Abstract: A satellite communication subscriber device includes a smart antenna for generating antenna beams for receiving signals from at least one satellite, and a receiver. The receiver includes a quality metric module for calculating a quality metric on the signals received by each antenna beam. A beam selector is coupled to the smart antenna for selecting the antenna beams. An antenna steering algorithm module runs an antenna steering algorithm for operating the beam selector for scanning the antenna beams, receiving the calculated quality metrics from the receiver for each scanned antenna beam, and comparing the calculated quality metrics. The algorithm selects one of the scanned antenna beams based upon the comparing for continuing to receive signals from the at least one satellite.

Abstract: Direction findings by radio comprises arraigning an array of antennas, to receive signals from emitters, selecting individual antenna signals using a first multipole switch and determining, antenna signal strengths. Individual antenna signals are also selected by mutipole switch, which routes a selected signal to a third multipole switch. The third switch switches a phase shifter into and out of an antenna signal path. An adder is employed to add an antenna signal in a first signal path extending via the first multipole switch to a different antenna signal in a second signal path extending via the second and third switches. This determines combined signal strengths between pairs of antenna signals, one of which either has or has not been relatively phase shifted depending on the third switch position. Covariance matrix elements are determined from signal strengths enabling emitter bearings to be derived.

Abstract: An antenna control interface is integrated with common integrated circuit components, such as radio transceiver or baseband modem signal processing control logic. The antenna control interface controls the operation of an adaptive antenna array used with wireless communication system devices.

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: A mobile broadband wireless system including at least two pairs of nodes arranged in a cluster, each pair coupled to form a link for wireless communication. Each node includes an RF transceiver with associated modem, an antenna array arrangement coupled to the modem and arranged for multiple concurrent transmissions, where each antenna has a beam pattern selected to improve quality of transmission, and a controller for controlling the transceiver, modem and antenna array arrangement for providing point to point communication. The controller allocates MIMO streams and modulation to different antennas in the antenna array arrangement, and implements at least one interference mitigation mechanism to minimize interference within the cluster during multiple concurrent transmissions. A method of wireless communication is also provided.

Abstract: Disclosed herein is a direction finding system including: a transmitter configured to generate a single carrier; a plurality of receivers, each of which has a receiving antenna; a phase comparison section configured to compare phases of signals received by the receivers to determine a phase difference between the received signals; and an information processing section configured to perform a computation process for direction finding based on the phase difference.

Abstract: In an environment of temporally and spatially uncorrelated white additive noise, the direction estimation apparatus for coherent signals calculates (M?1) instantaneous cross-correlations between some array data, and selecting multiple pairs each of which is consisted of p instantaneous correlations from the (M?1) instantaneous cross-correlations to form a Hankel correlation matrix. 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 and or using the adaptive NLMS algorithm from the two submatrices. Then a noise subspace is estimated from that linear operator. Finally the directions of incident signals at time n is estimated and tracked by using that noise subspace with Newton approximation.

Abstract: Embodiments of the present invention provide a method and apparatus for all-polarization direction finding. The method and apparatus generally include acquiring measurements at least partially corresponding to an emitted signal and generated utilizing a blind signal extraction algorithm, forming an all-polarization cost function utilizing the acquired measurements, and determining an angle of arrival for the emitted signal utilizing the formed all-polarization cost function. Such a configuration enables angles of arrivals to be easily determined for signals having any polarization without using a multiple signal classification (MUSIC) algorithm.

Abstract: In an environment of temporally and spatially uncorrelated white additive noise, the direction estimation apparatus for coherent signals calculates (M?1) instantaneous cross-correlations between some array data, and selecting multiple pairs each of which is consisted of p instantaneous correlations from the (M?1) instantaneous cross-correlations to form a Hankel correlation matrix. 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 and or using the adaptive NLMS algorithm from the two submatrices. Then a noise subspace is estimated from that linear operator. Finally the directions of incident signals at time n is estimated and tracked by using that noise subspace with Newton approximation.

