Compensation apparatus, signal generator and wireless communication equipment

摘要

A compensation apparatus compensates a quadrature-demodulated signal output from a quadrature demodulator 5 that performs quadrature demodulation by using a signal of a carrier frequency fc, by removing an image component caused by the quadrature demodulator 5 from the quadrature-demodulated signal. The compensation apparatus includes a signal generator 10 that generates a reference signal having a predetermined bandwidth in a reception band, and provides the reference signal to an input side of the quadrature demodulator 5. The reference signal includes a frequency band that is biased to either a higher-frequency side or a lower-frequency side with respect to the carrier frequency.

主权项

1. A compensation apparatus which compensates a quadrature-demodulated signal output from a quadrature demodulator that performs quadrature demodulation by using a signal of a carrier frequency, by removing an image component caused by the quadrature demodulator from the quadrature-demodulated signal, the compensation apparatus comprising:
a signal generator that generates a reference signal having a predetermined bandwidth in a reception band, and gives the reference signal to an input side of the quadrature demodulator; a calculation section that calculates a compensation parameter for rejecting the image component, based on a signal obtained by quadrature-demodulating the reference signal with the quadrature demodulator; and an image component rejection section that rejects the image component from the quadrature-demodulated signal based on the compensation parameter, wherein the reference signal includes a frequency band that is biased to either a higher-frequency side or a lower-frequency side with respect to the carrier frequency, and the calculation section
generates, as a reference signal replica, a signal on which the image component in the frequency domain is not superimposed, the signal being a part of the signal obtained by quadrature-demodulating the reference signal and output from the quadrature demodulator, andcalculates the compensation parameter, based on a signal for calculation that includes the reference signal replica and an image component caused by the reference signal replica, and on the reference signal replica being a part of the signal obtained by quadrature-demodulating the reference signal.