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

Claim 10:
11. A terminal in a wireless communication system, the terminal comprising:
a transceiver configured to transmit or receive a signal; and
a controller coupled with the transceiver and configured to:
receive, from a base station, a message including a first physical random access channel (PRACH) configuration index for a 4-step random access,
in case that a 2-step random access is initiated and the message does not include a second PRACH configuration index for the 2-step random access, identify at least one random access preamble for the 2-step random access 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,
identify at least one PRACH occasion for the 2-step random access based on the first PRACH configuration index for the 4-step random access,
identify an SSB,
identify a random access preamble for the 2-step random access from the at least one random access preamble corresponding to the SSB,
identify a PRACH occasion for the 2-step random access from the at least one PRACH occasion corresponding to the SSB, and
transmit, to the base station, a message A (MSG A) including the random access preamble using the PRACH occasion,

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, and
wherein N SSBs per PRACH occasion are numbered sequentially from zero to N−1 in ascending order of an SSB index.