The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 25, 1992
Filed:
Mar. 21, 1991
Glyn Roberts, Calgary, CA;
Kiomars Anvari, Calgary, CA;
NovAtel Communications, Ltd., Calgary, CA;
Abstract
In a digital radio-telephone receiver, an open-loop arrangement for generating a received-signal-strength-indicating ('RSSI') value suitable for use in mobile assisted hand-off within a cellular telephone system. The receiver has an amplifier for amplifying a received signal with a gain controlled by a gain-control signal, and an automatic-gain-control circuit ('AGC') responsive to the amplitude of the amplifier output and coupled in a feedback-loop for applying an AGC signal to the amplifier as the gain-control signal. An RSSI value is generated by (i) opening the AGC feedback loop so that the AGC output signal is not applied to the amplifier, (ii) applying a ramp signal of increasing amplitude to the VGA while the AGC monitors the signal envelope, and (iii) when the signal envelope passes a pre-selected threshold, applying the then-occurring ramp-signal value to a calibrated look-up table to obtain the corresponding RSSI value stored therein. Preferably, the receiver also employs a digital multiplexer ('MUX'), which provides to the amplifier as the gain-control signal, in response to a select signal, the ramp signal during a first period of time, and the AGC signal during a second period of time.