Abstract: A system for estimating parameters of an incoming signal is provided. At least one antenna is coupled to at least one suitable receiver. The antenna(s) are spatially translated in an arbitrary trajectory. As the antenna(s) is being spatially translated, a data processing means samples the incoming signal at set intervals based on a clock signal provided by a system clock. By sampling the incoming signal at different times at different spatial locations on the arbitrary trajectory, the system acts as a synthetic antenna array. The different samplings of the incoming signal at different times and positions provide signal diversity gain as well as different readings which can be used to estimate and/or calculate various parameters of the incoming signal. The different samplings can be used to detect the incoming signal, estimate its angle of arrival, estimate its time of arrival, as well as other parameters.
Type:
Grant
Filed:
September 18, 2009
Date of Patent:
December 25, 2012
Assignee:
Her Majesty the Queen in right of Canada as Represented by the Minister of National Defence
Inventors:
John Nielsen, Gerard Lachapelle, Ali Broumandan
Abstract: There is provided a wireless communication device includes a transmitter configured to transmit a known signal in each of a plurality of first directions different from each other, a receiver configured to receive a plurality of first reflected waves, each of the plurality of first reflected waves being generated by the known signal transmitted in each of the plurality of first directions and to detect each of a plurality of first reception intensities, each of the plurality of first reception intensities being associated with each of the plurality of first reflected waves; and a controller configured to determine a transmission direction of a radio signal addressed to a first wireless terminal, based on the plurality of first reception intensities and to control the transmitter to transmit the radio signal in the transmission direction.
Abstract: An exemplary radio-based navigation system uses a small multimode direction-finding antenna and a direction-finding receiver capable of determining platform position, velocity, attitude, and time while simultaneously providing protection against narrowband and broadband sources of interference. Global Navigation Satellite System (GNSS) signals such as those from the Global Positioning System (GPS) provide attitude measurements with a compact multimode direction-finding antenna (e.g., a small two-arm spiral with improved angle-of-arrival performance over the entire hemisphere enhanced through the use of a conductive vertical extension of the antenna ground plane about the antenna perimeter and/or conductive posts placed evenly around the antenna perimeter) which provides simultaneous protection against jammers. The multimode spiral may be treated as an array of rotationally-symmetric antenna elements.
Abstract: A system for localizing an autonomous vehicle to a target area can include a position indicator adapted for association with the vehicle in a three dimensional configuration, a detection device configured to detect the position indicator, a computation device configured to compute a position of the vehicle based on the detected position indicator and the relationship of the configuration to the vehicle orientation, a transmitter configured to receive information from the computation device and produce a signal carrying the information, a receiver configured to receive the signal from the transmitter and filter the information therefrom, and a control system configured for association with and control of one or more directional control components of the vehicle, the control being based on the information received from the receiver relating to localizing the vehicle to the target area. A method of for localizing a vehicle to a target area is also disclosed.
Type:
Grant
Filed:
December 18, 2009
Date of Patent:
October 30, 2012
Assignee:
ReconRobotics, Inc.
Inventors:
Robert S. Malecki, Lue Her, Ryan J. Thompson, Anthony H. Giang
Abstract: A reception system including a receiver coupled to a processing means, the receiver comprising a number N of antennas, each being able to pick up signals representative of incident waves and to deliver a pulse dependent on said signal, N being an integer. Said receiver includes: N delay lines respectively coupled to each of said N antennas, each delay line being able to delay the signal delivered by the antenna with which it is associated by its own time delay, a coupling means able to sum the N signals delivered by the N delay lines, so as to deliver an output signal comprising a series of N time-shifted pulses. The processing means includes a measurement means able to measure the signal delivered by the coupling means and to deliver as output a signal formed by measurement samples, representative of the N pulses delivered by the N antennas.
Abstract: Method embodiments are disclosed to determine arrival directions of electromagnetic signals that have a known signal frequency and a known guided signal wavelength. These methods are realized with an antenna configured to define, at the signal frequency, at least one metamaterial cell between first and second signal ports. They then include the step of rotating the antenna until the differential power from the first and second signal ports is substantially zero and then determining the arrival direction as a normal to the metamaterial cell. In other method embodiments, the antenna is stationary and a differential power is determined wherein the differential power is defined as the difference between received powers from the first and second ports. The arrival direction of electromagnetic signals are then determined from the differential power.
