Opportunism Transmit Mechanism Research in Cognitive Network

Under the condition of limited feedback, due to the multiple antennas cognitive two-way relay system due to the relay node have been the channel state information and the actual channel state information is error, caused the user system interference to primary user system increases, at the same time reduces the transmission rate of user system. Aiming at this problem, this paper on the basis of the statistical features of quantization error, put forward an algorithm to overcome the quantization error of beam forming. This algorithm under the condition of limited interference to primary user system, with the minimum mean square error (mse) is a standard, improved the user's transmission rate, the simulation results show that the proposed algorithm compared with other algorithm, effectively suppress the influence of quantization error, improve the transmission rate of user system, reduces the error rate of user system.