Patent Description:
<CIT> and <CIT> disclose operations and measurements relating to full duplex communication with beam selection.

In one example, a method of wireless communication at a user equipment (UE) is disclosed. The method may include receiving, from a base station, configuration information for performing beam pair selection measurements with respect to a subset of candidate beams at the UE, the beam pair selection measurements including at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams, wherein the configuration information indicates measurement gaps between the self-interference measurements. The method may further include performing the beam pair selection measurements based on the configuration information, selecting at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements, and transmitting a report including the selected at least one pair of Tx/Rx beams to the base station.

In one example, a method of wireless communication at a base station (BS) is disclosed. The method may include transmitting, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE, the beam pair selection measurements including at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams, wherein the configuration information indicates measurement gaps between the self-interference measurements. The method may further include receiving, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements.

Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform the aforementioned methods as well as those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

These and other aspects of the invention will become more fully understood upon a review of the detailed description in conjunction with the accompanying figures. While features may be discussed relative to certain aspects and figures below, all aspects can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.

The following description and the appended figures set forth certain features for purposes of illustration.

The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

While aspects are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, aspects and/or uses may come about via integrated chip aspects and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In <NUM> NR two initial operating bands have been identified as frequency range designations FR1 (<NUM> - <NUM>) and FR2 (<NUM> - <NUM>). It should be understood that although a portion of FR1 is greater than <NUM>, FR1 is often referred to (interchangeably) as a "Sub-<NUM>" band in various documents and articles.

For example, three higher operating bands have been identified as frequency range designations FR2x (<NUM> - <NUM>), FR4 (<NUM> - <NUM>), and FR5 (<NUM> - <NUM>).

Further, unless specifically stated otherwise, it should be understood that the term "millimeter wave" or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR2x, FR4, and/or FR5, or may be within the EHF band.

As one example, the RAN <NUM> may operate according to 3rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as <NUM>.

The radio access network <NUM> is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a "mobile" apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC), a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA), and a broad array of embedded systems, e.g., corresponding to an "Internet of things" (IoT). A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player), a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid), lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

Referring now to <FIG>, by way of example and without limitation, a schematic illustration of a RAN <NUM> is provided. In some examples, the RAN <NUM> may be the same as the RAN <NUM> described above and illustrated in <FIG>. The geographic area covered by the RAN <NUM> may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. <FIG> illustrates macrocells <NUM>, <NUM>, and <NUM>, and a small cell <NUM>, each of which may include one or more sectors (not shown). A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In some examples, an unmanned aerial vehicle (UAV) <NUM>, which may be a drone or quadcopter, can be a mobile network node and may be configured to function as a UE. For example, the UAV <NUM> may operate within cell <NUM> by communicating with base station <NUM>.

Within the RAN <NUM>, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each base station <NUM>, <NUM>, <NUM>, and <NUM> may be configured to provide an access point to a core network (e.g., as illustrated in <FIG> and/or <NUM>) for all the UEs in the respective cells. For example, UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM> by way of RRH <NUM>; and UE <NUM> may be in communication with base station <NUM>. In some examples, the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> may be the same as the UE/scheduled entity <NUM> described above and illustrated in <FIG> and/or the UE <NUM> described above and illustrated in <FIG>.

In a further aspect of the RAN <NUM>, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs <NUM> and <NUM>) may communicate with each other using peer to peer (P2P) or sidelink signals <NUM> without relaying that communication through a base station (e.g., base station <NUM>). In a further example, UE <NUM> is illustrated communicating with UEs <NUM> and <NUM>. Here, the UE <NUM> may function as a scheduling entity or a primary sidelink device, and UEs <NUM> and <NUM> may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example, UEs <NUM> and <NUM> may optionally communicate directly with one another in addition to communicating with the scheduling entity <NUM>. Thus, in a wireless communication system with scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

In the radio access network <NUM>, the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network <NUM> in <FIG>), which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In various aspects of the disclosure, a radio access network <NUM> may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE's connection from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, UE <NUM> (illustrated as a vehicle, although any suitable form of UE may be used) may move from the geographic area corresponding to its serving cell <NUM> to the geographic area corresponding to a neighbor cell <NUM>. When the signal strength or quality from the neighbor cell <NUM> exceeds that of its serving cell <NUM> for a given amount of time, the UE <NUM> may transmit a reporting message to its serving base station <NUM> indicating this condition. In response, the UE <NUM> may receive a handover command, and the UE may undergo a handover to the cell <NUM>.

In a network configured for UL-based mobility, UL reference signals from each UE may be utilized by the network to select a serving cell for each UE. In some examples, the base stations <NUM>, <NUM>, and <NUM>/<NUM> may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signals (PSSs), unified Secondary Synchronization Signals (SSSs) and unified Physical Broadcast Channels (PBCH)). The UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may receive the unified synchronization signals, derive the carrier frequency and slot timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal. The uplink pilot signal transmitted by a UE (e.g., UE <NUM>) may be concurrently received by two or more cells (e.g., base stations <NUM> and <NUM>/<NUM>) within the radio access network <NUM>. Each of the cells may measure a strength of the pilot signal, and the radio access network (e.g., one or more of the base stations <NUM> and <NUM>/<NUM> and/or a central node within the core network) may determine a serving cell for the UE <NUM>. As the UE <NUM> moves through the radio access network <NUM>, the network may continue to monitor the uplink pilot signal transmitted by the UE <NUM>. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds that of the signal strength or quality measured by the serving cell, the network <NUM> may handover the UE <NUM> from the serving cell to the neighboring cell, with or without informing the UE <NUM>.

In various implementations, the air interface in the radio access network <NUM> may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum provides for exclusive use of a portion of the spectrum, generally by virtue of a mobile network operator purchasing a license from a government regulatory body. Unlicensed spectrum provides for shared use of a portion of the spectrum without need for a government-granted license. While compliance with some technical rules is generally still required to access unlicensed spectrum, generally, any operator or device may gain access. Shared spectrum may fall between licensed and unlicensed spectrum, wherein technical rules or limitations may be required to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple RATs. For example, the holder of a license for a portion of licensed spectrum may provide licensed shared access (LSA) to share that spectrum with other parties, e.g., with suitable licensee-determined conditions to gain access.

The air interface in the radio access network <NUM> may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or spatial division duplex (SDD). In FDD, transmissions in different directions operate at different carrier frequencies. In SDD, transmissions in different directions on a given channel are separated from one another using spatial division multiplexing.

In some aspects of the disclosure, the scheduling entity and/or scheduled entity may be configured for beamforming and/or multiple-input multiple-output (MIMO) technology. <FIG> illustrates an example of a wireless communication system <NUM> supporting MIMO. In a MIMO system, a transmitter <NUM> includes multiple transmit antennas <NUM> (e.g., N transmit antennas) and a receiver <NUM> includes multiple receive antennas <NUM> (e.g., M receive antennas). Thus, there are N × M signal paths <NUM> from the transmit antennas <NUM> to the receive antennas <NUM>. Each of the transmitter <NUM> and the receiver <NUM> may be implemented, for example, within a scheduling entity <NUM>, a scheduled entity <NUM>, or any other suitable wireless communication device.

