Radio Systems Group IMEC / Holst Centre, Eindhoven, the Netherlands

Mentor: Prof.dr.ir. Guido Dolmans Guido.dolmans@imec-nl.nl Guido.dolmans@tue.nl

Background

Bluetooth is an ideal wireless technology. It has developed over the years and as a result it is being used in many applications, although in some cases it presents some interesting challenges. One challenge is to find the location of a Bluetooth device. To date, the only feasible answer to locate a device without geo-positioning information is to estimate its distance from the receiver based on Received Signal Strength Indicator (RSSI) and RF transmit power.

Future versions of the Bluetooth specification will likely incorporate Angle-of-Arrival (AoA) and Angle-of-Departure (AoD) features which allow multi-antenna Bluetooth devices to determine the spatial location of another Bluetooth device. AoA and AoD will support high-accuracy location detection, potentially giving position accuracy to within tens of centimeters.

In the upcoming new Bluetooth standard, a device can make its direction available for a peer device by transmitting direction finding enabled packets. Using direction information from several transmitters and profile-level information giving their locations, a Bluetooth radio can calculate its own position.

The peer device, consisting of an RF switch and antenna array, switches antennas while transmitting. The receiver will captures IQ samples. The IQ samples can be used to calculate the phase difference in the radio signal received when switching between the various transmitt elements of the antenna array, which in turn can be used to estimate the angle of departure (AoD).

aoa

Figure 1: Bluetooth direction finding transmit-receive system

Project Description

In this MSc. thesis project, the direction finding capabilities of future generation Bluetooth devices will be further investigated. Requirements and specifications based on the latest draft Bluetooth standard will be set for a multi-antenna AoA/AoD system. A prototype system will be build, and the performance will be evaluated.

The project can be broadly divided in three main phases:

  1. Literature overview The student gets acquainted with the state of the art AoA/AoD systems, the relevant section from the Bluetooth standard, and studies the expected accuracy from literature.
  2. Project plan Using the literate overview, the student proposes a prototype system to be study in detail including a time-line.
  3. Building AoA/AoD prototype, test the performance, and compare with the initial expectations.

At the end of the project, the student is expected to produce a comprehensive project/MSc thesis report.

Candidate Background

The candidate is a Master’s student in Electrical Engineering, with a high affinity for and solid knowledge of signal processing for communications and localization. The candidate likes to work with electronic hardware prototypes. Knowledge of Matlab or C is required. Good spoken and written English is a must. Expected project duration is 9 months.

Location

The project will be carried out at Imec / Holst Centre at High Tech Campus 31, Eindhoven