Autonomous fallback for full-duplex beam pairs

Abstract

The present disclosure provides systems, devices, apparatuses, and methods for autonomous fallback for full-duplex beam pairs, including computer programs encoded on storage media. In a first aspect, a first wireless device may determine an occurrence of a performance trigger for a current beam pair used for full-duplex communication at the first wireless device, and use a fallback full-duplex beam pair in response to determining the occurrence of the performance trigger. In a second aspect, the first wireless communication device may receive an indication of an occurrence of a performance trigger for a current beam pair used for full-duplex communication from a second wireless device, and in response to receiving the indication, use the fallback full-duplex beam pair to communicate with the second wireless device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 035,421, filed on June 5, 2020, and entitled “AUTONOMOUS FALLBACK FOR FULL-DUPLEX BEAM PAIR,” and U.S. Patent Application No. 17 / 322,328, filed on May 17, 2021, and entitled “AUTONOMOUS FALLBACK FOR FULL-DUPLEX BEAM PAIR,” the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to wireless communications, and more particularly to autonomous backoff for backup full-duplex (FD) beam pairs. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution released by the Third Generation Partnership Project (3GPP) to meet new requirements and other requirements associated with latency, reliability, security, scalability (e.g., in the case of the Internet of Things (IoT)). 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There is a need for further improvement of 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an exhaustive review of all contemplated aspects, and is neither intended to identify key or important elements of all aspects, nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be presented later.

[0007] In FD operation, a downlink (DL) / uplink (UL) beam pair (e.g., a current FD beam pair) used for communication between a first wireless device and a second wireless device may become degraded or reach a point of failure based on self-interference or other interference within the environment of the wireless devices. When the current FD beam pair degrades below a predetermined quality threshold, one or more of the wireless devices may require a meaningful amount of time to perform self-interference measurements and / or calibrations on other beam pairs to determine a new FD beam pair with a threshold quality level that can replace the current FD beam pair. During the measurement and calibration period, at least some FD operations may need to be suspended, which may thereby cause increased latency, overhead, and disruption to the current communication link between the first wireless device and the second wireless device.

[0008] Thus, the wireless device may predetermine a fallback FD beam pair as a backup for maintaining FD operation at least during a measurement and calibration period for a new FD beam pair. The fallback FD beam pair may be determined based on explicit signaling (e.g., using a beam identifier (ID) or code point), or based on implicit rules, such as rules for mapping a current beam ID to a fallback beam ID. The switch to the fallback FD beam pair may be triggered proactively or reactively. For proactive triggering, a first wireless device may indicate a beam ID corresponding to a downgraded beam to a second wireless device, such that both wireless devices may replace the current FD beam with a fallback FD beam pair based on the fallback beam ID. For reactive triggering, the wireless device may utilize the fallback FD beam pair after an error has occurred (e.g., when no acknowledgment (ACK) is received in response to a transmission or when a negative acknowledgment (NACK) is received). After switching to the fallback FD beam pair, the wireless device can utilize the fallback FD beam pair alone (e.g., when the fallback FD beam pair is able to maintain a threshold quality level) or in combination with the degraded / current FD beam pair (e.g., if the fallback FD beam pair degrades below a threshold quality level, it can be used based on a multiplexing technique that can replicate transmissions on the fallback FD beam pair and the current FD beam pair).

[0009] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a wireless device at a UE, comprising a memory and at least one processor coupled to the memory. The memory may include instructions that, when executed by the at least one processor, cause the at least one processor to perform the following operations: determining an occurrence of a performance trigger for a current beam pair used for FD communication at the first wireless device; and using a fallback FD beam pair in response to determining the occurrence of the performance trigger.

[0010] In another aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a wireless device at a UE, comprising a memory and at least one processor coupled to the memory. The memory may include instructions that, when executed by the at least one processor, cause the at least one processor to perform the following operations: receiving an indication of an occurrence of a performance trigger for a current beam pair for FD communication from a second wireless device; and in response to receiving the indication, communicating with the second wireless device using a fallback FD beam pair.

[0011] To accomplish the foregoing and related ends, one or more aspects include features hereinafter fully described and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram illustrating an example of a wireless communication system and an access network.

[0013] Figure 2A , 2B , 2C and 2D are schematic diagrams showing examples of a first 5G / NR frame, a DL channel within a 5G / NR subframe, a second 5G / NR frame, and a UL channel within a 5G / NR subframe, respectively.

[0014] Figure 3 is a schematic diagram showing an example of a base station and a user equipment (UE) in an access network.

[0015] Figure 4 is a schematic diagram of an example integrated access and backhaul (IAB) network.

[0016] Figure 5 is a schematic diagram illustrating an example IAB network and its components.

[0017] Figures 6A-6C is a schematic diagram showing an example of FD communication.

[0018] Figure 7 is a call flow diagram illustrating communications between a first wireless device and a second wireless device in accordance with certain aspects of the present disclosure.

[0019] Figure 8 is a flow chart of a method for determining wireless communications of a wireless device for triggering occurrence of using a fallback FD beam pair.

[0020] Fig. 9 is a flow chart of a method of wireless communication for a wireless device receiving an indication of a trigger for using a fallback FD beam pair.

[0021] Fig.10 is a schematic diagram illustrating an example of a hardware implementation for an example apparatus.

[0022] Fig.11 is a schematic diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0023] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be implemented. In order to provide a thorough understanding of each concept, the detailed description includes specific details. However, it will be apparent to those skilled in the art that these concepts may be implemented without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid blurring such concepts.

[0024] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0025] For example, an element, or any part of an element, or any combination of elements can be implemented as a "processing system", which includes one or more processors. Examples of processors include: microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set operations (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform various functions described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language or other names, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, processes, functions, etc.

[0026] Accordingly, in one or more example embodiments, the described functions can be implemented with hardware, software or any combination thereof. If implemented with software, the functions can be stored on a computer-readable medium or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of computer-readable media of the above types, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0027] Figure 1 1 is a schematic diagram showing an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0028] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can also perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and transmission of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via a third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0029] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 can include an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input multiple output (MIMO) antenna technology, which includes spatial multiplexing, beamforming and / or transmit diversity. The communication link can be through one or more carriers. The base station 102 / UE 104 may use spectrum with a bandwidth of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0030] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0031] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) before communicating to determine whether the channel is available.

[0032] The small cell 102' may operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed spectrum used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may improve coverage and / or increase capacity of the access network.

[0033] The base station 102 (whether a small cell 102' or a large cell (e.g., a macro base station)) may include and / or be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) may operate in the traditional sub-6 GHz spectrum, in millimeter wave (mmW) frequencies, and / or near mmW frequencies to communicate with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is a portion of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and has a wavelength between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near mmW may extend down to frequencies of 3 GHz with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. The frequency range bands include frequency range 1 (FR1), which includes frequency bands below 7.225 GHz, and frequency range 2 (FR2), which includes frequency bands above 24.250 GHz. Communications using mmW / near mmW radio frequency (RF) bands (e.g., 3 GHz–300 GHz) have extremely high path loss and short range. The base station / UE may operate within one or more frequency range bands. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. The base station 180 and the UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming.

[0034] Base station 180 may transmit beamformed signals in one or more transmit directions 182' to UE 104. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182". UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of base station 180 / UE 104. The transmit direction and receive direction for base station 180 may be the same or may be different. The transmit direction and receive direction for UE 104 may be the same or may be different.

[0035] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area that broadcasts a specific service, and may be responsible for session management (start / stop) and collecting eMBMS-related billing information.

[0036] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a packet switching (PS) stream (PSS) service, and / or other IP services.