Abstract: A system used for calibrating a direction-finding system. A device may include a signal receiver array. The signal receiver array may be utilized to determine the direction of arrival for signals emitted by other devices, and therefore, may be used to resolve the direction towards another device using the received signal. For example, an external tag may be utilized to emit a wireless signal usable inducing a response in each signal receiver of the signal receiver array. The device may also include one or more sensors usable in determining device orientation and/or a change in device orientation. The combined signal receiver response information and orientation information may be recorded at various instants as the device is moved for use in calibrating the antenna array.
Type:
Grant
Filed:
November 20, 2007
Date of Patent:
September 11, 2012
Assignee:
Nokia Corporation
Inventors:
Antti Paavo Tapani Kainulainen, Andreas Richter, Fabio Belloni
Abstract: A method and apparatus for determining stream weights is provided herein. During operation, an uplink direction of arrival (DOA) and a downlink direction of departure (DOD) calibration procedure is implemented using uplink signals and GPS information from a subset of mobiles without the need of calibration circuitry at the base. Because the presented calibration procedure needs no new hardware it can be deployed in existing deployments with only a soft-ware upgrade.
Abstract: A system for establishing a wireless link from a wireless communication device (WCD) to at least one target device. The process of both identifying the target device and establishing a link to this device may incorporate the orientation and/or movement of the WCD into the procedure in lieu of the extensive use of traditional menu interfaces. A WCD may interpret a combination of orientation and/or movement as an approximate target device location that may be utilized to narrow the total population of all located devices into a subset containing those devices located within of near the approximate target device location. The subset of devices may be formulated and displayed as potential target devices for selection by a user. If any of the potential target devices are known by the WCD, a link may be established automatically.
Type:
Grant
Filed:
June 12, 2007
Date of Patent:
September 4, 2012
Assignee:
Nokia Corporation
Inventors:
Joni Jorma Marius Jantunen, Kimmo Heikki Juhana Kalliola, Antti Paavo Tapani Kainulainen
Abstract: A method for interpolating steering vectors a(?) of a sensor network, the sensor network receiving signals transmitted by a source, characterized in that, for the interpolation of the steering vectors a(?), use is made of one or more omnidirectional modal functions z(?)k where z(?)=exp(j?) where ? corresponds to an angle sector on which the interpolation of the steering vectors is carried out.
Type:
Grant
Filed:
June 9, 2008
Date of Patent:
August 21, 2012
Assignee:
Thales
Inventors:
Anne Ferreol, Jeremy Brugier, Philippe Morgand
Abstract: A navigation system/solution, suitable for use in a GPS-denied environment, may be implemented via a node, the node being mounted on-board a vehicle, such as a tactical aircraft. The system/solution allows for a single component of the node to obtain/determine a bearing measurement (via an orientation transfer scheme) and a range measurement (via a round trip timing scheme) based upon signals transmitted between the node and a second node, and further allows for the bearing and range measurements to be received and processed by a navigation processor of the node for determining a location of the node.
Type:
Grant
Filed:
February 26, 2010
Date of Patent:
July 10, 2012
Assignee:
Rockwell Collins, Inc.
Inventors:
David A. Anderson, Patrick Y. Hwang, Joseph M. Kelly
Abstract: Terrestrial-based positioning beacon networks may include first and second terrestrial-based positioning beacons that are configured to simultaneously transmit signals to a terrestrial receiver. The first terrestrial-based positioning beacon may be configured to modify its transmissions to the terrestrial receiver in response to an identification of potential interference with the transmissions from the first terrestrial-based positioning beacon or the second terrestrial-based positioning beacon to the terrestrial receiver. Related methods, beacons, and receivers are also described.
