Abstract: Adaptive antenna beamforming may involve a maximum signal-to-noise ratio beamforming method, a correlation matrix based beamforming method, or a maximum ray beamforming method. The adaptive antenna beamforming may be used in a millimeter-wave wireless personal area network in one embodiment.

Abstract: A communications device for separating source signals provided by M signal sources includes an antenna array comprising N antenna elements for receiving at least N different summations of the M source signals. At least two of the N antenna elements are correlated and have different polarizations for receiving at least two of the N different summations of the M source signals, with N and M being greater than 1. A receiver is connected to the antenna array for receiving the at least N different summations of the M source signals. A blind signal separation processor is connected to the receiver for forming a mixing matrix comprising the at least N different summations of the M source signals, and for separating desired source signals from the mixing matrix. The mixing matrix has a rank equal to at least N.

Abstract: The present invention discloses a system and method for mitigating multipath in DSSS CDMA radio navigation signals by a) transmitting a rapid pulsing pattern from a transmitting device to a position receiver that samples the transmitted signal, b) separating the received samples and storing sample-based correlation accumulation values into independent bins that are synchronous with the received pulsing pattern, c) applying a logical decision process to determine the accumulation bin associated with the leading edges of the received pulses, and d) generating a range estimate from the correlation accumulation bin associated with the leading edges of the received pulses.

Abstract: A method for improving the results of radio location systems that incorporate weighted least squares optimization generalizes the weighted least squares method by using maximum a posteriori (MAP) probability metrics to incorporate characteristics of the specific positioning problem (e.g., UTDOA). Weighted least squares methods are typically used by TDOA and related location systems including TDOA/AOA and TDOA/GPS hybrid systems. The incorporated characteristics include empirical information about TDOA errors and the probability distribution of the mobile position relative to other network elements. A technique is provided for modeling the TDOA error distribution and the a priori mobile position. A method for computing a MAP decision metric is provided using the new probability distribution models. Testing with field data shows that this method yields significant improvement over existing weighted least squares methods.

Abstract: Disclosed is a method for improving accuracy of time measurement and a position tracking apparatus using the same. A method for improving accuracy of time measurement includes receiving a radio communication signal and obtaining timing information in a received signal; tracking a code that detects inconsistent timing between the received signal and a tracking signal generated for the received signal; storing history information on the inconsistent timing between the received signal and the tracking signal for each bit of the received signal; and arithmetically averaging the history information and updating the timing information of the received signal with the arithmetically averaged value.

Abstract: Methods and systems for detecting GNSS signals originating from an inauthentic source. A synthetic array using a receiver antenna which is randomly spatially translated may be used to gather alleged GNSS signals. The signals are then processed to determine the spatial correlation between them. A high spatial correlation between the signals indicates a probable inauthentic source for the GNSS signals.

Abstract: A receiver having an array antenna estimates arrival directions of multiple paths that arrive with an angular spread. Consequently, arrival direction estimation accuracy can be ensured without increasing throughput even if the power every path is low by estimating an average arrival direction of an entire set of multiple paths having the angular spread from a result of one angular spectrum by multiple correlation operation units that perform mutual correlation operations with pilot signals for baseband signals received by the array antenna, a path detection unit that detects multiple arrival path receiving timings by generating a delay profile based on output of each of the correlation operation units, a path correlation value synthesis unit that synthesizes a correlation operation value calculated in the multiple correlation operation units and an arrival direction estimation unit that collectively estimates multiple path arrival directions using output of the path correlation value synthesis unit.

Abstract: Systems and methods of correlating potential transmitters with received radio signals is provided. Image data is provided including paths traveled by potential transmitter. Potential transmitters are identified within the image data along with path segments traveled by potential transmitters. A first and second transmitter calculate certain parameters of received signals assuming that signals originated along the path segments. The calculated signal parameters are then compared to measured signal parameter to determine whether a transmitter is associated with a particular path.

