Motorola Corporation

Iposi, Inc.

Motorola Mobility LLC

Christopher N Kurby

Eric Derbez

Keith Andrew Olds

Richard M Lee

Gregory B Vatt

Kevin M Thill

Michael W Frenzer

Derek Glass

Armin Werner Klomsdorf

David G Wiatrowski

Louis Jay Vannatta

Matthew Richard Miller

David Ryan Haub

Brian David Storm

Gregory W Chance

Richard E Mach

John William Arens

Robert J Locascio

Joan E Zocher

William Paul Alberth, Jr

Michael D Kotzin

Kenneth Anderson Stewart

Dale Gerard Schwent

Thomas Michael King

James P Phillips

Peter Nanni

Charles Philipp Binzel

Greg R Black

Arthur Christopher Leyh

James P Redden

Terry K Mansfield

Raul Olivera

Ronald F Buskey

Gary R Reynolds

Bradley B Bakke

Michael J Andresen

Krsman Martinovich

Ross E Ruthenberg

Donald R Beyer

Dwight D Walthers

Martin V Seitz

Percy P Batlivala

John P Monson

Kevin L Fluharty

Michael P Gaynor

Joe Martin Smith

Gary Parker English

Stephane Laurent Baills

Daniel T Buhmann

William Herbert Darden, Iv

William P Alberth

Joseph Cramer, Iii

Anne P Davies-Walsh

Kathleen Helen Ryan

Thomas R Gaynor

Jay G Smith

Stephane L Baills

Approaches for detecting and/or rejecting fraudulent positioning system signals at one or more positioning system receivers. The receivers may establish a time search window that may be maintained beyond a time in which a fraudulent signal is expected to move away from an authentic signal a sufficient amount so as to fall outside the time search window. Various approaches are described for updating the time signal at the receiver to maintain accuracy without acquiescing to the introduced bias of a fraudulent signal. Also, an approach for evaluation of candidate signals for consistency at one or more stationary receivers is described. Also, approaches for collective evaluation of signals provided from networked receivers are described to provide sentry receivers operative to detect and alert the presence of a fraudulent signal.

Trusted signal acquisition in positioning system receivers

Determination of one or more timing (phase) and/or frequency corrections to be made to a local time base of a receiver device to synchronize the local time base with the time of GPS or other highly accurate time base. Timing packets from one or more grandmaster devices whose time bases are substantially the same as that of GPS or the like and/or positioning system signals (e.g., GPS signals) directly from a positioning system are received and manipulated to determine the timing and/or frequency corrections. The corrected time base may be used to assist in acquiring such positioning signals to allow for higher accuracy correction and/or for downstream communication operation. The present utilities are advantageous such as when a sufficient number of channels (e.g., four) from the receiver device to positioning system satellites are unavailable to synchronize the local time base to the GPS or other accurate time base.

Internet-based time and frequency recovery for position fixing of GNSS receiver

Wave based signals such as radio transmissions are susceptible to frequency alterations caused by the relative movement between a transmitter and a receiver. In a satellite context, the radio signals emitted by a satellite based transmitter may take on a frequency higher or lower than the actual frequency at which they are generated depending on whether the satellite is moving toward or away from the receiver, respectively. By calculating the theoretical frequency shift (Doppler shift) that should occur if a signal travels directly from a satellite to a receiver, the actual frequency of the signal as received can be used to determine if the signal's integrity is sufficient or if it has been compromised by some sort of interference or malfunction.

Receiver integrity monitoring using doppler analysis

Location of a device within a monitored environment with compromised communication with ranging communication nodes. Specifically, an intermediate device previously located by communication with ranging communication nodes is provided to provide a ranging signal to a device to be located. The device to be located may in turn use a ranging signal received from communication with the previously located device and one or more ranging communication nodes to resolve a location.

Cooperative receiver system with mobile to mobile assistance

Positioning, navigation, and timing ('PNT') signals, such as those used in GNSS or LORAN systems, may be vulnerable to spoofing attacks. To generate trustworthy time and location data at a receiver, one must at least reduce the likelihood of or be capable of detecting spoofing attacks. Embodiments of the present invention, as presented herein, provide solutions for detecting spoofing of PNT signals. Various aspects incorporated into the described embodiments which assist in detecting spoofing attacks may include but are not limited to: monitoring the SNR of received PNT signals of a first modality and switching over to an alternate PNT modality when an anomaly is detected, comparing data associated with signals of multiple PNT modalities to identify a discrepancy indicative of spoofing on one of the multiple PNT modalities, and implementing a security regime to prevent spoofers from being able to produce perceivably authentic, but corrupt, replica signals of a PNT modality.

