Abstract: Methods and systems for determining the location of a Bluetooth device using a standard broadcast packet containing known data. Multiple antennas are used to take measurements of the packet are converted into in-phase and quadrature components, then a low-pass filter is applied. The known data presents an in-phase and quadrature spectrum that is a continuous wave-tone representation of the packet signal in the passband of the low-pass filter. Multiple measurements are used to determine the phase difference of the filtered measurements at the different antenna locations. Phase difference is used to determine the location of the device.

Abstract: Systems and methods for providing personal radar, object presence detection, and object localization are provided. Multiple devices that perform high-resolution ranging can be operated to perform radar in an area, detect objects and motion of objects in the area, and generate a virtual steerable antenna.

Abstract: Systems and methods for high-clock synchronization and stability are disclosed.

Abstract: Systems and methods for providing personal radar, object presence detection, and object localization are provided. Multiple devices that perform high-resolution ranging can be operated to perform radar in an area, detect objects and motion of objects in the area, and generate a virtual steerable antenna.

Abstract: A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator.

Abstract: A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator.

Abstract: A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator.