| 摘要 |
PURPOSE: A PAR(Peak to Average Ratio) reducing apparatus for multicarrier transmitter is provided to use a low power amplifier by reducing a PAR of transmission power at a CDMA multicarrier transmitter. CONSTITUTION: The first and second multipliers(110,111) spread signals of each channel with a spread code. Interpolators(120,121) interpolate outputs of the first and second multipliers(110,111). A maximum value restriction signal generator(130) detects a maximum signal of each channel signal and generates a maximum value restriction signal. First and second delay units(140,141) delay outputs of the interpolators(120,121) and the maximum value restriction signal generator(130) to synchronize them. The first and second subtractors(150,151) subtract maximum values of each channel signal outputted from the first and second delay units(140,141) by the maximum value restriction signal and output them. The third and fourth multipliers(160,161) multiply different carrier frequencies to each output signal of the first and second subtractors(150,151). An accumulating/adding unit(170) accumulates outputs of the third and fourth multipliers(160,161) and adds them. A digital/analog converter(180) converts an output of the accumulating/adding unit(170) into an analog signal. A frequency up-converter(190) converts the analog signal to a radio frequency. A radio frequency amplifier(200) amplifies an output of the frequency up-converter(190) and radiates it through an antenna(210). |
