多相随机子采样FFT模拟信息转换器

Implementation for Analog-to-information Convertor via Multiphase Random Sampling and Sub-sampled FFT

模拟信息转换器是实现稀疏信号压缩感知的一种装置,常用的主要结构是随机解调下采样,但是通常存在采样恢复精度低以及压缩率不高的问题。为提高压缩率及采样恢复精度,本文提出了一种多相随机子采样FFT模拟信息转换器实现方法,该模拟信息转换器由多相分频移相器、伪随机数发生器、多路并行低速ADC以及累加器组成。该方法利用信号在频域循环卷积后下采样等效于信号随机子采样FFT的特点,实现对信号的压缩采样,能有效提高信号压缩率及采样恢复精度,且结构简单、易于实现。仿真实验验证了此方法的有效性。

Analog-to-information convertor（ AIC） is a device which converts a sparse analog signal to compressed information. Down-sampled random demodulator is a major structure of AIC,which,however,exits the problems of low sampling recovery precision and low compression ratio. In order to improve compressed ratio and sampling recovery precision,an implementation for AIC via multiphase random sampling and sub-sampled FFT is proposed. It consists of multi-phase frequency divider,pseudo random number generator,analog-to-digital converter（ ADC） and accumulator. This AIC uses the property that down sampling after circular convolution in frequency domain is equivalent to multiphase random sampling in time domain and then applying sub-sampled FFT,making it an effective way of signal compressing sampling. The structure of this AIC is simple and easy to implement. Experiment results show the effectiveness of the proposed method.