Adapative arq schemes and their performance evaluation under full-duplex transmission

Adaptive ARQ (automatic repeat request) is an error-control scheme in data transmission in which the number of successively transmitted data blocks and the data block length are adjusted according to the bit error rate. This scheme performs better in half-duplex transmission than the conventional selective repeat (SR) and go-back-N (GBN) schemes when the bit error rate is either not known or varies with time. This paper proposes a control procedure for the full-duplex adaptive ARQ scheme. In this procedure an observation period is defined and the data block length is adjusted dynamically according to the success of the data block transmission in the observation period. The throughput of this scheme is analyzed. The proposed scheme is compared with nine conventional schemes, including SR and GBN, in terms of performance. The results indicate that the performance of the adaptive ARQ scheme is very close to that of the fixed data block scheme in which the optimal data block length is selected statically. It is also shown that the performance of the adaptive ARQ scheme does not degrade as rapidly as in other schemes when the bit error rate increases.