低复杂度的多用户MIMO下行链路块对角化算法

Low Complexity Block Diagonalization Algorithm for Multiuser MIMO Downlink Systems

提出了一种低复杂度的多用户多输入多输出(MIMO)下行链路块对角化预编码算法,证明了该算法能够实现与传统块对角化算法完全相同的系统总容量。算法基于迫零方法进行改造,通过对迫零向量实施格拉姆-施密特正交,可以快速实现等效下行链路的全局块对角化,从而获得最终的预编码矩阵。由于算法避免了传统块对角化算法求解零空间所进行的矩阵奇异值分解运算,其计算复杂度相比传统方法有显著下降,下降幅度接近50%。

A low complexity block diagonalization precoding algorithm is proposed for multiuser multiple-input multiple-output （MIMO） downlink systems. It is proved that the algorithm can achieve the same sum capacity with that of the traditional block diagonalization one. The algorithm improves the existing zero forcing method. By performing Gram-Schmidt orthogonalization to zero forcing beams, the algorithm can achieve fast global block diagonalization of the equivalent downlink channel, thus further obtaining the precoders. Avoiding matrix singular value decomposition required when calculating null space in the traditional block diagonalization algorithm, the computational complexity of the proposed algorithm is greatly reduced by about 50%.