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: A method and apparatus for performing blind signal separation in an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) system are disclosed. A transmitter generates a plurality of spatial streams of data and transmits the spatial streams via a plurality of transmit antennas. A receiver receives the transmitted spatial data streams with a plurality of receive antennas and generates a plurality of receive data streams. The receiver performs a discrete Fourier transform (DFT) on each of the receive data streams to generate a plurality of frequency domain data streams. The receiver then performs a blind signal separation on the frequency domain data streams to recover spatial streams transmitted by the transmitter. The blind signal separation may be performed by using an independent component analysis (ICA) in the complex domain. The blind signal separation may be performed individually for each OFDM subcarrier.

Abstract: Apparatus to determine the position of a user terminal, the apparatus having corresponding methods and computer-readable media, comprise: a receiver to receive at the user terminal an American Television Standards Committee Mobile/Handheld (ATSC-M/H) broadcast signal from a ATSC-M/H transmitter; and a pseudorange module to determine a pseudorange between the receiver and the ATSC-M/H transmitter based on the ATSC-M/H) broadcast signal; wherein the position module determines the position of the user terminal based on the pseudorange and a location of the ATSC-M/H transmitter.

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.

Abstract: A receiver having an array antenna estimates arrival directions of multiple paths that arrive with an angular spread. Consequently, arrival direction estimation accuracy can be ensured without increasing throughput even if the power every path is low by estimating an average arrival direction of an entire set of multiple paths having the angular spread from a result of one angular spectrum by multiple correlation operation units that perform mutual correlation operations with pilot signals for baseband signals received by the array antenna, a path detection unit that detects multiple arrival path receiving timings by generating a delay profile based on output of each of the correlation operation units, a path correlation value synthesis unit that synthesizes a correlation operation value calculated in the multiple correlation operation units and an arrival direction estimation unit that collectively estimates multiple path arrival directions using output of the path correlation value synthesis unit.

Abstract: A method for detecting a plurality of navigation beacon signals by using either two antennas or a synthetic aperture antenna for receiving a plurality of distinct measurements, and combining the plurality of distinct measurements using a plurality of antenna weight components to form an interference cancellation beam. In one embodiment, the plurality of antenna weight components is determined by eigenvalue processing. In another embodiment, the plurality of antenna weight components is determined by simplified processing. In another aspect, a single antenna is used for receiving an originally received measurement. A copy of the originally received measurement is made and processed to achieve the proper time delay to emulate spatial diversity. The originally received measurement and the processed copy are combined to form an interference cancellation beam.

Abstract: Some embodiments use scanning devices to characterize radio signals received at a number of locations within a geographical area of interest. The signal characteristics along with the location information associated with the characteristics are stored in a centralized reference database. A mobile device characterizes signals it receives at a certain location and compares the characteristics with the signal characteristics stored in the reference database to obtain accurate location information of the certain location.

Abstract: An adaptive antenna array control system and associated method is provided for continuously and automatically assigning resources to either protect against strong interferers or to shade a spatial region, reducing gain in that spatial region, to protect against potential low power interference, thus providing improved adaptive interference cancellation system performance with limited resources. The Array biasing system is provided as an element of an adaptive antenna array control loop.

Abstract: A method of determining the location of a mobile device is provided. The method receives a signal with a known radio transmission pattern at the mobile device from each of several transmitting devices. The method correlates each received signal with a corresponding signal that has a same known radio transmission pattern to determine the time the signal traveled between the corresponding transmitting device and the mobile device. The method determines the location of the mobile device based on the time the signal travelled between the corresponding transmitting device and the mobile device. In some embodiments, determining the location of the mobile device does not require calculating a distance between the mobile device and any of the transmitting devices. In some embodiments determining the location of the mobile device includes solving a function that is dependent on the time the signals traveled between each corresponding transmitting device and the mobile device.

Abstract: A method for determining a Doppler shift of a first signal is provided. First, a plurality of Doppler frequency hypotheses is combined to obtain a joint Doppler signal. The first signal is the correlated according to the joint Doppler signal and a plurality of code signals with phases corresponding to a series of code phase hypotheses to obtain a series of correlation results which are then examined to determine whether the Doppler shift does lie in the Doppler hypotheses. A fine Doppler search is then performed to determine the Doppler shift when the Doppler shift lies in the Doppler hypotheses.

