| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit of demodulation circuit integration for correcting a carrier frequency error in small-scale circuit constitution in the reception of a communication system adopting a frequency modulation system and a phase modulation system. <P>SOLUTION: A demodulation circuit comprising a PLL demodulator 41 for demodulating frequency modulation signals, a frequency error detection part 42 for detecting the carrier frequency error from PLL demodulator output, a first judgement part 44 for outputting first baseband signals by judging the data of the PLL demodulator output using the detection result of the carrier frequency error as a threshold, a phase demodulator 54 for demodulating phase modulation signals, a correction part 49 for correcting the phase demodulator output by using the detection result and a second judgement part 50 for judging the data of the output signals of the correction part and outputting second baseband signals is integrated on a semiconductor substrate. One of the first and second baseband signals is selected and sent to a baseband processing part 52. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
