ABSTRACT
This chapter covers deterministic linear systems, time-domain analysis, and frequency-domain analysis. It discusses linear systems with white noise input, and equivalent noise bandwidth. The chapter highlights the relationships of power spectra, means and autocorrelations between the input and output. For "power" relationships, the output is the two-fold convolution in time domain of the input and the system's impulse response function. Powerful methods are available for linear time-invariant (LTI) systems. Time invariance of a system, steady state of a deterministic time function, and stationarity of a random process are similar concepts. An LTI system can be represented in terms of its: impulse response function h(t) in time domain; frequency response functionH(ω) in frequency domain as the Fourier transform of h(t) or transfer functionH(s) as the Laplace transform of h(t). Frequency-domain analysis is usually simpler than time-domain analysis in the cases where the frequency response function of the system and the input power spectrum are both rational.
