency domain reference point of the second transmission configuration. This can occur due to a particular frequency being more suitable for sensing a target (e.g., better reflected by the target), while the first reference signal does not need to be optimized for sensing any target (e.g., only for earliest ToA estimation). For similar reasons, different frequency bands can be used.

[0230] Referring to FIGS. 21-23 In some designs, the first transmission configuration can configure fewer transmissions of the reference radar signal compared to the at least one target radar signal over a time period. For example, the first transmission configuration can configure periodic transmissions of the reference radar signal and the at least one target radar signal, and the reference radar signal can be associated with a longer periodicity compared to the at least one target radar signal. In some designs, the first base station can transmit an indication of a degree of time-domain drift (e.g., clock stability) between the first base station and the second base station, and the first transmission configuration can be associated with a periodicity based on the indication (e.g., if the time drift is above a threshold, then associated with a lower periodicity, so the reference radar signal is transmitted more frequently, if the time drift is below a threshold, then associated with a higher periodicity, so the reference radar signal is transmitted less frequently, etc.). In other designs, in addition to or instead of the time-domain drift indication, the first base station can transmit a periodicity recommendation (e.g., if the time drift is above a threshold, then recommend a lower periodicity, so the reference radar signal is transmitted more frequently, if the time drift is below a threshold, then recommend a higher periodicity, so the reference radar signal is transmitted less frequently, etc.).

[0231] Referring to FIG. 24In some designs, the first transmission configuration is associated with one or more target geographic areas that include the first base station (e.g., any gNB within the geographic area(s) will use the first transmission configuration), or the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station (e.g., the first base station can be provisioned with a numerology, or be aware of the locations of the TRP(s), etc.), or a combination thereof. For example, the first base station can identify the TRPs associated with the second base station to determine the first transmission configuration (e.g., different first transmission configurations can be used for reference radar signals transmitted by the same base station to different TRPs). In some designs, the TRPs can be identified in different ways, such as by a physical cell identifier (PhysCellID), a cell global identifier (CellGlobalID), etc., of the second base station.

[0232] Referring to FIGS. 21-23 In some designs, the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS). In other designs, the reference radar signal does not need to correspond to an existing signal at all, and a new reference signal type can be defined for this reference radar signal.

[0233] Referring to ​ In some designs, the first transmission configuration is associated with a shorter duration per reference radar signal instance compared to the second transmission configuration per target radar signal instance (e.g., because the first link can experience less path loss than the second link, etc.). In some designs, the reference radar signal can potentially be as small as one symbol or generally use a smaller number of symbols compared to the target radar signal(s).

[0234] Referring to ​ In some designs, the first transmission configuration is associated with a first comb size, and the second transmission configuration is associated with a second comb size that is different than the first comb size. In some designs, the second comb size is smaller than the first comb size. In some designs, the first comb size can be set relatively large (e.g., comb-12 or comb-24) because the uncertainty in time domain will be relatively small, so the aliasing introduced by a large comb size will not be an issue.

[0235] Referring to ​ In some designs, the first transmission configuration is associated with a first number of repetitions over consecutive time domain resources, and the second transmission configuration is associated with a second number of repetitions over consecutive time domain resources, the second number of repetitions being different than the first number.

[0236] Reference ​ In some designs, the second base station may perform one or more measurements on the reference radar signal. In some designs, the second base station may then transmit a request to the radar controller to update a first transmission configuration, a second transmission configuration, or both (e.g., based on measurements of the reference radar signal). The radar controller may then determine whether the requested update should be implemented. For example, if the second base station can sense a change in the power or SINR of the reference radar signal (e.g., due to some type of interference), the second base station may request, recommend, or require updates to the time-domain and / or frequency-domain resources associated with the reference radar signal.

[0237] ​ The respective implementations according to one aspect of this disclosure have been explained. ​ The communication system 2400, comprising processes 2100-2300, includes base stations 2405, 2410, and 2415 communicating with a radar controller 2420. The radar controller 2420 transmits first and second transmission configurations for a first reference radar signal and (e.g., for tracking target 2425) a first set of target radar signals to base stations 2405 and 2410 via communication links 2426 and 2427, respectively, and also transmits first and second transmission configurations for a second reference radar signal and (e.g., for tracking target 2430) a second set of target radar signals to base stations 2410 and 2415 via communication links 2427 and 2428, respectively. Base station 2410 transmits the first reference radar signal to base station 2405 via a first link 2435 (e.g., LOS), and transmits a set of the first set of target radar signals to base station 2405 via second links 2440-2445 (e.g., NLOS). Base station 2410 transmits a second reference radar signal to base station 2415 via a third link 2450 (e.g., LOS), and transmits a set of first target radar signals to base station 2415 via a fourth link 2455-2460 (e.g., NLOS). The first and second sets of target radar signals are also transmitted on other paths (or beams), as indicated by the dashed arrows.

