Research on Unequal Error Protection with Punctured Turbo Codes in JPEG Image Transmission System

Abstract

An investigation of Unequal Error Protection (UEP) methods applied to JPEG image transmission using turbo codes is presented. The JPEG image is partitioned into two groups, i.e., DC components and AC components according to their respective sensitivity to channel noise. The highly sensitive DC components are better protected with a lower coding rate, while the less sensitive AC components use a higher coding rate. While we use the s-random interleaver and s-random odd-even interleaver combined with odd-even puncturing, we can fix easily the local rate of turbo-code. We propose to modify the design of s-random interleaver to fix the number of parity bits. A new UEP scheme for the Soft Output Viterbi Algorithm (SOVA) is also proposed to improve the performances in terms of Bit Error Rate (BER) and Peak Signal to Noise Ratio (PSNR). Simulation results are given to demonstrate how the UEP schemes outperforms the equal error protection (EEP) scheme in terms of BER and PSNR.