The Research And Design Of Wireless Network Module In The Vehicle Multimedia Information System

The vehicle multimedia information system has many functions such as electron map and the navigation, playing video and music, the security and alarm system, managing the information of car and so on. It has utilized a lot of technologies, for instance, computer technology, automobile electronic technology and multimedia information technology, etc. It has become a hotspot of the automobile electronic industry. Its wireless network module plays an important part in the overall system, the vehicle-carried telephone, the automobile security, the driving monitor, the vehicle dispatch, accessing the Internet, the receiving and dispatching fax, the video and music service and so on, have to be realized through this module.This paper comes from a project, the research of the vehicle multimedia information system, cooperated with a company. The wireless network module is one important part of the project. The module chooses the GPRS technology as its wireless communication platform. It has three main functions: accessing wirelessly the Internet, sending and receiving Chinese and English SMS and the vehicle-carried telephone. The realization of the first one makes the user can load the Internet, upload and download something from the Internet. The second one builds a long-distance connection between the vehicle and the vehicle's owner after the owner left the car. When the car is stolen, the owner can control the car through the SMS and keep the car's security. The last one makes the driver may shift through the call from the mobile phone to the vehicle-carried phone, so that it is convenient for working and driving.This paper has mainly studied the hardware circuit design and the software design of the module. The hardware platform selects the SOPC based on the FPGA, in which the Nios II processor is embedded. GPRS hardware circuit also is designed. When developing the software, it has two steps. At first, the communication between the GPRS module and the computer has been tested and researched and the module's function has been realized by VC program. Then, the software is designed on the embedded hardware platform. These designs include serial port driver, G20 module initialization, the alarm by SMS, the vehicle-carried telephone and accessing wirelessly Internet.Finally, the paper gives a conclusion, and point out some unsolved problem and the further research direction.