Preamble structure and acquisition for a wireless communication system

• US 8,929,353 B2
• Filed: 05/09/2007
• Issued: 01/06/2015
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Michael Mao
• Primary Examiner(s): TAYLOR, NATHAN SCOTT
• Application Number:
  US11/746,111
• Publication Number:
  US 20080279220A1
• Time in Patent Office: 2,799 Days
• Field of Search: 370/347, 370/500, 370/208, 370/294, 370/491, 375/343, 375/141, 375/260, 455/450
• US Class Current: 370/347
• CPC Class Codes: H04J 3/02 Details electronic switching or gating H03K17/00
• CPC Class Codes: H04L 2027/0034 using hypothesis testing
• CPC Class Codes: H04L 2027/0095 in a preamble or similar structure
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657
• CPC Class Codes: H04L 27/2604 Multiresolution systems by means of multiresolution subcarriers H04L27/183, H04L27/3488
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2662 Symbol synchronisation
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

Techniques for sending sector/system information in TDM pilots using a hierarchical pilot structure are described. A base station sends multiple sets of bits for the sector/system information in multiple TDM pilots. The set of bits sent in a given TDM pilot may include bits sent in earlier TDM pilots. In one design, the base station generates a first TDM pilot based on a first set of bits, generates a second TDM pilot based on a second set of bits that includes the first set, generates a third TDM pilot based on all bits for the information, and sends the TDM pilots. A terminal performs detection to obtain a first detected value for the first TDM pilot, performs detection based on the first detected value to obtain a second detected value for the second TDM pilot, and performs detection based on the first and second detected values to obtain a third detected value for the third TDM pilot.

Claims

1. An apparatus comprising:

at least one processor configured to;

generate a first pilot sequence based on a first set of bits of information to send,

generate a second pilot sequence based on a second set of bits of the information, the second set of bits being different from the first set of bits, the second pilot sequence being different from the first pilot sequence,

generate a third pilot sequence based on all bits of the information, the third pilot sequence being different from the first pilot sequence and also different from the second pilot sequence,

generate a first pilot based on the first pilot sequence,

generate a second pilot based on the second pilot sequence,

generate a third pilot based on the third pilot sequence, and

send the first, second, and third pilots in first, second, and third time intervals, respectively,

wherein the first and second pilot sequences are generated based on non-overlapping sets of bits of the information.

2. The apparatus of claim 1, wherein the first set includes Ml bits of the information, and wherein the second set includes the Ml bits in the first set and M2 additional bits of the information, where M1 and M2 are integer values.

3. The apparatus of claim 1, wherein the second set comprises all bits of the information.

4. The apparatus of claim 1, wherein the information comprises 12 bits, the first set comprises 2 bits, and the second set comprises 8 bits and includes the 2 bits in the first set.

5. The apparatus of claim 1, wherein the at least one processor is configured to generate a pseudo-random number (PN) sequence for each pilot based on the set of bits of the information to send in the pilot, and to generate each pilot based on the PN sequence for the pilot, and wherein the pilot sequence for each pilot comprises the PN sequence for the pilot.

6. The apparatus of claim 1, wherein for each pilot, the at least one processor is configured to generate a pseudo-random number (PN) sequence based on the set of bits to send in the pilot, to generate pilot symbols based on the PN sequence, to map the pilot symbols to subcarriers used for the pilot, and to transform the mapped pilot symbols to obtain a sequence of samples for the pilot.

7. The apparatus of claim 1, wherein the first pilot is adjacent to the second pilot in time.

8. The apparatus of claim 1, wherein the first, second and third pilots are time division multiplexed (TDM).

9. The apparatus of claim 1, wherein the information to send comprises sector-specific information, or system information, or both.

10. The apparatus of claim 1, wherein the information to send in the first, second, and third pilots comprises a sector identifier (ID).

11. The apparatus of claim 1, wherein the first set of bits and the second set of bits comprise a sector identifier (ID).

12. The apparatus of claim 1, wherein the third pilot is sent on subcarriers evenly spaced across system bandwidth.

13. The apparatus of claim 1, wherein the first, second, and third pilots are sent in different symbol periods of a frame of a predetermined time duration.

14. A method comprising:

generating a first pilot sequence based on a first set of bits of information to send;

generating a second pilot sequence based on a second set of bits of the information, the second set of bits being different from the first set of bits, the second pilot sequence being different from the first pilot sequence;

generating a third pilot sequence based on all bits of the information, the third pilot sequence being different from the first pilot sequence and also different from the second pilot sequence;

generating a first pilot based on the first pilot sequence;

generating a second pilot based on the second pilot sequence;

generating a third pilot based on the third pilot sequence; and

sending the first, second, and third pilots in first, second, and third time intervals, respectively,

wherein the first and second pilot sequences are generated based on non-overlapping sets of bits of the information.

15. The method of claim 14, further comprising:

generating a pseudo-random number (PN) sequence for each pilot based on the set of bits of the information to send in the pilot, wherein the pilot sequence for each pilot comprises the PN sequence for the pilot, and

generating each pilot based on the PN sequence for the pilot.

16. The method of claim 14, wherein the information to send in the first, second, and third pilots comprises a sector identifier (ID).

17. The method of claim 14, wherein the first set of bits and the second set of bits comprise a sector identifier (ID).

18. The method of claim 16, wherein the third pilot is sent on subcarriers evenly spaced across system bandwidth.

19. The method of claim 16, wherein the first, second, and third pilots are sent in different symbol periods of a frame of a predetermined time duration.

20. An apparatus comprising:

means for generating a first pilot sequence based on a first set of bits of information to send;

means for generating a second pilot sequence based on a second set of bits of the information, the second set of bits being different from the first set of bits, the second pilot sequence being different from the first pilot sequence;

means for generating a third pilot sequence based on all bits of the information, the third pilot sequence being different from the first pilot sequence and also different from the second pilot sequence;

means for generating a first pilot based on the first pilot sequence;

means for generating a second pilot based on the second pilot sequence;

wherein the first and second pilot sequences are generated based on non-overlapping sets of bits of the information;

means for generating a third pilot based on the third pilot sequence; and

means for sending the first, second, and third pilots in first, second, and third time intervals, respectively.

21. The apparatus of claim 20, further comprising:

means for generating a pseudo-random number (PN) sequence for each pilot based on the set of bits of the information to send in the pilot, wherein the pilot sequence for each pilot comprises the PN sequence for the pilot, and

means for generating each pilot based on the PN sequence for the pilot.

22. A non-transitory processor-readable medium including instructions stored thereon, comprising:

instructions for generating a first pilot sequence based on a first set of bits of information to send;

instructions for generating a second pilot sequence based on a second set of bits of the information, the second set of bits being different from the first set of bits, the second pilot sequence being different from the first pilot sequence;

instructions for generating a third pilot sequence based on all bits of the information, the third pilot sequence being different from the first pilot sequence and also different from the second pilot sequence;

instructions for generating a first pilot based on the first pilot sequence;

instructions for generating a second pilot based on the second pilot sequence;

wherein the first and second pilot sequences are generated based on non-overlapping sets of bits of the information;

instructions for generating a third pilot based on the third pilot sequence; and

instructions for sending the first, second, and third pilots in first, second, and third time intervals, respectively.