FREQUENCY OFFSET ESTIMATION DEVICE, FREQUENCY OFFSET ESTIMATION METHOD AND DIGITAL COHERENT RECEIVER

摘要

PROBLEM TO BE SOLVED: To estimate frequency offset without using division.;SOLUTION: A frequency offset estimation unit 14 includes a phase difference calculation unit 23 for calculating a phase rotation amount Δφ of argument θ of a signal corresponding to a continuous symbol, a frequency offset calculation unit 24 for calculating a frequency offset instantaneous value ωs, and a noise removal unit 25 for outputting a frequency offset estimation value ω by removing noise of the frequency offset instantaneous value ωs. The frequency offset calculation unit 24 includes a subtractor 241 for outputting the result d1 of subtraction of a frequency offset estimation value ω in the past from the phase rotation amount Δφ, an adder 242 for outputting the result d2 of the addition of an addition value a2 to the result d1 of subtraction, a bit clear computing unit 243 for outputting the arithmetic result d3 obtained by clearing the lower bits in the first range r2 of the addition result d2, and a subtractor 244 outputting the result obtained by subtracting the arithmetic result d3 from the phase rotation amount Δφ as the frequency offset instantaneous value ωs.;COPYRIGHT: (C)2013,JPO&INPIT