Method and Apparatus for Complex In-Phase/Quadrature Polyphase Nonlinear Equalization

The demand for quality digital transmissions has grown significantly with the rise of high-frequency trading, telecommunications, and multimedia technologies. Clever conversion from analog to digital is crucial to servicing these sectors. Among these methods, complex in-phase/quadrature (I/Q) time-interleaved analog-to-digital converters (TIADCs) are widely utilized. However, they inherently produce nonlinear distortions, compromising the quality of the resulting digital waveform. The challenge with existing solutions is that they typically struggle to eliminate completely these nonlinear distortions stirring from TIADCs. This shortcoming compromises system performance, produces imprecise data, and reduces the efficiency of subsequent processing stages. The technology operating at the conversion juncture hence becomes a critical factor in resolving the quality of resulting digital waveforms.

Technology Description

Complex polyphase nonlinear equalizers (cpNLEQs) serve as a corrective tool for distortions generated by complex in-phase/quadrature (I/Q) time-interleaved analog-to-digital converters (TIADCs). The cpNLEQs upsample the digital waveform produced by the TIADC, for example, by a factor of two, thereafter separating it into upsampled in-phase and quadrature components. Processors within the cpNLEQs manufacture real and imaginary nonlinear compensation terms from these upsampled elements. The standout features of cpNLEQs rest in their ability to downsample the compensation terms, phase-shift the downsampled imaginary component, and combine it with the downsampled real component. This process produces an estimated residual distortion. Subtraction of this distortion from the originating digital waveform emitted by TIADC results in an equalized digital waveform fit for further processing, setting cpNLEQs apart by materially enhancing the quality and reliability of digital waveforms.