The use of such multiple antenna technology enables the wireless communication system to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data, also referred to as layers, simultaneously on the same time-frequency resource. The data streams may be transmitted to a single UE to increase the data rate or to multiple UEs to increase the overall system capacity, the latter being referred to as multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying the data streams with different weighting and phase shifting) and then transmitting each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UE(s) with different spatial signatures, which enables each of the UE(s) to recover the one or more data streams destined for that UE. On the uplink, each UE transmits a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream.

The number of data streams or layers corresponds to the rank of the transmission. In general, the rank of the MIMO system <NUM> is limited by the number of transmit or receive antennas <NUM> or <NUM>, whichever is lower. In addition, the channel conditions at the UE, as well as other considerations, such as the available resources at the base station, may also affect the transmission rank. For example, the rank (and therefore, the number of data streams) assigned to a particular UE on the downlink may be determined based on the rank indicator (RI) transmitted from the UE to the base station. The RI may be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and a measured signal-to-interference-and-noise ratio (SINR) on each of the receive antennas. The RI may indicate, for example, the number of layers that may be supported under the current channel conditions. The base station may use the RI, along with resource information (e.g., the available resources and amount of data to be scheduled for the UE), to assign a transmission rank to the UE.

In Time Division Duplex (TDD) systems, the UL and DL are reciprocal, in that each uses different time slots of the same frequency bandwidth. Therefore, in TDD systems, the base station may assign the rank for DL MIMO transmissions based on UL SINR measurements (e.g., based on a Sounding Reference Signal (SRS) transmitted from the UE or other pilot signal). Based on the assigned rank, the base station may then transmit the CSI-RS with separate C-RS sequences for each layer to provide for multilayer channel estimation. From the CSI-RS, the UE may measure the channel quality across layers and resource blocks and feed back the CQI and RI values to the base station for use in updating the rank and assigning REs for future downlink transmissions.

In the simplest case, as shown in <FIG>, a rank-<NUM> spatial multiplexing transmission on a 2x2 MIMO antenna configuration will transmit one data stream from each transmit antenna <NUM>. Each data stream reaches each receive antenna <NUM> along a different signal path <NUM>. The receiver <NUM> may then reconstruct the data streams using the received signals from each receive antenna <NUM>.

The air interface in the radio access network <NUM> may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, <NUM> NR specifications provide multiple access for UL transmissions from UEs <NUM> and <NUM> to base station <NUM>, and for multiplexing for DL transmissions from base station <NUM> to one or more UEs <NUM> and <NUM>, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP). In addition, for UL transmissions, <NUM> NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), or other suitable multiple access schemes. Further, multiplexing DL transmissions from the base station <NUM> to UEs <NUM> and <NUM> may be provided utilizing time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in <FIG>. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms.

Within the present disclosure, a frame refers to a duration of <NUM> for wireless transmissions, with each frame consisting of <NUM> subframes of <NUM> each. On a given carrier, there may be one set of frames in the UL, and another set of frames in the DL. Referring now to <FIG>, an expanded view of an exemplary DL subframe <NUM> is illustrated, showing an OFDM resource grid <NUM>. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones.

The resource grid <NUM> may be used to schematically represent time-frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids <NUM> may be available for communication. The resource grid <NUM> is divided into multiple resource elements (REs) <NUM>. An RE, which is <NUM> subcarrier × <NUM> symbol, is the smallest discrete part of the time-frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) <NUM>, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include <NUM> subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB <NUM> entirely corresponds to a single direction of communication (either transmission or reception for a given device).

A UE generally utilizes only a subset of the resource grid <NUM>. An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

Each subframe <NUM> (e.g., a <NUM> subframe) may consist of one or multiple adjacent slots. In the example shown in <FIG>, one subframe <NUM> includes four slots <NUM>, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include <NUM> or <NUM> OFDM symbols with a nominal CP. Additional examples may include mini-slots having a shorter duration (e.g., <NUM>, <NUM>, <NUM>, or <NUM> OFDM symbols). These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs.

An expanded view of one of the slots <NUM> illustrates the slot <NUM> including a control region <NUM> and a data region <NUM>. In general, the control region <NUM> may carry control channels (e.g., PDCCH), and the data region <NUM> may carry data channels (e.g., PDSCH or PUSCH). Of course, a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in <FIG> is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region(s) and data region(s).

Although not illustrated in <FIG>, the various REs <NUM> within an RB <NUM> may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs <NUM> within the RB <NUM> may also carry pilots or reference signals. These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB <NUM>.

In a DL transmission, the transmitting device (e.g., the scheduling entity <NUM>) may allocate one or more REs <NUM> (e.g., within a control region <NUM>) to carry DL control information <NUM> including one or more DL control channels that generally carry information originating from higher layers, such as a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), etc., to one or more scheduled entities <NUM>. In addition, DL REs may be allocated to carry DL physical signals that generally do not carry information originating from higher layers. These DL physical signals may include a primary synchronization signal (PSS); a secondary synchronization signal (SSS); demodulation reference signals (DM-RS); phase-tracking reference signals (PT-RS); channel-state information reference signals (CSI-RS); etc..

The synchronization signals PSS and SSS (collectively referred to as SS), and in some examples, the PBCH, may be transmitted in an SS block that includes <NUM> consecutive OFDM symbols, numbered via a time index in increasing order from <NUM> to <NUM>. In the frequency domain, the SS block may extend over <NUM> contiguous subcarriers, with the subcarriers being numbered via a frequency index in increasing order from <NUM> to <NUM>. Of course, the present disclosure is not limited to this specific SS block configuration. Other non-limiting examples may utilize greater or fewer than two synchronization signals; may include one or more supplemental channels in addition to the PBCH; may omit a PBCH; and/or may utilize nonconsecutive symbols for an SS block, within the scope of the present disclosure.

The PDCCH may carry downlink control information (DCI) for one or more UEs in a cell. This can include, but is not limited to, power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions.

In an UL transmission, a transmitting device (e.g., a scheduled entity <NUM>) may utilize one or more REs <NUM> to carry UL control information <NUM> (UCI). The UCI can originate from higher layers via one or more UL control channels, such as a physical uplink control channel (PUCCH), a physical random access channel (PRACH), etc., to the scheduling entity <NUM>. Further, UL REs may carry UL physical signals that generally do not carry information originating from higher layers, such as demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), sounding reference signals (SRS), etc. In some examples, the control information <NUM> may include a scheduling request (SR), i.e., a request for the scheduling entity <NUM> to schedule uplink transmissions. Here, in response to the SR transmitted on the control channel <NUM>, the scheduling entity <NUM> may transmit downlink control information <NUM> that may schedule resources for uplink packet transmissions.

UL control information may also include hybrid automatic repeat request (HARQ) feedback such as an acknowledgment (ACK) or negative acknowledgment (NACK), channel state information (CSI), or any other suitable UL control information. HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc..

In addition to control information, one or more REs <NUM> (e.g., within the data region <NUM>) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH); or for an UL transmission, a physical uplink shared channel (PUSCH).

