Rds demodulator for the reception of broadcast radio programs the radio data signals and car drivers round radio information signals (ari), using a digital filter device which a high attenuation of the ari signal

摘要

PROBLEM TO BE SOLVED: To provide an RDS data demodulator capable of highly accurately attenuating ARI signals without increasing a circuit scale and obtaining RDS data stably at all time regardlessly of the presence/absence of ARI modulation signals without causing any difference of the obtaining time of the RDS data. ;SOLUTION: This RDS date demodulator is provided with an analog/digital conversion means 18 for inputting analog FM demodulation signals and converting the analog FM demodulation signals to digital FM modulation signals, a first infinite impulse response type filter 20 for inputting the digital FM modulation signals and attenuating the ARM modulation signals provided with a transmission zero point at 57 kHz, a second infinite impulse response type filter 22 for inputting the output of the infinite impulse response type filter 20 and extracting RDS modulation signals provided with passing characteristics 57 kHz and an RDS demodulation means 24 for inputting the output of the second infinite impulse response type filter 22 and outputting RDS data signals and reproducing clock signals for RDS data demodulation from the input signals.;COPYRIGHT: (C)1999,JPO