Co-Existence Operations Involving a Radar-Enabled User Equipment and Radio Network Nodes

A radar-enabled wireless communication device (12) is configured to communicate with a wireless communication network (10) and performs radar transmissions using a same or overlapping millimeter wave (mmW) frequency range, determine whether there are any neighboring wireless communication devices (32) that are vulnerable to interference from the radar transmissions and, if so, adapt radar transmissions in the affected radar beam directions or transmit assistance information enabling the vulnerable devices (32) to mitigate or avoid the interference. In a particular example, the wireless communication device (12) performs radar transmissions during a Downlink (DL) phase of the wireless communication network (10), such that the vulnerability determinations are with respect to DL interference at the neighboring wireless communication devices (32). Vulnerability determinations may be performed with or without support of the wireless communication network (10) and may be updated responsive to detecting changed conditions.

TECHNICAL FIELD

The present disclosure relates to radar-enabled user equipments and, specifically, to co-existence operations involving radar-enabled user equipments.

BACKGROUND

Adopting millimeter wave (mmW) frequency ranges for wireless communication networks allows using more antennas with smaller distances, which provides various advantages, including the ability to perform beamforming at the User Equipments (UEs). As a result, device manufactures are equipping UEs, such as those configured for use with communication networks based on Fifth Generation (5G) New Radio (NR) specifications, with antenna panels. Antenna panels can be installed in different locations within a UE and face different directions. In addition, each antenna panel generates different beams depending on the spatial filtering used. Panel orientation changes when the orientation of the UE changes.

The same or similar frequency ranges may be used for radar probing, wherein one or more UEs use radar transmissions for sensing their surrounding environments. As one example, radar probing facilitates autonomous navigation by mobile robots or Autonomous Guided Vehicles (AGVs). As another example, radar probing allows UEs to detect walls or other obstructions proximate to their current position, which may interfere with communications or other operations.

UEs performing radar probing in the same or overlapping mmW frequency range(s) used by wireless communication networks raises the potential for significant interference between radar transmissions and communication transmissions. Such UEs are referred to as “radar-enabled UEs”, to denote a wireless communication device that is configured for accessing and using a wireless communication network and further configured to perform radar probing of its surrounding environment.

As used herein, the term “radar” refers to a type of sensing in which one or more radiofrequency signals are transmitted (by one or more transmitters) into a sensing environment, and reflections of those signals received (by one or more receivers). An analysis of the received reflection signals provides information about objects that the signals reflected off of in the sensing environment.

Regarding the operation of radar-enabled UEs, U.S. Pub. 2019/0293781 A1 proposes using separate (orthogonal) resources of a radio channel for transmitting communication signals versus radar signals. While U.S. Pub. 2017/0318470 A1 also considers radar, it more broadly addresses different networks operating in the same shared spectrum, rather than the challenges associated with having radar-enabled UEs operating in a wireless communication network. Similarly, U.S. Pat. 10,439,743 B2 addresses radar in the context of wireless communication systems coexisting with, for example, automotive radar systems.

SUMMARY

A radar-enabled wireless communication device is configured to communicate with a wireless communication network and performs radar transmissions using a same or overlapping millimeter wave (mmW) frequency range, determine whether there are any neighboring wireless communication devices that are vulnerable to interference from the radar transmissions and, if so, adapt radar transmissions in the affected radar beam directions or transmit assistance information enabling the vulnerable devices to mitigate or avoid the interference. In a particular example, the wireless communication device performs radar transmissions during a Downlink (DL) phase of the wireless communication network, such that the vulnerability determinations are with respect to DL interference at the neighboring wireless communication devices. Vulnerability determinations may be performed with or without support of the wireless communication network and may be updated responsive to a change in conditions.

In an example embodiment, a wireless communication device includes communication circuitry that is configured to communicate with a wireless communication network and perform radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The device further includes processing circuitry that is operatively associated with the communication circuitry and configured to determine, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network. The processing circuitry is further configured to identify any such radar beam directions as being an interfering radar beam direction and, responsive to identifying one or more interfering radar beam directions, perform DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring wireless communication devices.

In another embodiment, a wireless communication device includes communication circuitry that is configured to communicate with a wireless communication network and perform radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The device further includes a determining module that is configured to determine, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network. Further, the device includes an identifying module that is configured to identify any such radar beam directions as being an interfering radar beam direction. A mitigating module of the device is configured to perform, in response to the identification of one or more interfering radar beam directions, DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring wireless communication devices.

Another embodiment comprises method of operation by a wireless communication device that communicates with a wireless communication network and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The method includes determining, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network. If so, the method includes identifying the radar beam direction as being an interfering radar beam direction and, responsive to identifying one or more interfering radar beam directions, performing DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring wireless communication devices.

Another embodiment comprises a radio network node that is configured for operation in a wireless communication network. The radio network node includes communication circuitry and processing circuitry. The processing circuitry is configured to receive, via the communication circuitry, feedback from one or more other wireless communication devices neighboring a wireless communication device that communicates with the wireless communication network and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other wireless communication device comprises measurements made by the other wireless communication device on reference signal transmissions by the wireless communication device, and the processing circuitry is configured to send, via the communication circuitry, DL signaling for the wireless communication device. The DL signaling is based on the feedback from the one or more other wireless communication devices and thereby enables the wireless communication device to determine, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network.

Yet another embodiment comprises a radio network node that is configured for operation in a wireless communication network. The radio network node includes a receiving module that is configured to receive feedback from one or more other wireless communication devices neighboring a wireless communication device that communicates with the wireless communication network and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other wireless communication device comprises measurements made by the other wireless communication device on reference signal transmissions by the wireless communication device, and the radio network node includes a sending module that is configured to send DL signaling for the wireless communication device. The DL signaling is based on the feedback from the one or more other wireless communication devices and thereby enables the wireless communication device to determine, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network.

Another embodiment comprises a method performed by a radio network node of a wireless communication network. The method includes receiving feedback from one or more other wireless communication devices neighboring a wireless communication device that communicates with the wireless communication network and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other wireless communication device comprises measurements made by the other wireless communication device on reference signal transmissions by the wireless communication device, and the method further includes sending DL signaling for the wireless communication device, the feedback based on the feedback from the one or more other wireless communication devices and thereby enabling the wireless communication device to determine, for each radar beam direction among a plurality of radar beam directions relative to a current orientation and position of the wireless communication device, whether there are any neighboring wireless communication devices vulnerable to interference from radar transmissions by the wireless communication device with respect to receiving DL communication signals from the wireless communication network.

