摘要 |
<p>A receiver front end ( 302 ) receives a known Stop Waveform ( 114 ) comprising a predetermined symbol pattern on a voice channel, the Stop Waveform sent at the end of a transmission. A processor ( 304 ) coupled to the receiver front end terminates ( 512 ) the reception of the voice channel in response to detecting the Stop Waveform. The processor computes ( 504 ) a plurality of characteristics derived from the received signal, including a carrier-to-noise ratio, a maximum normalized symbol correlation energy over all symbols of the Stop Waveform, and a number of small and a number of large normalized symbol energy values. The processor detects ( 506 ) the Stop Waveform by comparing the plurality of characteristics with a corresponding plurality of predetermined thresholds.</p> |