Initial beam sweeping for smart directional repeaters

Abstract

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for enhancing the functionality of directional repeaters (e.g., wireless devices that relay directional wireless signals). By adding even limited capabilities within directional repeaters to buffer digital samples, the functionality of directional repeaters can be enhanced to provide better coverage and more efficiently utilize time, frequency, and space resources.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 17 / 002,576, filed on August 25, 2020, which claims the benefit of and priority to U.S. Provisional Patent Application No. 62 / 892,519, filed on August 27, 2019, the entire contents of both applications are hereby incorporated by reference herein.

[0003] background

[0004] Public domain

[0005] Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for coordinating beams used by a base station (BS) and a directional repeater, for example, to transmit and receive acquisition-related signaling such as synchronization signal blocks (SSBs).

[0006] Related technical description

[0007] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, 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, to name just a few.

[0008] In some examples, a wireless multiple access communication system may include several base stations (BSs), each of which is capable of simultaneously supporting communication of multiple communication devices (also referred to as user equipment (UE)). In an LTE or LTE-A network, a set of one or more BSs may define an evolved Node B (eNB). In other examples (e.g., in a next generation, new radio (NR), or 5G network), a wireless multiple access communication system may include several distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) in communication with several central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), wherein a set of one or more DUs in communication with a CU may define an access node (e.g., which may be referred to as a BS, a 5G NB, a next generation Node B (gNB or gNodeB), a transmission reception point (TRP), etc.). A BS or DU may communicate with a set of UEs on downlink channels (eg, for transmissions from the BS or DU to the UEs) and uplink channels (eg, for transmissions from the UEs to the BS or DU).

[0009] 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. NR (e.g., New Radio or 5G) is an example of an emerging telecommunication standard. NR is an enhancement set of the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0010] However, as the demand for mobile broadband access continues to grow, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunication standards that employ these technologies.

[0011] Overview

[0012] The systems, methods, and devices of the present disclosure each have several aspects, no single aspect of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed in the appended claims, some features will now be briefly discussed. After considering this discussion, and especially after reading the section entitled "Detailed Description," it will be understood how the features of the present disclosure provide advantages that may include desired communications in an integrated access and backhaul (IAB) system.

[0013] Certain aspects provide a method for wireless communication by a wireless device. The method generally includes: determining a first set of one or more beams for receiving a synchronization signal block (SSB) from a base station (BS); determining a second set of one or more beams for transmitting the SSB received via the first set of one or more beams; and relaying the SSB from the BS to at least one second wireless device using the first set of one or more beams and the second set of one or more beams.

[0014] Certain aspects provide a method for wireless communication by a BS. The method generally includes: determining a first set of one or more beams for transmitting an SSB to at least a first wireless device for relaying by the first wireless device to a second wireless device via a second set of one or more beams; and transmitting the SSB to the first wireless device using the first set of one or more beams.

[0015] Certain aspects provide an apparatus for wireless communication by a first wireless device. The apparatus may include at least one processor and a memory. The at least one processor and the memory may be configured to: determine a first set of one or more beams for receiving an SSB from a BS. The at least one processor and the memory may be further configured to: determine a second set of one or more beams for transmitting an SSB received via the first set of beams. The at least one processor and the memory may be further configured to: relay the SSB from the BS to at least one second wireless device using the first set of one or more beams and the second set of one or more beams.

[0016] Certain aspects provide an apparatus for wireless communication by a BS. The apparatus may include at least one processor and a memory. The at least one processor and the memory may be configured to: determine a first set of one or more beams for transmitting an SSB to at least a first wireless device to be relayed by the first wireless device to a second wireless device via a second set of one or more beams. The at least one processor and the memory may be further configured to: transmit the SSB to the first wireless device using the first set of one or more beams.

[0017] Aspects of the present disclosure also provide various apparatuses, devices, and computer-readable media for (or capable of) performing the operations described above.

[0018] To achieve the foregoing and related ends, one or more aspects include features fully described below 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 only indicative of several of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to understand in detail the manner in which the above-stated features of the present disclosure are used, a more particular description of the content briefly summarized above may be made with reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0021] Figure 1 is a block diagram conceptually illustrating an example wireless system in accordance with certain aspects of the present disclosure.

[0022] Figure 2 is a block diagram conceptually illustrating an example architecture of a distributed radio access network (RAN) in accordance with certain aspects of the present disclosure.

[0023] Figure 3 Illustrated are example components of a base station (BS) and user equipment (UE) in accordance with certain aspects of the present disclosure.

[0024] Figure 4 is a block diagram illustrating an example communication protocol stack in a RAN in accordance with certain aspects of the present disclosure.

[0025] Figure 5 is a block diagram illustrating an example of a frame format for New Radio (NR) in accordance with certain aspects of the present disclosure.

[0026] Figure 6 is a block diagram of an example wireless system deploying repeaters in which aspects of the present disclosure may be performed.

[0027] Fig. 7A and Figure 7B Example scenarios are explained in which aspects of the present disclosure may be implemented.

[0028] Figure 8 is a block diagram of an example architecture for a directional repeater.

[0029] Fig. 9 is a block diagram of an example architecture for a directional repeater in accordance with certain aspects of the present disclosure.

[0030] Fig.10 Illustrated are example operations that may be performed by a directional repeater in accordance with certain aspects of the present disclosure.

[0031] Fig.11 Example operations that may be performed by a BS in accordance with certain aspects of the present disclosure are illustrated.

[0032] Fig.12 One option for initial beam sweeping between a BS and a relay is illustrated in accordance with certain aspects of the present disclosure.

[0033] Fig.13

[0066] Another option for initial beam sweeping between a BS and a relay is illustrated in accordance with certain aspects of the present disclosure.

[0034] Fig.14

[0066] Yet another option for initial beam sweeping between a BS and a relay is illustrated in accordance with certain aspects of the present disclosure.

[0035] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation.

[0036] Detailed Description

[0037] Various aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for performing initial beam sweeping of transmissions between a base station (BS) and one or more directional repeaters (e.g., one or more wireless devices that can relay directional wireless signals), which are considered to be enhanced (or "smart") relative to conventional repeaters (which are essentially limited to receiving, amplifying, and relaying radio frequency (RF) signals). In one aspect, initial beam sweeping of transmissions between a BS and one or more directional repeaters is performed so that a first repeater in the one or more directional repeaters can use a single wide beam to transmit a swept synchronization signal block (SSB) from the BS. This technique can be performed when the angular space covered by the first repeater is limited. On the other hand, initial beam sweeping of transmissions between a BS and one or more directional repeaters is performed so that a second repeater in the one or more directional repeaters can time division multiplex (TDM) its SSB sweep with the SSB sweep of the BS in a coordinated manner with the BS. This technique can provide a high degree of flexibility. In yet another aspect, an initial beam sweep of a transmission between a BS and one or more directional repeaters is performed such that a third one of the one or more directional repeaters can select one or more SSBs from the BS and can sweep only during those transmissions. The technique can achieve a reduced amount of overhead through some ability of the third repeater to sweep.

[0038] The following description provides an example of a technique for coordinating beams used by a BS and one or more directional repeaters, without limiting the scope, applicability, or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements discussed without departing from the scope of the present disclosure. Various examples may appropriately omit, replace, or add various procedures or components. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Moreover, the features described with reference to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functionality, or structures and functionality as a supplement to the various aspects of the present disclosure set forth herein or in addition. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of the claims. The wording "exemplary" is used herein to mean "used as an example, instance, or explanation". Any aspect described as "exemplary" herein is not necessarily to be interpreted as superior to or superior to other aspects.

[0039] The techniques described herein can be used for various wireless communication technologies, such as long term evolution (LTE), code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier FDMA (SC-FDMA) and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio technologies such as New Radio (NR) (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDMA, etc. UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS).

[0040] NR is an emerging wireless communication technology being developed in collaboration with the 5G Technology Forum (5GTF). The third generation partnership project (3GPP) LTE and advanced LTE (LTE-A) are UMTS versions that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named 3GPP. CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For the sake of clarity, although various aspects may be described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied in communication systems based on other generations, such as 5G and later generations, including NR technologies.

