Indoor Positioning System (IPS) is a crucial technology that enables medical staff and hospital managements to accurately locate and track persons or assets inside the medical buildings. Among other technologies, Bluetooth Low Energy (BLE) can be exploited for achieving an energy-efficient and low-cost solution. This work presents the design and implementation of an received signal strength indicator (RSSI)-based indoor localization system. The paper shows the implementation of a low complex weighted k-Nearest Neighbors algorithm that processes raw RSSI data from connection-less iBeacon's. The designed hardware and firmware are implemented around the low-power and low-cost nRF52832 from Nordic Semiconductor. Experimental evaluation with the real-time data processing has been evaluated and presented in a 7.2 m by 7.2 m room with furniture and 5 beacon nodes. The experimental results show an average error of only 0.72 m in realistic conditions. Finally, the overall power consumption of the fixed beacon with a periodic advertisement of 100 ms is only 50 uA at 3 V, which leads to a long-lasting solution of over one year with a 500 mAh coin battery.

翻译：室内定位系统（IPS）是一项关键技术，使医护人员及医院管理者能够精准定位并追踪医疗建筑内的人员或资产。在众多技术中，低功耗蓝牙（BLE）可用于实现高能效、低成本的解决方案。本文提出并实现了一种基于接收信号强度指示（RSSI）的室内定位系统，展示了采用低复杂度加权k近邻算法处理来自无连接iBeacon的原始RSSI数据的设计方法。系统硬件与固件围绕Nordic Semiconductor的低功耗低成本芯片nRF52832实现。基于实时数据处理的实验评估在7.2米×7.2米、配备家具及5个信标节点的房间内进行。实验结果表明，在真实环境下平均定位误差仅为0.72米。此外，固定信标在100毫秒周期性广播下的整体功耗仅为3V电压下50微安，采用500毫安时纽扣电池可实现超过一年的长效运行。