|
A discrete signal or discrete-time signal is a time series consisting of a sequence of quantities. In other words, it is a time series that is a function over a domain of integers. Unlike a continuous-time signal, a discrete-time signal is not a function of a continuous argument; however, it may have been obtained by sampling from a continuous-time signal, and then each value in the sequence is called a sample. When a discrete-time signal obtained by sampling a sequence corresponds to uniformly spaced times, it has an associated sampling rate; the sampling rate is not apparent in the data sequence, and so needs to be associated as a characteristic unit of the system. ==Acquisition== Discrete-time signals may have several origins, but can usually be classified into one of two groups:〔"Digital Signal Processing" Prentice Hall - Pages 11-12〕 * By acquiring values of an analog signal at constant or variable rate. This process is called sampling.〔"Digital Signal Processing: Instant access." Butterworth-Heinemann - Page 8〕 * By observing an inherently discrete-time process, such as the weekly peak value of a particular economic indicator. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Discrete-time signal」の詳細全文を読む スポンサード リンク
|