System, method, and non-transitory processor-readable medium for transmission during random access procedures

Abstract

A system, method, non-transitory processor-readable medium, and apparatus for performing a random access channel (RACH) procedure involving a first node (e.g., an UL TRP) and a second node (e.g., a BS) by a wireless communication device (e.g., a UE), wherein the wireless communication device receives downlink data from the second node and communicates with the second node via the first node by the wireless communication device.

Description

[Technical Field]

[0001] The present disclosure relates generally to wireless communications, and more particularly to a system, method, and non-transitory processor-readable medium for information transmission during a random access procedure. [Background technology]

[0002] background Network deployment formats continue to change and evolve based on traditional network deployment. A cell may include multiple transmit / receive points (TRPs) in the same or different geographic locations. Some TRPs may support both downlink (DL) transmission and uplink (UL) reception. Some TRPs may support only some transmission types, such as UL reception (e.g., UL-only TRPs, UL TRPs, UL-only cells, etc.). In this network deployment mode, UL-only TRPs can be used to extend uplink coverage and capacity. Another network deployment involves a forwarding-based network, in which special relay nodes (e.g., relays, integrated access backhauls (IABs), network-controlled repeaters (RNs), etc.) are deployed to amplify and forward received signals between base stations (BSs) and user equipment (UEs), thereby extending the BS's UL and DL coverage areas. However, these network deployments face challenges related to physical random access channel (PRACH) transmission when the UL and DL transmitting and receiving nodes are different, such as transmission resource configuration, transmission timing, transmission power determination, and how relay nodes forward initial access-related signaling channels (e.g., synchronization signal / physical broadcast channel (SS / PBCH) block (SSB), PRACH, etc.). Summary of the Invention [Means for solving the problem]

[0003] overview In some configurations, a system, method, apparatus, and non-transitory computer-readable medium for performing a random access channel (RACH) procedure involving a first node (e.g., a UL TRP, etc.) and a second node (e.g., a BS, etc.) by a wireless communication device (e.g., a UE, etc.), wherein the wireless communication device receives downlink data from the second node and communicates with the second node via the first node by the wireless communication device.

[0004] These and other aspects and their implementations are described in more detail in the drawings, specification, and claims. [Brief explanation of the drawings]

[0005] Various exemplary configurations of the present solution are described in detail below with reference to the following figures or drawings. The drawings are provided for illustrative purposes only and merely depict exemplary configurations of the present solution to facilitate the reader's understanding of the present solution. Therefore, the drawings should not be considered as limiting the breadth, scope, or applicability of the present solution. It should be noted that for clarity and ease of illustration, the drawings are not necessarily drawn to scale.

[0006] [Figure 1] FIG. 1 illustrates an example of a cellular communication network, according to some configurations.

[0007] [Figure 2] 1 illustrates block diagrams of an example UL device, an example UE device, and an example BS device, according to some configurations.

[0008] [Figure 3] 1 illustrates an example of a scheme that may be implemented to support initial access.

[0009] [Figure 4]1 is a table illustrating an example of a mapping relationship between a PRACH configuration index, a preamble format, a system frame number (SFN), a subframe number, a start symbol, a number of PRACH slots in a subframe, a number of time-domain PRACH opportunities in a PRACH slot, and a PRACH duration for various configurations.

[0010] [Figure 5] Preamble subcarrier spacing (SCS) and [ka] 10 is a table illustrating an example of a mapping relationship between symbols.

[0011] [Figure 6] FIG. 1 illustrates an example of a wireless communication system including a UL-only TRP, according to some configurations.

[0012] [Figure 7] FIG. 1 illustrates an example of a network deployment including a transport-based network, according to some configurations.

[0013] [Figure 8A] FIG. 10 is a flowchart illustrating an example method for performing a RACH procedure involving multiple nodes, according to various configurations. [Figure 8B] FIG. 10 is a flowchart illustrating an example method for performing a RACH procedure involving multiple nodes, according to various configurations.

[0014] [Figure 9] A diagram illustrating an example of combining transmit (Tx) and receive (Rx) to identify the best or acceptable Tx / Rx beam pair according to some configurations.

[0015] [Figure 10]FIG. 1 illustrates an example of a cellular communication network including transmission delays (T1, T2, T3) according to some configurations.

[0016] [Figure 11] FIG. 1 illustrates an example timeline of receive and transmit timing according to some configurations.

[0017] [Figure 12] 1 is a table illustrating an example of a mapping relationship between synchronization signal reference signal received power (SS-RSRP) measurements and power offsets (P_offset) according to various configurations.

[0018] [Figure 13] 10 is a table illustrating another example of a mapping relationship between SS-RSRP and P_offset according to various configurations.

[0019] [Figure 14] 1A-1C illustrate an example of SSB transmission according to various configurations.

[0020] [Figure 15] 10 is a table illustrating an example of a mapping relationship between refined SSB index, SFN, and half frame according to various configurations.

[0021] [Figure 16] 10 is a table illustrating another example of a mapping relationship between refined SSB indexes and SFNs according to various configurations.

[0022] [Figure 17] 10A-10C illustrate an example of a mapping relationship between refined SSBs and ROs according to various configurations.

[0023] [Figure 18] 10A-10C illustrate an example of refined SSB transmission according to various configurations.

[0024] [Figure 19] FIG. 1 illustrates an example method for radio resource control (RRC) setup, according to various configurations. DETAILED DESCRIPTION OF THE INVENTION

[0025] Detailed Description To enable those skilled in the art to make and use the present solution, various exemplary configurations of the present solution are described below with reference to the accompanying drawings. As will be apparent to those skilled in the art, after reading this disclosure, various changes or modifications can be made to the examples described herein without departing from the scope of the present solution. Thus, the present solution is not limited to the example configurations and applications described and illustrated herein. Furthermore, any specific order or hierarchy of steps in the methods disclosed herein is merely an example approach. Based on design preferences, the specific order or hierarchy of steps in a disclosed method or process can be rearranged while remaining within the scope of the present solution. Thus, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or operations in a sample order, and that the present solution is not limited to the specific order or hierarchy presented, unless otherwise specified.

[0026] UL-only TRP and forwarding-based network deployments have problems with initial access procedures because they have different UL and DL transmitting and receiving nodes. The configurations disclosed herein relate to improving the UL-only TRP initial access procedures and forwarding-based network deployments. The configurations disclosed herein relate to information transmission during a random access procedure.

[0027] FIG. 1 illustrates an example of a wireless communication system 100 according to configurations of the present disclosure. In the following description, the wireless communication system 100 may be any wireless network, such as a cellular network or a narrowband network. The system 100 includes a first node (FN) 102 and a UE 104 that can communicate with each other via a first communication link 110 (e.g., a wireless communication channel). In some configurations, the first node 102 includes an uplink-only node (e.g., a UL-only TRP, etc.). In some configurations, the first node 102 includes an uplink and downlink TRP (e.g., a TRP, a UL and DL TRP, etc.). The system 100 further includes a second node (SN) 106 that can communicate with the UE 104 via a second communication link 120 and can communicate with the first node 102 via a third communication link 130. In some configurations, the second node 106 includes a base station. The system 100 further includes a cluster of cells (e.g., at least 160, 162, 164, 166, 168, 170, and 172) that overlap with the geographic area 101. In FIG. 1 , the first node 102, the UE 104, and the second node 106 are shown disposed within respective geographic boundaries of the cell 160. Each of the other cells 162, 164, 166, 168, 170, and 172 may include at least one BS operating in its assigned bandwidth to provide adequate radio coverage to its intended user. For example, the second node 106 may operate in an assigned channel transmission bandwidth to provide adequate coverage to the UE 104. In some configurations, the first node 102 is a TRP that supports a subset of transmission types, e.g., UL reception only (e.g., UL-only TRP, UL TRP, UL-only cell, etc.).

[0028] In some embodiments, the second node 106 communicates with the UE 104 via a downlink radio frame 140, the UE 104 communicates with the first node 102 via a first uplink radio frame 146, and the first node 102 communicates with the second node 106 via a second uplink radio frame 152. Each radio frame 140, 146, 152 may be further divided into subframes (or slots) 142, 148, 154, which may include data symbols 144, 150, 156. In this disclosure, the first node 102, the UE 104, and the second node 106 are generally described herein as non-limiting examples of communication nodes capable of implementing the methods disclosed herein. Such communication nodes may be capable of wireless and / or wired communication in accordance with various configurations of the present solution.

[0029] 2 illustrates a block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals, according to some configurations. System 200 may include components and elements configured to support known or conventional operational features that need not be described in detail herein. In some configurations, as previously mentioned, system 200 may be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment, such as wireless communication system 100 of FIG. 1.

[0030] The system 200 generally includes a first node (FN) 202, a UE 204, and a second node (SN) 206. In some configurations, the first node 202 includes an uplink-only node (e.g., a UL-only TRP). In some configurations, the first node 202 includes an uplink and downlink TRP (e.g., a TRP, a UL and DL TRP). The first node 202 includes an FN transceiver module 210, an FN antenna 212, an FN processor module 214, an FN memory module 216, and an FN network communication module 218, each of which is coupled and interconnected as needed via an FN data communication bus 220. The UE 204 includes a UE transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each of which is coupled and interconnected as needed via a UE data communication bus 240. The UE 204 communicates with the first node 202 via a first communication channel 250 (e.g., a first wireless transmission link, a first wireless data transmission link, etc.), which may be any wireless channel or other medium suitable for the transmission of data as described herein. In some configurations, the second node 106 comprises a base station. The second node 206 includes an SN transceiver module 260, an SN antenna 262, an SN processor module 264, an SN memory module 266, and an SN network communication module 268, each coupled and interconnected as needed via an SN data communication bus 270. The second node 206 communicates with the UE 204 via a second communication channel 280 (e.g., a second wireless transmission link, a second wireless data transmission link, etc.), which may be any wireless channel or other medium suitable for the transmission of data as described herein. The first node 202 communicates with the second node 206 via a third communication channel 290 (e.g., a third wireless transmission link, a third wireless data transmission link, etc.), which may be any wireless channel or other medium suitable for transmitting data as described herein.

