An Open-Ended Computer Package for Signal Processing Teaching and Design

Tutorial, design, and project work in signal processing courses require substantial computational effort and data handling, and rely on computer support. The requirements on the support software of modularity, friendliness, good documentation, and extensibility are identified. This paper describes the structure and underlying methodology of a package written in Basic to meet these needs. It consists of four clearly defined hierarchical layers and has a virtual graphics facility. The principal properties of the package are completely interactive operation, a modular structure, ease of addition of new facilities, well-defined ground rules, and standardized documentation. The user interface is simple and friendly. The data structure is easily visualized and remembered. Program development has taken place through student involvement within strict ground rules. The package now comprises over 300 subroutines which can be invoked interactively. Experience in the use and management of the package is discussed. Digital filter design via the bilinear z transform is used as an example of a problem solution. The documentation for one of the subroutines illustrates the standards that are enforced. The methods adopted to overcome the well-known difficulties encountered when writing a large package in Basic are discussed.