Abstract: A radar apparatus for estimating position of a plurality of obstacles. The radar apparatus includes a receive antenna unit. The receive antenna unit includes a linear array of antennas and an additional antenna at a predefined offset from at least one antenna in the linear array of antennas. The radar apparatus also includes a signal processing unit. The signal processing unit estimates an azimuth frequency associated with each obstacle of the plurality of obstacles from a signal received from the plurality of obstacles at the linear array of antennas. In addition, the signal processing unit estimates an azimuth angle and an elevation angle associated with each obstacle from the estimated azimuth frequency associated with each obstacle.

Abstract: A method is disclosed for suppressing sidelobes due to artifacts introduced by FFT operations during automotive radar signal processing. Sidelobes of a stronger target from the FFT operations may bury the response from a weaker target when there are multiple targets. The method estimates the sidelobes of an identified target from a measured FFT response and subtracts the estimated sidelobes from the measured FFT response. The identified target may be the strongest target from the measured FFT response. The method estimates the sidelobes to suppress the sidelobes with respect to the peak signal of the identified target. After the estimated sidelobes of the identified target are removed, the updated FFT response may reveal other targets that had been buried. The method may identify additional targets to estimate their sidelobes and may iteratively remove the estimated sidelobes of additional targets from the FFT until a desired sidelobe residual level is achieved.

Abstract: Various implementations of the invention compensate for “phase wandering” in tunable laser sources. Phase wandering may negatively impact a performance of a lidar system that employ such laser sources, typically by reducing a coherence length/range of the lidar system, an effective bandwidth of the lidar system, a sensitivity of the lidar system, etc. Some implementations of the invention compensate for phase wandering near the laser source and before the output of the laser is directed toward a target. Some implementations of the invention compensate for phase wandering in the target signal (i.e., the output of the laser that is incident on and reflected back from the target). Some implementations of the invention compensate for phase wandering at the laser source and in the target signal.

Abstract: A device, system, and method for volumetric ultrasound imaging is described. The device and system include an array of transducer elements grouped in triangular planar facets and substantially configured in the shape of a hemisphere to form a cup-shaped volumetric imaging region within the cavity of the hemisphere, A plurality of data-acquisition assemblies are connected to the transducers, which are configured to collect ultrasound signals received from the transducers and transmit image data to a network of processors that are configured to construct a volumetric image of an object within the imaging region based on the image data received from the data-acquisition assemblies.

Abstract: Embodiments of the present disclosure relate to cellular technology applications of beamforming performed in the digital domain. In one aspect, an RF system for performing digital beamforming on a per-carrier basis is disclosed, where different phase and/or amplitude adjustments are applied to signals of different frequency ranges (i.e., to different carrier signals). In another aspect, an RF system for performing digital beamforming on a per-antenna basis is disclosed, where different phase and/or amplitude adjustments are applied to signals transmitted from or received by different antennas. In some embodiments, an RF system may be configured to implement both digital beamforming on a per-carrier basis and digital beamforming on a per-antenna basis. The RF systems disclosed herein allow implementing programmable beamforming in the digital domain in a manner that is significantly less complex than conventional implementations.

Abstract: The present invention relates to a method and system of locating a wireless device using received signal strengths. The method comprising: determining a plurality of multiple sets of transmit beamforming weights corresponding to a plurality of access points (APs) associated with a plurality of time slots; transmitting a signal using said each of said plurality of multiple sets of transmit beamforming weights associated with said plurality of time slots by said each access point (AP) of said plurality of access points (APs); and generating a plurality of received signal strengths corresponding to said plurality of time slots associated with said each of said plurality of multiple sets of transmit beamforming weights by said each access point (AP) of said plurality of access points (APs) at any location.

