Tree-search decoding with path constraints for linear block codes

The A* algorithm is an efficient method for decoding short linear block code based on tree search. However, it may suffer very long decoding latency in the worst-case channel condition. In this paper, we propose to apply some restrictions on the Hamming weights of search paths in the tree-search decoding. Simulation results show that with proper selection of path constraints in the A* algorithm, the worst-case decoding complexity (or latency) can be significantly reduced with only slight sacrifice of the bit error rates.