56results about "Direction-finding diversity systems using radio waves" patented technology

A method and apparatus for determining the range, radial velocity, and bearing angles of scattering objects reflecting RF signals or for determining the range, radial velocity, and bearing angles of sources RF signals. An array of antenna elements is utilized, the array of antenna elements each having an associated two state modulator wherein transmitted and/or received energy is phase encoded according to a sequence of multibit codes, the bits of the multibit codes each preferably having two states with approximately a 50% probability for each of the two states occurring within each given multibit code in said sequence of multibit codes, thereby allowing the determination of range, radial velocity, and bearing angles through digital computation after the scattered signals have been received.

The present invention relates to methods and apparatus for tracking moving objects, such as ballistic missiles and aircraft, on the basis of discrete sensor measurements, such as radar reports and reports from optical sensors. In particular, but not exclusively, the invention is useful for the simultaneous tracking of multiple, fast moving, closely spaced objects, such as deploying ballistic missiles and raids of fast agile aircraft, in which the track dynamics of each object are modelled using a collection of autonomous, i.e. non-interacting, multiple dynamics models. Embodiments of the invention were particularly developed to be effective in tracking ballistic missiles using early warning radar, and similarly demanding and complex battle scenarios.

The present invention relates to an apparatus for estimating an arrival-angle of a reception signal and a beam-forming apparatus in a radio wave receiver, such as radar. More specifically, the present invention relates to an apparatus for accurately estimating an arrival-angle of a reception signal, or an apparatus for performing the beam-forming of a reception signal by using a multi-reception array antenna, by using a reference value that is obtained by calculating the degree of distortion of the magnitude and phase of a signal for each reception angle.

A radio communication apparatus includes a variable directivity antenna and a control unit and performs radio communication with another radio communication apparatus. The control unit calculates a position of the another radio communication apparatus by measuring a distance to the another radio communication apparatus and measuring directivity of the another radio communication apparatus by switching directivity of the wave of radio communication using the variable directivity antenna with a MEMS switch. Moreover, the control unit controls the output of the variable directivity antenna according to the calculated position of the another radio communication apparatus.

An Advanced Focal Plane Array (“AFPA”) for parabolic dish antennas that exploits spatial diversity to achieve better channel equalization performance in the presence of multipath (better than temporal equalization alone), and which is capable of receiving from two or more sources within a field-of-view in the presence of multipath. The AFPA uses a focal plane array of receiving elements plus a spatio-temporal filter that keeps information on the adaptive FIR filter weights, relative amplitudes and phases of the incoming signals, and which employs an Interference Cancelling Constant Modulus Algorithm (IC-CMA) that resolves multiple telemetry streams simultaneously from the respective aero-nautical platforms. This data is sent to an angle estimator to calculate the target's angular position, and then on to Kalman filters FOR smoothing and time series prediction. The resulting velocity and acceleration estimates from the time series data are sent to an antenna control unit (ACU) to be used for pointing control.

Iterative methods for direction of arrival estimation of a signal at a receiver with a plurality of spatially separated sensor elements are described. A quantized estimate of the angle of arrival is obtained from a compressive sensing solution of a set of equations. The estimate is refined in a subsequent iteration by a computed error based a quantized estimate of the direction of arrival in relation to quantization points offset from the quantization points for the first quantized estimate of the angle of arrival. The iterations converge on an estimated direction of arrival.

This patent concerns a compact and portable system for real-time detection and location of electromagnetic emissions in the spectrum used by mobile devices (cell phones and Wi-Fi/Bluetooth devices). The principle of detection and location is based on phased array technology, which enables the synthesis of a directional radiation beam that can be electrically controlled in terms of both its shape and direction. This technology is used primarily in military and astronomical applications. The device also includes localization and control algorithms. This device will allow for detecting and locating electromagnetic emissions by means of an antenna beam scan within a field of view of 80×80 degrees. Once the detection and location have been established, the results are overlaid to a visual image captured by a video camera.

The invention provides a high-precision positioning algorithm and device for a bistatic EMVS-MIMO radar, and the algorithm comprises the steps: constructing a sample matrix after the matched filteringof a receiving array, and calculating a covariance matrix estimation value of a received signal; constructing a high-order received signal covariance tensor model by using the Tucker tensor model; performing high-order singular value decomposition on the high-order covariance tensor model to obtain a new signal subspace and a new noise subspace; obtaining estimation of an azimuth angle and a pitch angle of the target and estimation of a two-dimensional polarization angle by using a rotation invariant technology and a vector cross product technology; and pairing of DODs and DOAs is realized byusing a subspace orthogonal principle. According to the method, a tensor structure for receiving array signals is considered, and high-precision target multi-parameter estimation can be obtained based on a tensor subspace algorithm.