METHOD FOR ENABLING A TERMINAL TO EFFICIENTLY DETECT AND SEARCH FOR A FEMTO BASE STATION

• US 20110243108A1
• Filed: 11/16/2009
• Published: 10/06/2011
• Est. Priority Date: 12/10/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Jin, Park, Sung Ho, Ihm, Bin Chul, Chun, Jin Young, Kim, Yong Ho
• Granted Patent: US 9,014,153 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

A method for enabling a mobile station (MS) to efficiently detect and search for a femto base station is disclosed. The method comprises the steps of receiving a signal including information of a femto base station; and searching for the femto base station on the basis of the received information, wherein said received information is a sequence including at least one of the following: the entirety or a part of a femto base station ID (Identity), the entirety or a part of a cell ID, a sector ID, the entirety or a part of a CSG (Closed Subscriber Group) ID, and a frequency allocation index. In the step of receiving femto base station information, a preamble and data containing information on the femto base station are received. In the step of detecting the femto base station, the femto base station is separately detected on the basis of the received information. Here, the entirety or a part of the preamble sequence of the femto base station which is used for the separation of the femto base station is reused as a scrambling sequence for said data.

Claims

1. A method of searching for a femto base station, the method comprising:

receiving a signal including information on the femto base station; and

searching for the femto base station based on the received information,

wherein the received information is a sequence including at least one the entirety or a part of a femto base station ID (Identity), the entirety or a part of a cell ID, a sector ID, the entirety or a part of a closed subscriber group (CSG) ID, and a frequency allocation index.

2. The method of claim 1, wherein the sequence includes at least one of a status indicator indicating whether a femto cell is active and a femto type indicator indicating open subscriber group (OSG) type or CSG type.

3. The method of claim 1, wherein the sequence further includes the femto type indicator when the CSG ID is included in the sequence.

4. The method of claim 1, wherein the sequence further includes at least one of a femto cell indicator indicating a macro cell or a femto cell and a femto type indicator when the cell ID is included in the sequence.

5. The method of claim 1, wherein the received signal further includes a message, and the message further includes at least one of the cell ID, a femto cell status indicator, a frequency allocation index for frequency allocation (FA) to which the femto cell belongs, and cyclic redundancy check (CRC).

6. The method of claim 5, wherein a part of the CSG ID is included in the message when the CSG ID is included in the sequence.

7. The method of claim 5, wherein the sequence is used as a scrambling code.

8. The method of claim 1, wherein a resource region of a downlink for transmitting information of the femto base station is allocated by one of FDM mode, CDM mode and TDM mode for the frequency allocation index or sector index.

9. The method of claim 5 wherein a resource region of a downlink for transmitting information of the femto base station is allocated by one of FDM mode, CDM mode and TDM mode for the frequency allocation index or sector index.

10. The method of claim 5, wherein a multiplexing mode applied to the message included in the received signal is different from that applied to a preamble sequence.

11. A method for searching for a femto base station, the method comprising:

receiving a preamble including identification information of the femto base station and data; and

searching for the femto base station by identifying the femto base station based on the received information,

wherein the entirety or a part of the preamble sequence of the femto base station, which is used for identification of the femto base station, are reused as a scrambling sequence of the data.

12. The method of claim 11, wherein the preamble sequence is detected as much as a length of the data sequence and then reused as a data scrambling sequence.

13. The method of claim 11, wherein the preamble sequence is detected at an interval of the predetermined integer multiple and then reused as a data scrambling sequence when the preamble sequence has a length corresponding to a predetermined integer multiple of the length of the data sequence.

14. The method of claim 11, wherein the entirety of the preamble sequence is reused as the data scrambling sequence, or a cyclic shift value, which is previously defined, is applied to the preamble sequence, so that the entirety of the cyclic-shifted preamble sequence is reused as the data scrambling sequence.

15. The method of claim 11, wherein, when the data sequence has a length corresponding to a predetermined integer multiple of the length of the preamble sequence, the entirety of the preamble sequence is repeatedly applied as much as the predetermined integer multiple or repeatedly applied per preamble sequence element, so that the preamble sequence is reused as the data scrambling sequence.

16. The method of claim 15, wherein the entirety of the preamble sequence is repeatedly applied or the preamble sequence repeatedly applied per preamble sequence element is cyclic shifted, so that the preamble sequence is reused as the data scrambling sequence.

17. The method of claim 16, wherein the cyclic shifted preamble sequence is configured by block unit combination of a sequence to which a cyclic shift value corresponding to a previously defined basic value is applied and a sequence to which a separately allocated predetermined cyclic shift value is applied.

18. A method of searching for a femto base station, the method comprising:

receiving a preamble including information of the femto base station and data; and

processing the data by identifying the femto base station based on the received information,

wherein a sequence allocated to the femto base station is sequentially allocated to the preamble and data.

19. The method of claim 18, wherein the same cyclic shift value as that of cyclic shift version for sequence index known by the femto base station is applied to the sequence allocated to the femto base station, so that the sequence is allocated to the preamble and the data in the cyclic-shifted order.

20. The method of claim 18, wherein a separate cyclic shift value different from cyclic shift version for sequence index predetermined between the femto base station and a macro base station is applied to the sequence allocated to the femto base station, so that the sequence is allocated to the preamble and the data in the cyclic-shifted order.