Abstract
Recently, with rapid proliferation of mobile communication, there has arisen a need for adaptive array antennas that can automatically control the antenna radiation pattern. In adaptive array antennas based on the MMSE (Minimization of Mean Square Error) method, a reference signal with a high correlation with the desired wave is required in order to distinguish the desired wave and the interference waves. The unique word (UW) employed for synchronization in mobile communication is a known signal sequence and can be used as a reference signal. However, it is necessary to accurately estimate the timing at which the UW is contained in the communication signal. The estimation error in the case of strong interference can be a cause of deterioration of the interference suppression capability. Also, if the UW is contained in both the interference and the desired wave at the same timing, the desired wave cannot be recognized and the interference wave cannot be suppressed. In this paper, an adaptive array antenna with a twoβstage configuration using a preprocessing of an SLC (sidelobe canceler) is proposed so that the effect of the interference prior to the start of communication is avoided. By the simulation, it is confirmed that only the interference wave can be suppressed effectively even if the UWs contained in the interference and the desired wave are in synchronization. Β© 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(7): 1β11, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1106