Design and FPGA realization of all digital FH tracking loop
Quan Houde · Information technology newsletter · 2011
This paper focuses on the application of RF direct sampling in FH-VHF radio set,designs a total-digital FH tracking loop which based on the checking of energy in FPGA hardware circumstance.This design uses the energy accumulation difference which from the lead-lag sub-channes of dehopping local oscillation as reliance to adjusting of phase error,uses variable-two-threshold to improve stability and convergence rate of the tracking loop.The simulation result proves that it can eliminate the phase error between ±0.5Tc(Tc is the characteristics duration time of FH sequence),and realizes stabile dehopping for IF signal.