[0041] NR access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or higher), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or higher), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical services targeting ultra-reliable low latency communication (URLLC). These wireless communication services may include latency and reliability requirements. These wireless communication services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these wireless communication services can coexist in the same subframe.

[0042] The teachings herein may be incorporated into (eg, implemented within or performed by) a variety of wired or wireless devices (eg, nodes). In some aspects, a wireless node implemented according to the teachings herein may include an access point (AP) or an access terminal (AT).

[0043] An AP may include, be implemented as, or be referred to as a Node B (NB), a Radio Network Controller (RNC), an evolved Node B (eNB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a Base Station (BS), a Transceiver Function (TF), a Radio Router, a Radio Transceiver, a Basic Service Set (BSS), an Extended Service Set (ESS), a Radio Base Station (“RBS”), an Integrated Access and Backhaul (IAB) node (e.g., an IAB donor node, an IAB parent node, and an IAB child node), or some other terminology.

[0044] AT may include, be implemented as, or be referred to as a subscriber station, a subscriber unit, a mobile station, a remote station, a remote terminal, a user terminal, a user agent, a user device, a user equipment (UE), a user station, or some other term. In some implementations, AT may include a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless connection capability, a station (STA), or some other suitable processing device (such as an augmented reality (AR) / virtual reality (VR) console and a head-mounted device) connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or a smart phone), a computer (e.g., a laptop computer), a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. In some aspects, a node is a wireless node. Such a wireless node may provide connectivity for or to a network (eg, a wide area network such as the Internet or a cellular network), for example, via a wired or wireless communication link.

[0045] Example Wireless Communication System

[0046] Figure 1 An example wireless communication network 100 is illustrated in which aspects of the present disclosure may be performed. Figure 1 As shown in FIG. 1 , BS 110a may include an initial beam sweep module 122 that may be designed and configured to sweep across a set of beams when transmitting an SSB to repeater 110r. As illustrated, repeater 110r may also have an initial beam sweep module 124, for example, to process (e.g., receive and relay) the SSB transmitted by BS 110a during the initial beam sweep. In some cases, repeater 110r and BS 110a may be configured to perform each of the following operations: Fig.10 and Fig.11 Operations 1000 and 1100.

[0047] For example, the wireless communication network 100 may be a NR or 5G network. Figure 1As illustrated in , the wireless communication network 100 may include several BSs (or APs) 110a-z (each also individually referred to herein as AP 110 or collectively referred to herein as AP 110) and other network entities. AP 110 may be a station that communicates with UE 120a-y (each also individually referred to herein as UE 120 or collectively referred to herein as UE 120). Each AP 110 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a NB and / or a NB subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the term "cell" and next generation NB (e.g., gNB or gNodeB), NR AP, 5G NB, or transmit reception point (TRP) may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of ​​the cell may move depending on the location of the mobile AP 110. In some examples, APs 110 may be interconnected to each other and / or to one or more other APs 110 or network nodes (not shown) in wireless communication network 100 via various types of backhaul interfaces, such as direct physical connections, wireless connections, virtual networks, or the like using any suitable transport network.

[0048] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as radio technology, air interface, etc. Frequency may also be referred to as carrier, subcarrier, frequency channel, frequency modulation, subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0049] The AP 110 may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs 120 associated with the femto cell (e.g., UEs 120 in a closed subscriber group (CSG), UEs 120 of users in a residence, etc.). An AP for a macro cell may be referred to as a macro AP. An AP 110 for a pico cell may be referred to as a pico AP. An AP 110 for a femto cell may be referred to as a femto AP or a home AP. In Figure 1, APs 110a, 110b, and 110c may be macro APs for macro cells 102a, 102b, and 102c, respectively. AP 110x may be a pico AP for pico cell 102x. APs 110y and 110z may be femto APs for femto cells 102y and 102z, respectively. AP 110 may support one or more (e.g., three) cells.

[0050] The wireless communication network 100 may also include a relay station. A relay station is a station that receives transmissions of data and / or other information from an upstream station (e.g., an AP 110 or a UE 120) and sends transmissions of the data and / or other information to a downstream station (e.g., a UE 120 or an AP 110). A relay station may also be a UE 120 that relays transmissions for other UEs 120. Figure 1 In the example shown in , a relay station may communicate with AP 110a and UE 120r to facilitate communication between AP 110a and UE 120r. A relay station may also be referred to as an IAB node, relay AP, relay, and the like.

[0051] The wireless communication network 100 may be a heterogeneous network including different types of APs 110 (e.g., macro APs, pico APs, femto APs, relays, etc.). These different types of APs 110 may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless communication network 100. For example, a macro AP may have a high transmit power level (e.g., 20 Watts), while pico APs, femto APs, and relays may have lower transmit power levels (e.g., 1 Watt).

[0052] The wireless communication network 100 may support synchronous or asynchronous operation. For synchronous operation, each AP 110 may have similar frame timing, and transmissions from different APs 110 may be approximately aligned in time. For asynchronous operation, each AP 110 may have different frame timing, and transmissions from different APs 110 may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operation.

[0053] A network controller 130 may couple to a set of APs 110 and provide coordination and control for the APs 110. The network controller 130 may communicate with the APs 110 via a backhaul. The APs 110 may also communicate with each other (eg, directly or indirectly) via a wireless or wired backhaul.

[0054] UE 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. UE 120 may also be referred to as a mobile station, terminal, AT, subscriber unit, station, customer premises equipment (CPE), cellular phone, smart phone, PDA, wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, WLL station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or medical equipment, biometric sensor / device, wearable device (such as smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart necklace, etc.)), entertainment device (e.g., music device, video device, satellite radio, etc.), transportation component or sensor, smart meter / sensor, industrial manufacturing equipment, global positioning system device, or any other suitable device configured to communicate via wireless or wired medium. Some UEs may be considered as machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs may include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with AP 110, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity to or to a network (e.g., a wide area network (such as the Internet) or a cellular network), for example, via a wired or wireless communication link. Some UEs 120 may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0055] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the DL and single carrier frequency division multiplexing (SC-FDM) on the UL. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also often referred to as frequency modulation, frequency bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain for OFDM and in the time domain for SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the spacing of the subcarriers can be 15kHz, and the minimum resource allocation (called a "resource block" (RB)) can be 12 subcarriers (or 180kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0056] Although aspects of the examples described herein may be associated with LTE technology, aspects of the present disclosure may be applicable to other wireless communication systems, such as NR. NR may utilize OFDM with CP on the uplink and downlink, and include support for half-duplex operation using time division duplex (TDD). Beamforming may be supported and the beam direction may be dynamically configured. Multiple-input multiple-output (MIMO) transmissions with precoding may also be supported. The MIMO configuration in the DL may support up to 8 transmit antennas (with multi-layer DL transmissions of up to 8 streams) and up to 2 streams per UE 120. Multi-layer transmissions of up to 2 streams per UE 120 may be supported. Aggregation of multiple cells may be supported using up to 8 serving cells.

[0057] In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., AP 110) allocates resources for communication between some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, the subordinate entity utilizes the resources allocated by the scheduling entity. AP 110 is not the only entity that can act as a scheduling entity. In some examples, UE 120 may act as a scheduling entity, and may schedule resources for one or more subordinate entities (e.g., one or more other UEs 120), and other UEs 120 may utilize the resources scheduled by the UE 120 for wireless communication. In some examples, UE 120 may act as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In a mesh network example, UE 120 may communicate directly with each other in addition to communicating with the scheduling entity.

[0058] exist Figure 1 , a solid line with double arrows indicates desired transmissions between a UE 120 and a serving AP 110, which is an AP 110 designated to serve the UE 120 on the DL and / or UL. A thin dashed line with double arrows indicates interfering transmissions between the UE 120 and the AP 110.

[0059] Figure 2 An example architecture of a distributed radio access network (RAN) 200 including an example IAB network 250 is illustrated. Figure 1 The wireless communication network 100 described in the embodiment is implemented in FIG. Figure 2 As shown in , the distributed RAN 200 includes a core network (CN) 202 and an access node (AN) configured as an IAB donor 208.

