BPSK-OFDM signal detection in time-varying channels using prior information

The signals of BPSK-OFSM systems are real-valued, however, this property is ignored in state-of-the-art approaches, leading to detection performance degradation. In this paper, this prior knowledge is employed to develop a new equalizer based on minimum mean square error (MMSE) criterion. In particular, the proposed equalizer can achieve 3 dB gains comparing to the traditional MMSE equalizer in large signal-to-noise (SNR) region. Furthermore, the successive detection (SD) technique is used in the proposed equalizer is able to take the advantage of time diversity in time-varying channels. The computational complexity of the proposed methods are also analyzed and shown to be more efficient. Computer simulations are included to compare the proposed approaches with the traditional techniques in terms of detection performance.