METHOD AND APPARATUS FOR PERFORMING CELL SEARCH IN WIRELESS COMMUNICATION SYSTEM

• US 20180270008A1
• Filed: 09/02/2016
• Published: 09/20/2018
• Est. Priority Date: 09/02/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: YI, Yunjung, KIM, Bonghoe, KO, Hyunsoo
• Granted Patent: US 10,673,671 B2
• Time in Patent Office: Days
• 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 27/2659 Coarse or integer frequency offset determination and synchronisation
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

A method and apparatus for performing a cell search in a wireless communication system is provided. A narrowband user equipment (NB UE) performs the cell search at a specific frequency with a fixed frequency offset, and moves to the specific frequency with the fixed frequency offset and a channel raster.

Claims

1. A method for performing, by a narrowband user equipment (NB UE), a cell search in a wireless communication system, the method comprising:

performing the cell search at a specific frequency with a fixed frequency offset; and

moving to the specific frequency with the fixed frequency offset and a channel raster.

2. The method of claim 1, wherein the channel raster is set as 100 kHz.

3. The method of claim 2, wherein the fixed frequency offset is set as one of 180 kHz*3 or 180 kHz*3+90 kHz.

4. The method of claim 2, wherein the fixed frequency offset is set as 7.5 kHz.

5. The method of claim 2, wherein the channel raster is changed into 10 kHz or multiple of 90 kHz.

6. The method of claim 1, wherein performing the cell search comprises searching a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

7. The method of claim 1, wherein a fixed narrowband in the specific frequency is configured for the NB UE.

8. A narrowband user equipment (NB UE) in a wireless communication system, the NB UE comprising:

a memory;

a transceiver; and

a processor, coupled to the memory and the transceiver, that;

performs the cell search at a specific frequency with a fixed frequency offset, and moves to the specific frequency with the fixed frequency offset and a channel raster.

9. The NB UE of claim 8, wherein the channel raster is set as 100 kHz.

10. The NB UE of claim 9, wherein the fixed frequency offset is set as one of 180 kHz*3 or 180 kHz*3+90 kHz.

11. The NB UE of claim 9, wherein the fixed frequency offset is set as 7.5 kHz.

12. The NB UE of claim 9, wherein the channel raster is changed into 10 kHz or multiple of 90 kHz.

13. The NB UE of claim 8, wherein performing the cell search comprises searching a primary synchronization signal (PSS) or a secondary synchronization signal (SSS).

14. The NB UE of claim 8, wherein a fixed narrowband in the specific frequency is configured for the NB UE.