DETAILED DESCRIPTION

FIG.1illustrates an example wireless communication network10that operates as an “access network” for a wireless communication device12, e.g., by communicatively coupling the device12to one or more external networks14that provide access to one or more external systems or devices16. Non-limiting examples of communication services provided by the network10include voice services and data services and in at least one embodiment the network10is configured according to Technical Specifications (TSs) released by the Third Generation Partnership Project (3GPP).

In its example form, the network10includes a Radio Access Network (RAN)20that includes a number of radio network nodes22. The nodes22may be understood as access points, base stations, or other equipment that is configured to provide the air interface(s) / radio link(s) used to wirelessly connect with the communication device12. Further, while individual nodes are not illustrated, a Core Network (CN)24of the network10includes nodes implementing various network functions needed to authenticate and manage the device12and to route data to/from the device12with respect to the external network(s)14and the external systems/devices16.

At any given time and within any given coverage area of the RAN20, the network10may support a potentially large number of wireless communication devices, also referred to as User Equipments or UEs. The devices may be of varying types and may use different communication services, e.g., some may be smartphones or other personal computing devices, while others are Machine Type Communication (MTC) or Internet-of-Things (IoT) devices, including stationary or embedded devices.FIG.1suggests various ones of these scenarios by illustrating other wireless communications devices32-1and32-2, in addition to illustrating the device12. At any given time, there may be none, one, or multiple other wireless communication devices32that neighbor the device12. Here, “neighbor” means proximate to or in the surrounding vicinity of the device12, e.g., in a radio-range sense.

While the devices32may be of the same type as the device12, the different reference numbers provide clarity for discussing operations of the device12as a radar-enabled device, with respect to the potential for its radar transmissions to interfere with the reception of network communication signals-Downlink (DL) signals-at one or more other wireless communication devices32. For example, a radar transmission by the device12that is coincident with DL transmission targeting another device32may interfere with reception of the DL transmission at the other device32. In this respect, the device12is configured to perform radar transmissions along one or more radar beam directions30, with example directions30-1through30-5shown by way of example. Note that for the reference number30and any other reference numbers shown with suffixing, the corresponding discussion uses suffixed reference numbers only when needed for clarity.

Later diagrams elaborate details of the device12but for now consider that the device12in one or more embodiments has transmit beamforming capability and has one or more antennas or sets of antenna elements that allow it to perform beamforming in a plurality of directions that are relative to the orientation of the device12. In an example case, the device12uses predefined beam shapes/directions, where such directions may be predefined with respect to the device12but, in an absolute sense depend on the current orientation of the device12.

FIG.1suggests that radar transmissions by the device12in one or more radar beam directions30may interfere with DL reception operations at respective other devices32, in dependence on a number of factors having complex interrelations. Example factors include the position and/or orientation of the device12relative to the other device(s)32, the position and/or orientation of each other device32in relation to the device12and/or its serving radio network node22in the network10, the transmission power(s) used by the device12for its radar transmissions, the path loss between the device12and respective ones of the other devices32, the frequencies of the communication signals and radar signals, etc.

In a particular example, the network10operates according to a Time Division Duplexing (TDD) arrangement that includes a DL phase wherein the network10performs DL operations and an UL phase wherein the network10performs UL operations, and methods and apparatuses contemplated herein avoid or reduce radar interference by the device12with respect to DL reception at one or more other devices32during the DL phase of operations. For example, in conjunction with performing a radar beam sweep during a DL phase of operation by the network10, the device12adapts its radar transmissions to avoid transmitting in one or more radar beam directions30and/or reduces its radar-signal transmission power in one or more radar beam directions. Such adaptations are not limited, however, to networks using the described UL/DL TDD phases. In at least some embodiments of the device12and/or in at least some embodiments of an associated method of operation, the device12mitigates or avoids radar interference with respect to DL reception operations by given devices32in a currently-known set34of neighboring devices32.

FIG.2illustrates another example implementation of the network10, as a Fifth Generation (5G) network having functional elements, interconnections, and operations according to the 5G TS released by the 3GPP. The RAN20comprises a Next Generation (NG) RAN wherein one or more radio network nodes provide New Radio (NR) air interfaces.

In particular, in the example depiction, the RAN20includes radio network nodes22configured as “gNBs” that provide NR air interfaces using the millimeter wave (mmW) frequency range-see the nodes22-1and22-2configured as gNBs and providing radio coverage in respective coverage areas40-1and40-2. Coverage may be omnidirectional or beamformed or a mix of omnidirectional and beamformed coverage. Additionally, one or more radio network nodes22are configured as ng-eNBs, which provide Fourth Generation (4G) Long Term Evolution (LTE) air interfaces but couple to the 5GC-see the nodes22-3and22-4, providing radio service in respective coverage areas40-3and40-4.

The respective coverage areas40may overlap at least partly, meaning that NR and LTE air interfaces may be available to a device12operating in a location having overlapping coverage, and it should be understood that the devices12and32depicted in the diagram are shown merely for example. A greater or lesser number of devices may be using the network10and may have any given distribution among the respective coverage areas. It should also be understood that radar transmissions from a given device12may interfere with the DL reception operations at essentially any other type of device32, regardless of whether the other device32is radar-enabled, to the extent that such transmissions are in frequency range relevant to the DL transmissions.

FIG.3offers an illustrative example, where radar signals transmitted by a device12potentially interfere with the reception at a neighboring device32of DL signals transmitted by a radio network node22of a wireless communication network—i.e., one or more radar beam directions30used by the device12may be problematic with respect to DL reception operations at the neighboring device32. In this example, the device12is configured for communicating with a wireless communication network and performing radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range and the device12includes communication circuitry50that is configured for wireless communications with respect to the wireless communication network, e.g., the network10, and for radar transmissions.

In an example implementation, the communication circuitry50comprises receiver circuitry52(NW RX52) and transmitter circuitry54(NW TX54) that is configured for receiving DL signals from given radio network nodes22of the network10and for transmitting UL signals to given nodes22of the network10. The communication circuitry50also includes a radar sub-system56that is configured for radar probing—i.e., surrounding-environment sensing based on transmitting radar signals and receiving reflected radar signals in return. In an advantageous but non-limiting example, the radar subsystem56reuses all or at least a portion of the circuitry (and antennas) used for communicating with the network10—e.g., reuse of at least a portion of the receiver circuitry52and the transmitter circuitry54, based on performing radar-signal transmissions in a mmW frequency range that is the same as or overlaps with one or more of the mmW frequency ranges used for communicating with the network10. Of course, the radar subsystem56also may include additional circuitry, such as reception-timing circuitry used to measure return reflections of the transmitted radar signals and it may interface with and/or reuse portions of processing circuitry60included in the device12.

