CE 5310 Lecture Notes - Lecture 16: Saskatchewan Highway 2, Side Lobe, Short-Time Fourier Transform
Document Summary
Discrete time signal processing is slightly different from the term digital time processing (dsp), which refers to the processing of discrete time signal which is also quantized. Specifically, a discrete time system h takes input signal x[n], and creates output signal y[n] in response of x[n]. The linearity of a system is one of the most important properties that a system can have because some of the mathematical tools we develop apply only to linear systems. A system is causal if current outputs do not depend on future inputs, i. e. , for every n, y[n] depends on x[m], m n. For systems where the variable n is indeed a time variable, such as a stress history, a physically realizable system has to be causal. However, if data x[n] are acquired and stored before processing, such like a stored voice signal or image signal, these systems can be noncausal without violating physical laws of nature.
