Vehicle locating unit with improved power management method
View Patent ↗A vehicle locating unit with improved power management. A receiver receives a signal from a network of communication sources. A signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. A power management subsystem is responsive to the signal strength monitoring subsystem and is configured to alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source according to a predefined sequence.
1. A vehicle locating unit with improved power management, the vehicle locating unit comprising:
a receiver which receives a signal from a network of communication sources;
a signal strength monitoring subsystem for determining which of the communication sources are transmitting the strongest signals; and
a power management subsystem responsive to the signal strength monitoring subsystem and configured to:
alternatively enter sleep and wake-up modes,
synchronize the wake-up mode to the communication source transmitting the strongest signal, and
test the signal strength of at least one additional communication source according to a predefined sequence.
2. The vehicle locating unit of claim 1 in which the power management subsystem is configured to:
test and store the identity of two communication sources with the two strongest signals,
switch to synchronization with any communication source having a signal stronger than the strongest signal of the two stored communication sources, and
store the identity of any communication source with a signal stronger than the signal of any previously stored communication source.
3. The vehicle locating unit of claim 1 in which there are n communication sources each transmitting a signal at a different time every n seconds.
4. The vehicle locating unit of claim 3 in which n is 8.
5. The vehicle locating unit of claim 1 in which the power management system is configured to include a start-up mode wherein all communication sources are tested.
6. The vehicle locating unit of claim 1 in which the power management subsystem is implemented in a microcontroller.
7. The vehicle locating unit of claim 1 in which the power management subsystem is configured to power down the receiver during the sleep mode and to power up the receiver during the wake-up mode.
8. The vehicle locating unit of claim 1 in which the signal strength monitoring subsystem includes a demodulation circuit.
9. The vehicle locating unit of claim 8 in which the demodulation circuit is a component of the receiver.
10. A system comprising:
a receiver which receives a signal from a network of communication sources;
a signal strength monitoring subsystem for determining which of the communication sources are transmitting the strongest signals; and
a power management subsystem responsive to the signal strength monitoring subsystem and configured to:
alternatively enter sleep and wake-up modes,
synchronize the wake-up mode to the communication source transmitting the strongest signal, and
test the signal strength of at least one additional communication source to ensure the wake-up mode is synchronized to the communication source transmitting the strongest signal.
11. A vehicle locating unit with improved power management, the vehicle locating unit comprising:
a receiver which receives a signal from a network of communication sources;
a signal strength monitoring subsystem for determining which of the communication sources are transmitting the strongest signals; and
a power management subsystem responsive to the signal strength monitoring subsystem and configured to:
test and store the identity of two communication sources with the two strongest signals,
alternatively enter sleep and wake-up modes, the wake-up mode synchronized with the communication source transmitting the strongest signal,
test the signal strength of at least one additional communication source according to a predefined sequence,
switch to synchronization with any communication source having a signal stronger than the strongest signal of the two stored communication sources, and
store the identity of any communication source with a signal stronger than the signal of any previously stored communication source.
12. A vehicle locating unit power management system comprising:
a memory; and
a controller configured to:
alternatively output sleep and wake-up mode signals,
store in said memory the identity of at least a first communication source presenting the strongest signal,
test the signal strength of at least one different communication source during the wake-up mode,
synchronize the wake-up mode to the communication source identified in said memory, and
update the memory to store the identity of a different communication source presenting a signal stronger than the first communication source.
13. A vehicle locating unit with improved power management, the vehicle locating unit comprising:
a receiver which receives a signal from a network of communication sources;
a signal strength monitoring subsystem for determining which of the communication sources are transmitting the strongest signals; and
a power management subsystem responsive to the signal strength monitoring subsystem and configured to:
test and store the identity of two communication sources with the two strongest signals,
switch to synchronization with any communication source having a signal stronger than the strongest signal of the two stored communication sources, and
store the identity of any communication source with a signal stronger than the signal of any previously stored communication source.