Abstract: The system and method prevents reception of calls to a mobile cellular device within a relatively small area or zone, with minimal inconvenience to the public by also permitting outgoing transmissions. The mobile cellular device has a wirelessly settable parameter associated therewith enabling establishment of an inbound call. A selective call blocker includes a receiver, a transmitter, and a selective call blocking controller cooperating with the receiver to determine the wirelessly settable parameter. The selective call blocking controller also cooperates with the transmitter to wirelessly change the wirelessly settable parameter to selectively block an inbound call to the mobile cellular device and without defeating the capability of the mobile cellular device to establish an outbound call.

Abstract: A communications device includes a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors. A Kalman filter receives the communications signal from the time/frequency error measurement circuit and processes the signal using a multi-level state error covariance matrix P for controlling the Kalman gain in the Kalman filter. An on-line monitoring circuit is operative with the Kalman filter for monitoring the actual state errors in time and frequency and controlling the state error covariance matrix P based on a measured error threshold.

Abstract: A digital signal processing-based receiver architecture performs automatic gain control (AGC) for a frequency hopping spread-spectrum communications receiver that may be subjected to one or more sources of interference or jamming. Rather than set the AGC gain at a fixed, best hoped for value, and then attempt to rely on decoding or interleaving to interpolate lost or degraded data, the present invention, through repeated but aperiodic transitions or hops across a plurality of frequency bins of interest, develops a gain profile for the plurality of frequency bins, and uses the gain profile to adjust, on a hop-by-hop basis, the gain for the channel/bin to which the receiver is listening, so as to maintain the average aggregate input signal power at an optimal ADC loading factor.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.

Abstract: A frequency mixer includes a semiconductor substrate. An input current feedback amplifier is formed on the semiconductor substrate and receives a radio frequency (RF) signal and a local oscillator (LO) signal. An inverting current feedback amplifier is formed on the semiconductor substrate and connected to the input current feedback amplifier for inverting the LO signal and producing a half-wave signal. An output current feedback amplifier is formed on the semiconductor substrate and connected to an output of the input and inverting current feedback amplifiers and operative as an inverting summer for the RF and LO signals such that the output polarity of the RF signal is reversed.

Abstract: A communications device includes a time/frequency error measurement circuit that receives a communications signal and measures its timing and frequency errors. A Kalman filter receives the communications signal from the time/frequency error measurement circuit and processes the signal using a multi-level state error covariance matrix P for controlling the Kalman gain in the Kalman filter. An on-line monitoring circuit is operative with the Kalman filter for monitoring the actual state errors in time and frequency and controlling the state error covariance matrix P based on a measured error threshold.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.

Abstract: A receiver includes a matched filter matched to a synch pulse and generates a matched filter output signal having peaks and valleys with one of the peaks corresponding to the synch pulse. An orthogonal filter is inversely matched to the synch pulse and generates an orthogonal filter output signal having peaks and valleys with one of the valleys corresponding to the synch pulse. A detector determines the synch pulse based upon a largest difference between the matched filter output signal and the orthogonal filter output signal.

Abstract: A frequency mixer includes a semiconductor substrate. An input current feedback amplifier is formed on the semiconductor substrate and receives a radio frequency (RF) signal and a local oscillator (LO) signal. An inverting current feedback amplifier is formed on the semiconductor substrate and connected to the input current feedback amplifier for inverting the LO signal and producing a half-wave signal. An output current feedback amplifier is formed on the semiconductor substrate and connected to an output of the input and inverting current feedback amplifiers and operative as an inverting summer for the RF and LO signals such that the output polarity of the RF signal is reversed.

Abstract: An apparatus and method for transmitting and receiving a communication signal includes selecting a pulse shape for a continuous phase modulated waveform, encoding specific information into the waveform to form a communication signal and transmitting the communication signal. The system receives the transmitted communication signal and samples the received signal at a specified rate, the sample rate being less than the symbol rate, enabling reconstructing the waveform and extracting encoded information at sub sample per symbol rates, thereby reducing the reliance on high speed wideband analog to digital converters (ADC) for high speed applications.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.

