Serial Update Scheduling Based on Weighted Average Message of Check Nodes for LDPC Codes
Xingcheng Liu · Acta Scientiarum Naturalium Universitatis Sunyatseni · 2010
For short and middle length LDPC codes,the oscillation of LLR owing to cycles degrades the performance of BP algorithm.In order to minimize the oscillation of LLR during BP decoding process,an improved BP algorithm with serial update scheduling using weighted average message to update the message of check-to-variable node is proposed.Currently computed message of check-to-variable node and the message of old check-to-variable node are weighted and then added up to update the message of check-to-variable node.By higher weighted currently computed message of check-to-variable node than the message of old check-to-variable node,the improved algorithm effectively minimizes oscillation of LLR,at the same time,keeps normal BP message propagation and low compute complexity.Simulation results show that,for short and middle length LDPC codes,the improved algorithm achieves more noticeable error performance than CSBP algorithm at middle to high signal to noise ratio.