Title: Transmitter apparatus and wireless communication apparatus
Application Number: 200580006425 Application Date: 2005.02.25
Publication Number: 1926770 Publication Date: 2007.03.07
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H04B1/04;H03C7/02;H03F1/02;H03F1/32;H03G3/10
Applicant(s) Name: Matsushita Electric Ind Co., Ltd. Address:
Inventor(s) Name:
Attorney & Agent: huangxiao lin wangzhi sen
Abstract:
    A transmitter apparatus capable of performing a high-efficiency polar coordinate modulation, while maintaining a good distortion characteristic. In the case of causing a large power amplifier (13) to operate in a saturation mode to perform a polar coordinate modulation, a switch control signal to be inputted to a multiplication/division switch terminal (33) is set to multiplication, whereby a distortion compensating part (17) multiplies quadrature modulated digital signals from I and Q input terminals (31,32) by distortion data from a compensation table (16), thereby adding a nonlinear distortion, which is equivalent to that during use of the large power amplifier (13) in a linear mode, to compress the peak factor of the modulated signals, thereby enhancing the efficiency of the polar coordinate modulation. In the case of causing the large power amplifier (13) to operate in a linear mode to perform a linear amplification, the switch control signal is set to division, whereby the distortion compensating part (17) divides the quadrature modulated digital signals by the distortion data, thereby adding a reverse distortion characteristic of the large power amplifier (13) to perform a nonlinear distortion compensation of the large power amplifier (13).
Time: 9
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