1456 results about "Direction of arrival" patented technology

There is disclosed a radio communication system in which a constitution of a base station and further a control station can be simplified. A radio communication system according to the present invention converts a received signal received by a plurality of antenna elements in a base station to a signal of different frequency band, and then conflates the converted signal in order to generate sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then the optical signal is transmitted to a control station via an optical fiber. Or the control station performs weighting to phase of the transmitted signal transmitted from a plurality of antennas of a base station, and then performs frequency conversion to different frequency band, and then conflates the converted signal in order to generate the sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then an optical signal is transmitted to the base station side via the optical fiber. The control station and the base station divides the received sub-carrier wave multiplex signal by each frequency band, and then the frequency of the divided signals are converted to the same frequency band in order to generate the transmitted / received signal of each antenna element. By such a constitution, it is possible to reduce constituent of the optical transmission components to the minimum and to simplify the constitution of the base station. Furthermore, it is possible to maintain the relative phase difference and the relative intensity of the transmitted / received signal of each antenna element. Because of this, it is possible to estimate an arrival direction of the received signal and to control radiation beam pattern of the transmitted signal.

A system is provided for locating a vehicle. The system comprises a transmission device such as a key fob for transmission and receiving of a signal. Typically the key fob has a plurality of indicators such as LED indicators arranged in a circle. The key fob is adapted to transmit a radio frequency or microwave frequency transmission signal. An antenna array is positioned on or in a vehicle. The array comprises a plurality of antennas, generally arranged in a circular pattern. The array is adapted to receive the transmission signal from the transmission device which is converted to be analyzed by a microcontroller unit (MCU). The MCU is adapted to: (i) receive digital data converted from the transmission signal, (ii) calculate an angle of arrival (AOA) or direction of arrival (DOA) based on known components and an algorithm, and (iii) transmit a selection signal back to the key fob. A signal processing unit is coupled to the plurality of antennas and the MCU. The signal processing unit is adapted to receive the signal transmission from each antenna, convert the signal to digital data, and transmit the digital data to the MCU.

A radar-based physiological motion sensor is disclosed. Doppler-shifted signals can be extracted from the signals received by the sensor. The Doppler-shifted signals can be digitized and processed subsequently to extract information related to the cardiopulmonary motion in one or more subjects. The information can include respiratory rates, heart rates, waveforms due to respiratory and cardiac activity, direction of arrival, abnormal or paradoxical breathing, etc. In various embodiments, the extracted information can be displayed on a display.

A system for indicating the relative direction of a target object or location as determined from the current position of a wireless communication device. The system employs Direction of Arrival determination using an antenna array for indicating the direction of a target device and includes facilities to activate a location-indicating transmission in a target device, the ability to request that a location-indicating transmission be activated in a remote target device, relevant information reception from a target device and the display of all potential target devices within effective transmission range of the wireless communication device.

Methods and systems for enabling the rectification of deteriorated channel conditions on a communication link are described. In particular, the methods and systems can employ mechanisms that prioritize beams in accordance with signal quality measures, direction of departures of transmission beams and / or direction of arrivals of reception beams to address variable channel conditions.

An electronic scanning type radar device mounted on a moving body includes: a transmission unit transmitting a transmission wave; a reception unit comprising a plurality of antennas receiving a reflection wave of the transmission wave from a target; a beat signal generation unit generating a beat signal from the transmission wave and the reflection wave; a frequency resolution processing unit frequency computing a complex number data; a target detection unit detecting an existence of the target; a correlation matrix computation unit computing a correlation matrix from each of a complex number data of a detected beat frequency; a target consolidation processing unit linking the target in a present detection cycle and a past detection cycle; a correlation matrix filtering unit generating an averaged correlation matrix by weighted averaging a correlation matrix of a target in the present detection cycle and a correlation matrix of a related target in the past detection cycle; and a direction detection unit computing an arrival direction of the reflection wave based on the averaged correlation matrix.