Abstract: An embodiment of an antenna comprises an array of antenna elements arranged in groups of antenna elements adjustably coupled to respective reference waves. A multiplicity of patterns of antenna coupling settings are defined, each of which gives rise to a main lobe which points the antenna in a particular direction, each pattern also giving rise to respective side lobes. First and second such patterns may point the antenna in the same direction but with non-identical side lobes. In this way the clutter level from the side lobes relative to the main lobe is much smaller than would be the case if one of the patterns were employed both for transmitting and receiving. Alternatively, the first and second patterns may be used in quick succession both for transmitting, or used in quick succession both for receiving. The antenna may also switch rapidly between patterns where the main lobe points in a different direction in each pattern, allowing dithering of the beam or rapid switching between scanning and tracking.

Abstract: A plurality of software programmable processors is disclosed. The software programmable processors are controlled by rotating circular buffers. A first processor and a second processor within the plurality of software programmable processors are individually programmable. The first processor within the plurality of software programmable processors is coupled to neighbor processors within the plurality of software programmable processors. The first processor sends and receives data from the neighbor processors. The first processor and the second processor are configured to operate on a common instruction cycle. An output of the first processor from a first instruction cycle is an input to the second processor on a subsequent instruction cycle.

Abstract: Techniques are described herein for delivering retrodirective wireless radio frequency (RF) power to a client device in a wireless power delivery environment. More specifically, embodiments of the present disclosure describe techniques for delivering directed wireless RF power to a client device in a wireless power delivery environment via multiple wireless power signals over multiple wireless power delivery paths. The client device includes one or more RF client transceivers that collectively have a radiation and reception pattern in a three-dimensional space proximate to the client device. The techniques identify the wireless power delivery paths over which wireless power signals can be delivered and deliver the wireless power in a manner that matches the client radiation and reception pattern in the three-dimensional space proximate to the client device.

Abstract: A method comprising: performing one or more measurements in a user device to determine a plurality of beam groups, each beam group associating at least one receive beam direction of a user device and at least one transmit beam direction of an access point; and causing information on said beam groups to be transmitted to said access point.

Abstract: Provided are methods, systems, and apparatuses for recording a three-dimensional (3D) sound field using a vertically-oriented cylindrical array with multiple circular arrays at different heights. The design of the cylindrical array is well-suited to providing a high-resolution in azimuth and a reduced resolution in elevation, and offers improved performance over existing 3D sound reproduction systems. The methods, systems, and apparatuses provide a larger vertical aperture than horizontal aperture, as opposed to a spherical array, which has the same aperture for all dimensions, and further provides an alternative format to mixed-order spherical decomposition.

Abstract: An integrated circuit that includes different types of embedded functional blocks such as programmable logic blocks, memory blocks, and digital signal processing (DSP) blocks is provided. At least a first portion of the functional blocks on the integrated circuit may operate at a normal data rate using a core clock signal while a second portion of the functional blocks on the integrated circuit may operate at a 2× data rate that is double the normal data rate. To support this type of architecture, the integrated circuit may include clock generation circuitry that is capable of providing double pumped clock signals having clock pulses at rising and falling edges of the core clock signal, data concentration circuitry at the input of the 2× functional blocks, and data spreading circuitry at the output of the 2× functional blocks.

Abstract: Disclosed is a method of detecting an anomalous propagation condition in a Radar system, comprising the steps of: subtracting returns received in a first receive period from returns received in a succeeding second receive period, and repeating this step for a plurality of receive periods; and if the step of subtracting gives a result in excess of a predetermined threshold in one of the plurality of receive periods, then registering this as a possible anomalous propagation condition.

Abstract: Systems and methods for a diplexed antenna with semi-independent tilt are disclosed. The diplexed antenna supports two or more frequency bands, in which the vertical tilt of each of the supported frequency bands is separately controlled by a coarse level of phase shifting, but commonly controlled by a fine level of phase shifting.

