Patent
1978-07-21
1979-09-04
Olms, Douglas W.
325 52, H04M 704
Patent
active
041669274
ABSTRACT:
In a mobile radiotelephone system, N separate modulated carrier signals in N frequency channels are applied to a demodulating radio receiver which provides a succession of N different output signals each having idle and busy states. An idle and signal-to-noise detector monitors each of the output signals of the radio receiver. The detector provides a first logic signal when one of the output signals concurrently exhibits an idle state and has at least a predetermined minimum signal-to-noise level, and provides a second logic signal at all other times. A receiver switching circuit, in response to the second logic signal, causes the receiver to cyclically switch to each of the N frequency channels. When the receiver switches to a carrier signal which causes the detector to produce a first logic signal, the switching circuit causes the receiver to lock onto that particular carrier signal. Improved operation results from a gain control circuit which reduces the gain sensitivity of the receiver upon a change in state of the detector output signal from a first logic signal to a second logic signal. The gain sensitivity is then slowly increased as the receiver cyclically switches to each of the N frequency channels. When an idle receiver output signal is detected having at least the minimum level of signal-to-noise, the receiver switching circuit locks the receiver onto the particular carrier signal. This technique assures that the first such detected signal will provide the best frequency channel for the demodulating radio receiver.
REFERENCES:
patent: 3555424 (1971-01-01), Malm
patent: 3913017 (1975-10-01), Imaseki
patent: 4112257 (1978-09-01), Frost
British Columbia Telephone Company
Gilbert Douglas M.
Olms Douglas W.
LandOfFree
Apparatus and method for frequency channel selection in a radiot does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for frequency channel selection in a radiot, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for frequency channel selection in a radiot will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2129148