Wireless Video Transmission System Is Developed

Future wireless applications,such as video cellular telephony,wireless Internet access and wireless LANs,have open a new field for wireless multimedia communication -image communication,which push a growing demand for fast,economic,low-energy mobile multimedia communication. However,there are still several bottlenecks -bandwidth,low-delay,power and noise etc,need to be solved. They make image coding and wireless transmit technologies to be hot research points. In this thesis,we made theory analysis on image communication,including video capture,source coding,modulation,and communication protocol. A simple,fast,effective and economic wireless image communication system is proposed and it is implemented successfully on IEEE802.11b wireless LANs based on VC++ programming and ORINOCO network card.We use PHILIP PCV616CA Camera as video capture device. It is a standard USB PC camera with CCD sensors. Its sampling rate can reach up to 30 frames per second when using QCIF format,while 15 frames per second can be obtained for CIF format. We also use AVICap multimedia interface provided by VC++ for Windows to make software for capturing video on time. To overcome limited bandwidth and reduce data size,the raw image data source from camera is coded with simple,effective Motion-JPEG algorithm. We also use Matlab to simulink effects on which some compression parameters such as VBS and Quantization level have.CCK,DQPSK are concluded as the best spread spectrum/modulation techniques in wireless image communication systems. 1 IMbps and 300 meter range can be obtained using ORINOCO wireless network card based on EEE802.11b WLANs,which specifies CCK,DBPSK,DQPSK techniques. Stream socket programming is also studied in this thesis to support the software implementation of proposed wireless image communication system.The thesis is organized as follows:an overview of wireless and multimedia communication is presented and a wireless image communication system is proposed in chapter 1;Chapter 2 makes a brief introduction on image signal capture device and related software implementation;Source coding is mainly studied in chapter 3,followed by in-depth modulation techniques studies in chapter 4. Chapter 5 presents socket programming principles and implements the whole proposed system. Inchapter 6,we give the conclusions and propose the future work.