In order for a UE to gain initial access to a cell, the RAN may provide system information (SI) characterizing the cell. This system information may be provided utilizing minimum system information (MSI), and other system information (OSI). The MSI may be periodically broadcast over the cell to provide the most basic information required for initial cell access, and for acquiring any OSI that may be broadcast periodically or sent on-demand. In some examples, the MSI may be provided over two different downlink channels. For example, the PBCH may carry a master information block (MIB), and the PDSCH may carry a system information block type <NUM> (SIB1). In the art, SIB1 may be referred to as the remaining minimum system information (RMSI).

OSI may include any SI that is not broadcast in the MSI. In some examples, the PDSCH may carry a plurality of SIBs, not limited to SIB1, discussed above. Here, the OSI may be provided in these SIBs, e.g., SIB2 and above.

The channels or carriers described above and illustrated in <FIG> and <FIG> are not necessarily all the channels or carriers that may be utilized between a scheduling entity <NUM> and scheduled entities <NUM>, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

<FIG> illustrates example applications of timing advance offsets at a first UE (UE1) and a second UE (UE2). A timing advance offset (also referred to as a timing advance (TA)) may be applied at a UE to ensure that the downlink and uplink subframes are synchronized at a base station (BS). In the example of <FIG>, the UE1 may be located far from the BS and UE2 may be located close to the BS. The UE1 may experience a first propagation delay δ<NUM> <NUM> on the downlink and the UE2 may experience a second propagation delay δ<NUM> <NUM> on the downlink. Since UE1 is located far from the BS as compared to UE2, it may be assumed that δ<NUM> > δ<NUM>. Therefore, when the BS transmits subframe #n (e.g., subframe #n <NUM>-<NUM>) at time t1 <NUM>, the UE1 may receive the subframe #n (e.g., subframe #n <NUM>-<NUM>) at time t1+δ<NUM>. The UE2 may receive the subframe #n (e.g., subframe #n <NUM>-<NUM>) at time t1+δ<NUM>. Both UE1 and UE2 take the downlink subframe arrival (together with Timing Advance) as a reference to calculate uplink subframe timing.

The timing advance is equal to twice the propagation delay assuming that the same propagation delay value applies to both downlink and uplink directions. Therefore, UE1 may need to start it's uplink (e.g., uplink subframe <NUM>-<NUM>) at t2 +2δ<NUM> (where t2 is the downlink reception time for UE1), whereas UE2 may need to start it's uplink (e.g., uplink subframe <NUM>-<NUM>) at t3+2δ<NUM> (where t3 is the downlink reception time for UE2) to ensure that both of the uplink transmissions (from UE1 and UE2) reach the BS at the same time (e.g., uplink subframes <NUM>-<NUM>, <NUM>-<NUM>). Accordingly, this means that both uplink and downlink subframes are time aligned.

If the timing advance is not applied, then the start of uplink transmission from UE2 for subframe #n+<NUM> may overlap with the end of uplink transmission from UE1 for subframe #n. Assuming that same resource blocks are assigned to UE1 in subframe #n and UE2 in subframe #n+<NUM>, this overlap may create interference which causes reception failures at the BS. If a proper value of timing advance is applied, collisions of these subframes may be avoided.

<FIG> is a diagram illustrating an example <NUM> of full duplex (FD) communication. The example <NUM> of <FIG> includes a UE <NUM> and transmission and reception points (e.g., TRPs) <NUM>, <NUM>, where the UE <NUM> is sending UL transmissions (e.g., UL transmission <NUM>) to TRP-<NUM><NUM> and is receiving DL transmissions (e.g., DL transmission <NUM>) from TRP-<NUM><NUM>. In the example <NUM> of <FIG>, FD is enabled for the UE <NUM>, but not for the TRPs <NUM>, <NUM>.

The present disclosure relates to improving the manner in which flexible TDD operates to allow for FD communication, simultaneous UL/DL transmission (e.g., in frequency range <NUM> (FR2)). Flexible TDD capability may be present at either a base station or UE, or both. For example, for a UE, UL transmission may be from one antenna panel and DL reception may be in another antenna panel. FD communication may be conditional on a beam separation of the UL beam and DL beam at the respective antenna panels. As such, improving the manner in which the selection of the UL beam and DL beam for FD communication is desirable. Utilizing FD communication may provide a reduction in latency, such that it may be possible to receive a DL signal in UL only slots, which may enable latency savings. In addition, FD communication may enhance spectrum efficiency per cell or per UE, and may allow for a more efficient utilization of resources.

The present disclosure further relates to improving timing alignment of DL and UL signals at a UE when operating in a full duplex mode, as well as improving timing alignment of DL and UL signals at both a UE and a base station (e.g., TRP) with respect to full duplex transmissions.

<FIG> illustrates a procedure for determining a reception timing difference between a reception time of a DL signal at a receive (Rx) beam of a UE and a reception time of a UL signal at the receive (Rx) beam of the UE, where the UL signal is transmitted from a transmit (Tx) beam of the UE. As shown in <FIG>, the UE <NUM> may transmit a physical random access channel (PRACH) message <NUM> to the TRP-<NUM><NUM> from a first beam <NUM>. The UE <NUM> may then receive a random access response (RAR) message <NUM> at the first beam <NUM> from the TRP-<NUM><NUM>. In some examples, the RAR message <NUM> may include a timing advance (TA) command. The TA command may include a timing advance to be applied by the UE <NUM> for uplink transmissions. The TRP-<NUM><NUM> may then schedule Layer <NUM> Signal to Interference plus Noise Ratio (L1-SINR) measurements for the UE <NUM> via a configuration information message <NUM>, where the L1-SINR measurements includes self-interference measurements (SIM) and DL and UL reception timing measurements for the UE <NUM>. In some examples, as explained in detail herein, resources used for the self-interference measurements (SIM) may be used for the reception timing measurements, which may reduce signaling overhead.

In some aspects of the disclosure, the UE <NUM> may perform the L1-SINR measurements including the self-interference measurements (SIM) and DL and UL reception timing measurements by performing one or more DL/Rx and UL/Tx beam sweep operations. For example, as shown in <FIG>, the UE <NUM> may have multiple transmit (Tx) beams (e.g., Tx beams <NUM>, <NUM>) and multiple receive (Rx) beams (e.g., Rx beams <NUM>, <NUM>). The UE <NUM> may perform a first beam sweep operation by transmitting a UL signal (e.g., a sounding reference signal (SRS)) from the Tx beam <NUM>, and determining both the reception timing of the UL signal and the self-interference due to the UL signal at each of the Rx beams <NUM> and <NUM>. The UE <NUM> may perform a second beam sweep operation by transmitting a UL signal (e.g., a sounding reference signal (SRS)) from the Tx beam <NUM>, and determining both the reception timing of the UL signal and the self-interference due to the UL signal at each of the Rx beams <NUM> and <NUM>. In some examples, the UE <NUM> may transmit each UL signal during a beam sweep operation by applying the timing advance received in the RAR message <NUM>.

In some aspects of the disclosure, the UE <NUM> may determine a reception timing of a DL signal from the TRP-<NUM><NUM> for each Rx beam. For example, the UE <NUM> may determine a reception timing of the DL signal <NUM> received at Rx beam <NUM> and may determine a reception timing of the DL signal <NUM> received at Rx beam <NUM>. For example, the DL signals <NUM>, <NUM> may be CSI-RS signals.

