Is wifi/bluetooth Triangulation(not trilateration) using a mobile device possible?

Question

Well for triangulation you need to have the direction from which your device is receiving the signal.We can calculate Angle of Arrival for that but calculating that angle requires an array of receivers. Is a cell phone capable of calculating Angle of Arrival? I am asking this because I have came across the terms like wifi/BLE triangulation, calculating position by triangulation etc but they're actually referring to Trilateration in most of the cases. I know how trilateration works for a mobile and all the details but I don't think Triangulation is possible. And if it is possible, how is it possible and which one (triangulation or trilateration) is expected to give better result if you use ibeacons to approximate positions?

Answer 1

Lot of people are misleading terms as you pointed out. Triangulation is not possible with standard ble beacons or WiFi (I mean without modify the standard ble 4.0 or 4.1 and WiFi) right now because the standard doesn't report useful information like the phase (if you have phase and an array of directional antennas that are powered on one per time at a predetermined frequency you can use algorithms like MUSIC and deal with angles) but we only have Rssi and TX power at one meter(if it's an iBeacon) with those information we can estimate the distance that is very imprecise and fluctuate rapidly over time because of multipath and diffraction. In Nextome we have invented an algorithm to mitigate multipath fading that causes signal to bounce and achieve high accuracy Indoor Positioning of about 1 meter without fingerprinting. No one has tested triangulation with standard iBeacons right now but trilateration. I would start looking at least square approximation to solve the trilateration problems, but don't expect big results without filtering out the noise.