Method and apparatus for transmitting and receiving synchronization signal in communication system
The present disclosure relates to a 5G or 6G communication system for supporting data transmission rates higher than that of a 4G communication system such as LTE. More particularly, the present disclosure relates to a method and apparatus in which a base station transmits a synchronization signal via a satellite and a terminal detects the synchronization signal in a communication system.
1 . A method performed by a terminal supporting non-terrestrial network (NTN) communication in a wireless communication system, the method comprising:
identifying a synchronization raster to perform initial access for NTN communication; and
receiving a synchronization signal block (SSB) from a satellite based on the identified synchronization raster,
wherein a position of the synchronization raster is identified by a global synchronization channel number (GSCN),
wherein each GSCN is determined based on a first parameter related to an order of clusters formed by at least one synchronization raster and a second parameter related to an order of synchronization rasters included in a cluster.
2 . The method of claim 1 , wherein a transmission frequency of the SSB is corrected based on a Doppler effect between the satellite and the terminal.
3 . The method of claim 1 , wherein the SSB is transmitted by a base station and received via the satellite.
4 . The method of claim 3 , further comprising receiving, from the base station via the satellite, system information indicating that the base station is a base station for the NTN communication.
5 . The method of claim 1 , wherein in case that a subcarrier spacing (SCS) of the SSB is 15 kHz and a frequency band for the initial access is lower than 3000 MHz, an interval between 1 st synchronization rasters included respectively in two adjacent clusters is greater than 1200 kHz or an interval between two adjacent synchronization rasters included in a cluster is less than 50 kHz.
6 . The method of claim 1 , wherein in case that an SCS of the SSB is 15 kHz and a frequency band for the initial access is lower than 3000 MHz, a maximum value of the first parameter is less than 2499 or a number of synchronization rasters included in a cluster is less than 3.
7 . The method of claim 1 , wherein an interval between two adjacent synchronization rasters included in a cluster is determined based on an altitude of the satellite.
8 . A terminal supporting non-terrestrial network (NTN) communication in a wireless communication system, comprising:
a transceiver to transmit and receive signals; and
a controller connected to the transceiver,
wherein the controller is configured to:
identify a synchronization raster to perform initial access for NTN communication, and
receive a synchronization signal block (SSB) from a satellite based on the identified synchronization raster,
wherein a position of the synchronization raster is identified by a global synchronization channel number (GSCN),
wherein each GSCN is determined based on a first parameter related to an order of clusters formed by at least one synchronization raster and a second parameter related to an order of synchronization rasters included in a cluster.
9 . The terminal of claim 8 , wherein a transmission frequency of the SSB is corrected based on a Doppler effect between the satellite and the terminal.
10 . The terminal of claim 8 , wherein the SSB is transmitted by a base station and received via the satellite.
11 . The terminal of claim 10 , wherein the controller is configured to receive, from the base station via the satellite, system information indicating that the base station is a base station for the NTN communication.
12 . The terminal of claim 8 , wherein in case that a subcarrier spacing (SCS) of the SSB is 15 kHz and a frequency band for the initial access is lower than 3000 MHz, an interval between 1 st synchronization rasters included respectively in two adjacent clusters is greater than 1200 kHz or an interval between two adjacent synchronization rasters included in a cluster is less than 50 kHz.
13 . The terminal of claim 8 , wherein in case that an SCS of the SSB is 15 kHz and a frequency band for the initial access is lower than 3000 MHz, a maximum value of the first parameter is less than 2499.
14 . The terminal of claim 8 , wherein in case that an SCS of the SSB is 15 kHz and a frequency band for the initial access is lower than 3000 MHz, a number of synchronization rasters included in a cluster is less than 3.
15 . The terminal of claim 8 , wherein an interval between two adjacent synchronization rasters included in a cluster is determined based on an altitude of the satellite.