[0037] A base station may also include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver, a radio base station, a radio transceiver, a transceiver functional unit, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other appropriate term. The base station 102 provides an access point to the EPC 160 or the core network 190 for the UE 104. Examples of UE 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio unit, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some of the UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, an oven, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0038] Reference again Figure 1 In some aspects, UE 104 may be configured to: determine an occurrence of a performance trigger for a current beam pair used for FD communication at a first wireless device; and use a fallback FD beam pair in response to determining the occurrence of the performance trigger (198). Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0039] Figure 2A 200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B is a diagram 230 showing an example of DL channels within a 5G / NR subframe. Figure 2C 250 is a diagram illustrating an example of a second subframe within a 5G / NR frame structure. Figure 2D 280 is a diagram showing an example of an UL channel within a 5G / NR subframe. The 5G / NR frame structure can be frequency division duplex (FDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), subframes within the subcarrier set are dedicated to either DL or UL), or can be time division duplex (TDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), subframes within the subcarrier set are dedicated to both DL and UL). Figure 2A , 2C In the example provided, the 5G / NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 34 (most of which are UL). Although subframes 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured to have a slot format (dynamically configured by DL control information (DCI) or semi-statically / statically configured by radio resource control (RRC) signaling) through a received slot format indicator (SFI). It should be noted that the following description also applies to the 5G / NR frame structure as TDD.

[0040] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes (1ms) of equal size. Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single stream transmission). The number of time slots in a subframe may be based on the time slot configuration and numerology. For slot configuration 0, different digital schemes μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and digital scheme μ, there are 14 symbols / slot and 2 μ time slots / subframe. The subcarrier spacing and symbol length / duration are functions of the digital scheme. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is digital scheme 0 to 4. Therefore, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2D An example is provided for a slot configuration 0 with 14 symbols per slot and a digital scheme μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency division multiplexed (see Figure 2B ). Each BWP can have a specific numbering scheme.

[0041] The resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)), which extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0042] like Figure 2AAs shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as R for a specific configuration). x , where 100x is the port number, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0043] Figure 2B Examples of various DL channels within a subframe of a frame are shown. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), and each REG includes four consecutive REs in one OFDM symbol. The PDCCH within a BWP may be referred to as a control resource set (CORESET). Additional BWPs may be located at higher and / or lower frequencies across the channel bandwidth. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identification group number and radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the position of the above-mentioned DM-RS. The physical broadcast channel (PBCH), which carries the master information block (MIB), can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not sent through the PBCH (e.g., system information block (SIB)), and paging messages.

[0044] like Figure 2CAs shown in , some of the REs carry DM-RS for channel estimation at the base station (indicated as R for a specific configuration, but other DM-RS configurations are possible). The UE can send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first one or two symbols of the PUSCH. In different configurations, the PUCCH DM-RS can be sent depending on whether a short PUCCH or a long PUCCH is sent and according to the specific PUCCH format used. The UE can send a sounding reference signal (SRS). The SRS can be sent in the last symbol of the subframe. The SRS can have a comb structure, and the UE can send the SRS on one of the combs. The SRS can be used by the base station for channel quality estimation to achieve frequency-dependent scheduling on the UL.

[0045] Figure 2D Examples of various UL channels within a subframe of a frame are shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) / negative acknowledgement (NACK) feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0046] Figure 33 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with: broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with: header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and switching support functions; RLC layer functions associated with: transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0047] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation diagram based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived based on reference signals and / or channel condition feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0048] At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the UE 350. If multiple spatial streams are destined for the UE 350, the RX processor 356 can merge them into a single OFDM symbol stream. The RX processor 356 then transforms the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functions.

[0049] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0050] Similar to the functions described for DL ​​transmission performed in conjunction with the base station 310, the controller / processor 359 provides: RRC layer functions associated with: system information (e.g., MIB, SIB) capture, RRC connection, and measurement reporting; PDCP layer functions associated with: header compression / decompression, and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with: transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0051] The TX processor 368 may select an appropriate coding and modulation scheme and facilitate spatial processing using channel estimates derived by the channel estimator 358 based on a reference signal or feedback sent by the base station 310. The spatial streams generated by the TX processor 368 may be provided via separate transmitters 354TX to different antennas 352. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0052] At the base station 310, the UL transmission is processed in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0053] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0054] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform a combined Figure 1 All aspects of 198.

[0055] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform a combined Figure 1 All aspects of 198.

[0056] Figure 4 is a schematic diagram illustrating an integrated access and backhaul (IAB) network 400. The IAB network 400 may include an anchor node (which may be referred to herein as an "IAB donor") 410 and an access node (which may be referred to herein as an "IAB node") 420. The IAB donor 410 may be a base station (such as a gNB or an eNB), and may perform a function for controlling the IAB network 400. The IAB node 420 may include an L2 relay node, etc. The IAB donor 410 and the IAB node 420 share resources together to provide an access network and a backhaul network to a core network 490. For example, resources may be shared between an access link and a backhaul link in the IAB network.

[0057] UE 430 interfaces with IAB node 420 or IAB donor 410 through access link 470. IAB node 420 communicates with each other and with IAB donor 410 through backhaul link 460. IAB donor 410 is connected to core network 490 via wired backhaul link 450. UE 430 communicates with the core network by relaying messages to IAB network 400 through their respective access link 470, which then relays the messages to IAB donor 410 through backhaul link 460 to communicate with the core network through wired backhaul link 450. Similarly, the core network can communicate with UE 430 by sending messages to IAB donor 410 through wired backhaul link 450. The IAB donor 410 transmits a message to the IAB node 420 connected to the UE 430 via the backhaul link 460 through the IAB network 400 , and the IAB node 420 transmits a message to the UE 430 via the access link 470 .

[0058] Each IAB node (e.g., including the IAB donor 410 and each IAB node 420) can use a PCI value. The PCI value can serve as an identifier for the IAB donor 410 or the IAB node 420. The PCI value can be used to determine the scrambling sequence applied to the physical signal and / or channel sent by a specific IAB node. For example, a scrambling sequence based on the PCI used by the corresponding IAB node can be used to scramble the PSS and / or SSS sent by the corresponding IAB donor 410 or the IAB node 420. The network may have a limited number of available PCI values. For example, a 5G NR system may support 1008 PCI values. Therefore, a given PCI value may be reused in the same network.

[0059] Figure 5 5 is a schematic diagram showing an IAB network 500 and its components. The IAB network 500 includes an IAB donor 510 and an IAB node 520. The IAB node and the IAB donor can provide a wireless access link to a UE 530, respectively.

[0060] The IAB donor 510 can be considered as the root node of the tree structure of the IAB network 500. The IAB donor node 510 can be connected to the core network 590 via a wired connection 591. The wired connection can include, for example, a wired optical fiber. The IAB donor node 510 can provide a connection to one or more IAB nodes 520a. The IAB nodes 520a can each be referred to as a child node of the IAB donor node 510. The IAB donor node 510 can also provide a connection to one or more UEs 530a, and the UE 530a can be referred to as a child UE of the IAB donor 510. The IAB donor 510 can be connected to its child IAB node 520a via a backhaul link 560, and can be connected to the child UE 530a via an access link 570. The IAB node 520a as a child node of the IAB node 510 can also have an IAB node 520b and / or a UE 530b as a child node. For example, the IAB node 520b can also be connected to a child node and / or a child UE. Figure 5 The IAB nodes 520b are shown providing access links to the UEs 530c respectively.

[0061] The IAB donor 510 may include a central unit (CU) and a distributed unit (DU). The central unit CU may provide control for the IAB nodes 520a, 520b in the IAB network 500. For example, the CU may be responsible for the configuration of the IAB network 500. The CU may perform RRC / PDCP layer functions. The DU may perform scheduling. For example, the DU may schedule resources for communication performed by the child IAB node 520a and / or the UE 530a of the IAB donor 510.

[0062] The IAB nodes 520a, 520b may include a mobile terminal (MT) and a DU. The MT of the IAB node 520a may operate as a scheduled node, similar to the scheduling of the UE 530a by the DU of the parent node (e.g., the IAB donor 510). The MT of the IAB node 520b may operate as a scheduled node of the parent node 520a. The DU may schedule the child IAB node 520b and the UE 530b of the IAB node 520a. Because the IAB node may provide a connection to an IAB node, the IAB node in turn provides a connection for another IAB node. The pattern of the parent IAB node including the DU scheduling the child IAB node / child UE may continue until Figure 5 More connections shown in .

[0063] A wireless device can send and receive communications in full-duplex (FD) mode, in which the device uses overlapping resources to send and receive communications. For example, FD operation may involve simultaneous UL and DL transmissions. Flexible time division duplex (TDD) operation can support FD communications. In a wireless communication system that supports FD communications, wireless devices may experience self-interference that degrades communications. If the transmitted signal leaks to the receiving port of the transmitting device, self-interference may occur. In addition, the transmitted signal may be reflected back to the receiving port by an object, which may be referred to as a clutter echo. Reducing self-interference (especially clutter echoes) via spatial isolation by appropriately selecting transmit and receive beams or more advanced transmit / receive beamforming can help support FD communications.