[0031] System 200 may further include any number of modules other than those shown in FIG. 2 . The various example blocks, modules, circuits, and processing logic described in connection with the configurations disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this compatibility and adaptability of hardware, firmware, and software, the various example components, blocks, modules, circuits, and steps have been described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software may depend on the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a manner suitable for each particular application, but such implementation decisions should not be construed as limiting the scope of the present disclosure.

[0032] According to some configurations, the FN transceiver module 210 may be referred to herein as a first uplink transceiver including a radio frequency (RF) transmitter and an RF receiver, each with circuitry coupled to the FN antenna 212. Alternatively, a duplexing switch (not shown) may couple the uplink transmitter or receiver to the uplink antenna in a time-duplexed manner. Similarly, the UE transceiver module 230 may be referred to herein as a second uplink transceiver including an RF transmitter and an RF receiver, each with circuitry coupled to the UE antenna 232. Alternatively, a duplexing switch (not shown) may couple the uplink transmitter or receiver to the uplink antenna in a time-duplexed manner. Similarly, according to some configurations, the SN transceiver module 260 may be referred to herein as a downlink transceiver including an RF transmitter and an RF receiver, each with circuitry coupled to the SN antenna 262. Alternatively, a downlink duplexing switch may couple the downlink transmitter or receiver to the downlink antenna in a time-duplexed manner.

[0033] In some embodiments, the operation of the two transceiver modules 230 and 260 can be coordinated in time such that the downlink transmitter is coupled to the SN antenna 262 at the same time that the second uplink transceiver is coupled to the UE antenna 232 for receiving transmissions over the second wireless transmission link 280. In some configurations, there is strict time synchronization with a minimum guard time between changes in duplex direction. In some embodiments, the second uplink transceiver is coupled to the UE antenna 232 for receiving transmissions over the second wireless transmission link 280, the first uplink transceiver is coupled to the FN antenna 212 for receiving transmissions over the first wireless transmission link 250, and simultaneously the downlink transmitter is coupled to the SN antenna 262 for transmitting transmissions over the second wireless transmission link 280.

[0034] The UE transceiver module 230 and the SN transceiver module 260 are configured to communicate over the second wireless data communication link 280 and cooperate with a suitably configured RF antenna configuration 232 / 262 capable of supporting a particular wireless communication protocol and modulation scheme. The UE transceiver module 230 and the FN transceiver module 210 are configured to communicate over the first wireless data communication link 250 and cooperate with a suitably configured RF antenna configuration 232 / 212 capable of supporting a particular wireless communication protocol and modulation scheme. The UE transceiver module 230 and the SN transceiver module 260 are configured to communicate over the third wireless data communication link 290 and cooperate with a suitably configured RF antenna configuration 212 / 262 capable of supporting a particular wireless communication protocol and modulation scheme. In some exemplary configurations, the FN transceiver module 210, the UE transceiver module 230, and the SN transceiver module 260 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G standards. However, it will be understood that the present disclosure is not necessarily limited in application to any particular standard and associated protocol. Rather, FN transceiver module 210, UE transceiver module 230, and SN transceiver module 260 may be configured to support alternative or additional wireless data communication protocols, including future standards or variants thereof.

[0035] According to various configurations, the first node 202 may be, for example, a UL-only TRP. In some configurations, the UE 204 may be embodied in various types of user devices, such as a mobile phone, a smartphone, a personal digital assistant (PDA), a tablet, a laptop computer, a wearable computing device, etc. In some configurations, the second node 206 may be, for example, a gNB, an evolved Node B (eNB), a serving eNB, a target eNB, a femto station, or a pico station. The processor modules 214, 236, and 264 may be implemented or realized using a general-purpose processor, an associative memory, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. As such, the processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, etc. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

[0036] Furthermore, the steps of a method or algorithm described in connection with the configurations disclosed herein may be embodied directly in hardware, in firmware, in software modules executed by processor modules 214, 236, and 264, respectively, or any practical combination thereof. Memory modules 216, 234, and 266 may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules 216, 234, and 266 may be coupled to processor modules 214, 236, and 264, respectively, such that processor modules 214, 236, and 264 can read information from and write information to memory modules 216, 234, and 266, respectively. Memory modules 216, 234, and 266 may also be incorporated into each processor module 214, 236, and 264, respectively. In some configurations, memory modules 216, 234, and 266 may each include cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 214, 236, and 264, respectively. Memory modules 216, 234, and 266 may also each include non-volatile memory for storing instructions to be executed by processor modules 214, 236, and 264, respectively.

[0037] The FN network communication module 218 generally corresponds to hardware, software, firmware, processing logic, and / or other components of the first node 202 that enable bidirectional communication between the FN transceiver module 210 and other network components and communication nodes configured to communicate with the first node 202. For example, the FN network communication module 218 may be configured to support Internet or WiMAX traffic. In a typical deployment, without limitation, the FN network communication module 218 provides an 802.3 Ethernet interface to enable the FN transceiver module 210 to communicate with conventional Ethernet-based computer networks. As such, the FN network communication module 218 may include a physical interface for connecting to a computer network (e.g., a mobile switching center (MSC)). As used herein with respect to a specified operation or function, the terms “configured for,” “configured to,” and conjugations thereof refer to devices, components, circuits, structures, machines, signals, etc. that are physically structured, programmed, formatted, and / or arranged to perform the specified operation or function.

[0038] Similarly, the SN network communication module 268 generally corresponds to the hardware, software, firmware, processing logic, and / or other components of the second node 206 that enable bidirectional communication between the SN transceiver module 260 and other network components and communication nodes configured to communicate with the second node 206. For example, the SN network communication module 268 may be configured to support Internet or WiMAX traffic. In a typical deployment, without limitation, the SN network communication module 268 provides an 802.3 Ethernet interface to enable the SN transceiver module 260 to communicate with conventional Ethernet-based computer networks. In this manner, the SN network communication module 268 may include a physical interface for connecting to a computer network.

[0039] In some examples, FIG. 3 illustrates an example of a scheme 300 implemented to support initial access (e.g., a PRACH procedure) under frequency range FR1 (e.g., a sub-6 GHz band) and frequency range FR2 (e.g., above the 6 GHz band). In FIG. 3, base station communication 301 (e.g., beamforming) of a base station (e.g., a second node 106 / 206) may be shown on the top rail, and UE communication 302 (e.g., beamforming) of a UE (e.g., a UE 104, 204) may be shown on the bottom rail. PRACH transmission may be transmitted, for example, via Msg1 310. Scheme 300 may further include different PRACH formats, PRACH resource configurations, relationships between synchronization signal / physical broadcast channel (SS / PBCH) blocks (SSBs) and PRACH opportunities (ROs), mechanisms for PRACH retransmission, mechanisms for PRACH power control, etc.

[0040] The hatched beams in FIG. 3 are beams used to transmit or receive data. As shown in FIG. 3, the UE transmits a preamble over the RO according to the PRACH transmission and the selected SSB configuration. When transmitting the preamble over the RO, a fixed mapping between the UE's receive (Rx) beam and the UE's transmit (Tx) beam can be used if the UE's transmit-receive (Tx-Rx) correspondence can be guaranteed. A specific Tx beam can be determined according to its reception of the SSB. For example, the UE can attempt to use different Rx beams 303 to receive the SSB from the base station (e.g., at 305) and determine the best Rx beam 304. In some configurations, the best Rx beam 304 (e.g., the best downlink Rx beam) is the beam with the highest reference signal received power (RSRP) or an RSRP value higher than a predetermined threshold. According to the best Rx beam 304, the best Tx beam 306 (e.g., the best uplink Tx beam) is determined based on the beam correspondence. The RO used for the PRACH transmission is determined according to the relationship between the SSB and the RO. Based on this relationship, the base station can determine the SSB selected by the UE. The same beam 315 can be used to transmit subsequent downlink transmissions, including Msg2 320 (which may be referred to as a random access response (RAR)) and Msg4 340 (which may be a physical downlink shared channel (PDSCH) with a UE contention resolution identity). According to the RACH procedure, the RAR (e.g., Msg2 320) is communicated after the end of the PRACH transmission (e.g., Msg1 310). The UE can monitor the RAR physical downlink control channel (PDCCH) within the RAR window. The RAR window begins at least a predetermined number of time units (e.g., symbols) after the last symbol of the RO corresponding to the PRACH transmission, i.e., the first symbol of the earliest control resource set (CORESET) on which the UE is configured to receive the PDCCH for the Type 1-PDCCH common search space (CSS) set.

[0041] In some configurations, if the Tx-Rx correspondence at the UE side cannot be guaranteed, the UE may try different Tx beams to transmit the PRACH. According to the RACH procedure, the UE can find a suitable transmission beam through RACH retransmission / retry using a modified beam after a previous RACH transmission failure, which may be inefficient.

[0042] In some configurations, a first network deployment mode includes multiple transmission / reception points (TRPs), which may all be located in the same or different geographic locations. Some TRPs may support both downlink transmission and uplink reception. Other TRPs may support only some transmission types, such as uplink reception (e.g., UL-only TRPs, UL TRPs, UL-only cells, etc.). In the first network deployment mode, UL-only TRPs can be used to extend uplink coverage and capacity. In some configurations, a second network deployment mode includes a forwarding-based network, in which specialized relay nodes (e.g., relays, integrated access backhauls (IABs), network-controlled repeaters (RNs), etc.) are deployed to amplify and forward received signals between the BS and UEs, thereby extending the UL and DL coverage areas of the BS.

[0043] The first and second network deployment modes may face issues regarding PRACH transmission, such as when the UL and DL transmitting and receiving nodes are different (e.g., SSB is transmitted by the BS and PRACH is received by the UL, etc.), transmission resource configuration, transmission timing, transmission power determination, how the relay node forwards initial access-related signaling channels (e.g., PBCH Block SSB, PRACH, etc.), etc.

[0044] 4 is a table illustrating an example of a mapping relationship between a PRACH configuration index, a preamble format, an SFN, a number of subframes, a starting symbol, a number of PRACH slots in a subframe, a number of time-domain ROs in a PRACH slot, and a PRACH duration according to various configurations. In some configurations, the SFN at which a PRACH resource is located can be calculated using the formula nf mod x=y, where x corresponds to the periodicity (in terms of system frames or milliseconds) of the PRACH resource and y corresponds to the frame at which the PRACH resource is located for each periodicity. In some configurations, the table illustrated in FIG. 4 is a table for a random access configuration. The time-domain resources for RACH transmission are configured via a radio resource control (RRC) signaling PRACH configuration index. The PRACH configuration index maps to a line in the table illustrated in FIG. 4 to determine one or more of the preamble format, the number of frames, the number of subframes, the starting symbol, the number of PRACH slots in a subframe, the number of time-domain ROs in a PRACH slot, and the PRACH duration. 4 includes 256 rows (eg, lines). In some configurations, the value of the PRACH configuration index is between about 0 and about 255.

