Method for receiving system information in wireless communication system that supports narrowband IOT and apparatus for the same

1. A method for receiving system information in a wireless communication system supporting a Narrow Band (NB)-Internet of Things (IoT), the method performed by a terminal comprising:

receiving a narrowband synchronization signal (NBSS) through a narrowband (NB) from a base station;

acquiring, based on the NBSS, time synchronization and frequency synchronization with the base station; and

receiving the system information related to the NB-IoT through a narrowband physical broadcast channel (N-PBCH) from the base station,

wherein the system information includes operation mode information indicating an operation mode of the NB-1° T system and control information indicating an index of a legacy CRS (cell-specific reference signal) sequence, and

wherein the control information is associated with a PRB (physical resource block) index of a PRB to which the legacy CRS is transmitted.

2. The method of claim 1 , wherein the PRB index is related to a frequency difference between a center frequency of the PRB and a direct current (DC).

3. The method of claim 2 , wherein the control information includes channel raster offset information.

4. The method of claim 3 , wherein the channel raster offset is +2.5 kHz, +7.5 kHz, −2.5 kHz or −7.5 kHz.

5. The method of claim 4 , wherein the operation mode is an in-band mode, a guardband mode or a stand-alone mode.

6. The method of claim 5 , wherein the in-band mode includes a first in-band mode in which the NB-IoT system and LTE system have a same Physical Cell ID (PCI) and a second in-band mode in which the NB-IoT system and LTE system have different Physical Cell IDs (PCIS).

7. The method of claim 6 , wherein the control information is included in the system information, when the operation mode is the first in-band mode.

8. The method of claim 4 , wherein the PRB index is sorted out by the channel raster information.

9. The method of claim 1 , wherein the narrowband is a system bandwidth that corresponds to 1 Physical Resource Block (PRB) of Long Term Evolution (LTE) system.

10. The method of claim 9 , wherein the 1 PRB includes 12 subcarriers.

11. The method of claim 10 , wherein the narrowband synchronization signal includes a narrowband primary synchronization signal and a narrowband secondary synchronization signal.

12. The method of claim 11 , wherein the narrowband primary synchronization signal is received through 11 contiguous subcarriers among the 12 subcarriers.

13. A terminal for receiving system information in a wireless communication system supporting a narrowband (NB)-Internet of Things (IoT), comprising:

a Radio Frequency (RF) unit for transmitting and receiving a radio signal; and

a processor for controlling the RF unit,

wherein the processor is configured to perform:

receiving a narrowband synchronization signal (NBSS) through a narrowband (NB) from a base station;

acquiring, based on the NBSS, time synchronization and frequency synchronization with the base station; and

receiving the system information related to the NB-IoT through a narrowband physical broadcast channel (N-PBCH) from the base station,

wherein the system information includes operation mode information indicating an operation mode of the NB-IoT system and control information indicating an index of a legacy CRS (cell-specific reference signal) sequence, and

wherein the control information is associated with a PRB (physical resource block) index of a PRB to which the legacy CRS is transmitted.

14. The terminal of claim 13 , wherein the PRB index is in relation to a frequency difference between a center frequency of the PRB and a Direct Current (DC).

15. The terminal of claim 14 , wherein the control information includes channel raster offset information.