| Carl Friedrich Gauß Faculty | Department of Computer Science
InPhase Sensor Node

InPhase Sensor Node

InPhase: Phase-based Ranging and Localization

The position of persons or goods in 3D space is a crucial information for different types of applications. In the realm of Wireless Sensor Networks (WSNs), the position of individual sensor nodes can be exploited to enable applications like location-based routing or positioning of vehicles. Most Real-Time Locating Systems (RTLS) are based on measurements of Received Signal Strength Indication (RSSI), Time-of-Flight (ToF) or Angle-of-Arrival (AoA). This often requires additional hardware.

InPhase does not require additional hardware except for a radio transceiver with integrated Phase Measurement Unit (PMU). The system determines the distance between pairs of nodes in the sensor network. By adding nodes with known positions to the network, the absolute 3D position of a sensor node can be computed.

Currently, the system employs the AT86RF233, an IEEE 802.15.4 radio transceiver. This chip by Atmel (Microchip) features an integrated PMU to measure the phase angle of an incoming radio wave. This extra information allows to determine the distance between sender and receiver. InPhase implements the execution of such a phase measurement. The resulting phase data is used to compute the distance between the two devices. Additionally, we investigated the quality of the measurement data in different environmental conditions.

Measured Phase Data

Measured Phase Data

To allow easy integration of InPhase into other applications, the network protocol and algorithm are implemented based on the Contiki operating system by Dunkels et al. We use different variants of the INGA wireless sensor node as hardware platform. Additionally, we developed a PC software that allows to initiate measurements and to evaluate the obtained measurement data. This software also implements positioning via a Particle Filter. To mitigate the effect of errorneous measurements, the software uses additional metrics to determine the quality of a distance measurement.

Localization via Particle Filter

Localization via Particle Filter


Poster NLOS-aware Localization Based on Phase Shift MeasurementsA Test Environment for Phase-Based Ranging and LocalizationInPhase: No-Cost Phase-Based Ranging and Localization


Project members at IBR

Yannic Schröderschroeder[[at]]ibr.cs.tu-bs.de+49-531-3913249134
Prof. Dr.-Ing. Lars Wolfwolf[[at]]ibr.cs.tu-bs.de+49-531-3913288138


Analyse und Verbesserung des InPhase-SystemsBachelor Thesis, Master Thesis, Project ThesisYannic Schröderopen
Parallelisierte Messung von Phasengängen zur LokalisationMaster ThesisYannic Schröderrunning
Analyse von phasenbasierten Entfernungsmessungen bei Nicht-Sichtverbindungen und MehrwegeausbreitungMaster ThesisYannic Schröderrunning
Modularization and Generalization of the InPhase-System for Different PlatformsMaster ThesisYannic Schröderrunning
InPhaseMaster ThesisDr. Felix Büsching, Stephan Rottmann, Georg von Zengenfinished
Einfluss der Antennen, ihrer Ausrichtung und von Reflexionen auf die Genauigkeit des InPhase-SystemsBachelor ThesisYannic Schröderfinished
Implementation and evaluation of a particle filter for the InPhase systemMaster ThesisYannic Schröder, Dr. Felix Büschingfinished
Analyse des InPhase-Systems zur Verbesserung von Präzision und GenauigkeitMaster ThesisYannic Schröderfinished
Implementierung von Software- und Systemtests für das InPhase-SystemProject ThesisYannic Schröderfinished
Statistical approach for the InPhase positioning systemBachelor ThesisYannic Schröder, Georg von Zengen, Stephan Rottmannfinished

If you are interested in writing a thesis regarding this project, please feel free to contact Yannic Schröder.

last changed 2019-03-06, 10:49 (dynamic content) by Yannic Schröder