Research & DSP Implementation Of Demodulation Module Based On The CDMA2000 Forward Link

The information industry department awarded the third generation mobile communications (3G) licenses to operators on January 7.2009, means china is official to enter the age of 3G. CDMA2000 license was awarded to China Telecom; TD-SCDMA license was awarded to China Mobile Communication, WCDMA license was awarded to China Unicom Communication. At present, CDMA2000 has the most users and the technology is also the most mature. CDMA2000 standard is instituted by 3GPP2 organization, the standard made the evolution of CDMA IS95(2G)-CDMA20001x-CDMA20003x(3G), from the existing CDMA20001x structure directly into the 3G, construction costs are low. At present, China Telecom use the scheme to transition and 3G networks have been built in the CDMA IS95. During 3G networks with a large number of construction and 3G cell phones with a wide application, network optimization will be the important goal after networks construction, therefore, cdma2000 scanner will have a wide application prospect in 3G networks optimization and have a significant commercial value.The responsibility of this paper is the research and realization of the demodulation module in CDMA2000 scanner. According to the cdma2000 standards instituted by 3GPP2 organization, this paper research the construction and demodulation process of uplink physical channels, realize the demodulation of physical channels, and successfully develop the cdma2000 scanner. The demodulation module constitutes three parts: demodulation of pilot channel,synchronous channels and paging channel.This paper introduces the related technology of CDMA2000, the key is the principle of spread spectrum of communications; then introduces the modulation technology; based on the structure and modulation process of pilot channel,synchronous channels and paging channel, make the design of the three channel's demodulation method and flow; then make the simulation of the demodulation module's algorithm by matlab; at last, implement the algorithm by DSP(Texas instruments company) and verify the algorithm .