| 摘要 |
A digital demodulator demodulates and separates the individual components of a digitized stereo multiplex signal which contains a narrowband information channel at three times the pilot signal frequency. Demodulation is accomplished by means of five digital demodulators to which respective carriers are applied from a carrier conditoning circuit. Each carrier has a frequency of the pilot signal frequency, twice the pilot signal frequency or three times the pilot signal frequency. The carriers are generated as data word sequences which contain only the values +1, -1 and 0. The sampling interval for the remaining carrier is 60 DEG , beginning from 0 DEG . The signal sampling frequencies are adapted to the different sampling frequencies of the carriers by means of decimation circuits. Each of the six components is freed from interfering adjacent signals by a low-pass filter.
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