Implementation of DS/FH communication intermediate frequency π/4 DQPSK modulation based on FPGA
Huang Guo-qing, Qiao Tian-xi · 2011
DS/FH communication intermediate frequency modulation module is designed based on FPGA, the module can be used in the hopping frequency system with the band of 200MHz, hopping speed of 1000hop/s. It can meet the intermediate frequency π/4 DQPSK modulation requirement. The performance of QPSK, π/4 DQPSK and π/2 DQPSK modulating is compared by MATLAB simulation, The simulation results show that the performance of π/4 DQPSK modulation format is optimization. And the principles, FPGA design, key technique in FPGA and hardware realization of the π/4 DQPSK modulation are given. The modulation rate of the designed intermediate frequency π/4 DQPSK modulation module reaches 2.5 Mbit/s on 10MHz clock rate, the modulating signal can demodulate with 0.025 low error rate in the signal-to-noise ratio -15dB interference environment.