Generalized Eigenvector for Decentralized Transmit Beamforming in the MISO Interference Channel

This paper deals with the problem of sum-rate optimal transmit beamforming for the multiple-input-single-output (MISO) interference channel. Under realistic assumptions (i.e. the beamformers are able to decrease the interference power level below the desired signal one), we derive a decentralized beamformer that optimizes the sum-rate. This is of importance since it is known that obtaining the sum-rate optimal transmit beamformer is an NP-hard problem. The design is presented in closed-form and, thus, it is adequate for the future wireless high data rate spectrum-sharing networks due to its low complexity. We evaluate its performance both analytically and numerically. The results show that it behaves well in scenarios with practical level of interference and it outperforms the current decentralized designs when the channel link gains are asymmetric.