High-speed VLSI architectures for Huffman and Viterbi decoders

Pipelined and parallel architectures for high-speed implementation of Huffman and Viterbi decoders (both of which belong to the class of tree-based decoders) are presented. Huffman decoders are used for lossless compression. The Viterbi decoder is commonly used in communications systems. The achievable speed in these decoders is inherently limited due to the sequential nature of their computation. This speed limitation is overcome using a previously proposed technique of look-ahead computation. The incremental computation technique is used to obtain efficient parallel (or block) implementations. The decomposition technique is exploited to reduce the hardware complexity in pipelined Viterbi decoders, but not in Huffman decoders. Logic minimization is used to reduce the hardware overhead complexity in pipelined Huffman decoders