Discrete-Time Signals

In this chapter, Discrete-Time Signals, signal classification is first presented. Classification is essential to select appropriate procedure for its efficient processing. Classification is based on continuous, discrete, quantized continuous, digital, periodic, aperiodic, even-symmetric, odd-symmetric, energy, power, causal, noncausal, deterministic, random, bounded, and absolutely summable and absolutely square summable signals. Next, the basic signals, such as unit-impulse, unit-step, unit-ramp, sinusoids, and exponential, are presented. These signals are essential to approximate practical signals. The sampling of continuous signals, which is the first and major step in digital signal processing, and the aliasing effect due to sampling are presented. The basic operations, such as time shifting, time reversal, and time scaling, are described. Any signal processing task can be decomposed in terms of these basic operations.