[0238] In the detailed description above, various specific features are grouped together in examples. This manner of disclosure should not be treated in a way different from the way each individual example is treated. That is, the aspects of each example are not to be read out of the context of that example even if the aspects are referred to in a different example clause. The various aspects of the disclosure, therefore, can include fewer than all the features of an individual example disclosed. Thus, the appended claims are hereby expressly incorporated into this description, with each claim acting as a separate example. Although each dependent clause can refer in the clauses to a particular combination of features of one of the other clauses, the aspect(s) of the dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include combinations of the dependent clause aspect(s) with the subject matter of any other dependent or independent clause, or combinations of aspects with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations unless it is explicitly stated or can be readily inferred that a particular combination is not intended (e.g., contradictory aspects such as defining an element as both an insulator and a conductor). Moreover, it is also intended that aspects of a clause can be included in any other independent clause even if the clause is not directly dependent on the independent clause.

[0239] Implementation examples are described in the following numbered clauses:

[0240] Clause 1. A method of operating a radar controller, comprising: determining a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; determining a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmitting the first transmission configuration to the first base station and the second base station; and transmitting the second transmission configuration to the first base station and the second base station.

[0241] Clause 2. The method of clause 1, wherein the first transmission configuration and the second transmission configuration are different in subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0242] Clause 3. The method of any of clauses 1-2, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0243] Clause 4. The method of any of clauses 1-3, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0244] Clause 5. The method of any of clauses 1-4, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a time period.

[0245] Clause 6. The method of clause 5, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0246] Clause 7. The method of clause 6, further comprising: receiving an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0247] Clause 8. The method of any of clauses 1-7, wherein the first transmission configuration is associated with a shorter duration per instance of the reference radar signal than a second transmission configuration per instance of the target radar signal.

[0248] Clause 9. The method of any of clauses 1-8, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0249] Clause 10. The method of any of clauses 1-9, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0250] Clause 11. The method of any of clauses 1-10, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0251] Clause 12. The method of clause 11, wherein the second comb size is smaller than the first comb size.

[0252] Clause 13. The method of any of clauses 1-12, wherein the first transmission configuration is associated with a first number of repetitions over consecutive time domain resources, and wherein the second transmission configuration is associated with a second number of repetitions over the consecutive time domain resources, the second number of repetitions being different than the first number.

[0253] Clause 14. The method of any of clauses 1 to 13, further comprising: receiving, from the second base station, a request to update the first transmission configuration, the second transmission configuration, or both.

[0254] Clause 15. The method of any of clauses 1 to 14, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0255] Clause 16. A method of operating a first base station, comprising: receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmitting, to the second base station, the reference radar signal on the first link in accordance with the first transmission configuration; and transmitting, to the second base station, the at least one target radar signal on the at least one second link in accordance with the second transmission configuration.

[0256] Clause 17. The method of clause 16, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0257] Clause 18. The method of any of clauses 16 to 17, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0258] Clause 19. The method of any of clauses 16 to 18, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0259] Clause 20. The method of any of clauses 16 to 19, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0260] Clause 21. The method of clause 20, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0261] Clause 22. The method of Clause 21 further includes: transmitting an indication of the degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with periodicity based on the indication.

[0262] Clause 23. The method of any of Clauses 16 to 22, wherein the first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance.

[0263] Clause 24. The method of any of Clauses 16 to 23, wherein the first transmission configuration is associated with one or more target geographic areas including the first base station, or wherein the first transmission configuration is associated with one or more TRPs including at least one Transmitting and Receiving Point (TRP) including the first base station, or a combination thereof.

[0264] Clause 25. The method of any of Clauses 13 to 24, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0265] Clause 26. The method of any of Clauses 16 to 25, wherein the first transmission configuration is associated with a first comb tooth size, and wherein the second transmission configuration is associated with a second comb tooth size, the second comb tooth size being different from the first comb tooth size.

[0266] Clause 27. The method of Clause 26, wherein the size of the second comb tooth is smaller than the size of the first comb tooth.

[0267] Clause 28. The method of any of Clauses 16 to 27, wherein the reference radar signal is transmitted over a coherent time-domain resource with a first number of repetitions, and wherein the at least one target radar signal is transmitted over a coherent time-domain resource with a second number of repetitions, the second number of repetitions being different from the first number.

[0268] Clause 29. The method of any of Clauses 16 to 28, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0269] Clause 30. A method of operating a second base station, comprising: receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; receiving the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and receiving the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0270] Clause 31. The method of clause 30, wherein the first transmission configuration and the second transmission configuration are different in subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0271] Clause 32. The method of any of clauses 30-31, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0272] Clause 33. The method of any of clauses 30-32, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0273] Clause 34. The method of any of clauses 30-33, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0274] Clause 35. The method of clause 34, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0275] Clause 36. The method of clause 35, further comprising transmitting an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0276] Clause 37. The method of any of clauses 30-36, wherein the first transmission configuration is associated with a shorter duration per reference radar signal instance than the second transmission configuration per target radar signal instance.

