Patent ID: 8285508
Filing Date: 2012-10-09
Classification: H04L

Abstract:
1. A signal processing apparatus comprising: a test signal generation unit that generates a first test signal set including first and second test signals, each of the first and second test signals comprising an in-phase component and a quadrature component, the first and second test signals having a predetermined phase relationship therebetween, the test signal generation unit supplying the first test signal and the second test signal of the first test signal set to an orthogonal modulator in this stated order, the test signal generation unit generating a second test signal set including first and second test signals, each of the first and second test signals comprising an in-phase component and a quadrature component, and supplying the first test signal and the second test signal of the second test signal set to the orthogonal modulator in this stated order, the in-phase and quadrature components of the first and second test signals of the second test signal set respectively having predetermined relationships with the in-phase and quadrature components of the first and second test signals of the first test signal set; a detector that receives an output of the orthogonal modulator and detects an envelope of the output of the orthogonal modulator; a comparison unit that compares detection results by the detector detecting orthogonal modulation outputs of the first and second test signals by the orthogonal modulator; a control unit that derives first and second adjustment values respectively from detection results of outputs produced by the orthogonal modulator responsive to inputs of the first and second test signals of the first signal set and from detection results of outputs produced by the orthogonal modulator responsive to inputs of the first and second test signals of the second test signal set, the control unit obtaining the first adjustment value, based on a result of comparison of the detection results of the orthogonal modulation outputs of the first and second test signals of the first test signal set, the control unit obtaining the second adjustment value, based on a result of comparison of the detection results of the orthogonal modulation outputs of the first and second test signals of the second test signal set; and a compensation value derivation unit that derives the compensation value for compensating for at least one of the DC offset, an IQ amplitude mismatch, and an IQ phase mismatch of the orthogonal modulator from the first and second adjustment values respectively obtained by the control unit for the first and second test signal sets.