| 摘要 |
<p>The number of multiplies per second required in a digital FSK modem receiver using a tracking phase lock loop demodulator (20) is greatly reduced by using an 800 Hz sampling rate band pass filter (16) to isolate the carrier and its sidebands, operating the phase lock loop demodulator (20) at the 800 Hz sample rate which is just sufficient to satisfy Nyquist's theory for the frequency band passed by the filter, and interpolating the detected data samples by using 7200 Hz sampling low pass filter (36) in the output.</p> |
