关键词: 直放站, 回波抵消, 盲信号分离, 独立分量分析, 相空间重构, 全球移动通信系统

Abstract: An echo cancellation method on digital repeater of mobile communication system was presented to solve the problem of traditional adaptive filter, which cannot eliminate the sub-path echo in complex multipath channel. Firstly, based on phase space reconstruction theory, the signal that came from the donor antenna and contained echo was reconstructed; hence, the number of sensors was not fewer than the number of sources in blind source separation. Secondly, Independent Component Analysis (ICA) algorithm was used to separate reconstructed signal. Finally, desired signal was determined by the correlation of sent signal and separated signal. In the experiment on the multi-carrier Global System of Mobile communication (GSM) source with complex multipath echo, correlation coefficient of desired signal was up to 0.9593. The echo cancellation method based on blind source separation proves to be an effective way to eliminate the echo in complex multipath channel.

Key words: repeater, echo cancellation, blind source separation, Independent Components Analysis （ICA）, phase space reconstruction, Global System of Mobile communication （GSM）