The processing circuitry60comprises fixed circuitry or programmatically-configured circuitry or a mix of both types of circuitry. In non-limiting example implementations, the processing circuitry60comprises or includes digital processing circuitry, such as one or more microprocessors, Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Systems on a Chip (SoC) circuits, etc., along with supporting circuitry, such as clocking, interfacing, and power-management circuitry.

In at least one implementation, the processing circuitry60comprises one or more computer circuits that are specially adapted to carry out the device-side operations described in any of the device-related embodiments described herein, based at least in part on the execution of computer program instructions stored in a computer-readable media. To that end, in at least one embodiment, the device12includes storage62comprising one or more types of computer-readable media that store one or more computer programs (CP)64and may store related configuration data (CFG. DATA)66. The storage62comprises one or more types of memory circuits or devices and/or one or more types of storage devices, such as volatile working memory for program execution and non-volatile memory for longer-term program storage. Examples include SRAM, DRAM, FLASH memory, EEPROM, Solid State Disk (SSD), etc. Such memory provides for non-transitory storage, which does not necessarily mean unchanging or permanent storage but does connote storage of at least some persistence.

The processing circuitry60is operatively associated with the communication circuitry50, e.g., it uses the communication circuitry50to exchange data and control signaling with the network10and/or it controls operations of the communication circuitry50. Further, in an example implementation, the processing circuitry60is configured to carry out several device-side operations for avoiding or mitigating DL interference caused by radar transmissions from the device12.

In an example embodiment of the device12, the communication circuitry50is configured to communicate with a wireless communication network10and perform radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. That is, the device12performs radar probing using mmW frequencies that are the same as or are relevant to the mmW frequencies used by the wireless communication network10for transmitting DL signals.

The processing circuitry60of the device12is operatively associated with the communication circuitry50and is configured to determine, for each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, whether there are any neighboring wireless communication devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from the network10and, if so, identify the radar beam direction30as being an interfering radar beam direction30. Such an arrangement can be understood as the processing circuitry60being configured to classify respective ones of the radar beam directions30as being restricted or unrestricted-where “restricted” means that radar transmissions by the device12in the respective radar beam direction30are known or estimated as causing DL reception interference at a neighboring device32, and “unrestricted” means that radar transmissions by the device12in the respective radar beam direction30is known or estimated as not causing DL reception interference at a neighboring device32. The beam classifications may be updated by the processing circuitry60in response to a change in any condition or circumstance bearing on the classifications.

The processing circuitry60is configured to perform, responsive to identifying one or more interfering radar beam directions30, DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring wireless communication devices32. As one example, the assistance information comprises interference-suppression information—e.g., signal timing, resource usage, or other signal-structure information-that enables a vulnerable neighboring device32to suppress the interfering radar signal via interference cancelation. As another example, the assistance information comprises position and/or orientation information of the device12, or position/orientation information relative to a neighboring device32, such that the neighboring device32can select a different DL transmit beam and/or DL receive beam, for use in receiving DL signals from its serving radio network node22.

In at least one embodiment, the wireless communication network10comprises a RAN20having a TDD configuration that defines alternating phases of operation consisting of a DL phase. The RAN20transmits DL signals to given wireless communication devices12,32, and an UL phase, wherein the RAN20receives UL signals from given wireless communication devices12,32. The device12in one or more embodiments is configured for operation according to 5G network standards released by the 3GPP.

To determine whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12, in at least one embodiment the processing circuitry60is configured to perform, via the communication circuitry50, a radar beam sweep through the plurality of radar beam directions30using a defined transmission power, and receive feedback information indicating whether or what extent the radar transmissions comprised in the radar beam sweep were detected by one or more other wireless communication devices32. For example, the feedback indicates signal-strength measurements made by the other devices32on reference signal transmissions made by the device12during the radar beam sweep. The radar beam sweep uses the radar beam directions30or uses beam directions that correspond to theme.g., each beam direction used for the sweep directionally aligns with a radar beam direction30.

To receive the feedback information, the processing circuitry60in one or more embodiments is configured to receive, via the communication circuitry50, the feedback information from the other device(s)32directly via Device-to-Device (D2D) signaling or indirectly via Over-The-Top (OTT) signaling conveyed from the other device(s)32to the device12via the network10. That is, the OTT signaling represents communications between the device(s)32and the device12that are exchanged via the network10, such as by each other device32establishing a communication session with the device12.

In an example scenario, the one or more other devices32comprise or belong to a currently-known set34of neighboring devices32, as known to the device12via detection of UL signal transmissions by given neighboring devices32or via D2D discovery operations or via the reception of neighboring-device information from the network10. Correspondingly, in at least some embodiments of a radio network node22, the radio network node22is configured to send assistance information to a device12—i.e., a radar-enabled UE—that identifies the currently neighboring devices32. The node22determines such information based on obtaining or determining the respective positions of the devices12and32.

The processing circuitry60in one or more embodiments is configured to transmit, via the communication circuitry50, configuration information for the currently-known set34of neighboring devices32directly via D2D signaling or indirectly via OTT signaling. The configuration information indicates a time at which the radar beam sweep will be performed or radio resources to be used for the radar beam sweep. Such information enables the neighboring device(s) to make measurements during the radar beam sweep that indicate whether or to what extent radar transmissions by the device12cause or are expected to cause DL reception interference at the respective neighboring devices32.

The processing circuitry60in one or more embodiments is configured to receive the feedback information-as generated by the neighboring device(s)32—as DL control signaling from the network10. The DL control signaling is based on the one or more other devices32sending Channel State Information CSI reports to the network10that are based on received-signal measurements made by the one or more other devices32during the radar beam sweep. The CSI reports may be the same as or based on the reporting structure, reporting channels, etc., used for “legacy” reporting of CSI by the devices32with respect to their reception of DL signals from their serving radio network node(s)22. Further, in terms of the DL signaling being based on the feedback from the neighboring device(s)32, the DL signal may convey the feedback or otherwise indicate the feedback or may be derived from the feedback.

The processing circuitry60in one or more embodiments is configured to determine whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12by, for neighboring devices32currently known to the device12, obtaining position and/or orientation information for respective ones among the known neighboring devices32. The processing circuitry60obtains such information either based on the device12directly receiving it via D2D signaling or indirectly receiving it via OTT signaling conveyed through the network10. The processing circuitry60in such embodiments is further configured to evaluate the position information and/or orientation for each known neighboring device32in relation to the current position and orientation of the wireless communication device12.

The processing circuitry60in one or more embodiments is configured to determine whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12by detecting UL transmissions by one or more other devices32and evaluating received-signal strengths of the detected UL transmissions.

