Fast sequential decoding algorithm based on dynamic searching strategy

The authors present 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, it is possible to identify the correct path in a very fast way and then, by path recording, the bit sequence can be recovered without degrading decoding performance. The authors 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, the decoding efficiency remains the same as that obtained from maximum likelihood function by appropriately selecting sorting length and decoding depth. In addition, this algorithm can easily be mapped onto an area-efficient VLSI architecture to implement long constraint length convolutional decoders for high-speed digital communications.