Robust airborne image transmission using joint source-channel coding with UEP

Airborne image service plays an important role in both government and commercial applications. These applications require reliable transmission of compressed images over wireless channels. Various image compression and wireless channel coding schemes have been separately developed in the past decades. However, the transmission quality supported by the existing algorithms can be attenuated by many atmospheric factors due to wireless channels. In this paper, we design a joint source-channel coding framework for transmitting compressed image signals over airborne communication channels in order to further improve the quality of image transmission service. When transmitting the compressed image data, not all information bits are equally important. Due to the inherent nature that compressed images are highly correlated, one bit error can lead to a complete failure of reconstruction of the image sources. In the proposed framework, an unequal error protection (UEP) is included based on the importance and correlation of the information bits. We evaluate rate-compatible punctured convolutional (RCPC) channel coding technique combined with both UEP and equal error protection (EEP) for the set partitioning in hierarchical trees (SPIHT) image compression scheme. Comprehensive simulations are performed for the proposed airborne image transmission system, and the results demonstrate a good error robustness of proposed schemes.