Oversampled perfect reconstruction DFT modulated filter banks for multi-carrier transceiver systems

Abstract

In this work, we propose a novel method for the design of oversampled perfect reconstruction (PR) discrete Fourier transform (DFT) modulated filter banks (FB) for application to multi-carrier modulation (MCM). The PR property is enforced by employing a parametric class of paraunitary matrices to form the transmit/receive polyphase filters of the transceiver system. Specifically, the polyphase filters are formed by cascading special types of paraunitary matrices characterized by a limited set of design parameters. To reduce the number of these parameters, three different factorization methods are employed and compared. Through the optimization of these design parameters, the stop-band energy of the subband filters can be minimized which leads to improved spectral containment. The performance of the proposed system is investigated in a multi-carrier transceiver application, where it is compared with OFDM and other recently proposed FB structures. Numerical results show that the proposed scheme leads to a clear advantage not only in additive white Gaussian noise (AWGN) and frequency selective channels, but also in the presence of channel impairments such as narrow band interference or carrier frequency offset. In particular, it is found that a significant reduction in the bit error rate can be achieved by employing the proposed scheme.