Application of fourier techniques to computer-aided design of electronic systems

At an early stage in the design of electronic systems, decisions have to be made concerning the function and performance of certain vital elements in the main signal path of the system, such as modulators and crucial filters. WASP (waveform and spectral-analysis program) is a computer program which allows the user to analyse a proposed system of cascaded modules and to extract the waveform and spectrum of the signal at any point in the chain. The program exploits the fast Fourier transform to calculate the spectrum at the output of the successive blocks of the system. The progress of the calculation is controlled by a simple set of orders, which are provided by the user as part of his data. The method is applicable to radar, communications, sonar and control systems, and the paper uses, as an example, the design of a digital f.m. radio system.