I am currently designing a simple indoor location project to evaluate possibilities of Bluetooth 5.1 standard. The feature I would like to use is AoA (Angle of Arrival) introduced in Bluetooth 5.1.
According to the standard, AoA allows to measure position of a transmitting device (tx) by approximating the angle and measuring RSSI on a locator/receiver (rx). Since AoA is a feature newly implemented in 5.1, I understand that rx needs to support 5.1 Bluetooth standard. How about the transmitting device? What is the minimum version of Bluetooth it needs to support? Can I use 4.x BLE beacons (or Android/iOS devices simulating beacons) for this purpose?