关键词: 离散傅里叶变换, 调制滤波器组, 多载频系统, 原型滤波器, 样条函数, 正交频分复用调制系统

Abstract: In order to improve the poor frequency selectivity and spectral leakage of traditional Orthogonal Frequency Division Multiplexing (OFDM) multi-carrier transceiver, multi-carrier transceiver based on modified Discrete Fourier Transform (DFT) filter bank was introduced. The design problem of it was formulated as nonconstrained minimized optimization of perfect reconstruction error of modulated filter banks, and the modified window method was taken to design the prototype filter in the modulated filter banks and linear optimization was used to optimize the objective function. Compared to the traditional window method, a spline function was exploited in the transition band of ideal filter of the modified window to eliminate the Gibbs effect. The simulation results show that the designed filter bank with the proposed method gives a better performance in terms of stopband attenuation, and reconstruction error, and the resulted multicarrier transceiver a better Symbol Error Rate (SER) performance in Quadrature Phase Shift Keying (QPSK) modulation and the 3GPP TS 25.104 vehicular multipath and one-tap frequency-domain equalization.

Key words: Discrete Fourier Transform (DFT), modulated filter bank, multi-carrier transceiver, prototype filter, spline function, Orthogonal Frequency Division Multiplexing (OFDM) modulation system