Method for transmitting and receiving signals in wireless communication system, and device therefor

1. A method of transmitting downlink quality information during a random access procedure to a base station (BS) by a user equipment (UE) in a wireless communication system, the method comprising:

transmitting a first message (Msg1) for the random access procedure, the Msg1 including a random access preamble to the BS;

receiving a second message (Msg2) for the random access procedure, the Msg2 including a random access response from the BS; and

transmitting a third message (Msg3) for the random access procedure to the BS through a physical uplink shared channel (PUSCH) based on the random access response,

wherein the Msg3 for the random access procedure includes a downlink channel quality report (DCQR) that is measured by the UE while performing the random access procedure in a radio resource control (RRC) idle state,

wherein, in a frequency domain, the DCQR is measured in a frequency band where the random access response is received,

wherein, in a time domain, the DCQR is measured for a duration which starts from a beginning of the random access response, and an end of the duration is related to a transmission timing of the Msg3, and

wherein the measured DCQR is related to a physical downlink control channel (PDCCH) repetition level or a PDCCH aggregation level.

2. The method according to claim 1 , wherein the PDCCH repetition level is a repetition number required for PDCCH decoding in reference resources for downlink quality measurement.

3. The method according to claim 2 , wherein the reference resources for downlink quality measurement include a group of physical resource blocks (PRBs) for all narrowbands related to the repetition number.

4. The method according to claim 2 , wherein the Msg3 includes information about narrowband downlink quality of a preferred narrowband and information about a position of the preferred narrowband.

5. The method according to claim 4 , wherein the preferred narrowband is selected from among the reference resources for downlink quality measurement.

6. The method according to claim 1 , wherein the PDCCH is a machine type communication (MTC) PDCCH.

7. An apparatus for wireless communication, the apparatus comprising:

a memory including instructions; and

a processor operatively coupled to the memory,

wherein the processor is configured to perform specific operations by executing the instructions,

wherein the specific operations include:

transmitting a first message (Msg1) for a random access procedure, the Msg1 including a random access preamble to a base station (BS);

receiving a second message (Msg2) for the random access procedure, the Msg2 including a random access response from the BS; and

transmitting a third message (Msg3) for the random access procedure to the BS through a physical uplink shared channel (PUSCH) based on the random access response,

wherein the Msg3 for the random access procedure includes a downlink channel quality report (DCQR) that is measured by the processor while performing the random access procedure in a radio resource control (RRC) idle state,

wherein, in a frequency domain, the DCQR is measured in a frequency band where the random access response is received,

wherein, in a time domain, the DCQR is measured for a duration which starts from a beginning of the random access response, and an end of the duration is related to a transmission timing of the Msg3, and

wherein the measured DCQR is related to a physical downlink control channel (PDCCH) repetition level or a PDCCH aggregation level.

8. The apparatus of claim 7 , further comprising:

a transceiver configured to transmit or receive a radio signal under control of the processor,

wherein the apparatus is a user equipment (UE) configured to operate in a wireless communication system.

9. A non-transitory medium readable by a processor and storing instructions that cause the processor to perform operations for transmitting downlink quality information during a random access procedure to a base station (BS) by a user equipment (UE) in a wireless communication system, the operations comprising:

transmitting a first message (Msg1) for the random access procedure, the Msg1 including a random access preamble to the BS;

receiving a second message (Msg2) for the random access procedure, the Msg2 including a random access response from the BS; and

transmitting a third message (Msg3) for the random access procedure to the BS through a physical uplink shared channel (PUSCH) based on the random access response,

wherein the Msg3 for the random access procedure includes a downlink channel quality report (DCQR) that is measured by the UE while performing the random access procedure in a radio resource control (RRC) idle state,

wherein, in a frequency domain, the DCQR is measured in a frequency band where the random access response is received,

wherein, in a time domain, the DCQR is measured for a duration which starts from a beginning of the random access response, and an end of the duration is related to a transmission timing of the Msg3, and

wherein the measured DCQR is related to a physical downlink control channel (PDCCH) repetition level or a PDCCH aggregation level.

10. A method of receiving downlink quality information during a random access procedure by a base station (BS) in a wireless communication system, the method comprising:

receiving, from a user equipment (UE) in a radio resource control (RRC) idle state, a first message (Msg1) for the random access procedure, the Msg1 including a random access preamble;

transmitting, to the UE in the RRC idle state, a second message (Msg2) for the random access procedure, the Msg2 including a random access response; and

receiving, from the UE in the RRC idle state, a third message (Msg3) for the random access procedure through a physical uplink shared channel (PUSCH) based on the random access response,

wherein the Msg3 for the random access procedure includes a downlink channel quality report (DCQR) that is measured during the random access procedure,

wherein, in a frequency domain, the DCQR is measured in a frequency band where the random access response is transmitted,

wherein, in a time domain, the DCQR is measured for a duration which starts from a beginning of the random access response, and an end of the duration is related to a reception timing of the Msg3, and

wherein the measured DCQR is related to a physical downlink control channel (PDCCH) repetition level or a PDCCH aggregation level.

11. A base station (BS) comprising:

a memory including instructions; and

a processor operatively coupled to the memory,

wherein the processor is configured to perform specific operations by executing the instructions,

wherein the specific operations include:

receiving, from a user equipment (UE) in a radio resource control (RRC) idle state, a first message (Msg1) for a random access procedure, the Msg1 including a random access preamble;

transmitting, to the UE in the RRC idle state, a second message (Msg2) for the random access procedure, the Msg2 including a random access response; and

receiving, from the UE in the RRC idle state, a third message (Msg3) for the random access procedure through a physical uplink shared channel (PUSCH) based on the random access response,

wherein the Msg3 for the random access procedure includes a downlink channel quality report (DCQR) that is measured during the random access procedure,

wherein, in a frequency domain, the DCQR is measured in a frequency band where the random access response is transmitted,

wherein, in a time domain, the DCQR is measured for a duration which starts from a beginning of the random access response, and an end of the duration is related to a reception timing of the Msg3, and

wherein the measured DCQR is related to a physical downlink control channel (PDCCH) repetition level or a PDCCH aggregation level.