Method and system to providing fast access channel

• US 7,778,149 B1
• Filed: 07/27/2006
• Issued: 08/17/2010
• Est. Priority Date: 07/27/2006
• Status: Active Grant

• Current Assignee: Tadaaki Chigusa
• Original Assignee: Tadaaki Chigusa
• Inventors: Kaiser, Daryl, McGrath, Stephen, Sayers, Ian
• Primary Examiner(s): Trost, IV; William
• Assistant Examiner(s): Kasparek; Kyle C
• Application Number:
  US11/494,410
• Time in Patent Office: 1,482 Days
• Field of Search: 370/208, 370/203, 375/260
• US Class Current: 370/208
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements

Abstract

A system for providing a fast access channel is disclosed. The system includes a transmitter configured to transmit a first long contention symbol and one or more subsequent long contention symbols. The first long contention symbol is followed by the subsequent long contention symbols. The system further includes a receiver configured to receive the first and subsequent long contention symbols and determine a contention code and a contention channel transmitted with the contention code based on the first and subsequent long contention symbols. Each of the first and subsequent long contention symbols includes a long cyclic prefix and a number of identical contention symbols.

Claims

1. A system for providing a fast access channel, comprising:

a transmitter configured to transmit a first long contention symbol and a second long contention symbol, the first long contention symbol being followed by the second long contention symbol; and

a receiver configured to receive the first and second long contention symbols and determine a contention code and a contention channel transmitted with the contention code based on the first and second long contention symbols;

wherein each of the first and second long contention symbols includes a long cyclic prefix and a plurality of contention symbols;

wherein the plurality of contention symbols in the first long contention symbol are identical; and

wherein the plurality of contention symbols in the second long contention symbol are identical.

2. The system of claim 1 wherein the plurality of contention symbols in each of the first and second long contention symbols include at least three contention symbols.

3. The system of claim 1 wherein the plurality of contention symbols in each of the first and second long contention symbols are constructed based on a 802.16a standard.

4. The system of claim 1 wherein a length of the long cyclic prefix of each of the first and second long contention symbols is an integer multiple times a length of a normal cyclic prefix based on a 802.16a standard.

5. The system of claim 1 wherein a length of the long cyclic prefix of each of the first and second long contention symbols equals a length of a normal cyclic prefix based on a 802.16a standard multiplied by a total number of contention symbols included in each of the plurality of contention symbols.

6. The system of claim 1 wherein the first long contention symbol includes a calibration contention code and the second long contention symbol includes a selected contention code.

7. The system of claim 1 wherein the receiver is further configured to measure a phase difference of the contention channel on a per subcarrier basis between the first and second long contention symbols and determine the contention code.

8. The system of claim 1 wherein the transmitter is further configured to transmit one or more additional long contention symbols;

and

wherein the receiver is further configured to receive the one or more additional long contention symbols and determine respective contention codes and contention channels transmitted with the respective contention codes based on the first long contention symbol, wherein the first long contention symbol includes a calibration contention code.

9. A system for providing a fast access channel, comprising:

a receiver configured to;

receive first and second long contention symbols, wherein the first long contention symbol is followed by the second long contention symbol, and each of the first and second long contention symbols includes a long cyclic prefix and a plurality of identical contention symbols;

retrieve information relating to a selected contention channel from the first and second long contention symbols;

remove phase ramp and phase offset information from the retrieved information to generate refined information relating to the selected contention channel;

perform correlation coefficient computations between the refined information relating to the selected contention channel and a plurality of contention codes; and

determine a contention code from the plurality of contention codes based on results of the correlation coefficient computations.

10. The system of claim 9 wherein the receiver is further configured to:

compute a power level of the selected contention channel;

compare the power level against a threshold value resulting in a comparison; and

utilize the comparison to assist in determining the contention code.

11. The system of claim 9 wherein the receiver is further configured to use Fast Hadamard Transform to perform the correlation coefficient computations.

12. The system of claim 10 wherein the plurality of identical contention symbols in each of the first and second long contention symbols include at least three contention symbols.

13. The system of claim 9 wherein the plurality of identical contention symbols in each of the first and second long contention symbols are constructed based on a 802.16a standard.

14. The system of claim 9 wherein a length of the long cyclic prefix of each of the first and second long contention symbols is an integer multiple times a length of a normal cyclic prefix based on a 802.16a standard.

15. The system of claim 9 wherein a length of the long cyclic prefix of each of the first and second long contention symbols equals a length of a normal cyclic prefix based on a 802.16a standard multiplied by a total number of contention symbols included in each of the plurality of contention symbols.

