The Application Of Modulation And Demodulation For Shortwave Digital Signal Based On FPGA

Today when satellite communications, mobile communications develop fast , shortwave communications is not only deserted, but develops more fast as the traditional and oldest communication method . It is wildly used in wireless communications area for its advantages of long distance transmission, easily spanned and convenient to move.The way of modulation and demodulation for digital signal is developing fast as one of the important aspects in communication field. All kinds of modern modulation and demodulation technologies are mixed together for the use of technology of all digital signal modulation and demodulation. Now the way of modulation and demodulation for high speed/many methods comes true based on universal DSP. But the speed is low. Universal DSP isn't competent for high speed modulation and demodulation because the restrict of hardware parameter and big operations. But the system of FPGA could provide arithmetic of high speed for multiplication and progression. This paper does some research about the modulation and demodulation based on FPGA technique by using the method of theory combined with practice. By designing and debugging the true system of FPGA, it is to put the theory to practical application.This paper uses a FPGA study board with a chip called EP1C6Q240C8 as the center processor to do some research about the design and exploitation for shortwave digital signal modulation and demodulation. The paper gives different ways of modulation and demodulation. The paper offers us different BER of different ways ,and then analysis the advantages and disadvantages of theirs. At last, the paper focuses on QPSK modulation and demodulation .An circuit about AD/DA is designed to input and...