This thesis introduces rapid prototyping methodology which overcomes important barriers in the design and implementation of digital signal processing (DSP) algorithms and systems on embedded hardware platforms, such as cellular phones. This thesis describes rapid prototyping in terms of a simulation/prototype bridge and in terms of appropriate language design. The simulation/prototype bridge combines the strengths of simulation and of prototyping, allowing the designer to develop and evaluate next-generation communications systems partly in simulation on a host computer, and partly as a prototype on embedded hardware. Appropriate language design allows engineers to express a communications system as a block diagram, in which each block represents an algorithm specified by a set of equations. Software tools developed for this thesis implement both concepts, and have been successfully used in the development of a type-based detector for a code-division multiple access (CDMA) cellular wireless communications system.