[0064] Flexible TDD capabilities (including FD capabilities) may be capabilities of a UE, base station, IAB node, parent node, and / or child node. For example, a UE may be able to send UL transmissions from one antenna panel while performing DL reception using another antenna panel. In some aspects, the capabilities may depend on beam separation, use of different panels, etc.

[0065] Flexible TDD functionality and FD mode can reduce latency for communications by sending and receiving simultaneously. For example, receiving DL signals in UL time slots can enable UEs to receive DL communications from base stations faster and reduce latency for such communications. Spectral efficiency can be improved, including improvements per cell and / or per UE. FD mode can provide more efficient resource utilization.

[0066] Self-interference measurement (SIM) may be performed to determine whether FD capability may be supported or whether FD capability may be enabled / enhanced at the wireless device. To perform self-interference measurement, the wireless device may transmit signals from a first set of antennas in one or more transmit beam directions and may measure signals (e.g., reflected or leaked transmission signals) received on a second set of antennas in one or more receive beam directions.

[0067] In some cases, the wireless device may receive a configuration for performing self-interference measurements from a network entity. The network entity may provide a configuration / resource for the wireless device to perform self-interference measurements. The network entity may configure the wireless device to provide a report of the self-interference measurements. The network entity may determine the FD capabilities, conditions, and / or performance of the wireless device based on the received report of the self-interference. However, the network entity may not consider clutter echoes when configuring the wireless device to perform self-interference measurements.

[0068] In some cases, the wireless device may be configured to perform self-interference measurements without specific instructions from a network entity. For example, a network entity (e.g., a distributed unit (DU)) may send a DL signal (e.g., SSB / CSI-RS). The wireless device may measure which level of DL signal is received in terms of reference signal received power (RSRP) on its receive port / antenna. In another example, if a UE or mobile terminal (MT) is scheduled to send an UL signal (e.g., SRS), the UE or MT may perform self-interference measurements on its receive port / antenna. In some cases, the wireless device may not provide any report on the self-interference measurement to another entity (e.g., the network). The wireless device may use self-interference measurements to determine whether it supports FD or for beam tuning. However, the wireless device may not take clutter echoes into account when performing self-interference measurements.

[0069] Figures 6A-6C 600 , 610 , 620 are schematic diagrams of examples of FD communication. Fig. 6A The example 600 includes UE1 602 and two base stations (eg, TRPs) 604-1, 604-2, wherein UE1 602 is sending UL transmissions to base station 604-1 and is receiving DL transmissions from base station 604-2, for example, in a simultaneous manner that overlaps in time. Fig. 6A In example 600 , FD is enabled for UE1 602 , but FD is not enabled for base stations 604 - 1 , 604 - 2 . Figure 6B Example 610 includes two UEs (UE1 602-1 and UE2 602-2) and a base station 604, wherein UE1 602-1 is receiving a DL transmission from the base station 604 and UE2 602-2 is sending an UL transmission to the base station 604, e.g., in a simultaneous manner that overlaps in time. Figure 6B In example 610, FD is enabled for base station 604, but FD is not enabled for UEs (UE1 602-1 and UE2 602-2). Figure 6C Example 620 includes UE1 602 and base station 604, where UE1 602 is receiving a DL transmission from base station 604 and UE1 602 is sending an UL transmission to the same base station 604, e.g., in a simultaneous manner that overlaps in time. Figure 6C In example 620 , FD is enabled for both UE1 602 and base station 604 .

[0070] The present disclosure relates to improving the manner in which self-interference measurements can be configured. The self-interference measurement configuration can be adjusted in response to a detected clutter echo. For example, a wireless device can be configured to detect a clutter echo, and such a result can be reported to a network entity so that the network entity can adjust the self-interference configuration. In another example, the wireless device can be configured to detect a clutter echo, and a self-interference measurement configuration can be requested in view of the detected clutter echo. Configuring the self-interference measurement to take into account the detected clutter echo can help perform the self-interference measurement. Therefore, it is desirable to improve the manner in which the self-interference measurement is configured to allow for the detection of clutter echoes.

[0071] Beam separation of the transmit and receive beams helps limit or reduce self-interference that may occur during FD communications. It is desirable to consider clutter echoes when configuring self-interference measurements to minimize self-interference. Determining whether clutter echoes are present may allow for adjustment of the self-interference measurement configuration, which may provide reliable FD communications by selecting beam pairs that minimize or reduce self-interference.

[0072] Figure 7 700 is a call flow diagram illustrating communications between a first wireless device 702 and a second wireless device 704. In some aspects, the first wireless device 702 may be a UE and the second wireless device 704 may be a base station, wherein the base station provides a cell serving the UE. In other examples, the first wireless device 702 may be a UE and the second wireless device 704 may be an IAB node. In other examples, the first wireless device may be an IAB node (e.g., a child node) and the second wireless device may be a parent IAB node, a donor node, or a base station. For example, in Figure 1 In the context of , the second wireless device 704 can correspond to a base station 102 / 180 or an IAB node, and thus, a cell can include a geographic coverage area 110 and / or a small cell 102' having a coverage area 110' in which communication coverage is provided. In addition, the first wireless device 702 can correspond to a UE 104 or an IAB node. In another example, in Figure 3 In the context of , the second wireless device 704 may correspond to the device 310 and the first wireless device 702 may correspond to the device 350 .

[0073] At 706, the first wireless device 702 may receive an indication of a fallback FD beam pair from the second wireless device 704. The indication may include a beam identifier (ID) of the fallback FD beam pair (e.g., a UL beam ID, a DL beam ID, or a beam pair ID). Additionally or alternatively, the indication may include a transmission configuration indicator (TCI) code point mapped to a TCI state. At 708, the first wireless device 702 may determine that a trigger for the fallback FD beam pair has occurred. The trigger may include a beam failure, a beam quality / performance that falls below a threshold level, a self-interference measurement that is above a threshold amount, and the like. Such a threshold may be configured by the second wireless device 704 (e.g., a network) via an indication sent to the first wireless device 702 at 706.

[0074] At 710, the first wireless device 702 may provide an indication of the occurrence of the trigger to the second wireless device 704. At 712, in response to the indication of the trigger, the second wireless device 704 may indicate to the first wireless device 702 to use a fallback FD beam pair (e.g., the fallback FD beam pair previously indicated to the first wireless device 702 at 706). At 714a-b, the first wireless device 702 and the second wireless device 704 may each use the fallback FD beam pair to maintain FD communication.

[0075] At 716a-b, the first wireless device 702 and the second wireless device 704 may each perform self-interference measurements to determine a new beam pair for FD communication, which may replace the beam pair that provided the trigger. At 718, the first wireless device 702 may provide an indication of the self-interference measurement to the second wireless device 704. At 720a-b, based on the self-interference measurement, the first wireless device 702 and the second wireless device 704 may switch from the fallback FD beam pair to the new beam pair determined based on the self-interference measurement to maintain FD communication between the first wireless device 702 and the second wireless device 704.

[0076] In FD operation, a DL / UL beam pair initially identified by the first wireless device 702 for communicating with the second wireless device 704 may become degraded or reach a point of failure based on self-interference caused by leakage from the transmitter of the first wireless device 702 to the receiver of the first wireless device 702. Therefore, a second DL / UL beam pair (e.g., a fallback FD beam pair) may be predetermined by the wireless devices 702-704 as a backup for maintaining FD operation when the initial DL / UL-beam pair (e.g., the current FD beam pair) degrades below a predetermined threshold. In certain aspects, movement / rotation of the first wireless device 702 or moving objects / reflectors in the environment of the first wireless device 702 may cause the quality of the current FD beam pair to degrade below a predetermined threshold. Prior to a change in conditions of the first wireless device 702 or a change in conditions in the associated environment, the current FD beam pair used to provide an FD link between the wireless devices 702-704 may be assumed to have a threshold quality level unless / until at least one of the wireless devices 702-704 detects a degraded condition.

