Method for mitigating inter cell interference and device therefor
The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device therefor, wherein the method comprises the steps of: receiving a PDCCH signal that contains scheduling information from a base station on a first subframe; receiving a PDSCH signal corresponding to said PDCCH signal from said base station on a second subframe; and decoding said PDSCH signal, wherein an interval between said first subframe and said second subframe is varied.
1. A method for receiving a downlink signal by a user equipment (UE) in a wireless communication, the method comprising:
receiving a Radio Resource Control (RRC) message including a Physical Downlink Shared Channel (PDSCH) starting point information;
receiving a Physical Downlink Control Channel (PDCCH) signal including downlink control information (DCI) in a first time resource;
receiving the PDSCH signal scheduled by the DCI in a second time resource after the first time resource;
decoding the PDSCH signal,
wherein a time interval between the first time resource in which the PDCCH signal is received and the second time resource in which the PDSCH signal is received varies according to a time resource indication field included in the DCI, and
wherein the UE identifies the second time resource by using information on the time interval that is obtained from the time resource indication field in the DCI; and
determining a starting orthogonal frequency division multiplexing (OFDM) symbol of the PDSCH, from amongst a plurality of OFDM symbols, in the second time resource based on the PDSCH starting point information.
2. The method according to claim 1 , wherein each of the first time resource and the second time resource corresponds to 14 orthogonal frequency division multiplexing (OFDM) symbols.
3. The method according to claim 2 , wherein each OFDM symbol is configured with a normal cyclic prefix (CP).
4. The method according to claim 3 , wherein each of the first time resource and the second time resource corresponds to 12 OFDM symbols each configured with an extended CP.
5. The method according to claim 1 ,
wherein the second time resource is offset from the first time resource by N time resources and
wherein the time resource indication field indicates the offset ‘N’.
6. The method according to claim 1 , wherein the time resource indication field indicates the second time resource in which the PDSCH signal is actually allocated among a plurality of time resources in which the PDSCH signal can be allocated.
7. The method according to claim 6 , further comprising:
receiving, through the RRC message, information on the time resources in which the PDSCH signal can be allocated.
8. The method according to claim 1 , wherein a number of bits of the time resource indication field is determined through the RRC message.
9. The method according to claim 1 , further comprising:
transmitting, through a physical uplink control channel (PUCCH) signal on a third time resource, acknowledgement (ACK)/negative ACK (NACK) according to a result of decoding the PDSCH signal,
wherein the third time resource is determined based on the second time resource in which the PDSCH signal is received, and not the first time resource in which the PDCCH signal is received.
10. The method according to claim 9 , wherein the ACK/NACK transmission corresponds to an asynchronous hybrid automatic repeat request (HARQ) operation.
11. The method of claim 1 further comprising:
receiving a second control channel comprising information, based on which, the starting OFDM symbol of the PDSCH in the second time resource is determined.
12. A method of transmitting a downlink signal by a base station (BS), the method comprising:
transmitting a Radio Resource Control (RRC) message including a Physical Downlink Shared Channel (PDSCH) starting point information;
transmitting a physical downlink control channel (PDCCH) signal including downlink control information (DCI) in a first time resource; and
transmitting the PDSCH signal scheduled by the DCI in a second time resource after the first time resource,
wherein a time interval between the first time resource in which the PDCCH signal is transmitted and the second time resource in which the PDSCH signal is transmitted varies according to a determination by the BS,
wherein the BS informs the UE of the time interval using a time resource indication field included in the DCI; and
wherein a starting orthogonal frequency division multiplexing (OFDM) symbol of the PDSCH is determined, from amongst a plurality of OFDM symbols, in the second time resource based on the PDSCH starting point information.
13. The method according to claim 12 , wherein each of the first time resource and the second time resource corresponds to 14 orthogonal frequency division multiplexing (OFDM) symbols.
14. The method according to claim 12 ,
wherein the second time resource is offset from the first time resource by N time resources and
wherein the time resource indication field indicates the offset ‘N’.
15. The method according to claim 12 , wherein the time resource indication field indicates the second time resource in which the PDSCH signal is actually allocated among a plurality of time resources in which the PDSCH signal can be allocated.
16. The method according to claim 15 , further comprising:
transmitting, through the RRC message, information on the time resources in which the PDSCH signal can be allocated.
17. The method according to claim 12 , further comprising:
transmitting, through the RRC message, information on a number of bits of the time resource indication field.
18. The method according to claim 12 , further comprising:
receiving, through a physical uplink control channel (PUCCH) signal on a third time resource, acknowledgement (ACK)/negative-ACK(NACK) for the PDSCH signal,
wherein the third time resource is determined based on the second time resource in which the PDSCH signal is transmitted, and not the first time resource in which the PDCCH signal is transmitted, and
wherein the ACK/NACK reception corresponds to an asynchronous hybrid automatic repeat request (HARQ) operation.
19. The method of claim 12 further comprising:
transmitting a second control channel to the UE comprising the additional information, based on which, the starting OFDM symbol of the PDSCH in the second time resource is determined.
20. A user equipment (UE) comprising:
a receiver; and
a processor to control the receiver:
to receive a Radio Resource Control (RRC) message including a Physical Downlink Shared Channel (PDSCH) starting point information;
to receive a physical downlink control channel (PDCCH) signal including downlink control information (DCI) in a first time resource, and
to receive the PDSCH signal scheduled by the DCI in a second time resource after the first time resource, and to decode the PDSCH signal,
wherein a time interval between the first time resource in which the PDCCH signal is received and the second time resource in which the PDSCH signal is received varies according to a time resource indication field included in the DCI,
wherein the processor identifies the second time resource by using information on the time interval that is obtained from the time resource indication field in the DCI, and
wherein the processor further determines a starting orthogonal frequency division multiplexing (OFDM) symbol of the PDSCH, from amongst a plurality of OFDM symbols, in the second time resource based on the PDSCH starting point information.
21. The UE of claim 20 , wherein the processor further controls the receiver to receive a second control channel that comprises information, based on which, the processor determines the starting OFDM symbol of the PDSCH in the second time resource.
22. A base station (BS) comprising:
a transmitter; and
a processor to control the transmitter:
to transmit a Radio Resource Control (RRC) message including a Physical Downlink Shared Channel (PDSCH) starting point information;
to transmit a physical downlink control channel (PDCCH) signal including downlink control information (DCI) in a first time resource, and
to transmit the PDSCH signal scheduled by the DCI in a second time resource after the first time resource,
wherein a time interval between the first time resource in which the PDCCH signal is transmitted and the second time resource in which the PDSCH signal is transmitted varies according to a determination by the BS,
wherein the processor informs the UE of the determined time interval using a time resource indication field included in the DCI, and
wherein a starting orthogonal frequency division multiplexing (OFDM) symbol of the PDSCH is determined, from amongst a plurality of OFDM symbols, in the second time resource based on the PDSCH starting point information.
23. The BS of claim 22 , wherein the processor further controls the transmitter to transmit a second control channel to the UE comprising the additional information, based on which, the starting OFDM symbol of the PDSCH in the second time resource is determined.