Downlink capacity evaluation of SA-MIMO system under single-user scenario

The smart antennas-MIMO (SA-MIMO) system combines MIMO and smart antennas by replacing each antenna of MIMO with a smart antenna array. For the general case, it is difficult to derive closed-form solutions of the optimal beamforming vectors to the capacity optimization problem of the SA-MIMO system. In this paper, the Particle Swarm Optimization (PSO) algorithm is presented for determining the suboptimal beam forming vectors. To reduce complexity, this paper gives the fitness function according to Tr(HH) of the H channel matrix H. Some numerical results show that the proposed method is viable.