| 摘要 |
<p>A noise detector (56, 56'), suitable for use in a radio frequency (RF) communications device, such as a CT-2 base station (12) or handset (20), detects a broken RF link by sampling the energy level of a signal for a short period of time. Thus, the audio signal output to a telco interface (40) of the base station (12) or the speaker (60) of the handset (20) can be muted by a signal from the controller (48, 48') in response to broken link detect by the noise detector (56, 56'). The radio communications device (12, 20) receives an RF signal via receiver circuitry (50, 50b), samples (106, 114, 116) the received signal over a predetermined time period (N) to measure a plurality of signal energy levels (112), and determines whether the RF link is broken or not in response to an average of the plurality of signal energy levels exceeding or not exceeding a predetermined threshold (118).</p> |
