RADIO COMMUNICATION APPARATUS AND DC OFFSET ADJUSTMENT METHOD
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Accused Products
Abstract
At a transmitting side, during carrier leak adjustment, quadrature modulation means uses a carrier wave having a frequency different from that at a receiving side to quadrature-modulate an outgoing signal. Feedback means feeds a modulated wave resulting from the quadrature modulation back to the receiving side. At the receiving side, quadrature demodulation means quadrature-demodulates the fed back modulated wave. Phase locking means locks the phase of the signal resulting from the quadrature demodulation to match the phase to the phase at the transmitting side. Offset detection means time-averages the phase-locked signal to detect a direct-current offset. At the transmitting side, based on the value of the direct-current offset detected at the receiving side, offset adjustment means corrects a direct-current offset of the outgoing signal to be quadrature-modulated.
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Citations
28 Claims
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1-15. -15. (canceled)
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16. A radio communication apparatus comprising:
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a quadrature modulator that quadrature-modulates an outgoing signal by using a carrier wave having a frequency different from a frequency at a receiving side during carrier leak adjustment; a feedback unit that feeds a modulated wave resulting from the quadrature modulation by the quadrature modulator back to the receiving side; a quadrature demodulator that quadrature-demodulates the modulated wave fed back by the feedback unit; a phase locker that locks a phase of a signal resulting from the quadrature demodulation by the quadrature demodulator to match the phase to a phase at the transmitting side; an offset detector that detects a direct-current offset by time-averaging the signal with a phase locked by the phase locker; a first offset adjuster that, on the basis of the value of the direct-current offset detected by the offset detector, corrects a direct-current offset of the outgoing signal to be quadrature-modulated by the quadrature modulator; a third offset adjustor that corrects a direct-current offset of the signal on the basis of a value of a direct-current offset detected in the signal with the phase locked by the phase locker; a pattern generator that generates a predetermined pattern to be input into the direct-current modulator during carrier leak adjustment; and a pattern detector that detects the pattern in a signal in which a direct-current offset has been corrected by the third offset adjuster to determine a carrier recovery phase. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A direct-current offset adjustment method for adjusting a direct-current offset within an apparatus, comprising:
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at a transmitting side, quadrature-modulating an outgoing signal by using a carrier wave having a frequency different from a frequency at an receiving side during carrier leak adjustment; and feeding a modulated wave resulting from the quadrature modulation back to the receiving side; at the receiving side, quadrature-demodulating the fed back modulated wave; locking a phase of a signal resulting from the quadrature demodulation to match the phase of the signal to a phase at the transmitting side; and detecting a direct-current offset by time-averaging the phase locked signal; and at the transmitting side, correcting, on the basis of the value of the direct-current offset detected at the receiving side, a direct-current offset of the outgoing signal to be quadrature-modulated; wherein, at the transmitting side, a predetermined pattern is generated and used in the outgoing signal; at the receiving side, the direct-current offset detected in the phase-locked signal is notified to the transmitting side and a direct-current offset of the signal is corrected on the basis of the direct-current offset; and the pattern is detected in the signal in which the direct-current offset has been corrected to determine a carrier recovery phase. - View Dependent Claims (24, 25, 26, 27, 28)
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Specification