Abstract:

A new downlink spatial coordination scheme is proposed for orthogonal frequency division multiple access (OFDMA) 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 intersector interference, while maintain sector average throughput. The superiority is distinct even when imperfect CSIT is caused by limited codebook and increased feedback granularity. 

Key words: orthogonal frequency division multiple access, multiuser, minimum mean square error, interference coordination