Abstract: The electronic tag authentication device of the present invention authenticates the contents of an electronic tag attached to goods. The electronic tag authentication device comprises an antenna directivity change unit for changing the directivity of an antenna for transmitting/receiving electrical waves in order to authenticate the contents of the electronic tag.

Abstract: A method for antenna subset selection by joint processing in RF and baseband in a multi-antenna systems. Lt input data streams are generated in a transmitter for either diversity transmission or multiplexing transmission. These streams are modulated to RF signals. These signals are switched to the t branches associated with the t transmit antennas, and a phase-shift transformation is applied to the RF signals by a t×t matrix multiplication operator ?1, whose output are t?Lt RF signals. These signals are transmitted over a channel by t antennas. The transmitted signals are received by r antennas in a receiver. A phase-shift transformation is applied to the r RF signals by a r×r matrix multiplication operator ?2. Lr branches of these phase shifted streams are demodulated and further processed in baseband to recover the input data streams.

Abstract: The invention pertains to a method of positioning antennas with sectorization in a data transmission system. The method makes it possible to search, by successive approximations, for the sector of each antenna allowing optimal reception of the information. The search step is repetitive.

Abstract: A system for enhancing the performance of a wireless communication device (WCD) while executing a direction of arrival (DoA) estimation. The performance may be improved through device management, and may include the collection of information from one or more sensors installed within the WCD. The sensor information may initially be used to determine an appropriate configuration for the device. Further, the sensor information may also be used to affect the behavior of the device while performing the DoA estimation.

Abstract: In a device for measuring angular positions by using radar pulses and mutually overlapping beam characteristics of at least two antenna elements, a switchable phase shifter is provided in the signal path of at least one antenna element which is switchable in the time-division multiplexing between different phase states. For the radar received signals, an evaluation device is provided for the joint and especially simultaneous evaluation of signals of two antenna elements with the participation of antenna element, in whose signal path a switchable phase shifter is provided.

Abstract: A diversity antenna arrangement to reduce cost and the number of switching operations between different antennas includes an antenna changeover switch for switching between antennas, and an evaluation circuit for evaluating reception quality of a signal derived from a signal received from at least one of the antennas and conveyed to a receiving device via the antenna changeover switch. The evaluation circuit emits an evaluation signal based on the determined reception quality. A control device drives the antenna changeover switch based on the evaluation signal. A weighting device, using a first coefficient, weights the signal conveyed to the receiving device via the antenna changeover switch, and using a second coefficient, weights a signal received from at least one further antenna. A summing circuit adds the weighted signals. A regulating circuit generates the coefficients to minimize the temporal amplitude fluctuations of the composite signal, which is evaluated by the evaluation circuit.

Abstract: A method for determining direction of transmission using an antenna array having a number of panels is disclosed. Each panel is configured to receive signals. According to one aspect of the method, each of the panels is directed to receive signals from a transmitting node. For each panel, a first table having data representing received signal power difference between the panel and a first neighboring panel and a second table having data representing received signal power difference between the panel and a second neighboring panel are built. The panel with the maximum received power is identified. For the identified panel, a first gain table and a second gain table corresponding to its first and second neighboring panels are searched to identify a first transmission angle and a second transmission angle, if any. A transmission angle relative to the transmitting node is determined using the first and second transmission angles.

Abstract: A discrete three-dimensional receiving element has multiple sensors scattered over its surface to detect and locate a signal. The sensors facing the signal detect the signal, and a boundary line is drawn between the sensor which detect the signal and those which don't. The strength of signal may also be detected. A plane is drawn through the receiver element, and the direction of the signal is determined as generally perpendicular to the plane, in the direction of the sensors which are receiving the signal. Distance to the source may also be determined based on signal strength. The location of the signal source may be transmitted to a remote location, or the receiver may direct an electromagnetic beam toward the source to detect further information about the source.

Abstract: An array antenna is facilitates transmission of data with amongst fixed radio units. The array antenna includes a number of antenna panels arranged in an hexagonal shape, one or more array control elements controlling the antenna panels, and one antenna routing element controlling the one or more array control elements.

