Flexible adjacent channel interference and phase noise suppression in energy-efficient OFDMA receivers

This paper addresses the problem of phase noise mitigation in OFDMA-based radio link in a case where also adjacent channels are downconverted and therefore affected by the phase noise. The paper proposes the use of receiver-side digital-signal-processing algorithm for mitigation of receiver phase-noise in case of adjacent channel interference. The idea of the algorithm is to first detect the received signal, and then to construct an estimate of the phase-noise-free signal from the detected symbols and channel estimates. The phase noise is then estimated by comparing the received signal with phase noise to the phase-noise-free estimate. The algorithm can be used iteratively. Simulations are then done to show that the algorithm indeed is able to efficiently mitigate the phase noise effects even when adjacent channels are present. This algorithm allows moving the complexity from the analogue side to the digital side of the receiver and thus potentially results in very energy efficient receiver design.