基于幅度振荡的天线圆周运动多径检测技术
Multipath detection based on signal amplitude oscillations with circularly rotating antenna

多径干扰是全球导航卫星系统（GNSS）高精度应用的主要误差来源之一。地球同步轨道（GEO）卫星在北斗全球系统中的应用导致了极低的多径衰落频率，致使大部分基于测量域的多径检测技术失效。该文提出了基于天线圆周运动的多径检测技术。通过控制天线转动参数，提高多径衰落频率从而使接收信号的幅度振荡在频谱中易于区分，以检测多径干扰。在基于GNSS信号源生成的多径场景实验中，所提方法能有效检测出低于直达信号30 dB的短时延多径干扰，且其性能优于基于载噪比（CNR）和码减载波（CMC）的多径检测方法。该方法大大缩短了多径检测时间，同时解决了GEO卫星多径检测问题。
Abstract：Multipath interference is the main error source in high-precision global navigation satellite system (GNSS) applications. The geosynchronous earth orbit (GEO) satellite in the BeiDou navigation satellite system (BDS) has extremely low fading frequencies on the multipath signals, so most measurement based multipath detection techniques are ineffective. This paper describes a multipath detection method based on a circularly rotating antenna. The rotating parameters are controlled to increase the multipath fading frequency so that it is separated from the spectrum of the received signals to facilitate detection. Tests use a GNSS signal generator to create the multipath environment. This method successfully detects a short delay multipath signal that is 30 dB lower than the direct signal. Its signal detection ability is then better than the carrier to noise ratio (CNR) and code minus carrier (CMC)-based multipath detection methods. This method dramatically reduces the detection time and solves the GEO multipath detection problem.