Abstract: A method includes generating a correlation vector of baseband-signal vectors based upon signals received from a plurality of sensor devices, generating a generalized Hankel matrix R representing a covariance matrix to which a spatial averaging is applied based upon the correlation vector, generating a kernel matrix ?1, which is a projection matrix onto noise subspace, by performing linear operation using submatrices R1 and R2 of the generalized Hankel matrix R, generating a kernel matrix ?2, which is orthogonal with the kernel matrix ?1, and estimating a direction of arrival of a signal based upon the kernel matrices ?1 and ?2.
Abstract: An RF signal detection process by incorporating direction detection of the RF signal along with energy detection to arrive at a signal of interest (SOI). The SOI is identified by matching direction detections and energy detections. Low-level and noise-like signals can be reevaluated for unresolved direction detections or energy detections. The RF signal detections can be filtered based on valid direction detections very early on in the processing chain to reduce the amount down-stream processing required.
Abstract: A parameter of interest of a signal, such as the angle of arrival of a target signal received by an antenna system having an array of antenna elements, is estimated by (a) obtaining disparate observations of the target signal received by the antenna system; (b) with a computer, processing the disparate observations of the target signal to determine a subset of a set of possible further obtained disparate observations of the target signal for processing to enable an optimal estimation of the angle of arrival of the target signal; (c) obtaining the subset of further disparate observations of the signal; and (d) processing the obtained subset of further obtained disparate observations to obtain the optimal estimate of the parameter of interest.
Abstract: An apparatus for estimating an angle of arrival includes: a plurality of direction synthesizing units shifting the phase of each of a plurality of signals received by an array antenna such that the angle of arrival of each of the received signals is changed by a predetermined change angle; and an estimation unit estimating the angle of arrival of the received signal by using radiation gains of two phase-shifted signals among the signals phase-shifted by the plurality of direction synthesizing units.
Type:
Application
Filed:
October 6, 2011
Publication date:
May 3, 2012
Applicant:
Electronics and Telecommunications Research Institute
Inventors:
Kyung Hwan Park, Sung Weon Kang, Seok Bong Hyun, Tae Young Kang, Byoung Gun Choi, Chang Hee Hyoung, Jung Hwan Hwang, Sung Eun Kim
Abstract: A technique for determining the angles of arrival of signals incident on an antenna array from directions within an angular region of interest involves supplying outputs of antenna elements of the antenna array to a number of different weight generators. Each of the weight generators produces a set of beam-forming weights that maximizes a signal-to-interference ratio of a locally generated signal corresponding to a look angle that is outside the region of interest, with signals at different look angles being supplied to the different weight generators. An annihilation operator is determined from the sets of beam-forming weights generated by the weight generators and from beam-forming vectors representing the look angles of the locally generated signals used in the weight generators. The annihilation operator is applied to a group of beam-forming vectors representing angles within the region of interest to determine angles of arrival of signals within the region of interest.
Abstract: A location estimation method using label propagation. The achieved location estimation method is robust to variations in radio signal strengths and is highly accurate by using the q-norm (0<q<1), especially, for calculating the similarities among radio signal strength vectors. The accuracy in location estimation is further improved by putting more importance on the time-series similarities. Specifically, the time-series similarity is calculated by using time-series values indicating the temporal order of radio signal strengths during the measurement. If the time-series similarity is larger than the similarity between the radio signal strength vectors, the time-series similarity is preferentially used. The exponential attenuation function can also be used for calculating the similarities, instead of the q norm (0<q<1).
Type:
Grant
Filed:
October 24, 2008
Date of Patent:
March 20, 2012
Assignee:
International Busines Machines Corporation
Abstract: A signal wave arrival angle measuring device includes: an observation data vector generation section generating an observation data vector necessary for an angle measurement of a signal wave from an electrical signal having been converted at a sensor group converting the signal wave of an observation target to the electrical signal; an ESPRIT angle measurement processing section calculating an arrival angle of the signal wave from the generated observation data vector; an arriving signal wave estimation section estimating information other than the arrival angle of the arriving signal wave from an angle measurement processing process data of the ESPRIT angle measurement processing at the ESPRIT angle measurement processing section; and a reliability determination section determining whether or not an angle measurement result of the calculated arrival angle is correct based on an estimation result of the arriving signal wave estimation section, and excluding an erroneous angle measurement result.
