大多数干扰对齐算法都假定发送端可以获得理想的信道状态信息(CSI),由于信道估计误差、反馈延迟等原因,实际通信系统中CSI往往是有误差的。为此,该文提出一种基于QR分解的稳健干扰对齐算法。对含有误差的联合接收信号进行基于QR分解的预处理,消除一半有误差的干扰;然后在有误差的等效信道联合矩阵下,充分考虑信道误差和干扰的影响,通过最小化发送端泄漏到非目标接收端的干扰信号功率来设计预编码矩阵,并基于最小均方误差(MMSE)准则来设计干扰抑制矩阵。最后,在理想CSI和误差CSI的情况下,通过实验仿真,证明了该算法有效地提高了系统性能。
Most interference alignment algorithms assume that the senders know perfect Channel State Information (CSI), but in practical communication systems, due to the channel estimation error, the delayed feedback and so on the CSI often exists the error. Therefore, a robust interference alignment algorithm is presented based on the QR decomposition. Firstly, the QR is used to preprocess the jointly received signal with the of error for eliminating half of the interference terms. Then this paper minimizes the interference power from the sender to the other receivers to design the pre-coding matrix, and utilizes Minimum Mean Square Error (MMSE) criterion to design the interference suppression matrix. Finally, under the conditions of perfect CSI and error CSI, the simulation results verify that the proposed algorithm improves effectively the performance of the system.