Method and apparatus for nonlinear signal processing include mitigation of outlier noise in the process of analog-to-digital conversion and adaptive real-time signal conditioning, processing, analysis, quantification, comparison, and control. Methods, processes and apparatus for real-time measuring and analysis of variables include statistical analysis and generic measurement systems and processes which are not specially adapted for any specific variables, or to one particular environment. Methods and corresponding apparatus for mitigation of electromagnetic interference, for improving properties of electronic devices, and for improving and/or enabling coexistence of a plurality of electronic devices include post-processing analysis of measured variables and post-processing statistical analysis.

The present disclosure relates to a concept of nonlinear signal processing which may be used for predistortion for RF power amplifiers. The concept includes generating time variant filter coefficients for a linear filter circuit based on a nonlinear mapping of an input signal, and filtering the input signal with the linear filter circuit using the time variant filter coefficients in order to generate a filtered output signal. Thus, it is proposed to implement a non-linear filter by a time-varying linear filter where the time-varying coefficients are derived from the input signal.

Provided is a digital filter device including data rearrangement means for executing rearrangement of input data and outputting rearranged data, intermediate data calculation means for processing the rearranged data input at a specific time and generating intermediate data, filter output first calculation means for calculating a first output value at the specific time by use of the intermediate data, delay means for delaying the rearranged data by processing time taken in the intermediate data calculation means and the file output first calculation means, and filter output second calculation means for inputting output values from the delay means and the filter output first calculation means, calculating a second output value at a time other than the specific time, and outputting a filter output value obtained by adding up the first and second output values. Consequently, it becomes feasible to reduce a circuit scale without impairing performance of a digital filter used in nonlinear compensation and realize nonlinear compensation by an LSI.

A nonlinear compensator is provided to include a decomposition circuit and a plurality of filter elements. The decomposition circuit has a nonlinear frequency response characteristic and the decomposition circuit is configured to receive an input signal and decompose the input signal into decomposed signals corresponding to positive and negative frequency signal components of the input signal. Each of the plurality of filter elements is configured to receive at least portions of the decomposed signals and apply filter element characteristics to the decomposed signals with the filter element characteristics that are matched to the nonlinear frequency response of the decomposition circuit.

A method is provided. The method comprises: initializing at least one non-linear filter configured to provide at least one predictive measurement estimate probability density function; obtaining measurement data; determining if the measurement data is consistent; and if the measurement data is consistent, then estimating at least one state parameter with the at least one non-linear filter using the measurement data.

A filter can be used in circuit. The filter includes a first stage including a first resonator configured to oscillate at a first fundamental frequency, a second resonator configured to oscillate at a second fundamental frequency, and a first nonlinear coupler for the first resonator and the second resonator. The second fundamental frequency being one half of the first fundamental frequency. The filter also includes a second stage including a third resonator, a fourth resonator, and a second nonlinear coupler for the third resonator and the fourth resonator.

A method is disclosed for efficiently calculating a median value of a high-order array in a Single Instruction Multiple Data (SIMD) processor. Values of the high-order array are sorted vertically in each column followed by sorts on each individual row. After the sort, selective diagonal values of the sorted high-order array are used to form a low-order array to calculate the median of the high-order array. The median calculation using selective diagonal values of the high-order array in a low-order array significantly improves SIMD processor efficiency and throughput.

A multi-rate filter system is disclosed. More particularly, a computationally efficient multi-rate filter system for processing an audio stream on a consumer electronics device is disclosed. The multi-rate filter system includes a plurality of multi-rate filtering blocks, at least one block including a linear filter component. At least one multi-rate filtering block may include a nonlinear signal processing component. The multi-rate filter system may include a nonlinear functional block. A method of filtering a signal is also disclosed.

A filter apparatus (100) having a signal input (101) to which an input signal is applied which contains a useful component and a noise component, a fast signal path (102) and a slow signal path (103) arranged in parallel therewith. The fast signal path and the slow signal path are coupled to the signal input. The fast signal path contains a filter in order to prompt fast filtering of the input signal. The slow signal path contains a filter in order to prompt slow filtering of the input signal. An output of the slow signal path is coupled to the fast signal path by means of a signal line (106). A signal output (104) which is coupled to the fast signal path has an output signal applied to it which essentially contains useful components of the input signal.

Aspects and embodiments are directed to non-linear systems including a digital compensator structure, a method of digital compensation, and methods for designing digital compensator structures for analog receivers. A digital compensator is configured to substantially reduce the one or more nonlinear distortion components in the sampled digital output signal from the analog receiver to provide an output signal achieving a receiver linearity requirement for the combination of the analog receiver and a digital compensator.