Each book in the BASIC series has been designed to provide information on practical computing procedures for students and practising engineers, scientists and statisticians. The books explain how computing can be applied to the solution of real engineering and mathematical problems and provide working programs with full explanatory notes in order to help readers comprehend the principles of the subject and write their own computer programs. Digital signal processing is a rapidly developing field which uses computers, microprocessors and other types of digital hardware to analyze or modify electrical signals. The main aim of this book is to convey the essential ideas and potential of the process and then to illustrate implementation and design techniques using the BASIC programming language. The authors examine several techniques for the design of digital filters and provide an explanation of the discrete Fourier transform, its implementation by FFT algorithms and some of its applications, such as spectral analysis. Simple BASIC programs are provided in the text to illustrate digital signal processing methods by simulating their operation in real time.