Low Complexity data transmission over wireless system

It is proposed low-complexity block turbo equalizers for orthogonal frequency-division multiplexing (OFDM) system in a channel. The presented work is based on a soft minimum mean –square error (MMSE) block linear equalizer (BLE) that exploits the banded structure of the frequency –domain channel matrix, as well as a receiver window that enforces this banded structure. This equalization approach allows us to implement the proposed designs with a complexity that is only linear in the number of subcarriers. The turbo equalizer based on biased MMSE criterion is used simulation results show that the proposed iterative MMSE BLE achieves a better bit error rate (BER) performance. The proposed equalization algorithms are also tested in the presence of channel estimation errors. Comparison of equalization scheme has been analyzed.