Sampling is the bridge between analog source signal and digital signal.With the rapid progress of information technologies

the demands for information are increasing dramatically.So the existing systems are very difficult to meet the challenges of high speed sampling

large volume data transmission and storage.How to acquire information in signal efficiently is an urgent problem in electronic information fields.In recent years

an emerging theory of signal acquirement——compressed sensing (CS) provides a golden opportunity for solving this problem.This paper reviews the theoretical framework and the key technical problems of compressed sensing and introduces the latest developments of signal sparse representation

design of measurement matrix and reconstruction algorithm.Then this paper also reviews several open problems in CS theory and discusses the existing difficult problems.In the end

the application fields of compressed sensing are introduced.