Unequal Error Protection in Image Transmission Based on LDPC Codes

This paper investigates the performance of image transmission with unequal error protection (UEP) schemes based on irregular Low-Density Parity-Check (LDPC) codes. Firstly, the UEP is achieved by mapping different bits of the image bytes to different positions of LDPC codes, i.e. the more important bits in the image are mapped to the variable node with higher degrees in irregular LDPC codes, after the channel coding, we map the information bits into a power efficient QAM constellation and map the parity check bits into a spectral efficiency 16QAM constellation. Simulation results show that the UEP scheme is effective.