Abstract: An apparatus and method for protecting a communication device of a railroad car is provided. The apparatus includes an antenna portion configured to include main antennas and an auxiliary antenna, a main receiver configured to check a magnitude of a received signal transferred through the main antennas of the antenna portion, an auxiliary receiver configured to check a magnitude of a received signal transferred through the auxiliary antenna of the antenna portion, and a controller configured to compare the magnitude of the signal received by the main receiver and the magnitude of the signal received by the auxiliary receiver, determine whether there is a jamming signal according to a comparison result, and take a preset countermeasure when it is determined that there is a jamming signal.

Abstract: The present disclosure provides a method for detecting a random access signal. The method includes: determining a temporary peak detection sequence according to a received time domain random access signal; determining an interference cancellation weight for a frequency domain cyclic shift sequence corresponding to a search window in the temporary peak detection sequence, and performing interference cancellation on the temporary peak detection sequence according to the interference cancellation weight, obtaining a final peak detection sequence; and performing peak detection on the final peak detection sequence. The present disclosure discloses an apparatus and system for detecting a random access signal at the same time. According to the method, the present disclosure can eliminate the deterioration of the leak detection performance and the false detection performance caused by the interference during the random access signal detection, improve the detection accuracy and save resources.

Abstract: Disclosed herein are a method of generating a correlation function with no side-peak and a system for tracking a BOC signal in order to synchronize the BOC signal. The method of generating a correlation function includes step S1 of generating sub-correlation functions {Sl(?)}l=0N?1, step S2 of generating a first final correlation function R0(?) by combining some of the sub-correlation functions, and step S3 of generating a second final correlation function Rproposed(?) by combining R0(?) with each of the remaining sub-correlation functions that have not been used for the combination at step S2. The BOC signal is one or more of BOCsin(kn,n) and BOCcos(kn,n) signals.

Abstract: An anti-jamming apparatus and method for a compact array antenna are provided. The anti-jamming apparatus for a compact array antenna includes a Global Navigation Satellite System (GNSS) array antenna unit including a plurality of GNSS antennas for receiving GNSS signals transmitted from a satellite. A first beam-forming unit includes a plurality of combination units for receiving respective signals received by the plurality of GNSS antennas as a first reference signal and first auxiliary signals and combining the first reference signal with the first auxiliary signals, thus forming different beams. A second beam-forming unit receives signals of the different beams, and combining the signals of the different beams, thus forming an anti-jamming beam in which an invisible area is minimized.

Abstract: An aircraft traffic system is provided that includes a primary antenna operable to generate interrogation signals and receive interrogation replies from other aircraft. The system additionally includes a secondary antenna configured as a tuned absorber having a matched impedance to at least partially absorb reflections of the interrogation signals or interrogation replies utilized by the primary antenna.

Abstract: A direction finding system for finding the angle of arrival of a target signal from a transmitter. The system includes a plurality of directional antennas positioned to face different directions for receiving the target signal. The antennas are mounted as an antenna array on a rotatable mount for supporting and rotating the antenna array. A receiver unit down converts the RF target signal to IF signals that are digitized by an A/D converter providing digital values. A computer computes the power in the signals from the A/D samples. A computer stores calibration information for the directional antennas, processes the digital values and the calibration information to determine a rotation angle ? for rotating the antennas to provide new digital values, processes the new digital values and the calibration information to determine an intersection angle, and subtracts the rotation angle from the intersection angle to determine the final value for the angle of arrival of the target signal.

Abstract: A communication system includes a first antenna, a second antenna, a first transceiver, a second transceiver, and a phase and power distribution transform circuit. The phase and power distribution transform circuit is coupled between the first antenna, the second antenna, the first transceiver, and the second transceiver. The phase and power distribution transform circuit is configured to adjust the phase and power of each signal from the first antenna, the second antenna, the first transceiver, and/or the second transceiver, thereby improving the communication quality of the communication system.

Abstract: Methods and apparatus for a phased array radar system including an array comprising columns of super-elements containing radiator elements located along a length of the super-element, wherein the super-elements form the columns such that super-elements are arranged end-to-end, wherein the super-elements are arranged in the column at randomized locations to reduce sidelobes. In a further embodiment, super element lengths can be randomized.