In the example of <FIG>, the two Tx beams <NUM>, <NUM> and the two Rx beams <NUM>, <NUM> may form four beam pairs for FD communication at the UE. For example, the Tx beam <NUM> and the Rx beam <NUM> may form a first beam pair, the Tx beam <NUM> and the Rx beam <NUM> may form a second beam pair, the Tx beam <NUM> and the Rx beam <NUM> may form a third beam pair, and the Tx beam <NUM> and the Rx beam <NUM> may form a fourth beam pair.

<FIG> is a diagram <NUM> illustrating a beam measurement process in accordance with various aspects of the present disclosure. The diagram <NUM> of <FIG> includes a base station (BS) <NUM>, and a UE comprising multiple UE panels (e.g., UE panel-<NUM><NUM>, UE panel-<NUM><NUM>, UE panel-<NUM><NUM>). The BS <NUM> and UE may be configured to select CSI-RS beams based on a beam measurement procedure (e.g., <NUM>). The beam measurement procedure <NUM> may allow for the UE panels (e.g., <NUM>, <NUM>, <NUM>) to measure CSI-RS signals from the BS <NUM> to determine which of the Rx beams are the best at the UE side. The determination of the best Rx beams may be based on the DL signal strength measured at the UE panels. Each Rx beam may be associated with a Tx CSI-RS beam at the BS <NUM>. The beam measurement procedure <NUM> may allow for the BS <NUM> to transmit multiple CSI-RS resources to the UE panels in order to measure the DL channel quality or signal strength at the UE side. The UE may send a CSI-RS report to the BS <NUM> indicating the top Tx beams at the BS <NUM> with each associated top Rx beam at the UE side. The top Rx beams may be assumed to be the top Tx beams at the UE panels based on channel reciprocity. In some aspects, the UE may report the top four Tx beams. However, in some aspects, the UE may report more or less than the top four Tx beams. Upon the determination of the top four Tx beams with its associated top Rx beams at the UE, the UE may perform a self-interference measurement (SIM). The UE may also report the top four beams each with an associated panel ID of the UE, so that gNB can avoid configuring intra-panel SIM to save resource overhead.

To perform the SIM, the UE may transmit a transmission from the beam <NUM> with repetition (e.g. three times) from UE panel-<NUM><NUM>, such that beams <NUM>, <NUM>, and <NUM> may measure the amount of energy they receive from the transmission of the beam <NUM>. The transmission from the beam <NUM> may be an uplink transmission to the BS <NUM>, however, during the uplink transmission from beam <NUM> to the BS <NUM>, some energy may be received at the beams of the other panels. Such energy may be due to side lobes or based on the configuration of the other panels. As such, the beams <NUM>, <NUM>, and <NUM> may measure the amount of self-interference caused by the transmission from the beam <NUM>. This process repeats for all of the top four beams indicated in the CSI-RS report. For example, beam <NUM> may send a transmission with repetition (e.g. three times) such that beams <NUM>, <NUM>, and <NUM> measure the amount of self-interference caused by the transmission from beam <NUM>. Upon the completion of the self-interference procedure and the channel measurement procedure, an indication <NUM> may be sent to the BS <NUM> indicating the top DL and UL beam pairs of the UE in a L1-SINR report via either the actual value or a largest value plus differential value of SINR. The DL and UL beams pairs selected as the top DL and UL beam pairs are beams that have passed a threshold for selection. In some aspects, the UE may report that no beams pass the threshold, such that no feasible beam and/or beam pair is present.

To perform the self-interference, a modified Layer <NUM> Signal to Interference plus Noise Ratio (L1-SINR) configuration and procedure may be utilized. L1-SINR may include two resource settings, the first resource setting which may be provided by the higher layer parameter "resourcesForChannelMeasurement" is configured to perform channel measurement (CM) via CSI-RS. The CM may measure the channel quality. The second resource which may be provided by either higher layer parameter "csi-IM-ResourcesForInterference" or the higher layer parameter "nzp-CSI-RS-ResourcesForInterference" and is configured to perform interference measurement (IM) via CSI-RS. The modified L1-SINR may be configured to utilize SRS, instead of CSI-RS, to perform the interference measurement (IM) procedure (e.g., for purposes of measuring self-interference at the UE). Each CSI-RS resource serving as a channel measurement resource (CMR) may be associated with one SRS resource serving as an interference measurement resource (IMR). The number of CSI-RS resources for CM may be equal to the number of SRS resources for interference measurement (IM). The CMR may also be re-used for the original L1-SINR beam management purposes. In addition, the IMR may also be reused for cross link interference (CLI) measurement purposes concurrently to measure the cross link interference at neighbor UEs using the same SRS resources used for SIM. In some aspects, the IMR configuration may be configured to define a full or reduced Tx power. For example, the reduced Tx power may be based on X dBm or X% of the full Tx power. The UE may use the configuration to scale up the calculated SINR accordingly.

With reference back to <FIG>, the diagram <NUM> provides an example of the CM and IM using the modified L1-SINR configuration and procedure. The CM portion includes four CMRs <NUM>, <NUM>, <NUM>, <NUM> such that the BS <NUM> is configured to transmit a CSI-RS to each of the top four Rx beams of the UE. For example, CMR <NUM> may be transmitted to Rx beam <NUM> of UE panel-<NUM><NUM>, CMR <NUM> may be transmitted to Rx beam <NUM> of UE panel- <NUM><NUM>, CMR <NUM> may be transmitted to Rx beam <NUM> of UE panel-<NUM><NUM>, and CMR <NUM> may be transmitted to Rx beam <NUM> of UE panel-<NUM><NUM>. The UE may measure the channel quality received at the UE by the corresponding Rx beams. The UE may store the channel quality measurements under the CMR to determine the SINR.

The IM portion includes the same or more amount of resources as in the CM portion, such that the CMRs are mapped to a corresponding IMR. For example, each CMR is associated with an IMR for the interference measurement. Each CMR can also be mapped to multiple IMRs for measuring the interference to the same Rx beam as the CMR but transmitting from different beams of different panels of the UE. The IM portion includes four IMRs <NUM>, <NUM>, <NUM>, <NUM> and are mapped to a corresponding CMR. For example, CMR <NUM> may be mapped to IMR <NUM>, CMR <NUM> may be mapped to IMR <NUM>, CMR <NUM> may be mapped to IMR <NUM>, and CMR <NUM> may be mapped to IMR <NUM>. The IM portion allows for SIM to be performed. To perform SIM, the IMRs configure the UE with SRS resources. Each of the beams (e.g., <NUM>, <NUM>, <NUM>, <NUM>) may be configured to transmit an SRS when sending the uplink transmission for the SIM. The transmitted SRS may be utilized to measure SIM. In some aspects, the UE panel-<NUM><NUM> may transmit the SRS at beam <NUM>, such that beams <NUM>, <NUM>, and <NUM> may measure the amount of self-interference that is caused by the transmission from the beam <NUM>. This process repeats for all the other beams <NUM>, <NUM>, <NUM>. For example, beam <NUM> may send a transmission such that beams <NUM>, <NUM>, and <NUM> measure the amount of self-interference caused by the transmission from beam <NUM>. Upon the completion of the CM and the SIM, an SINR may be determined.