[0277] Clause 38. The method of any of clauses 30 to 37, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0278] Clause 39. The method of any of clauses 30 to 38, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0279] Clause 40. The method of any of clauses 30 to 39, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0280] Clause 41. The method of clause 40, wherein the second comb size is smaller than the first comb size.

[0281] Clause 42. The method of any of clauses 30 to 41, wherein the reference radar signal is transmitted with a first number of repetitions over consecutive time domain resources, and wherein the at least one target radar signal is transmitted with a second number of repetitions over consecutive time domain resources, the second number of repetitions being different than the first number.

[0282] Clause 43. The method of any of clauses 30 to 42, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0283] Clause 44. The method of any of clauses 30 to 43, further comprising: performing one or more measurements on the reference radar signal; and transmitting, to the radar controller, a request to update the first transmission configuration, the second transmission configuration, or both, in response to the one or more measurements.

[0284] Clause 45. A radar controller, comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: determine a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; determine a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration different from the second transmission configuration; transmit, via the at least one transceiver, the first transmission configuration to the first base station and the second base station; and transmit, via the at least one transceiver, the second transmission configuration to the first base station and the second base station.

[0285] Clause 46. The radar controller of Clause 45, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0286] Clause 47. The radar controller of any of Clauses 45-46, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0287] Clause 48. The radar controller of any of Clauses 45-47, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0288] Clause 49. The radar controller of any of Clauses 45-48, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a time period.

[0289] Clause 50. The radar controller of Clause 49, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0290] Clause 51. The radar controller of Clause 50, wherein the at least one processor is further configured to: receive, via the at least one transceiver, an indication of a degree of time domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0291] Clause 52. A radar controller as described in any of Clauses 45 to 51, wherein the first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance.

[0292] Clause 53. A radar controller as described in any of Clauses 45 to 52, wherein the first transmission configuration is associated with one or more target geographic areas including the first base station, or wherein the first transmission configuration is associated with one or more TRPs including at least one transmit-receive point (TRP) including the first base station, or a combination thereof.

[0293] Clause 54. A radar controller as described in any of Clauses 45 to 53, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0294] Clause 55. A radar controller as described in any of Clauses 45 to 54, wherein a first transmission configuration is associated with a first comb tooth size, and wherein a second transmission configuration is associated with a second comb tooth size, the second comb tooth size being different from the first comb tooth size.

[0295] Clause 56. A radar controller as described in Clause 55, wherein the size of the second comb tooth is smaller than the size of the first comb tooth.

[0296] Clause 57. A radar controller as described in any of Clauses 45 to 56, wherein a first transmission configuration is associated with a first repetition number on a coherent time-domain resource, and wherein a second transmission configuration is associated with a second repetition number on a coherent time-domain resource, the second repetition number being different from the first number.

[0297] Clause 58. A radar controller as described in any of Clauses 45 to 57, wherein the at least one processor is further configured to receive, via the at least one transceiver, a request from the second base station to update the first transmission configuration, the second transmission configuration, or both.

[0298] Clause 59. A radar controller as described in any of Clauses 45 to 58, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0299] Clause 60. A radar controller as described in any of Clauses 48 to 59, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0300] Clause 61. A first base station, comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: receive, via the at least one transceiver, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; receive, via the at least one transceiver, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmit, via the at least one transceiver, the reference radar signal to the second base station on the first link in accordance with the first transmission configuration; and transmit, via the at least one transceiver, the at least one target radar signal to the second base station on the at least one second link in accordance with the second transmission configuration.

[0301] Clause 62. The first base station of Clause 61, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0302] Clause 63. The first base station of any of Clauses 61 to 62, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0303] Clause 64. The first base station of any of Clauses 61 to 63, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0304] Clause 65. The first base station of any of Clauses 61 to 64, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0305] Clause 66. The first base station of Clause 65, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0306] Clause 67. The first base station of Clause 66, wherein the at least one processor is further configured to transmit, via the at least one transceiver, an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0307] Clause 68. The first base station of any of Clauses 61-67, wherein the first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance.

[0308] Clause 69. The first base station of any of Clauses 61-68, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0309] Clause 70. The first base station of any of Clauses 60-69, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size that is different from the first comb size.

[0310] Clause 71. The first base station of Clause 70, wherein the second comb size is smaller than the first comb size.

[0311] Clause 72. The first base station of any of Clauses 60-71, wherein the reference radar signal is transmitted with a first number of repetitions over consecutive time-domain resources, and wherein the at least one target radar signal is transmitted with a second number of repetitions over consecutive time-domain resources, the second number of repetitions being different from the first number.

[0312] Clause 73. The first base station of any of Clauses 60-72, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0313] Clause 74. A second base station, comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: receive, via the at least one transceiver, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; receive, via the at least one transceiver, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; receive, via the at least one transceiver, the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and receive, via the at least one transceiver, the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0314] Clause 75. The second base station of Clause 74, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0315] Clause 76. The second base station of any of Clauses 74 to 75, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0316] Clause 77. The second base station of any of Clauses 74 to 76, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0317] Clause 78. The second base station of any of Clauses 74 to 77, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a time period.

