时间反演多址系统中的一种多用户检测算法

A Multiuser Interference Cancellation Algorithm in Time Reversal Division Multiple Access System

针对时间反演多址系统中信道的相关性会导致多用户干扰的问题,为了消除用户间干扰,降低计算复杂度,提出基于最小均方误差的3条对角线矩阵分解的低复杂度近似算法.首先提取检测矩阵(Gram-N)中包含主对角线的3条对角线矩阵;然后将3对角线矩阵分成2个2对角线矩阵;再利用2对角线矩阵求逆规律,分别求出这2个2对角线矩阵的逆,由此得出3对角线矩阵的逆;最后,根据诺依曼级数近似,用3对角线矩阵这个稀疏矩阵的逆来逼近Gram-N的逆.仿真结果表明,该算法在误码率和频谱效率方面具有明显的性能优势,并且具有较低的复杂度,在复杂度较低时可获得近乎最优的性能增益.

Aiming at solving the problem of multi-user interference caused by channel correlation in time reversal division multiple access system,eliminating inter-use interference and reducing computational complexity,a low complexity approximation algorithm of matrix decomposition of tridiagonal matrices based on minimum mean square error is proposed. Firstly,the tridiagonal matrix that include the main diagonal line in the detection matrix(Gram-N) is extracted,and the tridiagonal matrix into two double diagonal lines matrices is divided. Then,by using the inverse rule of double diagonal lines matrix,the inverse of these two double diagonal lines matrices is obtained,the inverse of the tridiagonal lines matrix is applied in the algorithm. Finally,according to the Neumann series approximation,the goal of approximating Gram-N’s inverse is realized by using the inverse of tridiagonal matrix. Simulations show that the proposed algorithm has obvious performance advantages in terms of bit error rate,spectral efficiency,and complexity. The algorithm can obtain a near-optimal performance gain when the complexity is low.