Initial access with multiple PRACH transmissions

A base station (BS) comprising:

• a transceiver configured to:
• transmit a system information block (SIB) including (i) information associated with random access resources, (ii) at least one reference signal received power (RSRP) threshold, and (iii) information on random access response (RAR) window, wherein the random access resources include first random access resources associated with physical random access channel (PRACH) repetitions,
• receive PRACH transmission for a number of PRACH repetitions based on random access resources among the first random access resources, and
• transmit a downlink control information (DCI) format 1_0 on a physical downlink control channel (PDCCH) while the RAR window is running;
• and
• a processor operably coupled to the transceiver,
• wherein the number of PRACH preamble repetitions is based on the at least one RSRP threshold and an RSRP measurement of a downlink reference signal,
• wherein the at least one RSRP threshold corresponds to at least one number for the PRACH repetitions,
• wherein the random access resources are for the number of PRACH repetitions and associated with a synchronization signal and physical broadcast channel (SS/PBCH) block index of a transmitted SS/PBCH block,
• wherein a cyclic redundancy check (CRC) of the DCI format 1_0 is scrambled by a random access radio network temporary identifier (RA-RNTI), and
• wherein the RA-RNTI is associated with a last random access resource in the random access resources.

A method comprising:

• receiving a system information block (SIB) including (i) information associated with random access resources, (ii) at least one reference signal received power (RSRP) threshold, and (iii) information on random access response (RAR) window, wherein the random access resources include first random access resources associated with physical random access channel (PRACH) repetitions;
• determining, among at least one number for the PRACH repetitions, a number of the PRACH repetitions based on the at least one RSRP threshold and an RSRP measurement of a downlink reference signal, wherein the at least one RSRP threshold corresponds to the at least one number;
• determining random access resources for the determined number of PRACH repetitions among the first random access resources, wherein the determined random access resources are associated with a synchronization signal and physical broadcast channel (SS/PBCH) block index of a received SS/PBCH block;
• and
• performing PRACH transmission for the number of PRACH repetitions based on the determined random access resources;
• and
• monitoring a downlink control information (DCI) format 1_0 on a physical downlink control channel (PDCCH) while the RAR window is running,
• wherein a cyclic redundancy check (CRC) of the DCI format 1_0 is scrambled by a random access radio network temporary identifier (RA-RNTI),
• wherein the RA-RNTI is associated with a last random access resource in the determined random access resources,
• wherein the determined random access resources are consecutive in time and correspond to same frequency resources,
• wherein the SS/PBCH block index is associated with a PRACH preamble for the PRACH repetitions,
• wherein the determined random access resources are consecutive in time and correspond to same frequency resources, and
• wherein the SS/PBCH block index is associated with a PRACH preamble for the PRACH repetitions.