Method for obtaining information about cyclic prefix in wireless communication system and device for same

1. A method for obtaining information for a cyclic prefix (CP) in a wireless communication system by a terminal, the method comprising:

detecting a specific synchronization signal received from a base station via a first symbol of a first subframe;

detecting the specific synchronization signal received from the base station via a second symbol of a second subframe; and

obtaining information for the CP applied to transmission of the specific synchronization signal, based on an offset value between an index of the first symbol and an index of the second symbol,

wherein the second subframe includes a subframe in which a symbol index is permuted based on a preconfigured pattern for the CP, and

wherein the offset value between the index of the first symbol and the index of the second symbol indicates a CP type for the CP among one or more CP types supported in the wireless communication system.

2. The method of claim 1 , wherein in the first subframe, the specific synchronization signal is transmitted by using a first beam set configured by a plurality of beams allocated to a plurality of symbols of the first subframe, respectively, and

in the second subframe, the specific synchronization signal is transmitted by using a second beam set configured by a plurality of beams allocated to a plurality of symbols of the second subframe, respectively, and

wherein the first beam set and the second beam set are configured for different CP types, respectively.

3. The method of claim 2 , wherein a beam allocated to the first symbol among the plurality of beams of the first beam set is identical to a beam allocated to the second symbol among the plurality of beams of the second beam set.

4. The method of claim 3 , wherein the beam allocated to the first symbol and the beam allocated to the second symbol include a specific beam in which a signal detected by the terminal is transmitted among the a plurality of beams of the base station.

5. The method of claim 2 , wherein the detecting of the specific synchronization signal comprises detecting a peak value among values for the specific value for the specific signal.

6. The method of claim 3 , wherein candidates of the offset value between the index of the first symbol and the index of the second symbol are preconfigured between the base station and the terminal, and

wherein the candidates are mapped for each CP type.

7. The method of claim 2 , wherein a difference value between a timing when the first subframe is transmitted and a timing when the second subframe is transmitted is defined as a multiple of a transmission period of the specific synchronization signal.

8. The method of claim 3 , wherein the second beam set includes a beam set in which the plurality of beams of the first beam set are permuted based on the preconfigured pattern.

9. The method of claim 1 , further comprising:

receiving, from the base station, a synchronization signal including information-related to the second subframe.

10. The method of claim 1 , further comprising:

detecting the specific synchronization signal received from the base station via a third symbol of the first subframe, wherein a difference between the third symbol and the first symbol corresponds to a symbol length corresponding to a specific CP;

calculating a sum of a peak value for the specific synchronization signal received via the first symbol and a peak value for the specific synchronization signal received via the third symbol; and

determining, when the calculated sum is larger than a preconfigured threshold value, whether a temporary CP matches the CP obtained based on the offset value by determining the specific CP as the temporary CP for the specific synchronization signal.

11. A terminal for obtaining information for a cyclic prefix (CP) in a wireless communication system, the terminal comprising:

a transceiver for transmitting and receiving a radio signal; and

a processor functionally connected to the transceiver,

wherein the processor controls to:

detect a specific synchronization signal received from a base station via a first symbol of a first subframe,

detect the specific synchronization signal received from the base station via a second symbol of a second subframe, and

obtain information for the CP applied to transmission of the specific synchronization signal based on an offset value between an index of the first symbol and an index of the second symbol,

wherein the second subframe includes a subframe in which a symbol index is permuted based on a preconfigured pattern for the CP, and

wherein the offset value between the index of the first symbol and the index of the second symbol indicates a CP type for the CP among one or more CP types supported in the wireless communication system.