Abstract: An incoming radio wave is received by array antenna elements which constitute an array antenna, and the correlation between the received data of some array antenna elements is calculated to form a correlation matrix which is not affected by the additive noise at each antenna element. Then a noise subspace is obtained from the correlation matrix by a simple linear operation based on the partition of an array response matrix and is used to estimate the direction of signal (i.e., radio wave) impinging on the array antenna. Because the evaluation of all correlations between the array data received by array antenna elements is not needed, and the eigendecomposition process is avoided, the computational load of the proposed direction estimation technique is reduced, and the noise insensitivity is improved.

Abstract: A method for determining direction of transmission using an antenna array having a number of panels is disclosed. Each panel is configured to receive signals. According to one aspect of the method, each of the panels is directed to receive signals from a transmitting node. For each panel, a first table having data representing received signal power difference between the panel and a first neighboring panel and a second table having data representing received signal power difference between the panel and a second neighboring panel are built. The panel with the maximum received power is identified. For the identified panel, a first gain table and a second gain table corresponding to its first and second neighboring panels are searched to identify a first transmission angle and a second transmission angle, if any. A transmission angle relative to the transmitting node is determined using the first and second transmission angles.

Abstract: Apparatus and process for determining the position and heading or attitude of an antenna array are described based on radiating sources, preferably GNSS or other such satellite positioning systems. An optimum satellite is selected and the antenna array is “null steered” by combining the phase of the received signals to calculate a null or null angle that points toward the optimum satellite. The null will determine angle for elevation toward the optimum satellite and azimuth or heading. The heading is the azimuth of the (which may be actual or calculated) projection of the null vector to the satellite onto the Earth's surface. The actual location on Earth of the antenna array can be found and the antenna array azimuth with respect to the satellite can be determined. The null angle may be measured more precisely by dithering on either side to average out noise and then averaging the angle deviations to calculate the null angle.

Abstract: An actuator for a release device of a motor vehicle has a control acting on the release device and at least one actuator element sending a signal wireless to the control for triggering a release action of the release device. The actuator element is a momentary-contact pushbutton and is part of a passive receiver. The passive receiver has a passive antenna arranged in a resonance circuit that is closed by actuating the actuator element.

Abstract: A system for finding the instantaneous spatial azimuth and elevation of a source of radio signals employing phase digitizers to measure the phase of arrival of a radio signal on an array of antennas. The phase digitizers providing digital indication of the phase of arrival, enable the determination of the azimuth, and elevetion of a source of radio signal, utilizing simple digital subtraction methods.

Abstract: A method of determining the location of an unknown source 10 transmitting a signal to satellite relays 14 and 16 comprises receiving replicas of the signal from the relays at receivers 18. The receivers 18 also transmit and receive reference signals via respective relays 14 and 16. All signals are downconverted, digitized and correlated with one another in pairs using a correlation function including a term which compensates for time varying differential frequency offset (DFO). Compensation for time varying differential time offset or time dilation is achieved by replicating or adding to signal samples and applying phase corrections. This procedure enables a correlation maximum and associated measurement results to be obtained despite the effects of relay satellite motion which mitigate against this. Results are used in a prior art geometrical technique to locate the unknown transmitter.

Abstract: A system and method is provided for determining the position of a transmitter/receiver device (13) arranged anywhere in a space in relation to at least two transmitter/receiver devices (11, 12) arranged at defined positions in the space with regard to each other. At least three transmitter/receiver devices (11, 12, 13), which each have an antenna device with a number of antenna units (20, 26, 27) distributed in a defined manner on a spherical surface (17) and a signal generating device, of which two transmitter/receiver devices (11, 12) are at least temporarily fixed in a local co-ordinate space (16). The other transmitter/receiver device (13) is movable relative to these devices.

Abstract: In a method of co-operative radio direction-finding in transmission in a system of radio direction-finding for a radiocommunications system comprising one or more transmission sources or transmitters, the transmitted signal comprises a reference sequence formed by a sequence of symbols {Sk}, the receiver comprising at least one array of several sensors coupled to a radio direction-finder.