There is disclosed a radio communication system in which a constitution of a base station and further a control station can be simplified. A radio communication system according to the present invention converts a received signal received by a plurality of antenna elements in a base station to a signal of different frequency band, and then conflates the converted signal in order to generate sub-carrier wavemultiplex signal. The signal is converted to an optical signal, and then the optical signal is transmitted to a control station via an optical fiber. Or the control station performs weighting to phase of the transmitted signal transmitted from a plurality of antennas of a base station, and then performs frequency conversion to different frequency band, and then conflates the converted signal in order to generate the sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then an optical signal is transmitted to the base station side via the optical fiber. The control station and the base station divides the received sub-carrier wave multiplex signal by each frequency band, and then the frequency of the divided signals are converted to the same frequency band in order to generate the transmitted / received signal of each antenna element. By such a constitution, it is possible to reduce constituent of the optical transmission components to the minimum and to simplify the constitution of the base station. Furthermore, it is possible to maintain the relative phase difference and the relative intensity of the transmitted / received signal of each antenna element. Because of this, it is possible to estimate an arrival direction of the received signal and to control radiation beam pattern of the transmitted signal.

A telepresence video conference endpoint device includes spaced-apart microphone arrays each configured to transduce sound into corresponding sound signals. A processor receives the sound signals from the arrays and determines a direction-of-arrival (DOA) of sound at each array based on the set of sound signals from that array, determines if each array is blocked or unblocked based on the DOA determined for that array, selects an array among the arrays based on whether each array is determined to be blocked or unblocked, and perform subsequent sound processing based on one or more of the sound signals from the selected array.

A method of signal processing includes calculating a range based on information from a reflected ultrasonic signal. Based on the calculated range, one among a plurality of direction-of-arrival (DOA) estimation operations is selected. The method also includes performing the selected operation to calculate an estimated direction of arrival (DOA) of an audio-frequency component of a multichannel signal. Examples of DOA estimation operations include operations based on phase differences between channels of the multichannel signal and operations based on a difference in gain between signals that are based on channels of the multichannel signal.

The present invention relates to locating a person who is operating a wireless communications device in an indoor environment. In particular, it relates to processing various combinations of RSSI, direction of arrival and flight time characteristics of a signal, as received at two or more and preferably three or more access points. In one embodiment, the access points implement a wireless LAN (WLAN) and the communications device is a telephone operating over the WLAN. In another embodiment, the localization of a wireless device allows a system to reject users who are outside a predefined physical area.

A hybrid wireless network system is disclosed. The hybrid wireless network system includes an antenna array, an analog subsystem, and a digital subsystem. The antenna array at least includes two antenna elements. In the case of using multiple antenna elements to extend link range and coverage, a coarse-fine method is included for antenna elements selection. The analog subsystem calculates a difference signal and a sum signal based on the two RF signals. The analog subsystem includes step leveling devices. The digital subsystem estimates a direction-of-arrival (DOA) based on the sum signal and the difference signal. The step-leveling devices receive weights from the digital subsystem, in form of a feedback control, to apply the weights on the two RF signals respectively. The digital subsystem repetitively calculates new weights to update a beam pattern formed by the two RF signals until the DOA approaches null.

A radar-based physiological motion sensor is disclosed. Doppler-shifted signals can be extracted from the signals received by the sensor. The Doppler-shifted signals can be digitized and processed subsequently to extract information related to the cardiopulmonary motion in one or more subjects. The information can include respiratory rates, heart rates, waveforms due to respiratory and cardiac activity, direction of arrival, abnormal or paradoxical breathing, etc. In various embodiments, the extracted information can be displayed on a display.

A system and method for an arrayed sensor to resolve ambiguity in received signals, improve direction of arrival accuracy and estimate a location of one or more targets in an environment including signal interference.

In a detection and ranging apparatus that performs direction-of-arrival estimation using a sensor array and that enlarges an effective aperture using a plurality of transmitting sensors, adverse effects associated with time division switching are eliminated, achieving high-accuracy measurement. A transmitter wave is spread in modulators by using mutually orthogonal codes, and the resulting transmitter waves are radiated from two transmitting sensors. Signals received by receiving sensors are each split by a splitter into two parts, which are then respectively despread in a demodulator by using the same codes as those used in the transmitter.

Methods and apparatus are provided for determining a direction of arrival (DOA) (46) of a Radio Frequency (RF) signal (32) transmitted by a remote unit (22) in a wireless communication system (20). The methods comprise receiving the RF signal (32) with multiple antennas (34,36,38,40,42,44) of the antenna array (26) and determining a preliminary direction of arrival (DOA) (78) for the RF signal (32) received with the multiple of antennas (34,36,38,40,42,44) of the antenna array (26). The methods also comprise selecting a coefficient (80) for the antenna array (26) based at least in part upon the preliminary DOA 978), modifying the RF signal (32) with the coefficient (80) to generate a modified RF signal (82), and determining the DOA (46) of the RF signal (32) with the modified RF signal (82).

