Method and system for coordinating timing among ultrawideband transmissions

• US 6,492,904 B2
• Filed: 12/08/1999
• Issued: 12/10/2002
• Est. Priority Date: 09/27/1999
• Status: Expired due to Fees

• Current Assignee: Alereon Incorporated (PNG Telecommunications, Inc.)
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Richards, James L.
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US09/456,410
• Publication Number:
  US 20020000916A1
• Time in Patent Office: 1,098 Days
• Field of Search: 340/568.1, 340/568.5, 340/568.6, 340/571, 340/572.1, 340/572.4, 340/573.4, 340/573.7, 340/573.1, 340/573.3, 340/10.4, 340/10.41, 340/991, 340/992, 340/826.41, 340/826.49, 340/826.54, 340/539, 342/28, 342/33, 375/200, 375/295
• US Class Current: 340/539.1
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/02216 Timing or synchronisation of the receivers
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10306 ultra wide band
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: H04B 1/7163 using impulse radio
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04B 1/719 Interference-related aspects
• CPC Class Codes: H04B 2001/6908 using time hopping

Abstract

An asset, object, person or animal monitoring system and associated method for monitoring assets, objects, people or animals utilizing impulse radio techniques. The asset, object, person or animal monitoring system of the present invention can vary the duty cycles of the impulse radio transmitters, by both manual and automatic means, to adapt to varied requirements.

Claims

1. A method of impulse radio duty cycle variation and synchronization for an impulse radio system, comprising:

synchronizing an internal clock means associated with a carrier wave-less impulse radio transmitter to a timing means;

synchronizing an internal clock means associated with a carrier wave-less impulse radio receiver to a timing means corresponding to said timing means used to synchronize said carrier wave-less impulse radio transmitter;

transmitting carrier wave-less impulse radio transmissions at predetermined times, each of said carrier wave-less impulse radio transmissions including a train of time-spaced pulses and said predetermined transmission times being determined by said internal clock associated with said carrier wave-less impulse radio transmitter; and

listening by said carrier wave-less impulse radio receiver for said carrier wave-less impulse radio transmissions at predetermined intervals surrounding said predetermined transmission times of said carrier wave-less impulse radio transmitter, said listening step further includes

locking onto one of said carrier wave-less impulse radio transmissions during each of said predetermined intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

2. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 1, wherein said timing means is an clock means synchronized with Universal Time Code time.

3. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 1, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an infrared current time transfer.

4. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 1, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an optical current time transfer.

5. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 1, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an RF wireless current time transfer.

6. A method of impulse radio duty cycle variation and synchronization for an impulse radio system including at least two carrier wave-less impulse radio transmitters, comprising:

receiving, at a carrier wave-less impulse radio receiver, a carrier wave-less impulse radio transmission including a train of time-spaced pulses, said carrier wave-less impulse radio transmission containing information about which carrier wave-less impulse radio transmitter is transmitting and said carrier wave-less impulse radio receiver is programmed to know a duty cycle of that carrier wave-less impulse radio transmitter; and

listening for subsequent carrier wave-less impulse radio transmissions, each of which include a train of time-spaced pulses, from that carrier wave-less impulse radio transmitter according to predetermined transmission intervals associated with the duty cycle of that carrier wave-less impulse radio transmitter, said listening step further includes;

locking onto one of said carrier wave-less impulse radio transmissions during each of said predetermined transmission intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

7. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 6, further comprising monitoring for additional carrier wave-less impulse radio transmissions from distinct carrier wave-less impulse radio transmitters for a predetermined time.

8. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 6, further comprising enabling said carrier wave-less impulse radio receiver to be active only during the predetermined transmission intervals of the at least two carrier wave-less impulse radio transmitters.

