US Patent 12092728 Positioning device, communications system and method

An exemplary communications system includes a first base station and a second base station. The first base station transmits a first signal to the second base station, and the second base station receives the first signal and transmits a second signal in response. The first base station receives the second signal and transmits a third signal in response. A receiving unit of a device receives the first, second, and third signals. The device measures a first delay time between receipt of the first signal and receipt of the second signal, and measures a first round trip time based on receipt of the second signal and the third signal. A second round trip time and a second delay time are determined and a first time difference of arrival is calculated based on the first round trip time, first delay time, second round trip time and second delay time.