Physical-layer network coding with limited feedback in two-way relay channels
Physical-layer network coding with limited feedback in two-way relay channels
复制标题
双向中继通道中反馈有限的物理层网络编码
作者：
S. Sahin;Ümit Aygölü
在这项研究中，作者将有限反馈技术引入到物理层网络编码中，这是双向中继信道中频谱效率最高的协议，由一个中继和两个端（源）节点组成。在放大转发策略中，每个源节点通过中继提供的有限数量的反馈比特从训练序列中获取中继与自身之间的信道的完整信道状态信息(CSI)以及中继与其他节点之间的信道的部分CSI。在解码转发策略中，作者完全删除了训练序列，源节点从有限的反馈比特中提供中继和自身之间链路的部分CSI，其他链路的CSI对于该策略来说是无用的。针对两种策略的二进制相移键控 (PSK) 和正交 PSK 调制，得出了比特错误概率的严格上限，具体取决于反馈比特数。通过计算机模拟表明，两种策略均通过使用少量反馈比特来实现所有节点上具有完整 CSI 的系统的误码率性能。此外，所提出的所有节点均使用单个天线的方案降低了计算复杂度。
In this study, the authors introduce the limited feedback technique into the physical-layer network coding which is the most spectrally efficient protocol for two-way relay channels, consisting of one relay and two end (source) nodes. In amplify-and-forward strategy, each source node obtains full channel state information (CSI) of the channel between relay and itself from training sequences and partial CSI of the channel between relay and the other node by means of a limited number of feedback bits provided by the relay. In the decode-and-forward strategy, the authors completely remove training sequences and the source nodes provide the partial CSI of the link between relay and themselves from limited feedback bits, the CSI of the other link being useless for this strategy. Tight upper bounds on the bit error probability depending on the number of feedback bits are derived for binary phase shift keying (PSK) and quadrature-PSK modulations for both strategies. It is shown via computer simulations that the bit-error-rate performance of the system with full CSI at all nodes is achieved for both strategies by using a few number of feedback bits. Moreover, the computation complexity is reduced for the proposed scheme with a single antenna at all nodes.