预调制多陪集采样系统  

Pre-modulated multi-coset sampling system

作　　者：黄振[1] 柏正尧[1] Huang Zhen;Bai Zhengyao(School of Information Science and Engineering,Yunnan University,Kunming 650500,China)

机构地区：[1]云南大学信息学院,云南昆明650500

出　　处：《电子技术应用》2022年第4期48-52,共5页Application of Electronic Technique

基　　金：国家自然科学基金委员会-中国科学院天文联合基金(U1231122)。

摘　　要：目前,压缩采样系统主要有随机解调器、调制宽带转换器和多陪集采样3种,其中,多陪集采样的系统框架简单、重构成功率高,但用硬件实现时面临两个难题,一是低速模数转换器(ADC)的输入模拟带宽存在上限,二是难以实现各通道上的精准时延。借鉴调制宽带转换器在采样前先对输入信号进行预调制的思想,将预调制与多陪集采样结合,提出了预调制多陪集采样系统。采样前,在采样系统各通道上,由随机序列发生器产生周期单脉冲序列,对输入信号进行频谱调制以降低采样前信号的模拟带宽;然后,调制信号由低速ADC进行采样,且各通道上的低速ADC与随机序列发生器列共用同一个控制时钟;最后,采用多信号分类算法(MUSIC)算法近乎无失真地重构出输入信号。仿真实验结果表明,当以15%的奈奎斯特采样速率对输入信号进行压缩采样时,重构信号的均方误差仅为10-5量级。这验证了该采样系统的可行性,有效解决了多陪集采样系统的两个难题。At present,the compressed sampling system mainly includes three sampling system:random demodulator,modulated wideband converter and multi-coset sampling,among them,the system framework of multi-coset sampling is simple and has a high reconstruction success rate.But,the multi-coset sampling faces two difficulties in hardware implementation,one is that there is an upper limit on the input analog bandwidth of the low-speed analog-to-digital converter(ADC),and the other is it′s difficult to achieve precise delays on each channel.This paper draws on the ideal of modulated wideband converter which the input signal is pre-modulated before sampling,proposes the pre-modulated multi-coset sampling system which combines pre-modulation with multi-coset sampling.Before sampling,the generate periodic single-pulse sequences is generated by a random sequence generator in each channel of the sampling system,and the input signal is spectrally modulated to reduce the analog bandwidth of the signal before sampling.Then,the modulated signal is sampled by the low-speed ADC,and each channel of low-speed ADC and random sequence generator share a same control clock.Finally,the multiple signal classification algorithm(MUSIC)is used to reconstruct the input signal without distortion.The simulation results show that the mean square error of the reconstructed signal is at the order of 10-5 when the input signal is compressed and sampled at 15%Nyquist sampling rate.This verifies the feasibility of the sampling system in this paper,and the sampling system effectively overcome the two problems of the multi-coset sampling system.

关 键 词：压缩感知 多陪集采样 预调制 MUSIC算法 调制宽带转换器 

分 类 号：TN911[电子电信—通信与信息系统]