Uplink timing and frequency synchronization

A base station (BS), comprising:

• a processor configured to identify satellite ephemeris information of a communication satellite associated with the BS, a common timing advance (TA), and a compensated frequency offset (FO);
• a transceiver operably connected to the processor, the transceiver configured to:
• transmit information indicating the satellite ephemeris information, the common TA, and the compensated FO, and
• receive, from a user equipment (UE), a physical random access channel (PRACH),
• wherein the processor is further configured to determine a TA and a FO for the UE based on the received PRACH, and
• wherein the transceiver is further configured to transmit a random access response (RAR) indicating the determined TA and FO.

A method for operating a user equipment (UE), the method comprising:

• receiving, from a base station (BS), information indicating satellite ephemeris information of a communication satellite associated with the BS, a common timing advance (TA), and a compensated frequency offset (FO);
• transmitting a physical random access channel (PRACH) based on the common TA and the compensated FO;
• receiving a random access response (RAR) indicating a UE-specific TA and FO;
• and
• for transmission of an uplink (UL) channel, adjusting a TA and pre-compensating a FO based on the UE-specific TA and FO, respectively.