The Research And Realization Of High-Speed Modulate And Demodulate System In Narrow Band Based On FPGA

Because of the reduction by a large margin of quantity of users , such as beeper , interphone ,etc, the frequency resources (UHF) they occupied have got a large amount of release, how to utilize the frequency resource again, it will be a very hot topic of future.This subject is mainly about a high-speed modulate and demodulate technologyused in channel of 400MHz frequency and 25KHz band-QAM modulate anddemodulate technology, discussion the principle of QAM modulation and realizing(Mainly include the adaptive equalizer algorithm and carrier recovery algorithm),and simulate the whole system in the Matlab software's simulink tool box.At last, to realize the whole system with FPGA.In the course of the realization ,1 choose the chip of Xc3s400,a kind of FPGA chip of Xinlinx ,and under the integrated development environment of ISE6.2i ,1 realize the main part of the whole system with the VHDL language ,and finished the behavior simulation and the synthesis. Finally, validate the whole system on my own hardware .The main content of the paper as follow:1. Expatiate the important theory and algorithm related to this paper Channel model and important parameter analysis Basic theory of QAM modulation and the introduction of the import parameter of performance of the modulation Basic theory of the LMS(Least Mean Square) algorithm adaptive equalizer Basic theory of the digital Costas loop2. Design the whole system and simulate the system project on Simulink ,At the time ,analysis the result of the system simulation3. The realization of the whole system and the choice of the important parameters Hardware realization project Software realization project of the important models...