[0060] like Figure 2 As shown in FIG. 1 , the IAB network 250 includes an IAB donor node 208. The IAB donor node 208 is a RAN node (e.g., an access point / gNB that terminates the NR Ng interface with the CN 202 (e.g., the next generation NG core)) and is generally connected to the CN 202 via a wired backhaul link. The CN 202 can host core network functions. The CN 202 can be centrally deployed. The CN 202 functionality can be offloaded (e.g., to Advanced Wireless Services (AWS)) in an effort to handle peak capacity. The CN 202 can include an access and mobility management function (AMF) 204 and a user plane function (UPF) 206. The AMF 204 and the UPF 206 can perform one or more CN 202 functions.

[0061] The IAB donor node 208 may communicate with the CN 202 (e.g., via a backhaul interface). The IAB donor node 208 may communicate with the AMF 204 via an N2 (e.g., NG-C) interface. The IAB donor node 208 may communicate with the UPF 206 via an N3 (e.g., NG-U) interface. The IAB donor node 208 may include a central unit control plane (CU-CP) 210, one or more central unit user planes (CU-UP) 212, one or more distributed units (DU) 214, 218, and one or more antenna / remote radio units (AU / RRU) (not shown). The CU and DU may also be referred to as gNB-CU and gNB-DU, respectively.

[0062] The IAB donor node 208 may also be referred to as an IAB anchor node and may include an IAB central unit (e.g., NR CU) or an IAB distributed unit (e.g., NR DU). The IAB network 250 further includes one or more non-donor IAB nodes (e.g., 220a-220e). Each IAB node (including donor and non-donor IAB nodes) may serve one or more UEs (e.g., 222a-222c) connected to the IAB node. As shown, each IAB node (including the donor IAB donor node 208) may be connected via a wireless backhaul link (e.g., an NR wireless backhaul link or a backup NR wireless backhaul link). Each IAB node is connected to the UE it serves via a corresponding access link.

[0063] Each IAB node is a RAN node (e.g., an access point / gNB) that provides IAB functionality with two roles, including a data unit function (DU-F) and a mobile termination function (MT-F). The DU-F of an IAB node is generally responsible for scheduling UEs (e.g., UEs served by the IAB node) and other IAB nodes (e.g., other IAB nodes connected to the IAB node as child nodes). The DU-F also controls both the access and backhaul links under its coverage. The MT-F of an IAB node is controlled and scheduled by the IAB donor node 208 or another IAB node as its parent IAB node. In one aspect, the IAB donor node 208 includes only the DU-F and not the MT-F.

[0064] The CU-CP 210 may be connected to one or more of the DUs 214 and 218. The CU-CP 210 and the DUs 214 and 218 may be connected via a wired interface using the F1-C protocol. Figure 2 As shown in FIG, CU-CP 210 may be connected to multiple DUs, but DUs 214 and 218 may be connected to only one CU-CP. Figure 2Only one CU-UP 212 is illustrated, but the IAB donor node 208 may include multiple CU-UPs. The CU-CP 210 selects the appropriate CU-UP(s) for the requested service (e.g., for the UE). The CU-UP(s) 212 may be connected to the CU-CP 210. For example, the CU-UP(s) 212 and the CU-CP 210 may be connected via an E1 interface. The CU-CP(s) 212 may be connected to one or more of the DUs 214, 218. The CU-UP(s) 212 and the DUs 214, 218 may be connected via an F1-U interface. Figure 2 As shown in , the CU-CP 210 may be connected to a plurality of CU-UPs, but each CU-UP may be connected to only one CU-CP.

[0065] A DU (such as DU 214 and / or 218) may host one or more transmit / receive points (TRPs, which may include edge nodes (ENs), edge units (EUs), radio heads (RHs), smart radio heads (SRHs), etc.). A DU may be located at the edge of a network with radio frequency (RF) functionality. DUs 214, 216 may be connected to multiple CU-UPs 212, which are connected to the same CU-CP (e.g., under the control of the same CU-CP) (e.g., for RAN sharing, radio as a service (RaaS), and service-specific deployments). DUs 214, 216 may be configured to serve traffic to UEs individually (e.g., dynamically selected) or jointly (e.g., joint transmission). Each DU 214, 218 may be connected to one of the AU / RRUs.

[0066] The CU-CP 210 may be connected to multiple DUs 214, 218 that are connected to the same CU-UP 212 (e.g., under the control of the same CU-UP 212). Connectivity between the CU-UP 212 and the DUs 214, 218 may be established by the CU-CP 210. For example, a bearer context management function may be used to establish connectivity between the CU-UP 212 and the DUs 214, 218. Data forwarding between the CU-UPs 212 may be via an Xn-U interface.

[0067] The distributed RAN 200 may support forward haul solutions across different deployment types. For example, the distributed RAN 200 architecture may be based on transport network capabilities (e.g., bandwidth, latency, and / or jitter). The distributed RAN 200 may share features and / or components with LTE. For example, the IAB donor node 208 may support dual connectivity with NR and may share a common forward haul for LTE and NR. The distributed RAN 200 may enable collaboration between and among DUs 214, 218, for example, via the CU-CP 212. Inter-DU interfaces may not be used.

[0068] The various logical functions may be dynamically distributed in the distributed RAN 200. Figure 4 Described in more detail, the RRC layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer, the physical (PHY) layer and / or the RF layer may be adaptively placed at the AN and / or the UE.

[0069] Figure 3 Explanation (such as Figure 1 10 and UE 120) may be used to implement aspects of the present disclosure. For example, antenna 352, processors 366, 358, 364, and / or controller / processor 380 of UE 120 and / or antenna 334, processors 320, 330, 338, and / or controller / processor 340 of AP 110 may be used to perform the various techniques and methods described herein. For example, Figure 3 As shown in , the processor 340 includes a full-duplex (FD) time slot configuration circuit 290; according to various aspects described herein, the FD time slot configuration circuit 290 can be configured for full-duplex time slot configuration in the IAB communication system. In some aspects, the FD time slot communication circuit 290 enables the processor 340 to detect changes in one or more traffic parameters and dynamically modify the time slot mode based on the changes in the one or more traffic parameters. In some aspects, the AP 110 can be an IAB donor node, a parent node, or an IAB child node.

[0070] At the AP 110, the transmit processor 320 may receive data from the data source 312 and control information from the controller / processor 340. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. The processor 320 may process (e.g., encode and symbol map) the data and the control information to obtain data symbols and control symbols, respectively. The transmit processor 320 may also generate reference symbols (e.g., reference symbols for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS)). The transmit MIMO processor 330 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, where applicable, and may provide output symbol streams to modulators (MODs) 332a to 332t. Each MOD 332 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each MOD may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. The DL signals from MODs 332a to 332t may be transmitted via antennas 334a to 334t, respectively.

[0071] At the UE 120, antennas 352a to 352r may receive DL signals from the AP 110 and may provide received signals to demodulators (DEMODs) 354a to 354r in the transceiver, respectively. Each DEMOD 354 in the transceiver may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each DEMOD 354 in the transceiver may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 356 may obtain received symbols from all DEMODs 354a to 354r in the transceiver, perform MIMO detection on the received symbols where applicable, and provide detected symbols. A receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 360, and provide decoded control information to a controller / processor 380.

[0072] On the UL, at the UE 120, a transmit processor 364 may receive and process data from a data source 362 (e.g., data for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 380 (e.g., control information for a physical uplink control channel (PUCCH)). The transmit processor 364 may also generate reference symbols for a reference signal (e.g., a sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366, if applicable, further processed by DEMODs 354a to 354r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the AP 110. At the AP 110, the UL signal from the UE 120 may be received by the antenna 334, processed by the MOD 332, detected by the MIMO detector 336, if applicable, and further processed by the receive processor 338 to obtain decoded data and control information sent by the UE 120. Receive processor 338 may provide decoded data to data sink 339 and decoded control information to controller / processor 340 .

[0073] Controllers / processors 340 and 380 may direct the operations at AP 110 and UE 120, respectively. Processor 340 and / or other processors and modules at AP 110 may perform or direct the execution of processes for the techniques described herein. Memories 342 and 382 may store data and program codes for AP 110 and UE 120, respectively. Scheduler 344 may schedule UEs for data transmission on the DL and / or UL.