[0318] Clause 79. The second base station of Clause 78, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0319] Clause 80. The second base station of Clause 79, wherein the at least one processor is further configured to transmit, via the at least one transceiver, an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0320] Clause 81. The second base station of any of Clauses 74-80, wherein the first transmission configuration is associated with a shorter duration for each reference radar signal instance than the second transmission configuration for each target radar signal instance.

[0321] Clause 82. The second base station of any of Clauses 74-81, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0322] Clause 83. The second base station of any of Clauses 74-82, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0323] Clause 84. The second base station of any of Clauses 74-83, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0324] Clause 85. The second base station of Clause 84, wherein the second comb size is smaller than the first comb size.

[0325] Clause 86. The second base station of any of Clauses 74-85, wherein the reference radar signal is transmitted a first number of repetitions over consecutive time-domain resources, and wherein the at least one target radar signal is transmitted a second number of repetitions over consecutive time-domain resources, the second number of repetitions being different than the first number.

[0326] Clause 87. The second base station of any of Clauses 74-86, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0327] Clause 88. The second base station of any of Clauses 74-87, wherein the at least one processor is further configured to perform one or more measurements on the reference radar signal; and transmit, via the at least one transceiver, a request to update the first transmission configuration, the second transmission configuration, or both, to the radar controller in response to the one or more measurements.

[0328] Clause 89. A radar controller comprising: means for determining a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; means for determining a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for transmitting the first transmission configuration to the first base station and the second base station; and means for transmitting the second transmission configuration to the first base station and the second base station.

[0329] Clause 90. The radar controller of Clause 89, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0330] Clause 91. The radar controller of any of Clauses 89-90, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0331] Clause 92. The radar controller of any of Clauses 89-91, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0332] Clause 93. The radar controller of any of Clauses 89-92, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0333] Clause 94. The radar controller of Clause 93, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0334] Clause 95. The radar controller of Clause 94, further comprising: means for receiving an indication of a degree of time domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0335] Clause 96. The radar controller of any of clauses 89 to 95, wherein the first transmission configuration is associated with a shorter duration of each reference radar signal instance compared to the second transmission configuration of each target radar signal instance.

[0336] Clause 97. The radar controller of any of clauses 89 to 96, wherein the first transmission configuration is associated with one or more target geographic areas comprising the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) comprising at least one TRP of the first base station, or a combination thereof.

[0337] Clause 98. The radar controller of any of clauses 89 to 97, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0338] Clause 99. The radar controller of any of clauses 89 to 98, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0339] Clause 100. The radar controller of clause 99, wherein the second comb size is smaller than the first comb size.

[0340] Clause 101. The radar controller of any of clauses 89 to 100, wherein the first transmission configuration is associated with a first number of repetitions over consecutive time domain resources, and wherein the second transmission configuration is associated with a second number of repetitions over the consecutive time domain resources, the second number of repetitions being different than the first number.

[0341] Clause 102. The radar controller of any of clauses 89 to 101, further comprising: means for receiving a request from the second base station to update the first transmission configuration, the second transmission configuration, or both.

[0342] Clause 103. The radar controller of any of clauses 89 to 102, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0343] Clause 104. The radar controller of any of clauses 92 to 103, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0344] Clause 105. A first base station, comprising: means for receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; means for receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for transmitting the reference radar signal to the second base station on the first link in accordance with the first transmission configuration; and means for transmitting the at least one target radar signal to the second base station on the at least one second link in accordance with the second transmission configuration.

[0345] Clause 106. The first base station of Clause 105, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0346] Clause 107. The first base station of any of Clauses 105 to 106, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0347] Clause 108. The first base station of any of Clauses 105 to 107, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0348] Clause 109. The first base station of any of Clauses 105 to 108, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a time period.

[0349] Clause 110. The first base station of Clause 109, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0350] Clause 111. The first base station of Clause 110, further comprising: means for transmitting an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0351] Clause 112. The first base station of any of clauses 105 to 111, wherein the first transmission configuration is associated with a shorter duration of each reference radar signal instance compared to the second transmission configuration of each target radar signal instance.

[0352] Clause 113. The first base station of any of clauses 105 to 112, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0353] Clause 114. The first base station of any of clauses 104 to 113, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size that is different from the first comb size.

[0354] Clause 115. The first base station of clause 114, wherein the second comb size is smaller than the first comb size.

[0355] Clause 116. The first base station of any of clauses 104 to 115, wherein the reference radar signal is transmitted with a first number of repetitions over consecutive time domain resources, and wherein the at least one target radar signal is transmitted with a second number of repetitions over the consecutive time domain resources, the second number of repetitions being different from the first number.

[0356] Clause 117. The first base station of any of clauses 104 to 116, wherein the first transmission configuration is associated with a default beam from the first base station to a second base station.