A beamforming device includes a Direction Of Arrival (DOA) estimation unit for estimating DOAs of the received signals based on a data subcarrier matrix; a pre-spatial filtering unit for using the estimated DOA, performing a filtering operation for the data subcarrier matrix, and generating filtering matrixes; a signal identification unit for using a data sequence, identifying original and interference signals, and generating the DOAs of the original and interference signals; a spatial filtering unit for generating an interference-plus-noise covariance matrix by using the DOA of the interference signal, eliminating the interference signal by using the covariance matrix and the DOA of the original signal, and forming final beams for the original signal; and a channel estimating and signal combining unit for performing a maximal ratio combining operation so that the final beams are combined as one combined final beam.

An apparatus having a coil of wire, energized by a repetitively pulsed radio frequency (RF) power source to provide electromagnetic fields to a region within a body. A scanning, directional hydrophone acoustically connected to the body, samples ultrasonic radiation generated by the RF fields at the RF frequency or twice the RF frequency induced from conductive spots. Signals from the hydrophone are analyzed with regard to their time of arrival relative to the RF pulses and with respect to their direction of arrival. These collected data are recorded and displayed as images of the spots within the region.

A mobile communication base station determines the oncoming direction of a radio wave with a simple arrangement and transmits a narrow angle beam in this direction. Received signals from a pair of wide angle beam antennae 21 - 1 and 21 - 2 having an equal configuration and a common orientation and which are located close to each other are fed to a direction finder receiver 22 and a communication receiver 15 . By utilizing the fact that the both received signals have a coincident amplitude, a phase difference between the received signals is detected. The oncoming direction of the received radio wave (or the direction of a mobile station) is determined on the basis of the phase difference. A beam switcher 12 is controlled so as to connect a transmitter 13 to a narrow angle beam antenna (one of 11 - 1 to 11 - 4 ) which is directed in the oncoming direction thus determined.

A “Sensor Array Post-Filter” provides an adaptive post-filter that accurately models and suppresses both diffuse and directional noise sources as well as interfering speech sources. The post-filter is applied to an output signal produced by a beamformer used to process signals produced by a sensor array. As a result, the Sensor Array Post-Filter operates to improve the signal-to-noise ratio (SNR) of beamformer output signals by providing adaptive post-filtering of the output signals. The post-filter is generated based on a generative statistical model for modeling signal and noise sources at distinct regions in a signal field that considers prior distributions trained to model an instantaneous direction of arrival for signals captured by sensors in the array.

A system and process for self calibrating a plurality of audio sensors of a microphone array on a continuous basis, while the array is in operation, is presented. In essence, the present microphone array self calibration system and process finds a set of corrective gains that provides the best channel matching amongst the audio sensors of the array by compensating for the differences in the sensor parameters. The present system and process is not CPU use intensive and is capable of providing real-time microphone array self-calibration. It is based on a simplified channel model, projection of sensor coordinates on the direction of arrival (DOA) line, and approximation of received energy levels, all of which speed up processing time.

The invention provides a microphone array voice enhancement device with a sound source direction tracking function and a method for the microphone array voice enhancement device. The microphone array voice enhancement device relates to voice signal processing. A microphone array, an adjustable parallel beam former group module, a fixed parameter FIR (Finite Impulse Response) filter module, a fixed parameter signal blocking module, an adaptive noise canceller module and a sound source direction update module are aranged in the devide. The method comprises the following steps of: initializing, forming an adjustable beam, fixing parameter filtering, blocking a signal, carrying out adaptive noise cancelling, and updating a sound source direction. The invention provides an adjustable parallel beam former group combined with a sidelobe canceller structure to achieve real-time tracking of a target sound source direction, embeds the sound source direction tracking function directly to a generalized sidelobe canceller structure, can achieve sound source direction tracking and voice enhancement, thereby overcoming sensibility of an algorithm performance on a DOA (Direction of Arrival) estimation error.

A radar apparatus includes an antenna that receives echo signals, each of the echo signals being a radar signal reflected by one or more objects; a Doppler-frequency acquirer that acquires Doppler frequencies at each range bin from the received echo signals; a direction correlation power-value calculator that calculates direction correlation power values for respective combinations of the Doppler frequencies and at least one of a distance to the one or more objects and an arrival direction of the echo signals, each direction correlation power value indicating a strength of a corresponding echo signal; and a normalized direction correlation-value calculator that calculates, for the respective combinations, normalized direction correlation values, each normalized direction correlation value indicating a probability of the arrival direction of the corresponding echo signal.

