Patent ID: 11921522

Abstract:
This disclosure is directed to sub-meter level navigation accuracy for Unmanned Aerial Vehicles (UAVs) using broadband communication signals, such as cellular long-term evolution (LTE) signals. A framework and methods are provided using a receiver and controller to produce at least one of carrier phase, code phase, and Doppler frequency measurements from received LTE signals. Single difference measurements may be used to remove clock bias. LTE ENodeB clock biases are initialized using the known initial position of the UAV. The measurements are fused via an extended Kalman filter (EKF) to estimate the UAV position and integer ambiguities of the carrier phase single difference measurements. LTE signals can have different carrier frequencies and conventional algorithms do not estimate the integer ambiguities. Processes are described to detect cycle slip, where the carrier phase measurements from the LTE eNodeB multiple antenna ports are used to detect cycle slip.