Patent ID: 8164322
Filing Date: 2012-04-24
Classification: H04L

Abstract:
1. A phase-difference-corresponding-value measurement device which receives a demodulated signal from a quadrature demodulator for receiving a modulated signal output by a quadrature modulator, and applying quadrature demodulation to the received signal, and measures a phase-difference corresponding value corresponding to a phase difference between an I component and a Q component of the modulated signal, wherein the quadrature modulator applies the quadrature modulation to an original I signal and an original Q signal having frequencies different from each other, the frequency of the original I signal is referred to as I frequency, a frequency obtained by inverting the sign of the frequency of the original I signal is referred to as opposite-sign I frequency, the frequency of the original Q signal is referred to as Q frequency, a frequency obtained by inverting the sign of the frequency of the original Q signal is referred to as opposite-sign Q frequency, the phase-difference-corresponding-value measurement device comprising: an I-frequency-phase deriving unit that derives the phase of a component of the I frequency of the demodulated signal; an opposite-sign I-frequency-phase deriving unit that derives the phase of a component of the opposite-sign I frequency of the demodulated signal; a Q-frequency-phase deriving unit that derives the phase of a component of the Q frequency of the demodulated signal; an opposite-sign Q-frequency-phase deriving unit that derives the phase of a component of the opposite-sign Q frequency of the demodulated signal; a first phase-difference-corresponding-value deriving unit that derives a first phase-difference corresponding value corresponding to a difference between the derived result of the I-frequency-phase deriving unit and the derived result of the Q-frequency-phase deriving unit; a second phase-difference-corresponding-value deriving unit that derives a second phase-difference corresponding value corresponding to a difference between the derived result of the opposite-sign I-frequency-phase deriving unit and the derived result of the opposite-sign Q-frequency-phase deriving unit; and an averaging unit that derives the phase-difference corresponding value based on an average of the first phase-difference corresponding value and the second phase-difference corresponding value.