Array signal processing is attractive for Global Navigation Satellite System (GNSS) applications, as the desired reception environments for GNSS are becoming more challenging, while users’ demands for high-accuracy positioning are growing. One goal of array signal processing is to find the direction of arrival (DOA) of the signal source. Several advanced techniques have been proposed to estimate the DOA, with the direction lock loop (DiLL) being a representative method. However, applying the DiLL in GNSS receivers is not straightforward. One reason for this is the low sensitivity of the utilized spatial correlation function in the angular region close to broadside within a linear antenna array. In order to address this problem, an improved DOA tracking technique is presented building on the traditional DiLL, i.e., the rotate-to-zero direction lock loop (RZ-DiLL). Simulations and live data validations show that the proposed RZ-DiLL avoids the low sensitivity issue of the traditional DiLL. Moreover, the experimental results show that compared to a single-antenna GNSS receiver, the RZ-DiLL-implemented GNSS array signal receiver provides an improved carrier-to-noise ratio and, in turn, improved position solutions.

中文翻译：

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使用旋转至零方向锁定环进行GNSS到达方向跟踪

阵列信号处理对于全球导航卫星系统（GNSS）应用很有吸引力，因为所需的GNSS接收环境正变得越来越具有挑战性，而用户对高精度定位的需求也在不断增长。阵列信号处理的一个目标是找到信号源的到达方向（DOA）。已经提出了几种先进的技术来估计DOA，其中方向锁定环（DiLL）是一种代表性方法。但是，在GNSS接收机中应用DiLL并非易事。原因之一是线性天线阵列内靠近宽边的角区域中所利用的空间相关函数的灵敏度低。为了解决这个问题，在传统DiLL的基础上提出了一种改进的DOA跟踪技术，即 零旋转方向锁定环（RZ-DiLL）。仿真和实时数据验证表明，提出的RZ-DiLL避免了传统DiLL的低灵敏度问题。此外，实验结果表明，与单天线GNSS接收器相比，RZ-DiLL实现的GNSS阵列信号接收器提供了改进的载噪比，进而改进了位置解。