Abstract: An optical position and orientation determining system determines yaw, pitch, roll, lateral translation and longitudinal translation of a body with respect to a direction and intensity sensing receiver. The system comprises two energy beam emitters, mechanically mounted on a body, which illuminate the position sensing receiver. The energy beams are intermittently energized in a predefined fashion to enable the receiver and its associated signal porcessing means to determine the position and orientation of the body with respect to the receiver. The system can also be used to determine velocities and accelerations of the body relative to the receiver.

Abstract: The invention relates to an apparatus for tracking nonsynchronous satellites.

Abstract: The present invention is in general related to tracking of multiple targets by means of measurements by various sensors. In particular the invention provides procedures for track initiation during multiple target tracking by means of measurements from passive sensors. The invention defines a quality measure for each tentative new target, by which the tentative targets are sorted and selected. The calculation of the parameters of possible targets and their covariance are preferably performed in a recursive manner. The track initiation comprises the steps of creating strobe tracks, calculating strobe track crosses, selecting a strobe track cross as a probable target and creating a target track.

Abstract: A direction finder is provided that can measure the incoming angles of plural incoming signals without spatially moving antenna elements and can be used in outdoor mobile communication environments. The direction finder also can shorten the measurement time. An array antenna comprises plural antenna elements arranged at regular intervals. The received signal components due to the mutual coupling between the antenna elements are removed by multiplying time series signal groups by the inverse matrix of a coupling coefficient matrix of the array antenna. The time series signal groups are obtained by modulating signals received with the array antenna. The covariance matrix of the received signal group can be subjected to a movement averaging process in terms of the Vandermonde format.

Abstract: In a method for the precise angle determination of targets by means of a multiple unit antenna radar system, individual antenna patterns are generated in separate directions by at least three feeds (F−1, F0, F1) which are spatially offset with respect to one another and which illuminate a joint collimator (R). By simultaneous and phase-correct excitation of several of the feeds, at least two combination antenna diagrams are generated, by means of which the angle determination takes place. The intersecting points of the combination antenna diagrams, are situated in angle ranges in which the exact angle determination is desired.

Abstract: Two pairs of signals determinative of bearing to a transmitter are developed from two pairs of directional antennas. The signals, converted to digital form, are compared to each other to develop a result signal. The result signal is used to select a primary pair out of the original two pair of signals. The non-primary pair of signals are compared to each other to develop a binary sign bit. The primary signal pair, the result signal and the sign signal are applied to a table to develop a bearing quantity related to the bearing to the transmitter.

Abstract: The data-link and antenna selection assembly combines a group of conformal ntenna arrays with radio frequency (RF) detection, control and switching circuitry to provide up to 360 degrees of azimuth coverage for an aerial or terrestrial vehicle. The signal monitoring comprises signal detection and determination of signal frequency and strength. These are input to a switching controller which selects the best receive path and transmit path as a function of received signal frequency and strength. Use of conformal antenna arrays eliminates the requirement for cumbersome mechanical positioners.

Abstract: This disclosure deals with processing radio-frequency navigation signals, particularly Loran-C signals, from crossed loop antennas (H-field antennas) by shifting the signal phase from two loops to be in quadrature with respect to each other and adding them together to achieve omnidirectivity of the antenna pattern during the acquisition mode; using the stronger signal of the two during the cycle selection mode to determine the polarity of the received signals; and calculating the relative bearing angles on transmitting stations to determine, with measured bearing, the orientation of the loop antenna with respect to these stations.

Abstract: There is provided a method of rapid Received Signal Strength Indication (RSSI) of a time-dispersed signal having echoes (where the time dispersal represents a significant fraction or more of the transmitted symbol interval). It comprises a sliding correlation of a received signal against a known sequence or via channel sounding to obtain the time-dispersal function of the communications channel upon which the signal is transmitted and a summation of the squares of the quadrature components of the energies at relative maxima of the correlations (correlation peaks determined with reference to a threshold level) to integrate the energy defined by the correlation function to determine the energy present among the time-dispersed echoes utilizing the time-dispersal function.

