High Performance Space Frequency Interleaved MIMO-OFDM Eigenmode Transmission Systems

Spatial multiplexing with linear preceding is a simple technique to increase system capacity and to exploit the high spectral efficiency provided by multiple-input multiple- output (MIMO) systems, and it can be easily implemented over frequency-selective MIMO channels by using orthogonal frequency division multiplexing (OFDM). The optimal transmitter preceding matrix is obtained by singular value decomposition (SVD) of the channel matrix. The eigenmodes of the channel matrix exhibited frequency selectivity, and the signal to noise ratio associated with each of the eigenmodes is directly proportional to its eigenvalue. Space frequency interleaver aims to achieve space and frequency diversity. Based on these observations, this paper proposes a weighted soft decision Viterbi decoding by using the eigenvalues of the channel matrix, to implement high performance space frequency interleaved MIMO-OFDM eigenmode transmission systems. Our simulation results confirm that this technique with low complexity improves error rate performance considerably.