Demands for indoor positioning based services (IPS) in commercial and military fields have spurred many positioning systems and techniques. Complex electromagnetic environments (CEEs) may, however, degenerate the accuracy and robustness of some existing single systems and techniques. To overcome this drawback, fusion-based positioning of multiple systems and/or techniques have been proposed to revamp the positioning performance in CEEs. In this paper, we survey the fusion-based indoor positioning techniques and systems from seminal works to elicit the state of the art within our proposed unified fusion-based positioning framework, which consists of three fusion characteristics: source, algorithm, and weight spaces. Different from other surveys, this survey summarizes and analyzes the existing fusion-based positioning systems and techniques from three characteristics. Meanwhile, discussions in terms of lessons, challenges, and countermeasures are also presented. This survey is invaluable for researchers to acquire a clear concept of indoor fusion-based positioning systems and techniques and also to gain insights from this survey to further develop other advanced fusion-based positioning systems and techniques in the future.

中文翻译：

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基于融合的室内定位综述

商业和军事领域对基于室内定位的服务 (IPS) 的需求刺激了许多定位系统和技术。然而，复杂的电磁环境 (CEE) 可能会降低某些现有单一系统和技术的准确性和鲁棒性。为了克服这个缺点，已经提出了多个系统和/或技术的基于融合的定位来改进CEE中的定位性能。在本文中，我们从开创性工作中调查了基于融合的室内定位技术和系统，以在我们提出的基于融合的统一定位框架内引出最先进的技术，该框架由三个融合特征组成：源、算法和权重空间。与其他调查不同的是，本次调查从三个特点总结和分析了现有的基于融合的定位系统和技术。同时，也提出了经验教训、挑战和对策方面的讨论。这项调查对于研究人员获得基于室内融合的定位系统和技术的清晰概念以及从这次调查中获得见解以在未来进一步开发其他先进的基于融合的定位系统和技术是非常宝贵的。