System and method for position determination by impulse radio

• US 20020109632A1
• Filed: 09/18/2001
• Published: 08/15/2002
• Est. Priority Date: 03/23/1998
• Status: Active Grant

• Current Assignee: Humatics Corporation
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Richards, James L., Fullerton, Larry W., Cowie, Ivan A.
• Granted Patent: US 6,611,234 B2
• Time in Patent Office: Days
• US Class Current: 342/458
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/76 wherein pulse-type signals are transmitted
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

A system and a method for position determination by impulse radio using a first transceiver having a first clock providing a first reference signal and a second transceiver placed spaced from the first transceiver. The system determines the position of the second transceiver. The second transceiver has a second clock that provides a second reference signal. A first sequence of pulses are transmitted from the first transceiver. The first sequence of pulses are then received at the second transceiver and the second transceiver is then synchronized with the first sequence of pulses. A second sequence of pulses are transmitted from the second transceiver. The first transceiver receives the second sequence of pulses and the first transceiver is synchronized with the second sequence of pulses. A delayed first reference signal is generated in response to the synchronization with the second sequence of pulses. A time difference between the delayed first reference signal and the first reference signal is then measured. The time difference indicates a total time of flight of the first and second sequence of pulses. The distance between the first and the second transceiver is determined from the time difference. The direction of the second transceiver from the first transceiver is determined using a directional antenna. Finally, the position of the second transceiver is determined using the distance and the direction.

Claims

1. In an impulse radio system having a first transceiver with a first clock providing a first reference signal and a second transceiver spaced from said first transceiver and having a second clock providing a second reference signal, a method for determining the position of the second transceiver comprising the steps of:

transmitting from said first transceiver a first sequence of pulses;

receiving said first sequence of pulses at said second transceiver;

synchronizing said second transceiver with said first sequence of pulses;

transmitting from said second transceiver a second sequence of pulses;

receiving at said first transceiver said second sequence of pulses;

synchronizing said first transceiver with said second sequence of pulses;

generating a delayed first reference signal in response to said synchronization with said second sequence of pulses; and

measuring a time difference between said delayed first reference signal and said first reference signal, said time difference indicating a total time of flight of said first and second sequence of pulses.