Technology Of CDMA2000 Baseband Signal Processing And Its DSP Implementation

Recently,with the development of communication technology, there are three main technical standards such as CDMA2000, WCDMA and TD-SCDMA for the third generation mobile communication systems by which people can get a very high quality and convenient service in their daily life. However, because of the complexity of mobile communication system, it is difficult for people to grasp the various technical standards in the protocol.Faced with the arrival of the information age, people enjoy the pleasure of the information society at the same time, also encountered a new challenge.It is very necessary to learn and master the CDMA mobile communication technology for the vast numbers of engineers and college students.This paper is based on a lot of literatures and relative design schemes. According to the principle of CDMA2000, a CDMA2000 baseband signal processing module based on DSP has been designed mainly for the library of high school and other related institute. The union of DSP and CPLD is the main controller system, and the CDMA2000 channel physical layer protocol is the theoretical basis,and the experiments are carried out in accordance with the design of signal processing flow. The design and development of most part of basic experiment of baseband signal processing in CDMA2000 physical layer channel can be completed on the module. This experimental system is made up of two parts, hardware and software. The hardware includes power supply module, DSP central processing unit module, CPLD module, AD module, DA module, Flash module and so on. And the software includes CRC coding, convolutional coding, block interleaving, Walsh coding, long code spreading spectrum, short code scrambling and QPSK modulation and so on.This experimental module has been put into use now. Compared with other communication experimental platforms, the versatility and openness have been enhanced.There is no need for the user to change the hardware circuit, the research of algorithm and the expansion of the experiment will be able to achieve as long as by modifying the software.The operation is simple and convenient.