基于非理想信道感知的认知MIMO-OFDM系统的最优功率分配

his paper is concerned with the optimal power allocation strategy in cognitive radio systems for a cognitive radio (CR) link under spectrum sharing with an existing primary radio (PR) link. The PR is equipped with multi antennas and the CR is in orthogonal frequency division multiplexing (OFDM) based multiple input multiple output (MIMO) cognitive radio systems. It is assumed that in channel learning scheme, CR transmitter first listens to PR transmission and then estimates the spaces that are orthogonal to the channels from PR. Unlike prior study on channel learning in MIMO based cognitive radio systems, this paper is first to bring the OFDM technology to MIMO based cognitive radio systems and consider the imperfect channel learning. Owning to the channel estimation errors, the interference from CR transmitter to PR terminals cannot be canceled completely. Moreover, an effective algorithm is proposed, and we get the optimal power allocation to maximize CR throughput in precondition of assuring PR QoS. Simulation results show the relations among the CR transmit power constraint, the interference power constraint at PR and CR throughput.