Applications in Signal Processing and Measuring Techniques

Abstract

In the technique of communication and the broad area of measurement one is frequently faced with the task of influencing a signal in a certain manner or modifying it, for instance delaying it, changing its spectrum by a frequency filter (to clear it from unwanted spectral components, for example), or modulating it with another signal, etc. Generally, the signals are represented by time-varying electrical voltages or currents, even if the original information they contain is acoustical, optical or of an otherwise non-electric nature. Hence the methods of signal processing are largely electrical if not to say electronic, which means they make use of electric circuit components, electric lines, switches, etc. More recently, however, the technical development of the glass fibre has opened up the possibility of transmitting signals in optical form over large distances. For this reason, optical methods of signal processing have also found a new raison d’etre and are gaining in importance.