[0077] If the current FD beam pair is degraded to below the threshold quality level, the first wireless device 702 may need to rely on the fallback FD beam pair to maintain the threshold quality level. In the case of a degraded FD beam pair, the first wireless device 702 may need a meaningful amount of time to perform self-interference measurements and calibrations on other beam pairs to determine a replacement / new FD beam pair with a threshold quality level to replace the current FD beam pair. During the measurement and calibration period, at least some FD operations may need to be suspended, which may thereby cause increased overhead and interruption to the existing communication link between the first wireless device 702 and the second wireless device 704. The initial process for determining the beam pair may be based on self-interference measurements, which indicate the beam that causes the minimum amount of self-interference. The first wireless device 702 and the second wireless device 704 (e.g., FD nodes) can measure the self-interference level of the transmission on the other beam in the beam pair using RSs sent in two directions. Then, the first wireless device 702 can generate a confirmation indicating, for example, the first N beams (e.g., 3 beams) that can be used to perform FD communication.

[0078] Having a predetermined fallback FD beam pair for the first wireless device 702 can reduce the time period required to switch from the current FD beam pair to a different FD beam pair after degradation. The first wireless device 702 can utilize the fallback FD beam pair at least during the measurement and calibration period while determining a replacement beam pair for the current FD beam pair. In some examples, the fallback FD beam pair can be a replacement beam pair for the current FD beam pair. The fallback FD beam pair can be explicitly signaled or determined based on implicit rules. Switching to the fallback FD beam pair can be triggered actively or reactively based on the degradation of the current FD beam pair, and after the switch occurs, the fallback FD beam pair can be used alone or in combination with the current FD beam pair that has been degraded. The fallback FD beam pair can be configured so that both the first wireless device 702 and the second wireless device 704 can switch to the fallback FD beam pair if the quality of the current FD beam pair is degraded below a threshold quality level. In each example, the threshold quality level can be configurable.

[0079] In some configurations, explicit signaling from the second wireless device 704 may be used to indicate the fallback FD beam pair. The first wireless device 702 may be configured to send a report indicating a candidate beam pair for the fallback FD beam pair to the second wireless device 704, and based on the candidate beam pair, the second wireless device 704 may signal one or more IDs for the fallback FD beam pair to the first wireless device 702 via DCI, MAC control element (MAC-CE), RRC signaling, etc. Each beam in the fallback FD beam pair may be identified by the first wireless device 702 based on the ID. For example, the beam ID may indicate the UL and DL TCI states to be used for the fallback FD beam pair. The first type of beam ID may indicate a separate UL / DL TCI state. The second type of beam ID may indicate a single TCI beam pair, such as a code point mapped to both UL and DL TCI states.

[0080] In other configurations, an implicit rule may be used to determine the fallback FD beam pair. For example, both the first wireless device 702 and the second wireless device 704 may utilize past beam pair measurements performed by the first wireless device 702 to determine the fallback FD beam pair to be used in the event that the current FD beam pair is degraded. The fallback FD beam pair may be selected from a subset of past beam pair measurements. In one example, the first wireless device 702 may determine the top N FD beam pairs with the best quality and report them to the second wireless device 704. The determination may be based on a layer 1 (L1) RSRP or L1 signal to interference plus noise ratio (SINR) for each DL and UL beam for each beam pair.

[0081] Based on the subset of reported FD beam pairs, an implicit rule for determining the fallback FD beam pair may be indicated or defined. For example, the implicit rule may be that the beams in the fallback FD beam pair correspond to beam X and beam X+1 in the total number of beam pairs included in the subset of reported FD beam pairs. The value of X may point to the fallback FD beam pair, may be determined based on a fixed rule, or the value of X may be dynamically signaled by the second wireless device 704. Such a technique may be different from sending a beam ID, because beams X and X+1 corresponding to the fallback FD beam pair may be determined based on direct measurements of the beams from a previous reporting instance of the first wireless device 702.

[0082] The quality of the current FD beam pair may be monitored so that if the quality of the current FD beam pair is degraded below a predetermined threshold, the first wireless device 702 and / or the second wireless device 704 may be actively triggered to switch to the fallback FD beam pair. The quality of the UL and DL beams in the current FD beam pair may be determined / measured based on L1-RSRP / L1-SINR using the corresponding UL / DLRS, or estimated based on a block error rate (BLER). RS may include CSI-RS, SRS, positioning reference signal (PRS), SSB, etc. Some RS may be periodically sent and monitored in UL and DL (e.g., at opposite nodes). That is, UL and DL nodes may be expected to measure RS. In DL, RS may be CSI-RS or SSB. In UL, RS may be SRS. Based on the measurement of RS in terms of L1-RSRP / L1-SINR or the mapping to a higher rate being at the SINR threshold, the first wireless device 702 may determine that the current FD beam pair has failed or degraded below a predetermined threshold. The first wireless device 702 may then switch to the fallback FD beam pair.

[0083] The wireless devices 702-704 may be configured to switch to a fallback FD beam pair if the measured quality of the current FD beam pair degrades below a predetermined threshold. In various examples, multiple beam pair sets may be monitored simultaneously. In addition, subsets of multiple beam pair sets may have different quality thresholds. The first wireless device 702 and / or the second wireless device 704 may send a beam ID of the current FD beam pair so that the beam ID may be replaced with a beam ID of the fallback FD beam pair. In various examples, different beam IDs may be associated with different quality thresholds. If the first beam ID for the current FD beam pair becomes associated with a failure or threshold degradation level, the beam of the fallback FD beam pair may be determined based on a TCI state identifier, which may be explicitly signaled or may be determined based on an implicit rule. In the case of multiple beam IDs, the implicit rule for mapping the current beam ID to the fallback beam ID may be that the first current beam ID may be mapped to the first fallback beam ID, the second current beam ID may be mapped to the second fallback beam ID, and so on.

[0084] In another aspect, if it is determined that the current FD beam pair has degraded below a predetermined threshold, the fallback FD beam pair may be triggered reactively rather than actively monitoring the quality of the current FD beam pair. Although reactively triggering the fallback FD beam pair may provide a delay based on the need for communication on the FD link, the fallback FD beam pair only needs to be determined when an error / degradation occurs with respect to the FD link. For example, if the first wireless device 702 sends a communication to another node and receives a NACK in response to the communication, or does not receive anything in response to the communication (e.g., no ACK), the first wireless device 702 may determine that the current FD beam pair has degraded / failed. In such a case, both nodes may need to switch to the fallback FD beam pair for subsequent communications (e.g., via PDCCH, PDSCH, PUCCH, and / or PUSCH).

[0085] While reactive triggering can reduce overhead by eliminating the need to send RSs between nodes on a periodic basis, an actual failure may need to occur before a node can switch to a fallback FD beam pair. Once a particular communication has failed (e.g., based on a missing ACK from a receiving node), the two nodes may need to switch to a fallback FD beam pair for subsequent communications. If communications are currently being sent over a channel on one of the beams in the current FD beam pair, and no ACK is received for that channel, the sending node may switch to the fallback FD beam pair. Such an aspect may be contrasted with proactive triggering, in which a switch to a fallback FD beam pair may be performed before communications are sent.

[0086] The first wireless device 702 and the second wireless device 704 may communicate based on the fallback FD beam pair alone, or the first wireless device 70 and the second wireless device 704 may communicate based on the fallback FD beam pair together with the current FD beam pair that is determined to include degraded quality. In a first example, after switching to the fallback FD beam pair, if the fallback FD beam pair is able to maintain a threshold quality level, the first wireless device 702 and the second wireless device 704 may not attempt to reconnect on the FD link provided via the initial FD beam pair. Therefore, the initial FD beam pair may be replaced by the fallback FD beam pair (e.g., at least temporarily). In a second example, after the initial FD beam pair is degraded to below the threshold quality level, the fallback FD beam pair may be degraded to the threshold quality level. Therefore, multiplexing techniques such as time division multiplexing (TDM), frequency division multiplexing (FDM), or space division multiplexing (SDM) may be used to replicate transmissions on the initial FD beam pair and the fallback FD beam pair to improve reliability.

