Method and apparatus for distributing layers of multi-input multi-output system in base station of wireless communication system

1 . A method performed by a base station, the method comprising:

obtaining scheduling information for a plurality of cells supported by the base station;

determining a total number of layers for the plurality of cells using the scheduling information and a first layer metric;

in accordance with a determination that the total number of layers exceeds the number of layers supported by the base station, reducing the total number of layers using a second layer metric different from the first layer metric;

in accordance with a determination that the total number of layers is less than or equal to the number of layers supported by the base station, increasing the total number of layers using the second layer metric;

performing downlink scheduling based on the total number of layers; and

transmitting data based on the downlink scheduling.

2 . The method of claim 1 ,

wherein the number of layers supported by the base station corresponds to a processing capacity of the base station.

3 . The method of claim 1 , further comprising:

determining a layer for each cell based on a sum of a proportional fair (PF) values of user equipments (UEs).

4 . The method of claim 1 , further comprising:

determining a layer for each cell based on a number of UEs connected for each cell of the plurality of cells.

5 . The method of claim 1 , further comprising:

determining a layer for each cell of the plurality of cells according to channel information.

6 . The method of claim 1 , further comprising:

determining a layer for each cell using a temporal statistical indicator of the base station.

7 . The method of claim 1 , further comprising:

identifying whether an additional correction is required after the redistributing; and

performing, in response to the additional correction being required, the additional correction.

8 . The method of claim 1 ,

wherein a first layer of a plurality of layers in a first cell of the plurality of cells corresponds to a first stream of first data transmitted to a first UE,

wherein a second layer of the plurality of layers corresponds to a second stream of second data transmitted to a second UE, and

wherein the plurality of UEs comprises the first UE and the second UE.

9 . The method of claim 8 , further comprising:

determining the number of layers for the first cell based on first channel conditions at the first cell, a first velocity of the first UE, and a second velocity of the second UE.

10 . The method of claim 9 , wherein the first channel conditions comprises a signal to interference noise ratio (SINR) indicating the received signal field at the first UE, a modulation and coding scheme level (MCS-level) used by the first UE, and/or a channel quality indicator (CQI) indicating channel quality observed by the first UE.

11 . A base station comprising:

at least one transceiver;

memory; and

at least one processor, wherein the at least one processor is configured to:

obtain scheduling information for a plurality of cells supported by the base station;

determine a total number of layers for the plurality of cells using the scheduling information and a first layer metric;

in accordance with a determination that the total number of layers exceeds the number of layers supported by the base station, reduce the total number of layers using a second layer metric different from the first layer metric;

in accordance with a determination that the total number of layers is less than or equal to the number of layers supported by the base station, increase the total number of layers using the second layer metric;

perform downlink scheduling based on the total number of layers; and

transmit data based on the downlink scheduling.

12 . The base station of claim 11 ,

wherein the number of layers supported by the base station corresponds to a processing capacity of the base station.

13 . The base station of claim 11 , wherein the at least one processor is configured to:

determine a layer for each cell based on sum of a proportional fair (PF) values of user equipments (UEs).

14 . The base station of claim 11 , wherein the at least one processor is configured to:

determine a layer for each cell based on a number of the UEs connected for each cell of the plurality of cells.

15 . The base station of claim 11 , wherein the at least one processor is configured to:

determine a layer for each cell is based on channel information for each cell of the plurality of cells.

16 . The base station of claim 11 , wherein the at least one processor is configured to:

determine a layer for each cell based on a temporal statistical indicator of the base station.

17 . The base station of claim 11 , wherein the at least one processor is configured to:

identify whether an additional correction is required for the adding or reducing the number of layers; and

perform, responsive to the additional correction being required, the additional correction.