【作者】 于维双；

【导师】 潘明海；

【作者基本信息】 燕山大学 ， 电路与系统， 2005， 硕士

【摘要】 本文对宽带信号的多通道高精度采样及其重构算法进行了理论分析、算法设计及仿真验证,采用 DSP 系统实现了宽带信号的高精度采样和实时重构。 宽带信号的高精度采样及其重构问题是现代通信系统、雷达系统中的“宽带数字接收机”和高性能仪器仪表(如数字滤波器、频谱分析仪等)系统中的关键技术。在 DSP 系统中,经常需要对宽带的模拟信号进行采样,而当信号带宽较大时,因受 A/D 器件转换速率的限制以及转换速率与转换精度之间的矛盾,用单个的A/D器件实现信号的高精度采样是十分困难的。 为解决转换速率与信号带宽、以及转换速率与转换精度之间的矛盾,本文分别对时域多通道采样方法和频域多通道采样方法进行了研究,讨论如何解决宽带信号的高精度采样和实时重构问题。时域多通道采样方法采用多个通道在不同时刻对宽带信号进行采样,降低对A/D器件速度的要求,以达到提高采样精度的目的。频域多通道采样方法的基本思想是将宽带信号分解为若干个频带较窄的子带信号,对每个子带信号分别用低速、高精度的 A/D 器件进行采样,将获得的各个子带信号的采样数据经过内插、镜像滤波处理之后进行重构,从而实现对原宽带模拟信号的高精度采样。 计算机仿真结果证明,时域多通道采样方法和频域多通道采样方法均可以有效地减小频谱失真,实现信号的高精度采样和实时重构。更多还原

【Abstract】 This paper presents the algorithms of wideband signal Multi-channel high accuracy sampling and signal reconstruction, in which both the arithmetic design and the simulation results are included. The algorithms of wideband signal high accuracy sampling and real-time reconstruction have been realized based on DSP system. Wideband signal high accuracy sampling and signal reconstruction are the key technique of wideband digital receiver and high-accuracy instrument (digital filter and spectrum analyzer) in modern communication system and radar system. In DSP systems, the technique of wideband signal high accuracy sampling is often used. However ADC can not take sampling rate and accuracy into consideration, and high accuracy sampling is very difficult with a single ADC when signal bandwidth is very wide. In order to settle the dilemma between sampling rate and bandwidth, sampling rate and conversion accuracy, this paper studies through time domain multi-channel sampling method and frequency domian multi-channel sampling method and discusses about how to solve the problem of wideband signal high accuracy sampling and real-time reconstruction. In time domain multi-channel sampling method, wideband signal are used to carry out sampling at different times in several channels, aiming to reduce the requirement for sampling rate and to improve sampling accuracy. In frequency domain multi-channel sampling method, the wideband signal is divided into several narrow-band subband signals, each subband signal is sampled by a low sampling rate but high accuracy ADC. Then using these sampling data of subband signals to reconstruction signal through the process of interpolation and anti-imaging filtering. After completing the above procedures, high sampling of the original wideband analog signal is realized. Computer simulation results have shown that both time domain multi-channel sampling method and frequency domain multi-channel sampling method can reduce spectrum distortion effectively and realize signal high accuracy sampling and real-time reconstruction.更多还原