Design and Simulation of Cosine Modulated Filter Bank Transmultiplexer with Canonic Signed Digit Coefficient Lowpass Filters

摘要

Cosine modulated filter bank transmultiplexer (CMFB TMUX) can be used for the efficient implementation of multicarrier communication system. If the coefficients of lowpass filters are represented in canonic signed digit (CSD) format, the hardware complexity of CMFB TMUX can be reduced. In this paper, the design and simulation of CMFB TMUX with CSD coefficient lowpass filters is presented. For this, CMFB TMUX with continuous coefficient transmitting and receiving lowpass filters is designed and Genetic algorithm (GA) is used for the coefficient synthesis of the lowpass filters in CSD format. A new chromosome encoding scheme is used for preserving the canonic property of the filter coefficients under genetic operations. Simulation results show that the CMFB TMUX obtained using the proposed algorithm has better signal to interference ratio (SIR) and frequency response than those obtained by rounding the continuous coefficients of lowpass filters to the nearest CSD number.