摘要
模拟信号的抽样(采样)实现了时域的离散。由于其固有的乘积环节,抽样实现了频谱的线性搬移。作者在文中分析了理想和实际抽样中的频谱变换过程,给出了抽样在调制、下变频中的应用,同时阐明了当已调窄带信号的载波频率等于其带宽的整数倍并以带宽为抽样频率抽样时通过低通滤波实现解调的原理。
Sampling process realizes the analog signal discretization on the time domain, and for its inherent multiplying function, it also completes the linear spectrum conversion on frequency domain. The paper analyzes the spectrum conversion process of ideal and practical sampling, and reasons out the application on modulating and down frequency conversion. In the last, it testifies the demodulation theorem by lowpass when narrow band modulated signal whose centre frequency is whole number times of its band sampled by the equal frequency to its band.
出处
《陕西科技大学学报（自然科学版）》
2005年第4期89-93,共5页
Journal of Shaanxi University of Science & Technology
关键词
采样
频谱变换
解调
sampling
spectrum conversion
demodulation
