BLE AoA/AoD is the key feature of Core Spec 5.1, it is to enhance the positioning service, comparing with previous RSSI based positioning.

Bluetooth Core SPEC5.1 adopt AoA/AoS, which could detect the direction of the beacon signal. With this technology, access solutions could find the direction of the devices and could locate the device to centimeter level.

Radio direction finding has been used since the beginning of the 20th century, and it has been very mature. It was applied in various fields, from navigation to wildlife tracking. Now, Bluetooth direction finding brings this technology to one of the most trusted and widely used wireless communication technologies in the world: BLE.

Bluetooth direction finding includes two methods: AoA and AoD(Angle of Arrival, Angle of Departure).

The phase difference of the radio wave reaching multiple antennas is related to the direction of arrival. The direction of arrival is inferred from the phase of the radio, which is the principle of the angle of arrival. Similarly, by inverting the relationship between receiving and transmitting, and deducing the transmitting direction of radio wave through phase characteristics, this called AoD.

With multiple antenna arrays to measure the direction from the target to the antenna array, the coordinates of the target in three-dimensional space could be calculated, as shown in Figure.

Assuming that the target is on a two-dimensional plane, one antenna array could be used to measure the direction of the target, and the two-dimensional coordinates of the target can be calculated, as shown in Fig.

BLE AoA/AoD positioning will play an important role in different scenarios such as item tracking, indoor navigation, etc.

Ingchips provides BLE 2D/3D positioning total solutions including SoC, antenna array, direct find algorithm, positioning algorithm, and reference backend architecture.

More：

Application Note: Direction Finding Solution (https://ingchips.github.io/application-notes/an_aoa/index.html)

Application Guide: BLE Positioning Solution(https://ingchips.github.io/application-notes/an_aoa_positioning_cn/index.html)