The Application of Rate Compatible Punctured Convolutional Codes in Wireless Mobile Videophone Systems

• Main Authors: Wu mei-ying, 吳玫嬴
• Other Authors: 劉玉蓀
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/68474204141021295941

碩士 === 中原大學 === 電機工程研究所 === 86 === In this paper, a flexible and adaptive videophone scheme is proposed for GSM system. The mobile radio channel is time varying and has fading effects that cause errors during data transmission.Consequently,error control schemes are needed. We adopt a dynamic coding strategy,to change both the image data rate and code rate, and hence the error correction power during transmission of an image frame is according to channel conditions. Rate-compatible punctured convolutional codes (RCPC codes) are chosen to achieve finely-graded error protections because different code rate can codec within just one encoder/decoder.Besides, interleaving is employed to increase the error correction capability of RCPC codes.To improve the reliability and throughput of the system, we use typeⅡ hybrid ARQ scheme with code combining. Based on simulation results, it is shown that our proposed videophone scheme is suitable for GSM system.