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WO-2026091073-A1 - A METHOD FOR RANDOM ACCESS CHANNEL TRANSMISSION AND RECEPTION

WO2026091073A1WO 2026091073 A1WO2026091073 A1WO 2026091073A1WO-2026091073-A1

Abstract

This disclosure relates generally to a method, device, and system wireless communication. One method performed by a wireless device may include: transmitting, to a wireless communication node, a first message to initiate a random access procedure, the first message comprising N preambles which are transmitted in N random access channel occasions (ROs) using N different spatial filters, wherein for each i from 0 to (N-1), an i-th preamble is transmitted in an i-th RO using an i-th spatial filter, and wherein N and i are integers.

Inventors

  • LIU, XING
  • HAN, Xianghui
  • ZHANG, JUNFENG
  • ZHOU, Shuai

Assignees

  • ZTE CORPORATION

Dates

Publication Date
20260507
Application Date
20241101

Claims (20)

  1. A method for wireless communication, performed by a wireless device, the method comprising: transmitting, to a wireless communication node, a first message to initiate a random access procedure, the first message comprising N preambles which are transmitted in N random access channel occasions (ROs) using N different spatial filters, wherein for each i from 0 to (N-1) , an i-th preamble is transmitted in an i-th RO using an i-th spatial filter, and wherein N and i are integers.
  2. The method of claim 1, wherein: the N ROs are selected from an RO group, the RO group is pre-configured; and a size of the RO group is M, M being an integer greater than or equal to N.
  3. The method of claim 1, wherein the N ROs are selected from a target RO group among one or more RO groups of different sizes, and wherein the target RO group having an optimal size determined by N.
  4. The method of claim 2, wherein the N ROs are selected from first N ROs in the RO group.
  5. The method of claim 2, wherein the RO group is pre-configured into at least one sub-group, the N ROs are in a target sub-group in the at least one sub-group, and wherein the target sub-group is selected based on N.
  6. The method of any one of claims 1-5, wherein N is determined based on a measurement result of a Reference Signal (RS) .
  7. The method of claim 6, wherein there are one or more measurement result ranges, and wherein N is determined based on a first range in the one or more measurement result ranges, wherein the measurement result of the RS falls into the first range.
  8. The method of claim 7, wherein the one or more measurement result ranges are formed by one or more measurement threshold.
  9. The method of any one of claims 1-5, wherein N is determined based on at least one of: a transmission antenna configuration of the wireless device; a number of transmission spatial filters supported by the wireless device; or a UE capability of the wireless device.
  10. The method of any one of claims 1-9, wherein for the each i from 0 to (N-1) : an i-th RO is associated with a corresponding i-th preamble set comprising at least one preamble; and the i-th preamble is a j-th preamble in the corresponding i-th preamble set, j being an integer.
  11. The method of claim 10, where the corresponding i-th preamble set is preconfigured.
  12. The method of any one of claims 1-5, wherein at least two ROs in the N ROs are located at different frequency resources.
  13. The method of any one of claims 1-5, wherein each of the N preambles is different from others.
  14. The method of any one of claims 1-5, further comprising: determining, from a preamble set, a first preamble of the N preambles to be transmitted in a first RO of the N ROs, wherein the preamble set is sorted; and sequentially selecting preambles following the first preamble in the preamble set as remaining (N-1) preambles of the N preambles; or sequentially selecting preambles preceding the first preamble in the preamble set as the remaining (N-1) preambles of the N preambles.
  15. The method of claim 14, wherein determining the first preamble comprises: determining the first preamble based on a local policy; or determining the first preamble based on a pre-configuration via the wireless communication node.
  16. The method of claim 1, further comprising: receiving, from the wireless communication node, a second message as a response to the first message, the second message comprising at least one of: a control portion; or a data portion indicated by the control portion, the second message carrying an optimal spatial filter indicator indicating an optimal spatial filter that is selected from the N different spatial filters and is to be used by the wireless device in subsequent uplink transmissions.
  17. The method of claim 16, wherein the second message comprises a Msg2 in the random access procedure, and the control portion comprises a Downlink Control Information (DCI) .
  18. The method of claim 16, wherein the subsequent uplink transmissions comprising at least one of: a transmission of Msg3 Physical Uplink Shared Channel (PUSCH) in the random access procedure; or a Physical Uplink Control Channel (PUCCH) associated with Msg4 in the random access procedure.
  19. The method of any one of claims 16-18, wherein the optimal spatial filter indicator is carried in an optimal spatial filter indicator field of the control portion, and a size of the optimal spatial filter field is determined based on N.
  20. The method of any one of claims 16-18, wherein at least partial of the optimal spatial filter indicator is indicated via at least one of: a field in the control portion with other type of information, the other type of information comprising at least one of: a frequency domain resource assignment; a time domain resource assignment; or a Modulation and Coding Scheme (MCS) ; a Random Access -Radio Network Temporary Identifier (RA-RNTI) , which is used for scrambling a Cyclic Redundancy Check (CRC) of the control portion; or a Random Access Preamble Identifier (RAPID) in the data portion.

