A Maximal Ratio Combining Frequency Diversity ARQ Scheme for High-Speed OFDM Systems

摘要

This paper proposes a new maximal ratio combining (MRC) frequency diversity automatic-repeat-request (ARQ) scheme suitable for high-speed orthogonal frequency division multiplexing (OFDM) systems that is based on the conventional packet combining ARQ scheme. The proposed scheme regularly changes the previously prepared subcarrier assignment pattern at each retransmission according to the number of retransmissions. This scheme sharply reduces the number of ARQ retransmissions and much improves the throughput performance in slow fading environments by virtue of the frequency diversity effect while it requires no complex adaptive operations. Computer simulation results show that the proposed scheme reduces the required number of retransmissions to about 3 at the accumulative correct packet reception rate (ACPRR) of 0.9.