Signal processing circuit and communication device having the same

A signal processing circuit for reducing a peak-to-average power ratio of a modulated wave signal to be inputted to a power amplification circuit, the signal processing circuit comprising:

• a power calculation section that calculates an instantaneous power of an IQ baseband signal of the modulated wave signal;
• a pulse generation section that generates, by using a plurality of basic pulses determined for respective frequency bands of the IQ baseband signal, one cancellation signal capable of canceling the IQ baseband signal in accordance with an average power for each frequency band;
• a signal processing section that limits, by using the cancellation signal, an amplitude of the IQ baseband signal so as to cause an upper limit or a lower limit, or both of the upper limit and the lower limit of the instantaneous power to be equivalent to a corresponding predetermined threshold(s),
• wherein each of the basic pulses has a waveform mathematically expressed by the following equation (1) which has symmetry in a time domain:
• y
• =
• f
• ⁡
• (
• x
• )
• =
• ∏
• n
• =
• 1
• ⁢
• ⁢
• [
• 1
• -
• (
• x
• a
• n
• )
• 2
• ]
• (
• 1
• )
• in a case of Sinc, an=nπ.