New viterbi decoder design for code rate K/N

A novel VLSI architecture is proposed for implementing a long constraint length Viterbi Decoder (VD) for code rate k/n. This architecture is based on the encoding structure where k input bits are shifted into k shift registers in each cycle. The architecture is designed in a hierarchical manner by breaking the system into several levels and designing each level independently. At each level, the number of computation units, the interconnection between the units as well as allocation and scheduling issues have been determined. In-place storage of accumulated path metrics and trace back implementation of the survivor memory have also been addressed. The resulting architecture is regular, flexible and achieves a better than linear tradeoff between hardware complexity and computation time.