SCRAMBLING METHODS FOR SYNCHRONIZATION CHANNELS

• US 20080291945A1
• Filed: 02/08/2008
• Published: 11/27/2008
• Est. Priority Date: 05/25/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Luo, Tao
• Granted Patent: US 7,920,598 B2
• Time in Patent Office: Days
• US Class Current: 370/509
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655

Abstract

Systems and methods are provided that facilitate generation and detection of synchronization channels in a wireless communication system. A one-to-one relationship is established among a set of scrambling codes (SCs) and a set of primary synchronization channel (P-SCH) sequences which are determined by a reusable sector identifier that is determined through detection of the P-SCH channel. The set of scrambling codes are utilized to (i) scramble a secondary synchronization channel sequence which facilitates detection of the S-SCH sequence once the reusable sector identifier is detected, or (ii) compose an unscrambled S-SCH sequence through a sequential or interleaved concatenation of SCs wherein a concatenation indication is received in a mobile terminal. Cyclic shifts and sign-flip operations applied to a base sequence are employed to generate SCs. A lookup table and a library of SCs facilitate scrambling code determination in a mobile terminal that receives associated P-SCH and S-SCH sequences.

Claims

1. A method for generating synchronization channels in a wireless communication system, the method comprising:

generating a set of primary synchronization channel (P-SCH) sequences;

generating an association among the generated set of primary synchronization sequences and a set of scrambling codes;

generating a set of secondary synchronization channel sequences (S-SCH); and

scrambling each element in the set of S-SCH sequences with the set of scrambling codes.

2. The method of claim 1, wherein each element in the set of P-SCH sequences is identified with a sector index.

3. The method of claim 1, wherein the association among the generated set of P-SCH sequences and the set of scrambling codes is a one-to-one relationship.

4. The method of claim 1, wherein generating a set of P-SCH sequences comprises generating an element in the set by applying a sign-flip operation to a base sequence.

5. The method of claim 1, wherein generating a set of P-SCH sequences comprises generating an element in the set by applying a conjugate cyclic shift to a base sequence.

6. The method of claim 1, wherein generating a set of S-SCH sequences comprises generating an element in the set by applying a sign-flip operation to a base sequence.

7. The method of claim 1, wherein generating a set of S-SCH sequences comprises generating an element in the set by applying a conjugate cyclic shift to a base sequence.

8. The method of claim 1, further comprising issuing a concatenation indication for concatenating two or more elements in a set of sequences associated with the set of P-SCH sequences to generate a set of S-SCH sequences.

9. The method of claim 8, the generated set of S-SCH sequences comprising unscrambled sequences.

10. The method of claim 8, wherein concatenating two or more elements in the set of sequences associated with the set of P-SCH sequences to generate a set of S-SCH sequences includes:

performing the concatenation sequentially; and

effecting a cyclic shift of the scrambling sequences sequentially concatenated.

11. The method of claim 8, wherein concatenating two or more elements in the set of sequences associated with the set of P-SCH sequences to generate a set of S-SCH sequences includes an interleaved concatenation.

12. The method of claim 1, wherein the set of P-SCH sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

13. The method of claim 1, wherein the set of scrambling sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

14. The method of claim 8, wherein the set of sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

15. The method of claim 1, wherein the set of S-SCH sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

16. The method of claim 1, further comprising generating the set of scrambling sequences.

17. The method of claim 16, wherein generating the set of scrambling codes comprises generating an element in the set by applying a sign-flip operation to a base sequence.

18. The method of claim 16, wherein generating the set of scrambling codes comprises generating an element in the set by applying a conjugate cyclic shift to a base sequence.

19. The method of claim 10, further comprising conveying the issued concatenation indication.

20. The method of claim 1, further comprising conveying at least an element in the set of P-SCH sequences.

21. The method of claim 1, further comprising conveying at least an element in the set of S-SCH sequences.

22. An apparatus that operates in a wireless communication system, the apparatus comprising:

a processor configured to generate a set of primary synchronization channel (P-SCH) sequence, to generate a set of scrambling codes and associate each element in the set to an element in the set of P-SCH sequences;

to generate a set of secondary synchronization channels, and to scramble at least one element in the set of S-SCH with the generated set of scrambling codes; and

a memory coupled to the processor.

23. The apparatus of claim 22, wherein each element in the set of P-SCH sequences is identified with a sector index.

24. The apparatus of claim 22, the processor further configured to generate a concatenation indication, wherein the concatenation indication conveys a concatenation protocol to combine two or more sequences in a set of sequences associated with the set of P-SCH sequences to form a S-SCH sequence.

25. The apparatus of claim 24, wherein the concatenation protocol comprises at least one of a sequential concatenation of the two or more sequences or an interleaved concatenation.

26. The apparatus of claim 25, wherein the concatenation protocol further comprises at least one of a cyclic left-shift or a cyclic right-shift of the two or more sequences.

27. The apparatus of claim 22, wherein the set of P-SCH sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

28. The apparatus of claim 22, wherein the set of S-SCH sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

29. The apparatus of claim 22, wherein the set of scrambling sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

30. The apparatus of claim 24, wherein the set of sequences associated with the set of P-SCH sequences comprises at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

31. The apparatus of claim 26, the processor further configured to convey the generated concatenation indication.

32. The apparatus of claim 22, the processor further configured to convey at least one of an element of the set of P-SCH sequences or an element of the set of S-SCH sequences.

