A memory-efficient architecture for low latency Viterbi decoders

A memory-efficient Viterbi decoder (VD) named modified state exchange (MSE) is proposed using pre-trace back technique to obtain the decoded data by blocks. Since the architecture of MSE can record the “survival state number,” which can also be the resulted decoded data, no decision bit is required during trace back and decoding. Therefore, the power and chip area of the survivor memory unit in the MSE method are smaller than those of the existing trace back approaches. The VD using MSE approach for (2, 1, 6) convolutional code was designed using TSMC 0.18µm 1P6M CMOS technology. The core area is 0.69mm2 with power consumption of 58mW at 100MHz.