Description

A METHOD FOR RANDOM ACCESS CHANNEL TRANSMISSION AND RECEPTION TECHNICAL FIELD This disclosure is directed generally to wireless communications, and particularly to a method, device, and system for random access in a wireless communication network, such as 4G, 5G, and 6G wireless communication network. BACKGROUND Efficiency in random access is an important factor in wireless communications due to its impact on network performance and user experience. An efficient random access mechanism minimizes network access latency for a wireless device such as a User Equipment (UE) , reduces communication overhead while optimizing power consumption for both devices and network infrastructure. This efficiency leads to improved overall throughput and reliability. As wireless networks continue to expand and evolve, efficient random access becomes even more crucial for supporting the growing number of connected devices effectively. Further, it ensures better user experience through faster connection establishment and fewer connection failures, while providing economic benefits by lowering operational costs for network operators and extending the battery life of connected devices. SUMMARY This disclosure is directed to a method, device, and system for wireless communication, and more specifically, for random access using multiple beams in a wireless communication system, such as 4G, 5G, and 6G wireless communication network. In some embodiments, a method performed by a wireless device is disclosed. The method may include: transmitting, to a wireless communication node, a first message to initiate a random access procedure, the first message comprising N preambles which are  transmitted in N random access channel occasions (ROs) using N different spatial filters (or N different transmission beams) , wherein for each i from 0 to (N-1) , an i-th preamble is transmitted in an i-th RO using an i-th spatial filter, and wherein N and i are integers. The wireless communication node may include a base station. In some embodiments, a method performed by a network node is disclosed. The method may include: receiving, from a wireless device, a first message for initiating a random access procedure, the first message comprising N preambles which are transmitted in N random access channel occasions (ROs) using N different spatial filters, wherein for each i from 0 to (N-1) , an i-th preamble is transmitted in an i-th RO using an i-th spatial filter, and wherein N and i are integers. The wireless device may include a User Equipment (UE) . In some embodiments, there is a network node or a UE/wireless device comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement any methods recited in any of the embodiments. In some embodiments, a computer program product comprising a computer-readable program medium code stored thereupon, the code, when executed by a processor, causing the processor to implement any method recited in any of the embodiments. The above embodiments and other aspects and alternatives of their implementations are described in greater detail in the drawings, the descriptions, and the claims below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example wireless communication network. FIG. 2 shows an example wireless network node. FIG. 3 shows an example user equipment. FIG. 4 shows show various exemplary Random Access Channel (RACH) procedures. FIG. 5 shows an exemplary RACH procedure in which reception (RX) beam has a correspondence relationship with transmission (TX) beam. FIG. 6 shows an exemplary RACH procedure in which RX beam does not have a correspondence relationship with TX beam. FIG. 7 shows an exemplary RACH procedure with Msg1 repetitions using multiple beams. FIG. 8 shows an exemplary Media Access Control Protocol Data Unit (MAC PDU) structure. FIG. 9 shows an exemplary MAC PDU subheader. FIG. 10 shows an exemplary MAC Random Access Response (RAR) structure. FIG. 11 shows an extended MAC PDU subheader with optimal uplink beam indication according to embodiments of this disclosure. FIGs. 12-13 show exemplary structures for a new octet added to the MAC RAR. FIG. 14 shows an exemplary extended MAC RAR according to embodiments of this disclosure. FIG. 15 shows an exemplary RACH procedure in which different beams and beam level Msg1 repetition are employed. FIG. 16 shows an exemplary RO group set which includes one or more RO groups associated with a same SSB. FIGs. 17-18 show various example RO group sets. DETAILED DESCRIPTION Wireless Communication Network FIG. 1 shows an exemplary wireless communication network 100 that includes a core network 110 and a radio access network (RAN) 120. The core network 110 further includes at least one Mobility Management Entity (MME) 112 and/or at least one Access and Mobility Management Function (AMF) . Other functions that may be included in the core network 110 are not shown in FIG. 1. The RAN 120 further includ