[0087] Figure 8 800 is a flow chart of a method of wireless communication of a wireless device (e.g., a first wireless device 702) that determines the occurrence of a trigger for using a fallback FD beam pair. The first wireless device 702 may be an IAB node (e.g., a subnode) or a UE, which may include a memory 360 and may be the entire UE or a component of the UE (such as a TX processor 368, an RX processor 356, and / or a controller / processor 359).

[0088] At 802, the wireless device may receive an indication from a second wireless device indicating a fallback FD beam pair (eg, before the wireless device determines an occurrence of a performance trigger). Figure 7 At 706, the first wireless device 702 may receive an indication of a fallback FD beam pair from the second wireless device 704. The fallback FD beam pair may be indicated (e.g., at 706) by one or more of: a UL beam ID for a UL beam in the fallback FD beam pair, a DL beam ID for a DL beam in the fallback FD beam pair, a beam pair ID for a fallback FD beam pair, or a TCI code point mapped to UL and DL TCI states for a fallback FD beam pair. In addition, the indication at 706 may be transmitted in one or more of DCI, MAC-CE, or RRC signaling.

[0089] At 804, the wireless device may determine the occurrence of a performance trigger for a current beam pair used for FD communication at the wireless device. Figure 7At 708, the first wireless device 702 may determine that a trigger for utilizing a fallback FD beam pair has occurred. The performance trigger (e.g., indicated to the second wireless device 704 at 710) may include one or more of: a beam failure for at least one beam in the current beam pair, a beam performance below a threshold performance level for the current beam pair, a beam quality measurement below a threshold quality level for at least one beam in the current beam pair, or a self-interference measurement above a threshold interference level for the current beam pair. The performance trigger (e.g., determined to occur at 708) may be based on a communication error that may have occurred, for example, based on the reception or transmission of a NACK. Additionally or alternatively, the performance trigger (e.g., determined to occur at 708) may be based on a beam quality measurement including at least one of the following: RSRP for a reference signal, SINR for a reference signal, or BLER for at least one beam in the current beam pair. The reference signal may include at least one of a CSI-RS, an SRS, a PRS, or an SSB.

[0090] At 806, the wireless device may determine a fallback FD beam pair based on a rule. Figure 7 , at 708, the first wireless device 702 can determine the occurrence of a trigger for a fallback FD beam pair based on a rule, such as an explicit rule (e.g., a rule that can be defined or received from the second wireless device 704) or an implicit rule (e.g., a rule that can be based on at least one of: a subset of FD beam pairs reported from the first wireless device 702, or a current beam pair used by the first wireless device 702 and the second wireless device 704).

[0091] At 808, the wireless device may signal to the second wireless device that the beam quality measurement is below a threshold quality level. Figure 7 At 710, the first wireless device 702 may signal the second wireless device 704 that the beam measurement and / or the self-interference measurement is below a threshold level. In one example, the first wireless device 702 may be a UE, and the second wireless device 704 may be a base station or an IAB node. In another example, the first wireless device 702 may be an IAB node (e.g., a child node), and the second wireless device 704 may be a parent IAB node.

[0092] At 810, the wireless device may receive an indication from a second wireless device to use a fallback FD beam pair, wherein the first wireless device uses the fallback FD beam pair based at least in part on the indication. Figure 7At 712, the first wireless device 702 may receive an indication to use a fallback FD beam pair from the second wireless device 704. The fallback FD beam pair may be explicitly indicated at 706, or the fallback FD beam pair may be implicitly indicated based on a rule. In various examples, the fallback FD beam pair may be determined based on the current beam pair.

[0093] At 812, the wireless device may use a fallback FD beam pair in response to determining that a performance trigger occurs. Figure 7 , after determining at 708 that a trigger for the fallback FD beam pair has occurred, the first wireless device 702 may use the fallback FD beam pair at 714a. The first wireless device 702 may use the fallback FD beam pair for one or more of the following: PDCCH, PDSCH, PUSCH, or PUCCH. In various aspects, at 714a, the first wireless device 702 may use the fallback FD beam pair without continuing to use the current beam pair. In other aspects, at 714a, the first wireless device 702 may continue to use the current beam pair and use the fallback FD beam pair. For example, at 714a, the first wireless device 702 may use the current beam pair and the fallback FD beam pair for duplicate communication. Additionally or alternatively, the first wireless device 702 may use a multiplexing scheme to communicate on the current beam pair and the fallback FD beam pair.

[0094] At 814, the wireless device may perform self-interference measurements in response to determining the occurrence of a performance trigger to determine a new beam pair for FD communication. Figure 7 , after determining at 708 that a trigger for utilizing the back-off FD beam pair has occurred, the first wireless device 702 may perform a self-interference measurement at 716a.

[0095] At 816, the wireless device may switch from the fallback FD beam pair to the new beam pair based on the self-interference measurement. Figure 7 At 720a, the first wireless device 702 may switch from the fallback FD beam pair to the new FD beam pair based on the self-interference measurement performed at 716a.

[0096] Fig. 9 Flowchart 900 of a method of wireless communication of a wireless device (e.g., a second wireless device 704) that receives an indication of a trigger for using a fallback FD beam pair. The wireless device 702 may be an IAB node (e.g., a parent node / donor node) or a base station, which may include a memory 376, and may be the entire base station or a component of a base station (such as a TX processor 316, an RX processor 370, and / or a controller / processor 375).

[0097] At 902, the wireless device may indicate a fallback FD beam pair to another wireless device (eg, before the wireless device receives an indication of an occurrence of a performance trigger). Figure 7 At 706, the wireless device 704 may indicate the fallback FD beam pair to the other wireless device 702. The fallback FD beam pair may be indicated (e.g., at 706) by one or more of: a UL beam ID for a UL beam in the fallback FD beam pair, a DL beam ID for a DL beam in the fallback FD beam pair, a beam pair ID for the fallback FD beam pair, or a TCI code point mapped to UL and DL TCI states for the fallback FD beam pair. In addition, the indication at 706 may be transmitted in one or more of DCI, MAC-CE, or RRC signaling.

[0098] At 904, the wireless device may receive an indication of an occurrence of a performance trigger for a current beam pair for FD communication from another wireless device. Figure 7 At 710, the wireless device 704 may receive an indication of a performance trigger from another wireless device 702 to use the fallback FD beam pair for FD communication. The performance trigger (e.g., indicated at 710) may include one or more of the following: beam failure for at least one beam in the current beam pair, beam performance below a threshold performance level for the current beam pair, beam quality measurement below a threshold quality level for at least one beam in the current beam pair, or self-interference measurement above a threshold interference level for the current beam pair. The performance trigger (e.g., indicated at 710) may be based on a beam quality measurement including at least one of the following: RSRP for a reference signal, SINR for a reference signal, or BLER for at least one beam in the current beam pair. The reference signal may include at least one of a CSI-RS, an SRS, a PRS, or an SSB.

[0099] At 906, the wireless device may determine a fallback FD beam pair based on a rule. Figure 7At 706, the wireless device 704 may provide an indication of a rule-based fallback FD beam pair to the other wireless device 702, such as an explicit rule (e.g., a rule that may be defined or sent to the other wireless device 702) or an implicit rule (e.g., a rule that may be based on at least one of the following: a subset of reported FD beam pairs received from the other wireless device 702, or a current beam pair used by the wireless device 704 and the other wireless device 702). In one example, the wireless device 704 may be a base station or an IAB node, and the other wireless device 702 may be a UE. In another example, the wireless device 704 may be a parent IAB node, and the other wireless device 702 may be a child IAB node.

[0100] At 908, the wireless device may indicate to another wireless device to use a fallback FD beam pair in response to receiving an indication of the occurrence of a performance trigger. Figure 7 At 712, the wireless device 704 may indicate the use of the fallback FD beam pair to the other wireless device 702. The fallback FD beam pair may be determined based on the current beam pair.

[0101] At 910, the wireless device may, in response to receiving the indication, communicate with another wireless device using the fallback FD beam pair. Figure 7 , after receiving an indication of the occurrence of the trigger at 708, the wireless device 704 may use the fallback FD beam pair at 714b. In various aspects, at 714b, the wireless device 704 may use the fallback FD beam pair without continuing to use the current beam pair. In other aspects, at 714b, the wireless device 704 may continue to use the current beam pair and use the fallback FD beam pair. For example, at 714b, the wireless device 704 may use the current beam pair and the fallback FD beam pair for duplicate communications. Additionally or alternatively, the wireless device 704 may use a multiplexing scheme to communicate on the current beam pair and the fallback FD beam pair.

