基于MWC宽带压缩采样信号的DSP重构

DSP spectrum reconstruction system of compressive sampling based on modulated wideband converter

摘要:

高速宽带数字通信系统是无线通信的发展趋势，需要高质量的通信信道保证。在无线通信领域，存在着频谱资源日益匮乏、信道不稳定、利用率低造成数据传输质量不高的问题。基于压缩感知技术的宽带调制转换器(MWC)能够用于无线频谱的快速检测，为频谱资源的合理配置和监管提供了一种新的实现途径。本文通过研究MWC及其实现技术，在调制宽带转换器采样的基础上提出了一种改进多重信号分类算法的宽带频谱快速感知方法，基于DSP芯片设计实现了MWC宽带采样信号的重构系统。整个感知过程无须重构原始波形，无须计算频谱，大大降低了计算量，提高了感知效率。仿真结果表明，在低信噪比的情况下，该算法仍具有很好的检测性能。测试表明，该系统可以准确地感知实时频谱占用和频谱空洞位置。

Abstract:

High speed wideband digital communication system is the development trend of wireless communication which needs the guarantee of high quality communication channel. Aiming at the problem of exorbitant sampling rate and long sensing time in wideband sensing，a wideband spectrum sensing method using improved multiple signals classification based on Modulated Wideband Converter(MWC) is proposed．Based on compressive sampling，the MWC sampling method can implement sampling at a rate lower than what is required by Nyquist theory. A spectrum reconstruction system is designed based on MWC，that can reconstruct the sparse-frequency signal at a rate lower than Nyquist-frequency. The amount of calculations is reduced，because it neither needs to recover original wave，nor calculates PSDs in the whole process．The complexity of sensing method is low，so that it can increase the sensing efficiency．The results show a reliable detection even under low signal to noise ratio．