k用户MIMO-Y双向中继信道中物理层网络编码研究

Physical-layer network coding in k-users MIMO-Y two-way relay channels

为了使k个用户能够在多输入多输出Y(multi-input multi-output-Y)双向中继信道中利用物理层网络编码技术实现用户间信息交换,在上行链路阶段和下行链路阶段均采用广义信号对齐(GSA,general signal alignment)技术,提出了GSA-GSA方案。本方案将对齐信号从传统的方向子空间转移到变换子空间,在源节点和中继节点联合设计预编码矩阵和处理矩阵,克服了传统信号空间对齐成立的条件限制。同时分析了该方案的收发天线数目约束条件以及系统和速率,通过仿真对比可以看到当信噪比和系统自由度(Do F,degrees of freedom)都相同时,该方案能减少系统所需天线数目,提高系统可达和速率。

In order to exchange information among k users using the technology of physical-layer network coding in the multiple input multiple output Y two-way relay channels, the GSA-GSA scheme was proposed, using the technology of general signal alignment during the uplink and the downlink. The signals were exchanged between every source node align in a transformed subspace, rather than the direct subspace. This was realized by jointly designing the precoding matrices at all source nodes and the processing matrix at the relay. The constraints of the number of sending and receiving antennas and the sum rate of proposed scheme were analyzed. In simulation, it can figure out that the proposed scheme needs fewer antennas in the whole system and can improve the achievable system sum rate under the same SNR and degrees of freedom.