Efficient Maximum-Likelihood Soft-Decision Decoding of Linear Block Codes Using Algorithm A*
Yunghsiang Sam Han, Carlos R. P. Hartmann, Chih-Chieh Chen · 2005
In this paper we present a novel maximum-likelihood soft-decision decoding algorithm for linear block codes. The approach used here is to convert the decoding problem into a search problem through a graph which is a trellis for an equivalent code of the transmitted code. Algorithm A* is employed to search through this graph. This search is guided by an evaluation function f defined to take advantage of the information provided by the received vector and the inherent properties of the transmitted code. This function f is used to drastically reduce the search space and to make the decoding efforts of this decoding algorithm adaptable to the noise level. Simulation results for the (104, 52) binary extended quadratic residue code and the (128,64) binary extended BCH code are given.