| 摘要 |
<P>PROBLEM TO BE SOLVED: To separate and correct a quadrature error of a quadrature modulator, and a quadrature error of a quadrature demodulator by a simple calculation. <P>SOLUTION: A quadrature error detection part 320 detects a quadrature error of a quadrature modulation part 140, and a quadrature error of a quadrature demodulation part 230 based on an amplitude of a demodulation signal. Specifically, in the quadrature error detection part 320, de-multiplexers 321 and 322 separate the demodulation signal into a signal arranged on an I-axis at the time of transmission and a signal arranged on a Q-axis at the time of transmission in accordance with a signal-point-arrangement on an IQ plane at the time of transmission. Zero cross detection parts 325 and 326 detect amplitudes of intersections at which the separated signals and the I-axis and the Q-axis intersect. The quadrature error detection part 320 detects the quadrature errors based on comparison results of the amplitudes of the intersections. A gain control part 330 controls setting values of a transmission quadrature error correction part 120 and a receiving quadrature error correction part 250 in accordance with the detection results of the quadrature errors. <P>COPYRIGHT: (C)2012,JPO&INPIT |