Abstract: A method for calibrating an antenna and signal processing system enabling angle of arrival (AOA) determination for a frequency hopping signal, in which a calibration coefficient is determined in response to one or more calibration signals injected into the system at one or more of the frequencies in the hopping sequence and proximate in time to reception of the communication signal. The calibration coefficients are reflective of a frequency and time dependent parameter of a path between the antenna and wireless location sensor. The AOA is determined as a function of the calibration coefficient and the radio frequency energy of the received communication signal. Several embodiments of the method are illustrated.
Type:
Grant
Filed:
January 11, 2008
Date of Patent:
February 28, 2012
Assignee:
Andrew, LLC
Inventors:
Joseph P. Kennedy, Jr., Thomas B. Gravely, John P. Carlson, Martin Alles, Doug Blackburn
Abstract: A method for locating a target wireless device is disclosed. At least one directional antenna is swept through a field of view at each of a plurality of sensing locations. A position is determined for each of the plurality of sensing locations. During the sweep at each of the plurality of sensing locations, a set of signal strength data for the target wireless device and a set of bearing information are collected. A plurality of lines of bearing are determined, one from each of the plurality of sensing locations to the target wireless device, based on the determined position, the collected set of signal strength data, and bearing information for each of the plurality of sensing locations. A target location of the target wireless device is determined based on an intersection of at least two lines of bearing from the plurality of lines of bearing.
Type:
Grant
Filed:
May 26, 2009
Date of Patent:
January 17, 2012
Assignee:
Assured Information Security, Inc.
Inventors:
Richard Michael Gloo, Jacob Michael Baker, Alexander James Williams, Jason S. Lashure, Robert James Durham, Nicholas Lawrence Owens
Abstract: A system for determining a propagation direction of a received electromagnetic wave includes a linear phased array of receiving antenna elements and a processing unit for processing signals received by the receiving antenna elements. The processor is arranged for generating, from the received signals, receiving data corresponding to a set of respective angular synthetic receiving aperture beams.
Type:
Application
Filed:
October 30, 2009
Publication date:
December 22, 2011
Applicant:
Nederlandse Organisatie voor toegepast- natuurwetenschappelijk onderzoek TNO
Abstract: In an embodiment, an apparatus includes a detector, direction finder, receiver, and range finder. The detector is operable to detect a target, and the direction finder is operable to determine a first direction to the target from the apparatus. The receiver is operable to receive a second direction to the target from a remote object, and the range finder is operable to determine from the first and second directions a range of the target from the apparatus. For example, the apparatus may be a first fighter jet, and the remote object may be a second fighter jet. By using directional information from both the first and second jets, a computer system onboard the first jet may compute a range to the target from the first jet more quickly and more accurately than by using directional information from only the first jet.
Type:
Grant
Filed:
February 2, 2009
Date of Patent:
December 20, 2011
Assignee:
BAE Systems Information and Electric Systems Integration Inc.
Abstract: A radio-based navigation system uses a small multi-mode direction-finding antenna and a direction-finding receiver to determine platform position, velocity, attitude and time while simultaneously providing protection against narrowband and broadband sources of interference. Global Navigation Satellite System (GNSS) signals such as those from a Global Positioning System (GPS) provide attitude measurements with a compact multi-mode direction-finding antenna (e.g., a small two-arm spiral with improved angle-of-arrival performance over the entire hemisphere enhanced through use of a conductive vertical extension of the antenna ground plane about the antenna perimeter and/or conductive posts placed evenly around the antenna perimeter) that provides protection against jammers. The multi-mode spiral may be treated as an array of rotationally-symmetric antenna elements.
