Lojack Corporation

Lucent Technologies Inc.

Michael W Goodwin

James A Justice

Jesse L Rhodes

Fabio Meacci

James Russell Blodgett

Robert B Ward

Harold Allan Simpson

Stuart Warmink

James P Moffatt

Gerald L Frazer

Kyoo J Lee

David L Sprague

Karen E Leonard

Alexis M Butrym

Fan Zhang

Bruce R Bouchard

Systems and methods for power management systems are disclosed. One embodiment of the invention includes a power management system for a vehicle locating unit, the vehicle locating unit having a receiver for receiving at an assigned message frame an intermittent transmission from a communications source, wherein each intermittent transmission includes at least one assignable message frame, the power management system including a processing device for controlling wake and sleep modes of the receiver and a memory for storing a plurality of memory bit patterns for comparison with a pattern of bits contained in some portion of an assigned message frame, wherein the processing device is configured to perform the following steps: index to the receiver's assigned message frame in the intermittent transmission, re-enter wake mode after indexing, and subject the receiver to a constant average current draw.

Power management system and method for vehicle locating unit

Improved power management for a vehicle locating unit is achieved by receiving a transmission from a communication source, each transmission including at least one message frame having a data field and at least one auxiliary field; entering a wake mode upon indexing the assigned message frame of the receiver in the transmission; matching the pattern of bits of at least one auxiliary field of the indexed frame with one or more stored patterns of bits expected for that auxiliary field; and returning to the sleep mode as soon as a mismatch is determined or processing the message if no mismatch occurs.

Synchronization for achieving low power battery operation of a vehicle locating unit in a stolen vehicle recovery system whose radio receiver receives periodic transmissions, includes receiving periodic transmissions; turning on a radio receiver for a limited time to detect an expected message; if an expected message is not found, turning off the receiver and turning it on again after a time asynchronous with the transmission period; and after finding an expected message, waiting for the period of the transmissions less the length of an expected message and then looking for a synchronization symbol in the expected message and synchronizing subsequent actuation of the receiver using that synchronization symbol.

Synchronization system and method for achieving low power battery operation of a vehicle locating unit in a stolen vehicle recovery system which receives periodic transmissions

An adaptive controller generates a sequence of dither signals for each of a plurality of control parameters. Each dither signal sequence is uncorrelated with every other dither signal sequence. Each nominal control signal has the first of its respective dither signal values simultaneously summed with it to form the control parameter values used by the controller. Updated control signals are applied in parallel to the controller outputs and a performance measure is taken and stored. The second signals in the dither control sequences are then summed with their respective nominal controls and applied in parallel to the controller and a second performance measure is taken and stored. This process is repeated for the length of the dither control signal sequence to yield a sequence of performance measurements. The sequence of performance measurements is correlated with each of the dither sequences, forming sequences of correlator outputs, one for each control signal. Each correlator output sequence is integrated and, depending upon the value of a correlator's integration output, the corresponding nominal signal has it's dither value added to or subtracted from it to form the respective, updated control values.

Apparatus and method for adaptive control

A central controller, such as an RF distribution shelf (RFDS) of a hybrid fiber/coax (HFC) access system, keeps track of the different channels assigned to different remote units, such as the network interface units (NIUs) of the HFC system. Information about the different channel assignments (e.g., for upstream channels) is broadcast to the remote units as part of the overhead bits in each of the downstream channels. Each remote unit monitors the broadcast messages and, over time, updates its own version of the data structure containing the channel assignments, as appropriate. In one embodiment, the central controller also transmits a second type of broadcast message indicating when changes in the channel assignments occur. In this embodiment, the second type of broadcast message is transmitted more frequently than the entire data structure containing the channel assignments, and the remote units only update their copies of the data structure when the second type of broadcast message indicates a change in the data structure.

Channel switching control for a communication system

A method for linearizing amplifiers by measuring the intermodulation products at the output of the linearized amplifier using minimum additional hardware without the performance problems associated with pilot tones. In one embodiment, the amplifiers are adaptively linearized using performance monitoring radios. Specifically, the performance monitoring radios are used to measure the signal levels of the intermodulation products in unused communication channels. Such measurements are then used to adaptively linearize the amplifiers and reduce the levels of intermodulation products.

Method for adaptively controlling amplifier linearization devices

A method for improving the linearity of a signal coupling device having a ferrite core transformer comprises the step of demagnetizing the ferrite core. The resulting signal coupler has substantially zero remanent magnetism.

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North Andover, MA, United States of America

Michael W Goodwin