The mapping of the CMRs and the IMRs allows for an SINR to be calculated based on the results of the CM and IM portions. The SINR may be determined based on a ratio of the CMR and the corresponding IMR, as shown in the table of <FIG>.

The aspect of <FIG> provides an example of CM and IM resources being TDM, such that the CM portion and the IM portion occur at different times. In some aspects, a DL timing may be utilized for the CM, while a UL timing may be utilized for the IM. In such instances, the SINR may be calculated based on a ratio of CM and IM and noise (e.g., CM/(IM + noise)). Upon the calculations of the SINR, the UE may report the SINR results to the BS <NUM>. The SINR results may include a report of the top SINR DL and UL beam pairs.

In the aspects described herein, the modified Layer <NUM> Signal to Interference plus Noise Ratio (L1-SINR) configuration may include a respective measurement gap between each of the self-interference measurements. In some aspects, the modified L1-SINR configuration information may further indicate an initial measurement gap between a channel measurement and one of the self-interference measurements. For example, as shown in <FIG>, the BS <NUM> may configure an initial measurement gap <NUM> between a last CSI-RS transmission of CMR <NUM> and a first SRS transmission (e.g., from beam <NUM>) of IMR <NUM>. In this example, the BS <NUM> may further configure measurement gaps <NUM>, <NUM> between each respective SRS transmission (e.g., from beams <NUM>, <NUM>) of IMR <NUM>.

Each measurement gap may enable the UE to measure the reception time of an uplink transmission (e.g., an SRS) at a receive (Rx) beam of the UE when performing the SIM. For example, the measurement gap <NUM> may enable the UE to measure the reception time (at Rx beam <NUM>) of the uplink transmission from the transmit (Tx) beam <NUM>, the measurement gap <NUM> may enable the UE to measure the reception time (at Rx beam <NUM>) of the uplink transmission from the transmit (Tx) beam <NUM>, and the measurement gap <NUM> may enable the UE to measure the reception time (at Rx beam <NUM>) of the uplink transmission from the transmit (Tx) beam <NUM>. In some aspects of the disclosure, each measurement gap may further serve as a beam switching period.

In some aspects of the disclosure, the BS <NUM> may configure the duration of each measurement gap. In some examples, and as shown in <FIG>, each measurement gap may be configured to have a duration of one orthogonal frequency-division multiplexing (OFDM) symbol. For example, the measurement gap <NUM> may be configured as the symbol n+<NUM>, the measurement gap <NUM> may be configured as the symbol n+<NUM>, and the measurement gap <NUM> may be configured as the symbol n+<NUM>. In other examples, each measurement gap may be configured to have a duration of multiple OFDM symbols. In some aspects of the disclosure, the BS <NUM> may configure two or more of the measurement gaps to have different durations. For example, the BS <NUM> may indicate the duration of the measurement gaps (e.g., measurement gaps <NUM>, <NUM>, <NUM>) via a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or in downlink control information (DCI). Although the example of <FIG> depicts the measurement gaps <NUM>, <NUM>, <NUM> for IMR <NUM>, it should be understood that measurement gaps may also be configured for the remaining IMRs <NUM>, <NUM>, <NUM> (not shown for ease of illustration).

In some aspects of the disclosure, the UE may use a measured reception time of an uplink transmission (e.g., an SRS from a transmit (Tx) beam of the UE when performing the SIM) at a receive (Rx) beam of the UE to determine a reception timing difference between a DL signal and a UL signal for a given pair of Tx/Rx beams at the UE. For example, with reference to the example beam sweep operation for SIM shown in <FIG>, the UE <NUM> may select a receive (Rx) beam <NUM> and first and second transmit (Tx) beams <NUM>, <NUM>. The UE <NUM> may receive a DL signal <NUM> from the TRP-<NUM><NUM> at the Rx beam <NUM> and may determine a reception time of the DL signal <NUM>. The UE <NUM> may then transmit a first UL signal <NUM> via the first Tx beam <NUM>. As shown in <FIG>, at least some of the energy of the first UL signal <NUM> (e.g., shown as the dashed line <NUM>) may be directed back to Rx beam <NUM> via a first reflector <NUM>. Therefore, the dashed line <NUM> in <FIG> may represent a self-interference signal from the transmission of the UL signal <NUM>. The UE <NUM> may measure the reception time of the first UL signal <NUM> (e.g., self-interference signal <NUM>) received at the Rx beam <NUM>.

As further shown in <FIG>, the UE <NUM> may transmit a second UL signal <NUM> via the second Tx beam <NUM>. As shown in <FIG>, at least some of the energy of the second UL signal <NUM> (e.g., shown as the dashed line <NUM>) may be directed back to Rx beam <NUM> via a second reflector <NUM>. Therefore, the dashed line <NUM> in <FIG> may represent a self-interference signal from the transmission of the UL signal <NUM>. The UE <NUM> may measure the reception time of the second UL signal <NUM> (e.g., self-interference signal <NUM>) received at the Rx beam <NUM>. In some examples, the UE <NUM> may transmit the UL signals <NUM>, <NUM> by applying a timing advance received from the TRP-<NUM><NUM>.

<FIG> shows a diagram <NUM> illustrating an example timing of DL and UL signals between the UE <NUM> and the TRP-<NUM><NUM> and a diagram <NUM> illustrating an example timing of DL and UL signals between the UE <NUM> and the TRP-<NUM><NUM>. With reference to <FIG> and the diagram <NUM> in <FIG>, the TRP-<NUM><NUM> may transmit a DL signal <NUM>-<NUM> in symbol #n at a first reference time (tRef_1) <NUM>. The UE <NUM> may receive the DL signal (shown as DL signal <NUM>-<NUM> in <FIG>) at a receive (Rx) beam at time t3 <NUM>. The period between the time tRef_1 <NUM> and time t3 <NUM> is shown as the duration b1 <NUM>. The duration b1 <NUM> may be considered to be the propagation delay between the TRP-<NUM><NUM> and the UE <NUM>.

As further shown in <FIG>, the UE <NUM> may transmit a UL signal <NUM>-<NUM> (with a timing advance (TA) received from the TRP-<NUM><NUM>) in a transmit (Tx) beam in symbol #n at a time t1. The period between the time t1 <NUM> and tRef_1 <NUM> is shown as the duration a1 <NUM>. In the example of <FIG>, the duration a1 <NUM> may be approximately equal to the duration b1 <NUM>, such that the timing advance applied to the transmission of the UL signal <NUM>-<NUM> is the sum of a1 <NUM> and b1 <NUM> (e.g., TATRP-<NUM> = a1 + b1). The TRP-<NUM><NUM> may receive the UL signal (shown as UL signal <NUM>-<NUM> in <FIG>) at the time tRef_1 <NUM>. In the example of <FIG>, the Rx beam may also receive the UL signal (shown as UL signal <NUM>-<NUM> in <FIG>) at time t2 <NUM>. The UL signal <NUM>-<NUM> may be considered a self-interference signal. The period between the time t2 <NUM> and tRef_1 <NUM> is shown as the duration c1 <NUM>.