[0357] Clause 118. A second base station comprising: means for receiving, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; means for receiving, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; means for receiving the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and means for receiving the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0358] Clause 119. The second base station of clause 118, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0359] Clause 120. The second base station of any of clauses 118 to 119, wherein the first link corresponds to a line of sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0360] Clause 121. The second base station of any of clauses 118 to 120, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0361] Clause 122. The second base station of any of clauses 118 to 121, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a time period.

[0362] Clause 123. The second base station of clause 122, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0363] Clause 124. The second base station of clause 123, further comprising: means for transmitting an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0364] Clause 125. The second base station of any of clauses 118 to 124, wherein the first transmission configuration is associated with a shorter duration per reference radar signal instance than a second transmission configuration per target radar signal instance.

[0365] Clause 126. The second base station of any of clauses 118 to 125, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0366] Clause 127. The second base station of any of clauses 118 to 126, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0367] Clause 128. The second base station of any of clauses 118 to 127, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0368] Clause 129. The second base station of clause 128, wherein the second comb size is smaller than the first comb size.

[0369] Clause 130. The second base station of any of clauses 118 to 129, wherein the reference radar signal is transmitted with a first number of repetitions over consecutive time domain resources, and wherein the at least one target radar signal is transmitted with a second number of repetitions over consecutive time domain resources, the second number of repetitions being different than the first number.

[0370] Clause 131. The second base station of any of clauses 118 to 130, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0371] Clause 132. The second base station of any of clauses 118 to 131, further comprising: means for performing one or more measurements on the reference radar signal; and means for transmitting, to the radar controller, a request to update the first transmission configuration, the second transmission configuration, or both, in response to the one or more measurements.

[0372] Clause 133. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a radar controller, cause the radar controller to: determine a first transmission configuration for a reference radar signal on a first link from a first base station to a second base station; determine a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal being for sensing at least one target, the first transmission configuration being different than the second transmission configuration; transmit the first transmission configuration to the first base station and the second base station; and transmit the second transmission configuration to the first base station and the second base station.

[0373] Clause 134. The non-transitory computer-readable medium of clause 133, wherein the first transmission configuration and the second transmission configuration differ in subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0374] Clause 135. The non-transitory computer-readable medium of any of clauses 133 to 134, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0375] Clause 136. The non-transitory computer-readable medium of any of clauses 133 to 135, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0376] Clause 137. The non-transitory computer-readable medium of any of clauses 133 to 136, wherein the first transmission configuration configures fewer transmissions of the reference radar signal compared to the at least one target radar signal over a time period.

[0377] Clause 138. The non-transitory computer-readable medium of clause 137, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity compared to the at least one target radar signal.

[0378] Clause 139. The non-transitory computer-readable medium of clause 138, further comprising computer-executable instructions that, when executed by the radar controller, cause the radar controller to: receive an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0379] Clause 140. The non-transitory computer-readable medium of any of clauses 133 to 139, wherein the first transmission configuration is associated with a shorter duration per instance of the reference radar signal compared to a second transmission configuration per instance of the target radar signal.

[0380] Clause 141. The non-transitory computer-readable medium of any of clauses 133 to 140, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0381] Clause 142. The non-transitory computer-readable medium of any of clauses 133 to 141, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0382] Clause 143. The non-transitory computer-readable medium of any of clauses 133 to 142, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0383] Clause 144. The non-transitory computer-readable medium of clause 143, wherein the second comb size is smaller than the first comb size.

[0384] Clause 145. The non-transitory computer-readable medium of any of clauses 133 to 144, wherein the first transmission configuration is associated with a first number of repetitions over consecutive time domain resources, and wherein the second transmission configuration is associated with a second number of repetitions over consecutive time domain resources, the second number of repetitions being different than the first number.

[0385] Clause 146. The non-transitory computer-readable medium of any of clauses 133 to 145, further comprising computer-executable instructions that, when executed by the radar controller, cause the radar controller to: receive, from a second base station, a request to update the first transmission configuration, the second transmission configuration, or both.

[0386] Clause 147. The non-transitory computer-readable medium of any of clauses 133 to 146, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0387] Clause 148. The non-transitory computer-readable medium of any of clauses 136 to 147, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0388] Clause 149. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a first base station, cause the first base station to: receive, from a radar controller, a first transmission configuration for a reference radar signal on a first link from the first base station to a second base station; receive, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; transmit, to the second base station, the reference radar signal on the first link in accordance with the first transmission configuration; and transmit, to the second base station, the at least one target radar signal on the at least one second link in accordance with the second transmission configuration.

