Method and apparatus for transmitting an uplink signal in a wireless communication system

A terminal, in a wireless communication system, the terminal comprising:

• a memory;
• a transceiver;
• and
• at least one processor operably connected to the transceiver, the at least one processor configured to:
• control the transceiver to receive, from a base station, an uplink configuration information associated with a first message for a 2-step random access, wherein in case that the terminal is in an Radio Resource Control (RRC) connected state, the uplink configuration information is included in terminal specific RRC information and in case that the terminal is in an RRC Idle state or RRC Inactive state, the uplink configuration information is included in system information message
• control the transceiver to transmit the first message comprising a Physical Random Access Channel (PRACH) preamble and a Physical Uplink Shared Channel (PUSCH) based on the uplink configuration information;
• control the transceiver to receive a feedback message comprising a Random Access Response (RAR) as a response to the transmitted first message,
• identify whether the RAR is a fallback RAR or a success RAR,
• in case that the RAR is the fallback RAR:
• control the transceiver to determine a transport block size for a PUSCH scheduled by the fallback RAR, wherein the transport block size for the PUSCH scheduled by the fallback RAR is same as a transport block size of the PUSCH included in the first message,
• control the transceiver to determine a modulation and coding scheme for the PUSCH scheduled by the fallback RAR, and
• control the transceiver to transmit the PUSCH scheduled by the fallback RAR based on the determined transport block size and the determined modulation and coding scheme;
• and
• in case that the RAR is the success RAR:
• control the transceiver to transmit information related to Hybrid Automatic Repeat request-Acknowledgment, HARQ-ACK, feedback based on a Physical Uplink Control Channel (PUCCH) resource indicator included in the success RAR.

A method, performed by a base station (BS), of receiving an uplink signal in a wireless communication system, the method comprising:

• transmitting, to a terminal, an uplink configuration information associated with a first message for a 2-step random access, wherein in case that the terminal is in an Radio Resource Control (RRC) connected state, the uplink configuration information is included in terminal specific RRC information and in case that the terminal is in an RRC Idle state or RRC Inactive state, the uplink configuration information is included in system information;
• receiving, from the terminal, the first message based on the first uplink configuration information;
• identifying whether the first message comprises a Physical Random Access Channel (PRACH) preamble or a Physical Uplink Shared Channel (PUSCH);
• in case that the first message comprises the PRACH preamble and does not comprise the PUSCH:
• transmitting, to the terminal, a feedback message comprising a fallback Random Access Response (RAR);
• and
• receiving a PUSCH based on a second transport block size and a modulation and coding scheme determined by a terminal,
• wherein the second transport block size is the same as a first transport block size of the PUSCH included in the first message;
• and
• in case that the first message comprises the PRACH preamble and the PUSCH:
• transmitting, to the terminal, a feedback message comprising a success RAR;
• and
• receiving, from the terminal, Hybrid Automatic Repeat reQuest-Acknowledgment (HARQ-ACK) feedback according to a Physical Uplink Control Channel (PUCCH) resource indicator included in the success RAR.

A base station (BS) in a wireless communication system, the base station comprising:

• a transceiver;
• and
• at least one processor operably connected to the transceiver, the at least one processor configured to:
• control the transceiver to transmit, to a terminal, an uplink configuration information associated with a first message for a 2-step random access, wherein in case that the terminal is in an Radio Resource Control (RRC) connected state, the uplink configuration information is included in terminal specific RRC information and in case that the terminal is in an RRC Idle state or RRC Inactive state, the uplink configuration information is included in system information,
• control the transceiver to receive, from the terminal, the first message based on the uplink configuration information,
• identify whether the first message comprises a Physical Random Access Channel (PRACH) preamble or Physical Uplink Shared Channel (PUSCH),
• in case that the first message comprises the PRACH preamble and does not comprise the PUSCH,
• transmit, to the terminal, a fallback Random Access Response (RAR);
• and
• receive a PUSCH based on a second transport block size and a modulation and coding scheme determined by a terminal,
• wherein the second transport block size is the same as a first transport block size of the PUSCH included in the first message;
• and
• in case that the first message comprises the PRACH preamble and the PUSCH:
• transmit, to the terminal, a feedback message comprising a success RAR;
• and
• receive, from the terminal, Hybrid Automatic Repeat reQuest-Acknowledgment (HARQ-ACK) feedback according to a Physical Uplink Control Channel PUCCH) resource indicator included in the success RAR.