关键词: 改进离散傅里叶变换波器组, 频谱感知, 认知无线电, 正交频分复用

Abstract: When used for cognitive radios, the traditional Orthogonal Frequency Division Multiplexing（OFDM） technology with its drawback of the spectral leakage will not only cause interference between neighboring zone but also reduce the primary user signal detection performance. This paper proposes a multi-band spectral detection scheme based on Modified Discrete Fourier Transform（MDFT） modulated filter bank. The detection probability expression of the cognitive radio system under MDFT modulated filter bank structure is derived. Theoretical analysis and simulation results show that the CR system based on MDFT filter bank has higher stop-band attenuation than the system based on OFDM with using rectangular window function as prototype filter. And with the pedestrian channel of 3GPP TS 25.104 protocol standards, especially at lower SNR, the spectrum sensing performance of the CR system based on MDFT filter bank structure is significantly improved compared to the system based on OFDM.

Key words: modified discrete Fourier transform filter bank, spectrum sensing, cognitive radio, orthogonal frequency division multiplexing