Modified Decoding Algorithm for Irregular Repeat Accumulate Codes in Wireless Sensor System

IRA (Irregular Repeat Accumulate) codes can be well utilized in wireless sensor systems, computer storage systems due to their approaching to Shannon limit by means of prominent decoding algorithm and etc. Belief propagation algorithm is the best decoding algorithm for IRA codes, but there is great hardware complexity with implementation. Minimum-sum algorithm modifies belief propagation algorithm at the cost of decoding performance. To utilize both normalized factor and offset factor, a modified low complexity algorithm is proposed to improve decoding performance better. Simulation results show that if BER requests to be 10, the encoding gain of the proposed decoding algorithm can be 0.5dB and 0.4dB better than normalized algorithm and offset algorithm respectively, and 0.1dB worse than belief propagation algorithm only.