33. A computer program product, including a computer-readable medium comprising:

code for causing a computer to generate a set of primary synchronization channel (P-SCH) sequences, each element in the set of P-SCH sequences is identified with a reusable communication sector index;

code for causing a computer to generate a one-to-one association among the generated set of primary synchronization sequences and a set of scrambling codes;

code for causing a computer to generate a set of secondary synchronization channel sequences (S-SCH); and

code for causing a computer to scramble each element in the set of S-SCH sequences with the set of scrambling codes.

34. The computer program product of claim 33, further comprising code for causing a computer to issue a concatenation indication, wherein the concatenation indication conveys a concatenation protocol to combine two or more sequences associated with a set of P-SCH sequences to form a S-SCH sequence.

35. The computer program of claim 34, further comprising code for causing a computer to execute concatenation protocol, wherein the concatenation protocol includes:

performing the concatenation sequentially; and

effecting a cyclic shift of the two or more sequences sequentially concatenated.

36. A wireless communication device comprising:

means for generating a set of primary synchronization codes (PSCs), wherein each the PSCs in the set is indexed with a wireless communication reusable sector identifier;

means for generating a set of scrambling codes, the set associated in a one-to-one relationship with the set of PSCs;

means for generating a set of secondary synchronization codes (SSCs);

means for scrambling an element in the set of SSCs with a subset of the set of scrambling codes;

means for conveying an element of the set of PSCs, an element of the set of SSCs.

37. A method for processing synchronization channels transmitted in a wireless communication environment, the method comprising:

receiving a set of primary synchronization channel (P-SCH) sequences and a set of secondary synchronization channel (S-SCH) sequences, wherein each element in the set of P-SCH sequences is indexed with a sector identifier;

decoding the received set of P-SCH sequences and determining the associated sector identifier;

establishing a scrambling code associated with each determined sector identifier;

decoding the received set of S-SCH sequences by employing the established scrambling codes to unscramble the received set of sequences.

38. The method of claim 37, wherein establishing a scrambling code associated with each determined sector identifier comprises employing said identifier as a key to a lookup table that reveals a one-to-one association among a P-SCH sequence and a scrambling code.

39. The method of claim 38, further comprising employing the key to the lookup table to extract the scrambling code from a scrambling code library.

40. The method of claim 37, further comprising receiving a S-SCH concatenation indication, the concatenation indication conveys a concatenation protocol to generate a secondary synchronization sequence by concatenating two or more sequences in a set of sequences that present a one-to-one relationship with a set of P-SCH sequences.

41. The method of claim 40, wherein the received concatenation protocol comprises:

performing the concatenation sequentially; and

effecting a cyclic shift of the two or more sequences sequentially concatenated.

42. The method of claim 40, wherein the received concatenation protocol comprises performing an interleaved concatenation.

43. The method of claim 40, the set of P-SCH sequences comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

44. The method of claim 40, the set of S-SCH sequences comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

45. The method of claim 40, the established scrambling code comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

46. The method of claim 40, a sequence in the set of sequences that present a one-to-one relationship with a set of P-SCH sequences comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

47. A computer program product, including a computer-readable medium comprising:

code for causing a computer to receive a set of primary synchronization channel (P-SCH) sequences and a set of secondary synchronization channel (S-SCH) sequences, wherein each element in the set of P-SCH sequences is indexed with a sector identifier;

code for causing a computer to decode the received set of P-SCH sequences and determining the associated sector identifier;

code for causing a computer to establish a scrambling code associated with each determined sector identifier;

code for causing a computer to decode the received set of S-SCH sequences by employing the established scrambling codes to unscramble the received set of sequences.

48. A wireless communication device comprising:

a processor configured to receive a set of primary synchronization channel (P-SCH) sequences and a set of secondary synchronization channel (S-SCH) sequences, wherein each element in the set of P-SCH sequences is indexed with a sector identifier;

to decode the received set of P-SCH sequences and determining the associated sector identifier;

to establish a scrambling code associated with each determined sector identifier; and

to decode the received set of S-SCH sequences by employing the established scrambling codes to unscramble the received set of sequences; and

a memory coupled to the processor.

49. The wireless communication device of claim 48, the processor further configured to receive a S-SCH concatenation indication, wherein the concatenation indication conveys a concatenation protocol to generate a secondary synchronization sequence by sequential or interleaved concatenation two or more of the established scrambling codes.

50. The wireless communication device of claim 48, further comprising a lookup table stored in the memory coupled to the processor, the lookup table facilitates to identify a scrambling code.

51. The wireless communication device of claim 48, further comprising a library of scrambling codes stored in the memory coupled to the processor.

52. The wireless communication device of claim 48, the set of P-SCH sequences comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

53. The wireless communication of claim 48, the set of S-SCH sequences comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

54. The wireless communication device of claim 48, wherein the established scrambling code comprising at least one of a Walsh-Hadamard sequence, a Gold sequence, a Rice sequence, a Golomb sequence, an M-sequence, a pseudonoise sequence, or a generalized Chirp-like sequence.

55. An apparatus that operates in a wireless environment, the apparatus comprising:

means for receiving a set of primary synchronization codes (PSCs) and a set of secondary synchronization codes (SSCs), wherein each element in the set of PSCs is indexed with a sector identifier;

means for decoding the received set of PSCs and determining the associated sector identifier;

means for establishing a scrambling code associated with each determined sector identifier;

means for decoding the received set of SSCs by employing the established scrambling codes to unscramble the received set of sequences; and

means for storing a lookup table that facilitates to identify a scrambling code and a library of scrambling codes.