[0045] In some configurations, the frequency domain resources for PRACH transmission are configured via RRC signaling, where msg1-FrequencyStart provides the frequency starting RB within a carrier or bandwidth portion, and msg1-Frequency Division Multiplexing (FDM) provides how many RACH transmission resources are FDMed. For example, the frequency domain resources for RACH transmission may be configured via the following RRC signaling: [ka]

[0046] In some configurations, the RO may be determined based on a time and frequency domain resource configuration.

[0047] Figure 5 shows the preamble subcarrier spacing (SCS) and [ka] 1 is a table illustrating an example of a mapping relationship between symbols (e.g., the number of PRACH slots in a subframe) and [ka] The symbols may be determined based on the preamble SCS. For example, based on FIG. 5, a subframe containing a 1 millisecond (ms) duration of a 30 kHz SCS (including a PRACH slot with a duration equal to 0.5 ms) may have 2 [ka] In some configurations, the validity of the RO can be verified. For example, if the UE is provided (e.g., tdd-UL-DL-ConfigurationCommon), it can verify that (i) the RO is within a UL symbol, or (ii) (a) the RO does not precede an SS / PBCH block in a PRACH slot, and (b) the RO is at least 1 symbol after the last downlink symbol. [ka] symbols after the last SS / PBCH block symbol, and (c) the RO begins at least [ka] If the RO in the PRACH slot starts with a symbol, the RO in the PRACH slot can be verified as valid. In some configurations, the preamble format illustrated in FIG. [ka] For example, the B4 preamble format corresponds to 0 symbols. [ka] It may correspond to a symbol.

[0048] FIG. 6 illustrates an example wireless communication system 600 including a UL-only TRP according to some configurations. The wireless communication system 600 includes multiple TRPs 610. In some configurations, each TRP 610 is located at a different geographic location. In some configurations, one TRP (e.g., the second node 106 / 206) of the multiple TRPs 610 supports both downlink transmission and uplink reception, while the remaining four TRPs 610 (e.g., the first node 102 / 202, the UL-only TRP, the UL TRP, etc.) support a subset of transmission types, e.g., uplink reception. During the initial access procedure, the UE 104 / 204 detects an SSB transmitted by the second node 106 / 206 for DL ​​synchronization and system information acquisition. After detecting the SSB, the UE 104 / 204 initiates a RACH procedure for the SSB. As illustrated in FIG. 6, the downlink transmitting node (e.g., the second node 106 / 206) may be different from the uplink receiving node (e.g., the first node 102 / 202), and as a result, downlink measurements, such as determining beam information, timing information, power information, etc., may not be applicable for use as a reference for uplink transmission.

[0049] 7 is a diagram illustrating an example of a wireless communication system 700 including a forwarding-based network, according to some configurations. The wireless communication system 700 includes one or more relay nodes (RNs) 710 (e.g., relays, integrated access backhauls (IABs), network-controlled repeaters (NCRs), etc.) configured to amplify and forward received signals between a second node 106 / 206 and a UE 104 / 204, thereby extending the uplink and downlink coverage areas of the SBs 106 / 206. The wireless communication system 700 further includes one or more backhaul links 720 between the second node 106 / 206 and the RNs 710, and one or more access links 730 between the RNs 710 and the UEs 104 / 204. In some configurations, each of one or more backhaul links 720 is associated with a particular SSB (e.g., SSB0, SSB1, SSB2, etc.) such that the RN 710 receives a particular SSB (e.g., SSB0) on a corresponding backhaul link 720, and each of one or more access links 730 is associated with a particular refined SSB (e.g., refined SSB#0, refined SSB#1, refined SSB#2, etc.). This configuration provides a method herein for forwarding an SSB (e.g., a particular refined SSB) to a UE 104 / 204, forwarding subsequent uplink transmissions (e.g., PRACH) from the UE 104 / 204, and specifying actions when the forwarding node accepts initial access for a subordinate UE (e.g., UE 104 / 204).

[0050] In some configurations, the uplink coverage area of ​​the UE 104 / 204 may correspond to the first node 102 / 202 or the second node 106 / 206, such that the UE 104 / 204's uplink transmission may be transmitted directly to the second node 106 / 206 or forwarded to the second node 106 / 206 via the first node 102 / 202. Different uplink receiving nodes may affect the UE 104 / 204's subsequent initial access process (different initial access processes are referred to as different RACH modes of the UE 104 / 204). In some configurations, the UE 104 / 204 may select from at least two RACH modes, including a first RACH mode and a second RACH mode. The determination of the RACH mode by the UE 104 / 204 can also be considered as determining the transmission link for the PRACH transmission, e.g., the PRACH is transmitted to the first node 102 / 202 (corresponding to the first RACH mode) or the second node 106 / 206 (corresponding to the second RACH mode). In other words, the determination of the RACH mode by the UE 104 / 204 relates to how the UE 104 / 204 determines the receiving node for uplink transmission.

[0051] In some configurations, the UE 104 / 204 determines or selects the RACH mode by utilizing a particular mechanism before initiating the random access process or during the random access process. In some examples, the mechanism for selecting the RACH mode includes defining a measurement threshold (e.g., an RSRP threshold, etc.). For example, the UE 104 / 204 performs a measurement and compares the measurement result to the measurement threshold. In some configurations, the transmission includes at least one of a reference signal, data, etc. In some configurations, the measurement includes at least one of RSRP, SS-RSRP, received signal strength indication (RSSI), signal-to-noise-plus-interference ratio (SINR), channel quality indicator (CQI), etc. In some examples, the measurement includes an SS-RSRP measurement. In response to determining that the measurement result is below or equal to the measurement threshold, the UE 104 / 204 selects a first RACH mode (e.g., selects the first node 102 / 202 as an uplink receiving node (an uplink receiving node is not a node transmitting SSB)). In response to determining that the measurement result is above or equal to the measurement threshold, the UE 104 / 204 selects a second RACH mode (e.g., selects the second node 106 / 206 as an uplink receiving node (an uplink receiving node is a node transmitting SSB)).

[0052] In some examples, the mechanism for selecting the RACH mode includes defining a measurement threshold range (e.g., an RSRP value range including two RSRP values ​​(a minimum RSRP value and a maximum RSRP value)). For example, the UE 104 / 204 performs a measurement and compares the measurement result with the measurement threshold range. In response to determining that the measurement result is within the measurement threshold range, the UE 104 / 204 selects a first RACH mode (e.g., selects the first node 102 / 202 as the uplink receiving node). In response to determining that the measurement result is outside the measurement threshold range, the UE 104 / 204 selects a second RACH mode (e.g., selects the second node 106 / 206 as the uplink receiving node).

[0053] In some examples, the mechanism for selecting a RACH mode includes the UE 104 / 204 performing random access using a default RACH mode (e.g., one of the first RACH mode and the second RACH mode), and if the number of RACH failures reaches a certain threshold (e.g., the number of failed attempts), the UE 104 / 204 switches to a non-default RACH mode (e.g., the other of the first RACH mode and the second RACH mode) to continue the random access procedure. For example, selecting the first RACH mode or the second RACH mode includes selecting one of the first RACH mode or the second RACH mode in response to failing the RACH procedure with respect to the number of attempts using the other of the first RACH mode or the second RACH mode, where the number of attempts is equal to or greater than a threshold.

[0054] In some examples, the mechanism for selecting a RACH mode includes the UE 104 / 204 performing random access using a default RACH mode, and when the preamble transmission power reaches a maximum value but still fails, the UE 104 / 204 switches to a non-default RACH mode to continue the random access procedure. For example, selecting the first RACH mode or the second RACH mode includes selecting one of the first RACH mode or the second RACH mode in response to the power of preamble transmission in the other of the first RACH mode or the second RACH mode reaching a predetermined value but still failing. In some configurations, the predetermined value includes a maximum transmission power of preamble transmission configured by the second node. In some configurations, the power of preamble transmission is increased after each failed attempt.

[0055] The mechanism for selecting a RACH mode may be SSB-specific, such that whether RACH mode selection needs to be performed for different SSBs can be independently configured, and parameter values ​​in the RACH mode selection mechanism may differ for different SSBs. In some configurations, for each SSB, the second node 106 / 206 may configure whether multiple RACH modes exist when the SSB is selected for random access (e.g., whether RACH mode selection needs to be performed for this SSB). In some examples, if there is only one RACH mode for the SSB, only one RACH mode may be indicated. In some examples, if no RACH mode is indicated, a default RACH mode is applied. In some configurations, there are multiple RACH modes for the SSB, and the configuration information further includes parameter values ​​required for RACH mode selection for the SSB. As described above, different RACH modes are defined, and several rules for determining or selecting the RACH mode are also defined. The UE 104 / 204 can effectively select a RACH mode suitable for the random access procedure.

[0056] 8A and 8B are flow chart diagrams illustrating an example of a method 800 for performing a RACH procedure involving multiple nodes according to various configurations. The method may be performed by a first node 102 / 202, a UE 104 / 204, and a second node 106 / 206 according to various configurations.

[0057] 8A, at 810, the UE 104 / 204 performs a RACH procedure involving a first node (e.g., the first node 102 / 202) and a second node (e.g., the second node 106 / 206), and the UE 104 / 204 receives downlink data from the second node. At 812, the UE 104 / 204 communicates with the second node 106 / 206 via the first node 102 / 202. In some configurations, the UE 104 / 204 receives a DL transmission from the second node 106 / 206 and transmits a UL transmission via the first node 102 / 202. In some configurations, the UE 104 / 204 selects a first RACH mode or a second RACH mode. In some configurations, the first RACH mode or the second RACH mode is selected for an SSB, a respective beam, or a channel state information-reference signal (CSI-RS). In some examples, the UE 104 / 204 selects at least one of the SSB, the beam, or the CSI-RS and determines the RACH mode based on the selected at least one of the SSB, the beam, or the CSI-RS.

