All phase-FFT signal detection method for QAM system in fast-moving wireless channel

In this paper, we investigate an efficient quadrature amplitude modulation (QAM) signal detection method in fast-moving multipath wireless channel using all phase fast-Fourier transform (ap-FFT) algorithm. As the amplitude spectrum of signal with the proposed detection algorithm is the square of that of fast-Fourier transform (FFT) and the phase isn´t influenced by frequency shift between the transmitter and receiver oscillators that it can significantly correct the fuzzy constellation caused by frequency offset, restrain the additive white Gaussian noise (AWGN) to some extent at high Signal-to-Noise Ratio (SNR). The system performance in terms of Symbol Error Ratio (SER) is improved with little additional computation.