[0389] Clause 150. The non-transitory computer-readable medium of Clause 149, wherein the first transmission configuration and the second transmission configuration are different in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0390] Clause 151. The non-transitory computer-readable medium of any of Clauses 149 to 150, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0391] Clause 152. The non-transitory computer-readable medium of any of Clauses 149 to 151, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0392] Clause 153. The non-transitory computer-readable medium of any of Clauses 149 to 152, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0393] Clause 154. The non-transitory computer-readable medium of Clause 153, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0394] Clause 155. The non-transitory computer-readable medium of clause 154, further comprising computer-executable instructions that, when executed by the first base station, cause the first base station to: transmit an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0395] Clause 156. The non-transitory computer-readable medium of any of clauses 149-155, wherein the first transmission configuration is associated with a shorter duration per reference radar signal instance than the second transmission configuration per target radar signal instance.

[0396] Clause 157. The non-transitory computer-readable medium of any of clauses 149-156, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0397] Clause 158. The non-transitory computer-readable medium of any of clauses 148-157, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size that is different than the first comb size.

[0398] Clause 159. The non-transitory computer-readable medium of clause 158, wherein the second comb size is smaller than the first comb size.

[0399] Clause 160. The non-transitory computer-readable medium of any of clauses 148-159, wherein the reference radar signal is transmitted a first number of repetitions over consecutive time-domain resources, and wherein the at least one target radar signal is transmitted a second number of repetitions over consecutive time-domain resources, the second number of repetitions being different than the first number.

[0400] Clause 161. The non-transitory computer-readable medium of any of clauses 148-160, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0401] Clause 162. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a second base station, cause the second base station to: receive, from a radar controller, a first transmission configuration for a reference radar signal on a first link from a first base station to the second base station; receive, from the radar controller, a second transmission configuration for at least one target radar signal on at least one second link from the first base station to the second base station, the at least one target radar signal for sensing at least one target, the first transmission configuration being different from the second transmission configuration; receive the reference radar signal from the first base station on the first link in accordance with the first transmission configuration; and receive the at least one target radar signal from the first base station on the at least one second link in accordance with the second transmission configuration.

[0402] Clause 163. The non-transitory computer-readable medium of clause 162, wherein the first transmission configuration and the second transmission configuration differ in subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof.

[0403] Clause 164. The non-transitory computer-readable medium of any of clauses 162 to 163, wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station, and wherein the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first base station to the second base station.

[0404] Clause 165. The non-transitory computer-readable medium of any of clauses 162 to 164, wherein the first transmission configuration is used for the reference radar signal regardless of whether the first link corresponds to a LOS link, a direct link, or an earliest time of arrival (EToA) link from the first base station to the second base station.

[0405] Clause 166. The non-transitory computer-readable medium of any of clauses 162 to 165, wherein the first transmission configuration configures fewer transmissions of the reference radar signal than the at least one target radar signal over a period of time.

[0406] Clause 167. The non-transitory computer-readable medium of clause 166, wherein the first transmission configuration configures periodic transmissions of the reference radar signal and the at least one target radar signal, and wherein the reference radar signal is associated with a longer periodicity than the at least one target radar signal.

[0407] Clause 168. The non-transitory computer-readable medium of clause 167, further comprising computer-executable instructions that, when executed by the second base station, cause the second base station to: transmit an indication of a degree of time-domain drift between the first base station and the second base station, wherein the first transmission configuration is associated with a periodicity based on the indication.

[0408] Clause 169. The non-transitory computer-readable medium of any of clauses 162 to 168, wherein the first transmission configuration is associated with a shorter duration per reference radar signal instance than the second transmission configuration per target radar signal instance.

[0409] Clause 170. The non-transitory computer-readable medium of any of clauses 162 to 169, wherein the first transmission configuration is associated with one or more target geographic areas that include the first base station, or wherein the first transmission configuration is associated with one or more transmission reception points (TRPs) that include at least one TRP of the first base station, or a combination thereof.

[0410] Clause 171. The non-transitory computer-readable medium of any of clauses 162 to 170, wherein the reference radar signal corresponds to a synchronization signal block (SSB), a primary synchronization signal, a secondary synchronization signal, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), or a tracking reference signal (TRS), or a channel state information reference signal (CSI-RS).

[0411] Clause 172. The non-transitory computer-readable medium of any of clauses 162 to 171, wherein the first transmission configuration is associated with a first comb size, and wherein the second transmission configuration is associated with a second comb size, the second comb size being different than the first comb size.

[0412] Clause 173. The non-transitory computer-readable medium of clause 172, wherein the second comb size is smaller than the first comb size.

[0413] Clause 174. The non-transitory computer-readable medium of any of clauses 162 to 173, wherein the reference radar signal is transmitted a first number of repetitions over consecutive time-domain resources, and wherein the at least one target radar signal is transmitted a second number of repetitions over consecutive time-domain resources, the second number of repetitions being different than the first number.

[0414] Clause 175. The non-transitory computer-readable medium of any of clauses 162 to 174, wherein the first transmission configuration is associated with a default beam from the first base station to the second base station.

[0415] Clause 176. The non-transitory computer-readable medium of any of clauses 162 to 175, further comprising computer-executable instructions that, when executed by the second base station, cause the second base station to: perform one or more measurements on the reference radar signal; and transmit, to the radar controller, a request to update the first transmission configuration, the second transmission configuration, or both, in response to the one or more measurements.

