Joint Source Channel Decoding Exploiting 2D Source Correlation with Parameter Estimation for Image Transmission over Rayleigh Fading Channels

This  paper  investigates  the  performance  of  a  2- Dimensional  (2D)  Joint  Source  Channel  Coding  (JSCC)  system assisted  with  parameter  estimation  for  2D  image  transmission over  an  Additive  White  Gaussian  Noise  (AWGN)  channel  and a  Rayleigh  fading  channel.  Baum-Welsh  Algorithm  (BWA)  is employed  in  the  proposed  2D  JSCC  system  to  estimate  the source correlation statistics during channel decoding. The source correlation is then exploited during channel decoding using a Modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. The performance of the 2D JSCC system with the BWA-based parameter estimation technique (2D-JSCC-PET1) is evaluated via image transmission simulations.  Two  images,  each  exhibits  strong  and weak  source  correlation  are  considered  in  the  evaluation  by measuring the Peak Signal Noise Ratio of the decoded images at the  receiver.  The proposed 2D-JSCC-PET1 system is compared with various benchmark systems. Simulation results reveal that the 2D-JSCC-PET1 system outperforms the other benchmark systems (performance gain of 4.23 dB over the 2D-JSCC-PET2 system and 6.10 dB over the 2D JSCC system).  The proposed system also can perform very close to the ideal 2D JSCC system relying on the assumption of perfect source correlation knowledge at the receiver that shown only 0.88 dB difference in performance gain

Low complexity technique exploiting 2D source correlation using single parity check codes

This paper proposes a low complexity joint source-channel coding (JSCC) technique that can well exploit two-dimensional (2D) source correlation using turbo single parity check (SPC) codes. Based on similar structure of the product accumulate code, a rate-1 inner code is serially concatenated to the turbo SPC code structure in order to overcome the high error floor issue of turbo SPC codes. The 2D source correlation, horizontal and vertical directions of the source are exploited during the decoding process. In order to exploit the source statistics (i.e. transition probabilities), a decoding algorithm based on modified check operation is proposed. This modified check operation has significantly lower computational complexity than the previous technique that based on modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. Simulation results reveal that the proposed technique that based on modified check operation achieves about 4.5 times lower computational complexity than the technique that based on modified BCJR algorithm. In addition to the lower computational complexity, the proposed JSCC technique can achieve optimal performance, similar with the technique that based on modified BCJR algorithm. The interesting features of low computational complexity and high performance of the proposed technique is important in designing JSCC system exploiting higher dimensional source correlation.