基于欠采样的宽频段多窄带信号频谱盲恢复系统

Blind-spectrum reconstruction system of multi-narrowband signal in high-frequency section based on sub-sampling

针对基于调制宽带转换器的频谱盲恢复算法原理复杂且硬件实现较困难的问题,提出通过构造一个三路参差欠采样的频谱盲恢复系统来实现原始信号频谱的盲恢复。首先将宽频段内的多窄带信号经过功分器分成三路,然后分别进行不同采样率的欠采样,同时对三路欠采样信号进行傅里叶变换并拓展到感兴趣的频谱范围,最后通过综合处理就可实现频谱的盲恢复。该方法在工程上易于实现,可以同时实现低速采样速率与高精度估计,而且在较低信噪比的情况下仍可获得较高的估计精度。计算机仿真实验验证了该方法的有效性。

Aiming at the problem that spectrum reconstruction algorithm based on modulated wideband converter is complex and hard to be realized in real applications, a new method of blind-spectrum reconstruction of original signal based on three pathways sub-sampling system is proposed. First the power divider to make the multi-narrowband signals into three pathways is used, and then the three signals are sampled with different sampling rate respectively. After that, Fourier transformation is applied to these signals and they are all extended to a fixed length. Finally, blind spectrum reconstruction is realized by synthetic processing. This approach is easy to realize in real application and has the advantages of low sampling rate, high precision and easy implementation, even if in very low signal to noise ratio. The validity of the proposed algorithm is verified by simulations.