The optimum switching thresholds that maximize the throughput are found.Theoretic analysis and numerical results indicate that VS-AM-SR-ARQ system can get good performance in fading channels.

• 理论分析和数值计算结果表明，可变包长可变调制方式的ARQ系统可以更好地适应衰落信道，其吞吐量性能要优于普通的ARQ系统。