Rate Distortion Performance for Joint Source Channel Coding of JPEG Image Over AWGN Channel

s v national institute of tech. surat,395007,india This paper presents the rate distortion behavior of Joint Source Channel Coding (JSCC) scheme for still image transmission. The focus is on DCT based source coding JPEG, Rate Compatible Punctured Convolution Codes (RCPC) for transmission over Additive White Gaussian Noise (AWGN) channel under the constraint of fixed transmission bandwidth. Information transmission has a tradeoff between compression ratio and received quality of image. The compressed stream is more susceptible to channel errors, thus error control coding techniques are used along with images to minimize the effect of channel errors. But there is a clear tradeoff between channel coding redundancies versus source quality with constant channel bit rate. This paper proposes JSCC scheme based on Unequal Error Protection (UEP) for robust image transmission. With the conventional error control coding schemes that uses Equal Error Protection (EEP), all the information bits are equally protected. The use of the UEP schemes provides a varying amount of error protection according to the importance of the data. The received image quality can be improved using UEP compared to Equal Error Protection (EEP)