[0058] At 820, the UE 104 / 204 transmits a PRACH to the second node 106 / 206 in the second RACH mode. At 822, the second node 106 / 206 receives the PRACH from the UE 104 / 204. At 826, the UE 104 / 204 transmits a PRACH to the first node 102 / 202 in the first RACH mode. At 828, the first node 102 / 202 receives the PRACH from the UE 104 / 204.

[0059] In some configurations, as shown in FIG. 8B , at 818, the second node 106 / 206 sends a transmission to the UE 104 / 204. In some examples, the UE 104 / 204 selects the second RACH mode in response to determining that a measurement result of the transmission from the second node 106 / 206 is (i) greater than or equal to a threshold, or (ii) out of range. In some configurations, at least one of “greater than” or “less than” does not include equal. In some configurations, at least one of “greater than” or “less than” includes equal to (e.g., greater than or equal to, less than or equal to, etc.). In some configurations, at 824, the second node 106 / 206 sends a transmission to the UE 104 / 204. In some examples, the UE 104 / 204 selects the first RACH mode in response to determining that a measurement result of a transmission from the second node 106 / 206 is (i) less than or equal to a threshold value, or (ii) within a range.

[0060] In some configurations, the wireless communication device includes at least one processor and a memory, where the at least one processor is configured to read code from the memory to perform method 800. In some configurations, the computer program product is a computer-readable program medium having stored thereon code that, when executed by the at least one processor, causes the at least one processor to perform method 800.

[0061] In some configurations, the UE 104 / 204 selects a first transmission link for the RACH procedure or a second transmission link for the PRACH transmission, where the first transmission link is between the wireless communication device and a first node and the second transmission link is between the wireless communication device and a second node.

[0062] In some configurations, the UE 104 / 204 determines the DL cell by detecting an SSB. For example, the UE 104 / 204 selects an SSB whose SS-RSRP is higher than a predetermined threshold (the RSRP threshold configured by the second node 106 / 206), and the synchronization signals (including the primary synchronization signal (PSS) and the secondary synchronization signal (SSS)) in the SSB carry cell ID information. The UE 104 / 204 uses the beam for receiving the SSB as the receiving beam for subsequent downlink reception in the RACH procedure.

[0063] In some configurations, the UE 104 / 204 transmits a preamble (e.g., Msg. 1) in a group of ROs using different transmit beams. Because the UE 104 / 204's uplink and downlink are asymmetric (the downlink transmission is received from a second node (e.g., a second node 106 / 206, a gNB, etc.) and the uplink is transmitted to a first node (e.g., a first node 102 / 202, a UL-only TRP, etc.)), the beam to use for the uplink transmission cannot be determined based on the downlink reception. In some examples, the beam used for the uplink transmission is based on training the receive beam for the first node 102 / 202 and the transmit beam for the UE 104 / 204. For example, different Rx / Tx beam pairs can be tried for receiving and transmitting the PRACH to determine an optimal or acceptable Rx / Tx beam pair for a subsequent UL transmission (e.g., Msg. 3 PUSCH). In some examples, the UE 104 / 204 selects a receive / transmit (Rx / Tx) beam pair by trying multiple receive / transmit beam pairs, and the receive / transmit beam pair is used to send an uplink transmission from the UE 104 / 204 to the first node.

[0064] 9 is a diagram illustrating an example of combining transmit (Tx) and receive (Rx) beams to identify the best or acceptable Tx / Rx beam pair according to some configurations. As shown in FIG. 9, multiple ROs 910 (e.g., four ROs) are associated with the same SSB. In this example illustrated in FIG. 9, when a UE 104 / 204 selects an SSB to initiate a random access process, there are M (e.g., M=2) Tx beams on the UE side and N (e.g., N=2) Rx beams on the UL-only TRP side. When a UE 104 / 204 initiates initial access to a UL-only TRP, the UE 104 / 204 does not know which Tx beam will be used to enable the network side to effectively receive data, and the first node 102 / 202 does not know which Rx beam will be used to effectively receive data. In some configurations, within at least M*N (i.e., 4) ROs 910, the preamble is transmitted / received via different combinations of Tx and Rx beams to identify the best or acceptable Tx / Rx beam pair. For example, the UE 104 / 204 transmits the preamble to the network using a transmit beam of each of a plurality of receive / transmit beam pairs, each of the plurality of receive / transmit beam pairs including one (e.g., N) of a plurality of receive beams and one (e.g., M) of a plurality of transmit beams. The transmit beam is one of the plurality of transmit beams. The network receives the preamble using a receive beam of each of a plurality of receive / transmit beam pairs, the receive beam being one of the plurality of receive beams.

[0065] In some examples, Tx / Rx switching rules between different ROs can be predefined. For example, the UE 104 / 204 can transmit a preamble using a first Tx beam a predetermined number of times until all Tx beams have been traversed, switch the Tx beam to a second Tx beam, and transmit the preamble a predetermined number of times, etc. In some examples, for each predetermined number of preamble transmissions, the first node 102 / 202 can switch its Rx beam. In some configurations, the predetermined number is equal to or greater than the number of Rx beams of the first node 102 / 202. In some configurations, the ROs 910 used in preamble transmissions in one RACH attempt can be defined as an RO group. For example, a preamble is transmitted in a group of ROs using multiple receive / transmit beam pairs, with each RO in the group of ROs corresponding to one of the multiple receive / transmit beam pairs. In some configurations, the ROs 910 used to transmit a preamble on the same transmission beam within a single RACH attempt can be defined as an RO group, with M RO groups being used during a single RACH attempt. For example, the preamble is transmitted on multiple groups of ROs using multiple receive / transmit beam pairs, with each of the multiple groups of ROs corresponding to one transmission beam of the multiple transmission beams.

[0066] In some configurations, the plurality of ROs 910 includes a first RO 920 (e.g., RO1), a second RO 922 (e.g., RO2), a third RO 924 (e.g., RO3), and a fourth RO 926 (e.g., RO4). As shown in FIG. 9 , in the first RO 920, the UE 104 / 204 transmits data using Tx beam 1 930 and the first node 102 / 202 receives data using Rx beam 1 932. In the second RO 922, the UE 104 / 204 transmits data using Tx beam 1 930 and the first node 102 / 202 receives data using Rx beam 2 934. In the third RO 924, the UE 104 / 204 transmits data using Tx beam 2 936 and the first node 102 / 202 receives data using Rx beam 1 932. In the fourth RO 926, the UE 104 / 204 transmits data using Tx beam 2 936, and the first node 102 / 202 receives the data using Rx beam 2 934. The first node 102 / 202 may identify which Rx beam has the best reception quality by receiving multiple ROs 910 (e.g., the first RO 920, the second RO 922, the third RO 924, and the fourth RO 926). For example, the first node 102 / 202 may identify that the fourth RO 926 has the best reception quality, which determines that the Tx / Rx beam pair used in the fourth RO 926 (Tx beam 2 936 and Rx beam 2 934) is the best Tx / Rx beam pair. In response to determining that the fourth RO 926 has the best reception quality, the first node 102 / 202 (i) determines that Rx beam 2 934 is the best Rx beam for receiving an uplink transmission from the UE 104 / 204, and (ii) utilizes Rx beam 2 934 for receiving a subsequent uplink transmission from the UE 104 / 204. In some configurations, in response to determining that the fourth RO 926 has the best reception quality, the first node 102 / 202 also determines that Tx beam 2 936 is the best Tx beam, which is unknown to the UE 104 / 204.In some examples, the second node 106 / 206 indicates to the UE 104 / 204 that Tx beam 2 936 is the best Tx beam in a subsequent step so that the optimal Tx beam (e.g., Tx beam 2 936) can be used for a subsequent uplink transmission (e.g., Msg. 3).

[0067] In some configurations, the first node 102 / 202 receives the preamble, and the second node 106 / 206 may determine a Tx beam for transmitting the RAR according to the association between the RO and the SSB. In some examples, the second node 106 / 206 uses the Tx beam of the SSB to transmit the RAR, and the SSB is associated with the RO identified by the first node 102 / 202 during the preamble reception process. In some configurations, the best or most suitable Tx beam for the uplink transmission may be indicated in the RAR. In some configurations, some information related to timing advance (TA) determination for a subsequent uplink transmission is transmitted within the RAR. In some configurations, some information related to power control for a subsequent uplink transmission (e.g., Msg. 3 PUSCH) and related information is transmitted within the RAR. In some configurations, the UE 104 / 204 transmits the Msg. 3 PUSCH using the indicated Tx beam.

[0068] In some configurations, after receiving the RAR, the UE 104 / 204 is indicated the best or appropriate Tx beam for uplink transmission. In some examples, the uplink transmission after receiving the RAR may be Msg.3 PUSCH and other uplink transmissions. For each RO used to transmit a preamble, the Tx beam to be used is known to the UE 104 / 204 transmitting the preamble. In some examples, the indication information may be an RO index within an RO group, and the indication information may be included in the RAR. In some configurations, the ROs used in preamble transmission in one RACH attempt may be defined as an RO group. In some configurations, the ROs used to transmit preambles on the same beam within one RACH attempt may be defined as an RO group, and M RO groups are used during one RACH attempt. In some examples, the UE 104 / 204 receives an RAR from the second node indicating a transmission beam that the UE 104 / 204 will use to transmit an uplink transmission, the RAR indicating the transmission beam using an RO index within the RO group.

[0069] In some configurations, the RAR is carried on a PDSCH scheduled by a downlink control information (DCI) format with a cyclic redundancy check (CRC) scrambled by a parameter (e.g., a random access radio network temporary identifier (RA_RNTI)). The RA_RNTI can be calculated according to the time domain location of the RO group. For example, the time domain location of the last RO or the first RO in the RO group can be used to calculate the RA_RNTI. In some examples, the RAR is carried on a downlink channel (e.g., a PDSCH) scheduled by a DCI format with a CRC scrambled by a parameter (e.g., RA_RNTI), where the parameter is determined according to the time domain location of at least one RO (e.g., the first RO, the last RO, etc.) in the RO group.

[0070] In some configurations, if there are N ROs in an RO group (N is a positive integer), then for a given RO index in an RO group: [ka] bits are used. In some examples, [ka] In some configurations, an RO group includes Q ROs, and the number of bits in the RAR used to indicate the RO index within the RO group is [ka] where Q is a positive integer. In some examples, Q may be greater than or equal to N.

