We propose a hybrid joint source-channel coding (JSCC) scheme, in which the conventional digital communication scheme is complemented with a generative refinement component to improve the perceptual quality of the reconstruction. The input image is decomposed into two components: the first is a coarse compressed version, and is transmitted following the conventional separation based approach. An additional component is obtained through the diffusion process by adding independent Gaussian noise to the input image, and is transmitted using DeepJSCC. The decoder combines the two signals to produce a high quality reconstruction of the source. Experimental results show that the hybrid design provides bandwidth savings and enables graceful performance improvement as the channel quality improves.

翻译：我们提出了一种混合型联合信源信道编码（JSCC）方案，该方案在传统数字通信系统中引入生成式细化组件，以提升重建图像的感知质量。输入图像被分解为两个部分：第一部分是经过粗压缩的版本，通过传统的分离式方法进行传输；第二部分则利用扩散过程，通过向输入图像添加独立高斯噪声获得，并采用DeepJSCC进行传输。解码器将两路信号合并，生成高质量的信源重建。实验结果表明，该混合设计能够节省带宽，并随着信道质量的改善实现性能的逐步提升。