| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an FSK demodulation circuit capable of restoring correct data always independently of a lower local or an upper local frequency conversion system. <P>SOLUTION: A correlation value COR between the demodulated data DT acquired by demodulating intermediate frequency signals IN modulated in a FSK manner and every bit of synchronization words is formed. Half the number of bits of the synchronization words are subtracted from the correlation value COR; the sign SIG and absolute value ABS of the remainder SUB of the above subtraction are obtained, and when it is found that the absolute value ABS is larger than a threshold value TH, the sign SIG is held, and the absolute value is made to serve as judgment signals JDG. An exclusive OR of the demodulated data DT and judgement signals JDG is output as reception data RD. <P>COPYRIGHT: (C)2008,JPO&INPIT |