[0071] In some other configurations, when there are N ROs in an RO group, for a given RO index in an RO group: [ka] bits are utilized, where N is a positive integer equal to the value of 2. [ka] In some configurations, an RO group includes Q ROs, and the number of bits in the RAR used to indicate the RO index is [ka] where Q is a positive integer and is equal to the value of 2 (e.g., a power of 2). In some examples, Q may be greater than or equal to N.

[0072] In some configurations, in response to receiving the RAR, the UE 104 / 204 determines an RO group according to the RA_RNTI and determines an RO index within the RO group according to the indication information in the RAR. In some examples, in response to receiving the RAR, the UE 104 / 204 further determines that the Tx beam used to transmit the preamble in the RO is the best or suitable Tx beam for uplink transmission (e.g., Msg.3 PUSCH).

[0073] In some configurations, the UE 104 / 204 determines the transmission timing for the uplink transmission after receiving the RAR. In some examples, the UE 104 / 204 receives the RAR from the second node and determines the transmission time for the uplink transmission transmitted by the UE 104 / 204 after receiving the RAR. In some configurations, the uplink transmission TA determination mechanism for the uplink transmission after receiving the RAR (e.g., when the downlink transmitting node is the same as the uplink receiving node, e.g., both are BSs) includes the receive timing taken into account as the transmit timing for transmitting the preamble. After receiving the preamble, the second node 106 / 206 may use the offset between the receive timing and the BS frame boundary as a component of the TA and notify it to the UE 104 / 204 in the RAR. In some configurations, the TA can be determined as the sum of the transmission time between the second node 106 / 206 and the UE 104 / 204 and the transmission time between the UE 104 / 204 and the first node 102 / 202. In some examples, a TA offset (TA_offset) is configured in System Information Block 1 (SIB1) as another component of the TA. The TA_offset can be used to reserve enough time for the BS to switch from Rx to Tx. In some examples, the process time of the first node 102 / 202 to forward information received from the UE 104 / 204 to the second node 106 / 206 is another component of the TA.

[0074] In some examples, the UE 104 / 204 determines a TA for uplink transmission relative to the downlink receive timing at which the RAR is received, and (i) in response to selecting a first RACH mode, the value of the timing advance offset provided in the SIB is omitted to determine the TA, the first RACH mode including the UE 104 / 204 transmitting a PRACH to the first node, and (ii) in response to selecting a second RACH mode, the value of the TA_offset provided in the SIB is used to determine the TA, the second RACH mode including the UE 104 / 204 transmitting a PRACH to the second node.

[0075] In some configurations, in a deployment that forwards uplink transmissions to a second node 106 / 206 by using a first node 102 / 202, when a UE 104 / 204 determines that the current uplink receiving node is the first node 102 / 202, the TA_offset configured in SIB1 is not included in the TA because the first node 102 / 202 does not require Rx / Tx switching time. In some examples, other factors are taken into consideration, such as transmission delays between the first node 102 / 202 and the second node 106 / 206, the timing difference between the reception timing of the first node 102 / 202 and the BS frame boundary, and the processing time of the first node 102 / 202 to forward information received from the UE 104 / 204 to the second node 106 / 206. In some configurations, the uplink transmission after receiving the RAR may be Msg. 3 PUSCH and other uplink transmissions.

[0076] 10 is a diagram 1000 illustrating an example of a cellular communication network including transmission delays, according to some configurations. A first transmission delay T1 is defined as the transmission delay between the second node 106 / 206 and the UE 104 / 204, a second transmission delay T2 is defined as the transmission delay between the first node 102 / 202 and the UE 104 / 204, and a third transmission delay T3 is defined as the transmission delay between the first node 102 / 202 and the second node 106 / 206.

[0077] FIG. 11 is a diagram 1100 illustrating an example timeline of receive and transmit timing according to some configurations. At 1110, a point in time represents a BS frame boundary or a second node 106 / 206 transmit timing or a second node 106 / 206 downlink transmission timing. The downlink transmission arrives at the UE 104 / 204 after a delay of T1. At 1120, point B represents the receive timing of the downlink transmission by the UE 104 / 204. The UE 104 / 204 transmits a preamble to the first node 102 / 202 using the receive timing as the transmit timing for the PRACH transmission. At 1130, point C represents the PRACH receive timing by the first node 102 / 202. In some examples, the BS frame boundary is known to the first node 102 / 202. In some examples, the first node 102 / 202 may learn the sum of the transmission time between the second node 106 / 206 and the UE 104 / 204 (first transmission delay T1) and the transmission time between the UE 104 / 204 and the first node 102 / 202 (second transmission delay T2) based on receiving the preamble, and forward the related information to the second node 106 / 206. In some configurations, the second node 106 / 206 may configure a TA for the UE 104 / 204 by using the RAR. In some examples, the TA of the UE 104 / 204 includes the amount of time that needs to be advanced in a subsequent uplink transmission relative to the reception timing. In some examples, the TA at the UE 104 / 204 allows the uplink transmission to arrive at the network side at a specified time. At 1140, time point D represents the transmitted uplink transmission by the UE 104 / 204.

[0078] In some configurations, there is an ideal backhaul between the second node 106 / 206 and the first node 102 / 202, with no transmission delay between them (e.g., third transmission delay T3=0). In some examples, the receive timing of the first node 102 / 202 is aligned with a BS frame boundary. In some configurations where the RAR includes a TA for an uplink transmission relative to the timing at which the downlink transmission is received, the TA may be determined as the sum of the transmission time between the second node 106 / 206 and the UE 104 / 204 (e.g., first transmission delay T1) and the transmission time between the UE 104 / 204 and the first node 102 / 202 (e.g., second transmission delay T2). For example, the TA value at the UE 104 / 204 may be calculated by the following formula: TA=T1+T2.

[0079] In some configurations, the initial transmission delay T0 is related to at least one of the third transmission delay T3, or the timing difference T4 between the reception timing of the first node 102 / 202 and the BS frame boundary, or the process time of the first node T5. For example, the TA value at the UE 104 / 204 can be calculated by the following formula: TA=T1+T2+T0. In some configurations in which the RAR includes the TA for uplink transmission relative to the time the RAR is received, TA can be determined as the sum of the transmission time between the second node and the UE 104 / 204 (e.g., the first transmission delay T1), the transmission time between the UE 104 / 204 and the first node (e.g., the first transmission delay T2), and an offset (e.g., T0). In some configurations, the offset is at least one of: (i) a transmission delay between the second node and the first node (e.g., the third transmission delay T3); (ii) a timing difference between the reception timing of the first node and the frame boundary of the first node (e.g., T4); or (iii) a processing time of the first node (e.g., T5).

[0080] In some examples, there is an ideal backhaul between the second node 106 / 206 and the first node 102 / 202 such that there is no transmission delay between the first node 102 / 202 and the second node 106 / 206 (e.g., third transmission delay T3=0). In some examples, the third transmission delay T3≠0. In some examples, the fourth transmission delay T4 can be a positive value, a negative value, or 0. When T4=0, it indicates that the receive timing of the first node 102 / 202 is aligned with the BS frame boundary. When T4 is a positive value, it indicates that the BS frame boundary is closer to the receive timing of the first node 102 / 202 than the receive timing of the first node 102 / 202. [ka] If T4 is a negative value, it indicates that the BS frame boundary is later than the first node 102 / 202's received timing. [ka] It shows that progress is being made.

[0081] In some configurations, the UE 104 / 204 determines the transmit power for the preamble transmission. In some configurations, the transmit power determination mechanism for the PRACH transmission can obtain a downlink path loss (PL) according to measurements of a downlink reference signal (e.g., SSB), which can be used to calculate the PRACH transmit power. In some examples, the PRACH transmit power is equal to the sum of the target received power and the downlink PL. In some configurations, in a deployment that forwards uplink transmissions to the second node 106 / 206 by using the first node 102 / 202, the downlink PL and the uplink PL may be different, which prevents the use of the downlink PL to directly determine the uplink transmit power.

[0082] In some configurations, one or more of the path loss adjustment or transmit power adjustment (P_offset) may be configured via system information (e.g., SIB1). In some configurations, the UE 104 / 204 receives the power offset (e.g., P_offset) in the SIB from the second node. In some examples, the PRACH transmit power may be determined as the sum of the target received power, the downlink PL, and P_offset. In some examples, P_offset is determined based on a measurement threshold (e.g., RSRP threshold). As mentioned above, the RSRP threshold is defined for uplink access node determination or selection.

[0083] 12 is a table illustrating an example of a mapping relationship between a synchronization signal reference signal received power (SS-RSRP) measurement result and P_offset according to various configurations. As shown in FIG. 12, in some configurations, if the measurement result is lower than or equal to the measurement threshold, the first node 102 / 202 is determined or selected as the uplink receiving node, and P_offset is used to calculate the transmit power of the preamble. As shown in FIG. 12, in some configurations, if the measurement result is higher than or equal to the measurement threshold, the second node 106 / 206 is determined or selected as the uplink receiving node, and P_offset is not used to calculate the transmit power of the preamble (e.g., P_offset=0).

[0084] In some configurations, other mechanisms may be used to determine the uplink receiving node or RACH mode of the UE 104 / 204. In some configurations, when the uplink receiving node is the first node 102 / 202, P_offset is used to calculate the preamble transmit power, and when the uplink receiving node is a second node 106 / 206 that is not an SSB transmitting node, P_offset is not used to calculate the preamble transmit power (e.g., P_offset=0). For example, in response to the UE 104 / 204 transmitting a preamble to the first node using the transmit power, the UE 104 / 204 determines the transmit power using a power offset (e.g., P_offset), and in response to the UE 104 / 204 transmitting a preamble to the second node using the transmit power, the UE 104 / 204 determines the transmit power without using the power offset (e.g., P_offset=0).

[0085] 13 is a table illustrating another example of a mapping relationship between SS-RSRP and P_offset according to various configurations. In some configurations, more than one P_offset is configured. In some examples, as shown in FIG. 13, (i) if the measurement result is below or equal to or less than measurement threshold 1, P_offset1 is used to calculate the transmit power for the preamble; (ii) if the measurement result is (a) below or equal to or less than measurement threshold 2 and (b) greater than or equal to measurement threshold 1, P_offset2 is used to calculate the transmit power for the preamble; and (iii) if the measurement result is greater than or equal to measurement threshold 2 or greater than measurement threshold 2, P_offset is not used to calculate the transmit power for the preamble (e.g., P_offset=0).

