US Patent 10271301 Systems and methods for tracking items

An example system includes a first beacon configured to communicate a first wireless signal. A first hub is in communication with the first beacon. The first hub is configured to detect a first signal strength of the first wireless signal. The example system further includes a second hub in communication with the first beacon. The second hub is configured to detect a second signal strength of the first wireless signal. The example system further includes a computing system in communication with the first hub and the second hub. The computing system includes a noise filter and a beacon assignor. The noise filter includes a quadratic estimator configured to output a first estimated distance between the first beacon and the first hub, output a second estimated distance between the first beacon and the second hub, and disregard a third estimated distance between the first beacon and the first hub if the third estimated distance is derived from a ghost signal. The beacon assignor is configured to assign the first beacon to the first hub if the first estimated distance is less than the second estimated distance.