QPSK modulation and demodulation system design and simulation based on VHDL

This paper introduces the working principle of QPSK technology,and introduces the QPSK modulation and demodulation system design scheme。 Write modulation and demodulation program with VHDL language,and simulate through the QuartusII modeling software,and download the program to FPGA chip EP1K30TC144-3 through the pin locking。 The software simulation and hardware verification results that the validity and feasibility of the design。 Since using FPGA chip,which can reduce the hardware design complexity,this design can be transplanted,maintained and upgraded very easy.