With reference to <FIG> and the diagram <NUM> in <FIG>, the TRP-<NUM><NUM> may transmit a DL signal <NUM>-<NUM> in symbol #n at a second reference time (tRef_2) <NUM>. The UE <NUM> may receive the DL signal (shown as DL signal <NUM>-<NUM> in <FIG>) at the receive (Rx) beam at time t6 <NUM>. The period between the time tRef_2 <NUM> and time t6 <NUM> is shown as the duration b2 <NUM>. The duration b1 <NUM> may be considered to be the propagation delay between the TRP-<NUM><NUM> and the UE <NUM>.

As further shown in <FIG>, the UE <NUM> may transmit a UL signal <NUM>-<NUM> (with a timing advance) in the transmit (Tx) beam in symbol #n at a time t4. The period between the time t4 <NUM> and tRef_2 <NUM> is shown as the duration a2 <NUM>. In the example of <FIG>, the duration a2 <NUM> may be approximately equal to the duration b2 <NUM>, such that the timing advance applied to the transmission of the UL signal <NUM>-<NUM> is the sum of a2 <NUM> and b2 <NUM> (e.g., TATRP-<NUM> = a2 + b2). The TRP-<NUM><NUM> may receive the UL signal (shown as UL signal <NUM>-<NUM> in <FIG>) at the time tRef_2 <NUM>. In the example of <FIG>, the Rx beam may also receive the UL signal (shown as UL signal <NUM>-<NUM> in <FIG>) at time t5 <NUM>. The UL signal <NUM>-<NUM> may be considered a self-interference signal. The period between the time t5 <NUM> and tRef_2 <NUM> is shown as the duration c2 <NUM>.

Therefore, if a certain Tx beam is used for transmitting UL signals to the TRP-<NUM><NUM> and a certain Rx beam is used for receiving DL signals from the TRP-<NUM><NUM> in a full duplex mode, the reception timing difference between a DL and UL signal for a pair of Tx/Rx beams may be expressed as the sum of the durations c1 <NUM> and b2 <NUM>. Alternatively stated, the reception timing difference between a DL and UL signal for a pair of Tx/Rx beams may be defined as the difference between the reception time (e.g., t6 <NUM>) of the DL signal <NUM>-<NUM> received at the Rx beam and the reception time (e.g., t2 <NUM>) of the UL signal <NUM>-<NUM> received at the Rx beam. In some examples, tRef_1 <NUM> and tRef_2 <NUM> may each represent a time zero from the perspective of the respective TRPs <NUM>, <NUM>.

In some aspects of the disclosure, the UE <NUM> may select a pair of Tx/Rx beams at the UE for full duplex communication if the reception timing difference between a DL signal and a UL signal at the UE is below a threshold. In some examples, the threshold may be set to a cyclic prefix duration.

With the timing aligned for UL and DL signals, structured DL and UL transmissions may avoid signal leakage into sub-bands, partially overlapped FDMed full duplex bands, and orthogonal UL and DL demodulation reference signals (DMRSs). Moreover, for a UE transmitting different reference signals (e.g., CSI-RS and SRS) using FDM, the previously described time alignment of UL and DL signals may avoid signal leakage may into other frequency bands.

<FIG> illustrates an example procedure <NUM> for measuring different reception timing differences for different pairs of Tx/Rx beams at a UE (e.g., UE <NUM>). In one example scenario, with reference to <FIG>, the UE <NUM> may select the receive (Rx) beam <NUM> for receiving DL signals from the TRP-<NUM><NUM> in full duplex mode. The UE <NUM> may then perform a beam sweep operation using one or more Tx beams (e.g., Tx beams <NUM>, <NUM>) by transmitting UL signals (e.g., SRS) from the Tx beams at designated times, such as the measurement gaps described herein.

As shown in <FIG>, the TRP-<NUM><NUM> and/or TRP-<NUM><NUM> may configure a respective measurement gap between UL transmissions (e.g., SRS transmissions) for SIM, such as the gap symbol #n-<NUM> and the gap symbol #n+<NUM>. Accordingly, with reference to <FIG> and <FIG>, the UE <NUM> may transmit the first UL signal <NUM> from the first Tx beam <NUM> for a symbol #n (e.g., UL symbol #n <NUM>-<NUM>) during a measurement gap. The measurement gap may be the gap symbol #n-<NUM> shown in <FIG>. In <FIG>, it should be noted that the UE <NUM> transmits the first UL signal <NUM> at time t1 <NUM> with a timing advance <NUM> expressed as a1 + b2. For example, a1 may be the duration a1 <NUM> shown in <FIG> and b2 may be the duration b2 <NUM> shown in <FIG>. For example, the timing advance <NUM> may include the duration b2 <NUM> to achieve alignment with the reference time established for the DL Rx beam <NUM> (e.g., the time t6 <NUM> at which a DL signal is received at the UE <NUM> from the TRP-<NUM><NUM> via the Rx beam <NUM>).

In the example of <FIG>, the UE <NUM> may measure the reception time (e.g., t2 <NUM>) of the first UL signal <NUM> (e.g., self-interference signal <NUM>) received at the Rx beam <NUM>. The UE <NUM> may determine the period between the time t2 <NUM> and tRef_1 <NUM>, which is shown as the duration <NUM> (e.g., c1_1 + b2). The duration <NUM> may represent the reception timing difference between a UL signal from the first Tx beam <NUM> and a DL signal at the Rx beam <NUM>. In some aspects, the gap symbol #n-<NUM> enables the UE <NUM> to more accurately measure the time t2 <NUM> at the Rx beam <NUM> since no DL signals may interfere with the UL signal transmitted during the gap symbol #n-<NUM>.

As further shown in <FIG>, the UE <NUM> may transmit the second UL signal <NUM> from the second Tx beam <NUM> for a symbol #n+<NUM> (e.g., UL symbol #n+<NUM><NUM>-<NUM>) during a measurement gap. The measurement gap may be the gap symbol #n+<NUM> shown in <FIG>. In <FIG>, it should be noted that the UE <NUM> transmits the second UL signal <NUM> at time t3 <NUM> with a timing advance <NUM> expressed as a1 + b2, which may be the same as the timing advance <NUM>.

In the example of <FIG>, the UE <NUM> may measure the reception time (e.g., t4 <NUM>) of the second UL signal <NUM> (e.g., self-interference signal <NUM>) received at the Rx beam <NUM>. The UE <NUM> may determine the period between the time t4 <NUM> and tRef_ <NUM><NUM>, which is shown as the duration <NUM> (e.g., c1_2 +b2). The duration <NUM> may represent the reception timing difference between a UL signal from the second Tx beam <NUM> and a DL signal at the Rx beam <NUM>. In some aspects, the gap symbol #n+<NUM> enables the UE <NUM> to more accurately measure the time t4 <NUM> at the Rx beam <NUM> since no DL signals may interfere with the UL signal transmitted during the gap symbol #n+<NUM>.

