The Research And Design Of High Precision Compression Sampling System

With the development of radio frequency communication technology, the carrier frequency of modulated signal keeps rising. It is difficult to achieve high-precision sampling by Nyquist sampling theorem. This is because the highest conversion bit of the existing commercial A/D converter is related to the sampling rate. The higher the sampling rate, the lower conversion bits of the A/D converter. In order to achieve high-precision sampling for multi-band signals in the broadband, it is necessary to reduce the sampling rate of the A/D converter. In recent years, Compressed Sensing is proposed to decrease sampling rate efficiently.This paper studies the theory of Compressed Sensing, and designs a high precision compressed sampling system.Firstly, the theory of Compressed Sensing is sketched in several main research contents. Secondly, the compressed sampling system is designed, and simulated by Matlab in specific parameters. Then, the performance of the system is analyzed based on simulation result. In the hardware circuit implementation, AD7760is system’s A/D converter, which is a24-bit Σ-A A/D converter. So the system has high precision characteristic. The hardware circuit consists of analog-to-digital conversion circuit and digital signal processing circuit. They are used to complete signal compression sampling and signal reconstruction. In addition, the interface circuit of A/D converter is designed and implemented by FPGA. On this basis, we measured the quantization SNR of A/D converter.