LTH-image

Joint Positioning and Radio Channel Estimation

Researchers:Bo Bernhardsson, Anders Mannesson

Funding: VR

 

The project works with algorithms to combine information from gyros, accelerometers and compass sensors with radio channel estimation and to determine the fundamental properties of such schemes. The hope is to enable two technology advancements:

  • a new method for significantly reduced drift in low cost navigation systems
  • improved radio channel estimation for moving terminals, suitable for MIMO systems

 

Initial research show promising result as presented in the licentiate thesis by Anders Mannesson and in this presentation

The work is based on angle of arrival estimation using antenna arrays which is a well studied problem with many different algorithms resolving the individual rays impinging on the array. However, less attention has been given to so called virtual array antennas where moving receiver elements are used. By tracking the movement of the element, an array with properties similar to a stationary array with multiple elements is formed. By combining the IMU and the radio channel information, a map of the local radio environment can be obtained, such as in this picture illustrating the complex valued radio channel for three impinging planar radiowaves in a noise-free situation

Tightly coupled nonlinear state estimation algorithms between IMU signals and radio channel estimates are used to simultaneously estimate this map and obtain improved pose estimates.

The major challenge is to battle the drift in sensors and radio crystal oscillators. We work with both real-world measurements and simulations to evaluate performance. Initial experiments show promising results. The following figure shows performance (simulations left, real experiments right) with realistic radio and IMU imperfections. There is a dramatic improvement by including radio channel information compared to using dead reckoning, especially for movements longer than 10 seconds.

Our future research now focuses on improving radio channel estimation and prediction by adding IMU information and using motion models.

Publications

Anders Mannesson, Muhammad Atif Yaqoob, Bo Bernhardsson, Fredrik Tufvesson: "Tightly Coupled Positioning and Multipath Radio Channel Tracking". IEEE Transactions on Aerospace and Electronic Systems, pp. 1522–1535, 2016.

Anders Mannesson: Joint Positioning and Multipath Radio Channel Estimation and Prediction. PhD Thesis TFRT-1113, Department of Automatic Control, Lund University, Sweden, March 2016.

Muhammad Atif Yaqoob, Anders Mannesson, Naveed R. Butt, Fredrik Tufvesson: "Source Localization Using Virtual Antenna Arrays". In: 2015 International Conference on Localization and GNSS (ICL-GNSS) 2015.

Anders Mannesson, Bo Bernhardsson, Muhammad Atif Yaqoob, Fredrik Tufvesson: "Optimal Virtual Array Length Under Position Imperfections". In: 2014 IEEE 8th Sensor Array and Multichannel Signal Processing Workshop (SAM) 2014.

Anders Mannesson: "Joint Pose and Radio Channel Estimation". Licentiate Thesis Department of Automatic Control, Lund University, Sweden, June 2013.

Anders Mannesson, Muhammad Atif Yaqoob, Bo Bernhardsson, Fredrik Tufvesson: "Radio and IMU based indoor positioning and tracking". In: 2012 19th International Conference on Systems, Signals and Image Processing (IWSSIP) 2012.


2017-02-09