Positioning system using ultrasonic waves and method for operating the same

A system of determining a position of a mobile device, comprising:

• a synchronizer configured to transmit a synchronization signal;
• a plurality of ultrasonic signal transmitters, each of which is configured to transmit an ultrasonic signal at a predetermined time;
• and
• a mobile device configured to receive the synchronization signal and ultrasonic signals from at least part of the plurality of ultrasonic signal transmitters, wherein the mobile device is configured to determine the mobile device's position using information available thereto,
• wherein the predetermined time of each ultrasonic signal transmitter has a time interval from receipt of the synchronization signal from a source thereof.

A method of determining a position of a mobile device, the method comprising:

• receiving, by a mobile device, a synchronization signal;
• synchronizing the mobile device using the synchronization signal;
• receiving, by the mobile device at a receipt time, an first ultrasonic signal transmitted from a first source located at a source location at a first transmission time, which is after a first predetermined interval from the first source's receipt of the synchronization signal;
• and
• computing a first distance between the mobile device and the first source location using the first predetermined interval and further using a first time difference between receipt of the first ultrasonic signal and receipt of the synchronization signal by the mobile device;
• receiving, by the mobile device, a second ultrasonic signal transmitted from a second source located at a second source location at a second transmission time, which is after a second predetermined interval from the second source's receipt of the synchronization signal;
• and
• computing a second distance between the mobile device and the second source location using the second predetermined interval and further using a second time difference between receipt of the second ultrasonic signal and receipt of the synchronization signal by the mobile device;
• and
• determining the mobile device's position using the first distance and the second distance.