Training sequence for a radio communications system

• US 20020122498A1
• Filed: 02/19/2002
• Published: 09/05/2002
• Est. Priority Date: 11/30/2000
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Mithat C. Dogan
• Inventors: Dogan, Mithat C.
• Granted Patent: US 6,731,689 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04L 7/046 using a dotting sequence

Abstract

A training sequence for a radio communications system is provided. According to one aspect of the present invention, the invention includes a core sequence of symbols, a successive repetition of the core sequence, and a marker sequence having a sequence of symbols different from the core sequence.

Claims

1. A training sequence for a radio communications system comprising:

a core sequence of symbols;

a successive repetition of the core sequence; and

a marker sequence having sequence of symbols different from the core sequence.

2. The training sequence of claim 1 wherein the core sequence is transmitted as binary symbols and the marker sequence is equal and opposite in sign to the core sequence.

3. The training sequence of claim 1 wherein the core sequence augmented with the marker sequence forms a vector that is orthogonal to a vector formed by the core sequence augmented with the core sequence.

4. The training sequence of claim 1 wherein the marker sequence follows the repetition of the core sequence.

5. The training sequence of claim 1 wherein the marker sequence precedes the repetition of the core sequence.

6. The training sequence of claim 1 wherein the repetition of the core sequence has a duration longer than the maximum round trip delay time from a terminal transmitting the training sequence to a terminal receiving the training sequence and back.

7. The training sequence of claim 1 wherein the repetition of the core sequence has a duration longer than a duration of a beam forming analysis window plus the maximum round trip delay time from a terminal transmitting the training sequence to a terminal receiving the training sequence and back.

8. The training sequence of claim 1 wherein the repetition of the core sequence has a duration longer than the maximum round trip delay time from a terminal transmitting the training sequence to a terminal receiving the training sequence and back plus a random delay applied by the terminal transmitting the training sequence.

9. The training sequence of claim 1 wherein the repetition of the core sequence comprises a repetition of the core sequence successively a specified number of times.

10. The training sequence of claim 1 wherein the core sequence consists essentially of 12 symbols.

11. The training sequence of claim 1 wherein the core sequence has a normalized cross-correlation of about ⅓

.

12. The training sequence of claim 1 wherein the core sequence has a normalized autocorrelation of about ⅓

.

13. The training sequence of claim 1 wherein the absolute value of the mean of th e core sequence is about zero.

15. The method of claim 14 wherein transmitting the training sequence comprises transmitting binary symbols and wherein generating the marker sequence comprises generating a marker sequence that is equal and opposite in sign to the core sequence.

16. The method of claim 14 wherein the core sequence augmented with the marker sequence forms a vector that is orthogonal to a vector formed by the core sequence augmented with the core sequence.

17. The method of claim 14 wherein the repetition of the core sequence has a duration longer than the maximum round trip delay time from a terminal transmitting the training sequence to a terminal receiving the training sequence and back.

18. The method of claim 14 wherein the core sequence has a normalized cross-correlation of about ⅓

.

19. The method of claim 14 wherein the core sequence has a normalized autocorrelation of about ⅓

.

20. The method of claim 14 wherein the absolute value of the mean of the core sequence is about zero.

14. A method comprising:

generating a core sequence of symbols;

generating a successive repetition of the core sequence; and

generating a marker sequence having sequence of symbols different from the core sequence;

combining the repetition of the core sequence and marker sequence to form a training sequence; and

transmitting the training sequence with a communications burst in a radio communications system.

21. A machine-readable medium having stored thereon data representing sequences of instructions which, when executed by a machine, cause the machine to perform operations comprising:

generating a core sequence of symbols;

generating a successive repetition of the core sequence; and

generating a marker sequence having sequence of symbols different from the core sequence;

combining the repetition of the core sequence and marker sequence to form a training sequence; and

transmitting the training sequence with a communications burst in a radio communications system.

22. The medium of claim 21 wherein transmitting the training sequence comprises transmitting binary symbols and wherein generating the marker sequence comprises generating a marker sequence that is equal and opposite in sign to the core sequence.

23. The medium of claim 21 wherein the core sequence augmented with the marker sequence forms a vector that is orthogonal to a vector formed by the core sequence augmented with the core sequence.

24. The medium of claim 21 wherein the repetition of the core sequence has a duration longer than the maximum round trip delay time from a terminal transmitting the training sequence to a terminal receiving the training sequence and back.

25. The medium of claim 21 wherein the core sequence has a normalized cross-correlation of about ⅓

.

26. The medium of claim 21 wherein the core sequence has a normalized autocorrelation of about ⅓

.

27. The medium of claim 21 wherein the absolute value of the mean of the core sequence is about zero.