Lower power Viterbi decoder architecture with a new clock-gating trace-back unit

This paper presents a new algorithm on lower-power survivor path memory implementation of the trace-back systolic array Viterbi algorithm. A novel idea is to reuse the already-generated trace-back routes to reduce the number of trace-back operations. It results in increasing the area of spurious switching activity region, and further reducing the switching activity with gated-clocks during trace-back operation. With the SYNOPSYS power estimation tool, DesignPower, our experimental result shows on the average 40% reduction in power with the same latency at a cost of 23% increase in area against the trace-back unit introduced by Truong et al. (1992). The proposed survivor memory scheme can be applied to the digital communication systems for targeting low power consumption.