[0086] In some configurations, the UE 104 / 204 determines the transmit power for the Msg.3 PUSCH transmission. In some configurations, according to the transmit power determination mechanism for the Msg.3 transmission, a first list of delta values ​​(e.g., {-1,...,6}) is defined, an RRC parameter is used to indicate one delta (e.g., Delta1) from the list, and the power of the Msg.3 transmission is determined as the sum of the transmit power of the preamble and Delta1. In some configurations, there may be a larger power difference between the preamble and Msg.3. In some configurations, a second list (e.g., a new list) of delta values ​​with greater granularity is defined (e.g., {-20,-10,0,10,20,30}), an indication is used to indicate one delta (e.g., Delta2) from the new list, and if the UE 104 / 204 determines that the uplink receiving node is the first node 102 / 202, the delta value from the second list may be used to determine the power of the Msg.3 transmission.

[0087] In some configurations, the UE 104 / 204 receives the first and second delta value lists from the second node and determines a transmit power for transmitting an Msg.3 uplink (e.g., PUSCH) transmission according to one of the first and second delta value lists. In some examples, determining a transmit power for transmitting an Msg.3 uplink transmission according to one of the first and second delta value lists is based on which RACH mode (e.g., the first and second RACH modes) the UE 104 / 204 selected.

[0088] In some configurations, the UE 104 / 204 receives an indication from the second node. In response to selecting a first RACH mode, a delta value from a first list of delta values ​​is determined in accordance with the indication, the first RACH mode including the UE 104 / 204 transmitting a PRACH to the first node. In response to selecting a second RACH mode, a delta value from a second list of delta values ​​is determined in accordance with the indication, the second RACH mode including the UE 104 / 204 transmitting a PRACH to the second node. The UE 104 / 204 determines a transmit power using the delta value and transmits an Msg.3 uplink transmission to the first node using the transmit power.

[0089] In some configurations, Delta2 is indicated via RAR or SIB1 and is used to calculate the transmit power of Msg.3 instead of Delta1, such that the power of the Msg.3 transmission is determined as the sum of the transmit power of the preamble and Delta2.

[0090] In some configurations, Delta2 is indicated via RAR or SIB1 and is used together with Delta1 to calculate the transmit power of Msg.3, such that the power of the Msg.3 transmission is determined as the sum of the transmit powers of the preamble, Delta1, and Delta2.

[0091] In some configurations, if the UE 104 / 204 determines that the uplink receiving node is the first node 102 / 202, a power offset is defined and utilized to determine the power of the Msg.3 transmission, such that the transmit power of Msg.3 is determined as the sum of the transmit power of the preamble, Delta1, and the power offset.

[0092] 7, the second node 106 / 206 transmits three SSBs (e.g., the one or more backhaul links 720) (e.g., cell SSBs) to cover the entire cell. To cover a predetermined range, the RN 710 transmits four SSBs (e.g., one or more access links 730) (e.g., refined SSBs) to allow the UE 104 / 204 to access the cell via either the second node 106 / 206 or the RN 710. In some configurations, accessing the cell via the RN 710 depends on one or more factors.

[0093] In some configurations, the RN 710 may forward only the cell-SSB received from the second node 106 / 206 (e.g., cell-SSB0) so that more than one refined SSB for the access link (e.g., refined SSB#0, refined SSB#1, refined SSB#2, refined SSB#3, etc.) carry the same SSB index (e.g., SSB index#0). In some examples, the SSB index information is carried by at least one of a PBCH demodulation reference signal (DMRS) sequence and a PBCH payload. In some examples, only SSB#0 resources may be used to transmit the refined SSBs, with different refined SSBs being transmitted at different periodicities.

[0094] 14 is a diagram 1400 illustrating an example of SSB transmission according to various configurations. Diagram 1400 includes a cell-specific configured periodicity 1410 of SSB transmission and an actual periodicity 1420 of SSB transmission. In some examples, the cell-specific configured periodicity 1410 of SSB transmission is 5 ms, and in order to transmit four refined SSBs (Refined SSB#0 1430, Refined SSB#1 1432, Refined SSB#2 1434, and Refined SSB#3 1436) within the resource of SSB index #0, the actual periodicity 1420 of the SSB transmission (e.g., refined SSB transmission) is extended by a factor of four (e.g., each refined SSB 1430, 1432, 1434, and 1436 is transmitted with an independent periodicity). In some configurations, all refined SSBs 1430, 1432, 1434, and 1436 carry the same SSB index (e.g., SSB index #0), so both the PBCH DMRS sequence and the PBCH payload used by refined SSBs 1430, 1432, 1434, and 1436 may indicate only SSB index #0. In some configurations, additional indication aspects distinguish between refined SSBs 1430, 1432, 1434, and 1436. As shown in FIG. 14, in the refined SSB actual transmission period 1420, different refined SSBs 1430, 1432, 1434, and 1436 are in different radio frames and half-frames. In some configurations, the refined SSB index may be indicated by binding a system frame number (SFN) and a half-frame.

[0095] 15 is a table illustrating an example of a mapping relationship between refined SSB index, SFN, and half frame according to various configurations. In some configurations, P is the actual transmission period for the refined SSB frame. In some examples, P is equal to a value of 2.

[0096] In some configurations, the transmission period of the cell-SSB is 10 ms or more, whereby different refined SSBs are placed in different system frames. In some configurations, the refined SSB index may be indicated by the SFN.

[0097] 16 is a table illustrating another example of a mapping relationship between refined SSB indexes and SFNs according to various configurations. As shown in FIG. 16, P1 is the actual transmission period of the refined SSB, P2 is the transmission period of the cell-SSB, and N is the refined SSB index.

[0098] In some configurations, the actually transmitted refined SSBs are indicated to the UE 104 / 204. In some examples, the actually transmitted cell-SSB indication received from the second node 106 / 206 may be forwarded directly by the RN 710 such that the UE 104 / 204 receives that SSB#0, SSB#1, and SSB#2 were actually transmitted and that valid ROs are circularly associated with SSB#0, SSB#1, and SSB#2. In some examples, the actual transmitted SSBs for the access link are indicated by the RN 710 such that the signaling "ssb-PositionsInBurst" is updated before forwarding. For example, the actual transmitted SSB indications received from the second node 106 / 206 are SSB#0, SSB#1, and SSB#2, but only SSB#0 is transmitted by itself, thereby causing the RN 710 to indicate that only SSB#0 was actually transmitted and that all valid ROs are associated with SSB#0.

[0099] In some configurations, the RO associated with the forwarded SSB (e.g., SSB0) is used for preamble transmission, while other ROs are defined as invalid ROs and may be used for other UL transmissions. In some configurations, an additional association between the refined beam and the RO corresponding to SSB0 is defined.

[0100] Figure 17 is a diagram 1700 illustrating an example of a mapping relationship between refined SSBs 1430, 1432, 1434, and 1436 and ROs 1710, 1712, 1714, and 1716 according to various configurations. As shown in Figure 17, all refined SSBs 1430, 1432, 1434, and 1436 are transmitted on resources for SSB index #0, and refined SSBs 1430, 1432, 1434, and 1436 are cyclically associated with ROs 1710, 1712, 1714, and 1716 associated with SSB index #0.

[0101] In some configurations, the RN 710 may forward only the cell-SSB (e.g., cell-SSB0) received from the second node 106 / 206, and more than one refined SSB for the access link carries the same SSB index (e.g., refined SSBs 1430, 1432, 1434, and 1436 all carry SSB index #0). In some examples, the SSB index information is carried by at least one PBCH DMRS sequence and the PBCH payload. In some examples, resources for other SSB indices may also be used for refined SSB transmissions.

[0102] FIG. 18 is a diagram 1800 illustrating an example of transmission of refined SSBs 1430, 1432, 1434, and 1436 according to various configurations. In some configurations, diagram 1800 includes a cell-specific configured period 1410 of SSB transmission that is equal to the actual period 1420 of the refined SSB transmission. In some configurations, refined SSBs 1430, 1432, 1434, and 1436 are transmitted on resources for different SSB indices (e.g., SSB index #0, SSB index #1, SSB index #2, SSB index #3, etc.). In some configurations, a ☐ symbol ... [ka] An additional mechanism is defined to indicate the index of the refined SSB (eg, PBCH payload) so that bits are required.

[0103] In some configurations, the RN 710 can generate SSBs (e.g., SSB1, SSB2, etc.) that are not received from the second node 106 / 206, and different refined beams can carry different refined SSB indices. As shown in Figure 18, SSB resources can be used for refined beam transmissions with corresponding SSB indices. In some examples, the refined SSB index can be indicated via at least one of the PBCH DMRS sequence and the PBCH payload.

[0104] In some configurations, the actually transmitted refined SSBs may be indicated to the UE 104 / 204. In some examples, the actually transmitted SSBs for the access link are indicated by the RN 710 so that the signaling "ssb-PositionsInBurst" is updated before forwarding. For example, the actual transmitted SSB indications received from the second node 106 / 206 are SSB#0, SSB#1, and SSB#2, but refined SSB#0, SSB#1, SSB#2, and SSB#3 are transmitted by themselves, thereby indicating to the RN that refined SSB#0, SSB#1, SSB#2, and SSB#3 were actually transmitted and that the valid ROs are circularly associated with refined SSB#0, SSB#1, SSB#2, and SSB#3.

[0105] In some configurations, the refined SSB index selected by the UE 104 / 204 pursuant to the PRACH reception may be identified by the RN 710 and indicated to the second node 106 / 206. For example, information (e.g., the refined SSB index) may be indicated via a control link between the RN 710 and the second node 106 / 206, which may indicate to the RN 710 the beam for a subsequent DL transmission to the UE 104 / 204 accordingly.

