Method for selecting RACH freamble sequence for high-speed mode and low-speed mode

A method for a base station (BS) to receive a random access channel (RACH) preamble sequence from user equipment (UE), the method comprising:

• transmitting, to the UE, signaling information for a random access to the BS;
• and
• receiving, from the UE, the RACH preamble sequence generated based on the signaling information,
• wherein the signaling information is associated with a first parameter value for an unrestricted cyclic shift set and a second parameter value for a restricted cyclic shift set, and
• wherein the RACH preamble sequence is generated using the first parameter value when the UE is in a low-mobility mode and the RACH preamble sequence is generated using the second parameter value when the UE is in a high-mobility mode.

User equipment (UE) for transmitting a random access channel (RACH) preamble sequence to a base station (BS), the UE comprising:

• a receiver configured to receive, from the BS, signaling information for a random access to the BS;
• and
• a transmitter configured to transmit, to the BS, the RACH preamble sequence generated based on the signaling information,
• wherein the signaling information is associated with a first parameter value for an unrestricted cyclic shift set and a second parameter value for a restricted cyclic shift set, and
• wherein the RACH preamble sequence is generated using the first parameter value when the UE is in a low-mobility mode and the RACH preamble sequence is generated using the second parameter value when the UE is in a high-mobility mode.

A base station (BS) for receiving a random access channel (RACH) preamble sequence from a user equipment (UE), the base station comprising:

• a transmitter configured to transmit, to the UE, signaling information for a random access to the BS;
• and
• a receiver configured to receive, from the UE, the RACH preamble sequence generated based on the signaling information,
• wherein the signaling information is associated with a first parameter value for an unrestricted cyclic shift set and a second parameter value for a restricted cyclic shift set, and
• wherein the RACH preamble sequence is generated using the first parameter value when the UE is in a low-mobility mode and the RACH preamble sequence is generated using the second parameter value when the UE is in a high-mobility mode.