Method for signal transmission/reception between base station and terminal in wireless communication system supporting unlicensed band, and apparatus supporting same
Disclosed are a method for signal transmission/reception between a terminal and a base station in a wireless communication system supporting an unlicensed band, and apparatuses supporting the same. Particularly, disclosed are a method for transmitting/receiving a signal and apparatuses supporting the same, wherein a base station transmits a synchronization signal/physical broadcast channel block through an unlicensed band, and a terminal is synchronized with the base station on the basis of the transmitted synchronization signal/physical broadcast channel block.
1. A method for receiving synchronization signals by a user equipment (UE) in a wireless communication system supporting an unlicensed band, the method comprising:
obtaining information regarding a number of synchronization signal/physical broadcast channel (SS/PBCH) blocks transmitted in a preconfigured transmission time duration, wherein the number of the SS/PBCH blocks transmitted in the preconfigured transmission time duration is N; and
receiving a SS/PBCH block via the unlicensed band in the preconfigured transmission time duration,
wherein an index of the SS/PBCH block is determined based on the value of N, and
wherein the value of N is smaller than a maximum transmission number of the SS/PBCH blocks determined based on a frequency band.
2. The method of claim 1 , wherein,
(i) based on the SS/PBCH block transmitted in a frequency band below 3 GHz, the maximum transmission number of the SS/PBCH blocks is configured as 4,
(ii) based on the SS/PBCH block transmitted in a frequency band above 3 GHz and below 6 GHz, the maximum transmission number of the SS/PBCH blocks is configured as 8, and
(iii) based on the SS/PBCH block transmitted in a frequency band above 6 GHz, the maximum transmission number of the SS/PBCH blocks is configured as 64.
3. The method of claim 1 ,
wherein the SS/PBCH block is received in one of a plurality of SS/PBCH block transmission positions within the preconfigured transmission time duration,
wherein the one of the plurality of SS/PBCH block transmission positions within the preconfigured transmission time duration is greater than or equal to the value of N, and
wherein the index of the SS/PBCH block is less than the value of N.
4. The method of claim 1 , further comprising:
obtaining the information regarding the number of the SS/PBCH blocks transmitted in the preconfigured transmission time duration based on at least one of:
(i) PBCH information included in the SS/PBCH block, or
(ii) demodulation reference signal (DM-RS) information for the PBCH included in the SS/PBCH block.
5. A method for transmitting synchronization signals by a base station (BS) in a wireless communication system supporting an unlicensed band, the method comprising:
transmitting, to a user equipment (UE), information regarding a number of synchronization signal/physical broadcast channel (SS/PBCH) blocks transmitted in a preconfigured transmission time duration, wherein the number of the SS/PBCH blocks transmitted in the preconfigured transmission time duration is N;
performing a channel access procedure (CAP) for transmitting a SS/PBCH block via the unlicensed band; and
transmitting, to the UE, the SS/PBCH block via the unlicensed band in the preconfigured transmission time duration, based on a result of the CAP,
wherein an index of the SS/PBCH block is determined based on the value of N, and
wherein the value of N is smaller than a maximum transmission number of the SS/PBCH blocks determined based on a frequency band.
6. The method of claim 5 ,
wherein the SS/PBCH block is received in one of a plurality of SS/PBCH block transmission positions within the preconfigured transmission time duration,
wherein the one of the plurality of SS/PBCH block transmission positions within the preconfigured transmission time duration is greater than or equal to the value of N, and
wherein the index of the SS/PBCH block is less than the value of N.
7. A base station (BS) for transmitting synchronization signals in a wireless communication system supporting an unlicensed band, the base station comprising:
at least one radio frequency (RF) module;
at least one processor; and
at least one memory operably connectable to the at least one processor and storing instructions that, when executed, cause the at least one processor perform operations comprising:
transmitting, to a user equipment (UE), information regarding a number of synchronization signal/physical broadcast channel (SS/PBCH) blocks transmitted in a preconfigured transmission time duration, wherein the number of the SS/PBCH blocks transmitted in the preconfigured transmission time duration is N;
performing a channel access procedure (CAP) for transmitting a SS/PBCH block via the unlicensed band; and
transmitting, to the UE, the SS/PBCH block via the unlicensed band in the preconfigured transmission time duration, based on a result of the CAP,
wherein an index of the SS/PBCH block is determined based on the value of N, and
wherein the value of N is smaller than a maximum transmission number of the SS/PBCH blocks determined based on a frequency band.