BLE AoA technology

First talk about Bluetooth, originated from Nokia, the early is based on voice transmission, later development, there is a tendency to

go to data, and more and more complex, after Bluetooth 3.0, it did not continue to evolve. Switch to the Bluetooth Low Energy (BLE)

direction. BLE after nearly a decade of development, to the current BLE5.1 support for AoA (Angle of Arrival) feature.

BLE AoA is an array of antennas for precise positioning

Therefore, in the BLE AoA positioning system, the most core is the accuracy of the array antenna of the base station to the Angle

sampling, from all the samples on the market at present, the best is about 2 degrees. Another parameter that can be used for

positioning reference is signal strength.

BLE AoA positioning has the following characteristics:

1. Multi-dimensional support

Zero-dimensional positioning: can be done, not recommended, because a single base station can complete two-dimensional

positioning;

One-dimensional positioning: can be done, not recommended, because one-dimensional positioning is completely based on the signal

strength to determine the location of the target between the two base stations;

2D positioning: recommended;

3D positioning: can be done;

2, positioning accuracy

In the case of no occlusion, the deployment distance of the base station is relatively close, such as 5 meters away, and the positioning

accuracy can achieve similar results to UWB;

3, low cost, long standby

The cost of BLE tag is relatively low, because the tag only needs to send the Beacon message, and the server can locate it after the

base station receives it, and its standby time is relatively long. Since the cost of BLE chip is much lower than that of UWB, its tag cost

and standby time are far better than that of UWB.

1. Accuracy is susceptible to disturbance

BLE AoA positioning, mainly based on Angle positioning, is not suitable for complex environments, especially in the factory there are

many metal scenes, the base station is affected by the multi-path will lead to Angle identification errors, resulting in poor accuracy;

2, base station deployment distance and height

The positioning accuracy is affected by the deployment distance of the base station, because the farther the label is from the base station,

the greater the error, such as 5/10/20 meters, if the Angle accuracy is 3 degrees, then

Radius (m) 5, 10, 20

Circumference (m) 31.4 62.8 125.6

Deviation (m) 0.25 0.5 1

In addition, it is affected by the installation height of the base station, and there is also the problem of black lights.