Improved sub-block encoder of irregular LDPC code for image transmission

This paper presents irregular low-density parity-check (LDPC) code for image transmission system with any desired code lengths. Parity position of sub-block encoder is easily constructed over additive white Gaussian noise (AWGN) channel. The code is used as forward error correction (FEC) technique to protect transmitted source data over the channel. The sub-block encoder is designed with various AWGNs at three code lengths of 522, 2,021 and 4,183. The proposed irregular LDPC code reduces bit error when the code length increases. The performance is evaluated by bit error rate (BER) improvement 33.33% and peak signal-to-noise ratio (PSNR) more than 30 at SNR equals 7 dB.