GENERATING DOWNLINK FRAME AND SEARCHING FOR CELL

• US 20130100902A1
• Filed: 10/22/2012
• Published: 04/25/2013
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: CHANG, Kap Seok, KIM, Il Gyu, PARK, Hyeong Geun, KO, Young Jo, YI, Hyo Seok, JEONG, Chan Bok, KIM, Young Hoon, BANG, Seung Chan
• Granted Patent: US 9,144,064 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• 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
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 7/043 Pseudo-noise [PN] codes variable during transmission synchronisation of spread spectrum receivers H04B1/69
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method is provided for searching for a cell in a mobile station. The method includes receiving a downlink frame including a primary synchronization signal and a secondary synchronization signal. The secondary synchronization signal contains cell identity group information and the primary synchronization signal contains cell identity information within a cell identity group. The method also includes searching for a cell using the cell identity group information in the secondary synchronization signal and the cell identity information in the primary synchronization sign.

Claims

1. A method of searching for a cell in a mobile station, comprising:

receiving a downlink frame including a primary synchronization signal and a secondary synchronization signal, wherein the secondary synchronization signal contains cell identity group information and the primary synchronization signal contains cell identity information within a cell identity group; and

searching for a cell using the cell identity group information in the secondary synchronization signal and the cell identity information in the primary synchronization signal,

wherein the secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence,

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, and the third scrambling sequence is determined based on the first short sequence.

2. The method of claim 1, wherein the first short sequence scrambled with the first scrambling sequence and the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence are alternately disposed on a plurality of sub-carriers.

3. The method of claim 1, wherein the first scrambling sequence is different from the second scrambling sequence.

4. The method of claim 1, wherein the downlink frame includes a plurality of slots, each slot having a plurality of symbols,

wherein the primary synchronization signal is located on a last symbol of a slot, and the secondary synchronization signal is located on a symbol right ahead of the last symbol of the slot.

5. The method of claim 1, wherein the downlink frame comprises a second secondary synchronization signal containing the cell identity group information,

wherein the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence, and the first short sequence is scrambled with the second scrambling sequence and a fourth scrambling sequence, and

wherein the fourth scrambling sequence is determined based on the second short sequence.

6. The method of claim 5, wherein the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and the fourth scrambling sequence are alternately disposed on a plurality of sub-carriers.

7. The method of claim 5, further comprising:

identifying the cell identity group using at least one of the first secondary synchronization signal and the second secondary synchronization signal.

8. The method of claim 5, wherein the second secondary synchronization signal is different from the first secondary synchronization signal.

9. A method of searching for a cell by a mobile station in a wireless communication system, wherein the wireless communication system uses a plurality of short sequences grouped into a plurality of short sequence groups, the method comprising:

receiving a downlink frame including a primary synchronization signal and a secondary synchronization signal, wherein the secondary synchronization signal contains cell identity group information and the primary synchronization signal contains cell identity information within a cell identity group; and

searching for a cell using the cell identity group information in the secondary synchronization signal and the cell identity information in the primary synchronization signal,

wherein the secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence,

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, and the third scrambling sequence is determined based on a short sequence group to which the first short sequence is assigned and is determined based on a remainder of dividing an index of the first short sequence by 8.

10. The method of claim 9, wherein the wireless communication system has 31 short sequences, and the index of the first short sequence has one value among 0 to 30.

11. The method of claim 10, wherein short sequences within the short sequence group have the same remainder.

12. The method of claim 9, wherein the downlink frame comprises a second secondary synchronization signal containing the cell identity group information,

wherein the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence,

wherein the fourth scrambling sequence is determined based on a short sequence group to which the second short sequence is assigned and is determined based on a remainder of diving an index of the second short sequence by 8.

13. The method of claim 12, wherein the wireless communication system has 31 short sequences, and the index of the second short sequence has one value among 0 to 30.

14. The method of claim 13, wherein short sequences within the short sequence group have the same remainder.

15. A method of searching for a cell by a mobile station in a wireless communication system, the method comprising:

receiving a downlink frame including a primary synchronization signal, a first secondary synchronization signal and a second secondary synchronization signal, wherein each of the first and second secondary synchronization signals contains cell identity group information and the primary synchronization signal contains cell identity information within a cell identity group; and

searching for a cell using the cell identity group information and the cell identity information, the cell identity group information being identified using at least one of the first secondary synchronization signal and the second secondary synchronization signal, and the cell identity information being identified using the primary synchronization signal,

wherein the first secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence, and

the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence, and the first short sequence is scrambled with the second scrambling sequence and a fourth scrambling sequence, and

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, the third scrambling sequence is determined based on a remainder of dividing an index of the first short sequence by 8, the fourth scrambling sequence is determined based on a remainder of dividing an index of the second short sequence by 8.

16. The method of claim 15, wherein the first short sequence scrambled with the first scrambling sequence and the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence in the first secondary synchronization signal are alternately disposed on a plurality of sub-carriers, and the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence in the second secondary synchronization signal are alternately disposed on a plurality of sub-carriers.

17. The method of claim 15, wherein the first scrambling sequence is different from the second scrambling sequence.

18. The method of claim 15, wherein the downlink frame includes a plurality of slots, each slot having a plurality of symbols,

wherein the primary synchronization signal is located on a last symbol of a first slot and the first secondary synchronization signal is located on a symbol right ahead of the last symbol of the first slot, and

the primary synchronization signal is located on a last symbol of a second slot and the second secondary synchronization signal is located on a symbol right ahead of the last symbol of the second slot.

