Abstract: Physical layer processing methods for network acquisition by remote nodes in wireless communication systems are described herein. New methods for wireless network discovery and synchronization by remote nodes are described herein that utilize spatial (e.g., antenna array) processing algorithms which may achieve enhanced functioning in challenging radio frequency environments, such as those containing interference and multipath distortion effects. These methods may include advantageous use of spatial whiteners and associated pluralities of adaptive beamformers to detect network reference and synchronization signals and estimate their parameters.

Abstract: Examples described herein include sliding window methods for calculating frequency-localized weights for adaptive beamformers. A window of subcarriers may be used to calculate a cross-correlation vector, inverse covariance matrix, or other components used in a weight calculation for a particular subcarrier. In some examples, a next window of subcarriers may include additional subcarriers, and may not include other subcarriers. The previously-calculated cross-correlation vector, inverse covariance matrix, or other components may be updated in accordance with updates and downdates associated with the added and removed subcarriers. The updated components may be used to generate weights for a subcarrier in the next window.

Abstract: Systems and methods are described for performing interference-resistant calibration and compensation of radio-frequency (RF) and analog front-end electronics of antenna-array based receivers during active operation. Examples of systems and methods are described herein that may provide interference-resistant calibration maintenance and ongoing compensation for changing gain and phase in receiver front-end electronic components, due to manufacturing tolerances and operational and environmental factors such as variations in temperature, humidity, supply voltage, component aging, connector oxidation, mechanical stresses and vibration, and/or maintenance operations such as sparing and swapping of cables, front-end electronics modules, and/or associated circuitry.

Abstract: Physical layer processing methods for network acquisition by remote nodes in wireless communication systems are described herein. New methods for wireless network discovery and synchronization by remote nodes are described herein that utilize spatial (e.g., antenna array) processing algorithms which may achieve enhanced functioning in challenging radio frequency environments, such as those containing interference and multipath distortion effects. These methods may include advantageous use of spatial whiteners and associated pluralities of adaptive beamformers to detect network reference and synchronization signals and estimate their parameters.

Abstract: Examples described herein include recursive techniques for calculating frequency-localized weights for adaptive beamformers. Components of solutions for other subcarriers are weighted and used to calculate weights for a particular subcarrier. For example, a previously-calculated cross-correlation vector and/or inverse covariance matrix from another subcarrier may be updated for use in calculating weights for a subsequent subcarrier. In some examples, the previously-calculated components are weighted by a forgetting factor. The previously-calculated components themselves may have weighted contributions from yet previously-calculated components.

Abstract: Physical layer processing methods for network acquisition by remote nodes in wireless communication systems are described herein. New methods for wireless network discovery and synchronization by remote nodes are described herein that utilize spatial (e.g., antenna array) processing algorithms which may achieve enhanced functioning in challenging radio frequency environments, such as those containing interference and multipath distortion effects. These methods may include advantageous use of spatial whiteners and associated pluralities of adaptive beamformers to detect network reference and synchronization signals and estimate their parameters.

Abstract: Examples described herein include Weighted Overlap Beamform and Add techniques for calculating frequency-localized weights for adaptive beamformers. Intermediate weights are calculated for overlapping subbands (e.g., using a least-squares solution or a windowed least-squares solution). Each set of intermediate weights may be multiplied by an overlap factor, and combined to provide final weights for a subcarrier.

Abstract: Examples described herein include sliding window methods for calculating frequency-localized weights for adaptive beamformers. A window of subcarriers may be used to calculate a cross-correlation vector, inverse covariance matrix, or other components used in a weight calculation for a particular subcarrier. In some examples, a next window of subcarriers may include additional subcarriers, and may not include other subcarriers. The previously-calculated cross-correlation vector, inverse covariance matrix, or other components may be updated in accordance with updates and downdates associated with the added and removed subcarriers. The updated components may be used to generate weights for a subcarrier in the next window.

Abstract: Systems and methods are described for performing interference-resistant calibration and compensation of radio-frequency (RF) and analog front-end electronics of antenna-array based receivers during active operation. Examples of systems and methods are described herein that may provide interference-resistant calibration maintenance and ongoing compensation for changing gain and phase in receiver front-end electronic components, due to manufacturing tolerances and operational and environmental factors such as variations in temperature, humidity, supply voltage, component aging, connector oxidation, mechanical stresses and vibration, and/or maintenance operations such as sparing and swapping of cables, front-end electronics modules, and/or associated circuitry.

Abstract: Examples described herein include Weighted Overlap Beamform and Add techniques for calculating frequency-localized weights for adaptive beamformers. Intermediate weights are calculated for overlapping subbands (e.g., using a least-squares solution or a windowed least-squares solution). Each set of intermediate weights may be multiplied by an overlap factor, and combined to provide final weights for a subcarrier.

Abstract: Physical layer processing methods for network acquisition by remote nodes in wireless communication systems are described herein. New methods for wireless network discovery and synchronization by remote nodes are described herein that utilize spatial (e.g., antenna array) processing algorithms which may achieve enhanced functioning in challenging radio frequency environments, such as those containing interference and multi path distortion effects. These methods may include advantageous use of spatial whiteners and associated pluralities of adaptive beamformers to detect network reference and synchronization signals and estimate their parameters.

Abstract: A method and system is provided for detecting and characterizing pulsed threat radar emitters through heavy in-band interference. System includes an advanced digital signal processing method provides spatial and temporal interference cancellation, super-resolution direction-finding, and high resolution spectrum analysis techniques. The system receives the digitized output of a discriminator bank and produces highly accurate threat pulse radio frequency estimates. The invention further provides a two-channel configuration for a DF subsystem, to perform adjacent-beam direction-finding through severe interference environments. The invention provides increased sensitivity, increased frequency accuracy, and up to 40 dB of increased interference look-through capability in ES system but remains transparent to ES system functioning and to ES system operators.

Abstract: A method and system is provided for detecting and characterizing pulsed threat radar emitters through heavy in-band interference. System includes an advanced digital signal processing method provides spatial and temporal interference cancellation, super-resolution direction-finding, and high resolution spectrum analysis techniques. The system receives the digitized output of a discriminator bank and produces highly accurate threat pulse radio frequency estimates. The invention further provides a two-channel configuration for a DF subsystem, to perform adjacent-beam direction-finding through severe interference environments. The invention provides increased sensitivity, increased frequency accuracy, and up to 40 dB of increased interference look-through capability in ES system but remains transparent to ES system functioning and to ES system operators.