9. A method of impulse radio duty cycle variation and synchronization for an impulse radio system, comprising:

transmitting, from a carrier wave-less impulse radio transmitter, carrier wave-less impulse radio transmissions, each of which include a train of time-spaced pulses, at least once during a predetermined transmission time interval; and

listening, at a carrier wave-less impulse radio receiver, for impulse carrier wave-less radio transmissions at least during a time interval corresponding to the carrier wave-less impulse radio predetermined transmission time interval, said listening step further includes;

locking onto one of said carrier wave-less impulse radio transmissions during each of said time intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

10. The method of impulse radio duty cycle variation and synchronization for an impulse radio system of claim 9, wherein said time interval is increased by anticipated inaccuracies due to clock drift or timing inaccuracies of the carrier wave-less impulse radio transmitter.

11. A system, comprising:

an internal clock synchronizing means associated with a carrier wave-less impulse radio transmitter, said internal clock synchronizing means synchronizing said carrier wave-less impulse radio transmitter to a timing means, said impulse radio carrier wave-less transmitter transmits carrier wave-less impulse radio transmissions at predetermined transmission times, each of said carrier wave-less impulse radio transmissions including a train of time-spaced pulses and said predetermined transmission times being determined by said internal clock associated with said carrier wave-less impulse radio transmitter; and

an internal clock synchronizing means associated with a carrier wave-less impulse radio receiver, said internal clock synchronizing means synchronizing said carrier wave-less impulse radio receiver to a timing means corresponding to said timing means used to synchronize said carrier wave-less impulse radio transmitter, said carrier wave-less impulse radio receiver listens for said carrier wave-less impulse radio transmissions at predetermined intervals surrounding said predetermined transmission times of said carrier wave-less impulse radio transmitter and said carrier wave-less impulse radio receiver locks onto one of said carrier wave-less impulse radio transmissions during each of said predetermined intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

12. The system of claim 11, wherein said timing means is an clock means synchronized with Universal Time Code time.

13. The system of claim 11, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an infrared current time transfer.

14. The system of claim 11, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an optical current time transfer.

15. The system of claim 11, wherein said synchronizing of said internal clock means associated with a carrier wave-less impulse radio transmitter and carrier wave-less impulse radio receiver to a timing means is accomplished by an RF wireless current time transfer.

16. A system, comprising:

a carrier wave-less impulse radio transmitter, said carrier wave-less radio transmitter transmits carrier wave-less impulse radio transmissions, each of which include a train of time-spaced pulses, at least once during a predetermined interval;

a carrier wave-less impulse radio receiver, said carrier wave-less impulse radio receiver listens for carrier wave-less impulse radio transmissions at least during an interval corresponding to the carrier wave-less impulse radio transmission predetermined interval; and

said carrier wave-less impulse radio receiver locks onto one of said carrier wave-less impulse radio transmissions during each of said intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

17. The system of claim 16, wherein said interval is increased by anticipated inaccuracies due to clock drift or timing inaccuracies of the carrier wave-less impulse radio transmitter.

18. A system, comprising:

at least two carrier wave-less impulse radio transmitters;

a carrier wave-less impulse radio receiver capable of receiving a carrier wave-less impulse radio transmission including a train of time-spaced pulses that contain information about which carrier wave-less impulse radio transmitter is transmitting and said carrier wave-less impulse radio receiver is programmed to know a duty cycle of that carrier wave-less impulse radio transmitter;

said carrier wave-less impulse radio receiver capable of listening for subsequent carrier wave-less impulse radio transmissions, each of which include a train of time-spaced pulses, from that carrier wave-less impulse radio transmitter according to predetermined transmission intervals associated with the duty cycle of that carrier wave-less impulse radio transmitter; and

said carrier wave-less impulse radio receiver locks onto one of said carrier wave-less impulse radio transmissions during each of said predetermined transmission intervals by adjusting the timing of a train of template signal pulses generated by the carrier wave-less impulse radio receiver such that said timing of the train of template signal pulses is substantially coincident with the timing of the train of time-spaced pulses of the received carrier wave-less impulse radio transmission.

19. The system of claim 18, wherein said carrier wave-less impulse radio receiver is capable of monitoring for additional carrier wave-less impulse radio transmissions from distinct carrier wave-less impulse radio transmitters for a predetermined time.

20. The system of claim 18, wherein said carrier wave-less impulse radio receiver is active only during the predetermined transmission intervals of the at least two carrier wave-less impulse radio transmitters.