19. The method of claim 15, wherein the second secondary synchronization signal is different from the first secondary synchronization signal.

20. The method of claim 15, wherein the wireless communication system has 31 short sequences, and

the index of the first short sequence has one value among 0 to 30, and the index of the second short sequence has one value among 0 to 30.

21. A method of generating a down link frame in a base station, comprising:

including cell identity group information in a secondary synchronization signal and including cell identity information within a cell identity group in a primary synchronization signal so that a terminal searches for a cell using the cell identity group information in the secondary synchronization signal and the cell identity information in the primary synchronization signal; and

generating a downlink frame including the primary synchronization signal and the secondary synchronization signal,

wherein the secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence,

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, and the third scrambling sequence is determined based on the first short sequence.

22. The method of claim 21, wherein the first short sequence scrambled with the first scrambling sequence and the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence are alternately disposed on a plurality of sub-carriers.

23. The method of claim 21, wherein the first scrambling sequence is different from the second scrambling sequence.

24. The method of claim 21, wherein the downlink frame includes a plurality of slots, each slot having a plurality of symbols,

wherein the primary synchronization signal is located on a last symbol of a slot, and the secondary synchronization signal is located on a symbol right ahead of the last symbol of the slot.

25. The method of claim 21, wherein the downlink frame comprises a second secondary synchronization signal containing the cell identity group information,

wherein the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence, and the first short sequence is scrambled with the second scrambling sequence and a fourth scrambling sequence, and

wherein the fourth scrambling sequence is determined based on the second short sequence.

26. The method of claim 25, wherein the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and the fourth scrambling sequence are alternately disposed on a plurality of sub-carriers.

27. The method of claim 25, wherein the cell identity group is identified using at least one of the first secondary synchronization signal and the second secondary synchronization signal.

28. The method of claim 25, wherein the second secondary synchronization signal is different from the first secondary synchronization signal.

29. A method of generating a downlink frame in a wireless communication system, wherein the wireless communication system uses a plurality of short sequences grouped into a plurality of short sequence groups, the method comprising:

including cell identity group information in a secondary synchronization signal and including cell identity information within a cell identity group in a primary synchronization signal so that a terminal searches for a cell using the cell identity group information in the secondary synchronization signal and the cell identity information in the primary synchronization signal; and

generating a downlink frame including the primary synchronization signal and the secondary synchronization signal,

wherein the secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence,

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, and the third scrambling sequence is determined based on a short sequence group to which the first short sequence is assigned and is determined based on a remainder of dividing an index of the first short sequence by 8.

30. The method of claim 29, wherein the wireless communication system has 31 short sequences, and the index of the first short sequence has one value among 0 to 30.

31. The method of claim 30, wherein short sequences within the short sequence group have the same remainder.

32. The method of claim 29, wherein the downlink frame comprises a second secondary synchronization signal containing the cell identity group information,

wherein the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence,

wherein the fourth scrambling sequence is determined based on a short sequence group to which the second short sequence is assigned and is determined base on a remainder of diving an index of the second short sequence by 8.

33. The method of claim 32, wherein the wireless communication system has 31 short sequences, and the index of the second short sequence has one value among 0 to 30.

34. The method of claim 33, wherein short sequences within the short sequence group have the same remainder.

35. A method of generating a downlink frame in a wireless communication system, the method comprising:

including cell identity group information in each of the first and second secondary synchronization signals and including cell identity information within a cell identity group in a primary synchronization signal so that a terminal searches for a cell using the cell identity group information and the cell identity information;

generating a downlink frame including the primary synchronization signal, the first secondary synchronization signal and the second secondary synchronization signal,

wherein the cell identity group information is identified using at least one of the first secondary synchronization signal and the second secondary synchronization signal, and the cell identity information is identified using the primary synchronization signal,

wherein the first secondary synchronization signal comprises a first short sequence and a second short sequence, the first short sequence is scrambled with a first scrambling sequence, and the second short sequence is scrambled with a second scrambling sequence and a third scrambling sequence,

wherein the second secondary synchronization signal comprises the first short sequence and the second short sequence, the second short sequence is scrambled with the first scrambling sequence, and the first short sequence is scrambled with the second scrambling sequence and a fourth scrambling sequence, and

wherein the first scrambling sequence and the second scrambling sequence are determined based on the cell identity information contained in the primary synchronization signal, the third scrambling sequence is determined based on a remainder of dividing an index of the first short sequence by 8, and the fourth scrambling sequence is determined based on a remainder of dividing an index of the second short sequence by 8.

36. The method of claim 35, wherein the first short sequence scrambled with the first scrambling sequence and the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence in the first secondary synchronization signal are alternately disposed on a plurality of sub-carriers, and the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence in the second secondary synchronization signal are alternately disposed on a plurality of sub-carriers.

37. The method of claim 35, wherein the first scrambling sequence is different from the second scrambling sequence.

38. The method of claim 35, wherein the downlink frame includes a plurality of slots, each slot having a plurality of symbols,

wherein the primary synchronization signal is located on a last symbol of a first slot and the first secondary synchronization signal is located on a symbol right ahead of the last symbol of the first slot, and

the primary synchronization signal is located on a last symbol of a second slot and the second secondary synchronization signal is located on a symbol right ahead of the last symbol of the second slot.

39. The method of claim 35, wherein the second secondary synchronization signal is different from the first secondary synchronization signal.

40. The method of claim 35, wherein the wireless communication system has 31 short sequences, and

the index of the first short sequence has one value among 0 to 30, and the index of the second short sequence has one value among 0 to 30.