Filter bank based multiuser receiver for wireless OFDMA systems

One challenge associated with OFDMA is how to effectively separate signals of different users in mobile system. Another one is that MAI (multiple access interference) limits the performance of OFDMA system. In this paper, a novel filter bank based OFDMA system design is proposed to solve the above problems in subband allocation OFDMA system. In the scheme, OFDM modulation is employed in data-carrying subband for each user. The polyphase filter bank (PPFB) effectively decreases MAI and separates the overlapped multiuser's signal, which simplifies the multiuser receiver into a cluster of single-user receivers in a synchronous or asynchronous channel. The proposed scheme retains all the advantages of OFDM modulation and PPFB multiplexing. The signal processing model in frequency domain is given. Demodulation performance is investigated. Investigations show that the proposed multiuser receiver effectively separates distinct users and depresses MAI compared to subband OFDMA system; it is elegant, flexible, and robust to multipath delay spread of radio channel compare to filtered multitone transmission (FMT) system.