Abstract: In a geolocation system for determining a geolocation of a target emitter, a method for determining the geolocation.

Abstract: A radar sensor receives a radar wave signal through a radome in each of antennas while judging existence of an attenuating thing in a detecting unit. This unit extracts a maximum level channel from receiving channels assigned to the antennas every modulation period, calculates a difference in signal level between the maximum level channel and each receiving channel every modulation period, sets each receiving channel corresponding to large level differences in one measuring period including plural modulation periods as a candidate channel every measuring period, increments a preliminary variable of each candidate channel every measuring period, increases a final variable each time the preliminary variable of at least one receiving channel reaches or exceeds a preliminary value in one measuring period, and judges in response to the final variable reaching a final value that the attenuating thing attenuates the radar wave directed toward the random.

Abstract: [Object] To provide an adaptive array control device, method, and program adapted to be able to output an enhanced target signal by precisely carrying out a coefficient update control of a plurality of signals input from a group of sensors arranged in an array, the coefficient update control being less influenced by the frequency characteristics of the signals and directions of a target signal and interference. [Achieving Means] The invention includes: a gain control section 900 having an analyzing section 903 which analyzes characteristics of a target signal and a correcting section 905 which corrects a target signal power estimated value in response to the analysis result; and blocking matrix circuits 310 and 320 which receive and process signals from a plurality of sensors having different intervals.

Abstract: A GPS communication system including a server and a client, each including a GPS receiver, for reducing the code phase search space of the GPS receiver of the client. The communication system includes a transmitter for transmitting timing information from the server to the client to help the client locate a first satellite, and a receiver for using timing differences between the satellites to synchronize and locate other satellites. The code phase search space is reduced by reducing the number of phase hypotheses that must be calculated to establish communication between the server and the client.

Abstract: An apparatus for localizing a position on a path, radio signals of fixedly positioned radio transmitters being receivable along the path, the apparatus including a determiner for determining properties of the radio signals of the fixedly positioned radio transmitters at the position, and a comparator for comparing the determined electromagnetic properties with previously recorded properties which characterize a reference path, and for determining a relation between the position and the reference path on the basis of a result of the comparison.

Abstract: A communications system includes multiple mobile wireless communications devices transmitting at a same time to a fixed receiver assembly. Each mobile wireless communications device transmits a source signal defined by a respective character set comprising a plurality of symbols. At least one of the symbols in the respective character sets is transmitted at a different power level so that the transmitted source signal from each mobile wireless communications device appears with linearly independent power level time periods. The linearly independent power level time periods are used by the fixed receiver assembly to populate a mixing matrix for signal separation processing.

Abstract: Method and apparatus for minimizing antenna backside signal response and ambiguity in low frequency applications, particularly low frequency synthetic aperture radar (SAR). Various time delay elements are selectably switched into the signal path so as to cause a null to be placed in the antenna response pattern in the direction of undesired radar returns. The means for selectably switching may be dithered so as to introduce modulation onto the undesired radar return to aid in the discrimination and removal of the undesired radar return from the SAR image during post processing.

Abstract: In an environment of spatially correlated additive noise, the direction estimation apparatus for coherent signals calculates (M?q?1) instantaneous cross-correlations between some array data, and selecting multiple pairs each of which is consisted of p instantaneous correlations from the (M?q?1) instantaneous cross-correlations to form a Hankel correlation matrix, where a length of a spatial correlation in terms of antenna elements is assumed to be q. Next, the apparatus divides that Hankel matrix into an upper submatrix and a lower submatrix, and then calculates a linear operator at time n by using the adaptive LMS algorithm with a fixed or time-varying step-size parameter. Then a noise subspace is estimated from that linear operator. Finally the directions of incident signals at a predetermined time is estimated and tracked by using that noise subspace with Newton approximation.

