US Patent 10578743 System and method of location determination using multiple location inputs

Systems and methods of determining a device position are described. GPS and cellular signals, in addition to VIO displacement are used to determine the device position via a loose or tight coupling algorithm. Both algorithms iteratively linearize base station position equations around an intermediate position that changes each iteration based on VIO displacement and solves the linearized solutions until convergence. The loose coupling algorithm uses the GPS fix as an initiation position, linearizing and solving using the base station equations only. The tight coupling algorithm linearizes both the base station and GPS position equations, using an arbitrary initial position. To account for multipath effects, the linearization and solution are performed for multiple random sets of measurements and the position with the smallest error metric is selected.