Abstract: Technologies are generally described for providing secured communications. In some examples, a method performed under control of a first device may include transmitting a jamming signal, receiving a mixed signal that includes the jamming signal and an information signal generated by a second device and obtaining the information signal by eliminating the jamming signal from the mixed signal.

Abstract: A system and method for selective suppression of sidelobe signals using controlled signal cancellation. An indication may be received from a single user equipment (UE) at each of two or more access points (APs) over the same channel. A relatively stronger power signal is received over a primary lobe of a communication beam of one of the APs and the relatively weaker power signal is received over a side lobe of a communication beam of another one of the APs. The efficacy of signal cancellation may be tested by turning signal cancellation on and off to measure the UE signals received at one of the APs. If interference is lower when signal cancellation is turned on, signal cancellation may be applied for continued communication with said UE to cancel side lobe signals and if interference is lower when signal cancellation is turned off, no signal cancellation may be applied.

Abstract: This disclosure provides a range side lobe removal device, which includes a pulse compressor for acquiring a reception signal from a radar antenna and generating a pulse-compressed signal by performing a pulse compression of the reception signal, a pseudorange side lobe generator for generating a pseudo signal of range side lobes of the pulse-compressed signal based on the reception signal, and a signal remover for removing a component corresponding to the pseudo signal from the pulse-compressed signal.

Abstract: Embodiments of the invention provide systems and methods for systems and methods for adaptively canceling interfering signals generated by a transmission antenna. Under one aspect, a system includes: an auxiliary antenna co-located with the main antenna, the auxiliary antenna configured to transmit an auxiliary signal to the victim antenna; a sensing antenna located on a line-of-sight path between the transmission antenna and the victim antenna, the sensing antenna configured to receive a composite of the interference and the auxiliary signal, and to output a first signal based on the received composite; a controller comprising an input coupled to the sensing antenna and configured to receive the first signal, the controller being configured to adjust at least one of an amplitude, a phase, a polarization, and a frequency characteristic of the auxiliary signal based on the first signal so as to reduce the composite of the interference and the auxiliary signal received by the sensing antenna.

Abstract: A method and apparatus for use in generating and imparting a low frequency, directed energy wavefield are disclosed. In a first aspect, the presently disclosed technique includes a low frequency directional array, comprising: a plurality of array elements capable of generating a low frequency, directed energy wavefront; and a canceling element capable of actively canceling a spurious lobe of the wavefront. In a second aspect, the presently disclosed technique includes a method, comprising: imparting a low frequency, directed wavefront; and actively canceling a spurious lobe of the wavefront.

Abstract: Described is a method of modifying an antenna pattern for a phased array antenna having at least one failed antenna element. A number of proximate beamformers in a proximate angular region about a beamformer at an angle of interest are determined. Each of the proximate beamformers has a proximate beamformer weight vector. A corrected beamformer weight vector is determined for the angle of interest as a linear combination of the proximate beamformer weight vectors. Each element of the corrected beamformer weight vector that corresponds to one of the failed antenna elements has a value of zero. The method enables computation of low spatial sidelobe antenna patterns without requiring a recalibration of the antenna thereby enabling uninterrupted operation of systems that employ phased array antennas. The method can also be used to control taper loss or sidelobe level for phased array antennas that have no failed antenna elements.

Abstract: A motion compensation method and system is included in a radar antenna system mounted on a moving platform which is subject to pitch, yaw and roll. The radar antenna system includes a main array antenna, and an auxiliary antenna. The auxiliary channel associated with the auxiliary antenna utilizes roll, pitch and yaw angle motion compensations as its auxiliary antenna always steers a horizontal fan shape beam at the horizon to blank any surface (land or sea) based EM interferences. Such motion compensations are provided by a ship motion compensator component and process included within the antenna system. The ship motion compensator component in response to platform motion signals indicative of changes in platform motion angles generates new sets of values using an initial set of weighting coefficient values as a function of such angle motion changes.

