Patent ID: 11882592
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 15:
16. A base station in a wireless communication system, the base station comprising:
a transceiver configured to transmit or receive a signal; and
a controller coupled with the transceiver and configured to:
transmit, to a terminal, a message including a first physical random access channel (PRACH) configuration index for a 4-step random access, and
receive, from the terminal, a message A (MSG A) of a 2-step random access using a PRACH occasion in case that the 2-step random access is initiated, the MSG A including a random access preamble for the 2-step random access,

wherein, in case that the message does not include a second PRACH configuration index for the 2-step random access, the random access preamble for the 2-step random access is based on a number N of synchronization signal blocks (SSBs) per PRACH occasion for the 4-step random access and a number of contention based preambles per SSB for the 2-step random access,
wherein, in case that the N is smaller than 1, contention based preambles with consecutive indexes associated with the SSB per valid PRACH occasion start from a preamble index R, the R being a number of contention based preambles per SSB for the 4-step random access,
wherein, in case that the N is larger than or equal to 1, the contention based preambles with consecutive indexes associated with an nth SSB per valid PRACH occasion start from a preamble index n*Npreambletotal/N+R, the n being an SSB index and the Npreambletotal being a total number of preambles for the 4-step random access,
wherein the PRACH occasion is based the first PRACH configuration index for the 4-step random access, and
wherein N SSBs per PRACH occasion are numbered sequentially from zero to N−1 in ascending order of an SSB index.