Signal Constellation Design Tool: A Case Study in User Interface Synthesis

Signal constellation design is a major subtask of constructing an efficient communication system; it essentially entails trading-off error frequency against information throughput, a chief occupation of modem designers. We propose and implement an interactive tool for designing and simulating arbitrary signal constellations. 'To construct the user interface we have utilized Interface Builder, a new interactive tool that greatly facilitates the synthesis of arbitrary user interfaces through an object-oriented methodology. Using the Interface Builder package and the Signal Constellation Design Tool as the target prototype, we show how an order-of-magnitude improvement can be achieved in the effort required to produce a complex user interface. Our secondary goal is to try to dispel some of the mystique surrounding user interface synthesis on state-of-the-art workstations by describing in detail the construction of an interactive tool for computer-assisted learning. 1. Introduction Signal constellation design is a major part of constructing an efficient communication system. This task essentially entails trading off error frequency against information throughput, a chief occupation of modem designers. We propose and implement an interactive tool for designing and simulating arbitrary signal constellations. While the actual code that simulates signal constellations is rather trivial in itself, the user interface to this code is quite complex. To design and construct this user interface we have used Interface Builder, a new interactive tool that greatly facilitates the synthesis of user interfaces through an object-oriented methodology. Using the Interface Builder package and the Signal Constellation Design Tool as the target prototype, we show how an order-of-magnitude improvement can be achieved in the effort required to produce a complex user interface, and then draw some conclusions regarding the synthesis of user interfaces in general. Our secondary goal is to try to dispel some of the mystique surrounding user interface synthesis on state-of-the-art workstations. Many otherwise informed researchers have very little experience in user-interface design, and consequently view user interface design as some sort of a black art, best left to specialized hackers to dabble in. By user interface design I mean a collection of functionality (running on a bit-mapped display workstation with a mouse) that interacts with the user in a friendly manner via menus, scroll bars, control buttons, icons, mouse clicks, and key strokes. We intend to show that, quite to the contrary of these myths, given the proper tools and methodology, the synthesis of complex user interfaces could be rather trivial. As a case …