A new software package for communications systems analysis and design The TOPSIM computer program

The features and applications of the TOPSIM computer program for communications analysis and design are described. The program allows simulation of telecommunications systems in the time domain, responds to mnemonic-oriented free format command language, can be applied to a wide variety of communication systems, and is modular in the use of macro-models for expansion. TOPSIM can be used for nonlinear system element responses and has a complex envelope which permits elimination of the carrier frequency. Current limitations on the program are a lack of comprehensive macro-models, a postprocessor that is not user-friendly, and insufficient on-line processing. An expanded version of TOPSIM is being developed to extend the performance-evaluation algorithms and accommodate on-line postprocessing.