Abstract: A technique for determining the angles of arrival of signals incident on an antenna array from directions within an angular region of interest involves supplying outputs of antenna elements of the antenna array to a number of different weight generators. Each of the weight generators produces a set of beam-forming weights that maximizes a signal-to-interference ratio of a locally generated signal corresponding to a look angle that is outside the region of interest, with signals at different look angles being supplied to the different weight generators. An annihilation operator is determined from the sets of beam-forming weights generated by the weight generators and from beam-forming vectors representing the look angles of the locally generated signals used in the weight generators. The annihilation operator is applied to a group of beam-forming vectors representing angles within the region of interest to determine angles of arrival of signals within the region of interest.

Abstract: Embodiments of the invention provide systems and methods for systems and methods for adaptively canceling interfering signals generated by a transmission antenna. Under one aspect, a system includes: an auxiliary antenna co-located with the main antenna, the auxiliary antenna configured to transmit an auxiliary signal to the victim antenna; a sensing antenna located on a line-of-sight path between the transmission antenna and the victim antenna, the sensing antenna configured to receive a composite of the interference and the auxiliary signal, and to output a first signal based on the received composite; a controller comprising an input coupled to the sensing antenna and configured to receive the first signal, the controller being configured to adjust at least one of an amplitude, a phase, a polarization, and a frequency characteristic of the auxiliary signal based on the first signal so as to reduce the composite of the interference and the auxiliary signal received by the sensing antenna.

Abstract: A method of for processing signals in a radar system is shown comprising an antenna system having at least two antenna elements, a beam forming arrangement (ABF_RX, ABF_TX) for selectively steering the directivity of the antenna system in a given selected direction, the directivity of the antenna system having a main lobe in the selected direction and a back lobe (BL) in another direction and of a lower magnitude than the main lobe. By utilizing various scale and subtract processing both noise levels and ghost signals can be considerably reduced. A SAR radar apparatus has moreover been shown.

Abstract: The Energy spectral density of OFDM signals inherently rolls off slowly. Slow OFDM spectral rolloff has system level implications traditionally mitigated by some combination of the following: addition of bandlimiting filtering; use of significant guard bands of zeroed tones; and, guard time shaping. Each of these techniques negatively impact system performance and/or flexibility. This application presents a methodology for active cancellation of out of band spectral energy. The technique can be used by itself or in conjunction with above traditional methods to help control out of band emission. Examples of the use of the new technique are provided. Computational cost of the new technique is also discussed.

Abstract: The invention relates to a learning process for an ultra wideband communication system with M transmission antennas and N reception antennas and in which the information is modulated on L possible positions comprising the following steps: a) transmit a series of Nseq learning pulses from each emission antenna to all reception antennas. b) for each reception antenna j, estimate the M composite responses of series of emitted pulses that arrive at this reception antenna j, each composite response being estimated by eliminating the effects of other antennas. c) estimate correlations between the different channels.

Abstract: According to a particular embodiment, a method for evaluating different antenna designs includes receiving different sets of antenna patterns representative of the different antenna designs from a corresponding number of data sources. The different sets of antenna patterns are applied to a characterizer component for generating a sidelobe banking (SLB) characteristic map for each set of antenna patterns received. A SLB effectiveness chart is generated from the SLB characteristic map. A best antenna weighting set is selected based on which auxiliary antenna pattern exhibits the best performance. The best of antenna weighting factors are used for designating the antenna design having superior SLB performance characteristics.