[0416] Those skilled in the art will appreciate that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0417] Further, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0418] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or performed with a general purpose processor, a DSP, an ASIC, a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0419] The methods, sequences, and / or algorithms described in connection with the aspects disclosed herein can be embodied directly in hardware, in software with associated firmware, or in a combination of the two. Software modules can reside in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal (e.g., an UE). In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

[0420] In one or more exemplary aspects, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0421] While the forgoing disclosure shows illustrative aspects of the present disclosure, it should be noted that various changes and modifications could be made without departing from the scope of the present disclosure as defined in the appended claims. The functions, steps and / or actions of the methods claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although elements of the present disclosure can be described or claimed in particular combinations, each combination should be considered as separate and discrete embodiments of the present disclosure, unless otherwise explicitly stated.

Claims

1. A method for operating a radar controller, comprising: Determine a first transmission configuration for a reference radar signal on a first link from a first network node to a second network node; A second transmission configuration is determined for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, the first transmission configuration being different from the second transmission configuration; The first transmission configuration is transmitted to the first network node and the second network node, wherein the first transmission configuration is transmitted less than the reference radar signal is transmitted within a time period compared to the at least one target radar signal configuration; as well as The second transmission configuration is transmitted to the first network node and the second network node.

2. The method as described in claim 1, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

3. The method as described in claim 1, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

4. The method as described in claim 1, The reference radar signal mentioned therein corresponds to the Synchronization Signal Block (SSB), Primary Synchronization Signal, Secondary Synchronization Signal, Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH), or Tracking Reference Signal (TRS), or Channel State Information Reference Signal (CSI-RS), or Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The first transmission configuration is associated with a first number of repetitions on a coherent time-domain resource, and the second transmission configuration is associated with a second number of repetitions on a coherent time-domain resource, the second number of repetitions being different from the first number, or Any combination thereof.

5. The method of claim 1, further comprising: Receive a request from the second network node to update the first transport configuration, the second transport configuration, or both.

6. The method of claim 1, wherein the first transmission configuration is associated with a default beam from the first network node to the second network node.

7. A method for operating a first network node, comprising: Receive a first transmission configuration from the radar controller for a reference radar signal on a first link from the first network node to the second network node; The radar controller receives a second transmission configuration for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, and the first transmission configuration differs from the second transmission configuration. The reference radar signal is transmitted to the second network node on the first link according to the first transmission configuration, wherein the first transmission configuration transmits the reference radar signal less frequently than the at least one target radar signal configuration within a time period; as well as According to the second transmission configuration, the at least one target radar signal is transmitted to the second network node on the at least one second link.

8. The method as described in claim 7, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

9. The method as described in claim 7, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

10. The method as described in claim 7, Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The reference radar signal is transmitted with a first number of repetitions over a coherent time-domain resource, and the at least one target radar signal is transmitted with a second number of repetitions over a coherent time-domain resource, the second number of repetitions being different from the first number, or The first transmission configuration is associated with the default beam from the first network node to the second network node, or Any combination thereof.

11. A method for operating a second network node, comprising: Receive a first transmission configuration from the radar controller for a reference radar signal on a first link from the first network node to the second network node; The radar controller receives a second transmission configuration for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, and the first transmission configuration differs from the second transmission configuration. The reference radar signal is received from the first network node on the first link according to the first transmission configuration, wherein the first transmission configuration transmits the reference radar signal less than the at least one target radar signal configuration within a time period; as well as According to the second transmission configuration, the at least one target radar signal is received from the first network node on at least one second link.

12. The method as described in claim 11, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

13. The method as described in claim 11, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

14. The method as described in claim 11, The reference radar signal mentioned therein corresponds to the Synchronization Signal Block (SSB), Primary Synchronization Signal, Secondary Synchronization Signal, Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH), or Tracking Reference Signal (TRS), or Channel State Information Reference Signal (CSI-RS), or Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The reference radar signal is transmitted with a first number of repetitions over a coherent time-domain resource, and the at least one target radar signal is transmitted with a second number of repetitions over a coherent time-domain resource, the second number of repetitions being different from the first number, or The first transmission configuration is associated with the default beam from the first network node to the second network node, or Any combination thereof.

15. The method of claim 11, further comprising: Perform one or more measurements on the reference radar signal; as well as In response to one or more measurements, a request is sent to the radar controller to update the first transmission configuration, the second transmission configuration, or both.

16. A radar controller, comprising: Memory; At least one transceiver; as well as At least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Determine a first transmission configuration for a reference radar signal on a first link from a first network node to a second network node; A second transmission configuration is determined for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, the first transmission configuration being different from the second transmission configuration; The first transmission configuration is transmitted to the first network node and the second network node via the at least one transceiver, wherein the first transmission configuration is transmitted less than the reference radar signal in a time period compared to the at least one target radar signal configuration; as well as The second transmission configuration is transmitted to the first network node and the second network node via the at least one transceiver.

