CAJ | 학술논문

在雷达技术领域得到高度关注的压缩感知理论,能够有效地降低高分辨率雷达成像系统的数据率,解决雷达系统中超大数据量的采集、存储与传输问题。宽带雷达回波在信号的幅度延时基上具有稀疏表示。基于这一特性,可以使用压缩感知理论通过降维采样大大减少数据量。针对降维采样后信号重建问题,文中研究了一种基于协方差准则循环迭代的稀疏参数估计方法(SPICE)。文中首先根据雷达回波信号的特征构造了波形延时稀疏字典,再通过随机采样对数据进行压缩,最后将 SPICE作为信号重构算法引入雷达回波压缩感知处理过程中。仿真结果表明利用 SPICE参数估计方法,可使得压缩率降到很小的程度,且降低重建信号相对原始信号的误差。此外,SPICE算法本身具有数据自适应特性,不需要再根据信号特征选取循环结束条件。仿真结果表明,算法具有较快的收敛速度,能够在较短的时间内准确估计出雷达回波的稀疏参数。
재뢰체기술영역득도고도관주적압축감지이론,능구유효지강저고분변솔뢰체성상계통적수거솔,해결뢰체계통중초대수거량적채집、존저여전수문제。관대뢰체회파재신호적폭도연시기상구유희소표시。기우저일특성,가이사용압축감지이론통과강유채양대대감소수거량。침대강유채양후신호중건문제,문중연구료일충기우협방차준칙순배질대적희소삼수고계방법(SPICE)。문중수선근거뢰체회파신호적특정구조료파형연시희소자전,재통과수궤채양대수거진행압축,최후장 SPICE작위신호중구산법인입뢰체회파압축감지처리과정중。방진결과표명이용 SPICE삼수고계방법,가사득압축솔강도흔소적정도,차강저중건신호상대원시신호적오차。차외,SPICE산법본신구유수거자괄응특성,불수요재근거신호특정선취순배결속조건。방진결과표명,산법구유교쾌적수렴속도,능구재교단적시간내준학고계출뢰체회파적희소삼수。
Compressive sensing(CS)theory is highly focused in radar community over the last decade.Its incoherence measurement process can effectively reduce the data rate of high-resolution imaging radar system.Consequently, compressive sensing theory can be used to release the burden of radar system on huge amount of data sampling, storage and transmission.This paper concentrates on finding a kind of proper reconstruction algorithm when dealing with the radar echo with compressive sensing theory.The broadband radar echo has a sparse representation on the amplitude-delay sparse dictionary.Compressive sensing theory can greatly reduce the amount of data through dimension reduction sampling based on this feature.After the dimension reduction sampling,we need to find a proper algorithm to reconstruct the original signal.In order to solve this problem,a kind of sparse iterative covariance-based estimation method (SPICE)is studied in this paper.SPICE is computationally quite efficient and enjoys global convergence properties.Besides,this algorithm does not require any subtle choices of user parameters and can be used in many fields,such as spectral analysis,array processing,astronautic applications and so on.In this paper,we apply this algorithm to wide-band radar,which is widely used in both military and civil fields.During the simulation, an amplitude-delay sparse dictionary was constructed according to the characteristics of the radar echo signal waveform firstly.Then,the amount of data was compressed through random sampling.Finally,SPICE,as the signal reconstruction algorithm,was introduced into the process of the radar echo based on compressive sensing theory.The simulation results show that the usage of SPICE parameter estimation makes the degree of compression ratio very small and the relative error between reconstruction signal and original signal is also small.In addition,the SPICE al-gorithm itself has data adaptive features,which is an important advantage different from other kinds of algorithm.As a consequence,there is no need to select end conditions according to the signal feature.At the same time,the algorithm also converges very fast,and can estimate the sparse parameters of radar echoes in a relatively short period of time.This advantage can meet the requirement of real-time for wide-band radar target detection.