The users' performances are affected by the interferences in cellular systems. Especially for the users on the boundary whose communication qualities are poor. The interference alignment (IA) is a promising technology to effectively mitigate interferences and improve system throughput in wireless communications which has received lots of attentions. In this paper, we propose a linear IA algorithm that can achieve high degrees of freedom with less antennas for the users on the boundary of two-cell multiple-input multiple-output (MIMO) cellular systems. The algorithm uses the precoding vectors to eliminate the inter-user interference (IUI) and uses the interference suppression vectors to remove the inter-cell interference (ICI). Assuming each Base station equipped with M antennas communicate with K users each equipped with N antennas. Just let M=K and N=K+1 , the proposed algorithm can complete downlink and uplink IA and can achieve a total DOF of 2K with low overhead. The algorithm doesn' t require inter-cell feedback in the downlink and it requires only a small amount of inter-cell feedback in the uplink. Simulation results show that the proposed algorithm can achieve better performance than the conventional schemes.%在蜂窝系统中,由于干扰的存在,用户性能受到影响,特别是对于小区边缘用户,其通信质量较差.干扰对齐作为一种能够消除干扰、提高系统容量的技术,近年来受到广泛关注.针对多天线两小区蜂窝系统的边缘用户,本文给出了一种系统开销小、需要天线数少的线性干扰对齐算法.该算法利用发送端预编码矢量消除小区内干扰,利用接收端干扰抑制矢量消除小区间干扰.采用本文算法后,在每个小区有K个用户、基站有M根发送天线、用户有N根接收天线的情况下,只需M=K和N=K+1就可以实现上下行的干扰对齐,整个系统可以达到2K的自由度,并且在下行链路中不需要小区间反馈,而在上行链路中只需要较小的小区间反馈.仿真结果表明,本文提出的算法能够以较小的开销实现比以往的算法更好的性能.
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