A Wireless Video Transmission System Based On CDMA 1X And The Research On Error Control Techniques

With the development of modern communication technology, the requirements of communication services have turned from single sound to video and audio, the multimedia communications become one of the hotspots in the communication fields. Meanwhile, as wireless communication technology progresses increasingly in recent years, people aren't satisfied with enjoying video service merely in the conventional LAN, wireless and mobile requirements put forward higher demand for the video communication.This paper designs and realizes a wireless video transmission system based on CDMA 1X. Firstly, it introduces the basis of video communication, places emphasis on the relative techniques of video transmission. Afterwards, it presents concrete implement methods of the system, including capturing module, coding module, transmission module and decoding module, takes a detailed discussion on the design of PPP connection, RTP encapsulation, socket communication in the transmission module, enumerates some key data structures and function prototypes of the system.In order to solve the transmitting errors, this paper studies the error control techniques of wireless video transmission based on the CDMA 1X. Firstly, this paper introduces some general methods. And then, it presents INTRA refresh based on feedback, inserting re-synchronous markers, using Sequence Number field of RTP, which are suitable to the channel character of CDMA 1X. Experiment results of the method are presented.Finally, this paper gives a whole systematic test on some important parameters in the conditions of different error control strategies, including transmission bit rate, end-to-end delay, picture quality and codec speed.