[0074] Figure 4 The illustration shows an example of a communication protocol stack 400 for implementing a RAN (for example, such as RAN 200) according to various aspects of the present disclosure. The communication protocol stack 400 may be implemented in a wireless communication system (such as a 5G NR system (e.g., Figure 1 The layers of the communication protocol stack 400 may be implemented as separate software modules, parts of a processor or an application specific integrated circuit (ASIC), parts of non-co-located devices connected by a communication link, or various combinations thereof. Co-located and non-co-located implementations may be used, for example, in a protocol stack for a network access device or UE. Figure 4 As shown in FIG. 4 , a wireless communication system may support various services 402 on one or more protocols. One or more protocol layers of the communication protocol stack 400 may be provided by an AN (e.g., Figure 2 AN 208 in or Figure 1 The AP 110a) and / or UE (e.g., UE 120) are implemented in the embodiment.

[0075] like Figure 4 As shown in FIG. 4 , the communication protocol stack 400 is split in the AN. The RRC layer 405, the PDCP layer 410, the RLC layer 415, the MAC layer 420, the PHY layer 425, and the RF layer 430 may be implemented by the AN. For example, the CU-CP (e.g., Figure 2 210) and CU-UP (e.g., Figure 2 CU-UP 212 in the example) can each implement the RRC layer 405 and the PDCP layer 410. DU (e.g., Figure 2 DUs 214 and 218 in the DU may implement RLC layer 415 and MAC layer 420. However, DU may also implement PHY layer(s) 425 and RF layer(s) 430 via AU / RRU connected to the DU. PHY layer 425 may include a high PHY layer and a low PHY layer.

[0076] A UE (eg, UEs 222a - 222c ) may implement the entire communication protocol stack 400 (eg, RRC layer 405 , PDCP layer 410 , RLC layer 415 , MAC layer 420 , PHY layer(s) 425 , and RF layer(s) 430 ).

[0077] Figure 5 5 is a diagram showing an example of a frame format 500 for NR. The transmission timeline of each of DL and UL may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be divided into 10 subframes with indices 0 to 9, each subframe being 1 ms. Each subframe may include a variable number of slots, depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. An index may be assigned to the symbol period in each slot. A mini slot (which may be referred to as a subslot structure) refers to a transmission time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols). Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction for each subframe may be dynamically switched. The link direction may be based on the slot format. Each slot may include DL / UL data and DL / UL control information.

[0078] In NR, SSB is transmitted. SSB includes PSS, SSS and two-symbol PBCH. SSB can be transmitted in fixed time slot positions (such as Figure 5) is transmitted in the codewords 0-3 shown in . PSS and SSS can be used by UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identity. PBCH carries some basic system information, such as downlink system bandwidth, timing information within a radio frame, SS burst set periodicity, system frame number, etc. SS blocks can be organized into SS bursts to support beam sweeping. Further system information (such as remaining minimum system information (RMSI), system information blocks (SIBs) (such as system information block type 1 (SIB1)), other system information (OSI)) can be transmitted on PDSCH in certain subframes. SS blocks can be transmitted up to 64 times, for example, up to 64 different beam directions for mmW. Up to 64 transmissions of SS blocks are called SS burst sets. SS blocks in SS burst sets are transmitted in the same frequency region, while SS blocks in different SS burst sets can be transmitted at different frequency positions.

[0079] In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh networks, and / or various other suitable applications. Generally, a sidelink signal may refer to a signal that is communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or AP), even if the scheduling entity may be used for scheduling and / or control purposes. In some examples, the sidelink signal may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum).

[0080] The UE may operate in various radio resource configurations, including a configuration associated with transmitting a pilot using a dedicated resource set (e.g., an RRC dedicated state, etc.), or a configuration associated with transmitting a pilot using a shared resource set (e.g., an RRC shared state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated resource set for transmitting a pilot signal to the network. When operating in the RRC shared state, the UE may select a shared resource set for transmitting a pilot signal to the network. In either case, the pilot signal transmitted by the UE may be received by one or more network access devices (such as an AN, or a DU, or parts thereof). Each receiving network access device may be configured to receive and measure a pilot signal transmitted on a shared resource set, and also receive and measure a pilot signal transmitted on a dedicated resource set allocated to the UE, wherein the network access device is a member of a monitoring network access device set for the UE. One or more receiving network access devices or a CU to which the receiving network access device transmits pilot signal measurements may use these measurements to identify the UE's serving cell or initiate a change in the serving cell for one or more UEs.

[0081] Example Directional Repeater

[0082] The next generation (5G) wireless networks have stated the goal of providing ultra-high data rates and supporting a wide range of application scenarios. The IAB system has been studied in 3GPP as a possible solution to help support these goals.

[0083] As mentioned above, in the IAB system, a wireless backhaul solution is adopted to connect the cellular cells (IAB nodes) to the core network (which uses wired backhaul). Some attractive features of the IAB system are support for multi-hop wireless backhaul, sharing the same technology (e.g., NR) and resources (e.g., frequency band) for both access and backhaul links.

[0084] There are various possible architectures for IAB nodes, including Layer 2 (L2) and Layer 3 (L3) solutions, and the specific architecture deployed may depend on which layers of the protocol stack are implemented in the intermediate node (IAB node), for example, an L2 relay may implement the PHY / MAC / RLC layers.

[0085] Certain aspects of the present disclosure relate to L1 relays (referred to as repeaters). L1 relays / repeaters may have many features. For example, such repeaters are relatively simple, low-cost, low-power, and wirelessly connected to a donor or another relay (e.g., a gNB).

[0086] Figure 6An example application illustrating how repeaters may be used to help improve coverage by overcoming obstructions (e.g., obstruction of RF signals by objects). It is generally understood that obstruction is a major issue in millimeter wave (MMW) where beamforming is used to send directional RF signals. In the illustrated example, repeaters (e.g., r1 602, r2 604, and r3 606) may allow a gNB 608 to serve UEs (e.g., UE1 610 and UE2 612) even if an object blocks the gNB directional RF signal from reaching the UE.

[0087] As illustrated, since r1 602 is not blocked by the object, r1 602 can receive RF signals from gNB 608 and retransmit these RF signals to reach UE1 610 (even though UE1 610 is blocked by the first object 614 and cannot directly receive RF signals from gNB 608). Similarly, since r2 606 is not blocked by the object, r2 606 can receive RF signals from gNB 608 and retransmit these RF signals to reach UE2 612 (even though UE2 612 is blocked by the second object 616 and cannot directly receive RF signals from gNB 608). As demonstrated by this example, L1 repeaters can be used as a relatively simple and inexpensive solution to provide protection against being blocked by objects, extend the coverage of MMW cells, and fill coverage holes.

[0088] Fig. 7A and Figure 7B Additional details are provided on how repeaters can help effectively overcome the challenges of being blocked by one or more objects. Fig. 7A As explained in , a conventional repeater receives an RF signal in one panel (corresponding to a receive or Rx beam) and transmits (retransmits) an RF signal in another panel (corresponding to a transmit or Tx beam). For example, the repeater simply amplifies the received RF signal and forwards the RF signal to become a transmitted RF signal (amplify and forward).

[0089] exist Fig. 7A , repeater r1 702 is capable of receiving RF signals from BS 704 (e.g., during DL) and relaying the RF signals to UE 706, which may be blocked from receiving RF signals directly from BS 704 due to the presence of an object 708 (e.g., a tree) between BS 704 and UE 706. In the other direction (e.g., during UL), repeater r1 702 can receive RF signals from UE 706 and relay the RF signals to BS 704.

[0090] like Figure 7BAs explained in , the repeater r1 702 may include a receiving panel (e.g., a first receiving panel 710 and a second receiving panel 712) and a transmitting panel (e.g., a first transmitting panel 714 and a second transmitting panel 716), which may be used to implement some fixed beam patterns. For wide coverage, the beam pattern is usually wide, so high array gain cannot be achieved. The repeater r1 702 is usually unaware of whether the RF signal is a DL signal or a UL signal in a TDD system and operates in both directions (full duplex) at the same time.