[0102] At 912, the wireless device may receive a self-interference measurement from another wireless device or perform a self-interference measurement. Figure 7 , the wireless device 704 may receive a self-interference measurement from another wireless device 702 at 718 or perform a self-interference measurement at 716b.

[0103] At 914, the wireless device may switch from the fallback FD beam pair to the new beam pair based on the self-interference measurement. Figure 7 At 720b, the wireless device 704 may switch from the fallback FD beam pair to the new FD beam based on the self-interference measurement performed at 716b or the self-interference metric received from another wireless device 702 at 718.

[0104] Fig.10 1 is a schematic diagram 1000 showing an example of a hardware implementation for an apparatus 1002. The apparatus 1002 is a UE and includes a cellular baseband processor 1004 (also referred to as a modem) coupled to a cellular RF transceiver 1022 and one or more subscriber identity modules (SIM) cards 1020, an application processor 1006 coupled to a secure digital (SD) card 1008 and a screen 1010, a Bluetooth module 1012, a wireless local area network (WLAN) module 1014, a global positioning system (GPS) module 1016, and a power supply 1018. The cellular baseband processor 1004 communicates with the UE 104 and / or the BS 102 / 180 through the cellular RF transceiver 1022. The cellular baseband processor 1004 may include a computer-readable medium / memory. The cellular baseband processor 1004 is responsible for general processing, including executing software stored on the computer-readable medium / memory. When executed by the cellular baseband processor 1004, the software causes the cellular baseband processor 1004 to perform the various functions described above. The computer-readable medium / memory may also be used to store data that is manipulated by the cellular baseband processor 1004 when executing the software.

[0105] The cellular baseband processor 1004 also includes a receiving component 1030, a communication manager 1032, and a transmitting component 1034. The communication manager 1032 includes one or more of the components shown. The components within the communication manager 1032 may be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 1004. The cellular baseband processor 1004 may be a component of the UE 350 and may include at least one of the TX processor 368, the RX processor 356, and the controller / processor 359 and / or the memory 360. In one configuration, the device 1002 may be a modem chip and include only the baseband processor 1004, and in another configuration, the device 1002 may be the entire UE (e.g., see Figure 3 350) and includes the additional modules of device 1002 described above.

[0106] The communication manager 1032 includes a determining component 1040 configured to determine an occurrence of a performance trigger for a current beam pair for FD communication at a first wireless device, and determine a fallback FD beam pair based on a rule, e.g., as described in conjunction with 804-806. The communication manager 1032 also includes a signal notifier component 1042 configured to signal to a second wireless device that a beam quality measurement is below a threshold quality level, e.g., as described in conjunction with 808. The communication manager 1032 also includes a using component 1044 configured to use the fallback FD beam pair in response to determining an occurrence of the performance trigger, e.g., as described in conjunction with 812. The communication manager 1032 also includes an executor component 1046 configured to perform a self-interference measurement in response to determining an occurrence of the performance trigger to determine a new beam pair for FD communication, e.g., as described in conjunction with 814. The communication manager 1032 also includes a switch component 1048 configured to switch from the fallback FD beam pair to the new beam pair based on the self-interference measurement, for example, as described in conjunction with 816. As described in conjunction with 802 and 810, the receiving component 1030 can be configured to receive an indication indicating the fallback FD beam pair from the second wireless device, and receive an indication to use the fallback FD beam pair from the second wireless device based at least in part on the indication.

[0107] The device may include performing the above Figure 8 Each box in the flowchart of the algorithm has an additional component. Therefore, the above Figure 8 Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of those components. The component can be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0108] In one configuration, the device 1002 (and specifically, the cellular baseband processor 1004) includes means for receiving, determining, signaling, using, executing, and switching. The aforementioned means may be one or more of the components of the device 1002 configured to perform the functions recited by the aforementioned means. As described above, the device 1002 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Therefore, in one configuration, the aforementioned means may be the TX processor 368, the RX processor 356, and the controller / processor 359, which are configured to perform the functions recited by the aforementioned means.

[0109] Fig.111 is a schematic diagram 1100 showing an example of a hardware implementation for an apparatus 1102. The apparatus 1102 is a BS and includes a baseband unit 1104. The baseband unit 1104 can communicate with the UE 104 via a cellular RF transceiver. The baseband unit 1104 may include a computer-readable medium / memory. The baseband unit 1104 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 1104, causes the baseband unit 1104 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the baseband unit 1104 when executing the software. The baseband unit 1104 also includes a receiving component 1130, a communication manager 1132, and a sending component 1134. The communication manager 1132 includes one or more of the components shown. The components within the communication manager 1132 may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 1104. The baseband unit 1104 may be a component of the BS 310 and may include at least one of the TX processor 316 , the RX processor 370 , and the controller / processor 375 , and / or the memory 376 .

[0110] The communication manager 1132 includes an indication component 1140 configured to indicate the fallback FD beam pair to the second wireless device, and in response to receiving an indication of the occurrence of a performance trigger, to indicate to the second wireless device to use the fallback FD beam pair, e.g., as described in conjunction with 902 and 908. The communication manager 1132 also includes a determination component 1142 configured to determine the fallback FD beam pair based on a rule, e.g., as described in conjunction with 906. The communication manager 1132 also includes a determination component 1142 configured to determine the fallback FD beam pair based on a rule, e.g., as described in conjunction with 906. The communication manager 1132 also includes a use component 1144 configured to communicate with the second wireless device using the fallback FD beam pair in response to receiving the indication, e.g., as described in conjunction with 910. The communication manager 1132 also includes a switch component 1146 configured to switch from the fallback FD beam pair to the new beam pair based on a self-interference measurement, e.g., as described in conjunction with 914. As described in conjunction with 904 and 912, receiving component 1130 may be configured to receive an indication of an occurrence of a performance trigger for a current beam pair for FD communication from a second wireless device and receive a self-interference measurement from the second wireless device.

[0111] The device may include performing the above Fig. 9 Each box in the flowchart of the algorithm has an additional component. Therefore, the above Fig. 9Each block in the flowchart of can be performed by a component, and the apparatus may include one or more of those components. The component can be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0112] In one configuration, the device 1102 (and specifically, the baseband unit 1104) includes units for indicating, receiving, determining, using, and switching. The aforementioned means may be one or more of the aforementioned components of the device 1102 configured to perform the functions recited by the aforementioned units. As described above, the device 1102 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Therefore, in one configuration, the aforementioned means may be a TX processor 316, an RX processor 370, and a controller / processor 375, which are configured to perform the functions recited by the aforementioned units.

[0113] Thus, the wireless device may predetermine a fallback FD beam pair as a backup for maintaining FD operation at least during a measurement and calibration period for the new FD beam pair. The fallback FD beam pair may be determined based on explicit signaling (e.g., using a beam ID or code point), or based on implicit rules, such as a rule for mapping a current beam ID to a fallback beam ID. The switch to the fallback FD beam pair may be triggered proactively or reactively. For proactive triggering, the first wireless device may indicate the beam ID corresponding to the downgraded beam to the second wireless device, so that both wireless devices may replace the current FD beam with a fallback FD beam pair based on the fallback beam ID. For reactive triggering, the wireless device may utilize the fallback FD beam pair after an error has occurred (e.g., when no ACK is received in response to a transmission or when a NACK is received). After switching to the fallback FD beam pair, the wireless device can utilize the fallback FD beam pair alone (e.g., when the fallback FD beam pair is able to maintain a threshold quality level) or in combination with the degraded / current FD beam pair (e.g., if the fallback FD beam pair degrades below a threshold quality level, it can be used based on a multiplexing technique that can replicate transmissions on the fallback FD beam pair and the current FD beam pair).

[0114] The following aspects are merely exemplary and may be combined with other embodiments or aspects of the teachings described herein without limitation.

[0115] Aspect 1 is a method of wireless communication at a first wireless device, comprising: determining an occurrence of a performance trigger for a current beam pair used for full-duplex communication at the first wireless device; and using a fallback full-duplex beam pair in response to determining the occurrence of the performance trigger.

