Cdma Terminal Rf Receiver Front-end Design

The research of wireless mobile communication technology has become more and more important at home and abroad .The technology has experienced first and second generation of development. And now the third generation has already been applied in commercial operations. With its unique advantages, the technology of CDMA is widely used in 3G system whose three main kinds of standards are TD-SCDMA, WCDMA, and CDMA2000. The CDMA cellular systems have provided voice and data communications for the public as well as a broad space of application for the terminals based on CDMA, such as positioning terminals and monitoring terminals. To achieve functions the terminal can not do without a good RF front-end of CDMA receiver which suggests a greater challenge.In this paper, the RF front-end of a dual-channel CDMA terminal was designed and implemented. The terminal could receive information both from the user terminal and the base station to position or monitor the user terminal after processing the information. The modular design made the RF front-end be relatively independent from other parts of the terminal, which thus met a wide range of applications simply by changing the approach of processing digital data in its base-band. With the increased flexibility the application scope of the CDMA terminal had been expanded.Experimental results showed that the RF front-end had met the requirements of the terminal. And the terminal had already been on trial. Lastly, interferences caused by the leakage in LO were detailed analyzed and tested in the terminal. And effective solutions were proposed. The concluding laws may bring great reference values to the design of the receiver.