Abstract: A wide-angle null-fill antenna with no null in the depression angle range, an omni antenna using the same, and radio communication equipment. A null-fill antenna comprises a first antenna array including antenna elements arranged with a prescribed point as the center, and a second antenna array having amplitude characteristics substantially equal to those of the antenna elements forming the first antenna array. The first antenna array is excited so that the excitation amplitude distribution is to have symmetry with respect to the prescribed point, while the excitation phase distribution is to have point symmetry with respect to the prescribed point. The phase center of the first antenna array is substantially coincident with that of the second antenna array.

Abstract: Embodiments include a method to suppress side lobes of a main antenna by creating cancellation directions using a Side Lobe Canceller (SLC). Various embodiments also provide the Side Lobe Canceller.

Abstract: The present invention relates to the field of protecting geographic areas against undesirable, even hostile, intrusions from threatening moving objects. The subject of the invention is a bistatic radiofrequency detection barrier having means for transmitting one or more waves through a directional antenna and means for receiving signals through a directional antenna pointing in the transmission direction. This antenna includes auxiliary means for transmitting a wave through a non-directional antenna and means for comparing the relative levels of the echos received from the wave transmitted by the main, directional transmission channel, and the echos originating from the wave transmitted by the auxiliary transmission channel. The result of the comparison makes it possible to identify the echos deriving from a wave transmitted in the direction of the side lobes of the directional transmission antenna, and so reduce the number of false intrusion alarms.

Abstract: The method and system of the present invention includes a SLB characterizer component for achieving optimum sidelobe blanking through the combining of multiple dimension data into a single figure of merit comparison. The SLB characterizer component is positioned between a radar data processor and beam steering generator of a radar system. The radar data processor provides several sets of antenna patterns which are used by the characterizer component to compute gain margins according to the teachings of the present invention. From the computed gain margins, the component generates SLB characteristic maps which provide a much less complex method for evaluating antenna design independent of other system parameters. Based on such SLB characteristic maps, the characterizer component generates SLB effectiveness charts which it uses to compare SLB performance and determine which auxiliary antenna pattern has the best performance.

Abstract: Very efficient sidelobe suppression of Barker codes is achieved through the use of a mismatched filter, which is comprised of a conventional matched filter cascaded with a computationally efficient filter based on multiplicative expansion. Several constant parameters are introduced in the terms of the expansion and are optimized to improve the performance of the filter. Optimized mismatched filters for length 13, 11, 7 and 5 Barker codes are presented. For each of these codes, filters with one, two and three stages are studied. The technique is extended to compound Barker codes based on their representation in a factored form in the z-domain. Hardware requirements for the filters discussed in the disclosure are also presented.

Abstract: A radar device uses a transmission signal outputted from a transmission antenna and a reception signal as an incoming wave reflected from a target object through an arrangement of reception antennas for estimating an angle of the incoming wave. An incoming wave estimation process stores a threshold for each beat frequency of the beat signal, and distinguishes the incoming wave in a signal space from the incoming wave in a non-signal space using the threshold. The estimation process facilitates an accurate estimation of the incoming wave in MUSIC method, ESPRIT method or the like.

Abstract: Coverage areas for wireless networks are divided into a plurality of cells that are arranged in rows. Channel frequencies are assigned to cell sectors and associated with respective antenna axes. The antenna axes of adjacent rows are alternatingly rotated, thereby reducing co-channel interference. In an example, an available bandwidth is divided into twelve channel frequencies, so that a cell cluster includes four cells. Co-channel cells associated with half the channel frequencies are assigned to cells in the first row of cells, and the remainder are assigned to cells in the second row.

Abstract: A method for generating a multiresolution decomposition of an array signal by a bank of spatial bandpass filters is disclosed. The signal processing operation is implemented through the use of the directivities of the individual array elements and does not degrade the spatial or temporal resolution of the array.

Abstract: An adaptive algebraic interference cancellation technique for canceling interference from a signal of interest received by an array of antenna elements involves: generating a set of antenna element signals that reflect reception of the signal of interest and interference at the respective antenna elements; adaptively determining the direction of one or more interference sources received with the signal of interest; for each interference source, constructing a directional interference vector corresponding to the direction of the interference source; computing a projection operator that transforms each directional interference vector to a zero vector; applying the projection operator to the antenna element signals to remove interference from the antenna element signals; and restoring the signal of interest by individually compensating the antenna element signals for distortion to the signal of interest cause by applying the projection operator.