Abstract: A directional antenna connected to a portable communications transceiver is adaptively directed towards a remote station in a communication system. The amount of RF power required by the portable device is significantly reduced, relative to a non-directional antenna. The operational period of the transceiver between battery recharges is therefore considerably maximized.

Abstract: An apparatus for determining a spatial angular reference to an emitter of RF signals, such as direction of arrival or angle of arrival, from phase measurements made between two antennas is described. The apparatus uses at least a pair of dual polarized antennas having non-parallel boresights. Like polarized outputs from the antennas produce phase information which is stored and then summed to remove bias error in favor of the sin (AOA) component, while the phase information from the like polarized antennas is also differenced producing a signal indicative of the bias error. It is shown that the bias error can be uniquely related to emitter angle and azimuth. The latter information is obtained without the need for making emitter frequency measurements.

Abstract: In a cellular mobile telecommunications system, a radio link control method provides each base station with an antenna whose directivity is adaptively controllable on a mobile station basis. The base station communicates with a plurality of mobile stations by using the same frequency at the same time. The base station selects, among transmitters/receivers thereof which are in communication, two transmitters/receivers using the same frequency, detects the main beam directions of antenna directivities thereof, and then compares a difference between the main beam directions and a predetermined threshold. If the former is smaller than the latter, the base station executes handover so as to replace the frequency being used by one of the transmitters/receivers with another frequency. The method allows a single base station to use the same frequency twice or more while preventing interference from occurring within the base station.

Abstract: This invention relates to a system to alert an aircraft pilot of the presence and general location of other aircraft that might constitute a collision threat to the pilot's aircraft. A first and second antenna on the upper paid lower surfaces of the aircraft each operate in first and second modes characterized by respective first and second directivity conditions. The first and second antennas directly receive pulse signals from a source in order to determine the relative time of arrivals and thus the relative altitude of the source to the aircraft. Analysis means compares amplitudes of responses in the first and second modes to provide an angle indicating signal without having to generate radio signals other than those already being generated by equipment in the other aircraft in response to ground ATC interrogation.

Abstract: A system and method for obtaining the bearing angle of radio frequency is utilized in a direction finding system to determine the signal of interest. The system utilized an adaptive interferometric processor to null out modulation occurring due to commutation between the antenna elements. Through this system the bearing angle can be determined accurately and efficiently.

Abstract: A direction finding system utilizing a single monopole/crossed slot antenna in combination with associated electronic circuitry. Each of the four ports of the antenna are connected to amplitude varying elements whose outputs are combined by a power combiner. A microcontroller stores the signal. The microcontroller also generates the signals which control the amplitude variation supplied by each of the amplitude varying elements. Two configurations of the amplitude varying elements are provided by predetermined settings within the microcontroller. The two settings are selected to configure the antenna on two distinct reception patterns, each with a predetermined angular offset from a reference direction. In operation the antenna will be configured for a first reception pattern. The signals received will be detected, quantified, and stored by the microcontroller which subsequently reconfigures the antenna for a second reception pattern.

Abstract: An interference suppression system for cancelling undesired signals recei through the mainlobe of an antenna as well as its sidelobes. The interference suppression system has a main channel input having high gain for receiving desired signals and undesired signals and forming a main channel waveform, and an auxiliary channel input having low gain for receiving desired signals and undesired signals and forming an auxiliary channel waveform. A control circuit senses the relative undesired signal power in the two channels and responds by switching the waveforms in the two channels between two inputs of an interference-reducing circuit according to whether sidelobe or mainlobe interference is present in the main channel.

Abstract: The technique to measure the frequency very accurately for electronic warfare (EW) applications, and is simple in hardware, and which can accomplish this goal with a signal with real data (in contrast to complex data). It uses a linear approximation between points to calculate zero crossings of an incoming signal. From these crossings, one can find the frequency very accurately using only one channel of data. The input signal is down converted and digitized with one A/D converter. The digitized data is used to find the zero crossing. The resolution of the zero crossing is limited by the clock cycle. Two uniformly digitized points around a zero crossing are used to find the time for the crossing. The device according to the invention will calculate the frequency very accurately using only one channel of data.

