Ressearch Of Joint Source-Channel Coding Based On H.264 And Rate-compatible Punctured Turbo Coding

Recently, with the rapid development of technologies such as computer, communication and network etc.,there is an increasing demand for multimedia service. Wireless video transmission, as an essential component ofwireless multimedia, has been widely appreciated. Traditional communication systems are based on the separationtheorem of Shannon, source coding and channel coding are separated, this separation of design methods often leadto low efficiency of video transmission applications, while the Joint Source-Channel coding can achieve betterperformance gain. Unequal error protection is an important branch of the Joint source-channel coding, which iswidely used in the real-world systems. In the video transmission system, the importance of data bits transmissionis usually different. Using different channel protection schemes on different parts of the bit stream after sourcecoding to improve overall system performance is necessary under limited resource system. Therefore, the researchof Joint Source-Channel coding is of great practical significance.In this thesis, I present a Joint source-channel coding scheme to transmit compressed video bits over wirelessfading channel, which is based on H.264 and RCPT. The proposed scheme is based on unequal error protection.Firstly, this paper gives a brief overview about the Joint Source-Channel coding and introduces the background,basic theory and common methods of it. Secondly, the thesis takes a more in-depth research of the H.264 videocoding methods and analyzes the key technology used in H.264, and then uses the JM86 to simulate the videosequence of testparis, so as to verify the importance of the source data level. Thirdly , I study the encoding anddecoding principles of Turbo codes and RCPT codes in details, and the key factors which affecting theirperformance, then complete the simulation by using the Simulink of MATLAB. Finally, the paper presents a Jointsource-channel coding scheme based on the unequal error protection, which is combined with the characteristic ofH.264 source codes and RCPT channel codes. In the proposed system, RCPT codes provide unequal errorprotection for the H.264 data bits according to its error sensitiveness. Then I comes up with using the channel stateinformation immediately to adjust the encoder parameters (such as the quantization coefficient and the videoframe rate) to adapt to channel conditions, resulting in the allocation of the appropriate rate in channel coding andsource coding, so that the entire system for optimal performance. The simulation results show that the proposedUEP scheme obtains a superior performance and higher reliability, which can significantly improve videotransmission quality.