MIMO干扰信道下低复杂度的分布式干扰对齐算法

Low Complexity Distributed Interference Alignment for MIMO Interference Channel

干扰对齐技术可以有效地提高干扰信道容量和抑制干扰,其问题归结为求得闭式解。传统的干扰对齐方案根据信道的互易性,采用迭代的方法(分布式)来逼近闭式解,但带来了较大的计算开销。本文在K用户MIMO干扰信道系统中提出一种低复杂度的分布式干扰对齐算法,通过对用户K的干扰协方差矩阵进行排序QR分解算法,该分解算法是基于修正的Gram-Schmidt方法,选出酉矩阵Q最后的dk列作为用户近似的干扰抑制滤波矩阵,和传统分布式干扰对齐方案相比,在基本保持系统容量和迭代收敛速度的同时,系统的复杂度明显降低。仿真结果验证了算法的有效性。

Interference alignment technique effectively improves the channel capacity and restrain the interference, whose question can be attributed to find a closed-form solution. According to the reciprocity of the channel, the traditional interfer- ence alignment scheme uses iteration method（distributed） to approximate the closed-form solution, but it bring tremendous computational overhead. In this letter, a low complexity distributed interference alignment is proposed for K user MIMO in- terference channel. By means of QR decomposition of the interference covariance matrix of the Kth user based on modified Gram-Schmidt, we will choose the last dk columns of the unitary matrix Q to approximate as the interference suppression fil- ter matrix of the user K. Compared to the traditional distributed interference alignment scheme, it not only is the same basi- cally in the system capacity and iterative convergence speed, but also obviously decreases the system computational com- plexity. The results of simulation show that the validity of the method,