In the example scenario described with references to <FIG> and <FIG>, the duration <NUM> (e.g., c1_1 + b2) may be less that the duration <NUM> (e.g., c1_2 + b2). This is because the first reflector <NUM> is situated farther away from the UE <NUM> than the second reflector <NUM>, thereby causing a larger propagation delay in the UL signal transmissions arriving at the Rx beam <NUM>. Therefore, the duration c1_1 resulting from the farther reflector (e.g., the first reflector <NUM>) may be larger than the duration c1_2 resulting from the closer reflector (e.g., the second reflector <NUM>). Therefore, in some examples, since the reception timing difference (e.g., c1_1 + b2 <NUM>) between the Tx/Rx beams <NUM>, <NUM> may be less than the reception timing difference (e.g., c1_2 + b2 <NUM>) between the Tx/Rx beams <NUM>, <NUM>, the Tx/Rx beams <NUM>, <NUM> may experience less self-interference and may provide better performance during full duplex communication.

In some aspects of the disclosure, the UE <NUM> may compare the respective reception timing differences for the pairs of Tx/Rx beams (e.g., Tx/Rx beams <NUM>, <NUM>, Tx/Rx beams <NUM>, <NUM>) to a threshold value and may identify the pairs of Tx/Rx beams having reception timing differences that are below the threshold value. In some examples, the threshold value may be a cyclic prefix duration.

In some aspects of the disclosure, the UE <NUM> can estimate a reception timing difference for a Tx/Rx beam pair at the UE with respect to an uplink base station and a downlink base station according to the expression Trx_dl_i_m - Trx_ul_j_n and may estimate whether Trx_dl_i_m - Trx_ul_j_n is less than a threshold (e.g., a cyclic prefix duration). For example, the term Trx_dl_i_m may represent the reception time (e.g., at the UE <NUM>) of a DL signal transmitted from a downlink base station (e.g., a downlink transmission point) having an index i via a beam m on that downlink base station, and the term Trx_ul_j_n may represent the reception time (e.g., at the UE <NUM>) of a UL signal transmitted to an uplink base station (e.g., an uplink transmission point) having an index j via a beam n on that uplink base station.

<FIG> is a block diagram illustrating an example of a hardware implementation for a user equipment (UE) <NUM> employing a processing system <NUM>. For example, the UE <NUM> may correspond to any of the UEs shown and described above in reference to <FIG>.

The UE <NUM> may be implemented with a processing system <NUM> that includes one or more processors <NUM>. Examples of processors <NUM> include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the UE <NUM> may be configured to perform any one or more of the functions described herein. That is, the processor <NUM>, as utilized in the UE <NUM>, may be used to implement any one or more of the processes and procedures described below and illustrated in <FIG>.

In this example, the processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors (represented generally by the processor <NUM>), a memory <NUM>, and computer-readable media (represented generally by the computer-readable medium <NUM>). The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

A bus interface <NUM> provides an interface between the bus <NUM> and a transceiver <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium (e.g., air interface). Depending upon the nature of the apparatus, a user interface <NUM> (e.g., keypad, display, touch screen, speaker, microphone, control knobs, etc.) may also be provided. Of course, such a user interface <NUM> is optional, and may be omitted in some examples.

The computer-readable medium <NUM> may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium <NUM> may reside in the processing system <NUM>, external to the processing system <NUM>, or distributed across multiple entities including the processing system <NUM>. The computer-readable medium <NUM> may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. In some examples, the computer-readable medium <NUM> may be part of the memory <NUM>. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In some aspects of the disclosure, the processor <NUM> may include circuitry configured for various functions. For example, the processor <NUM> may include configuration information reception circuitry <NUM> configured to receive, from a base station, configuration information for performing beam pair selection measurements with respect to a subset of candidate beams (e.g., beams <NUM>, <NUM>, <NUM>, <NUM> and/or beams <NUM>, <NUM>, <NUM>) at the UE. In some aspects, the subset of candidate beams may be the top candidate beams used for the sweeping through SRS. For example, the UE may determine the top candidate beams by performing a channel measurement process on the candidate beams.

The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements.

The processor <NUM> may further include beam pair selection measurement performance circuitry <NUM> configured to perform the beam pair selection measurements based on the configuration information.

The processor <NUM> may further include beam pair selection circuitry <NUM> configured to select at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements.

The processor <NUM> may further include report transmission circuitry <NUM> configured to transmit a report including the selected at least one pair of Tx/Rx beams to the base station.

In one or more examples, the computer-readable storage medium <NUM> may include configuration information reception software <NUM> configured to receive, from a base station, configuration information for performing beam pair selection measurements with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements. For example, the configuration information reception software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

In one or more examples, the computer-readable storage medium <NUM> may further include beam pair selection measurement performance software <NUM> configured to perform the beam pair selection measurements based on the configuration information. For example, the beam pair selection measurement performance software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

In one or more examples, the computer-readable storage medium <NUM> may further include beam pair selection software <NUM> configured to select at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements. For example, the beam pair selection software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

In one or more examples, the computer-readable storage medium <NUM> may further include report transmission software <NUM> configured to transmit a report including the selected at least one pair of Tx/Rx beams to the base station. For example, the report transmission software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

<FIG> is a conceptual diagram illustrating an example of a hardware implementation for an exemplary base station <NUM> employing a processing system <NUM>. For example, the base station <NUM> may be the TRP-<NUM><NUM>, the TRP-<NUM><NUM>, or the base station <NUM> as illustrated in <FIG>.

In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system <NUM> that includes one or more processors <NUM>. That is, the processor <NUM>, as utilized in the base station <NUM>, may be used to implement any one or more of the processes described below. The processing system <NUM> may be substantially the same as the processing system <NUM> illustrated in <FIG>, including a bus interface <NUM>, a bus <NUM>, memory <NUM>, a processor <NUM>, a computer-readable medium <NUM>, and a transceiver <NUM>.

In some aspects of the disclosure, the processor <NUM> may include circuitry configured for various functions. For example, the processor <NUM> may include configuration information transmission circuitry <NUM> configured to transmit, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements.

The processor <NUM> may further include report reception circuitry <NUM> configured to receive, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements.

In one or more examples, the computer-readable storage medium <NUM> may include configuration information transmission software <NUM> configured to transmit, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements. For example, the configuration information transmission software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

In one or more examples, the computer-readable storage medium <NUM> may further include report reception software <NUM> configured to receive, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements. For example, the report reception software <NUM> may be configured to implement one or more of the functions described below in relation to <FIG>, including, e.g., block <NUM>.

<FIG> is a flow chart <NUM> of a method for wireless communication at a UE in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all aspects. In some examples, the process <NUM> may be carried out by the UE <NUM> illustrated in <FIG>, <FIG> and <FIG>. In some examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, the UE receives, from a base station, configuration information (e.g., configuration information message <NUM>) for performing beam pair selection measurements with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams (e.g., the SRS transmissions from Tx beams <NUM>, <NUM>, <NUM> to Rx beam <NUM> as shown in <FIG>). The configuration information indicates measurement gaps (e.g., measurement gaps <NUM>, <NUM>) between the self-interference measurements. For example, the configuration information reception circuitry <NUM>, together with the transceiver <NUM>, shown and described above in connection with <FIG> may receive, from a base station, the configuration information for performing beam pair selection measurements with respect to a subset of candidate beams at the UE.