Abstract: Novel methods and structures are disclosed herein which employ pseudorandom sequences to spatially arrange multiple sources in a pseudorandom source array. The pseudorandom source array can replace the single source in analytical instruments relying on spatial separation of the sample or the probe particles/waves emitted by the sources. The large number of sources in this pseudorandom source array enhances the signal on a position sensitive detector. A mathematical deconvolution process retrieves a spectrum with improved signal-to-noise ratio from the detector signal.

Abstract: An antenna system has multiple antenna feed elements combined in a number of element sets independently controlled to provide a beam of a variable size. Multiple input power dividers are provided for dividing an input signal, and multiple phase controllers are respectively connected to outputs of the power dividers for producing a plurality of phase-shifted signals having prescribed phases. The phase-shifted signals are supplied to respective inputs of a hybrid matrix. Predetermined outputs of the hybrid matrix are connected to summation circuitry for providing in-phase power summation of signals produced at these outputs. The antenna elements in at least one of the element sets are controlled by a sum signal produced by the summation circuitry. The other element sets may be controlled by respective output signals of the hybrid matrix.

Abstract: Various techniques are disclosed to suppress undesired signal components introduced by non-linear amplifiers of phased array antenna systems to accommodate bandwidths greater than one octave. For example, in accordance with one embodiment, a phased array antenna system includes first and second antenna elements adapted to provide first and second received signals in response to a radio signal. The second antenna element is rotated approximately 180 degrees in relation to the first antenna element. Amplifiers may amplify the received signals to provide amplified signals having a bandwidth greater than one octave. Undesired components of the amplified signals introduced by the amplifiers may be suppressed through appropriate phase shifts performed by associated phase shifters and/or power combiners.

Abstract: An embodiment of an electronically scanned array antenna includes an array of radiative elements having an array height. A plurality of separate subarrays of the radiative elements include a first row comprising a first plurality of subarrays, wherein subarrays of the first plurality of subarrays are horizontally non-overlapping with one another, and a second row comprising a second plurality of subarrays. The subarrays of the second row are arranged vertically adjacent to the subarrays of the first row, wherein subarrays of the second plurality of subarrays are horizontally non-overlapping with one another. The radiative elements of the separate subarrays are not shared with any other subarray. The subarrays of the radiative elements have subarray heights which are smaller than the array height.

Abstract: An apparatus for simultaneously receiving a first signal from a non-terrestrial source and a second signal from a terrestrial source on the same or overlapping channels using a receive antenna with posteriorly-directed sidelobes is disclosed. The apparatus comprises at least one terrestrial transmitter transmitting information on at least one frequency simultaneously usable by at least one satellite transmitting to a satellite receive antenna having a sensitivity characterizable by a primary sensitive axis directed substantially at satellite. The terrestrial transmitter includes a azimuthal gain characteristic directed substantially away from the Earth's Equator. In an alternative embodiment, the terrestrial transmitter is disposed at a location defining a vector angularly displaced from the primary sensitive axis by an angle of less than 90 degrees. A method of transmitting information is also disclosed.

Abstract: A positioning system receiver is disclosed. The positioning system receiver includes an antenna for receiving radio frequency (RF) signals. The positioning system receiver also includes a radio frequency front end system configured to convert the received RF signals into intermediate frequency signals. The positioning system receiver further includes a digital processing and correlation system, receiving the intermediate frequency signals and including a plurality of taps on the autocorrelation function main lobe and a plurality of taps on at least one of the autocorrelation function side lobes. The digital processing and correlation system uses the signals received from the taps in a dot product detector algorithm to improve the signal-to-noise ratio of the receiver system.