Abstract: A method for determining a spatial orientation of a body, including receiving, by receiving equipment located with the body, at least three electromagnetic signal sets, each of the received signal sets having been transmitted by a different one of at least three separate transmitters at different locations, detecting, for each one of the received signal sets, information that partially defines a direction from the body to the transmitter from which the signal set was received, the detected information including one of two angles that fully define an arrival direction from which the body received the signal set in relation to a body frame, the detected information not including a second of the two angles, and determining the spatial orientation of the body, including yaw, pitch, and roll angles relative to a navigation frame, using the detected information for each one of the received signal sets.
Abstract: Marine personal locator system including personal transmitters activated by immersion and a receiver. The transmitter includes a microprocessor adapted to effect transmission of a unique tone identifying the transmitter. The receiver includes an omnidirectional and a yagi antenna switchable to a tuned RF amplifier, mixed with a frequency doubled crystal oscillator local oscillator signal, filtering, processing to retrieve any unique identifying tone, and signal strength detection and indication means. The transmitters are worn by sailors and the receiver is located on a vessel. The receiver is operable to monitor for any signals of a transmitter worn by a sailor fallen overboard using the omnidirectional antenna and sound a siren in the event of reception of such a signal. A sailor operating the receiver can switch to use the yagi antenna and using the signal strength indication means determine and monitor the direction of an overboard sailor relative to the vessel.
Abstract: A method and apparatus for determining stream weights is provided herein. During operation, an uplink direction of arrival (DOA) and a downlink direction of departure (DOD) calibration procedure is implemented using uplink signals and GPS information from a subset of mobiles without the need of calibration circuitry at the base. Because the presented calibration procedure needs no new hardware it can be deployed in existing deployments with only a soft-ware upgrade.
Abstract: An advanced multiple-beam GPS receiving system is achieved that is capable of simultaneously tracking multiple GPS satellites independently, detecting multiple interference signals individually, and suppressing directional gain in the antenna pattern of each beam in the interference directions. The GPS receiving system can be used for both planar and non-planar receiving arrays, including arrays that are conformally applied to the surface of a platform such as an aircraft. The GPS receiver combines spatial filtering and acquisition code correlation for enhanced rejection of interfering sources. Enhanced gain in the direction of GPS satellites and the ability to shape the beam patterns to suppress gain in the direction of interfering sources make the GPS receiving system largely insensitive to interfering and jamming signals that plague conventional GPS receivers.
Abstract: The disclosed system and method for determining direction-of-arrival generally includes an antenna element and a processor. The antenna element may configured to generate a signal in response to an electromagnetic wave. The processor may be process the signal to determine the direction-of-arrival of the electromagnetic wave. Further, the direction-of-arrival may be determined based on an estimate of the direction-of-arrival of at least one of the electric field and the magnetic field of the electromagnetic wave.
Abstract: A method and system for locating and positioning using broadcast frequency modulation (FM) signals, is provided. One implementation involves receiving FM stereo signals from three FM stations at one or more receivers, each stereo signal including a modulated 19 KHz FM pilot tone; and determining a geographical position at each receiver based on the phase difference of the demodulated pilot tones in the received FM signals.
Abstract: Provided are a device and a method that can classify an incoming wave and can correctly distinguish the position of an originating device, even in a multipath environment. A principal vertically polarized wave arrival direction sensing unit (104-1) and a principal horizontally polarized wave arrival direction sensing unit (104-2) respectively sense the arrival direction of a principal wave by sensing the arrival direction in which the maximum reception level is obtained. An incoming wave classifying decision unit (108) determines that a direct wave has arrived when the difference between the principal wave arrival direction sensed by the principal vertically polarized wave arrival direction sensing unit (104-1) and the principal wave arrival direction sensed by the principal horizontally polarized wave arrival direction sensing unit (104-2) is within a prescribed threshold value, and determines that a direct wave has not arrived when the difference is greater than the threshold value.
Abstract: A device for estimating a direction-of-arrival of a radio wave, the device comprising an array antenna including a plurality of antenna elements for receiving a high frequency signal, a demultiplexer for demultiplexing the received high frequency signal for each of the plurality of antenna elements to generate a plurality of frequency component signals and a direction estimating unit for estimating the direction-of-arrival of the radio wave by using two or more of the plurality of frequency component signals which are contiguous in a frequency direction.
