随着载人航天技术的发展，越来越多的航天任务需要利用卫星通信进行信息传输。已有的研究成果大都采用了ARQ机制来降低卫星信道的数据丢失率。然而由于卫星信道还具有长时延的特点，因此ARQ所采用的反馈机制会大幅增加卫星信道的传输时延。为了克服卫星信道中反馈机制带来的大时延问题，提出了一种虚拟ARQ（Virtual ARQ，VARQ）机制。在VARQ中，发送端并不依靠接收端的反馈信息来进行分组重发，而只根据当时估计的丢包概率来决定传输策略，从而可以大幅降低卫星信道的传输时延。随后，还对VARQ所具有的一些时延性质进行了理论证明。仿真结果显示，相对于选择性重传ARQ机制，VARQ机制能够降低大约25.69％的时延。%With the development of manned space technology , more and more space flight missions require information transmission via satellite communication .The existing research results mainly use ARQ mechanism to decrease the data loss probability of satellite channel .However , the acknowledg-ment mechanism of ARQ will highly increase the transmission delay of satellite channel .Therefore , a Virtual ARQ ( VARQ) mechanism was proposed in this paper to decrease the transmission delay of satellite channel due to acknowledgment mechanism .In VARQ, the sender does not use the ac-knowledgment messages , and only use the estimated packet loss probability to decide the transmis-sion policy .VARQ can highly decrease the transmission delay of satellite channel .In additon , the theoretical analysis of VARQ was also given .The simulation results showed that the VARQ mecha-nism could decrease the transmission delay by about 25 .69%as compared with the selective repeat ARQ.
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