Methods, communication device and satellite transmitter for cell synchronization in non-geostationary orbit satellite mobile communication system

A communication device (202), the communication device (202) being configured for:

• receiving a partially pre-compensated synchronization signal block (SSB), (204) through a downlink (DL), beam (206) from a Non-Geostationary Orbit (NGSO) satellite transmitter (208), and
• achieving a cell synchronization with the NGSO satellite transmitter (208) using the partially pre-compensated SSB (204),
• wherein a central frequency of a primary synchronization signal (PSS), (210) and a central frequency of a secondary synchronization signal (SSS), (212) within the partially pre-compensated SSB (204) are pre-shifted by the NGSO satellite transmitter (208) with respect to a central frequency of the partially pre-compensated SSB (204) by an integer number of subcarriers for a partial pre-compensation of a Doppler shift related to a movement of the NGSO satellite transmitter (208) with respect to a coverage area of the DL beam (206) on Earth.

A satellite transmitter (208) being configured for:

• determining a value of a partial pre-compensation of a Doppler shift related to a movement of the satellite transmitter (208) with respect to a coverage area of a downlink (DL), beam (206) on Earth,
• pre-shifting a central frequency of a primary synchronization signal (PSS), (210) and a central frequency of a secondary synchronization signal (SSS), (212) within a synchronization signal block (SSB), with respect to a central frequency of the SSB by an integer number of subcarriers that corresponds to the determined value of the partial pre-compensation of the Doppler shift to obtain a partially pre-compensated SSB, (204) and transmitting the partially pre-compensated SSB (204) within the coverage area of the DL beam (206).