Abstract: In a network-based Wireless Location System (WLS), geographically distributed Location Measurement Units (LMUs) must be able to detect and use reverse channel (mobile to network) signals across multiple BTS coverage areas. By using Matched Replica correlation processing with the local and reference signals subdivided into discrete segments prior to correlation, the effects of mobile clock drift and Doppler shifts can be mitigated allowing for increased processing gain.

Abstract: A sparsely populated array of antenna elements on a plane is provided such that the angle of arrival (AoA) measurement for a radiofrequency signal received by the array has high resolution and is non-ambiguous within a 360-degree azimuthal field of view. The array comprises a two-dimensional antenna array developed using fuzzy genetic logic based on specified criteria. In response to one specified set of criteria, the array comprises having a first large element formation combined with a second smaller element formation. The first large element formation supports high DF accuracy while the second smaller cluster facilitates ambiguity resolution.

Abstract: A method is provided for constructing a histogram to represent the root-mean-squared phase differences for a signal received at pairs of elements in an array. A pair-wise element phase difference (“PEP”) between a signal received at an angle of arrival ?1 and a signal received at an angle of arrival ?2 are determined. The difference ?? between the differential phase measurements at ?1 and ?2 is computed. The process is repeated for all unique pairs of angles (?1, ?2) from 0 to 359 degrees and the results are summed over all PEPs to calculate the root mean squared phase difference ?{square root over (??2(?1,?2))} between two different angles of arrival ?1 and ?2. A two-dimensional histogram is created by pairing the measurements ?{square root over (??2)} and ??, where ??=?2??1.

Abstract: An object of the invention is to provide a receiving apparatus in which multipath noise can be reduced. In a diversity receiving apparatus (20), a delay amount of phase shifters (24a, 24b) is changed to reduce a multipath level (Mdc) detected by a multipath detecting unit (33). The multipath detecting unit (33), signal processing parts (23a, 23b), and a combiner (25) are provided to obtain a received signal based on received outputs of a plurality of antennas (21a, 21b) when receiving a radio wave signal modulated by a modulating method, such as an FM, in which no change in amplitude is produced. Therefore, the radio wave signal can be received in a better condition than when received using a single antenna. The multipath detecting unit (33) detects a change in amplitude of the received signal as the multipath level (Mdc).

Abstract: An adaptive array antenna apparatus for performing adaptive control based on received signals received by a plurality of antenna elements which form an array antenna. The apparatus includes a computation part for computing an error of the received signals at different timings; an error comparison part for comparing the errors at the different timings with each other; and a weighting synthesizing part for performing weighting synthesis based on results of the comparison. Based on the results of the comparison, the computation part releases at least a part of computation resources required for the computation of the errors, and terminates the computation of the errors. Typically, the computation part performs the release of the computation resources when it is determined that the error has a minimum value, and terminates the computation of the errors.

Abstract: A system and method for detecting and locating a radio frequency emitter. A number, N, of receiving units using the same bandwidth, center frequency, and measurement time duration receive signals from the emitter. Higher Order Statistics (HOS) are used to calculate a correlation function between the received signals using one of the received signals as a reference. Results of the correlation function are used to form volumes of probabilities in a subset of an N?1 dimensional space of information regarding the location of the emitter. Each correlation function result in the subset corresponds to a single point in physical space.

Abstract: Embodiments of the present invention include a method of determining a location of a mobile device. The method comprises transmitting a signal between a plurality of known locations and receiving signal at device of unknown location such as a mobile device. The signal may include multiple tones having different frequencies and resulting in sets of residual phase differences. The location of the mobile device may be determined using the known locations and the frequency and phase differences between the transmitted tones. In one embodiment, OFDM signals may be used between an access point and mobile device, for example, to determine the location of the mobile device.

Abstract: A system and methods for calculating a range to a turbulent air region from an antenna platform is disclosed. The methods determine a correlation lag value corresponding to a time shift in receiving propagation of an interference pattern traveling along a path that is subject to the turbulent air region at antennas responsive to incident electromagnetic energy. Based upon the correlation lag value, the methods calculate the range to the turbulent air region from the antenna platform and issue a warning that indicate the range.

