Method and apparatus for improving communication system performance in Tomlinson Harashima Precoding (THP) mode with a zero edge filter

摘要

An improved Tomlinson Harashima Precoding (THP) communication system through special configuration of its feedback coefficients is disclosed. Improvement, in terms of THP system robustness against analog-to-digital (ADC) sampling phase variation, is achieved either by deriving feedback coefficients of the Decision Feedback Equalizer at worst ADC sampling phase or by inserting a Zero Edge Filter (ZEF) at the receiver. The ZEF modifies the communication system such that the feedback filter coefficients derived in the Decision Feedback Equalizer (DFE) mode and later used in the THP mode is capable to compensate the zero at Nyquist Frequency due to a non-optimum sampling, phase of the ADC. The THP communication system, modified and improved with the insertion of ZEF, is operable to switch from an adaptive Decision Feedback Equalizer (DFE) mode to a THP mode having an adaptive Linear Equalizer (LE) at the receiver.