Automated Generation of Viterbi Decoders

In this report we explore the design automation of Viterbi Decoders. The task of designing a Viterbi Decoder is highly repetitive in itself. The intention is to systematize and automate the design process of Viterbi decoders. There are various possible designs of Viterbi Decoder. A comprehensive design space exploration is done to identify the available design options. Analysis of various designs is done to establish their merits and demerits. For various designs, quantitative relations between decoder parameters and its performance are obtained. Automation requires specifying optimum design for given requirements. Implementation results of various designs are analyzed to establish the suitability of the designs for particular requirements. There are limitations in physical implementation of the designs. The physical implementation issues are also discussed. Automation of the design can be done at various levels of abstraction. Analysis and comparison of various automation approaches is done. The automation tool is implemented and is used to generate various designs. The generated designs are synthesized to get the timing and area figures. This information is used to calibrate and refine the tool. Finally, results obtained from physical implementation of generated designs are analyzed. From the results and analysis a few guidelines are derived for the design of Viterbi Decoders. Conclusions: The automation tool is capable of generating designs for a wide range of parameters. The designs are generated taking into consideration the limitations of physical implementation such as SRAM access frequency and SRAM datawidth. In terms of throughput and area the generated designs are comparative to the handcoded ones. As the tool also considered technology related performance database, realistic designs are generated. By using the tool, design time can be drastically reduced.