Abstract: An apparatus and method for measuring the angles of arrival of a pair of transmission signals relative to a fixed antenna pair simultaneously receiving the transmission signals based upon the phase difference between antennas for each signal and the frequencies thereof includes components for separately squaring the signals received by each antenna, filtering each squared signal for separating a high frequency band and a middle frequency band, first phase correlating high frequency band signals filtered from each squared signal for producing a sum signal of the phase differences between the antennas for received transmission signals, second phase correlating middle frequency band signals filtered from each squared signal for producing a difference signal for the phase differences of the transmission signals received by the antenna pair, determining the phase differences of the transmission signals received by the antenna pair from the sum and difference signals therefor, providing delayed middle frequency ban

Abstract: This invention relates to a system to alert an aircraft pilot of presence and general location of other aircraft that might constitute a collision threat to the pilot's aircraft. An antenna means operates in first and second modes characterized by respective first and second directivity conditions resulting in first and second gains for signals from a certain direction. Analysis means compares the amplitues of the first and second responses to produce an angle-indicating signal locating a potential collision threat without having to generate radio signals other than those already being generated by equipment in other aircraft in response to ground ATC interrogation.

Abstract: A direction sensitive energy detecting apparatus characterized by having a pair of energy receiving and transmitting devices of different polar characteristics and so disposed that they define together one end of a path in such a way as to be coincident with each other; with the sensor being adapted to give two first outputs at least one of which is variable as a function of the direction of the path and the detector having ratiometric means for generating a second output which is a function of the ratio of the two first outputs and is variable only in response to changes in direction.

Abstract: Direction finding apparatus comprising at least ten antenna channels for connection to respective antennae in use, at least five receiver channels each coupled to at least two different antenna channels constituting a group, and circuitry for receiving and comparing the outputs of the receiver channels to determine the angular location of the signal source; the arrangement being such that in use the antennae of each group of antenna channels have a sufficient angular separation such that only one is capable of detecting the signal source at one time, and the nearest neighboring antennae of each group are coupled to respective different receiver channels different from the receiver channel of that group.

Abstract: A phase reference navigation system and method employs a plurality of fixed narrow beamwidth antennas arranged to cover a predetermined angular sector and such that the patterns of adjacent antennas crossover one another at their half-power points. Each antenna radiates an RF carrier which is amplitude modulated by a reference phase signal and by one of two different frequency subcarriers. Adjacent antennas radiate different frequency subcarriers. Each subcarrier is frequency modulated by a variable phase signal which has a phase relative to the reference signal which corresponds to the direction of orientation of the antenna from which that subcarrier radiates. A receiver simultaneously receives the RF energy radiated by two adjacent antennas. Upon demodulation, the two variable phase signals are recovered and combined to produce a resultant signal which has a phase that varies as a function of angle between the two antennas.

Abstract: A system using two magnetic quadrupole antennas, two magnetic dipole antennas and means for processing the respective antenna signal outputs provides unambiguous estimates of elevation and polarization for an incident RF signal. The system uses an efficient procedure to process the signals from a small aperture array of fixed loop elements for the purpose of providing radio direction of arrival information that is free of intrinsic polarization error. The directional information is developed by performing a simultaneous arctangent operation on signals output from the antennas or as the measured phase difference between a quadrature summed quadrupole output and a quadrature summed dipole output compensated by a phase offset between the dipole antennas and the quadrupole antennas.

Abstract: Method and device in the antenna and receiving system of a radio theodolite, wherein the radio signal arriving from the transmitter of the object (31) to be measured is received by means of at least three antennas (1 . . . n-1) in the antenna field (AK) as well as by means of a reference antenna (n). The signals received from said antennas are passed to the receiving system, being controlled and selected by an antenna-selection switch (10a). By means of said system, the phase differences between the signals of different antennas are detected and measured, on the basis of which phase differences it is possible to calculate the angles of incidence (.alpha.,.epsilon.) of the signals on the basis of the known coordinates of location of the antennas in the antenna field (AK). In the method an outer reference antenna (n+1) is used which does not belong to the antenna field (AK) proper. The phases of the antennas (1 . . .