发明名称 |
Method and apparatus for eliminating direct current offset |
摘要 |
The present invention provides a method and an apparatus for eliminating direct current offset. The method comprises the steps of: calculating Euclidean distances between every two demodulation symbols of a plurality of demodulation symbols based on Quadrature Phase Shift Keying (QPSK) modulation; determining four sets from the plurality of demodulation symbols in accordance with the Euclidean distances between the demodulation symbols, each set corresponding to a modulation direction for the QPSK modulation; performing Euclidean distance weighted summation on the determined four sets respectively, and selecting a demodulation symbol with the minimum weighted summation value from each set as a rough estimation point for the QPSK modulation, so as to obtain four rough estimation points; re-determining four sets from the plurality of demodulation symbols in accordance with the Euclidean distances between the demodulation symbols and the rough estimation points; performing Euclidean distance weighted summation on the re-determined four sets respectively, and selecting a demodulation symbol with the minimum weighted summation value from each set as a precise estimation point; and performing direct current offset calculation and compensation in accordance with the precise estimation points. The present invention can improve the demodulation performance of a system. |
申请公布号 |
US8964902(B2) |
申请公布日期 |
2015.02.24 |
申请号 |
US201113882761 |
申请日期 |
2011.11.14 |
申请人 |
ST-Ericsson Semiconductor (Beijing) Co., Ltd |
发明人 |
Chen Jiangshan;Ma Zhenguo;Yin Liyong |
分类号 |
H04L25/06;H04L27/22 |
主分类号 |
H04L25/06 |
代理机构 |
Patent Portfolio Builders PLLC |
代理人 |
Patent Portfolio Builders PLLC |
主权项 |
1. A method for eliminating direct current offset, comprising:
calculating Euclidean distances between every two demodulation symbols of a plurality of demodulation symbols based on Quadrature Phase Shift Keying (QPSK) modulation; determining four sets from the plurality of demodulation symbols in accordance with the Euclidean distances between the demodulation symbols, each set corresponding to a modulation direction for the QPSK modulation; performing Euclidean distance weighted summation on the determined four sets respectively, and selecting a demodulation symbol with the minimum weighted summation value from each set as a rough estimation point for the QPSK modulation, so as to obtain four rough estimation points; re-determining four sets from the plurality of demodulation symbols in accordance with the Euclidean distances between the demodulation symbols and the rough estimation points; performing Euclidean distance weighted summation on the re-determined four sets respectively, and selecting a demodulation symbol with the minimum weighted summation value from each set as a precise estimation point, so as to obtain four precise estimation points; and performing direct current offset calculation and compensation in accordance with the precise estimation points. |
地址 |
Beijing CN |