MMSE-Interference Canceling Receiver for QAM-FBMC Systems

Abstract

Quadrature amplitude modulation-filter-bank multi-carrier (QAM-FBMC) technology, which utilizes a non-orthogonal pulse-shaping filter, has high spectral confinement characteristics and spectral efficiency, and it is considered as a candidate waveform to replace cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM). However, the QAM-FBMC system suffers from performance degradation due to the non-orthogonal filter no matter how well the prototype filter is designed. In this letter, we propose the interference-canceling algorithm for QAM-FBMC with an MMSE receive filter. The proposed algorithm effectively mitigates the performance degradation caused by the non-orthogonal filters of QAM-FBMC systems, and it closely achieves the performance of CP-OFDM system in moderate SNR region. Also, the proposed algorithm performs the symbol-wise detection, which allows practical implementation without system delay.