Method and apparatus for reducing power consumption of terminal in wireless communication system

1. A terminal capable of power saving in a wireless communication system, comprising:

a transceiver; and

at least one processor coupled with the transceiver and configured to:

identify a configuration for reporting at least one of:

preference information associated with a maximum bandwidth for power saving, or

preference information associated with a maximum value of a number of layers for power saving,

transmit, to a base station (BS), based on the identified configuration for the reporting, a power saving request message including the at least one of the preference information associated with the maximum bandwidth for power saving, or the preference information associated with the maximum value of the number of layers for power saving,

receive, from the BS, configuration information including a maximum number of layers to be used for Physical Downlink Shared Channel (PDSCH),

based on the configuration information, receive, from the BS, the PDSCH using the maximum number of layers or less than the maximum number of layers, and

deactivate some of antennas based on a time gap between a time at which the configuration information is received and a starting time at which the PDSCH is received.

2. The terminal of claim 1 , wherein the at least one processor is further configured to:

transmit, to the BS, power saving capability information including at least one of capability information to report the preference information associated with the maximum bandwidth for power saving, or capability information to report the preference information associated with the maximum value of the number of layers for power saving.

3. The terminal of claim 2 , wherein the power saving capability information further includes an indication for a maximum number of Physical Downlink Control Channel (PDCCH) candidates.

4. The terminal of claim 1 ,

wherein the power saving request message is transmitted via Remote Radio Control (RRC) signaling; and

wherein the configuration information including the maximum number of layers to be used for PDSCH is transmitted via higher layer signaling.

5. The terminal of claim 1 , wherein the at least one processor is further configured to:

receive, from the BS, configuration information associated with the maximum number of layers to be used for Physical Uplink Shared Channel (PUSCH); and

transmit, to the BS, the PUSCH using equal to or less than the maximum number of layers to be used for PUSCH based on the configuration information associated with the maximum number of layers to be used for PUSCH.

6. The terminal of claim 1 , wherein the power saving request message further includes at least one of a minimum value of a PDCCH monitoring periodicity, a maximum number of Demodulation Reference Signal (DMRS) ports, or a maximum bandwidth of a bandwidth part.

7. The terminal of claim 1 , wherein the at least one processor is further configured to:

identify the time gap between the time at which the configuration information including the maximum number of layers to be used for PDSCH is received and the starting time at which the PDSCH is received,

determine whether the time gap is greater than a transition time required to deactivate some of the antennas based on the maximum number of layers to be used for PDSCH,

when the time gap is greater than the transition time, deactivate some of the antennas based on the maximum number of layers to be used for PDSCH and receive the PDSCH using antennas except for the deactivated antennas, and

when the time gap is smaller than the transition time, receive the PDSCH using all of the antennas.

8. A base station (BS) for power saving in a wireless communication system, comprising:

a transceiver; and

at least one processor coupled with the transceiver and configured to:

in case that a configuration for reporting at least one preference information is identified at a terminal, receive, from the terminal, a power saving request message including at least one of:

preference information associated with a maximum bandwidth for power saving, or

preference information associated with a maximum value of a number of layers for power saving,

transmit, to the terminal, configuration information including a maximum number of layers to be used for Physical Downlink Shared Channel (PDSCH),

based on the configuration information, transmit, to the terminal, the PDSCH using the maximum number of layers or less than the maximum number of layers,

wherein some of antennas of the terminal are deactivated based on a time gap between a time at which the configuration information is received at the terminal and a starting time at which the PDSCH is received at the terminal.

9. The BS of claim 8 , wherein the at least one processor is further configured to:

receive, from the terminal, power saving capability information including at least one of capability information to report the preference information associated with the maximum bandwidth for power saving or capability information to report the preference information associated with the maximum value of the number of layers for power saving.

10. The BS of claim 9 , wherein the power saving capability information further includes an indication for a maximum number of Physical Downlink Control Channel (PDCCH) candidates.

11. The BS of claim 8 ,

wherein the power saving request message is transmitted via Remote Radio Control (RRC) signaling; and

wherein the configuration information including the maximum number of layers to be used for PDSCH is transmitted via higher layer signaling.

12. The BS of claim 8 , wherein the at least one processor is further configured to:

transmit, to the terminal, configuration information associated with the maximum number of layers to be used for Physical Uplink Shared Channel (PUSCH) based on the power saving request message, and

receive, from the terminal, the PUSCH using equal to or less than the maximum number of layers to be used for PUSCH based on the configuration information associated with the maximum number of layers to be used for PUSCH.

13. The BS of claim 8 , wherein the power saving request message further includes at least one of a minimum value of a PDCCH monitoring periodicity, a maximum number of Demodulation Reference Signal (DMRS) ports, or a maximum bandwidth of a bandwidth part.

14. A method performed by a terminal capable of power saving in a wireless communication system, comprising:

identifying a configuration for reporting at least one of: preference information associated with a maximum bandwidth for power saving or preference information associated with a maximum value of a number of layer for power saving;

transmitting, to a base station (BS) based on the identified configuration for the reporting, a power saving request message including the at least one of: the preference information associated with the maximum bandwidth for power saving or the preference information associated with the maximum value of the number of layers for power saving;

receiving, from the BS, configuration information including a maximum number of layers to be used for Physical Downlink Shared Channel (PDSCH);

based on the configuration information, receiving, from the BS, the PDSCH using the maximum number of layers or less than the maximum number of layers, and

deactivating some of antennas based on a time gap between a time at which the configuration information is received and a starting time at which the PDSCH is received.

15. The method of claim 14 , further comprising:

transmitting, to the BS, power saving capability information including at least one of capability information to report the preference information associated with the maximum bandwidth for power saving or capability information to report the preference information associated with the maximum value of the number of layers for power saving.

16. The method of claim 14 ,

wherein the power saving capability information further includes an indication for a maximum number of Physical Downlink Control Channel (PDCCH) candidates.

17. The method of claim 14 ,

wherein the power saving request message is transmitted via Remote Radio Control (RRC) signaling; and

wherein the configuration information including the maximum number of layers to be used for PDSCH is transmitted via higher layer signaling.

18. The method of claim 14 , further comprising:

receiving, from the BS, configuration information associated with the maximum number of layers to be used for Physical Uplink Shared Channel (PUSCH); and

transmitting, to the BS, the PUSCH using equal to or less than the maximum number of layers to be used for PUSCH based on the configuration information associated with the maximum number of layers to be used for PUSCH.

19. The method of claim 14 ,

wherein the power saving request message further includes at least one of a minimum value of a PDCCH monitoring periodicity, a maximum number of Demodulation Reference Signal (DMRS) ports, or a maximum bandwidth of a bandwidth part.

20. The method of claim 14 , further comprising:

identifying the time gap between the time at which the configuration information including the maximum number of layers to be used for PDSCH is received and the starting time at which the PDSCH is received;

determining whether the time gap is greater than a transition time required to deactivate some of the antennas based on the maximum number of layers to be used for PDSCH;

when the time gap is greater than the transition time, deactivating some of the antennas based on the maximum number of layers to be used for PDSCH and receiving the PDSCH using antennas except for the deactivated antennas; and

when the time gap is smaller than the transition time, receiving the PDSCH using all of the antennas.