In one or more embodiments, the processing circuitry60is configured to obtain position information for respective ones of the one or more other devices32, use the position information and the received-signal strengths to estimate path losses between the device12and respective ones of the one or more other devices32, and determine whether any of the one or more other devices32are vulnerable, based on the received-signal strengths and the estimated path losses. In at least one embodiment, the processing circuitry60is further configured to obtain orientation information for respective ones of the one or more other devices32, because the orientation indicates the directions of the beams of the respective other device(s)32, or at least provides a basis for determining those directions.

The processing circuitry60in one or more embodiments is configured to perform the DL interference mitigation by avoiding radar transmissions in the interfering radar beam directions30or adapting transmission power for radar transmissions in the interfering radar beam directions30. Further, in at least some embodiments, the processing circuitry is configured to update, in response to fulfillment of a triggering condition, the determination of whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12, and update the adaptation of the radar transmissions or transmit updated assistance information.

The triggering condition is any one or more of: detecting more than a threshold change in position or orientation of the device12; receiving information indicating more than a threshold change in position or orientation of any neighboring devices32; detecting more than a threshold change in one or more conditions of a surrounding physical environment of the device12that bear on propagation of radar transmissions by the device12; a change in transmission frequency or bandwidth used by the device12for radar transmissions; or expiration of an update timer started in relation to a most-recent iteration of determining whether there are any neighboring devices32vulnerable to interference from radar transmissions by the wireless communication device12.

The other wireless communication devices32may or may not be radar-enabled devices and may or may not be of the same type as the example device12. However,FIG.3illustrates than a neighboring other device32may comprise communication circuitry80, with network receiver circuitry82and network transmitter circuitry84, processing circuitry90, storage92, which may store one or more computer programs94and configuration data96. The device32also may include one or more antenna panels70for communicating with a wireless communication network10.

FIG.4illustrates another embodiment, comprising a method400of operation performed by a wireless communication device that communicates with a wireless communication network and performs radar transmissions for surrounding-environment sensing. In an example scenario, the device and network in question are the device12and the network10described earlier. Using that example scenario, the method400includes the device12performing a determining operation (Block402). For each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, the device12determines whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from the network. If so (YES from Block404), the method400includes the device12identifying (Block406) the radar beam direction30as being an interfering radar beam direction30.

The method400further includes, responsive to the device12identifying one or more interfering radar beam directions30, the device12performing (Block408) DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring devices32. If the device12does not identify any vulnerable neighboring devices32(NO from Block404), the method400includes the device12performing radar transmissions without restrictions (Block410)-i.e., it does not adapt or control its radar transmissions in specific consideration of known or estimated DL reception interference at a neighboring device32.

Determining (Block402) whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12comprises, for example, the device12performing a radar beam sweep through the plurality of radar beam directions30using a defined transmission power, and receiving feedback information indicating whether or what extent the radar transmissions comprised in the radar beam sweep were detected by one or more other devices32. The feedback information may be received from one or more other devices32directly via D2D signaling or indirectly via OTT signaling conveyed from the one or more other devices32to the device12via the network10.

In at least one example scenario, the one or more other devices32comprise or belong to a currently-known set34of neighboring devices32, as known to the device12via detection of UL signal transmissions by given neighboring devices32or via D2D discovery operations or via the reception of neighboring-device information from the network10. The method400may include or be based on the device12repeatedly looking for or discovering neighboring devices32, and it will be understood that the number, distance, and orientation of neighboring devices32may change over time, e.g., with movement of the device12or with movement of the other devices32around it. Further, other conditions may change, such as changes in the frequency/frequencies used by the device12and/or changes in the ambient environment, that trigger the device12to reassess whether there are any vulnerable neighboring devices32. Another item or condition that may change is the “beam pairing” in use for any given neighboring device32, where “beam pairing” refers to the beam pairing between the device32and its serving radio network node22. Radar sensing by the device12may interfere with communications conducted on one beam pairing but not on another beam pairing (or at least not cause interference above some acceptable threshold). Thus, a change in beam pairing at a neighboring device32may change which directions should be considered restricted or unrestricted by the device12, with respect to radar sensing.

One or more embodiments of the method400include the device12transmitting configuration information for the currently-known set34of neighboring devices32directly via D2D signaling or indirectly via OTT signaling. The configuration information indicates a time at which the radar beam sweep will be performed or radio resources to be used for the radar beam sweep. Such information enables neighboring devices32to listen for the radar transmissions of the radar beam sweep.

Receiving the feedback information in one or more embodiments of the method400comprises the device12receiving DL control signaling from the network10. The DL control signaling is based on the one or more other devices32sending CSI reports to the network10that are based on received-signal measurements made by the one or more other devices32during the radar beam sweep. The same radio network node22of the network10may serve the device12and the one or more other devices32, in which case the radio network node10natively has access to the CSI reports for sending the DL control signaling to the device12. Alternatively, two or more radio network nodes22are involved in receiving the CSI reports and sending the DL control signaling and they may rely on inter-node signaling to exchange the involved data and/or coordination and control signaling.

In at least one implementation, the determining operation (Block402) of the method400comprises, for neighboring devices32currently known to the device12, obtaining position and/or orientation information for respective ones among the known neighboring devices32directly via D2D signaling or indirectly via OTT signaling conveyed through the network10. The determining operation (Block402) in this example implementation further includes the device12evaluating the position and/or orientation information for each known neighboring device32in relation to the current position and orientation of the device12. For example, the device12evaluates the position/orientation information for the device12and a neighboring device32, to determine whether any of its radar beam directions30are pointing at the neighboring device32.

Determining (Block402) whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12comprises, in one or more other example embodiments, the device12detecting UL transmissions by one or more other devices32and evaluating received-signal strengths of the detected UL transmissions.

The method400may also include the device12obtaining position information for respective ones of the one or more other devices32, and using the position information and the received-signal strengths to estimate path losses between the device12and respective ones of the one or more other wireless communication devices32. Correspondingly, the device12determines (Block402) whether any of the one or more other devices32are vulnerable, based on the received-signal strengths and the estimated path losses.

Performing (Block408) the DL interference mitigation comprises, for example, the device12avoiding radar transmissions in the interfering radar beam directions30or adapting transmission power for radar transmissions in the interfering radar beam directions30. The device12may use avoidance for all interfering beam directions30, or may use power-reduction for all interfering beam directions30, or may use avoidance or power-reduction for any given interfering beam direction30in dependence on the extent or amount of interference known or estimated with respect to that direction.

For example, the device12may use a lower interference threshold—e.g., expressed in known or estimated received-signal strength-to classify individual radar beam directions30as being restricted or unrestricted. Then, for each restricted direction, if the known or estimated interference is below an upper interference threshold, the device12considers the radar beam direction30as being conditionally restricted, meaning that it does not exclude the direction from radar scanning, but uses a lower transmission power than it would otherwise use when scanning in that radar beam direction30. However, if the known or estimated interference for a restricted direction exceeds the upper threshold, the device12considers that radar beam direction30as being unconditionally restricted and it skips/avoids it when performing radar scanning, e.g., when performing a next radar scan.

