OPTIMAL POWER BACKOFF-BASED NON-ORTHOGONAL RANDOM ACCESS METHOD IN LARGE-SCALE M2M NETWORK

摘要

Disclosed is an optimal power backoff-based non-orthogonal random access method in a large-scale M2M network, comprising the following steps: 1) a base station increases an ACB factor by the times of an optimal number MTCD I ^* and sends the increased ACB factor to all MTCDs, and the MTCD that passes the ACB test sends a first message Msg1 to the base station by means of a physical random access channel, determines the number of MTCDs that select the same PA, i.e., the number of MTCDs that initiate random access attempts in a current access slot; 2) the base station sends a second message Msg2 to the MTCDs according to all selected PAs, and the MTCDs monitor an RAR represented by an RA-RNTI on a physical downlink control channel PUSCH; 3) the MTCD capable of monitoring the RAR transmits a third message Msg3 according to the selected tag PA, and the MTCDs of the same PA achieves NOMA on the same Physical Uplink Shared Channel (PUSCH) by means of the multiplexing of a power domain; 4) the base station uses an SIC to decode a data packet on the PUSCH, and sends a fourth message Msg4 to the successfully decoded MTCD. According to the method, the system throughput can be effectively improved and an access delay of a device is reduced.