基于GMD的卫星MIMO系统预编码技术

Precoding Technology for Satellite MIMO System Based on GMD

将全频率多波束卫星系统建模为MIMO系统,分析其信道特征,在此基础上进行预编码设计以提高系统容量。针对SLNR/SSLNR预编码算法BER性能损失大的问题,基于GMD矩阵分解对SSLNR算法进行改进,结合其信道特点减小预处理矩阵的维度,提出GMD-SSLNR算法。首先基于用户间距进行分组,每组分别对等效信道矩阵进行GMD运算,能有效降低码流间的增益差,并采用THP方法在发端抵消掉已知的组间干扰泄漏。分析和仿真表明,相比SLNR-THP及SSLNR-THP算法,算法有效提高了系统的误码性能,并降低了运算复杂度。

Multi-beam satellite with full frequency multiplexing is modeled to MIMO system,and then its channel character is analyzed,based on which the precoding algorithm is designed to improve the system throughput.The existing SLNR/SSLNR precoding algorithms are all with loss of BER.In this paper,the SSLNR algorithm is improved based on GMD matrix decomposition,and the dimension of the preprocessing matrix is decreased because of the channel character and a new precoding algorithm named GMD-SSLNR is proposed The users are grouped based on the distance between them and each group decomposes the equivalent channel matrix respectively,which can reduce the gain difference among the data streams,and the known leaking interference of the transmitter is offset with the THP algorithm.Analysis and Simulation results show that compared to SLNR-THP and SSLNR-THP,the proposed algorithm can improve the BER performance and reduce the complexity.