At block <NUM>, the UE performs the beam pair selection measurements based on the configuration information. For example, the beam pair selection measurements may include the beam sweep operation for SIM described with reference to <FIG>. In some aspects of the disclosure, the UE performs the beam pair selection measurements by determining a respective reception timing difference between a downlink (DL) signal and an uplink (UL) signal for each of one or more pairs of Tx/Rx beams from the subset of candidate beams. One example of a reception timing difference may be the previously described sum of the durations c1 <NUM> and b2 <NUM> in <FIG>. For example, the beam pair selection measurement performance circuitry <NUM>, together with the transceiver <NUM>, shown and described above in connection with <FIG> may perform the beam pair selection measurements based on the configuration information.

At block <NUM>, the UE selects at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements. In some aspects of the disclosure, the UE selects the at least one pair of Tx/Rx beams by comparing the respective reception timing difference between the DL signal and the UL signal for each of the one or more pairs of Tx/Rx beams to a threshold value, and identifying pairs of Tx/Rx beams in the one or more pairs of Tx/Rx beams for which the respective reception timing difference between the DL signal and the UL signal is below the threshold value. In some examples, the UE may be configured to set the threshold value to a cyclic prefix duration.

In some aspects, the UE determines the respective reception timing difference for each of the one or more pairs of Tx/Rx beams by determining a first reception time of a downlink transmission at a receive (Rx) beam of a pair of Tx/Rx beams in the one or more pairs of Tx/Rx beams, transmitting an uplink transmission from a transmit (Tx) beam of the pair of Tx/Rx beams in the one or more pairs of Tx/Rx beams, determining a second reception time of the uplink transmission at the receive (Rx) beam of the pair of Tx/Rx beams in the one or more pairs of Tx/Rx beams, and determining a duration between the first reception time and the second reception time. In some examples, the uplink transmission includes a sounding reference signal (SRS). For example, the uplink transmission may be transmitted based on a timing advance received from the base station. In some aspects, the second reception time of the uplink transmission is determined during one of the measurement gaps. In some aspects, the second reception time of the uplink transmission is determined during one of the measurement gaps.

In some aspects of the disclosure, the UE selects the at least one pair of Tx/Rx beams by identifying a pair of Tx/Rx beams in the one or more pairs of Tx/Rx beams based on at least one constraint applied to the respective reception timing difference between the DL signal and the UL signal. For example, the beam pair selection circuitry <NUM> shown and described above in connection with <FIG> may select at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements.

In some aspects of the disclosure, the configuration information further indicates a duration for one or more of the measurement gaps, where each of the self-interference measurements are performed via a sounding reference signal (SRS) transmission. In some examples, the duration may be indicated as one or more orthogonal frequency-division multiplexing (OFDM) symbols. In some aspects, the duration is indicated to the UE in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or in downlink control information (DCI). In some aspects, the configuration information further indicates an initial measurement gap between a channel measurement and one of the self-interference measurements.

At block <NUM>, the UE transmits a report including the selected at least one pair of Tx/Rx beams to the base station. For example, the report transmission circuitry <NUM>, together with the transceiver <NUM>, shown and described above in connection with <FIG> may transmit a report including the selected at least one pair of Tx/Rx beams to the base station.

<FIG> is a flow chart <NUM> of a method for wireless communication at a base station in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all aspects. In some examples, the process <NUM> may be carried out by the TRP-<NUM><NUM>, the TRP-<NUM><NUM>, or the base station <NUM> as illustrated in <FIG>. In some examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, the BS transmits, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements. For example, the configuration information transmission circuitry <NUM>, together with the transceiver <NUM>, shown and described above in connection with <FIG> may transmit, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE.

In some aspects, each of the measurement gaps enables the UE to determine a respective reception timing difference between a downlink (DL) signal and an uplink (UL) signal for each of one or more pairs of Tx/Rx beams from the subset of candidate beams. The BS refrains from scheduling downlink transmissions for the UE during the measurement gaps. In some aspects, at least one of the measurement gaps enables the UE to perform a beam switching operation. In some aspects, the configuration information further indicates a duration for one or more of the measurement gaps. In some examples, the duration is indicated as one or more orthogonal frequency-division multiplexing (OFDM) symbols. In some aspects, the BS indicates the duration to the UE in a radio resource control (RRC) message, a medium access control (MAC) control element (MAC-CE), or in downlink control information (DCI).

At block <NUM>, the BS receives, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements. For example, the report reception circuitry <NUM>, together with the transceiver <NUM>, shown and described above in connection with <FIG> may BS receive, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements.

In one configuration, the apparatus <NUM> for wireless communication includes means for receiving, from a base station, configuration information for performing beam pair selection measurements with respect to a subset of candidate beams at the apparatus, the beam pair selection measurements including at least self-interference measurements at the apparatus between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams, wherein the configuration information indicates measurement gaps between the self-interference measurements. The apparatus <NUM> further includes means for performing the beam pair selection measurements based on the configuration information, means for selecting at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements, and means for transmitting a report including the selected at least one pair of Tx/Rx beams to the base station.

In one aspect, the aforementioned means may be the processor <NUM> shown in <FIG> configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in the processor <NUM> is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium <NUM>, or any other suitable apparatus or means described in any one of the <FIG>, and utilizing, for example, the processes and/or algorithms described herein in relation to <FIG>.

In one configuration, the apparatus <NUM> for wireless communication includes means for transmitting, to a user equipment (UE), configuration information for beam pair selection measurements at the UE with respect to a subset of candidate beams at the UE. The beam pair selection measurements may include at least self-interference measurements at the UE between one or more transmit (Tx) beams and one or more receive (Rx) beams in the subset of candidate beams. The configuration information indicates measurement gaps between the self-interference measurements. The apparatus <NUM> further includes means for receiving, from the UE, a report including at least one pair of Tx/Rx beams selected by the UE based on the beam pair selection measurements.

As used herein, the term "obtaining" may include one or more actions including, but not limited to, receiving, generating, determining, or any combination thereof.

Claim 1:
A method of wireless communication for a user equipment, UE, (<NUM>; <NUM>; <NUM>; <NUM>), comprising:
receiving (<NUM>), from a scheduling entity (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), configuration information for performing beam pair selection measurements with respect to a subset of candidate beams at the UE (<NUM>; <NUM>; <NUM>; <NUM>), the beam pair selection measurements including at least self-interference measurements at the UE (<NUM>; <NUM>; <NUM>; <NUM>) between one or more transmit, Tx, beams and one or more receive, Rx, beams in the subset of candidate beams;
performing (<NUM>) the beam pair selection measurements based on the configuration information;
selecting (<NUM>) at least one pair of Tx/Rx beams from the subset of candidate beams based on the performed beam pair selection measurements; and
transmitting (<NUM>) a report including the selected at least one pair of Tx/Rx beams to the scheduling entity (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>), the method characterized in that the performing the beam pair selection measurements comprises determining a respective reception timing difference between a downlink, DL, signal and an uplink, UL, signal for each of one or more pairs of Tx/Rx beams from the subset of candidate beams and the configuration information indicates measurement gaps between transmissions for the self-interference measurements for enabling the timing difference determination.