METHOD AND APPARATUS FOR ELIMINATING DIRECT CURRENT OFFSET

摘要

Disclosed are a method and an apparatus for eliminating direct current offset. The method comprises the following steps: calculating Euclidean distances between every two demodulation symbols in multiple demodulation symbols based on Quadrature Phase Shift Keying (QPSK) modulation; determining four sets from the multiple demodulation symbols, wherein each set corresponds to a modulation direction for the QPSK modulation; performing Euclidean distance weighted summation calculation for the determined four sets respectively, and selecting the demodulation symbol with the minimum weighted summation value in each set as a rough estimation point of the QPSK modulation; redetermining four sets from the multiple demodulation symbols according to Euclidean distances between the demodulation symbols and the rough estimation points; performing Euclidean distance weighted summation calculation for the redetermined four sets respectively, and selecting the demodulation symbol with the minimum weighted summation value in each set as a precise estimation point of the QPSK modulation; performing direct current offset calculation and compensation according to the precise estimation points. The present invention can improve the demodulation performance of a system.