METHOD AND APPARATUS FOR PERFORMING RANDOM ACCESS USING MULTIPLE PRACH OCCASIONS

1 .- 13 . (canceled)

14 . A User Equipment (UE) for radio communication, comprising:

a transmitter;

a receiver; and

a processor;

wherein the transmitter, the receiver, and the processor are configured to:

transmit a Random Access Preamble on a plurality of physical random access channel (PRACH) occasions, including a reference PRACH occasion, wherein each of the plurality of PRACH occasions is reserved for one transmission of the Random Access Preamble; and

monitor a physical downlink control channel (PDCCH) for a random access response identified by a radio network temporary identifier (RNTI), wherein the RNTI is a random access RNTI (RA-RNTI) that depends on only the reference PRACH occasion.

15 . The UE of claim 14 , wherein a reference downlink reference signal (RS) resource is used to determine the reference PRACH occasion; the reference downlink RS resource is a downlink RS resource in a downlink RS resource set, and the downlink RS resource set comprises at least two downlink RS resources; and the plurality of PRACH occasions are associated with at least one downlink RS resource in the downlink RS resource set.

16 . The UE of claim 15 , wherein the receiver is further configured to:

receive a radio resource control (RRC) message indicating the reference downlink RS resource in the downlink RS resource set.

17 . The UE of claim 15 , wherein the reference PRACH occasion is an earliest PRACH occasion among the plurality of PRACH occasions in a time domain.

18 . The UE of claim 15 , wherein the reference downlink RS resource is used to determine a given PRACH occasion associated with a given downlink RS resource, the given downlink RS resource being different from the reference downlink RS resource, and the given PRACH occasion being different from the reference PRACH occasion.

19 . The UE of claim 15 , wherein the downlink RS resource set is a subset of a target downlink RS resource set.

20 . The UE of claim 14 , wherein the PDCCH that schedules the random access response is scrambled with the RA-RNTI.

21 . The UE of claim 14 , wherein the RA-RNTI is computed as, RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id, where s_id is an index of a first OFDM symbol of the reference PRACH occasion, t_id is an index of a first slot of the reference PRACH occasion in a system frame, f_id is an index of the reference PRACH occasion in a frequency domain, and ul_carrier_id indicates an uplink carrier used for the transmission of the Random Access Preamble.

22 . The UE of claim 14 , wherein monitoring the PDCCH is performed in a ra-ResponseWindow, and a start moment of the ra-ResponseWindow is related to an end moment of the reference PRACH occasion.

23 . The UE of claim 14 , wherein the plurality of PRACH occasions correspond to a PRACH repetition for one random access attempt, the PRACH repetition including Msg1 repetition.

24 . A method performed by a User Equipment (UE) for radio communication, the method comprising:

transmitting a Random Access Preamble on a plurality of physical random access channel (PRACH) occasions, including a reference PRACH occasion, wherein each of the plurality of PRACH occasions is reserved for one transmission of the Random Access Preamble; and

monitoring a physical downlink control channel (PDCCH) for a random access response identified by a radio network temporary identifier (RNTI), wherein the RNTI is a random access RNTI (RA-RNTI) that depends on only the reference PRACH occasion.

25 . The method of claim 24 , wherein a reference downlink reference signal (RS) resource is used to determine the reference PRACH occasion; the reference downlink RS resource is a downlink RS resource in a downlink RS resource set, and the downlink RS resource set comprises at least two downlink RS resources; and the plurality of PRACH occasions are associated with at least one downlink RS resource in the downlink RS resource set.

26 . The method of claim 25 , further comprising:

receiving a radio resource control (RRC) message indicating the reference downlink RS resource in the downlink RS resource set.

27 . The method of claim 25 , wherein the reference PRACH occasion is an earliest PRACH occasion among the plurality of PRACH occasions in a time domain.

28 . The method of claim 25 , wherein the reference downlink RS resource is used to determine a given PRACH occasion associated with a given downlink RS resource, the given downlink RS resource being different from the reference downlink RS resource, and the given PRACH occasion being different from the reference PRACH occasion.

29 . The method of claim 25 , wherein the downlink RS resource set is a subset of a target downlink RS resource set.

30 . The method of claim 24 , wherein the PDCCH that schedules the random access response is scrambled with the RA-RNTI.

31 . The method of claim 24 , wherein the RA-RNTI is computed as, RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id, where s_id is an index of a first OFDM symbol of the reference PRACH occasion, t_id is an index of a first slot of the reference PRACH occasion in a system frame, f_id is an index of the reference PRACH occasion in a frequency domain, and ul_carrier_id indicates an uplink carrier used for the transmission of the Random Access Preamble.

32 . The method of claim 24 , wherein monitoring the PDCCH is performed in a ra-ResponseWindow, and a start moment of the ra-ResponseWindow is related to an end moment of the reference PRACH occasion.

33 . The method of claim 24 , wherein the plurality of PRACH occasions correspond to a PRACH repetition for one random access attempt, the PRACH repetition including Msg1 repetition.