Abstract: In a geo-security system, a device receives RF signals from multiple distinct classes of RF communication systems and extracts location-dependent signal parameters. A current geotag is computed from the parameters by fuzzy extractors involving quantization of the parameters and Reed-Solomon decoding to provide a reproducible unique geotag. The current geotag is compared with a stored geotag, and a geo-secured function of the device is executed based on the result of the comparison. The use of multiple signal sources of different types, combined with special fuzzy extractors provides a robust geotag that allows both lower false rejection rate and lower false acceptance rate.
Type:
Application
Filed:
January 25, 2010
Publication date:
July 28, 2011
Inventors:
Di Qiu, Sherman Lo, David S. De Lorenzo, Dan Boneh, Per Enge
Abstract: The present invention relates to a method and a system for determining the direction of arrival of one or multiple radio or acoustic waves and, more particularly, to such a method and system especially advantageous in situations where the number of available observations is small and/or the available observations are received with low power. The method significantly improves the performance of traditional subspace signal processing algorithms in the low sample size regime. The algorithm is specifically designed to provide consistent estimates even when the observation dimension has the same order of magnitude as the number of observations. This guarantees a good behavior in finite sample size situations, where the number of sensors or antennae and the number of samples have the same order of magnitude or in scenarios where the received signal power is not sufficiently high to guarantee detection via conventional one-dimensional search methods.
Type:
Grant
Filed:
March 9, 2006
Date of Patent:
July 19, 2011
Assignee:
Fundacio Privada Centre Technologic de Telecomunicacions de Catalunya
Abstract: A system to determine a direction of arrival of each of a plurality of constituent signals of a superimposed wave includes a tripole radio antenna, a sampling unit, a frequency determining unit, an amplitude and phase determining unit, and a direction determining unit. The sampling unit is configured to periodically sample an output of the tripole radio antenna to generate at least two samples. The frequency determining unit is configured to determine frequencies for each dimension of the constituent signals by performing a unitary matrix pencil method on the at least two samples. The amplitude and phase determining unit is configured to determine x, y, z amplitudes and x, y, z phases for each constituent signal using the determined frequencies. The direction determining unit is configured to determine a direction of arrival for each of the constituent signals from the determined frequencies, amplitudes, and phases.
Type:
Grant
Filed:
April 17, 2009
Date of Patent:
July 5, 2011
Assignee:
International Business Machines Corporation
Inventors:
Alain Biem, Lars Kristen Selberg Daldorff, Deepak Srinivas Turaga, Olivier Verscheure
Abstract: Method of high-resolution direction finding to an arbitrary even order, 2q (q>2), for an array comprising N narrowband antennas each receiving the contribution from P sources characterized in that the algebraic properties of a matrix of cumulants of order 2q, C2q,x(l), whose coefficients are the circular cumulants of order 2q, Cum[xi1(t), . . . , xig(t), xiq+1(t)*, . . . , xi2q(t)*], of the observations received on each antenna, for cumulant rankings indexed by l, are utilized to define a signal subspace and a noise subspace.
Abstract: The invention provides a determination of direction to a remote object which omnidirectionally transmits a signal. The invention includes a handheld directional and omnidirectional antenna at a user's location and a handheld circuit coupled to the antennas to determine field strengths of the signal received from the remote object by the two antennas. A comparison of the received signals at the antennas during a sweep a field of observation is made and a probable direction of the remote object relative to the user's location is selected from the data sweep. The apparatus may further comprise a digital compass which generates a compass heading corresponding to each direction in which the directional antenna is pointed. The circuit stores field strength data by compass heading and averages the field strength data according to a predetermined protocol over compass headings.
Type:
Application
Filed:
March 12, 2008
Publication date:
June 9, 2011
Applicant:
COMPASS AUTO TRACKER LLC
Inventors:
James Ladd Bernsten, Patrick Edward Franz, Bruce Hampton Kennard, Rob Baranowski, Ian Crabtree
Abstract: In a system for determining the angle of arrival of a target signal received by an array of antenna elements, a receiver obtains observations of a received target signal from an array of antenna elements; and a computer processes the obtained observations of the target signal with estimates of a target signal for different angles of arrival of a target signal received by the array of antenna elements to determine that the angle of arrival of the target signal is an angle of arrival at which dissimilarity between the observations of target signal and the estimates of the target signal for the different angles of arrival is minimized.
