基于无线电波广播特性的多用户自动请求重传

Multi-user automatic repeat request based on the broadcasting nature of radio waves

摘要: 提出了一种多用户自动请求重传的方法。采用网络编码基站将多个用户的重传数据包线性组合在一起后广播；用户利用置信传播算法从中检测出基站发给本用户的重传数据包，并和以前传输的数据包软合并后译码。分析表明：多用户自动请求重传能够将无线通信系统的频谱效率提高10%左右，并且复杂度和单用户自动请求重传相近。另外，该方法适用于所有类型的自动请求重传机制。

Abstract: Multi-user automatic repeat request(ARQ)is investigated.After separated channel coding at the base station,the packets sent to the users who request for retransmission are network coded and then broadcasted.At the intended users,the retransmission packets are detected from the composite packet by belief propagation(BP)algorithm and combined with the data received in previous transmission phases.Analysis shows that multi-user ARQ can improve the spectrum usage by about 10%.Meanwhile,this ARQ scheme keeps the complexity as low as single user ARQ and is applicable to all type of ARQ mechanisms.