Of course, the device12may periodically reassess its radar beam directions30or reassess them on a triggered basis. In at least one embodiment, the method400includes, responsive to fulfillment of a triggering condition, the device12updating the determination of whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12, and updating the adaptation of the radar transmissions or transmitting updated assistance information. By way of example, the triggering condition is any one or more of: detecting more than a threshold change in position or orientation of the device12; receiving information indicating more than a threshold change in position or orientation of any neighboring devices32; detecting more than a threshold change in one or more conditions of a surrounding physical environment of the device12that bear on propagation of radar transmissions by the device12; a change in transmission frequency or bandwidth used by the device12for radar transmissions; or expiration of an update timer started in relation to a most-recent iteration of determining whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12.

Frequency and/or bandwidth changes arise, for example, as a consequence of the network10changing the configuration of the device12, e.g., reconfiguring the frequency range and/or bandwidth used for communications between the device12and its serving radio network node(s)22in the network10. In cases where the device12performs radar scanning at the same frequencies and/or same bandwidths as used for communicating with the network10, or in any situation where the radar-scanning frequencies and/or bandwidths depend on the frequencies/bandwidths used by the device12with respect to the network10, changing communication-frequency/bandwidths affects radar-scanning operations. Environmental changes include, for example, rain starting or stopping or changing in intensity.

FIG.5illustrates another embodiment of a wireless communication device12comprising a set of processing units or modules120. The modules comprise, for example, functional arrangements of processing circuitry and may be implemented, for example, via the execution of computer program instructions.

The illustrated set of modules120includes a determining module122that is configured to determine, for each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from a network10. For any such radar beam directions30, the set of modules120includes an identifying module124that is configured to identify the radar beam direction30as being an interfering radar beam direction30. Further, the set of modules120includes a mitigating module126that, responsive to the identification of one or more interfering radar beam directions30, is configured to perform DL interference mitigation by adapting the radar transmissions or by transmitting assistance information to trigger interference suppression or avoidance by the vulnerable neighboring devices32.

Turning back toFIG.3for a depiction of an example arrangement for a radio network node22, the illustrated node22includes communication circuitry100, including receiver (RX) circuitry102and transmitter (TX) circuitry104. One or more antennas106(or arrays of antenna elements) are associated with the communication circuitry100, for transmitting DL signals to given wireless communication devices and receiving UL signals from such devices.

Further, the node22includes processing circuitry110. The processing circuitry110comprises fixed circuitry or programmatically-configured circuitry or a mix of both types of circuitry. In non-limiting example implementations, the processing circuitry110comprises or includes digital processing circuitry, such as one or more microprocessors, Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Systems on a Chip (SoC) circuits, etc., along with supporting circuitry, such as clocking, interfacing, and power-management circuitry.

In at least one implementation, the processing circuitry110comprises one or more computer circuits that are specially adapted to carry out the network-node-side operations described in any of the node-related embodiments described herein, based at least in part on the execution of computer program instructions stored in a computer-readable media. To that end, in at least one embodiment, the node22includes storage112comprising one or more types of computer-readable media that store one or more computer programs116and may store related configuration data114. The storage112comprises one or more types of memory circuits or devices and/or one or more types of storage devices, such as volatile working memory for program execution and non-volatile memory for longer-term program storage. Examples include SRAM, DRAM, FLASH memory, EEPROM, Solid State Disk (SSD), etc. Such memory provides for non-transitory storage, which does not necessarily mean unchanging or permanent storage but does connote storage of at least some persistence.

The processing circuitry110is operatively associated with the communication circuitry100, e.g., it uses the communication circuitry100to send and receive wireless signaling to/from wireless devices. In one or more examples, the processing circuitry110is configured to receive, via the communication circuitry100, feedback from one or more other wireless communication devices32neighboring a wireless communication device12that communicates with the wireless communication network10and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other device32comprises, for example, measurements made by the other device32on reference signal transmissions by the device12, such as reference-signal transmissions in a radar beam sweep by the device12.

Further, the processing circuitry110is configured to send, via the communication circuitry100, DL signaling for the device12. The DL signaling is based on the feedback from the one or more other devices32and thereby enables the device12to determine, for each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from the network10.

In one or more embodiments, the processing circuitry110is configured to receive the feedback as Channel State Information (CSI) reports from the one or more other devices32, where the CSI reports are based on received-signal measurements made by the one or more other devices32during a radar beam sweep performed by the device12.

FIG.6illustrates an example method600performed by a radio network node22of a wireless communication network10. The method600includes the radio network node22receiving (Block602) feedback from one or more other wireless communication devices32neighboring a wireless communication device12that communicates with the network10and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other device32comprises measurements made by the other device32on reference signal transmissions by the device12. Further, the method600includes the radio network node22sending (Block604) DL signaling for the device12.

The DL signaling is based on the feedback from the one or more other devices32and thereby enables the device12to determine, for each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from the network10.

Receiving (Block602) the feedback information comprises, for example, the radio network node22receiving CSI reports from the one or more other devices32. Here, the CSI reports are based on received-signal measurements made by the one or more other devices32during a radar beam sweep performed by the device12.

FIG.7illustrates another embodiment of a radio network node, e.g., another example implementation for the node22introduced inFIG.1. Here, the node22comprises a collection of processing units or modules130, which may be functional processing units implemented via underlying processing circuitry. The modules130may, for example, be implemented as virtual processing elements in a virtualization environment, such as may be hosted by a computer server in a data center that may be remote from the physical-layer circuitry used to anchor the radio air interface.

The depicted modules130include a receiving module132that is configured to receive feedback from one or more other wireless communication devices32neighboring a wireless communication device12that communicates with the network10and performs radar transmissions for surrounding-environment sensing using a same or overlapping mmW frequency range. The feedback from each other device32comprises measurements made by the other device32on reference signal transmissions by the device12. Further, the radio network node22includes a sending module134that is configured to send DL signaling for the device12.

The DL signaling is based on the feedback from the one or more other devices32and thereby enables the device12to determine, for each radar beam direction30among a plurality of radar beam directions30relative to a current orientation and position of the device12, whether there are any neighboring devices32vulnerable to interference from radar transmissions by the device12with respect to receiving DL communication signals from the network10. The receiving module132is configured to receive the feedback, for example, as CSI reports that are based on received-signal measurements made by the one or more other devices32during a radar beam sweep performed by the device12.