The invention provides a computer-implemented method for determining a time delay for time delay compensation of a microphone signal from a microphone array in a beamformer arrangement. For a given time, an instantaneous estimate of a position of a wanted sound source and / or of a direction of arrival of a signal originating from the wanted sound source is determined. The computer system then determines whether the instantaneous estimate deviates from a preset estimate of a position of the wanted sound source and / or of a direction of arrival of a signal originating from the wanted sound source according to a predetermined criterion. The predetermined criterion comprises a check whether the instantaneous estimate deviates from the preset estimate by at least a predetermined deviation threshold. If the predetermined criterion is fulfilled, the instantaneous estimate for the given time is set by the computer system as the preset estimate, and the computer system determines the time delay for time delay compensation of the microphone signal based on the instantaneous estimate.

The invention discloses an estimation method of a co-prime array DOA (Direction Of Arrival) angle based on sparse reconstruction, and mainly solves the problems that a prior art is higher in operand, less in identification information source amount and large in passive location evaluated error, and needs more priori knowledge. The method comprises the realizing steps of forming a co-prime array by an antenna receiver; obtaining observation data to spatial signal sampling; receiving data vectors by a virtual array element obtained by observation data; dividing spatial grids to form over-complete bases; receiving a spare relationship between the data vectors and the over-complete bases by the virtual array element to build a spare restraint equation; resolving the spare restraint equation by adopting a convex optimization method to obtain sparest resolution; drawing a magnitude spectrogram by a relative relationship between the sparest resolution and the spatial angle to obtain a DOA angle value. According to the method provided by the invention, the passive direction-finding precision and operating speed can be improved under a condition of low priori knowledge, the number of the recognized information source can be improved, and the estimation precision of a signal direction angle can be improved in a low signal to noise ratio, therefore the estimation method can be used for target reconnaissance and passive location.

Method for received signal strength-based direction-of-arrival location estimation for wireless target in an indoor environment is disclosed. The method can use just one DOA sensor node with three antennas, configured substantially in the center of a predetermined confined indoor space. Packet signals can be transmitted by DOA sensor node to the wireless target, and vice versa, where each packet comprising of a fixed sensor node cover range. RSSI values are obtained for the respective RSSI states received from the wireless target at incident angles φ using the triangular antenna array, a 1P2T switch, and a vector signal deconstructor (VSD). A location (θ, φ) of the localized object is calculated using a RSS-based DOA algorithm. A RSS to DOA localization system using the above method is also disclosed.

The invention provides a SRP-PHAT multi-source spatial positioning method. The method comprises the steps that the number and spatial positions of all microphones in a uniform circular microphone array are assumed to be unchanged in the data obtaining process at first, the isotropous microphones are evenly distributed on a circumference which has the radius r and is located on an x-y plane, the direction of arrival of a plane wave s is expressed by polar coordinates, the original point of the coordinate system is located on a circle center position of the circular array, multiple sound source signals are divided into non-overlapped time frequency point sets, each time frequency window contains only one movable source signal, and weak W orthogonal separation conditions are met; a Hamming window is selected, a controllable response power function is calculated and a target function is obtained through a SRP-PHAT algorithm, wave beams are controlled to carry out scanning in all the possible receiving directions, and the wave beams output the direction value with the maximum power to obtain the direction of a sound source, so that the DOA estimation of the multiple sound sources has the better separating performance in the strong noise and moderate reverberation acoustic environment, the real peak value is obviously outstanding, and high positioning precision is achieved.

The invention relates to a phased ultrasound locating method of the partial discharge of a transformer, which is used for monitoring and locating partial discharge faults. Phased array ultrasound sensors arranged at two different positions of the transformer are adopted to receive ultrasound broadband signals sent out by a partial discharge source, and an array model is formed; then a broadband focus algorithm in a broad-ban array signal processing algorithm is applied to convert broadband signals received by the two phased array ultrasound sensors into narrow-band signals, then a narrow-band direction finding algorithm is applied to respectively carry out direction of arrival (DOA) estimation on the two narrow-band signals, and finally a cross locating algorithm is applied to determine the concrete position of the partial discharge. Meanwhile, the invention also discloses a locating system. The invention can carry out on-line accurate locating on the partial discharge in the transformer; moreover, the used locating system has simple structure, and the method is simple and easy to apply.