SFICEE (spatial-frequency iterative channel estimation and equalization) in underwater acoustic MIMO-OFDM communication

In MIMO-OFDM underwater acoustic communication system, mutual channel interference and frequency domain deep selectivity due to serious time delay in underwater acoustic channel lead to severe communication performance. We present SFICEE method for space frequency block coding MIMO-OFDM communication system. In this receiver algorithm, channel of each transceiver pair is estimated through taking advantage of the space frequency orthogonal characteristics. Then spatial frequency equalization is introduced to obtain initial symbol estimation. The symbol estimation is iteratively fedback to update the channel estimation and forwarded to spatial frequency soft equalization. Simulation and analysis show that, the proposed method gains about 4.8 dB as compared with STBC system and 2.8dB as compared with SFBC system after two iterations. And also this method gets great output signal to noise ratio (R_SN) improvement, as can be seen from the convergence of constellation, and shows visible reduction in bit error ratio.