Date Added: May 2012
When perfect Channel State Information (CSI) is available at each transmitter in K-user Multiple-Input Multiple-Output (MIMO) interference channels, it was shown that Interference Alignment (IA) achieves a full spatial multiplexing gain. However, a significant performance loss is inevitable in the IA when the CSI is fed back from receivers using the limited number of feedback bits. In this paper, the authors propose a new channel quantization strategy to optimize the performance of the IA with limited feedback. In their proposed scheme, they introduce an additional receive filter to minimize the chordal distance which accounts for the quantization error on Grassmann manifold.