The techniques described above in the various embodiments allow a radar-enabled wireless communication device12, also referred to as a radar-enabled User Equipment (UE), to avoid causing interference towards other UEs when the radar-enabled UE performs radar sensing. In an example implementation, the radar-enabled UE is configured for operation in a 5G network and its mitigation operations avoid or reduce DL reception interference at surrounding UEs during the DL phase of the network’s UL/DL TDD operation.

Multiple approaches are contemplated, including UE-coordinated DL interference mitigation that is autonomous—i.e., it does not require network support and relies on interference mitigation via interference sensing. For example, the radar-enabled UE may employ a sidelink (D2D) or OTT-based messaging approach to collect DL interference information experienced by surrounding UEs while it sweeps the radar beam. The Inertial Measurement Unit (IMU) information of the radar-enabled UE and other UEs may also be collected because the IMU information indicates the direction of the radar signal source and the listening UE. The radar-enabled UE uses this information to select the radar beam directions and/or adjust the transmitted power of the radar signal in respective radar beam directions such that the interference caused to other UEs is below the threshold. Sharing the positioning data of the other UEs is an optional step that further improves the technique. Rather than listening for radar transmissions from the radar-enabled UE using all their antenna panels and receive (Rx) beams, the surrounding UEs may be configured to save power by listening for radar interference using only the panels/beams that are paired with their serving radio network nodes22in the network10. The radio network node(s)22may be referred to as base stations (BSs).

In at least one embodiment, the radar-enabled UE supports beam correspondence and, during a scenario where it is free of network-related communication tasks during the UL phase of TDD operations, it senses the UL transmissions of the surrounding UEs to identify the radar beam directions that are deemed problematic in terms of causing DL reception interference at the surrounding UEs. That is, the radar-enabled UE listens for the UL transmissions from surrounding UEs using the same or aligned beam directions used by it for performing radar transmissions, based on the correspondence or reciprocity between Tx and Rx beams at the radar-enabled UE, and it uses the received signal power of the UL signals it receives to estimate the amount of radar interference that would be experienced at the corresponding surrounding UEs.

Interference mitigation may also include or be based on information sharing, where the radar-enabled UE and the surrounding UEs share position and IMU information and paired-beam information using D2D or OTT messaging. The radar-enabled UE uses such information to adjust the direction and power level of its radar transmissions. In addition, the radar-enabled UE in at least one embodiment asks the surrounding UEs to change the beams used by them for pairing with their serving BSs, to thereby avoid radar interference during the DL phase. The surrounding UEs can share the time, frequency, panel identification, and/or beam information with the radar-enabled UE, with the radar-enabled UE using that information to adapt its radar transmissions, to avoid the times, frequencies, and spatial dimensions relevant to DL reception at the surrounding UEs.

Other embodiments use network-coordinated DL interference mitigation where one or more such approaches do not require cooperation among all of the involved UEs. In at least one embodiment, the wireless communication network configures the surrounding UEs in a cell or in a cell region to report the interference levels they experience from radar transmissions by a radar-enabled UE. In a particular example, the serving BS(s) associated with the surrounding UEs configure them to use “legacy” CSI reporting mechanism, e.g., LTE, or NR Frequency Range 1 (FR1), to report the interference levels they experience with respect to the radar-enabled UE performing a radar beam sweep. This approach does not require sidelink or OTT based sharing of interference-sensing information between the radar-enabled and surrounding UEs.

Among the multiple advantages attending one or more of the embodiments disclosed herein is the mitigation of interference experienced at one or more UEs with respect to the reception of DL signals from a wireless communication network, in a case where another nearby UE is radar-enabled and performs radar scanning of its surrounding environment using radar signals that are in the same frequency range as the DL signals. For example, a given UE includes a mmW transceiver that is configured for sending and receiving communication signals to/from a wireless communication network, and the UE uses the mmW transceiver for transmitting radar signals, for surrounding-environment sensing.

As noted, the radar-enabled UE and the proximate (surrounding) UEs may cooperate to mitigate the radar interference without need for network assistance. Alternatively, the surrounding UEs use a CSI reporting mechanism to the network, and the network conveys that information to the radar-enabled UE. The various embodiments allow for complementary radar scans because some beams of the radar-enabled UE may be restricted during the UL phase of the network’s operation, while the same beams may be unrestricted during the DL phase of the network’s operation. One or more of the various embodiments also contemplate controlling whether or to what extent radar transmissions are restricted in dependence on the criticality of the communications that are subject to the interference and/or a likelihood that the radar transmissions will interfere with communication signals of the network.

In 5G NR, the UE and the BS use the mmWave frequencies-denoted as Frequency Range 2 or FR2-in TDD mode for communication. Although using this frequency range opens a wide spectrum, it is highly susceptible to blockage and attenuation. Hence, communications between a UE and its serving BS rely on finding a suitable pairing of Tx/Rx beams. If another, nearby UE performs radar scanning, its radar transmissions may interfere with UL reception at network BSs or DL reception at nearby UEs, in dependence on whether the radar transmissions coincide with the UL or DL phase of TDD operation. The level of interference depends on the distance between the radar-enabled UE and the other UEs. Depending on the distance and orientation of the other UEs, the radar-enabled UE may change the strength or direction of the radar signals adaptively. Alternatively, the surrounding UEs may use time, frequency, or spatial domain adaptations to avoid/reduce the interference they experience, or they may switch to other beams directions for coupling to the network, to avoid the radar interference.

Taking an example case where there is a radar-enabled UE and one or more surrounding UEs, an embodiment of radar interference mitigation contemplated herein involves DL sensing by the surrounding UEs. In an example implementation, the radar-enabled UE sends a “test” radar signal and the surrounding UEs, which can be in the current or neighboring cells of the wireless communication network, evaluate their experienced DL interference. The surrounding UEs report the interference levels for the different radar beam directions via OTT or D2D messaging to the radar-enabled UE. Then, the radar-enabled UE adjusts its radar signal power in the radar beam directions that are problematic, as assessed from reported levels of DL interference experienced at respective ones of the surrounding UEs. In one embodiment, the radar-enabled UE may use the UL Sounding Reference Signal (SRS) as a “test” radar signal and the other UEs perform “DL measurements” during a signaled UL SRS sweep interval.

In at least one embodiment, one or more of the surrounding UEs have analog beamforming capability, and they sequentially listen through all beams of their antenna panels or only listen through the panels and beams that are paired with their serving BS(s). They collect samples through the antenna elements of their antenna panels and process them in baseband. A surrounding UE with digital beamforming capability may “listen” for radar interference through all of its beams at the same time.

