Scrambling methods for synchronization channels
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.
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; anda 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 non-transitory 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; and
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; and
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 non-transitory 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; and
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; anda 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.