scholarly journals Research on unequal error protection with punctured turbo codes in jpeg image transmission system

2007 ◽  
Vol 4 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Moulay Lakhdar ◽  
R. Méliani ◽  
M. Kandouci
Keyword(s):  
Turbo Codes ◽  
Viterbi Algorithm ◽  
Turbo Code ◽  
Signal To Noise Ratio ◽  
Image Transmission ◽  
Unequal Error Protection ◽  
Channel Noise ◽  
Error Protection ◽  
Jpeg Image ◽  
Highly Sensitive

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.

scholarly journals Compartive study on performance of the LDPC codes and turbo-codes used in the image transmission in the gaussian and rayleigh channel

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
Fayssal Menezla ◽  
Rachida Meliani ◽  
Zoubir Mahdjoub
Keyword(s):  
Turbo Codes ◽  
Turbo Code ◽  
Digital Signal ◽  
Image Transmission ◽  
Channel Noise ◽  
Gaussian Channel ◽  
Image Correction ◽  
Rayleigh Channel ◽  
Number Of Iterations

The errors induced by channel noise influence on the quality of digital transmission. The latter depends on the probability of errors in the transmitted symbols. To control these errors, a technique of digital signal processing is used, including the information code to be transmitted. As these techniques are used for controlling the transmssion, they are called "channel encoding". In this paper, we introduced and studied two major correction code families' error; LDPC (Low Density Parity Check) and the turbo code. We used our simulation model to evaluate the performance of a Gaussian channel. The results show the effect of iterative LDPC and Turbo code on the transmission and quality of information. Our numerical simulation has shown that the resulting image was corrected gradually as the number of iterations increases for both channels. On the Rayleigh channel, the image correction is obtained for a higher number of iterations over the Gaussian channel.

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