| 摘要 |
A radio receiver discriminates between narrowband and wideband radio frequency (RF) signals on the basis of the rate of increase of the integrated energy level of the received signal. The receiver comprises a receive section adapted to receive and downconvert RF input signals to intermediate frequency (IF) signals, and a received signal strength indicator coupled to the receive section and providing a receiver energy signal corresponding to the energy of the IF signals. A discrimination section receives the energy signal, and determines whether the RF input signals are narrowband or wideband by detecting the rate of increase of the integrated level of the receiver energy signal. The discrimination section further comprises a first threshold detector providing a first triggering signal upon the integrated level of the receiver energy signal reaching a first level, a second threshold detector providing a second triggering signal upon the integrated level of the receiver energy signal reaching a second level, and a timer providing a timing signal corresponding to elapsed time between the first and second triggering signal. The RF input signals comprise wideband signals when the timing signal is less than a predetermined value, and narrowband signals when the timing signal is at least equal to the predetermined value.
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