Abstract: An adaptive antenna radio communication device comprises a divided band direction estimating unit for estimating the direction by calculating the cross correlations between a pilot signal and sub-carrier signals of the respective divided bands received by an array antenna and calculating a spatial profile from correlation matrices determined by combining the correlation values between antenna elements of the different sub-carriers according to the output of the cross correlation calculation; a divided band array weight creating unit for creating a weight of a receive array having a directional beam in the direction of estimation for each divided band; and a sub-carrier directivity creating unit for creating a directivity by multiplication-combining the created receive array weight with the corresponding sub-carrier signal.
Abstract: Within a local region, information may be communicated between two or more wireless multimode communication devices (WMCD) comprising 60 GHz band and lower frequency band wireless interfaces. Spatial relationships between devices may vary. The 60 GHz interface may handle location determination operations and data transfers. The lower frequency band may support WPAN, WLAN and may handle coordination of communications and data transfers. The WMCDs may be coupled with a network. Antennas may be directional. Moreover, the spatial orientation of the antennas may be dynamically modified or swept across a specified angle. Furthermore, intelligent and/or adaptive antenna systems may be utilized. The WMCDs may utilize a position and/or time reference system to aid in location determination operations.
Abstract: Using in-phase and quadrature components of a received signal, spatial and temporal information is utilized to generate a maximum likelihood coefficient from the measured data to geolocate an emitter of unknown frequency. In one embodiment an iso-Doppler contour is generated having regions of high correlation to estimate location in which the maximum likelihood calculation uses two factors, one derived from a single aperture and one derived from bearing estimates, with the region of highest correlation corresponding to emitter location. Hypothesized in-phase and quadrature signals corresponding to an emitter location describe what the signals received at the aperture should be if the emitter is of a predetermined frequency and at a predetermined location, with these estimates used in the maximum likelihood algorithm.
Abstract: An RF signal detection process by incorporating direction detection of the RF signal along with energy detection to arrive at a signal of interest (SOI). The SOI is identified by matching direction detections and energy detections. Low-level and noise-like signals can be reevaluated for unresolved direction detections or energy detections. The RF signal detections can be filtered based on valid direction detections very early on in the processing chain to reduce the amount down-stream processing required.
Abstract: A method and apparatus for estimating location of wireless stations in a wireless communication network are provided. An estimation of a bearing angle of a wireless station from a reference point of a multi-beam antenna pattern is made based on a plurality of beaming angles of a multi-beam antenna pattern and a received signal property, at the wireless station, of each of a plurality of wireless signals transmitted on respective beams of the multi-beam antenna pattern for each of the plurality of beaming angles.
Abstract: The present invention provides a method of source number estimation based on eigenspace in DOA estimation, including: (1) obtaining signals received by uniform linear array; (2) calculating a covariance matrix according to the received signals; (3) calculating a complex-valued covariance matrix or a covariance matrix after real-valued computations; (4) conducting eigendecomposition to the covariance matrix to obtain its eigenvector matrix; (5) calculating a source number decision based on the eigenvector; (6) calculating a ratio; and (7) source number estimation. The present invention can accurately estimate source number and save huge amounts of computation during signal processing in DOA estimation, and lower the cost of hardware.
Type:
Grant
Filed:
March 19, 2008
Date of Patent:
January 25, 2011
Inventors:
Weiqing Zhu, Jun Hu, Xiaodong Liu, Zhiyu Liu, Feng Pan
Abstract: Techniques are disclosed that allow for the detection, identification, and direction finding of wireless emitters in a given multipath environment. For example, the techniques can be used to detect and identify a line of bearing (LOB) to an IEEE 802.11 emitter in a building or in an open field or along a roadside. In some cases, multiple LOBs can be used to geolocate the target emitter if so desired. The techniques can be embodied, for instance, in a handheld device that can survey the target environment, detect an IEEE 802.11 emitter and identify it by MAC address, and then precisely determine the LOB to that emitter. In some cases, a sample array of response data from the target emitter is correlated to a plurality of calibrated arrays having known azimuths to determine the LOB to the target emitter.