[0106] 19 is a diagram 1900 illustrating an example method for radio resource control (RRC) setup according to various configurations. At 1910, the UE 104 / 204 is RRC idle (e.g., RRC_IDLE). At 1912, a RACH procedure is performed. In some configurations, the RACH procedure at 1912 includes the UE 104 / 204 transmitting an RRC setup request (e.g., Msg3 "RRCSetupRequest") to the second node 106 / 206 at 1914. In some configurations, the RACH procedure at 1912 includes the UE 104 / 204 receiving an RRC setup (e.g., Msg4 "RRCSetup") message from the second node 106 / 206 at 1916. At 1920, the UE 104 / 204 is RRC connected (e.g., RRC_CONNECTED). At 1922, the UE 104 / 204 transmits an RRC setup complete (e.g., Msg5 "RRCSetupComplete") message to the second node 106 / 206. In some examples, the RRC setup complete message notifies the second node 106 / 206 that the UE 104 / 204 has completed the RRC setup. At 1924, the UE 104 / 204 receives a capability inquiry (e.g., "UECapabilityEnquiry") from the second node 106 / 206. At 1926, the UE 104 / 204 transmits the UE 104 / 204's capability information (e.g., "UECapabilityInformation") to the second node 106 / 206. At 1928, the UE 104 / 204 receives an RRC reconfiguration (e.g., "RRCReconfiguration") from the second node 106 / 206. At 1930, the UE 104 / 204 transmits an RRC reconfiguration complete (eg, "RRCReconfigurationComplete") message to the second node 106 / 206.

[0107] In some configurations, as shown in FIG. 19, after the UE 104 / 204 performs a RACH procedure (e.g., a four-step RACH procedure), the network schedules an Msg5 PUSCH transmission to complete RRC setup. In some configurations, the network performs an RRC reconfiguration (e.g., 1928) according to the capability information of the UE 104 / 204. In some examples, some functions (which need to be determined based on the capability information of the UE 104 / 204) cannot be configured before the capability information of the UE 104 / 204 is reported. In some configurations, before the first RRC configuration (e.g., the RRCReconfiguration message is received by the UE 104 / 204 in 1928), DCI formats other than 0_0 cannot be used for UL scheduling, and as a result, an Msg5 PUSCH transmission (scheduled by DCI format 0_0 with a CRC scrambled by a parameter (e.g., Cell Radio Network Temporary Identifier (C-RNTI)) cannot be repeatedly scheduled.

[0108] In some configurations, the Msg5 PUSCH transmission is scheduled by a DCI format other than DCI format 0-0 (e.g., DCI format 0-1 or 0-2) so that coverage of the Msg5 PUSCH transmission can be enhanced by using repeated transmissions for the Msg5 PUSCH. In some configurations, the UE 104 / 204 may report relevant capability information of the UE 104 / 204 in advance, for example, via Msg3, so that a corresponding configuration can be configured by the network according to the reported capability information of the UE 104 / 204. In some configurations, the UE 104 / 204 may determine the size of the information field of a DCI format other than DCI format 0-0 and further determine the transmission parameter configuration of the scheduled PUSCH according to the indication in the information field. In some configurations, the reported capability information of the UE 104 / 204 includes at least one of: (i) PUSCH repetition type A; (ii) PUSCH repetition type B; (iii) supported hybrid automatic repeat request-acknowledgement (HARQ-ACK) codebook type (e.g., dynamic HARQ-ACK codebook and / or quasi-static HARQ-ACK codebook); (iv) PUSCH multiple-input / multiple-output (MIMO) transmission capability (e.g., codebook-based PUSCH transmission and / or non-codebook-based PUSCH transmission); or (v) a maximum number of orthogonal frequency division multiplexing (OFDM) symbols for UL frontloading DMRS (1 or 2).

[0109] In some configurations, the UE 104 / 204 may report request information for Msg5 PUSCH transmission with repetition, whereby the Msg5 PUSCH transmission with repetition may be scheduled by DCI format 0-0, and the repetition factor may be indicated via information in the DCI format or may be configured in Msg2 or SIB1. In some configurations, the Msg5 PUSCH transmission with repetition may be scheduled by a DCI format other than DCI format 0-0 (e.g., DCI format 0-1 or 0-2), and some default capability information of the UE 104 / 204 related to the PUSCH transmission may be specified. In some configurations, the default capability information of the UE 104 / 204 includes at least one of: (i) supporting PUSCH repetition type A; (ii) supporting PUSCH repetition type B; (iii) supporting at least one of HARQ-ACK codebook types (e.g., dynamic HARQ-ACK codebook and / or quasi-static HARQ-ACK codebook); (iv) supporting at least one of PUSCH MIMO transmission modes (e.g., codebook-based PUSCH transmission and / or non-codebook-based PUSCH transmission); or (v) a maximum number of OFDM symbols (1 or 2) for UL frontloaded DMRS.

[0110] In some configurations, the UE 104 / 204 reports its PUSCH repetition transmission capability (e.g., PUSCH repetition type A) in a PUSCH scheduled by DCI format 0-0 with a CRC scrambled by a parameter (e.g., C-RNTI, etc.) by using a PRACH transmission, information in Msg3 (e.g., RRC or medium access control (MAC) layer signaling), or RRC signaling (e.g., UE 104 / 204 capability information). In some configurations, in response to the UE 104 / 204 requesting a repeat transmission on a PUSCH scheduled by DCI format 0-0 with a CRC scrambled by a parameter (e.g., C-RNTI) by using a PRACH transmission, information in Msg3 (RRC or MAC layer signaling), or RRC signaling (e.g., UE 104 / 204 capability information), the UE 104 / 204 receives a repetition factor for the PUSCH transmission by the DCI format that schedules the PUSCH. In some examples, the two most significant bits (MSBs) of the modulation and coding scheme (MCS) field are used to indicate the repetition factor. For example, one of the four RRC-configured repetition factors may be indicated by the two MSBs.

[0111] In some configurations, an information field of a DCI format, such as a time domain resource allocation (TDRA) field or a frequency domain resource allocation (FDRA) field, may be used to indicate the repetition factor. In some configurations, the flexibility of the information field is affected. For example, the indication range of 32 MCSs in the original 5-bit MCS field is reduced to 8 MCSs in response to the two MSBs of the MCS field being used to indicate the repetition factor. In some configurations, scheduling modes are defined to include a repetitive scheduling mode and a non-repetitive scheduling mode. In some examples, for a PUSCH transmission scheduled by DCI format 0-0 in the repetitive scheduling mode, at least some bits of the related information field of DCI format 0-0 are interpreted as an indication of the repetition factor. In some examples, for a PUSCH transmission scheduled by DCI format 0-0 in the non-repetitive scheduling mode, the related information field of DCI format 0-0 does not include an indication of the repetition factor. In some configurations, a condition indicating a scheduling mode (e.g., a repetitive scheduling mode and a non-repetitive scheduling mode) is defined. In some examples, when a recurrence scheduling mode is indicated or determined, some bits of the related information field (such as the MCS field) of DCI format 0-0 are reinterpreted as recurrence factor information, thereby improving the flexibility of PUSCH scheduling.

[0112] In some configurations, the scheduling mode (e.g., repeating scheduling mode and non-repeating scheduling mode) of a PUSCH scheduled by DCI format 0-0 is determined according to the scheduling mode (e.g., DCI format 0-1 or 0-2) of another PUSCH scheduled by non-DCI format 0-0 (regardless of whether at least some bits of the information field of DCI format 0-0 are reinterpreted as a repetition factor). In some configurations, non-DCI format 0-0 is the most recent non-DCI format before DCI format 0-0. In some examples, in response to a PUSCH being scheduled with repetition by non-DCI format 0-0, the scheduling mode (e.g., repeating scheduling mode and non-repeating scheduling mode) of a PUSCH scheduled by DCI format 0-0 is also scheduled with repetition (e.g., repeating scheduling mode) such that the repetition factor is indicated by at least some bits of the information field of DCI format 0-0. In some configurations, a time interval threshold is defined such that if the time interval between DCI format 0-0 and the latest non-DCI format 0-0 exceeds the time interval threshold, a default scheduling mode (e.g., one of the recurring scheduling mode or the non-recurring scheduling mode) is selected. In some examples, if the time interval between DCI format 0-0 and the latest non-DCI format 0-0 does not exceed the time interval threshold, the scheduling mode (e.g., the recurring scheduling mode or the non-recurring scheduling mode) of the PUSCH scheduled by DCI format 0-0 is determined according to the scheduling mode of the PUSCH scheduled by the latest non-DCI format 0-0.

[0113] In some configurations, the scheduling mode (e.g., recurring scheduling mode and non-recurring scheduling mode) of a PUSCH scheduled by a first DCI format 0-0 follows the scheduling mode of another PUSCH scheduled by a second DCI format 0-0. In some configurations, the second DCI format 0-0 is the most recent DCI format before the first DCI format 0-0. In some examples, a time interval threshold is defined such that if the time interval between the first DCI format 0-0 and the second DCI format 0-0 exceeds the time interval threshold, a default scheduling mode (e.g., one of the recurring scheduling mode or the non-recurring scheduling mode) is selected. In some examples, if the time interval between the first DCI format 0-0 and the second DCI format 0-0 does not exceed the time interval threshold, the scheduling mode of a PUSCH scheduled by the first DCI format 0-0 is determined based on the scheduling mode of another PUSCH scheduled by the second DCI format 0-0.

[0114] In some configurations, a scheduling mode (e.g., a recurring scheduling mode and a non-recurring scheduling mode) of a first PUSCH scheduled by the first DCI format 0-0 is determined according to indication information carried in a second PUSCH scheduled by the second DCI format. In some configurations, the second PUSCH is the most recent PUSCH, and the second PUSCH carries indication information before the first PUSCH. In some configurations, the indication information includes RRC signaling or MAC layer signaling (e.g., MAC CE, etc.).

[0115] In some configurations, the scheduling mode (e.g., recurring scheduling mode and non-recurring scheduling mode) of the PUSCH scheduled by DCI format 0-0 is determined according to an indication bit of DCI format 0-0. In some examples, if the first number of bits of DCI format 1_0 before padding is greater than the second number of bits of DCI format 0_0 before padding, one bit for indication is added after the padding bits of DCI format 0_0. In some configurations, one value of the indication bit (e.g., 1 or 0) indicates that the PUSCH transmission is in the recurring scheduling mode, such that at least some bits of the related information field are interpreted as a recurrence factor indication, and another value of the indication bit (e.g., 0 or 1) indicates that the PUSCH transmission is in the non-recurring scheduling mode, such that the indication information of the DCI format does not include an indication of the recurrence factor.

