A maximal ratio combining frequency diversity ARQ scheme for OFDM signals

Abstract

This paper proposes a maximal ratio combining (MRC) frequency diversity automatic-repeat-request (ARQ) scheme which is suitable for high data rate orthogonal frequency division multiplexing (OFDM) signals. The proposed scheme regularly changes the subcarrier assignment pattern at every retransmission. This scheme sharply reduces the number of ARQ retransmissions in slow fading environments by virtue of the frequency diversity effect. Computer simulation results show that the proposed scheme reduces the number of retransmissions to about 3 at the accumulative correct packet reception rate (ACPRR) of 0.99 while the conventional schemes lead to more than 10.