This course introduces the basic theory and knowledge of discrete-time signal processing. In particular, the representation, characteristics and analysis of discrete time signals and systems in time-domain, frequency domain and z-transform domain, Fourier transform and its fast implementation, filter structures and filter designs are introduced. Knowledge points include discrete-time Fourier transform, discrete Fourier transform, z-transform, linear time-invariant system, finite impulse response filters and infinite impulse response filters.