[0091] Figure 8 A schematic diagram illustrating an example architecture 800 for a repeater (e.g., an L1 repeater). As mentioned above, a repeater may receive an analog RF signal on its receiver (RX) antenna (e.g., based on some configured RX beamforming), amplify the power of the received analog RF signal, and transmit the amplified analog RF signal from its transmitter (TX) antenna (e.g., based on some configured TX beamforming).

[0092] As illustrated, beamforming may be accomplished via phased antenna arrays (e.g., first phased antenna array 802 and second phased antenna array 804) configured by controller 806, while amplification may be accomplished via variable gain amplifier 808. The repeater may also communicate some control signals with a server (e.g., a BS acting as a donor, a control node, etc.) via a control interface 810. The control interface 810 may be implemented out-of-band (e.g., operating outside of the carrier frequency on which the RX signal is received) or in-band (e.g., using a smaller bandwidth portion of the same carrier frequency). The out-of-band control interface may be implemented, for example, via a separate (e.g., low-frequency) modem using a different radio technology (e.g., Bluetooth) or a different frequency (e.g., LTE NB-IoT).

[0093] Example initial beam sweep for a smart directional repeater

[0094] Fig. 9 An example architecture 900 for an enhanced repeater (eg, a smart repeater) is shown in accordance with aspects of the present disclosure. As illustrated, the enhanced repeater and Figure 8 The enhanced repeater may have additional components compared to the basic architecture of the present invention, which may allow the enhanced repeater to, for example, optimize beam selection for receiving and / or transmitting RF signals.

[0095] As explained, Fig. 9The enhanced repeater may have components that may allow the enhanced repeater to perform at least limited baseband processing. Such components may include a digital baseband (BB) processor 902 (e.g., having at least limited baseband capabilities relative to a UE or gNB). Components of the enhanced repeater may also include intermediate frequency (IF) stages (e.g., a first IF stage 904 and a second IF stage 906) (which include mixers, filters, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), etc.) designed to convert received RF signals to IF signals, obtain and store digital (IQ) samples, and generate RF signals from the stored digital samples. To this end, the enhanced repeater may include at least sufficient storage space to implement a buffer for storing IQ samples.

[0096] Fig. 9 The enhanced repeater may also include a control interface 908 to receive control signaling from the BS (e.g., to indicate how to store and process digital samples). As described above, the control signaling can be in-band or out-of-band. In the case of in-band control, the digital BB processor 902 can be used to extract control signaling from the received RF signal. In some implementations, the digital BB processor 902 generates the correct branch of the output to the IF stage (e.g., the first IF stage 904 or the second IF stage 906) and sums it with the analog path of the forward link (which may not exist (or be enabled) for the link from the UE to the smart repeater). On the other hand, for the link from the repeater to the gNB, the branch can be used to sum the signal from the UE (and going to the gNB) with any locally generated signals that the smart repeater must send concurrently to the gNB.

[0097] Aspects of the present disclosure provide methods for performing a directive relay from a BS to an enhanced directional repeater (such as the one described above with reference to Fig. 9 As will be described in more detail below, by selecting a first set of one or more beams for receiving these transmissions by the smart repeater and a second set of one or more beams for relaying these transmissions by the smart repeater, acquisition and access procedures involving the smart repeater can be enhanced (relative to Figure 8 ) to provide better coverage and more efficient use of time, frequency, and space resources.

[0098] As mentioned above, in a conventional (baseline) repeater architecture, the data path may be completely analog. In other words, the repeater does not further process the analog RF signal (that must be repeated), but rather forwards the RF signal in its analog form (without any digital BB processing).

[0099] In contrast, a smart repeater can be controlled by a BS (e.g., eNB / gNB) (e.g., in terms of transmit and receive switching and beamforming) to adjust the beam of the smart repeater to beamform to / from a specific UE being served (e.g., steer / direct transmissions to / from that UE). In systems such as 5G, the UEs scheduled at any particular moment are dynamic, which means that the optimal settings for beamforming are also dynamic. For example, the optimal beamforming settings may allow selection of a wider beam, for example, for discovery or acquisition purposes, or selection of a narrower beam to increase antenna gain, received power, and signal-to-noise ratio (SNR).

[0100] The connection establishment procedure in mmWave systems typically starts with the BS sweeping SSB transmissions in different beam directions. The UE typically finds the best beam direction based on how the UE receives the SSBs and uses the known DL / UL beam correspondence information (and reciprocity) to access the wireless communication system.

[0101] For example, each SSB may indicate an index corresponding to the relative (symbol) position of the SSB within the SSB burst. Each SSB index may have a corresponding set of resources to be used for random access channel (RACH) transmissions. Thus, the BS knows what resources to monitor for RACH transmissions, which direction (Rx beam) to listen with; and based on which resources are used, which beam is best for that particular UE.

[0102] Potentially, when directional repeaters are used to extend coverage, a similar type of initial beam sweeping may be beneficial to select the best beam for transmission from both the gNB and the repeater. Ideally, this beam sweeping should be done in a way that is transparent to the UE (which is unaware of the presence of the repeater), maintains DL / UL beam correspondence (between SSB and RACH resources), and is consistent with the normal access procedures followed by legacy UEs.

[0103] Fig.10 and Fig.11 Example operations for performing initial beam sweeping of transmissions from the BS to be relayed by the enhanced directional repeater are explained from the perspective of the enhanced directional repeater and the BS, respectively. In some cases, the BS and the enhanced directional repeater may perform the initial sweeping after or as part of an initial access procedure performed to establish a link between the enhanced directional repeater and the BS.

[0104] Fig.10 1000 for wireless communications by a first wireless device in accordance with certain aspects of the present disclosure. Operations 1000 may be performed, for example, by a repeater (e.g., Figure 1 , 6, any repeater shown in 7, 9 or 12 or any electronic device acting as a repeater) is performed.

[0105] Operations 1000 begin by determining a first set of one or more beams for receiving an SSB from a BS, at 1002. At 1004, a first wireless device determines a second set of one or more beams for transmitting an SSB received via the first set of beams. At 1006, the first wireless device relays the SSB from the BS to at least one second wireless device using the first set of one or more beams and the second set of one or more beams.

[0106] Fig.11 1100 for wireless communications by a BS in accordance with certain aspects of the present disclosure. Operations 1100 may be performed, for example, by Figure 1 , 6 , 7 or 12) to execute any BS / gNB to initialize the enhanced repeater to perform operation 1000.

[0107] Operations 1100 may begin by determining a first set of one or more beams for transmitting SSBs to at least a first wireless device for relaying by the first wireless device to a second wireless device via a second set of one or more beams, at 1102. At 1104, the BS transmits the SSBs to the first wireless device using the first set of one or more beams.

[0108] Figure 12-14 Different solutions for initial beam sweeping that may be used by different repeaters (e.g., smart repeaters) in different scenarios are explained. These solutions are designed to ensure that SSB sweeping (patterns) from the gNB and the repeater occur during the same synchronization signal (SS) burst and match burst by burst in an effort to keep UE operation unaffected (e.g., transparent). The illustrated examples may assume that a gNB-to-relay link has been established, e.g., using an access procedure similar to that used to establish a normal gNB-to-(non-repeater) UE link.

[0109] exist Fig.12 In the first option 1200 illustrated in FIG. 1 , a relay 1202 uses a single wide beam to transmit a swept SSB that the relay 1202 can receive from a gNB 1204. In this example, in each cycle, each of the N SSBs (SS0, SS1, ..., SSN-1) in a block can be sent using a different beam.

[0110] For example, this approach in the first option may be useful when the angular space covered by repeater 1202 is limited. Although wide beams are associated with low antenna gain and corresponding low SNR, this approach in the first option may be feasible due to the high processing gain due to signal design on SSB.

[0111] While a wide beam may be sufficient to relay SSBs, the wide beam may result in insufficient SNR for other access-related messages, such as sending a random access response (RAR). One approach to remedy this scenario is to have the relay 1202 (when transmitting / relaying RAR messages) perform sweeps across multiple narrower beams within the UE RAR window.

