## Estimate Bluetooth LE Node Position

Bluetooth® Toolbox features enable you to estimate the 2-D or 3-D position of a Bluetooth low energy (LE) node by using lateration, angulation, or distance-angle localization methods.

### Estimate Bluetooth LE Receiver Position in 3-D Network Using Lateration

Set the positions of the Bluetooth LE transmitters (locators).

```txPosition = [-5 -15 -30 -12.5;8.6603 -15 -17.3205 -21.6506; ... -17.3205 21.2132 20 43.3013]; % In meters```

Specify the distance between each Bluetooth LE transmitter and receiver.

`distance = [13.2964 33.4221 40 55.0728]; % In meters `

Specify the localization method. Because the distance between each Bluetooth LE transmitter and receiver is known, set the localization method to `'lateration'`.

`localizationMethod = "lateration";`

Estimate the position of the Bluetooth LE receiver. The actual position of the Bluetooth LE receiver is [-7.5, 4.33, -5].

```rxPosition = blePositionEstimate(txPosition,localizationMethod, ... distance)```
```rxPosition = 3×1 -7.5001 4.3304 -4.9999 ```

### Estimate Bluetooth LE Transmitter Position in 2-D Network Using Angulation

Set the positions of the Bluetooth LE receivers (locators).

`rxPosition = [-18 -40;-10 70]; % In meters`

Specify the azimuth angle of the signal between each Bluetooth LE receiver and transmitter.

`azimuthAngles = [29.0546 -60.2551]; % In degrees`

Specify the localization method. Because the angle of the signal between each Bluetooth LE receiver and transmitter is known, set the localization method to `'angulation'`.

`localizationMethod = "angulation";`

Estimate the position of the Bluetooth LE transmitter. The actual position of the Bluetooth LE transmitter is at the origin: (0, 0).

```txPosition = blePositionEstimate(rxPosition,localizationMethod, ... azimuthAngles)```
```txPosition = 2×1 10-4 × 0.2374 0.1150 ```

### Estimate Bluetooth LE Transmitter Position in 3-D Network Using Distance-Angle

Set the position of the Bluetooth LE receiver (locator).

`rxPosition = [-10; 30; 40]; % In meters`

Specify the distance between the Bluetooth LE receiver and transmitter.

`distance = [23.2964]; % In meters`

Specify the azimuth and elevation angles of the signal between the Bluetooth LE receiver and transmitter.

`direction = [29.0546; -20.2551]; % In degrees`

Specify the localization method. Because the distance and angle of the signal between the Bluetooth LE receiver and transmitter is known, set the localization method to "`distance-angle`".

`localizationMethod = "distance-angle";`

Estimate the position of the Bluetooth LE transmitter. If one receiver (locator) is present in the range of a Bluetooth LE transmitter, the "`distance-angle`" localization method estimates the location of the transmitter by using both of these measurements.

• Angle of arrival (AoA) or angle of departure (AoD) of a direction finding signal

`txPosition = blePositionEstimate(rxPosition,localizationMethod,distance,direction)`
```txPosition = 3×1 9.1054 40.6141 31.9348 ```

## References

[1] Bluetooth Technology Website. “Bluetooth Technology Website | The Official Website of Bluetooth Technology.” Accessed November 22, 2021. https://www.bluetooth.com/.

[2] Bluetooth Special Interest Group (SIG). "Bluetooth Core Specification." Version 5.3. https://www.bluetooth.com/.