[0116] In aspect 2, the method according to aspect 1 also includes: performing self-interference measurement to determine a new beam pair for full-duplex communication in response to determining the occurrence of the performance trigger; and switching from the fallback full-duplex beam pair to the new beam pair based on the self-interference measurement.

[0117] In aspect 3, the method according to aspect 1 or aspect 2 further comprises: before determining the occurrence of the performance trigger, receiving an indication indicating the fallback full-duplex beam pair from a second wireless device.

[0118] In aspect 4, the method according to aspect 3 also includes: the fallback full-duplex beam pair is indicated by one or more of the following: an uplink beam identifier (ID) for the uplink beam in the fallback full-duplex beam pair, a downlink beam ID for the downlink beam in the fallback full-duplex beam pair, a beam pair ID for the fallback full-duplex beam pair, or a TCI code point mapped to the uplink and downlink transmission configuration indicator (TCI) states for the fallback full-duplex beam pair.

[0119] In aspect 5, the method according to aspect 3 also includes: the indication is included in one or more of the following: downlink control information (DCI), medium access control-control element (MAC-CE), or radio resource control (RRC) signaling.

[0120] In aspect 6, the method according to any one of aspects 1-5 further includes: determining the fallback full-duplex beam pair based on a rule.

[0121] In aspect 7, the method according to aspect 6 further comprises: the rule is based on at least one of a subset of reported full-duplex beam pairs or the current beam pair.

[0122] In aspect 8, the method according to aspect 6 further comprises: the rule is defined or received from a second wireless device.

[0123] In aspect 9, the method according to any one of aspects 1-8 also includes: the performance trigger includes one or more of the following items: beam failure for at least one beam in the current beam pair, beam performance below a threshold performance level for the current beam pair, beam quality measurement below a threshold quality level for at least one beam in the current beam pair, or self-interference measurement above a threshold interference level for the current beam pair.

[0124] In aspect 10, the method according to any one of aspects 1-9 also includes: the performance trigger is based on a beam quality measurement including at least one of the following items: a reference signal received power (RSRP) for a reference signal, a signal to interference plus noise ratio (SINR) for the reference signal, or a block error rate (BLER) for at least one beam in the current beam pair.

[0125] In aspect 11, the method according to aspect 10 also includes: the reference signal includes at least one of the following: a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), a positioning reference signal (PRS) or a synchronization signal block (SSB).

[0126] In aspect 12, the method according to aspect 10 further comprises signaling to a second wireless device that the beam quality measurement does not exceed the threshold quality level.

[0127] In aspect 13, the method according to aspect 10 further comprises: receiving an indication from the second wireless device to use the fallback full-duplex beam pair, wherein the first wireless device uses the fallback full-duplex beam pair based at least in part on the indication.

[0128] In aspect 14, the method according to any one of aspects 1-13 further comprises: determining the fallback full-duplex beam pair based on the current beam pair.

[0129] In aspect 15, the method according to any one of aspects 1-14 further includes: the performance trigger is based on a communication error.

[0130] In aspect 16, the method according to any one of aspects 1-15 further comprises: the occurrence of the communication error is based on the reception or transmission of a negative acknowledgement (NACK).

[0131] In aspect 17, the method according to any one of aspects 1-16 also includes: the first wireless device uses the fallback full-duplex beam pair for one or more of the following: a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

[0132] In aspect 18, the method according to any one of aspects 1-17 further includes: the first wireless device using the fallback full-duplex beam pair instead of continuing to use the current beam pair.

[0133] In aspect 19, the method according to any one of aspects 1-18 further includes: the first wireless device continues to use the current beam pair and uses the fallback full-duplex beam pair.

[0134] In aspect 20, the method according to any one of aspects 1-19 further comprises: the first wireless device using the current beam pair and the fallback full-duplex beam pair for duplicate communication.

[0135] In aspect 21, the method according to any one of aspects 1-19 further includes: the first wireless device uses a multiplexing scheme to communicate on the current beam pair and the fallback full-duplex beam pair.

[0136] In aspect 22, the method according to any one of aspects 1-21 further includes: the first wireless device comprises a user equipment (UE), and the second wireless device comprises a base station or an integrated access and backhaul (IAB) node.

[0137] In aspect 23, the method according to any one of aspects 1-22 further includes: the first wireless device comprises an integrated access and backhaul (IAB) node, and the second wireless device comprises a parent IAB node.

[0138] Aspect 24 is a device comprising: one or more processors; and one or more memories in electronic communication with the one or more processors, storing instructions that can be executed by the one or more processors to cause the system or device to implement a method as in any of aspects 1 to 23.

[0139] Aspect 25 is a system or an apparatus, comprising: a unit for implementing a method as in any of aspects 1 to 23 or implementing an apparatus as in any of aspects 1 to 23.

[0140] Aspect 26 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement the method as in any of aspects 1 to 23.

[0141] Aspect 27 is a method of wireless communication at a first wireless device, comprising: receiving an indication of the occurrence of a performance trigger for a current beam pair for full-duplex communication from a second wireless device; and in response to receiving the indication, communicating with the second wireless device using a fallback full-duplex beam pair.

[0142] In aspect 28, the method according to aspect 27 further comprises: receiving a self-interference measurement from the second wireless device or performing the self-interference measurement; and switching from the fallback full-duplex beam pair to a new beam pair based on the self-interference measurement.

[0143] In aspect 29, the method according to aspect 27 or aspect 28 further comprises: prior to receiving the indication of the occurrence of the performance trigger, indicating the fallback full-duplex beam pair to the second wireless device.

[0144] In aspect 30, the method according to any one of aspects 27-29 also includes: the fallback full-duplex beam pair is indicated by one or more of the following: an uplink beam identifier (ID) for the uplink beam in the fallback full-duplex beam pair, a downlink beam ID for the downlink beam in the fallback full-duplex beam pair, a beam pair ID for the fallback full-duplex beam pair, or a TCI code point mapped to the uplink and downlink transmission configuration indicator (TCI) states for the fallback full-duplex beam pair.

[0145] In aspect 31, the method according to any one of aspects 27-30 also includes: the indication is indicated in one or more of the following: downlink control information (DCI), medium access control-control element (MAC-CE), or radio resource control (RRC) signaling.

[0146] In aspect 32, the method according to any one of aspects 27-31 further comprises: determining the fallback full-duplex beam pair based on a rule.

[0147] In aspect 33, the method according to aspect 32 further comprises: the rule is based on at least one of a subset of reported full-duplex beam pairs or the current beam pair.

[0148] In aspect 34, the method of aspect 32 further comprises: the rule being defined or sent to the second wireless device.

[0149] In aspect 35, the method according to any one of aspects 27-34 also includes: the performance trigger is one or more of the following: beam failure for at least one beam in the current beam pair, beam performance below a threshold performance level for the current beam pair, beam quality measurement below a threshold quality level for at least one beam in the current beam pair, or self-interference measurement above a threshold interference level for the current beam pair.

[0150] In aspect 36, the method according to any one of aspects 27-35 also includes: the performance trigger is based on a beam quality measurement including at least one of the following items: a reference signal received power (RSRP) for a reference signal, a signal to interference plus noise ratio (SINR) for the reference signal, or a block error rate (BLER) for at least one beam in the current beam pair.

[0151] In aspect 37, the method according to any one of aspects 27-36 also includes: the reference signal includes at least one of the following: a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), a positioning reference signal (PRS) or a synchronization signal block (SSB).

[0152] In aspect 38, the method according to any of aspects 27-37 further comprises instructing the second wireless device to use the fallback full-duplex beam pair in response to receiving the indication of the occurrence of the performance trigger.

[0153] In aspect 39, the method according to any one of aspects 27-38 further comprises: determining the fallback full-duplex beam pair based on the current beam pair.

[0154] In aspect 40, the method according to any one of aspects 27-39 further includes: the first wireless device using the fallback full-duplex beam pair instead of continuing to use the current beam pair.

[0155] In aspect 41, the method according to any of aspects 27-40 further includes: the first wireless device continues to use the current beam pair and uses the fallback full-duplex beam pair.

[0156] In aspect 42, the method according to aspect 41 further comprises: the first wireless device using the current beam pair and the fallback full-duplex beam pair for duplicate communication.

