A precoding method for closed-loop MIMO-OFDM systems
This paper presents a precoding method for closed loop MIMO-OFDM systems. For precoding, the codeword is selected by comparing the unitary channel matrix, obtained from the SVD method, with a predefined codebook. The performance of closed and open-loop MIMO-OFDM systems is investigated for the case of perfect and imperfect CSI, as well as for different level of quantization. The simulation results show that the first one outperforms the later one in all case. The system performance gain depends on the number of bits using for feedback channel.