Joint Source and Relay Precoding Designs for MIMO Two-Way Relaying Based on MSE Criterion
Joint Source and Relay Precoding Designs for MIMO Two-Way Relaying Based on MSE Criterion
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DOI：
10.1109/tsp.2011.2178598
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发表时间：
2011-12
影响因子：
5.4
通讯作者：
Rui Wang;M. Tao
中科院分区：
文献类型：
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作者：
Rui Wang;M. Tao
合理设计预编码器可以显著提高多输入多输出（MIMO）中继系统的频谱效率。本文研究了MIMO双向中继系统中基于均方误差（MSE）准则的联合源和中继预编码设计，其中两个多天线源节点通过多天线放大转发中继节点交换信息。这个问题是非凸的，它的最优解仍然没有解决。为了找到一种有效的解决方法，我们首先将原问题解耦为三个可处理的子问题，然后提出了一种基于交替优化的迭代预编码设计算法。每个子问题的解都是最优唯一的，从而保证了迭代算法的收敛性。其次，我们提出了一种结构化的预编码设计，以降低计算复杂度。提出的预编码结构能够并行化多址（MAC）阶段和广播（BC）阶段的信道。从而将预编码设计简化为一个简单的功率分配问题。最后，针对每个源节点只传输一个数据流的特殊情况，提出了一种基于源天线选择（SAS）的预编码设计算法。该算法只选择一个天线从每个源传输，因此需要较低的信号开销。通过全面的仿真来评估所有提出的预编码设计的有效性。
Properly designed precoders can significantly improve the spectral efficiency of multiple-input multiple-output (MIMO) relay systems. In this paper, we investigate joint source and relay precoding design based on the mean-square-error (MSE) criterion in MIMO two-way relay systems, where two multiantenna source nodes exchange information via a multiantenna amplify-and-forward relay node. This problem is non-convex and its optimal solution remains unsolved. Aiming to find an efficient way to solve the problem, we first decouple the primal problem into three tractable subproblems, and then propose an iterative precoding design algorithm based on alternating optimization. The solution to each subproblem is optimal and unique, thus the convergence of the iterative algorithm is guaranteed. Second, we propose a structured precoding design to lower the computational complexity. The proposed precoding structure is able to parallelize the channels in the multiple access (MAC) phase and broadcast (BC) phase. It thus reduces the precoding design to a simple power allocation problem. Last, for the special case where only a single data stream is transmitted from each source node, we present a source-antenna-selection (SAS)-based precoding design algorithm. This algorithm selects only one antenna for transmission from each source and thus requires lower signalling overhead. Comprehensive simulation is conducted to evaluate the effectiveness of all the proposed precoding designs.