[0157] In aspect 43, the method according to aspect 41 further comprises: the first wireless device uses a multiplexing scheme to communicate on the current beam pair and the fallback full-duplex beam pair.

[0158] In aspect 44, the method according to any one of aspects 27-43 further includes: the first wireless device comprises a base station or an integrated access and backhaul (IAB) node, and the second wireless device comprises a user equipment (UE).

[0159] In aspect 45, the method according to any one of aspects 27-44 further includes: the first wireless device comprises a parent integrated access and backhaul (IAB) node, and the second wireless device comprises a child IAB node.

[0160] Aspect 46 is a device comprising: one or more processors; and one or more memories in electronic communication with the one or more processors, storing instructions that can be executed by the one or more processors to cause the system or device to implement a method as in any of aspects 27 to 45.

[0161] Aspect 47 is a system or an apparatus, comprising: a unit for implementing a method as in any of Aspects 27 to 45 or implementing an apparatus as in any of Aspects 27 to 45.

[0162] Aspect 48 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement a method as in any of Aspects 27 to 45.

[0163] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged based on design preferences. In addition, some blocks can be combined or omitted. The attached method claims provide the elements of each block in an exemplary order and are not intended to be limited to the specific order or hierarchy provided.

[0164] The foregoing description is provided so that any person skilled in the art can implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but to be given the full scope consistent with the language claims, wherein, unless explicitly stated as such, reference to singular elements is not intended to mean "one and only one", but "one or more". Terms such as "if", "when ..." and "while ..." should be interpreted as "under the condition of ...", rather than meaning an immediate time relationship or reaction. That is, these phrases (e.g., "when ...") do not mean immediate action in response to the occurrence of an action or during the occurrence of an action, but only mean that the action will occur if the condition is met, but do not require a specific or immediate time constraint for the occurrence of the action. The word "exemplary" is used herein to mean "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred to or having advantages over other aspects. Unless otherwise expressly stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. The words “module,” “mechanism,” “element,” “device,” etc. may not be substitutes for the word “unit.” Thus, no claim element should be interpreted as a functional unit unless the element is explicitly recited using the phrase “a means for….”

Claims

1. A method of wireless communication at a first wireless device, comprising: receiving, prior to occurrence of a performance trigger for the current beam pair, an indication to fall back to the full-duplex beam pair from a second wireless device; determining said occurrence of said performance trigger for said current beam pair; switching from the current beam pair to the fallback full-duplex beam pair for full-duplex communication at the first wireless device based at least in part on the occurrence of the performance trigger; responsive to determining said occurrence of said performance trigger, performing a self-interference measurement to determine a new beam pair for full-duplex communication; as well as Switching from the fallback full-duplex beam pair to the new beam pair based on the self-interference measurement. 2 . The method of claim 1 , further comprising determining the fallback full-duplex beam pair based on a rule.

3. The method according to claim 2, wherein: The rule is based on at least one of a subset of reported full-duplex beam pairs or the current beam pair.

4. The method according to claim 2, wherein: The rules are defined or received from the second wireless device. 5 . The method of claim 4 , further comprising signaling to the second wireless device that the beam quality measurement does not exceed a threshold quality level.

6. The method of claim 4, further comprising receiving a third indication from the second wireless device to use the fallback full-duplex beam pair, wherein: The first wireless device switches from the current beam pair to the fallback full-duplex beam pair based at least in part on the third indication.

7. The method of claim 1, further comprising determining the fallback full-duplex beam pair based on the current beam pair.

8. A method of wireless communication at a first wireless device, comprising: before receiving a second indication of an occurrence of a performance trigger for a current beam pair, sending a first indication of a fallback full-duplex beam pair to a second wireless device, wherein the occurrence of the performance trigger triggers a switch from the current beam pair to the fallback full-duplex beam pair; receiving, from the second wireless device, the second indication of the occurrence of the performance trigger for the current beam pair; In response to receiving the second indication, switching from the current beam pair to the fallback full-duplex beam pair for full-duplex communication with the second wireless device; receiving or making self-interference measurements from the second wireless device; and Switching from the fallback full-duplex beam pair to a new beam pair based on the self-interference measurement.

9. The method of claim 8, further comprising sending a third indication to the second wireless device to switch from the current beam pair to the fallback full-duplex beam pair in response to receiving the second indication of the occurrence of the performance trigger.

10. The method of claim 8, further comprising determining the fallback full-duplex beam pair based on the current beam pair.

11. An apparatus for wireless communication, the apparatus being a first wireless device, comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving, prior to occurrence of a performance trigger for the current beam pair, an indication to fall back to the full-duplex beam pair from a second wireless device; determining said occurrence of said performance trigger for said current beam pair; switching from the current beam pair to the fallback full-duplex beam pair for full-duplex communication at the first wireless device based at least in part on the occurrence of the performance trigger; responsive to determining said occurrence of said performance trigger, performing a self-interference measurement to determine a new beam pair for full-duplex communication; and Switching from the fallback full-duplex beam pair to the new beam pair based on the self-interference measurement.

12. The device according to claim 11, wherein The fallback full-duplex beam pair is indicated by one or more of the following: an uplink beam identifier (ID) of an uplink beam in the fallback full-duplex beam pair, a downlink beam ID of a downlink beam in the fallback full-duplex beam pair, The beam pair ID of the fallback full-duplex beam pair, or Uplink and downlink transmission configuration indicator (TCI) states mapped to TCI code points for the fallback full-duplex beam pair.

13. The device according to claim 11, wherein: The instructions are included in one or more of the following: Downlink Control Information (DCI), Medium Access Control - Control Element (MAC-CE), or Radio Resource Control (RRC) signaling.

14. The device according to claim 13, wherein: The first wireless device comprises a user equipment (UE), and the second wireless device comprises a base station or an integrated access and backhaul (IAB) node.

15. The device according to claim 13, wherein: The first wireless device comprises an integrated access and backhaul (IAB) node, and the second wireless device comprises a parent IAB node.

16. The device according to claim 11, wherein The performance trigger includes one or more of the following: A beam failure occurs in at least one beam of the current beam pair, the beam performance of the current beam pair being below a threshold performance level, a beam quality measurement of at least one beam in the current beam pair that is below a threshold quality level, or The self-interference measurement of the current beam pair is above a threshold interference level.

17. The device according to claim 11, wherein: The performance trigger is based on a beam quality measurement comprising at least one of: a reference signal received power (RSRP) of a reference signal, a signal to interference plus noise ratio (SINR) of the reference signal, or a block error rate (BLER) of at least one beam in the current beam pair.

18. The device according to claim 17, wherein: The reference signal includes at least one or more of the following: a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), a positioning reference signal (PRS), or a synchronization signal block (SSB).

19. The device according to claim 11, wherein: The performance trigger is based on a communication error.

20. The device according to claim 19, wherein The communication error occurs based on the reception or transmission of a negative acknowledgement (NACK).

21. The device according to claim 11, wherein The first wireless device uses the fallback full-duplex beam pair for one or more of: a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), or a physical uplink control channel (PUCCH).

22. The device according to claim 11, wherein The first wireless device uses the fallback full-duplex beam pair instead of continuing to use the current beam pair.

23. The device according to claim 11, wherein: The first wireless device continues to use the current beam pair along with using the fallback full-duplex beam pair.

24. The device according to claim 11, wherein The first wireless device uses the current beam pair and the fallback full-duplex beam pair for duplicate communication.

25. The device according to claim 11, wherein The first wireless device communicates on the current beam pair and the fallback full-duplex beam pair using a multiplexing scheme.

26. An apparatus for wireless communication at a first wireless device, the apparatus comprising: Memory; as well as at least one processor coupled to the memory and configured to: before receiving a second indication of an occurrence of a performance trigger for a current beam pair, sending a first indication of a fallback full-duplex beam pair to a second wireless device, wherein the occurrence of the performance trigger triggers a switch from the current beam pair to the fallback full-duplex beam pair; receiving, from the second wireless device, the second indication of the occurrence of the performance trigger for the current beam pair; In response to receiving the second indication, switching from the current beam pair to the fallback full-duplex beam pair for full-duplex communication with the second wireless device; receiving or making self-interference measurements from the second wireless device; and Switching from the fallback full-duplex beam pair to a new beam pair based on the self-interference measurement.

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