Abstract: The invention relates to one or more methods for locating a shopper's, associate's, manager's or vendor's presumed position in a store using a communication multi-network for communication in the store. Specifically, at least one location device is positioned in proximity to, for example, a shopper such that the shopper's presumed position about the store may be known continuously or upon demand to the store.

Abstract: A radar sensor receives a radar wave signal through a radome in each of antennas while judging existence of an attenuating thing in a detecting unit. This unit extracts a maximum level channel from receiving channels assigned to the antennas every modulation period, calculates a difference in signal level between the maximum level channel and each receiving channel every modulation period, sets each receiving channel corresponding to large level differences in one measuring period including plural modulation periods as a candidate channel every measuring period, increments a preliminary variable of each candidate channel every measuring period, increases a final variable each time the preliminary variable of at least one receiving channel reaches or exceeds a preliminary value in one measuring period, and judges in response to the final variable reaching a final value that the attenuating thing attenuates the radar wave directed toward the radome.

Abstract: The method and system provides an improvement in signal to noise plus interference without utilizing a calculated covariance matrix or calibrated antenna array, and does not require knowledge of the array geometry. The system utilizes the cross correlation of the output of each antenna element to estimate a weight vector for resolving a signal in a multiple simultaneous source environment.

Abstract: A beam-forming antenna for transmission and/or reception of an electromagnetic signal having a given wavelength in a surrounding medium includes a transmission line electromagnetically coupled to an array of individually controllable antenna elements, each of which is oscillated by the signal with a controllable amplitude. The antenna elements are arranged in a linear array and are spaced from each other by a distance that does not exceed one-third the signal's wavelength in the surrounding medium. The oscillation amplitude of each of the individual antenna elements is controlled by an amplitude controlling devices such as a switch, a gain-controlled amplifier, or a gain-controlled attenuator. The amplitude controlling devices, in turn, are controlled by a computer that receives as its input the desired beamshape, and that is programmed to operate the amplitude controlling devices in accordance with a set of stored amplitude values derived empirically for a set of desired beamshapes.

Abstract: An apparatus comprises a first sensor mounted on a first platform for sampling a first portion of a continuous waveform occurring in a time window and for producing a first signal sample, a second sensor mounted on a second platform for sampling a second portion of the continuous waveform occurring in the time window for producing a second signal sample, and a processor for determining time difference of arrival measurements and for applying a maximum likelihood estimation process to combine multiple time difference of arrival measurements between multiple pairs of platforms, to estimate the location of an emitter of the continuous waveform. A method performed by the apparatus is also provided.

Abstract: The subject matter disclosed herein relates to techniques for estimating a speed of an object that transmits a signal at a carrier frequency. An apparatus and method disclosed herein includes receiving at an array of multiple antenna elements a radio frequency signal transmitted by a moving object; and estimating a speed of said moving object based, at least in part, on a spatial cross-correlation among characteristics of signals received at individual ones of said multiple antenna elements.

Abstract: A method is disclosed for processing all types of received, interfering radio frequency signals corrupted by noise to extract the individual signals without having any a priori knowledge about them. Received signals are converted for eigenspace processing and are subjected to repeated non-linear time domain and fast Fourier transform frequency domain processing that calculates eigenstream beam forming weights U. By performing calculations in eigenspace, the number of independent weights U that must be calculated is generally reduced, minimizing calculating time. Once the weights U have been calculated in eigenspace they are transformed into antenna beam forming weights W that are used to extract the individual signals and to determine the angle of arrival of each of the individual signals. Further time is saved because the weights W do not have to be updated for every time slice of the received signals.

