在3GPP TS 38.213 8.3中有这么一段话
“A UE transmits a transport block in a PUSCH scheduled by a RAR UL grant in a corresponding RAR message using
redundancy version number 0. For Msg3 PUSCH retransmissions, if any, of the transport block are scheduled by a DCI
format 0_0 with CRC scrambled by a TC-RNTI provided in the corresponding RAR message [11, TS 38.321]. The UE
always transmits the PUSCH scheduled by a RAR UL grant without repetitions.”
我的理解是Msg3的初始传输时,用于传输Msg3的PUSCH是有RAR UL grant来调度的。当Msg3重传时,PUSCH是有DCI 0_0来调度的。