水声通信中一种有效的停等自动重传请求方案

针对水声信道,提出了一种改进的停等自动重传请求（stop-and-wait automatic repeat request，简称SWARQ）方案。为了提高传输的可靠性，分组中的每个比特连续传输Ⅳ次。对所提方案的理论上所得到的吞吐量关于信道的比特信噪比（SNR）、分组长度、每个比特连续传输的次数以及信道传输速率与信道传播时延之积进行了优化．较之于文献中所提及适合水声信道的基本SWARQ及其改进方案．所提出的ARQ方案能显著地提高水声通信系统的吞吐性能。而且．随着比特信噪比的增大，最优的N对分组长度、信道传输速率与信道传播时延之积的敏感度大大地降低。

An efficient stop-and-wait ARQ scheme over underwater acoustic channels

An improved stop-and-wait automatic repeat request （SW ARQ） scheme over underwater acou- stic channels is proposed. In the proposed ARQ scheme, each bit in a packet is repeated N times consecutively to increase transmission reliability. The throughput, theoretically derived for the proposed scheme, is optimized with respect to the bit signal to noise ratio （SNR）, the packet length, the number of copies transmitted consecutively per bit and the product of the channel transmission rate and propagation time. Compared to basic and modified versions of SW ARQ scheme described in the literatures, the proposed scheme can improve throughput performance of underwater acoustic communications systems markedly. Moreover, with an increase in SNR, the sensitivity of the optimum N to both the packet length and the product of the channel transmission rate and propagation time can greatly be reduced.