Indoor Mobile Device Location Using BLE and Particle Filter

The patent introduces BLE signals as an intermediary medium that can penetrate building structures effectively. Instead of relying on GPS or cellular signals that fail indoors, the system uses BLE beacons deployed inside buildings to provide location information. The mobile device communicates with these internal beacons to determine its position, thus resolving the signal penetration problem and enabling reliable indoor location services.

The patent changes the fundamental parameter of signal type from traditional GPS/cellular signals to BLE signals. This parameter change is critical because BLE signals have different propagation characteristics that allow them to penetrate building materials effectively. By changing the signal parameter, the system adapts to indoor environments where traditional signals fail, thereby improving both reliability and indoor adaptability simultaneously.

The patent segments the location service system into multiple functional components: BLE beacons deployed at specific locations, mobile devices with sensors, a particle filter algorithm, and a fingerprint database. This segmentation allows each component to perform its specific function optimally - beacons provide signal references, sensors capture movement data, the particle filter processes information, and the database stores reference data. This modular approach improves measurement precision while keeping individual components relatively simple.

The patent replaces traditional outdoor LBS mechanisms (GPS satellite signals and cellular network triangulation) with an indoor-specific mechanism combining BLE signals, inertial sensors, and computational algorithms. This substitution is necessary because the old mechanical/signal-based system cannot penetrate buildings, while the new system using electromagnetic BLE signals and sensor data fusion can achieve accurate indoor positioning despite the increased computational complexity.