No, I meant both the controller and drones radio use the CDMA modulation technique to transmit at power levels imperceptibly above the background noise levels.

No, I meant both the controller and drones radio use the CDMA modulation technique to transmit at power levels imperceptibly above the background noise levels. A listener would only hear white noise and would not even know the drone/controller are transmitting. (This is after all what CDMA spread spectrum modulation was invented by Hedy Lamar for) Absolutely nothing to do with the W-CDMA telephone system.