三小区环境中基于三角分解的低复杂度干扰对齐算法

摘要

This paper considers MIMO cellular downlink model with 3 cells and 2 edge users in each cell. By mean of orthogonal-triangular decomposes of the joint channel matrix, the equivalent system model is derived, which has the same degrees of freedom with the original model. Based on the new model, the paper proposes a linear interference alignment algorithm to align and eliminate inter-cell and intra-cell interference according to different interferences from different cells. Before the signals have not received by the users, the proposed algorithm takes advantages of the channel decomposition to eliminate half of inter-cell interference, so as to reduce the number of the receiving matrix and simplify the complexity in receivers. The simulation results show that for given the antenna configuration, system capacity and energy efficiency have significantly improved with the increase in the data stream. In the case of the same degree of freedom, the number of antennas has a greater impact on system capacity and energy efficiency.%　　针对3小区每小区2个边缘用户的MIMO下行链路，在不改变系统自由度的前提下对联合信道进行下三角分解得到系统的等效模型；在此基础上，根据不同小区受到的干扰不同，该文提出一种线性干扰对齐算法同时消除小区间干扰和小区内干扰。该算法利用联合信道分解可以先消除一半的小区间干扰，并根据不同小区的用户设计其干扰抑制矩阵，减少了用户端接收矩阵个数及相应处理，从而降低了接收端的复杂度。仿真表明，随着数据流的增加，系统容量和能量效率都有明显的提高，在自由度相同的情况下，天线数不同对系统容量和能量效率有较大影响。