Use of the radar “test” scan at the radar-enabled UE and the corresponding “listening” at the surrounding UEs requires time synchronization among the radar-enabled and the surrounding UEs and may involve sharing position and IMU information of the surrounding UEs and/or radar-enabled UE, radar beam indexes, transmission time of the radar signal, the radar sweep interval, the time/frequency resource allocations used for transmission of the radar beams during the test sweep, and radar code information. As noted, such information can be shared via D2D or OTT messaging. If the beam sweep sequence of the radar-enabled UE is known and the UEs are synchronized, it is unnecessary to share the radar beam index.

FIGS.8A/Billustrate a corresponding method800of operation where a radar-enabled UE installs and runs an OTT or sidelink application for sharing information with other UEs (Block802). The radar-enabled UE defines or otherwise selects an area of interest for radar scanning, which may be defined in terms of angular ranges for scanning the surrounding environment (Block804), and it synchronizes with neighboring UEs regarding its performance of one or more radar-signal test sweeps (Block806)-e.g., it shares the sensing time, sweep interval, radar beam indexes, radar-signal information, IMU information, and it may receive information from the neighboring UEs, such as IMU information, etc.

The radar-enabled UE then transmits test radar signals—i.e., performs the test sweep via selected beams from selected antenna panels of the radar-enabled UE (Block808). Here, the selected beams/panels correspond to the area of interest for radar scanning. The radar-enabled UE receives (via OTT or sidelink message) indications of the measurement results from the neighboring UEs (Block810). As noted, each neighboring UE may “listen” for the test sweep by the radar-enabled UE using all of its beams/panels or just a subset of them, such as just the beams/panels that it currently uses for coupling to the wireless communication network.

The radar-enabled UE checks whether conditions have changed (Block812), where the “conditions” considered include changed frequency ranges, changed environmental conditions, changed position and/or orientation, or essentially any change that bears on whether or to what extent its radar transmissions may interfere with network communications involving other UEs. The check may be conditioned on defined thresholds, e.g., such that more than a marginal change is required. If the condition(s) have changed (YES from Block812), processing returns to Block804. If not (NO from Block812), the radar-enabled UE assesses the information returned to it for the test sweep and determines whether there are any vulnerable neighboring UEs (Block812). Here, a “vulnerable” UE is a neighboring UE that experienced more than a threshold amount of interference during the test sweep.

If there are one or more vulnerable UEs (YES from Block812), processing continues with the radar-enabled UE determining whether the interference problem(s) can be addressed via power control (Block814). In making this assessment, the radar-enabled UE considers whether its radar transmissions in any problematic beam direction can be reduced in power to a level that reduces the interference experienced at the affected neighboring UE(s) to an acceptable level while still having sufficient power to yield meaningful radar-scanning results. The level of power that is sufficient in this regard will depend on the nature or purpose of the scanning; likewise, the acceptable level of interference may be a fixed threshold or may be a variable threshold that depends on the criticality of the affected communications or other factors.

If the interference vulnerabilities can be addressed with power control (YES from Block814), processing continues along path “B”. If not (NO from Block814), processing continues along path “C”. If there are no vulnerable neighboring UEs (NO from Block812), processing continues with the radar-enabled UE performing the radar scan over the area of interest without restrictions (Block816)—i.e., without spatial restrictions that involve skipping transmissions in certain beam directions and/or reducing transmission power in certain beam directions. From there, processing continues along path “A”.

As seen inFIG.8B, the path-A processing includes the radar-enabled UE determining whether there are any further areas to scan. If so, (YES from Block818), processing returns to Block804. If not, (NO from Block818), processing “ends” at least for purposes of the current cycle of radar scanning.

The path-B processing includes the radar-enabled UE performing the radar scan over the area of interest using directionally-based transmit power control (Block820). That is, in the radar beam directions30that correspond to neighboring UEs determined to be vulnerable to radar interference, the radar-enabled UE adapts the transmit power it uses for the radar signal. Upon completion of the scan, processing continues to Block818.

The path-C processing includes the radar-enabled UE determining whether the radar interference vulnerabilities can be addressed via beam switching at the vulnerable neighboring UEs (Block822). Here, “beam switching” refers to a vulnerable UE changing the Tx/Rx beam pair that is used between the wireless communication network and the vulnerable UE for DL signal transmission/reception. Depending on the beam arrangements in play and the position of the vulnerable UE relative to its serving BS and the radar-enabled UE, there may be a beam pairing for which the neighboring UE will experience no radar interference or interference of an acceptably low amount.

If the interference problem is addressable via beam switching (YES from Block822), the method800continues with initiating or otherwise triggering beam switching at the vulnerable UE(s) (Block824). In one example, the radar-enabled UE initiates the beam switching via signaling towards the vulnerable LTE(s). In another example, the vulnerable UE(s) indicate to the radar-enabled UE whether beam switching can be used to address the interference problem and they initiate the switch and, possibly, confirm the switch to the radar-enabled UE. From there, processing progresses to Block818.

If the interference problem is not addressable via beam switching (NO from Block822), processing returns to Block804. That is, the NO path from Block822corresponds to a scenario where the interference problem cannot be solved by spatially-dependent power control of the radar transmissions and cannot be solved by beam switching at the vulnerable UEs. As such, the UE returns to Block804, for defining/selecting an area of interest for radar scanning. While the processing of Block804may initially comprise the radar-enabled UE simply selecting a desired area for scanning, upon returning to Block804from Block822, the radar-enabled UE may select/define a radar scanning area that excludes directions associated with the vulnerable UEs.

Now consider embodiments that involve network-coordinated DL interference mitigation via sensing, where such embodiments provide a robust, non-autonomous mode of interference mitigation. While such embodiments require support of the involved wireless communication network, they have the advantage of not requiring cooperation between all involved UEs.

The network cooperates and may configure UEs in a cell or in a region of a cell to report interference levels via a legacy CSI reporting mechanism. Periodic and aperiodic reporting are available. In this approach, the Channel State Information Reference Signal (CSI-RS) resources are defined but the BS transmits no signal on the defined resources. As such, the designated resources may be denoted as zero-power CSI-RS resource. Rather than the BS transmitting CSI-RS on the zero-power CSI-RS resources, the radar-enabled UE uses them to perform test radar transmissions—a test radar beam sweep—and the surrounding UEs perform measurements on the zero-power CSI-RS resources to assess the level of interference they experience with respect to the radar transmissions. The surrounding UEs send corresponding measurement reports to the network, which then determines whether any of them would experience unacceptable levels of DL interference as a consequence of the radar transmissions, or the network forwards the report(s) to the radar-enabled UE for such assessment.

