Method for asynchronous transmission of communication data between periodically blanked terminals

• US 7,978,610 B1
• Filed: 01/24/2008
• Issued: 07/12/2011
• Est. Priority Date: 01/24/2008
• Status: Active Grant

• Current Assignee: L3 Technologies, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Carver, John J. II, McIntire, William K., Thomson, Larry S.
• Primary Examiner(s): Rao; Seema S.
• Assistant Examiner(s): DUONG, CHRISTINE T
• Application Number:
  US12/019,471
• Time in Patent Office: 1,265 Days
• Field of Search: None
• US Class Current: 370/236.2
• CPC Class Codes: H04W 56/0065 using measurement of signal travel time

Abstract

A method for asynchronous transmission of communication data between periodically blanked terminals separated by an unknown distance is disclosed. A bursted signal is transmitted from a first terminal with a burst time t_B and a burst cycle period T. The bursted signal is received at a second terminal. A bursted response signal is transmitted from the second terminal to the first terminal. The bursted response signal has a burst cycle period of T/2 and includes a pair of response bursts, with each burst in the pair having a burst time t_A≦T/2−t_B. Each burst in the pair of response bursts carries an identical data payload. At least one of the response bursts is received at the first terminal.

Claims

1. A method for asynchronous transmission of communication data between periodically blanked terminals separated by an unknown distance, comprising:

transmitting a bursted signal from a first periodically blanked terminal with a burst time t_B and a burst cycle period T;

receiving the bursted signal at a second periodically blanked terminal;

transmitting a bursted response signal from the second periodically blanked terminal to the first periodically blanked terminal, wherein the bursted response signal has a burst cycle period of T/2 and includes a pair of response bursts, with each burst in the pair of response bursts having a burst time t_A≦

T/2−

t_B and wherein each burst in the pair of response bursts contains an identical data payload.

2. A method as in claim 1, wherein transmitting the bursted response signal from the second periodically blanked terminal further comprises transmitting the bursted response signal having a duty cycle and the burst cycle period that is previously known at the second periodically blanked terminal.

3. A method as in claim 1, wherein transmitting the bursted response signal from second periodically blanked terminal to the first periodically blanked terminal further comprises transmitting the bursted response signal having a duty cycle that is previously known at the first periodically blanked terminal.

4. A method as in claim 1, wherein transmitting the bursted signal further comprises transmitting the bursted signal having a transmit data payload.

5. A method as in claim 4, wherein transmitting the bursted signal further comprises transmitting the bursted signal having the transmit data payload, wherein the transmit data payload includes a range bit configured to enable a distance between the first periodically blanked terminal and the second periodically blanked terminal to be determined.

6. A method as in claim 4, wherein transmitting the bursted signal further comprises transmitting the bursted signal having the transmit data payload, wherein the transmit data payload includes information specifying a burst cycle period and a duty cycle of the bursted signal.

7. A method as in claim 1, further comprising determining at the second periodically blanked terminal a burst cycle period and a duty cycle of the bursted signal.

8. A method as in claim 5, wherein transmitting the bursted response signal further comprises transmitting the bursted response signal including a plurality of pairs of response bursts, wherein each burst in the pair of response bursts contains the identical data payload, wherein the identical data payload of each of the plurality of pairs of response bursts includes a range bit received on the bursted signal that is transmitted back to the first periodically blanked terminal.

9. A method as in claim 1, wherein transmitting the bursted response signal further comprises transmitting the bursted response signal including the pair of response bursts, wherein each burst in the pair of response bursts includes information configured to identify one of a first burst and a second burst in the pair of response bursts to determine which of the first burst and the second burst was received at the first periodically blanked terminal.

10. A method as in claim 9, wherein the information comprises a range bit that is included in the first burst and the second burst in the pair of response bursts, wherein the range bit is inverted in one of the first and the second bursts to identify which of the first and second bursts in the pair of response bursts is received at the first periodically blanked terminal.

11. A method as in claim 1, further comprising setting the burst time t_B of the first periodically blanked terminal at 25 percent duty cycles.

12. A method as in claim 1, further comprising transmitting the bursted response signal from the second periodically blanked terminal after receiving the bursted signal from the first periodically blanked terminal, wherein a guard period is provided between bursts on the bursted signal and bursts on the bursted response signal.

13. A method as in claim 12, further comprising providing the guard period between bursts on the bursted signal and bursts on the bursted response signal at the second periodically blanked terminal, wherein the guard period has a length between 2 nanoseconds and 100 milliseconds.

14. A method as in claim 12, further comprising providing the guard period between the bursts on the bursted signal and the bursts on the bursted response signal at the second periodically blanked terminal, wherein the guard period is provided by reducing the burst time t_A of the bursts at the second periodically blanked terminal without changing the burst cycle period.

15. A method as in claim 1, wherein transmitting the bursted signal further comprises transmitting the bursted signal from the first periodically blanked terminal with the burst time t_B, wherein the burst time has a length between 5 nanoseconds and 100 milliseconds.

16. A method as in claim 1, wherein transmitting the bursted signal further comprises transmitting the bursted signal from the first periodically blanked terminal with the burst cycle period T, wherein the burst cycle period has a length between 10 nanoseconds and 200 milliseconds.

17. A system for asynchronous transmission of communication data between periodically blanked terminals separated by an unknown distance, comprising

a first periodically blanked terminal configured to transmit a bursted signal with a burst time t_B and a burst cycle period T;

a second periodically blanked terminal configured to receive the bursted signal from the first periodically blanked terminal; and

the second periodically blanked terminal configured to transmit a bursted response signal to the first periodically blanked terminal, wherein the bursted response signal has a burst cycle period of T/2 and includes a pair of response bursts, with each burst in the pair of response bursts having a burst time t_A≦

T/2−

t_B and wherein each burst in the pair of response bursts contains an identical data payload to enable the first periodically blanked terminal to receive the data payload on at least one of the bursts in the pair of response bursts.

18. A system as in claim 17, wherein at least one burst in the bursted signal transmitted by the first periodically blanked terminal further comprises a transmit data payload including a range bit.

19. A system as in claim 18, wherein the identical data payload carried by the pair of response bursts in the bursted response signal includes a copy of the range bit received in the bursted signal from the first periodically blanked terminal.

20. A system as in claim 17, wherein each burst in the pair of response bursts further includes a unique identifier to enable at least one of a first burst and a second burst in the pair of response bursts to be identified at the first periodically blanked terminal.

21. A system as in claim 17, wherein the second periodically blanked terminal is further configured to add a guard period between bursts on the bursted signal received from the first periodically blanked terminal and the bursts on the bursted response signal generated at the second periodically blanked terminal, wherein the guard period is provided by reducing the burst time t_A of the bursts at the second periodically blanked terminal without changing the burst cycle period.

22. A system as in claim 17, wherein the first and second periodically blanked terminals include modems capable of controlling timing of transmit periods in RF hardware coupled to each periodically blanked terminal to enable micro time-domain-duplex communications between the first and second periodically blanked terminals.

23. A system for asynchronous transmission of communication data between periodically blanked terminals separated by an unknown distance, comprising:

a transmitting means for emitting a bursted signal from a first periodically blanked terminal with a burst time t_B and a burst cycle period T;

a receiving means for detecting the bursted signal at a second periodically blanked terminal; and

a transmitting means for transmitting a bursted response signal from the second periodically blanked terminal to the first periodically blanked terminal, wherein the bursted response signal has a burst cycle period of T/2 and includes a pair of response bursts, with each burst in the pair of response bursts having a burst time t_A≦

T/2−

t_B and wherein each burst in the pair of response bursts contains an identical data payload.