Multipath Mitigation for Indoor Localization Based on IEEE 802.11 Time-of-Flight Measurements
There are two major approaches to wireless LAN based indoor localization. One is based on Received Signal Strength Indication (RSSI). The other one measures the Time Of Flight (TOF), i.e. the time a network frame needs for propagation in space. To both methods multipath effects pose a significant problem. A well-known mitigation approach for RSSI-based methods is location fingerprinting. This paper investigates the application of fingerprinting to TOF-based localization. In addition, the authors provide a comparison of RSSI- and TOF-based approaches by applying the same algorithms under the same conditions. Finally, they demonstrate that fingerprinting improves TOF-based localization accuracy and even allows for a RSSI-TOF-hybrid approach with low additional effort.