FIG.9illustrates an example method900of operation, for network-supported interference mitigation. The radar-enabled UE defines the area of interest for radar scanning (Block902), and the BS synchronizes the radar-enabled UE and its surrounding UEs and shares the relevant information among the UEs (Block904), e.g., the zero-power CSI-RS allocations, beam sweep timing, beam indexes, etc.

Operations continue with the radar-enabled UE transmitting test signals via the selected beams and selected antenna panels, as determined by the defined area of the radar scan (Block906) and the surrounding UEs sweep through all or a subset of their Rx beams, such a just the beams currently used for receiving DL signals from their serving BS(s), and measure the interference experienced from the test signals transmitted by the radar-enabled UE (Block908). The surrounding UEs report the interference measurements and corresponding beam indexes to the BS (Block910), and the BS sends information to the radar-enabled UE indicating the reported interference measurements and corresponding beam indexes (Block912).

The radar-enabled UE uses the information received from the BS to select the radar beam directions and/or the directional powers to use for radar scanning, to avoid causing more than a threshold level of DL reception interference at the surrounding UEs (Block914). The radar-enabled UE then performs radar scanning according to the selected directions/powers (Block916). If there are further areas to scan (YES from Block918), processing returns to Block902. If not, (NO from Block918), processing “ends” at least with respect to the current cycle of interference assessment and radar scanning.

In at least one embodiment, the radar-enabled UE has Tx/Rx beam correspondence and it supports UL sensing and it is configured to listen to the UL transmissions of the surrounding UEs during one or more UL phases of the network’s TDD operation, to identify radar beam directions30that are problematic—i.e., that are expected to cause unacceptable levels of DL reception interference at a neighboring UE. In more detail, the received-signal power experienced at the radar-enabled UE for an UL signal received from a surrounding UE for a given Rx beam direction at the radar-enabled UE directly suggests the level of interference that the surrounding UE would experience during the DL phase from a radar transmission by the radar-enabled UE on the reciprocal Tx beam direction. Such operations assume that the orientation and the position of the sensed UEs remain fixed in one UL-DL period.

The surrounding UEs may infrequently transmit uplink signals, hence, the radar-enabled UE needs sufficiently long scan periods to sense the UL transmission of the surrounding UEs. The surrounding UEs can share the time/frequency of their uplink transmission with the radar-enabled UE via sidelink or OTT messaging, for more accurate UL sensing by the radar-enabled UE.

Another embodiment of interference mitigation relies on the use of sidelink or OTT messaging to exchange information between the radar-enabled UE and the surrounding UEs, but does not involve a “test” radar sweep by the radar-enabled UE to assess the interference vulnerabilities of the surrounding UEs. The radar-enabled and the other UEs share the following information: the position of the surrounding UEs, the orientation of the surrounding UEs, e.g., using the IMU information, the beams of the panels of the surrounding UEs that are paired with the BS for network-based communications, the inactivity period(s) of the surrounding UEs, the properties of the radar signal to be transmitted by the radar-enabled UE, e.g., in terms of waveform and sequence, the identity (ID) of the radar-enabled UE, and the time/frequency of the radar transmission.

Interference mitigation then involves one or more of: the radar-enabled UE performing radar scanning when the surrounding UEs are inactive, the radar-enabled UE uses the shared information to adjust the radar signal strength and/or skip transmissions in certain directions, one or more of the surrounding UEs switching to another beam to receive DL signals and thereby avoid radar interference, or the surrounding UEs using the shared characteristics of the radar signal to configure their radiofrequency (RF) receiver circuitry or corresponding baseband processing circuitry to suppress the radar inference.

FIGS.10A/Billustrates yet another method1000of mitigating interference associated with radar transmissions from a radar-enabled UE, with respect to DL reception operations at one or more other UEs that are proximate to the radar-enabled UE. Here, it may be noted that the term “UE” does not denote equipment of a specific type or purpose and may be used broadly to describe a varied mix of equipment types, which may include one or more types of Machine-to-Machine (M2M) or Intemet-of-Things (IoT) devices. However, the term does generally denote a communication apparatus that is operative to use a communication network, e.g., for accessing one or more communication services, but is not a dedicated or fixed part of the network. For example, a UE accesses the network based on having or being associated with subscription credentials that provide a basis for authenticating and authorizing the UE for such access.

In the example ofFIGS.10A/B, the method1000includes the radar-enabled UE installing/running a sidelink or OTT application for sharing information with other UEs (Block1002), e.g., any given other UEs that are proximate to it at a given point in time. The method1000further includes the radar-enabled UE defining/selecting an area of interest for radar scanning (Block1004) and acquiring the position and orientation of the surrounding UEs, along with obtaining its own position and orientation (Block1006). “Position” may be expressed as a geographic location, e.g., as determined from a Global Navigation Satellite System (GNSS), and orientation may be indicated by IMU information, e.g., as determined by the respective UEs from internal accelerometers or gyroscopic sensors.

The radar-enabled UE further acquires information indicating the BS-paired beams of the surrounding UEs (Block1008), e.g., in terms of their relevance to the radar beam directions of the radar-enabled UE for its current position and orientation. The method1000further includes the radar-enabled UE determining whether radar signals sent through desired radar beam directions (corresponding to the area of interest) result in DL interference at any of the surrounding UEs (Block1010). If not, processing continues along path “B”. If so, processing continues with the radar-enabled UE determining whether it can address the interference issue by tuning (adapting) the transmit power it uses in the involved beam directions, to avoid causing the interference (and this may be determined in view of some threshold limit on the maximum level of interference that is deemed acceptable or tolerable at the victim UE) (Block1012).

If the interference issues are assessed as being addressable via transmit power tuning (NO from Block1012), processing continues along path “C”. If not, processing continues to Block1014, where the radar-enabled UE assesses whether the interference problem can be addressed via beam-switching at the surrounding UEs that are vulnerable to the interference. If beam-switching is available as a solution, processing continues with path “A” and otherwise processing returns to Block1004.

FIG.10Billustrates the processing paths A, B, and C, with processing path A involving a switch of the BS-pairing beams at the affected (vulnerable) ones of the surrounding UEs (Block1016) and the radar-enabled UE performing the radar scan without spatial restrictions (Block1018). Processing path B does not involve or require beam-switching at the vulnerable UEs, and also includes performing the radar scan without spatial restrictions (Block1018). Processing path C also does not involve beam-switching at the vulnerable UEs but does involve the radar-enabled UE performing the radar scan with spatial restrictions (Block1020), where the restrictions are directionally-dependent power tunings that reduce radar-signal power in the radar beam directions associated with the vulnerable UEs.

All three processing paths A, B, and C flow into Block1022, in which the radar-enabled UE determines whether there are further areas in which to perform radar scans. If not, processing ends at least for purposes of the current radar-scanning cycle. If so, processing returns to Block1004.