Performance enhancement for co-channel interference cancellation with smart antenna and power adaptive in cooperative communication

Co-channel interference cancellation method are investigated for cooperative communication employing a decode-and-forward protocol when the base station is disturbed by the co-channel interference (CCI). In order to solve such interference problem, the beamforming method with the appropriate weight estimation for a smart antenna at the base station will be employed. We can also control the transmitted power at the interfering source, and maintain nearly a full diversity gain compared with the existing decode-and-forward cooperative communication. The network performance can be enhanced by the proposed power adaptive at the interference source by the quality of channel criterion and signal combining method. The maximum ratio combining (MRC) and the cooperative maximum ration combining (C-MRC) are used to combine the received signals arrived at the base station to achieve the minimum probability of error based on the experimental results from simulations. The results show proposed method in C-MRC systems had the lower probability of error than MRC because the effect of three gain factors: the antenna array gain obtained from the beamforming algorithm, the power gain of the proposed power adaptive strategy, and the diversity gain obtained from a signal combining of received signals from the relay.