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A Low-Power Self-Timed Viterbi Decoder
P.A. Riocreux, L.E.M. Brackenbury, M. Cumpstey, S.B. Furber
Viterbi decoders are used for decoding data encoded using convolutional forward error correction codes or data that suffers from inter-symbol interference. They occur in a large proportion of digital transmission and digital recording systems, including digital mobile telephony and digital TV broadcast, CD-ROM and magnetic disk reading. This paper describes a design for a self-timed Viterbi decoder. The new design is based upon serial, unary arithmetic for the manipulation and storage of metrics. In the trace-back system, multiple concurrent trace-backs may be running and trace-backs are terminated as soon as they cease to be useful. The new architecture occupies between 29% and 23% less area than a selection of synchronous implementations with the same design parameters which use the same process and cell-library.