载人航天
載人航天
재인항천
MANNED SPACEFLIGHT
2015年
2期
130-134
,共5页
卫星通信%长时延%ARQ%VARQ
衛星通信%長時延%ARQ%VARQ
위성통신%장시연%ARQ%VARQ
satellite communication%long delay%ARQ%VARQ
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。
隨著載人航天技術的髮展,越來越多的航天任務需要利用衛星通信進行信息傳輸。已有的研究成果大都採用瞭ARQ機製來降低衛星信道的數據丟失率。然而由于衛星信道還具有長時延的特點,因此ARQ所採用的反饋機製會大幅增加衛星信道的傳輸時延。為瞭剋服衛星信道中反饋機製帶來的大時延問題,提齣瞭一種虛擬ARQ(Virtual ARQ,VARQ)機製。在VARQ中,髮送耑併不依靠接收耑的反饋信息來進行分組重髮,而隻根據噹時估計的丟包概率來決定傳輸策略,從而可以大幅降低衛星信道的傳輸時延。隨後,還對VARQ所具有的一些時延性質進行瞭理論證明。倣真結果顯示,相對于選擇性重傳ARQ機製,VARQ機製能夠降低大約25.69%的時延。
수착재인항천기술적발전,월래월다적항천임무수요이용위성통신진행신식전수。이유적연구성과대도채용료ARQ궤제래강저위성신도적수거주실솔。연이유우위성신도환구유장시연적특점,인차ARQ소채용적반궤궤제회대폭증가위성신도적전수시연。위료극복위성신도중반궤궤제대래적대시연문제,제출료일충허의ARQ(Virtual ARQ,VARQ)궤제。재VARQ중,발송단병불의고접수단적반궤신식래진행분조중발,이지근거당시고계적주포개솔래결정전수책략,종이가이대폭강저위성신도적전수시연。수후,환대VARQ소구유적일사시연성질진행료이론증명。방진결과현시,상대우선택성중전ARQ궤제,VARQ궤제능구강저대약25.69%적시연。
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.