Resource allocation and transmission method of MsgA in two-step random access

Abstract

The invention discloses a resource allocation and transmission method of MsgA in two-step random access. The resource allocation and transmission method comprises the following steps: 1, uniformly grouping preambles under each RO at equal intervals; 2, time-frequency domain resources of one or more POs corresponding to the RO are divided according to time domains to form L PUSCH resource sets withcontinuous time domains, and each PUSCH resource set with continuous time domains comprises a plurality of PRUs; 3, after the UE selects to send a certain preamble on the RO, repeatedly sending the MsgA payload for L times on the PRU of the L PUSCH resource sets corresponding to the PO; 4, correspondingly mapping a group of preambles to a PRU of a PUSCH resource set when the MsgA payload is senteach time; and 5, when the MsgA payload is repeatedly sent, a different mapping relationship from preamble to PRU is adopted for each sending. According to the method provided by the invention, a many-to-one mapping method from RACH preamble to PUSCH resources is designed; according to the resource mapping method and the PUSCH payload repeated transmission scheme combined with the resource mappingmethod, the PUSCH resource utilization efficiency is improved, and the PUSCH receiving success probability is increased.

Description

technical field [0001] The invention belongs to the technical field of mobile communication, and in particular relates to a resource configuration and transmission method of MsgA in two-step random access. Background technique [0002] In 5G NR Release16, in order to reduce the system delay, a two-step random access was proposed at the 3GPPRAN#82 meeting. The two-step random access consists of two-step messages, that is, the MsgA sent by the UE and the MsgB fed back by the base station, such as figure 1 As shown, among them, MsgA is composed of two parts: PRACH preamble and payload carried by PUSCH, both of which are sent by TDM, such as figure 2 As shown, the PUSCH in MsgA is similar to Msg3 in the four-step access, which will carry specific UE identity information to facilitate the base station to identify the user identity. In addition, the size and content of the PUSCH vary depending on the RRC state. Different, the RAR message in MsgB and four-step access is similar t...

AI Technical Summary

Problems solved by technology

[0004] Since there is no pre-scheduling information for PUSCH in two-step random access, the mapping rules from PRACH preamble to PUSCH resources should be defined so that the base station can know the resource location and configuration information of PUSCH after detecting the preamble, reducing the complexity of PUSCH decoding. At the same time, it is beneficial to use a suitable beam for reception. From the perspective of mapping ratio, the conclusion reached by 3GPP has passed two mapping methods: one-to-one mapping and many-to-one mapping from preamble to PRU, such as image 3 As shown, when one-to-one mapping is used, multiple random access users using different preambles can be completely distinguished, but on the one hand, due to the existence of multiple PUSCH configurations, the available PUSCH resources are limited relative to the PRACH resources, so the available PUSCH Resources may not be sufficient to support one-to-one mapping; on the other hand, PUSCH resource utilization efficiency is not high during one-to-one mapping; when preamble to PRU is many-to-one mapping, there are PUSCH between multiple users using different preambles Resource conflicts lead to a decrease in the success rate of PUSCH decoding

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