Techniques described herein provide cancelation of cross-polarization interference during simultaneous receipt of radiofrequency signals (e.g., an X-signal and a Y-signal) in a same frequency channel in nominally orthogonal polarizations. Though nominally orthogonally polarized, each signal contributes some cross-polarization interference to the other. Embodiments receive and demodulate each signal by a corresponding demodulator to generate corresponding X-symbol and Y-symbol decision signals, referenced to a common clock domain. An X-channel adaptive canceler (X-CAC) generates an X-output signal by using one or more Y-symbol decision signals adaptively to cancel cross-polarization interference from the Y-signal, and a Y-CAC generates a Y-output signal by using one or more X-symbol decision signals adaptively to cancel cross-polarization interference from the X-signal (e.g., the X-CAC and the Y-CAC each using a first-order least mean squares control loop). The resulting X-output signal and Y-output signal can be further decoded and output by the receiver to downstream systems and/or components.

An adaptive filter includes a frequency domain adaptation block that analyzes a statistic of coefficient movement in the frequency domain. The adaption block adjusts, in the frequency domain, a parameter (step size or leakage factor) that affects speed of convergence of the adaptive filter based on the analyzed statistic of filter coefficient movement. The filter includes an associated coefficient, statistic of coefficient movement, and parameter for each frequency bin. The coefficients may be complex numbers, and separate real and imaginary statistics and parameters are maintained. The statistic may be direction counts of the filter coefficient movement. The step size may be adjusted to a predetermined minimum value when the current direction of movement of the filter coefficient is different than the predominant direction and otherwise the step size is adjusted approximately proportionally to an amount of predominance by a value based on a direction count of the filter coefficient movement.

An adaptive filter includes a frequency domain adaptation block that analyzes a statistic of coefficient movement in the frequency domain. The adaption block adjusts, in the frequency domain, a parameter (step size or leakage factor) that affects speed of convergence of the adaptive filter based on the analyzed statistic of filter coefficient movement. The filter includes an associated coefficient, statistic of coefficient movement, and parameter for each frequency bin. The coefficients may be complex numbers, and separate real and imaginary statistics and parameters are maintained. The statistic may be direction counts of the filter coefficient movement. The step size may be adjusted to a predetermined minimum value when the current direction of movement of the filter coefficient is different than the predominant direction and otherwise the step size is adjusted approximately proportionally to an amount of predominance by a value based on a direction count of the filter coefficient movement.

A partitioned block frequency domain adaptive filter device includes a frequency domain adaptive filter configured for filtering a frequency domain representation of a time domain input signal depending on a set of filter coefficients consisting of a plurality of blocks of filter coefficients in order to produce a filtered signal; a plurality of parallel arranged filter update blocks; wherein each of the filter update blocks includes an adaptation module configured for executing an adaptation sequence including the steps of calculating an approximation of a constrained gradient update for the filter coefficients of the respective block of filter coefficients, and calculating a cumulative error introduced on the unconstrained gradient update; wherein each of the filter update blocks includes a correction module configured for executing a correction sequence including the steps of calculating a corrected constrained gradient update for the filter coefficients of the respective block of filter coefficients.

Techniques described herein provide cancelation of cross-polarization interference during simultaneous receipt of radiofrequency signals (e.g., an X-signal and a Y-signal) in a same frequency channel in nominally orthogonal polarizations. Though nominally orthogonally polarized, each signal contributes some cross-polarization interference to the other. Embodiments receive and demodulate each signal by a corresponding demodulator to generate corresponding X-symbol and Y-symbol decision signals, referenced to a common clock domain. An X-channel adaptive canceler (X-CAC) generates an X-output signal by using one or more Y-symbol decision signals adaptively to cancel cross-polarization interference from the Y-signal, and a Y-CAC generates a Y-output signal by using one or more X-symbol decision signals adaptively to cancel cross-polarization interference from the X-signal (e.g., the X-CAC and the Y-CAC each using a first-order least mean squares control loop). The resulting X-output signal and Y-output signal can be further decoded and output by the receiver to downstream systems and/or components.

Techniques described herein provide cancelation of cross-polarization interference during simultaneous receipt of radiofrequency signals (e.g., an X-signal and a Y-signal) in a same frequency channel in nominally orthogonal polarizations. Though nominally orthogonally polarized, each signal contributes some cross-polarization interference to the other. Embodiments receive and demodulate each signal by a corresponding demodulator to generate corresponding X-symbol and Y-symbol decision signals, referenced to a common clock domain. An X-channel adaptive canceler (X-CAC) generates an X-output signal by using one or more Y-symbol decision signals adaptively to cancel cross-polarization interference from the Y-signal, and a Y-CAC generates a Y-output signal by using one or more X-symbol decision signals adaptively to cancel cross-polarization interference from the X-signal (e.g., the X-CAC and the Y-CAC each using a first-order least mean squares control loop). The resulting X-output signal and Y-output signal can be further decoded and output by the receiver to downstream systems and/or components.

A partitioned block frequency domain adaptive filter device includes a frequency domain adaptive filter configured for filtering a frequency domain representation of a time domain input signal depending on a set of filter coefficients consisting of a plurality of blocks of filter coefficients in order to produce a filtered signal; a plurality of parallel arranged filter update blocks; wherein each of the filter update blocks includes an adaptation module configured for executing an adaptation sequence including the steps of calculating an approximation of a constrained gradient update for the filter coefficients of the respective block of filter coefficients, and calculating a cumulative error introduced on the unconstrained gradient update; wherein each of the filter update blocks includes a correction module configured for executing a correction sequence including the steps of calculating a corrected constrained gradient update for the filter coefficients of the respective block of filter coefficients.