Novatel Inc.

Wi-lan Inc.

James L Petersen

A carrier phase correction sub-system for use with a GNSS receiver that utilizes an active null and beam steering controlled radiation pattern antenna (CRPA) determines carrier phase corrections that compensate for antenna phase center movements in the carrier phase measurements taken from the CRPA filtered signal. The carrier phase sub-system utilizes measured radiation patterns, angles of incidence of the satellite signals at the CRPA, and the applied weights to determine carrier phase corrections to be applied to the CRPA filtered signals from which the carrier phase measurements are later taken or to the carrier phase measurements depending on the dynamics of the jamming signal. With the carrier phase corrected, the GNSS receiver may utilize known RTK techniques to resolve carrier cycle ambiguities.

GNSS positioning system including an anti-jamming antenna and utilizing phase center corrected carrier

A system for determining precise position includes a chirp receiver that processes broadcast chirp signals in the frequency domain to distinguish direct path signals from multipath signals. The chirp receiver processes the received chirp signals, which consist of respective pulsed frequency sweeps, by combining a received chirp signal with a synchronized locally generated chirp signal and phase adjusting and concatenating the results over multiple sweeps, based on estimated clock phase errors and expected phase rotations of the direct path signals, to produce a sine wave. The phase adjustment and concatenation allows the use of longer Fast Fourier Transforms (FFTs) that, in turn, provide increased accuracy of frequency estimation and separate component signals that are very close in frequency. The phase adjustment and concatenated signals are processed in the frequency domain using an FFT and a frequency corresponding to the direct path signal is identified by the lowest frequency bin in which power is above a predetermined noise threshold. The receiver then determines a time delay based on the identified frequency and uses the time delay to calculate accurate clock phase error. The system may then determine position based on associated pseudorange measurements.

System for determining precise position including a chirp receiver utilizing phase precessed chirp signals

A chirp receiver processes broadcast chirp signals in the frequency domain to distinguish direct path signals from multipath signals. The receiver processes received chirp signals consisting of respective pulsed frequency sweeps by combining the signals with a synchronized local chirp signal and phase adjusting and concatenating the results over multiple sweeps based on estimated clock phase errors and expected phase rotations of the direct path signals, and produces a sine wave. The phase adjustment and concatenation allows the use of longer Fast Fourier Transforms, which provide increased accuracy of frequency estimation and separate component signals that are very close in frequency. The frequency corresponding to the direct path signal is identified by the lowest frequency bin in which power is above a predetermined noise threshold. The receiver then determines a time delay based on the identified frequency and uses the time delay to calculate accurate clock phase error and position.

Chirp receiver utilizing phase processed chirp signals

In a wireless communication system, information is exchanged between a base station and a client station. The base station grants at least one allocation unit to a client station. The base station receives data from the client station using the allocation unit over the wireless link. The allocation unit substantially comprises mirror image pairs of subcarriers. Each mirror image pair of subcarriers includes a first subcarrier and a second subcarrier which are respectively disposed on opposite sides of a DC subcarrier by an equal frequency amount.

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Calgary, Canada

James L Petersen