Method and user equipment for receiving downlink signals

1. A method for receiving, by a user equipment (UE), downlink signals in a wireless communication system, the method comprising:

receiving, by the UE, a physical downlink control channel (PDCCH) scheduling a transmission of a transport block (TB); and

starting a hybrid automatic repeat request (HARQ) round trip timer (RTT) for the data transmission,

wherein the HARQ RTT timer is set to a non-negative value associated with a radio network temporary identifier (RNTI) addressing the PDCCH,

wherein the non-negative value is a first value if the RNTI is a system information RNTI (SI-RNTI), paging RNTI (P-RNTI) or random access RNTI (RA-RNTI), and the non-negative value is a second value if the RNTI is a cell RNTI (C-RNTI),

wherein the first value is larger than the second value,

wherein the first value is associated with a normal processing time, and the second value is associated with a short processing time,

wherein the normal processing time and the short processing time are defined by a number of transmission time intervals (TTIs), and

wherein a length of the TTI is determined dynamically based on the TB.

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

starting, by the UE, a retransmission timer when the HARQ RTT expires; and

monitoring, by the UE, a PDCCH for retransmission of the data transmission while the retransmission timer is running.

3. A user equipment (UE) for receiving downlink signals in a wireless communication system, the UE comprising:

a transmitter and a receiver, and

a processor operatively coupled to the transmitter and receiver, the processor configured to:

control the receiver to receive a physical downlink control channel (PDCCH) scheduling a transmission of a transport block (TB); and

start a hybrid automatic repeat request (HARQ) round trip timer or (RTT) the data transmission,

wherein the HARQ RTT is set to a non-negative value associated with a radio network temporary identifier (RNTI) addressing the PDCCH,

wherein the non-negative value is a first value if the RNTI is a system information RNTI (SI-RNTI), paging RNTI (P-RNTI) or random access RNTI (RA-RNTI), and the non-negative value is a second value if the RNTI is other than the SI-RNTI, the P-RNTI or the RA-RNTI,

wherein the first value is larger than the second value,

wherein the first value is associated with a normal processing time, and the second value is associated with a short processing time,

wherein the normal processing time and the short processing time are defined by a number of transmission time intervals (TTIs), and

wherein a length of the TTI is determined dynamically based on the TB.

4. The UE according to claim 3 , wherein the processor is further configured to:

start a retransmission timer when the HARQ RTT expires; and

monitor a PDCCH for retransmission of the data transmission while the retransmission timer is running.