[0116] In some configurations, the scheduling mode (e.g., recurring scheduling mode and non-recurring scheduling mode) of the PUSCH scheduled by DCI format 0-0 is determined according to the latest downlink measurement result. In some configurations, the latest downlink measurement result is reported to the second node 106 / 206 before DCI format 0-0. In some configurations, the relationship between the measurement result and the scheduling mode is predefined or configured by the second node 106 / 206. In some examples, according to the reported measurement result, both the second node 106 / 206 and the UE 104 / 204 can determine the same scheduling mode for subsequent PUSCH scheduling so that the UE 104 / 204 can correctly process the information field of DCI format 0-0.

[0117] While various configurations of the present disclosure have been described above, it should be understood that they are presented by way of example only, and not by way of limitation. Similarly, various diagrams may depict example architectures or configurations provided to enable those skilled in the art to understand example features and functionality of the present solutions. However, such persons will understand that the solutions are not limited to the example architectures or configurations illustrated, but can be implemented using various alternative architectures and configurations. Furthermore, as will be understood by those skilled in the art, one or more features of one configuration can be combined with one or more features of another configuration described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the example configurations described above.

[0118] It is also understood that any reference herein to an element using a designation such as "first," "second," etc., generally does not limit the quantity or order of those elements. Rather, these designations may be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to a first and a second element does not imply that only two elements can be used or that the first element must precede the second element in any way.

[0119] Additionally, those skilled in the art will understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, and symbols that may be referred to in the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0120] Those skilled in the art will further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods, and functions described in connection with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of the two), firmware, various forms of programs or design code incorporating instructions (which may be referred to herein for convenience as “software” or “software modules”), or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these techniques, depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, and such implementation decisions do not cause a departure from the scope of the present disclosure.

[0121] Furthermore, those skilled in the art will understand that the various example logic blocks, modules, devices, components, and circuits described herein can be implemented in or performed by an integrated circuit (IC), which may include 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, or any combination thereof. The logic blocks, modules, and circuits may further include an antenna and / or transceiver for communicating with various components within a network or device. The general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration for performing the functions described herein.

[0122] If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, including any medium that can be enabled to transfer a computer program or code from one place to another. A storage medium can be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0123] As used herein, the term "module" refers to software, firmware, hardware, and any combination of these elements for performing the related functions described herein. Additionally, for purposes of explanation, various modules are described as individual modules, however, one skilled in the art will recognize that two or more modules may be combined to form a single module that performs related functions according to the configuration of the present solution.

[0124] Additionally, memory or other storage, as well as communication components, may be used in implementing the solution. It will be understood that, for clarity, the above description describes the implementation of the solution with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements, or domains may be used without detracting from the solution. For example, functionality illustrated as being performed by separate processing logic elements or controllers may be performed by the same processing logic element or controller. Accordingly, references to specific functional units do not represent a strict logical or physical structure or organization, but merely to suitable means for providing the described functionality.

[0125] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. 1. A wireless communication method, comprising: a wireless communication device performing a Random Access Channel (RACH) procedure involving a first node and a second node, the wireless communication device receiving downlink data from the second node; the wireless communication device communicating with the second node via the first node; A wireless communication method comprising:

2. the wireless communication device selecting a first RACH mode or a second RACH mode; the first RACH mode includes the wireless communication device transmitting a Physical Random Access Channel (PRACH) to the first node; 2. The method of claim 1, wherein the second RACH mode includes the wireless communication device transmitting the PRACH to the second node.

3. Selecting the first RACH mode or the second RACH mode includes: selecting the first RACH mode in response to the wireless communication device determining that a measurement of transmissions received from the second node is less than or equal to a threshold; or selecting the second RACH mode in response to the wireless communication device determining that the measurement of the transmission received from the second node is greater than or equal to the threshold. The method of claim 2 , comprising:

4. Selecting the first RACH mode or the second RACH mode includes: selecting the first RACH mode in response to the wireless communication device determining that a measurement result of a transmission received from the second node is within a range; or selecting the second RACH mode in response to the wireless communication device determining that the measurement result of the transmission received from the second node is outside the range. The method of claim 2 , comprising:

5. Selecting the first RACH mode or the second RACH mode includes: selecting one of the first RACH mode or the second RACH mode in response to the RACH procedure failing with respect to a number of attempts using the other of the first RACH mode or the second RACH mode, the number of attempts being equal to or greater than a threshold. The method of claim 2 , comprising:

6. Selecting the first RACH mode or the second RACH mode includes: selecting one of the first RACH mode or the second RACH mode in response to a power of a preamble transmission in the other of the first RACH mode or the second RACH mode reaching a predetermined value, the predetermined value comprising a maximum transmit power of the preamble transmission configured by the second node. The method of claim 2 , comprising:

7. 3. The method of claim 2, wherein the first RACH mode or the second RACH mode is selected for a synchronization signal / PBCH block (SSB) or a channel state information-reference signal (CSI-RS).

8. the wireless communication device selecting a first transmission link for the RACH procedure or a second transmission link for a Physical Random Access Channel (PRACH) transmission; the first transmission link is between the wireless communication device and the first node; 10. The method of claim 1, wherein the second transmission link is between the wireless communication device and the second node.

9. 10. The method of claim 1, comprising selecting a receive / transmit beam pair by trying a plurality of receive / transmit beam pairs, the receive / transmit beam pair being used to send an uplink transmission from the wireless communication device to the first node.

10. 10. The method of claim 9, wherein the wireless communication device transmits a preamble to a network using a transmission beam of each of the plurality of receive / transmit beam pairs, each of the plurality of receive / transmit beam pairs including one of a plurality of receive beams and one of a plurality of transmit beams, the transmission beam being one of the plurality of transmission beams, and the network receives the preamble using a receive beam of each of the plurality of receive / transmit beam pairs, the receive beam being one of the plurality of receive beams.

11. the preamble is transmitted in a group of RACH opportunities (ROs) using the plurality of receive / transmit beam pairs, each RO in the group of ROs corresponding to a respective one of the plurality of receive / transmit beam pairs; or 11. The method of claim 10, wherein the preamble is transmitted in multiple groups of RACH opportunities (ROs) using the multiple receive / transmit beam pairs, each of the multiple groups of ROs corresponding to a transmission beam among the multiple transmission beams.

12. 2. The method of claim 1, comprising: the wireless communication device receiving a random access response (RAR) from the second node, the RAR indicating a transmission beam using which the wireless communication device transmits an uplink transmission, the RAR indicating the transmission beam using a RACH opportunity (RO) index within an RO group.

13. The RAR is carried on a downlink channel scheduled by a downlink control information (DCI) format having a cyclic redundancy check (CRC) scrambled by a parameter; The method of claim 12 , wherein the parameter is determined according to a time-domain location of at least one RO in the RO group.

14. The RO group comprises Q ROs; The number of bits in the RAR used to indicate the RO index within the RO group is: [Equation 1] 14. The method of claim 13, wherein Q can be determined using:

15. The RO group comprises Q ROs; The number of bits in the RAR used to indicate the RO index is [Equation 2] 14. The method of claim 13, wherein Q can be determined using Q = Q + ...

16. receiving, by the wireless communication device, a random access response (RAR) from the second node; determining, by the wireless communication device, a transmission time for an uplink transmission to be transmitted by the wireless communication device after receiving the RAR; The method of claim 1 , comprising:

17. The wireless communication device further includes determining a timing advance (TA) for the uplink transmission relative to a downlink receive timing at which the RAR is received; In response to selecting the first RACH mode, a timing advance offset value provided in a system information block (SIB) is omitted for determining the TA; 17. The method of claim 16, wherein, in response to selecting a second RACH mode, the value of the timing advance offset provided in the SIB is used to determine the TA, the first RACH mode including the wireless communication device transmitting a Physical Random Access Channel (PRACH) to the first node, and the second RACH mode including the wireless communication device transmitting the PRACH to the second node.

18. 17. The method of claim 16, wherein the RAR includes a timing advance (TA) for the uplink transmission relative to a time the RAR is received, and the TA can be determined as a sum of a transmission time between the second node and the wireless communication device and a transmission time between the wireless communication device and the first node.

19. The RAR may include a Timing Advance (TA) for the uplink transmission relative to a time at which the RAR is received, and the TA may be determined as the sum of a transmission time between the second node and the wireless communication device, a transmission time between the wireless communication device and the first node, and an offset, the offset being: a transmission delay between the second node and the first node; the timing difference between the receive timing of the first node and a frame boundary of the first node; or the processing time of the first node 17. The method of claim 16, wherein the at least one of

20. The method of claim 1 , comprising determining a transmit power for transmitting the preamble.

21. 21. The method of claim 20, comprising the wireless communications device receiving a power offset in a system information block (SIB) from the second node, the power offset comprising at least one of a path loss adjustment or a transmit power adjustment, and the transmit power being a sum of a target received power, a downlink path loss, and the power offset.

22. The method of claim 21 , wherein the power offset is determined based on a measurement threshold.

23. the wireless communication device determining the transmit power using a power offset, the wireless communication device transmitting the preamble to the first node using the transmit power; the wireless communication device determining the transmit power without using the power offset, the wireless communication device transmitting the preamble to the second node using the transmit power; 21. The method of claim 20, comprising:

24. receiving, by the wireless communication device, a first list of delta values ​​and a second list of delta values ​​from the second node; determining a transmit power for transmitting a Msg. 3 uplink transmission in accordance with one of the first list of delta values ​​and the second list of delta values; The method of claim 1 , comprising:

25. receiving, by the wireless communication device, an indication from the second node; in response to selecting a first RACH mode, a delta value from the first list of delta values ​​is determined according to the indication; in response to selecting a second RACH mode, a delta value from said second list of delta values ​​is determined according to said indication; determining the transmit power using the delta value; the wireless communication device transmits the Msg. 3 uplink transmission to the first node using the transmit power, the first RACH mode including the wireless communication device transmitting a Physical Random Access Channel (PRACH) to the first node, and the second RACH mode including the wireless communication device transmitting the PRACH to the second node; 25. The method of claim 24, comprising:

26. 10. A wireless communication device comprising at least one processor and a memory, the at least one processor configured to read code from the memory to implement the method of claim 1.

27. 10. A computer program product having stored thereon a computer readable program medium code that, when executed by at least one processor, causes the at least one processor to perform the method of claim 1.

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