提出了一种联合信源信道编码(JSCC)方案。首先,构造了一种具有重量递增奇偶校验矩阵的非规则LDPC码(WIPC-LDPC),实现非规则LDPC(Irregular LDPC)码比特节点按列重递增的顺序排列。然后,针对JPEG2000码流分层结构的特点,把不同质量层的JPEG2000码流成功地映射到WIPC-LDPC不同度数的比特节点上,以达到对不同重要级别码流的不等错误保护(UEP),从而达到优化重建图像质量和视觉效果的目的。仿真结果表明,与采用随机构造校验矩阵的非规则LDPC码进行等错误保护(EEP),以及采用RCPC、RS码进行不等错误保护的JPEG2000码流相比,JSCC方案提高了重建图像的PSNR,改善了重建图像的主观视觉效果。
Utilizing the characteristic of JPEG2000 code stream format, a joint source channel coding (JSCC) scheme was proposed in this paper. A novel irregular LDPC with weight-increasing parity-check (WIPC) matrix (WIPC-LDPC) was first put forward, which can simply realize unequal error protection (UEP) characteristic. Then the different significant JPEG2000 code streams were coded by weight-increasing parity-check (WIPC) irregular LDPC with dissimilar degree bit nodes to realize UEP scheme. Simulation results show that the proposed JSCC can realize robust image transmission and outperforms other JSCC schemes proposed before.