ABSTRACT
IN THIS BOOK, we look for the patterns that occur in the signals generated bythe world around us and try to develop stochastic models for them. We then use these models to detect patterns and structures in these signals, even when, as usually happens, they are ambiguous or obscured by various distortions. In this chapter, we begin with a well-known type of signal and the simplest patterns in it. The “signals” are just the strings of English characters found in any written English text. Any other language would be just as good (see Figure 1.1) if it is written with a small alphabet (e.g., Chinese would work a bit differently). Such signals are examples of discrete one-dimensional signals; they are made up of sequences {an} whose elements lie in a finite set.