16. The system of claim 9 wherein the first long contention symbol includes a calibration contention code and the second long contention symbol includes a selected contention code.

17. A method for providing a fast access channel, the method comprising:

receiving a first long contention symbol, wherein the first long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols;

receiving a second long contention symbol, wherein the second long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols; and

determining a contention code and a contention channel on which the contention code was transmitted based on the first and second long contention symbols;

wherein the first long contention symbol is followed by the second long contention symbol.

18. The method of claim 17 wherein the plurality of identical contention symbols in each of the first and second long contention symbols are constructed based on a 802.16a standard.

19. The method of claim 17 wherein a length of the long cyclic prefix of each of the first and second long contention symbols equals a length of a normal cyclic prefix based on a 802.16a standard multiplied by a total number of contention symbols included in each of the plurality of contention symbols.

20. The method of claim 17 wherein the first long contention symbol includes a calibration contention code and the second long contention symbol includes a selected contention code.

21. A device for operating on a fast access channel, comprising a receiver configured to:

receive a first long contention symbol, wherein the first long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols;

receive a second long contention symbol, wherein the second long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols; and

determine a contention code and a contention channel on which the contention code was transmitted based on the first and second long contention symbols;

wherein the first long contention symbol is followed by the second long contention symbol.

22. The method of claim 21 wherein the plurality of identical contention symbols in each of the first and second long contention symbols are constructed based on a 802.16a standard.

23. The method of claim 21 wherein a length of the long cyclic prefix of each of the first and second long contention symbols equals a length of a normal cyclic prefix based on a 802.16a standard multiplied by a total number of contention symbols included in each of the plurality of contention symbols.

24. The method of claim 21 wherein the first long contention symbol includes a calibration contention code and the second long contention symbol includes a selected contention code.

25. A device for operating on a fast access channel, comprising a transmitter configured to:

transmit a first long contention symbol, wherein the first long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols; and

transmit a second long contention symbol, wherein the second long contention symbol includes a long cyclic prefix and a plurality of identical contention symbols;

wherein the first and second long contention symbols are for a receiver to determine a contention code and a contention channel on which the contention code was transmitted based on the first and second long contention symbols; and

wherein the first long contention symbol is followed by the second long contention symbol.

26. The method of claim 25 wherein the plurality of identical contention symbols in each of the first and second long contention symbols are constructed based on a 802.16a standard.

27. The method of claim 25 wherein a length of the long cyclic prefix of each of the first and second long contention symbols equals a length of a normal cyclic prefix based on a 802.16a standard multiplied by a total number of contention symbols included in each of the plurality of contention symbols.

28. The method of claim 25 wherein the first long contention symbol includes a calibration contention code and the second long contention symbol includes a selected contention code.

29. A system for providing a fast access channel using a contention symbol comprising a plurality of contention channels, wherein at least one of the plurality of contention channels is assigned to one of a plurality of transmitters, and wherein each of the plurality of contention channels is configured to carry a contention code selected from a plurality of contention codes, the system comprising a receiver configured to:

receive a first long contention symbol and a second long contention symbol, each including a long cyclic prefix and a plurality of identical contention symbols;

determine which contention channel of the plurality of contention channels is carrying a contention code based on at least one of the first and second long contention symbols;

determine the contention code based on the determined contention channel and the first and second long contention symbols, wherein the determined contention code comprises variable information; and

determine a transmitter that transmitted the determined contention code based on the determined contention channel.

30. The system of claim 29 wherein each of plurality of contention channels comprises a subset of a plurality of subcarriers.

31. The system of claim 29 wherein at least one of the plurality of contention channels is assigned to a second one of the plurality of transmitters, wherein the receiver is further configured to:

determine which second contention channel of the plurality of contention channels is carrying a second contention code based on at least one of the first and second long contention symbols;

determine the second contention code based on the determined second contention channel and the first and second long contention symbols, wherein the determined second contention code comprises variable information; and

determine a second transmitter that transmitted the determined second contention code based on the determined second contention channel.

32. The system of claim 29 wherein at least two of the plurality of contention channels are assigned to the transmitter, wherein the receiver is further configured to:

determine which second contention channel of the plurality of contention channels is carrying a second contention code based on at least one of the first and second long contention symbols; and

determine the second contention code based on the determined second contention channel and the first and second long contention symbols, wherein the determined second contention code comprises variable information.