Thresholds Calculation of LDPC Code Ensembles Using a Novel Gaussian Approximation Algorithm

A novel Gaussian approximation algorithm is proposed for calculating the thresholds of low-density parity- check (LDPC) code ensembles under sum-product decoding. The updating rules of means and error probability are derived. Numerical results show that the thresholds obtained by the proposed algorithm closely coincide with the values computed by density evolution (DE). Moreover, our algorithm can calculate the thresholds of irregular LDPC codes with higher accuracy than the algorithm proposed by Lehmann and Maggio.