Design of a Fast Sequential Decoding Algorithm Based on Dynamic Searching Strategy

This paper presents a new sequential decoding algorithm based on dynamic searching strategy to improve decoding efficiency. The searching strategy is to exploit both sorting and path recording techniques. By means of sorting, we cun identify the correct path in a very fast way and then, by path recording, we can recover the bit sequence without degmding decoding performance. We also develop a conditional resetting scheme to overcome the buffer overflow problem encountered in conventional sequential decoding algorithms. Simulation results show that for a given code, decoding efficiency remains the same as that obtained from maximum likelihood function by appropriately selecting sorting length and decoding depth. In addition, this algrithm can be mapped onto an area-efflcient VLSI architecture to implement long constraint length convolutional decoders for high-speed digital communications.