Towards Optimal Schemes for the Half-Duplex Two-Way Relay Channel
Towards Optimal Schemes for the Half-Duplex Two-Way Relay Channel
复制标题
半双工双向中继通道的优化方案
DOI：
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发表时间：
2011
期刊：
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通讯作者：
M. Stein
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文献类型：
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作者：
M. Stein
研究了小型全连通网络中的受限双向通信问题。该网络由三个节点组成，所有节点都可以访问具有半双工约束的公共信道。两个节点想要建立对话，而第三个节点可以协助双向传输过程。所有节点都事先同意传输协议，并且问题限于不允许对话编码器通过使用先前的接收信号来建立协作。该信道被称为受限半双工双向中继信道。在这里的信道的定义和可实现的速率的外界是由应用割集定理。这表明问题由六个部分组成。我们提出了一个传输协议，它考虑到所有可能的传输-接收配置的网络，并执行部分解码的消息在中继以及顺序解码的对话节点。通过使用随机码和次优译码器，得到了可达速率的两个内界。限制到建议的策略和固定的输入分布，它被认为是可能的，以确定最佳的传输方案相对于各种合理的目标，在低复杂性。与没有中继的双向通信相比，AWGN信道模型的仿真结果表明，可以同时提高两个对话消息的通信速率，并优于忽略可用直接路径的中继策略。
A restricted two-way communication problem in a small fully-connected network is investigated. The network consists of three nodes, all having access to a common channel with half-duplex constraint. Two nodes want to establish a dialog while the third node can assist in the bi-directional transmission process. All nodes have agreed on a transmission protocol a priori and the problem is restricted to the dialog encoders not being allowed to establish a cooperation by the use of previous receive signals. The channel is referred to as the restricted half-duplex two-way relay channel. Here the channel is defined and an outer bound on the achievable rates is derived by the application of the cut-set theorem. This shows that the problem consists of six parts. We propose a transmission protocol which takes into account all possible transmit-receive configurations of the network and performs partial decoding of the messages at the relay as well as sequential decoding at the dialog nodes. By the use of random codes and suboptimal decoders, two inner bound on the achievable rates are derived. Restricting to the suggested strategies and fixed input distributions it is argued to be possible to determine optimal transmission schemes with respect to various reasonable objectives at low complexity. In comparison to two-way communication without relay, simulations for an AWGN channel model then show that it is possible to simultaneously increase the communication rates of both dialog messages and to outperform relaying strategies that ignore an available direct path.