Protected positioning, navigation, or timing signals resistant to spoofing

The present disclosure is directed to utilities (methods, systems, apparatuses) associated with improving the signal-to-noise ratio of a wireless signal at a receiver. It is known in the art to correlate a received signal with a replica signal generated at the receiver to improve reception. However, the inventors have determined that correlation using a replica signal which is not completely accurate may be detrimental. An improved method of correlation disclosed herein includes identifying data bits which are predictable and performing correlation with respect to those data bits while ignoring data bits which are identified as unpredictable. This method may have particular advantages in the case of receivers having attenuated reception (e.g., indoors) after losing a data connection used for receipt of assistance data.

GPS holdover with selected bit prediction or omission

Determination of a signal loss profile relative to a receiver based on measured signal power of a sounding signal from a sounding transmitter having a known signal power in free space relative to the receiver. The signal loss profile may include a plurality of signal loss values corresponding to a plurality of received sounding signals at the receiver. In an embodiment, the sounding signal may comprise a GNSS navigational signal (e.g., a GPS signal). The signal loss profile may be used to extrapolate signal loss for a transmitter collocated with the receiver. In turn, the signal loss profile may be used in conjunction with a shared spectrum system to model a signal propagation from the collocated transmitter when determining allocation of a shared spectrum resource of the shared spectrum system.

Tomographic loss factor estimation

Data bandwidth reduction in positioning system signals. Specifically, a first, relatively easily acquired signal may be analyzed to determine if and/or to what extent to decimate a second signal. The second signal may comprise a higher encoded data rate (e.g., a chip rate). In turn, decimation of the second signal based on characteristics of the first signal may allow for more efficient processing of the second signal.

Receiver performance using GNSS signals having different frequencies

A GNSS cooperative receiver system that can be utilized when one or more GNSS receivers is in a compromised position where it cannot receive direct signals from a sufficient number of GNSS satellites. This may in the interior of an office building or multi-dwelling unit, which may be in the vicinity of other tall buildings. The receivers determine their relative positions from one of various ranging techniques, and then with this relative position information, pseudoranges, and correlation values from the various GNSS receivers, the best GNSS solution can be determined for the group of cooperative receivers. This could include two or more receivers in a group. There also related techniques for one receiver to be a designated, remote anchor for other GNSS receivers that need such assistance.

GNSS cooperative receiver system

Synchronization of a time base at a local clock to a reference time. Initially, correction data (e.g., synchronization data) may be derived from packet data received over an asynchronous packet-switched network (e.g., the internet). Correction data derived from the packet data may be used to correct at least a portion of the time base (e.g., a frequency component). In turn, once the time base is corrected (e.g., to better than a predetermined quality threshold), the source of synchronization data may change to an alternate (e.g., more accurate source) such as positioning signals from a positioning system. In this regard, the corrected time base may be used to assist in acquiring such positioning signals to allow for higher accuracy correction. Furthermore, use of the positioning system may allow for correction of a phase of the time base (e.g., to align the phase to the positioning system. In turn, an accurate time base may be utilized (e.g., for location determination using the positioning system) and/or other contexts such as a downstream communication operation. For instance, a device employing the synchronization techniques described herein may be an LTE base station used to facilitate downstream communication with another device by use of the synchronized time base.

Hybrid timing for a GNSS receiver

Approaches to signal processing using tapered coherent integration time period durations. In this regard, signal processing of received signals (e.g., received satellite navigation signals) may be received at a receiver. The received signals may be processed in a coherent integration process whereby the duration of subsequent coherent integration time periods are reduced in response to errors resulting from frequency instability that grows in time. As such, relatively long durations for coherent integration times may result in improved signal to noise ratios (SNRs) for integrated signals in initial coherent integration time periods. However, as errors that are introduced into the signal processing due grow over time, the durations of subsequent coherent integration time periods may be reduced, thus reducing the effect of the error in a SNR of resulting integrated signals. In turn, receiver sensitivity may be improved.

Tapered coherent integration time for a receiver of a positioning system

A method and apparatus for synchronizing a system clock with a serving cell () associated with a first radio access technology and monitoring an adjacent cell () associated with a second radio access technology is provided. A communication device () includes a first synchronization device () capable of synchronization with the serving cell () and a second synchronization device () capable of independently synchronizing with the adjacent cell (). The first synchronization device () and second synchronization device () include independent frequency correction modules (). Thus, the second frequency synchronization device () may be corrected per the adjacent cell () while the first synchronization device () remains synchronized with the serving cell (). Thus, the same corrected system clock may be used between two radio access technologies.

Method and apparatus for automatic frequency correction in a multimode device

A multimode wireless communication device capable of communicating pursuant to first and second communication protocols, including a method wherein a determination is made () as to whether a harmonic generated during transmission in one protocol interferes with reception in another protocol, and wherein transmission is suspended while receiving only if a harmonic generated during transmission interferes with reception. In some embodiments, the transmitter is temporarily operated in compressed mode to enable the suspension.

Multi-mode wireless communication device and method

Growing community of inventors

Elmhurst, IL, United States of America

Christopher N Kurby