针对多用户正交频分多址系统,提出了一种改进的下行空域干扰协调方案,该方案利用最小均方误差预编码来消除扇区间的同频干扰,改善边缘用户性能,并将最大化信号强度与最小化干扰泄露这2个目标函数分离到不同的资源上进行优化,简化了发射预编码矩阵的设计.系统级仿真结果表明,在发射端获得完整信道状态信息时,空域干扰协调方案可以减轻扇区间干扰,而并不引入扇区总吞吐量的损失.在码本大小、反馈粒度引起的信道状态信息不完全时,所提方案仍具有很好的性能增益.
A new downlink spatial coordination scheme is proposed for orthogonal frequency division multiple access (0FDMA) systems to mitigate inter-sector interference, in which the minimum mean square error (MMSE) precoding is utilized to improve the performance of edge users at neighbor sector. The design of precoding matrix is simplified by separating the objective functions that maximizes expected signal power and minimizes interference leakage in different resource groups. System level simulation demonstrates that the proposed scheme can significantly alleviate intersector interference, while maintain sector average throughput. The superiority is distinct even when imperfect CSIT is caused by limited codebook and increased feedback granularity.