The Design And Implement Of The Spread Spectrum Communication System Based On STEL-2000A

With the swift development of mobile communication,the ITU advances the standard of IMT2000 as the target of the 3^rd generation mobile communication system. And the most influencing and applicative communicational technologies based on CDMA are WCDMA, cdma2000, and TD-SCDMA. And then the technology of CDMA based on spread spectrum theory plays a very important role in the mobile communicational technology, which indicates the use of of spread spectrum communication technique in the commercial field has developed into a new stage.Under this background,a lot of famous LSI (Large Scale Integration of Circuits) manufacturer in the world has developed their own spread spectrum chip products which have a lot of functions.Their appearances provide the application of the spread spectrum communication system a more convenient platform.Based on studying and reading a lot of relative literatures,this paper designs and realizes a direct sequence spread spectrum communication baseband system depend on Stanford Telecom corporation's new spread spectrum chip STEL-2000A and Intelcorporation's AT89C51. This project analyses and expatiates the interior configuration and working principle of STEL-2000A, and emphasizes on the important blocks and pivotal techniques in the chip.Then it designs the scheme of the spread spectrum system,including the holistic frame of the system and the choices of crucial parameters.The design of this scheme adopts ASIC chip to fulfill the main functions of the spread spectrum communication system and can be controlled by software.The circuit is simple and flexible.This design can fulfil the demands of different data transmission speed. It accomplishes the design of hardware circuit,and expatiates the capability of every chips in this system and the periphery interface circuit between these chips. After analysing and predominating the controlling timing of the chip and the working principle of the system,this paper designs the system software including the main programme block.the transmission controling block and the receiving controlling block.And it emphasizes on how to set the inner registers of STEL-2000A.At last,debugging is done on the hardware platform,and the correct waveform results havebeen gained.Through the design and debugging of software and hardware,the comprehension of the improtant blocks and pivotal techniques in the spread spectrum communication system has become deeper.And some useful results have been acquired.Practical experiences have been accumulated for the development of spread spectrum chip of our country own.