Design Of Image Capture And Wireless Communication System Based On XScale And Linux

In recently, with the fast development at computer, network, image process,communication and transmission technology,digital image acquisition system is now developed in the direction of embedded miniaturized and network system. Meanwhile, embedded system develops rapidly and it is applied more widely,and that because Linux system is a steady, safe and low-cost operation system,more and more enterprises and users take Linux as the server's chief operating system.Furthermore,CDMA 1X network becomes the important resource in modern communication technology information area. Thus, we propose and design a video image capture and wireless communication system under Linux system based on CDMA 1X network.Firstly, this thesis investigates the development and research of world's video capture and wireless communication technology,and introduces the development of embedded micro processor and operating system,then the thesis presents a design scheme, which is composed of XScale micro processor and embedded operating system Linux, and then sets up Arm-Linux cross development environment,and customizes the minimum Linux kernel that we need.Subsequently, the key technology of video capture in using USB camera under Linux system are discussed. Compression of digital image is the precondition for the miniaturization of digital image acquisition system. This thesis analyzes the video technology and interrelated compression theory, selects JPEG (Joint Picture Experts Group) compression technique for this system, and discusses in detail about how to develop the hardware and the software of system, including hardware frame of USB video capture, loading drive and V4L module, video capturing and compression in C program language and software transplant.Followingly, the wireless communication system in Linux system is discussed and designed.Furthermore detailedly discussing CDMA 1X network technology,contrastively analyzing CDMA 1X and GPRS (General Packet Radio Service), providing the reason of selecting CDMA 1X network.Then this thesis marks out the hardware design of the communication system terminal,introduces the principle of PPP (Point-to-Point) Protocol, and the working flow of wireless access Internet based on CDMA 1X.Lastly, the thesis discusses the research and realization of network transmitting, introduces the Linux network hiberarchy,TCP/IP protocol,Socket programming and basic API function.And then the application software realization scheme is presented about the video compression data transmitting and monitoring center.