17. The radar controller as described in claim 16, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

18. The radar controller as described in claim 16, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

19. The radar controller as described in claim 16, The reference radar signal mentioned therein corresponds to the Synchronization Signal Block (SSB), Primary Synchronization Signal, Secondary Synchronization Signal, Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH), or Tracking Reference Signal (TRS), or Channel State Information Reference Signal (CSI-RS), or Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The first transmission configuration is associated with a first number of repetitions on a coherent time-domain resource, and the second transmission configuration is associated with a second number of repetitions on a coherent time-domain resource, the second number of repetitions being different from the first number, or Any combination thereof.

20. The radar controller of claim 16, wherein the at least one processor is further configured to: The request to update the first transmission configuration, the second transmission configuration, or both can be received from the second network node via the at least one transceiver.

21. The radar controller of claim 16, wherein the first transmission configuration is associated with a default beam from the first network node to the second network node.

22. A first network node, comprising: Memory; At least one transceiver; as well as At least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Receive a first transmission configuration from the radar controller via the at least one transceiver for a reference radar signal on a first link from the first network node to the second network node; A second transmission configuration for receiving, via the at least one transceiver, from the radar controller for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, the first transmission configuration being different from the second transmission configuration; The reference radar signal is transmitted to the second network node via the at least one transceiver on the first link according to the first transmission configuration, wherein the first transmission configuration transmits the reference radar signal less per time period compared to the at least one target radar signal configuration. as well as According to the second transmission configuration, the at least one target radar signal is transmitted to the second network node via the at least one transceiver over the at least one second link.

23. The first network node as described in claim 22, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

24. The first network node as described in claim 22, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

25. The first network node as described in claim 22, Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The reference radar signal is transmitted with a first number of repetitions over a coherent time-domain resource, and the at least one target radar signal is transmitted with a second number of repetitions over a coherent time-domain resource, the second number of repetitions being different from the first number, or The first transmission configuration is associated with the default beam from the first network node to the second network node, or Any combination thereof.

26. A second network node, comprising: Memory; At least one transceiver; as well as At least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Receive a first transmission configuration from the radar controller via the at least one transceiver for a reference radar signal on a first link from the first network node to the second network node; A second transmission configuration for receiving, via the at least one transceiver, from the radar controller for at least one target radar signal on at least one second link from the first network node to the second network node, the at least one target radar signal being used to sense at least one target, the first transmission configuration being different from the second transmission configuration; The reference radar signal is received from the first network node on the first link via the at least one transceiver according to the first transmission configuration, wherein the first transmission configuration transmits the reference radar signal less per time period compared to the at least one target radar signal configuration. as well as According to the second transmission configuration, the at least one target radar signal is received from the first network node via the at least one transceiver on the at least one second link.

27. The second network node as described in claim 26, The first transmission configuration and the second transmission configuration differ in terms of subcarrier spacing (SCS), cyclic prefix (CP) type, sequence type, number of ports, bandwidth or frequency band, frequency domain reference point, or a combination thereof. Wherein the first link corresponds to a line-of-sight (LOS) link, a direct link, or an earliest time-of-arrival (EToA) link from the first network node to the second network node, and the at least one second link corresponds to at least one non-LOS (NLOS) link, an indirect link, or a non-EToA link from the first network node to the second network node, or The first transmission configuration is used for the reference radar signal, regardless of whether the first link corresponds to a LOS link, a direct link, or an EToA link from the first network node to the second network node. Any combination thereof.

28. The second network node as described in claim 26, The first transmission configuration is associated with a shorter duration for each reference radar signal instance compared to the second transmission configuration for each target radar signal instance, or Wherein the first transmission configuration is associated with one or more target geographic regions including the first network node, or The first transmission configuration is associated with one or more Transmitter-Receiver Points (TRPs) including at least one Transmitter-Receiver Point (TRP) of the first network node, or Any combination thereof.

29. The second network node as described in claim 26, The reference radar signal mentioned therein corresponds to the Synchronization Signal Block (SSB), Primary Synchronization Signal, Secondary Synchronization Signal, Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH), or Tracking Reference Signal (TRS), or Channel State Information Reference Signal (CSI-RS), or Wherein the first transmission configuration is associated with the first comb tooth size, and the second transmission configuration is associated with the second comb tooth size, the second comb tooth size being different from the first comb tooth size, or The reference radar signal is transmitted with a first number of repetitions over a coherent time-domain resource, and the at least one target radar signal is transmitted with a second number of repetitions over a coherent time-domain resource, the second number of repetitions being different from the first number, or The first transmission configuration is associated with the default beam from the first network node to the second network node, or Any combination thereof.

30. The second network node of claim 26, wherein the at least one processor is further configured to: Perform one or more measurements on the reference radar signal; and In response to one or more measurements, a request to update the first transmission configuration, the second transmission configuration, or both is transmitted to the radar controller via the at least one transceiver.

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