High SNR performance of antenna selection in MISO interference channel with zero-forcing and limited feedback

In the two-user MISO interference channel using transmit zero-forcing (ZF) strategy, if transmit antenna selection based on direct link channel gain is applied to select no less than two transmit antennas, we find that under limited feedback using more transmit antennas will actually induce more interference to the other users. In the high SNR region, the upper bounds of the throughput and the relative rate loss to the perfect channel state information (CSI) case are obtained. It is interesting to note that using a small number of transmit antennas can improve the performance considerably compared with that of using all the available antennas, even though some of the feedback bits are used to indicate the selected antennas. Numerical results also show that using selection can enjoy gains in throughput in the more than two users cases.