EFFICIENT HYBRID ARQ PROTOCOLS WITH ADAPTIVE FORWARD ERROR-CORRECTION

In this paper, efficient Stop-and-Wait, Go-Back-N and Selective-Repeat hybrid ARQ protocols with Adaptive Forward Error Correction (AFEC) us ing convolutional coding are proposed and analyzed. The basic idea is to vary the coding rate for error correction according to system param eters, such as the signal-to-noise ratio, the round trip delay and the buffer size at the receiver, so as to maximize the throughput efficie ncy. The performances of the proposed ARQ protocols are evaluated for two channel models: a non-fading and an ideally-interleaved Rayleigh-f ading additive white Gaussian noise channel. In all cases it is found that the hybrid ARQ protocols with AFEC yield a comparatively high thr oughput under all channel conditions.