[0112] Fig.13 A second option 1300 is illustrated in which one or more repeaters (e.g., a first repeater 1302 and a second repeater 1304) may use TDM for their SSB sweeps with a gNB in ​​a coordinated manner with the gNB. As illustrated, in this case, the SSB cycle may be split, where a regular sweep of N SSBs (SS0, SS1, ..., SSN-1) is followed by a separate period in which the gNB transmits multiple SSBs with the same beam (thus maintaining the same direction), and the one or more repeaters may sweep across a set of beams.

[0113] As illustrated, the gNB may repeat this operation for multiple repeaters (e.g., the first repeater 1302 and the second repeater 1304), each time transmitting multiple SSBs with the same beam directed to the corresponding repeater. For example, the gNB may have determined the best beam for each repeater and use that beam to relay the SSB for each transmitter. This approach allows SSB periodicity to be maintained, which may allow support for legacy devices (e.g., that only expect the first N SSBs). In some cases, the SSB beam from the BS may mandate a different Rx beam at the repeater, rather than maintaining the same Rx beam at the repeater. For example, beam training performed between the one or more repeaters and the BS may indicate such a relationship. In such a case, the one or more repeaters may appropriately set their Rx beams based on which SSB the gNB is transmitting.

[0114] Although Fig.13 The approach shown in increases flexibility and improves link budget (in contrast to Fig.12 ), but this approach comes at the expense of additional resources. For example, in the illustrated example, each repeater uses 2 additional SSB resources (in addition to the regular N SSBs). Furthermore, the more directions the one or more repeaters sweep, the more SSB resources are used. Thus, the second option has limitations in how it scales with additional repeaters per gNB.

[0115] In some cases, space division multiplexing (SDM) can be used as Fig.13, to reduce the amount of time resources required. For example, a BS with multiple panels can transmit SSB in multiple directions at the same time to save resources. Using this approach, multiple repeaters (such as the first repeater 1302 and the second repeater 1304) can sweep (e.g., where panel 1 is used to transmit to repeater 1... and panel N is used to transmit to repeater N).

[0116] Fig.14 A third option 1400 for initial beam sweeping is illustrated, where the first repeater 1402 selects some SSB beams from the gNB and sweeps only during those transmissions. As illustrated, the gNB may perform a regular sweep of only N SSBs per SSB period, while the first repeater 1402 identifies one or more beams from the gNB on which the first repeater 1402 may receive signals, and sweeps in one of its selected beam directions for each instance. This approach results in a reduction in overhead while still providing some ability for the first repeater 1402 to sweep.

[0117] Fig.14 The third option shown in generally avoids the increased overhead caused by the TDM approach, thereby essentially allowing the first repeater 1402 to find one or more beams to use. This approach may not be atypical because often in line-of-sight (LOS) deployed repeaters, even the sidelobes of some beams may be sufficient for this approach (especially since SSB / RACH detection does not require high SNR but may not be suitable for data transmission).

[0118] Although Fig.14 The example shown in shows each repeater (e.g., first repeater 1402 and second repeater 1404) using beams of the same width, but in some cases each repeater may sweep using a mix of wider beams and narrower beams. For example, in some cases each repeater may decide for which gNB beams (SSBs) it should use a wide beam to transmit on its link to the UE, and for which gNB beams it needs the array gain of a narrow beam.

[0119] In some cases, each repeater may take other such actions on its own based on some considerations. For example, each repeater may decide that there are certain SSBs that each repeater does not need to sweep, but can only amplify and forward strong signals (autonomously improving resource utilization).

[0120] Of course, variations of the above approach are possible. For example, the strict correspondence of beam directions across SS bursts may be relaxed in some cases. In other words, while current wireless systems implicitly assume that the beam mapping to SSBs remains the same from SS burst to SS burst, there is no one-to-one correspondence between SS bursts and RACH associated periods. As a result, when a UE sends a RACH transmission, it may not be able to tell on which SS burst it measured the SS RSRP (on which its selection of RACH resources is based).

[0121] In some cases, using in-band control, the gNB may select the Figure 12-14 ) and signals to the relay that it will use that sweep option. In some cases, the gNB and / or relay may select an option and / or select a specific beam set for sweeping based on a number of other factors (e.g., based on a history from which the gNB or relay may learn the placement).

[0122] In some cases, for Fig.13 , the assumption that these repeaters (e.g., the first repeater 1402 and the second repeater 1404) need unique sweeping opportunities may not be necessary. For example, more than one beam may be suitable for the first repeater 1402, so the first repeater 1402 may find that both beams are suitable, so the first repeater 1402 may need to sweep additional beams (so the first repeater 1402 can keep the same beam for TDM).

[0123] In some cases, the repeater may be aware of the RACH association period, and the maximum value may be set to, for example, 160 ms according to the specification. In such cases, the repeater may be allowed to sweep different SS beams across different association periods. In such cases, the repeater may use the most recent beam for RACH reception in the association period.

[0124] The benefits of this approach could be Fig.13 The second option shown in the figure has reduced overhead and covers the use of Fig.14 The third option shown in is the ability to leave possible coverage holes. One potential disadvantage is that the UE behavior may be unknown when the beam changes with a SS burst (e.g., when a repeater changes the beam it sweeps). However, for typical UE operation, there may be minimal degradation.

[0125] After sweeping (relaying) the SSB according to one of the above options, the repeater may monitor RACH transmissions by UEs that detect the (relaying) SSB. The repeater may participate in the RACH procedure, thereby assisting in the exchange of RACH messages between the BS and the UE. If transparency is maintained as required, the UE is unaware of the presence of the repeater and cannot distinguish it from the gNB.

[0126] According to normal RACH operation, the UE may select an SSB with sufficient SS RSRP and transmit the RACH preamble in the RACH opportunity corresponding to that SSB. The repeater may maintain the correspondence of its beam with the beam of the gNB. For example, if the repeater uses Rx beam m and transmits on Tx beam n on the link between the repeater and the gNB for SS burst k, then for the corresponding RACH opportunity, the repeater will receive RACH on Rx beam n and transmit to the gNB on Tx beam m (relay the RACH).

[0127] Example Embodiments

[0128] Embodiment 1: An apparatus for wireless communication by a first wireless device, comprising: a memory; a processor coupled to the memory, the memory and the processor being configured to: determine a first group of one or more beams for receiving a synchronization signal block (SSB) from a base station (BS); determine a second group of one or more beams for transmitting the SSB received via the first group of beams; and use the first group of one or more beams and the second group of one or more beams to relay the SSB from the BS to at least one second wireless device.

[0129] Embodiment 2: The apparatus of embodiment 1, wherein the SSB is received in a burst; and the first group of one or more beams and the second group of one or more beams are used across bursts.

[0130] Embodiment 3: The apparatus of any one of embodiments 1-2, wherein the memory and the processor are further configured to: perform a random access procedure with the BS; and receive an indication of an SSB designated for relaying by the first wireless device.

[0131] Embodiment 4: The apparatus of any one of embodiments 1-3, wherein at least one beam in the second set of one or more beams is used to relay an SSB received from the BS using a different beam in the first set of one or more beams.

[0132] Embodiment 5: The apparatus of any one of embodiments 1-4, wherein the second set of one or more beams comprises a single wide beam.

[0133] Embodiment 6: An apparatus as in Embodiment 5, wherein the memory and the processor are further configured to: receive a random access channel (RACH) transmission from the at least one wireless device; and relay a random access response (RAR) to the at least one second wireless device using multiple beams within a second group of one or more beams that are narrower than the single wide beam.

[0134] Embodiment 7: An apparatus as in any one of embodiments 1-6, wherein the first group of one or more beams includes a same beam for receiving SSB from the BS.

[0135] Embodiment 8: An apparatus as in Embodiment 7, wherein the second set of one or more beams includes multiple beams for relaying SSBs received using the same beam.

[0136] Embodiment 9: The apparatus of embodiment 8, wherein the memory and the processor are further configured to: change the beam in the second group of one or more beams for different RACH association periods.

[0137] Embodiment 10: The apparatus of any one of embodiments 1-9, wherein the second set of one or more beams includes at least one beam that is wider relative to at least one narrower beam in the second set of one or more beams.

[0138] Embodiment 11: An apparatus as in Embodiment 10, wherein the memory and the processor are further configured to: determine which beams in the first group of one or more beams are to use a wider beam to relay SSB; and determine which beams in the first group of one or more beams are to use the at least one narrower beam to relay SSB.

