Abstract: A system for sensing, sampling and processing an input signal includes an encoding subsystem for sensing and sampling the input signal into a plurality of distinct data paths using a sub-Nyquist sampling rate. The system architecture is designed to induce encoded variations between the plurality of data paths, such as channel differences in amplitude or phase. The system additionally includes a decoding subsystem for reconstructing the encoded signal back to its original bandwidth. Preferably, the decoding subsystem exploits mismatch effects between the plurality of data paths as a form of signal diversity to resolve ambiguities introduced from sub-Nyquist signal sampling during signal reconstruction.

Abstract: A signal processing system for reducing calibration-related distortions in a complete-channel signal generated by a multi-channel subsystem, such as an interleaved ADC, includes a channel separator for separating the distorted digital signal into its various sub-channels and a single-channel corrector for independently processing each sub-channel to reduce distortion products present therein. The system additionally includes a subchannel re-combiner for combining the plurality of sub-channels processed by the single-channel corrector and a multi-channel corrector for calibrating each of plurality of sub-channels relative to one another to yield an equalized, complete-channel output signal. The multi-channel corrector includes a bank of optimized filters, each filter being assigned to a corresponding sub-channel of the complete-channel signal.

Abstract: A nonlinear equalizer for treating the nonlinear component of a distorted digital signal includes a first processing unit adapted to receive the distorted digital signal and yield an appropriate output signal in response thereto, a second processing unit adapted to receive the distorted digital signal and yield an appropriate output signal in response thereto, and a summation module for summing together the output signals from the first and second processing units so as to yield an equalized digital signal. In one embodiment, each of the first and second processing units comprises a linear filter, a partitioning filterbank for partitioning the distorted digital signal, and a multiplier for multiplying together the output of said linear filter with the output of said partitioning filterbank. In use, the nonlinear equalizer can be used to adaptively partition the distorted digital signal so as to allow for nonlinear equalization in a highly efficient manner.

Abstract: A method of nonlinear and affine signal processing includes the steps of introducing an input signal into a system which exhibits nonlinear behavior, the input signal including a target signal and a secondary signal. By virtue of its nonlinear design, the system generates nonlinear artifacts of the target signal and the secondary signal. These nonlinear artifacts are in turn used as a novel form of signal diversity. In one embodiment, the identification of the nonlinear artifacts is used to resolve defects that have been created as a result of sub-Nyquist sampling. In another embodiment, the identification of the nonlinear artifacts is used to locate and strengthen the power of a target signal that falls beneath the noise threshold for the system.