Abstract: [Object] To provide an adaptive array controlling method, a device, and a program, and an adaptive array processing method, a device, and a program, which are less influenced by frequency characteristics of input signals and directions of a target signal and interference, and capable of performing accurate coefficient update. [Achieving Means] A device includes: a pair of array processing sections 330 and 340 in which a gain is non-zero with respect to a target signal, and a phase difference in processing results with respect to interference becomes close to 180 degrees; and a correlation calculation section 920 which calculates correlation between their outputs.

Abstract: An image processing system, for correlating shapes in multi-dimensional images including image data processor for estimating a similarity measure including estimating two image signals representing shapes defined in respective windows in two multi-dimensional images using a Hermite Transform applied to both the image signals for performing an evaluation of two first sets of scalar valued Hermite coefficients from which a combination yields a transformed set of scalar valued Hermite coefficients {KI}. The inverse Hermite Transform is applied to the transformed set of scalar valued Hermite coefficients to achieve the computation of a windowed correlation function. The maximum of the windowed correlation function is estimated as the wanted similarity measure to correlate the shapes. The correlated shapes and/or processed images are displayed.

Abstract: The present invention discloses a beam-forming method for realizing interference suppression, comprising steps of: a. performing channel estimation for an expected user signal and interference signal in signals received by an array antenna and obtaining array channel impulse responses of the expected user signal and the interference signal respectively; b. obtaining array correlation matrixes of the expected user signal and the interference signal respectively according to the array channel impulse responses obtained in step a; c. obtaining a new array correlation matrix of the interference signal according to relation between the expected user signal with the interference and noise; and d. computing a beam-forming weighting coefficient of the array antenna according to the array correlation matrix of the expected user signal obtained in step b and the new array correlation matrix of the interference signal obtained in step c.

Abstract: A Doppler frequency searching method and correlator are disclosed. In the present invention, before Doppler frequency removal, a received signal is converted into digital form and the spreading code is removed. Then the signal is down-sampled to have a low sampling rate, which can be determined according to the maximum Doppler frequency to be searched. The Doppler frequency searching is done by stages. Each stage is in charge of a portion of the Doppler frequency to be removed. The sampling rate can be further reduced in each stage. Each stage can have a plurality of Doppler frequency removal units sharing the portion of Doppler frequency that the stage is to remove. Power consumption is reduced since Doppler frequency removal is executed with low sampling rate.

Abstract: [Object] By enabling accurate coefficient update, a high-quality array processing output which is less influenced by frequency characteristics and incoming directions of input signals control can be acquired, irrespective of the frequency characteristics and incoming direction of the input signals. [Achieving Means] Identification information of a target signal and interference by amplitude is corrected according to identification information of the target signal and the interference by phase, and with use of the correction result, identification of the target signal and the interference is performed. More specifically, an identification information generation section according to phase, a correction signal generation section, and a correction section are provided.

Abstract: A method for processing an array antenna signal is disclosed, comprising steps of: a. determining the number of antenna units participating the processing of the array antenna signals and selecting antenna units to participate the array antenna signal processing from all the antenna units in the array antenna; b. performing signal estimation processing on received signals by all the antenna units selected in step a and obtaining a user feature parameter estimation; c. performing estimation of weight coefficients for all the antenna units of the array antenna based on the user feature parameter estimation obtained in step b; and d. receiving and/or transmitting the array antenna signals based on the weight coefficients estimated in step c. The method of the present invention can effectively reduce a computation amount of the array antenna signal processing and improve a reliability of a received signal.

Abstract: Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals.

Abstract: A method and an apparatus is disclosed for efficient cross correlation of a plurality of signal vectors. Incoming data is partitioned into several segments and processed according to an algorithm where data rotation is a function of post-correlation memory size.

Abstract: The present invention provides a method of determining a plurality of beamforming weights for application to multicast transmission to a plurality of users by a corresponding plurality of antennas associated with a base station. One embodiment of the method includes determining a covariance matrix associated with the plurality of users. The covariance matrix is determined based on a channel matrix and a noise-plus-interference vector associated with each user. The method also includes determining the plurality of beamforming weights based on a gradient of the covariance matrix associated with a selected one of the plurality of users and storing the plurality of beamforming weights.