[0139] Embodiment 12: The apparatus of embodiment 10 further comprises: changing the beam in the second group of one or more beams for different RACH associated time periods.

[0140] Embodiment 13: An apparatus as in any one of embodiments 1-12, wherein the memory and the processor are further configured to: participate in a RACH procedure with the at least one second wireless device; and maintain correspondence between beams in the first group of one or more beams and the second group of one or more beams for relaying SSBs when participating in the RACH procedure.

[0141] Embodiment 14: An apparatus as in Embodiment 13, wherein maintaining the correspondence comprises: receiving one or more messages from the at least one second wireless device using a same beam from the second group of one or more beams that was used to transmit the SSB to the at least one second wireless device during the RACH procedure; and transmitting one or more messages to the BS using a same beam from the first group of one or more beams that was used to receive the SSB from the BS during the RACH procedure.

[0142] Embodiment 15: An apparatus for wireless communication by a base station (BS), comprising: a memory; a processor coupled to the memory, the memory and the processor being configured to: determine a first group of one or more beams for sending a synchronization signal block (SSB) to a first wireless device to be relayed by the first wireless device to a second wireless device via a second group of one or more beams; and use the first group of one or more beams to transmit the SSB to the first wireless device.

[0143] Embodiment 16: An apparatus as in Embodiment 15, wherein the SSBs are transmitted in bursts; and the BS uses the same first set of one or more beams across the bursts.

[0144] Embodiment 17: The apparatus of any one of embodiments 15-16, wherein the memory and the processor are further configured to: perform a random access procedure with the first wireless device; and provide an indication of an SSB designated for relaying by the first wireless device.

[0145] Embodiment 18: An apparatus as in any one of embodiments 15-17, wherein at least one beam in the second set of one or more beams is used to relay an SSB received from the BS using a different beam in the first set of one or more beams.

[0146] Embodiment 19: An apparatus as in Embodiment 18, wherein the second set of one or more beams comprises a single wide beam.

[0147] Embodiment 20: An apparatus as in any one of embodiments 15-19, wherein the first set of one or more beams includes a same beam for transmitting SSB to the first wireless device.

[0148] Embodiment 21: An apparatus as in Embodiment 20, wherein the first set of one or more beams also includes another identical beam for transmitting an SSB to another first wireless device for relaying by the other first wireless device.

[0149] Embodiment 22: An apparatus as in Embodiment 21, wherein the BS uses at least one of time division multiplexing (TDM) or space division multiplexing (SDM) to transmit the SSB to the first wireless device and the another first wireless device.

[0150] Embodiment 23: The apparatus of any one of embodiments 15-22, wherein the second set of one or more beams includes at least one beam that is wider relative to at least one narrower beam in the second set of one or more beams.

[0151] Embodiment 24: The apparatus of any one of embodiments 15-23, wherein the memory and the processor are further configured to: participate in a random access channel (RACH) procedure with the second wireless device via an exchange of messages relayed by the first wireless device.

[0152] Embodiment 25: A method for wireless communication by a first wireless device, comprising: determining a first group of one or more beams for receiving a synchronization signal block (SSB) from a base station (BS); determining a second group of one or more beams for transmitting the SSB received via the first group of beams; and using the first group of one or more beams and the second group of one or more beams to relay the SSB from the BS to at least one second wireless device.

[0153] Embodiment 26: A method as in Embodiment 25, wherein the SSBs are received in bursts; and the same first set of one or more beams and second set of one or more beams are used across the bursts.

[0154] Embodiment 27: The method of any one of embodiments 25-26 further comprises: performing a random access procedure with the BS; and receiving an indication of an SSB designated for relaying by the first wireless device.

[0155] Embodiment 28: A method as in any one of embodiments 25-27, wherein at least one beam in the second set of one or more beams is used to relay an SSB received from the BS using a different beam in the first set of one or more beams.

[0156] Embodiment 29: A method for wireless communication by a base station (BS), comprising: determining a first group of one or more beams for sending a synchronization signal block (SSB) to at least a first wireless device for relaying by the first wireless device to a second wireless device via a second group of one or more beams; and using the first group of one or more beams to transmit the SSB to the first wireless device.

[0157] Embodiment 30: A method as in Embodiment 29, wherein the SSBs are transmitted in bursts; and the BS uses the same first set of one or more beams across the bursts.

[0158] Additional considerations

[0159] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be easily understood by those skilled in the art, and the universal principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but should be granted the full scope consistent with the claims in language, wherein the singular reference to the elements is not intended to mean "there is and only one", but "one or more", unless otherwise stated. Unless otherwise stated, the term "some / some" refers to one or more. The elements of the various aspects described throughout this disclosure are all structural and functional equivalents currently or hereafter known to ordinary technicians in the field, and are explicitly incorporated herein by reference, and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be donated to the public, regardless of whether such disclosure is explicitly recorded in the claims. Any element of the claim should not be interpreted under the provisions of 35 U.S.C. §112, paragraph 6, unless the element is explicitly stated using the wording "device for..." or in the case of a method claim, the element is stated using the wording "step for...".

[0160] The various operations of the methods described above may be performed by any suitable device capable of performing the corresponding functions. These devices may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. In general, where there are operations illustrated in the accompanying drawings, these operations may have corresponding paired device plus function components.

[0161] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0162] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as combinations including multiples of one or more members (aa, bb, and / or cc).

[0163] The various illustrative logical blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0164] The steps of the method or algorithm described in conjunction with the present disclosure may be implemented directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in any form of storage medium known in the art. Some examples of usable storage media include random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, and the like. The software module may include a single instruction, or many instructions, and may be distributed over several different code segments, distributed between different programs, and distributed across multiple storage media. A storage medium may be coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor.

[0165] The methods disclosed herein include one or more steps or actions for achieving the described methods. These method steps and / or actions may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be changed without departing from the scope of the claims.

[0166] The means for receiving or the means for obtaining may include Figure 3 10, or a receiver (such as a receive processor 338) or antenna(s) 334 of the AP 110, or a receive processor 358 or antenna(s) 352 of the UE 120. The means for transmitting or the means for outputting may include Figure 3 10, or the transmitter (such as transmit processor 320) or antenna(s) 334 of AP 110, or the transmit processor 364 or antenna(s) 352 of UE 120 as illustrated in FIG. Means for associating, means for determining, means for monitoring, means for deciding, means for providing, means for detecting, means for performing, and / or means for setting may include a processing system, which may include one or more processors, such as Figure 3 1. The receive processor 338 / 358, transmit processor 320 / 364, TX MIMO processor 330 / 366, or controller 340 / 380 of the AP 110 and UE 120 illustrated in FIG.

[0167] In some cases, a device may not actually transmit a frame, but may have an interface (means for outputting) for outputting a frame for transmission. For example, a processor may output a frame to a radio frequency (RF) front end via a bus interface for transmission. Similarly, a device may not actually receive a frame, but may have an interface (means for obtaining) for obtaining a frame received from another device. For example, a processor may obtain (or receive) a frame from an RF front end via a bus interface for reception.

[0168] The functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art and will not be described further.

[0169] The processor may be responsible for managing the bus and general processing, including executing software stored on a machine-readable medium. The processor may be implemented with one or more general and / or special processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuit systems that can execute software. Software should be broadly interpreted as meaning instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or other. As an example, a machine-readable medium may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. The machine-readable medium may be implemented in a computer program product. The computer program product may include packaging materials.

[0170] In a hardware implementation, the machine-readable medium may be a part of a processing system that is separate from the processor. However, as will be readily appreciated by those skilled in the art, the machine-readable medium or any part thereof may be external to the processing system. As an example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer product separated from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any part thereof may be integrated into the processor, such as a cache and / or a general register file may be the case.

