Method for handling of DRX timers for multiple repetition transmission in wireless communication system and a device therefor

1. A method for a User Equipment (UE) operating in a wireless communication system, the method comprising:

monitoring a Physical Downlink Control Channel (PDCCH) during a first active time when Discontinuous Reception (DRX) is configured;

during the monitoring, receiving multiple repetitions of a PDCCH in a first plurality of subframes;

receiving multiple repetitions of Physical Downlink Shared Channel (PDSCH) corresponding to the PDCCH in a second plurality of subframes;

transmitting a single NACK in response to the multiple repetitions of PDSCH; and

starting a Hybrid ARQ (HARQ) Round Trip Time (RTT) Timer in a subframe containing a last repetition of the multiple repetitions of the PDSCH,

wherein the HARQ RTT Timer specifies a minimum amount of subframes before a PDCCH for a downlink HARQ retransmission is expected by the UE in response to the transmitted single NACK.

2. The method according to claim 1 , further comprising:

if the PDCCH for the downlink HARQ retransmission is received before the HARQ RTT Timer expires, receiving a PDSCH corresponding to the PDCCH for the downlink HARQ retransmission.

3. The method according to claim 1 , further comprising:

if the PDCCH for downlink HARQ retransmission is not received before the timer expires, monitoring the PDCCH during a second active time when the Discontinuous Reception (DRX) is configured.

4. The method according to claim 1 , further comprising:

stopping a DRX_retransmission timer in the subframe containing the last repetition of the multiple repetitions of the PDSCH, the DRX_retransmission timer corresponding to the first active time when the DRX is configured.

5. A User Equipment (UE) for operating in a wireless communication system, the UE comprising:

a Radio Frequency (RF) module; and

a processor operably coupled with the RF module and configured to:

monitor a Physical Downlink Control Channel (PDCCH) during a first active time when Discontinuous Reception (DRX) is configured,

during the monitoring, receive multiple repetitions of a PDCCH in a first plurality of subframes,

receive multiple repetitions of Physical Downlink Shared Channel (PDSCH) corresponding to the PDCCH in a second plurality of subframes,

transmit a single NACK in response to the multiple repetitions of PDSCH, and

start a Hybrid ARQ (HARD) Round Trip Time (RTT) Timer in a subframe containing a last repetition of the multiple repetitions of the PDSCH,

wherein the HARQ RTT Timer specifies a minimum amount of subframes before a PDCCH for a downlink HARQ retransmission is expected by the UE in response to the transmitted single NACK.

6. The UE according to claim 5 , wherein, if the PDCCH for the downlink HARQ retransmission is received before the HARQ RTT Timer expires, the processor is further configured to receive a PDSCH corresponding to the PDCCH for the downlink HARQ retransmission.

7. The UE according to claim 5 , wherein, if the PDCCH for downlink HARQ retransmission is not received before the timer expires, the processor is further configured to monitor the PDCCH during a second active time when the Discontinuous Reception (DRX) is configured.

8. The UE according to claim 5 , wherein the processor is further configured to:

stop a DRX_retransmission timer in the subframe containing the last repetition of the multiple repetitions of the PDSCH, the DRX_retransmission timer corresponding to the first active time when the DRX is configured.