Novel Receiver Architecture for the Detection of QAM Signals in the Presence of Residual Phase Error and Channel Fading

In this paper, we present a new receiver architecture, which is motivated by optimum detection of quadrature amplitude modulation (QAM) signals in the presence of Tikhonov-distributed residual phase error due to the phase-locked loop (PLL)-aided phase tracking scheme. Performances on AWGN and fading channels are established in terms of bit error rate. The performances of the proposed architecture for 8- and 16-QAM constellations are assessed via simulation and are shown to follow those of the optimum receiver over a wide range of signal-to-noise ratio (SNR), while outperforming a standard coherent receiver operating in the presence of residual phase error by more than 2 dB.