The time-of-arrival (TOA) estimation method is an important ranging and positioning technology for indoor localisation and navigation. In this Letter, a novel TOA estimation method for smartphones based on a built-in microphone sensor is proposed, which utilises the propagation delay between optical and acoustic signals to achieve distance estimation. Unlike other TOA estimation technologies based on multi-sensors, a single MEMS microphone of a smartphone is used as the receiving sensor for both optical and acoustic signals, which is beneficial for eliminating the synchronisation error and improving ranging precision. Experimental results demonstrate that the proposed TOA estimation method is effective and accurate with an average ranging error of <0.29 m under a signal-to-noise ratio (SNR) of 1.18 dB for the smartphones tested in this work.

中文翻译：

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基于内置麦克风传感器的智能手机到达时间估计

到达时间（TOA）估计方法是用于室内定位和导航的重要测距和定位技术。在这封信中，提出了一种新的基于内置麦克风传感器的智能手机TOA估计方法，该方法利用光和声信号之间的传播延迟来实现距离估计。与其他基于多传感器的TOA估计技术不同，智能手机的单个MEMS麦克风被用作光学和声学信号的接收传感器，这有利于消除同步误差并提高测距精度。实验结果表明，对于这项工作中测试的智能手机，在1.18 dB的信噪比（SNR）下，所提出的TOA估计方法有效且准确，平均测距误差<0.29 m。