Abstract: In the present technique of duplex local oscillator technique provided, a radio frequency local oscillator frequency and a duplex local oscillator frequency at a selected timeslot are assessed (516, 520) to provide a radio frequency local oscillator signal (518) and a duplex local oscillator signal (522), respectively. The duplex local oscillator signal and the radio frequency local oscillator signal are mixed (524) to provide a converted radio frequency local oscillator signal, which is then provided (526) for output.

Abstract: A block edge detector (310) determines (510) whether a wireless communication transmission with a first modulation having excess spectral emissions will be transmitted at a frequency on a block edge (120). In response, a modulator selector (320) changes (530) the wireless communication transmission to a second modulation with lessened spectral emissions. Preferably, the second modulator (340) is operably coupled to an alternative lookup table (360) wherein phase trajectory entries likely to cause excess spectral emissions such as spurious emissions are smoothed. The entries may be smoothed by filtering, non-linear extrapolation, and/or linear extrapolation. Alternatively, the second modulator (340) uses an alternative lookup table (360) that is a GMSK modulator with BT less than 0.3.

Abstract: A battery and component monitoring and notification device for a garage door operator is shown that provides telephone or internet notification when back-up batteries or other components require replacement. The device uses a programmable information processor to monitor the condition of back-up batteries or other components, actuates a telephone line interface to dial out a stored telephone number, and then actuates a voice control chip to play a stored telephone message. The telephone number and message are inputted by the user. The device may also provide notification over the internet by telephone line or other internet connection system. In addition, the device uses one or more battery chargers that each operate in one of two charging modes depending on the level of charging current to each battery.

Abstract: A receiver (10) corrects for dynamic DC offsets by utilizing an open loop predictive DC offset correction stage (18) to respond instantly to changes in AGC settings on a timeslot by timeslot basis. The receiver has an AC coupled baseband receiver and has memory (22) for storing calibration offset data (24 and 26) representing a calibration offset voltage value for each automatic gain control (AGC) state determined relative to a known reference value. The predictive DC offset stage (18) predicts a predictive DC offset correction value (74 and 76) for a selected timeslot using stored calibration offset data (24 and 26) and an average of stored calibration offset data corresponding to AGC states for all timeslots in a given frame.