Abstract: Effective radio frequency interference (RFI) mitigation techniques are disclosed for use in wireless communication devices, among others. An RFI mitigation circuit may include a selector circuit to select between a cleaned signal and a clipped signal, and provide the selected signal as an output signal. The RFI mitigation circuit may also include a classifier circuit to generate a control input indication to the selector circuit to have the cleaned signal selected as the output signal based at least on a front-end circuit signal indicating that the front-end circuit is operating linearly and also indicating that the front-end circuit signal includes an interference signal. The classifier circuit may also generate the control input indication to have the clipped signal selected as the output signal based at least on the front-end circuit signal indicating that the front-end circuit is not operating linearly.

Abstract: A signal processing device includes a prediction and correction engine configured to receive a signal including a target signal, and to execute a single-moment filter, based on a current measurement sample of the signal and a model of the target signal, to obtain a single-moment state estimate and a single-moment state estimate error covariance for the target signal, a covariance renormalizer configured to determine a multi-moment state estimate error covariance for the target signal based on a prior single-moment state estimate error covariance, corresponding to a sample prior to the current measurement sample, and the single-moment state estimate error covariance, and a multi-moment prediction and correction engine configured to execute a multi-moment filtering extension based on the current measurement sample and the multi-moment state estimate error covariance to obtain a multi-moment state estimate, and further configured to determine an estimate for the target signal based on the multi-moment state esti

Abstract: A signal processing device includes a prediction and correction engine configured to receive a signal including a target signal, and to execute a single-moment filter, based on a current measurement sample of the signal and a model of the target signal, to obtain a single-moment state estimate and a single-moment state estimate error covariance for the target signal, a covariance renormalizer configured to determine a multi-moment state estimate error covariance for the target signal based on a prior single-moment state estimate error covariance, corresponding to a sample prior to the current measurement sample, and the single-moment state estimate error covariance, and a multi-moment prediction and correction engine configured to execute a multi-moment filtering extension based on the current measurement sample and the multi-moment state estimate error covariance to obtain a multi-moment state estimate, and further configured to determine an estimate for the target signal based on the multi-moment state esti

Abstract: The invention described herein presents a system and method to overcome the distortions and affectations introduced by the highly variant channels of one or several antennas both in the transmitter and in the receiver. Unlike any existing invention that operates under the same conditions, this device uses a completely new reception technique based on the concept of virtual trajectories in which iterative calculations or solution of linear systems in operating time are not required, thus saving a considerable amount of operations. The receiver of this device manages to convert the fast variations of the channel into virtual antennas, thus achieving a considerable increase in the signal to noise-interference ratio. The resulting performance in terms of noise immunity is much better than any technique found so far and also requires a much smaller amount of calculations in the receiver.

Abstract: A modified orthogonal frequency-division multiplexing (OFDM) communication system based on virtual decomposition of the channel is proposed. The system is fully compatible with standard OFDM transmitters and maintains several blocks of standard OFDM receivers. The proposed approach achieves also incoherent reception of multicarrier signals even with a simple autocovariance DPSK detector. This novel system substantially surpasses the performance of current approaches while requiring low computational complexity. Two preferred embodiments are described; one with coherent reception using pilot signals, and the second with incoherent receiver of differentially encoded signals.

Abstract: A modified orthogonal frequency-division multiplexing (OFDM) communication system based on virtual decomposition of the channel is proposed. The system is fully compatible with standard OFDM transmitters and maintains several blocks of standard OFDM receivers. The proposed approach achieves also incoherent reception of multicarrier signals even with a simple autocovariance DPSK detector. This novel system substantially surpasses the performance of current approaches while requiring low computational complexity. Two preferred embodiments are described; one with coherent reception using pilot signals, and the second with incoherent receiver of differentially encoded signals.

Abstract: Described are methods and systems for mitigating radio-frequency interference (RFI) generated by a receiving platform. After downconverting a received RF signal to baseband, the RFI component in the baseband signal may be estimated using a model-based estimator (e.g., a nonlinear filter such as an extended Kalman filter) that is tuned to a statistical model of the RFI source. The estimated RFI component may then be subtracted from the baseband signal to yield a compensated baseband signal from which may be extracted the baseband information signal. This filtering technique enables a highly accurate mitigation of the RFI even when the RFI power is much smaller compared to the Gaussian channel noise.