How does Bluetooth direction finding work?
Bluetooth direction finding uses angle-of-arrival (AoA) technology to calculate the angle at which the RF signal transmitted by the moving tag hits the anchor. It does so by measuring slight phase differences of the incoming Bluetooth advertising message across the anchor’s multi-antenna array.
Can Bluetooth detect direction?
Bluetooth Direction Finding By identifying the angle of signal arrival at the receiver’s end or determining the angle of signal departure at the transmitter’s end, a Bluetooth device can determine direction and signal accuracy down to the centimeter level.
What is AoD AoA?
The new Bluetooth® direction finding feature supports two methods for determining the direction of a Bluetooth signal, both of which are based on the use of an antenna array: angle of arrival (AoA) and angle of departure (AoD).
How does angle of arrival work?
AoA stands for Angle of Arrival is based on the principle of measuring angular directions (Azimuth and Elevation) from a device (aka Locator) placed at a known location. With angle it is meant the angle in which the signal meets the receiver. The angle is measured by computing the phase of the receiving radio signals.
What is RSSI Bluetooth?
RSSI (Received Signal Strength Indicator) For Bluetooth, it is the strength of the beacon’s signal as seen on the receiving device, e.g. a smartphone. The signal strength depends on distance and Broadcasting Power value.
How does Bluetooth determine distance?
Beacon technology generally estimates the distance between devices using the received signal strength (RSSI). Localization of Bluetooth devices is done by combining the distance estimate to several beacons, mounted at fixed and known locations, using triangulation with at least 3 anchors.
How does AoA Ble work?
Angle of Arrival (AoA) The peer BLE device consisting of an RF switch and an antenna array switches antennas and captures the received in-phase (I) and quadrature (Q) samples. The BLE device uses these I and Q samples to compute the phase difference in the radio signal received by various elements of the antenna array.
How do you find the angle of arrival?
The AoA can be calculated by measuring the time difference of arrival (TDOA) between individual elements of the array. Generally this TDOA measurement is made by measuring the difference in received phase at each element in the antenna array. This can be thought of as beamforming in reverse.
How do you find the angle of departure?
Angle of Departure is equal to: θdepart = 180° + sum(angle to zeros) – sum(angle to poles). θdepart = 180° + 90 – 135.
What is the advantage of angle of arrival for estimating location?
An advantage of AOA-based techniques is that they do not require clock synchronization; however, accurate angle measurements may require directional antennas, multiple-element antenna arrays, and possibly computationally expensive array processing algorithms.
How accurate is ble RSSI?
As part of the broadcast message decoding, the BLE software stacks return the Received Signal Strength Indicator (RSSI) value. This value can be used to approximate distance and when measurements from multiple devices are combined, the device position can be estimated with accuracy of 1 to 4 meters (3 to 12 feet).
How do I test my Bluetooth RSSI?
Simply Option (Alt) click the Bluetooth menu bar item, then move the mouse cursor over the Bluetooth item you want to check the signal strength for and look for “RSSI”. The two most likely reasons for a bad Bluetooth connection are low batteries and heavy interference from something in the environment.
What is the purpose of the Bluetooth working group?
This group of dedicated individuals works to develop new Bluetooth specifications and enhance adopted ones—specifications that make Bluetooth the fastest growing wireless technology on the planet. Participating in SIG Working Groups and Committees holds different benefits for each member.
Who is the developer of Bluetooth direction finding?
In this comprehensive overview, Bluetooth ® Developer Relations Manager Martin Woolley examines the new direction finding feature included in the latest version of the Bluetooth Core Specification.
How does direction finding work with Bluetooth Low Energy?
Bluetooth ® Direction Finding enables devices to determine the direction of a Bluetooth Low Energy (LE) signal, thereby enabling the development of Bluetooth proximity solutions that can understand device direction as well as Bluetooth positioning systems that can achieve centimeter-level location accuracy.
How is the direction of a Bluetooth signal determined?
Bluetooth Direction Finding includes two different methods for determining signal direction, Angle of Arrival (AoA) and Angle of Departure (AoD). In the Angle of Arrival (AoA) method, a transmitting device, such as an asset tag in a Real Time Locating System (RTLS) solution, uses a single antenna to transmit a special signal.