双向中继系统用户联合预编码与检测算法研究

摘要

Two-way relay cooperative communication system demonstrates significant gain in spectral efficiency when two user nodes exchange information via a relay node. For improving the Bit Error Rate (BER) performance, a joint precoding and detection algorithm is proposed based on Lattice Reduction (LR) when all the nodes equipped with multiple antennas. The proposed algorithm modifies the channel gain matrix into more orthogonal matrix by the complex lattice reduction. Precoding and detection algorithms are combined to apply the modified matrix. The relay node processes the receiving signal by simple modulo operation and amplification. The main complexity of the algorithm is in the two user nodes. The simulation evaluations show that, the computational complexity of the algorithm is increasing just because the channel gain matrix is modified by lattice reduction. The proposed joint precoding and detection algorithm can significantly improve the performance of BER and achieve full diversity, hence it is applicable to engineering.%双向中继协同通信系统的两用户节点通过中继节点相互交换信息，显示了其在频谱效率上的优势。在系统装备多天线的情况下，为进一步改善误比特率性能，论文提出一种基于格规约算法的用户联合预编码与检测算法。该算法通过一次复数域格规约处理来提高信道增益矩阵的正交性，预编码和检测算法联合应用处理后的矩阵，中继节点仅需要对接收信号进行求模运算和放大转发，算法的复杂度主要集中在两用户节点上。仿真结果显示：相比于传统的预编码和检测算法，用户联合预编码与检测算法在计算复杂度仅增加了对信道增益矩阵一次格规约计算的前提下，可显著降低系统的误比特率，提高分集增益，具有工程实用价值。