Patent ID: 7496333
Filing Date: 2009-02-24
Classification: H04L

Abstract:
1. A transmission circuit for generating and outputting a transmission signal based on input data, comprising: a signal generating section for modulating the input data to generate data in a predetermined format; a computation section for computing the data generated by the signal generating section to output an amplitude signal, a first phase signal, and a second phase signal; a regulator for outputting a signal controlled depending on the amplitude signal; a first angle modulation section for angle-modulating the first phase signal and outputting the result as a first angle-modulated signal; a first amplitude modulation section for amplitude-modulating the first angle-modulated signal using the signal output from the regulator, and outputting the resultant angle-modulated and amplitude-modulated signal as a first modulated signal; a second angle modulation section for angle-modulating the second phase signal, and outputting the result as a second angle-modulated signal; a second amplitude modulation section for amplitude-modulating the second angle-modulated signal using the signal output from the regulator, and outputting the resultant angle-modulated and amplitude-modulated signal as a second modulated signal; and a combining section for combining the first modulated signal and the second modulated signal and outputting the result as the transmission signal, wherein the computation section calculates an amplitude component and a phase component of the data generated by the signal generating section, compares a magnitude of the amplitude component with a predetermined amplitude threshold value, and if the magnitude of the amplitude component is larger than the predetermined amplitude threshold value, outputs an amplitude signal obtained by multiplying the magnitude of the amplitude component by a predetermined constant, the first phase signal corresponding to the phase component, and the second phase signal corresponding to the phase component, and if the magnitude of the amplitude component is smaller than the predetermined amplitude threshold value, outputs an amplitude signal obtained by multiplying the predetermined amplitude threshold value by a predetermined constant, a first phase signal obtained by shifting the phase component by a predetermined phase in one direction, and a second phase signal obtained by shifting the phase component by a predetermined phase in another direction.