Type:
Application
Filed:
June 18, 2009
Publication date:
December 23, 2010
Applicant:
BAE SYSTEMS Information And Electronic Systems Integration Inc.
Inventors:
Peter Dusaitis, Tyler Robinson, John J. Kelly, Joseph Warner
Abstract: Methods and systems for scanning RF channels utilizing leaky wave antennas (LWAs) are disclosed and may include configuring a receiving angle of a plurality of LWAs in a wireless device to receive RF signals at a desired starting angle. The receiving angle may be swept while measuring RF signal strength. A location of RF signal sources may be determined based on the measured RF signal strength and corresponding angle of reception. A resonant frequency of the LWAs may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The LWAs may be configured so that they are situated along a plurality of axes in the wireless device. The LWAs may comprise microstrip or coplanar waveguides, where a cavity height of the LWAs is dependent on spacing between conductive lines in the waveguides. The LWAs may be integrated in integrated circuits, integrated circuit packages, and/or printed circuit boards.
Abstract: Systems and methods are presented for passive location of transmitters in which two or more receivers time stamp received signals from target transmitters and the time stamped data for each target signal of interest is isolated to identify a peak power time of arrival for the signal at each transmitter from which differential scan observation values are derived, and for each signal of interest a line of position curve is computed based on the differential scan observation value and corresponding receiver locations, and for each signal of interest an estimated target transmitter location is determined based on an intersection of two corresponding line of position curves.
Type:
Application
Filed:
June 9, 2009
Publication date:
December 9, 2010
Applicant:
The Government of the US, as represented by the Secretary of the Navy
Inventors:
Jay W. Middour, Kelia Bynum, Christopher Huffine, Anthony D'Agostino, Charles Chrisman, C Lane Ellis, Randolph L. Nichols
Abstract: An arriving direction estimating device for estimating the arriving direction of an arriving wave with high accuracy and at high speed by using a sensor array. The arriving direction estimating device comprises a receiving section for generating a baseband signal from the arriving signals received by sensors, a matrix creating section for creating a spatial average covariance matrix R by combining the correlation vector of the baseband signal, a projection matrix creating section for creating a projection matrix Q from the matrix R depending on the number of signals of the arriving signals, a scale matrix creating section for creating a scale matrix S from a partial matrix of the matrix R, and an estimating section for estimating the arriving direction of the arriving wave from the angle distribution or an algebraic equation by using QS?1QH defined using the projection matrix Q and the scale matrix S.
Abstract: Method of using one or more transmitters and/or one or more parameters associated with a transmitter by using a reception station comprising a device suitable for measuring over time a set of K parameters dependent on the transmitters associated with vectors {circumflex over (?)}k representative of the transmitters for 1?k?K. The method includes a step of extracting the parameter or parameters consisting in grouping together by transmitter the parameters which are associated therewith by means of a technique of independent component analysis.
Abstract: Angle of arrival and/or range estimation within a wireless communication device. Appropriate processing of communications received by a wireless communication device is performed to determine the angle of arrival of the communication (e.g., with respect to some coordinate basis of the wireless communication device). Also, appropriate processing of the communications may be performed in accordance with range estimation as performed by the wireless communication device to determine the distance between the transmitting and receiving wireless communication devices. There are two separate modes of packet processing operations that may be performed: (1) when contents of the received packet are known, and (2) when contents of the received packet are unknown. The wireless communication device includes a number of antenna, and a switching mechanism switches from among the various antennae capitalizing on the spatial diversity of the antennae to generate a multi-antenna signal.
Type:
Application
Filed:
May 25, 2010
Publication date:
December 2, 2010
Applicant:
BROADCOM CORPORATION
Inventors:
Prasanna Desai, Brima B. Ibrahim, Siukai Mak