[0171] The processing system can be configured as a general processing system having one or more microprocessors providing processor functionality and external memory providing at least a portion of the machine-readable medium, all linked together with other supporting circuitry via an external bus architecture. Alternatively, the processing system can be implemented with an ASIC (Application Specific Integrated Circuit) with a processor, bus interface, user interface (in the case of an access terminal), supporting circuitry, and at least a portion of the machine-readable medium integrated in a single chip, or with one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gating logic, discrete hardware components, or any other suitable circuitry, or any combination of circuits capable of performing the various functionalities described throughout this disclosure. Depending on the specific application and the overall design constraints imposed on the overall system, those skilled in the art will recognize how to best implement the functionality described with respect to the processing system.

[0172] The machine-readable medium may include several software modules. These software modules include instructions that cause the processing system to perform various functions when executed by the processor. These software modules may include a transmission module and a reception module. Each software module may reside in a single storage device or be distributed across multiple storage devices. As an example, when a triggering event occurs, the software module may be loaded into the RAM from the hard drive. During the execution of the software module, the processor may load some instructions into the cache to increase the access speed. One or more cache lines may then be loaded into the general register file for execution by the processor. When the functionality of the software module is described below, it will be understood that such functionality is implemented by the processor when the processor executes the instructions from the software module.

[0173] If implemented in software, each function can be stored on a computer-readable medium or transmitted as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, and these media include any media that facilitate the transfer of a computer program from one place to another. Storage media can be any available media that can be accessed by a computer. As an example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other media that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer. Similarly, any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared (IR), radio, and microwave), the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) is included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Disks, where disks often reproduce data magnetically, and discs reproduce data optically with lasers. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0174] Thus, some aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having stored (and / or encoded) thereon instructions that can be executed by one or more processors to perform the operations described herein. For some aspects, the computer program product may include packaging materials.

[0175] In addition, it should be appreciated that the modules and / or other appropriate devices for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or access point where applicable. For example, such a device can be coupled to a server to facilitate the transfer of the device for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) so that once the storage device is coupled to or provided to a user terminal and / or access point, the device can obtain the various methods. In addition, any other suitable technology suitable for providing the methods and techniques described herein to the device can be utilized.

[0176] It will be understood that the claims are not limited to the precise configuration and components illustrated above. Various changes, substitutions and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. An apparatus for wireless communication by a first wireless device, comprising: Memory; as well as a processor coupled to the memory, the memory and the processor being configured to: determining a first set of one or more beams for receiving a synchronization signal block (SSB) from a base station (BS); determining a second set of one or more beams for transmitting SSBs received via the first set of one or more beams; as well as The SSB is relayed from the BS to at least one second wireless device using the first group of one or more beams and the second group of one or more beams, wherein at least one beam of the second group of one or more beams is used to relay the SSB received from the BS using a different beam of the first group of one or more beams.

2. The device according to claim 1, wherein: The SSBs are received in bursts; and the first set of one or more beams and the second set of one or more beams are used across bursts.

3. The device according to claim 1, wherein: The memory and the processor are further configured to: performing a random access procedure with the BS; and An indication of an SSB designated for the first wireless device to perform the relaying is received.

4. The device according to claim 1, wherein: The second set of one or more beams includes a single wide beam.

5. The device according to claim 4, wherein: The memory and the processor are further configured to: receiving a random access channel (RACH) transmission from the at least one second wireless device; and A random access response (RAR) is relayed to the at least one second wireless device using a plurality of beams within the second set of one or more beams that are narrower than the single wide beam.

6. The device according to claim 1, wherein: The first set of one or more beams includes a same beam used to receive SSB from the BS.

7. The device according to claim 6, wherein: The second set of one or more beams includes a plurality of beams for relaying SSBs received using the same beam.

8. The device according to claim 7, wherein: The memory and the processor are further configured to: The beams in the second set of one or more beams are changed for different RACH associated periods.

9. The device of claim 1, wherein: The second set of one or more beams includes at least one beam that is wider relative to at least one narrower beam in the second set of one or more beams.

10. The device of claim 9, wherein: The memory and the processor are further configured to: determining which beams of the first set of one or more beams to use a wider beam to relay SSB; and A decision is made as to which beams of the first set of one or more beams are to be used to relay SSB using the at least one narrower beam.

11. The device of claim 9, wherein: The memory and the processor are further configured to: The beams in the second set of one or more beams are changed for different RACH associated periods.

12. The device of claim 1, wherein: The memory and the processor are further configured to: participating in a RACH procedure with the at least one second wireless device; as well as Maintaining a correspondence between beams used to relay SSBs in the first set of one or more beams and the second set of one or more beams when participating in the RACH procedure.

13. The device of claim 12, wherein: Maintaining the correspondence includes: receiving one or more messages from the at least one second wireless device during the RACH procedure using a same beam of the second set of one or more beams that was used to transmit the SSB to the at least one second wireless device; and One or more messages are transmitted to the BS during the RACH procedure using a same beam from the first set of one or more beams that was used to receive SSBs from the BS.

14. An apparatus for wireless communication by a base station (BS), comprising: Memory; as well as a processor coupled to the memory, the memory and the processor being configured to: determining a first set of one or more beams for transmitting a synchronization signal block (SSB) to a first wireless device for relaying by the first wireless device to a second wireless device via a second set of one or more beams, wherein at least one beam of the second set of one or more beams is used to relay an SSB received from the BS using a different beam of the first set of one or more beams; as well as The SSB is transmitted to the first wireless device using the first set of one or more beams.

15. The device of claim 14, wherein: The SSBs are transmitted in bursts; and the BS uses the same first set of one or more beams across the bursts.

16. The device of claim 14, wherein: The memory and the processor are further configured to: performing a random access procedure with the first wireless device; and An indication of an SSB designated for relaying by the first wireless device is provided.

17. The device of claim 14, wherein: The second set of one or more beams includes a single wide beam.

18. The device of claim 14, wherein: The first set of one or more beams includes a same beam used to transmit SSB to the first wireless device.

19. The device of claim 18, wherein: The first set of one or more beams also includes another identical beam for transmitting the SSB to another first wireless device for relaying by the another first wireless device.

20. The device of claim 19, wherein: The BS transmits the SSB to the first wireless device and the another first wireless device using at least one of time division multiplexing (TDM) or space division multiplexing (SDM).

21. The apparatus of claim 14, wherein: The second set of one or more beams includes at least one beam that is wider relative to at least one narrower beam in the second set of one or more beams.

22. The apparatus of claim 14, wherein: The memory and the processor are further configured to: engaging in a random access channel (RACH) procedure with the second wireless device via an exchange of messages relayed by the first wireless device.

23. A method for wireless communication by a first wireless device, comprising: determining a first set of one or more beams for receiving a synchronization signal block (SSB) from a base station (BS); determining a second set of one or more beams for transmitting SSBs received via the first set of one or more beams; as well as The SSB is relayed from the BS to at least one second wireless device using the first group of one or more beams and the second group of one or more beams, wherein at least one beam of the second group of one or more beams is used to relay the SSB received from the BS using a different beam of the first group of one or more beams.

24. The method of claim 23, wherein: The SSBs are received in bursts; and the same first set of one or more beams and second set of one or more beams are used across the bursts.

25. The method of claim 23, further comprising: performing a random access procedure with the BS; as well as An indication of an SSB designated for the first wireless device to perform the relaying is received.

26. The method of claim 23, further comprising: participating in a random access channel (RACH) procedure with the second wireless device; as well as maintaining a correspondence between beams in the first set of one or more beams and beams in the second set of one or more beams for relaying SSBs when participating in the RACH procedure, wherein maintaining the correspondence comprises: receiving one or more messages from the at least one second wireless device during the RACH procedure using a same beam of the second set of one or more beams that was used to transmit the SSB to the at least one second wireless device; as well as One or more messages are transmitted to the BS during the RACH procedure using a same beam from the first set of one or more beams that was used to receive SSBs from the BS.

27. A method for wireless communication by a base station (BS), comprising: determining a first set of one or more beams for transmitting a synchronization signal block (SSB) to at least a first wireless device for relaying by the first wireless device to a second wireless device via a second set of one or more beams, wherein at least one beam of the second set of one or more beams is used to relay an SSB received from the BS using a different beam of the first set of one or more beams; as well as The SSB is transmitted to the first wireless device using the first set of one or more beams.

28. The method of claim 27, wherein: The SSBs are transmitted in bursts; and the BS uses the same first set of one or more beams across the bursts.

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