The Research And Design Of Digital Intermediate Frequency System Of TD-SCDMA Repeater Based On Software Radio

At present, The third generation mobile communication systems (3G) is widely used.TD-SCDMA technology as our R&D technology has been concerned by its simple hardware andso on.Repeater is an effective and convenient network optimization product. With the same effect,it costs less than micro-cellular; Software radio technolog as its versatility and openness iswidely used in the repeater. Compared with the traditional analog receivers, the digital radioreceiver based on the software radio technology is programmable and flexible for deployment,etc. TD-SCDMA repeater based on software radio has become a hot research.For TD-SCDMA technology, uplink and downlink information can be transmitted in thesame carrier frequency and different time slots. The time slot is used to distinguish differentusers in the time domain, thus confirming the time slot switching point is the key of repeaterdesign. The TD-SCDMA repeater based on software radio needs to determine the time slotbetween uplink and downlink firstly, and then do radio-frequency amplification. At present, thedesign method of sampling RF signals directly is difficult achieve for the reason of devicerestrictions, so the conversion from RF signals to baseband signals is needed.This thesis is based on these theories, which use digital IF technology of the software radioto convert the RF signal into an analog IF signal and consequently do IF sampling and digitaldownconversion processing, Base-band IQ signals are output into FPGA at last. This thesisdescribes the research and design of digital IF system of TD-SCDMA repeater based onsoftware radio, which includes the technology of TD-SCDMA repeater related, digital IF theory,TD-SCDMA wireless repeater design structure, the design and simulation of digitaldown-conversion system by MATLAB and Quartus II , the circuit design of IF processingmodule, LNA, PA and so on by Cadence.