Abstract: A data management architecture for a high speed packet switch has a dual key-based content addressable memory (CAM)-based buffer access control mechanism that stores relatively long data packets for delivery to multiple output ports of the switch. The CAM stores multiple address pointer words, each having a key field to identify a data packet, and an address field to identify the address of the location of the packet buffer in which the data packet is stored. During a CAM search, a packet request key is coupled to the key fields of all address pointer words stored in the CAM. The location of the matching key is used to access the key field's companion address field in its address pointer word to access a data packet stored in the packet buffer, and to address fields of all address pointer words stored in the CAM. The CAM outputs a signal that indicates whether or not the buffer address from which the packet has been accessed is free to store new data.

Abstract: A signal to noise ratio estimator and method for a received signal which includes a communication component and a noise component is disclosed. One embodiment is an in-service, blind, decision-directed estimator for a CPFSK communication signal. A preferred embodiment determines the power of a communication signal component by combining the received signal with a signal that is a delayed complex conjugate of the received signal and then removing the real component of the combined signal.

Abstract: Embodiments of a system and method are disclosed that exploit the unique higher order statistics of temporally dependent waveforms to detect and enumerate signals in a multi-signal and noise environment. The embodiments use spatial 4th-order cumulants or spatial 2nd-order moments in a Blind Source Separation operation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues for a set of unknown signals. Sequential detection in the complex plane of the eigenvalues in associated tracks for successive blocks of sensor data serve as the basis of the detection decision. The embodiments may include a multi-element array and do not require a priori knowledge of the signal environment to detect and enumerate the signals.

Abstract: A receiver exploits unique higher order statistics of temporally dependent waveforms to classify, characterize, identify (fingerprint) and intercept a waveform within the field of view of the receiver. The method uses 4th-order non zero lag auto cumulants of the received waveform and 4th-order non zero lag auto cumulants of known waveforms to classify and characterize the signal. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source obtain a fingerprint.

Abstract: A synthetic aperture radar (SAR) compensates for ionospheric distortions based upon measurement of the group delay, particularly when operating in the VHF/UHF band. The SAR is based upon a multi-input multi-output (MIMO) technique for estimating the effective ionospheric conditions, which is referred to as the group delay approach. The group delay approach is divided into a 1-dimensional (range) approach and a 2-dimensional (range and cross-range) approach. The group delay measures the effective or observed TEC, which is used to reduce the ionospheric distortion.

Abstract: A synthetic aperture radar (SAR) for a moveable platform includes an antenna, a radar transmitter and radar receiver cooperating with the antenna. A radar processor is connected to the radar transmitter and radar receiver to account for the Faraday rotation introduced by propagation through the ionosphere by estimating an individual ionospheric distortion for each received echo pulse based upon a measured Faraday rotation, and reducing the ionospheric distortion for each received echo pulse based upon the estimated individual ionospheric distortion associated therewith for providing a compensated echo pulse.

Abstract: Embodiments of a system and method are disclosed that exploit the unique higher order statistics of temporally dependent waveforms to detect and enumerate signals in a multi-signal and noise environment. The embodiments use spatial 4th-order cumulants or spatial 2nd-order moments in a Blind Source Separation operation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues for a set of unknown signals. Sequential detection in the complex plane of the eigenvalues in associated tracks for successive blocks of sensor data serve as the basis of the detection decision. The embodiments may include a multi-element array and do not require a priori knowledge of the signal environment to detect and enumerate the signals.

Abstract: A receiver exploits unique higher order statistics of temporally dependent waveforms to classify, characterize, identify (fingerprint) and intercept a waveform within the field of view of the receiver. The method uses 4th-order non zero lag auto cumulants of the received waveform and 4th-order non zero lag auto cumulants of known waveforms to classify and characterize the signal. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source obtain a fingerprint.

Abstract: A transmitted signal's higher order statistics of temporally dependent waveforms are exploited to geolocate low power signals. The geolocation is independent of the characteristics or encoded data of the transmitted waveform. The method uses spatial fourth order cumulants or spatial second order moments in a Blind Source Separation and generalized eigenvalue decomposition to determine unique matrix pencil eigenvalues and eigenvectors. The eigenvectors provide are orthogonal to the steering vector of the transmitted signal save one, which represents the steering vector. This property is used to determine Steering vectors, AoA or geolocation. The receiver includes a multi-element array and does not need a priori knowledge of the transmitted signal source to geolocate the target transmitter. The methods and apparatus for geolocation does not require typical demodulation.