Centre TecnolÃ²gic de Telecomunicacions de Catalunya (CTTC)
This paper deals with the problem of sum-rate optimal transmit beam-forming for the multiple-input-single-output interference channel. Under realistic assumptions (i.e. the beam-formers are able to decrease the interference power level below the desired signal; the authors derive a decentralized beam-former that optimizes the sum-rate. This is of importance since it is known that obtaining the sum-rate optimal transmit beam-former is a 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. They 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.