| 摘要 |
PURPOSE: A device of transmitting fast data in a mobile communication base station system is provided to output a normal QAM(Quadrature Amplitude Modulation) signal through a high power amplifier by using a previously-distorted OAM symbol, thereby preventing distortion of transmission data, reduction in an average data rate, and deterioration of speech quality. CONSTITUTION: An error correction code unit(110) corrects an error of transmission data. An adaptive QAM modulator(120) stores a previously-distorted QAM symbol in an opposite direction to nonlinear characteristics of a high power amplifier(140), and maps transmission data inputted from the error correction code unit(110) with the previously-distorted QAM symbol, then performs a QAM modulation. A CDMA modulator(130) inputs a QAM signal from the adaptive QAM modulator(120), and multiplies a PN code to carry out a band-spreading process. The high power amplifier(140) inputs the QAM signal from the CDMA modulator(130), and amplifies the QAM signal at high power level.
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