Method of performing random access procedure in wireless communication system
A method of performing random access procedure includes receiving information on a dedicated random access preamble, transmitting the dedicated random access preamble, and receiving a random access response comprising a random access preamble identifier corresponding to the dedicated random access preamble and a downlink radio resource assignment.
1. A method of performing a random access procedure in a wireless communication system, the method performed by a user equipment comprising:
receiving information regarding a dedicated random access preamble via a physical downlink control channel (PDCCH);
transmitting the dedicated random access preamble;
receiving a random access response via a physical downlink shared channel (PDSCH),
wherein the random access response includes a random access preamble identifier corresponding to the dedicated random access preamble and a downlink radio resource assignment, and
wherein the PDSCH is addressed by the PDCCH having a cyclic redundancy check (CRC) masked with a unique identifier; and
receiving downlink data using the downlink radio resource assignment via the PDSCH without monitoring an additional PDCCH.
2. The method of claim 1 , wherein the downlink radio resource assignment comprises a resource assignment configured to receive the downlink data and information regarding hybrid automatic repeat request (HARQ) feedback transmission for the downlink data.
3. The method of claim 2 , further comprising transmitting a HARQ feedback for the downlink data using the information regarding the HARQ feedback transmission.
4. The method of claim 1 , further comprising transmitting hybrid automatic repeat request (HARQ) feedback for the downlink data using information received from system information.
5. The method of claim 1 , further comprising transmitting hybrid automatic repeat request (HARQ) feedback for the downlink data using information received from a handover command message.
6. The method of claim 1 , wherein a time alignment timer that is configured to enable uplink transmission expires prior to receiving the information regarding the dedicated random access preamble.
7. The method of claim 1 , wherein the random access response further includes a time alignment value configured to adjust uplink time alignment.
8. The method of claim 1 , wherein:
the random access response is a medium access control (MAC) protocol data unit (PDU) that comprises a MAC header and at least one MAC random access response (RAR),
the MAC header comprises at least one MAC subheader,
the at least one MAC subheader corresponds to a MAC RAR and comprises the random access preamble identifier, and
the MAC RAR comprises the downlink radio resource assignment.
9. The method of claim 8 , wherein the MAC RAR further comprises a time alignment field and a downlink grant field configured to indicate the downlink radio resource assignment.
10. The method of claim 9 , further comprising:
performing discontinuous reception (DRX) after receiving the random access response; and
discontinuing performance of the DRX when the downlink data is received.
11. The method of claim 9 , wherein the time alignment field includes an uplink alignment value.
12. The method of claim 1 , wherein the PDCCH is further addressed by a random access-radio network temporary identifier(RA-RNTI).