OFDM mobile packet transmission system with multiuser detection and metric combining ARQ

This paper proposes an OFDM mobile packet transmission scheme that employs both non-linear multiuser detection (MUD) and automatic repeat request (ARQ) with metric combining for improving throughput performance. The scheme identifies users by detecting user identification (ID) symbols located at the head of a packet, and can separate the packets by MUD when the packets collide. Furthermore, it forces the respective transmitters to retransmit the same packets so as to reproduce the collision if the cyclic redundancy check (CRC) detects some errors, and employs metric combining for decreasing the number of retransmissions. In order to verify the throughput performance, computer simulations are conducted. The simulation results show that the proposed scheme can achieve much greater throughput than the conventional ones.