Study on sub-block encoder of LDPC code with OFDM for image transmission

This paper presents 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 Rayleigh fading 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 OFDM modulation at various noises for two code lengths of 1,057 and 4,376 at high code rate is 0.935. The proposed LDPC code with OFDM modulation can reduce bit error when the code length increases. The performance is evaluated by bit error rate (BER) improvement 80% and peak signal-to-noise ratio (PSNR) more than 30 at SNR equals 8 dB.