Alternative good LDPC codes for DVB-S2

This paper reveals that the current LDPC codes in DVB-S2 are not good, since they have the codes of minimum weight of 5, which leads to their BER can not satisfy the requirements of DVB-S2. This paper develops an algorithm to estimate the minimum weight of LDPC codes based on generator matrices. Using it, we can find the minimum weight problem of the current LDPC codes in DVB-S2. To enhance the minimum weight problem of the LDPC codes, we propose a new approach to construct the encodable irregular QC codes, which can not produce new short girths and can have much larger minimum weight and minimum distance of the codes. Simulations verify the construction of alternative QC LDPC codes for DVB-S2 to be valid, since better BER performance than that of existing irregular LDPC codes of DVB-S2 is obtained.