Research On QPSK Digital Demodulation Techniques Based On FPGA

Wireless communication is a corresponding mode which making electromagnetic waves transmitted in free space to send and receive information; the method has a long history over 150 years. From the original simple character to the speech signal, up to today's image signal, wireless communication technologies are being required higher and higher.A complete communication system should be composed of two parts --- the transmitter and the receiver. Thus, the core issue of a communication system design is the development of the transmitter and the receiver. This thesis is based on software radio technology, also refers to digital communication system, digital signal processing technology and EDA technology. a new type of receiver baseband demodulation system of design. ccording to system demand, in the System view on the structures in the FPGA hardware and the specific algorithm to implement a complete simulation of operations, designed to meet the system demand of the QPSK demodulation hardware electric circuit.In the EDA platform of QuartusⅡ, writing VHDL design language, through an integrated, adaptive and simulation, and finally reached the core device module simulation waveform. downloaded in the FPGA and debugthe hardware circuit. At last demodulate a QPSK signal with a carrier frequency of 48MHZ, and with a bandwidth of 4MHZ.