CUSTOM DSP DESIGN OF A GSM SPEECH CODER

The GSM speech coder for digital mobile telephones has been designed o n a custom DSP using an environment for development of arbitrary proce ssor architectures. A netlist of the speech coder has been generated f rom a high level description in a presented design environment. Improv ement of the performance both by modifying the high level description and by hand optimization of the microcode is discussed. Advantages of a user interactive system were stepwise refinement leads to a competit ive result is thus demonstrated. Simulation has been performed at algo rithm, microcode, and transistor level for consistency check. To avoid dependency of a specific vendor the design environment allows impleme ntation in various technologies and a netlist for a Plessey gate array has been generated as an example.