Apparatus and method for adjusting receive beam gain in a wireless communication system

1. A method for adjusting a receive beam gain by a user equipment (UE) in a wireless communication system, the method comprising:

estimating a signal quality value based on a reference signal received from a base station (BS);

transmitting information related to the estimated signal quality value to the BS;

comparing the signal quality value with a signal quality threshold required for data reception; and

adjusting a first receive beam gain used for the data reception in comparison to a second receive beam gain used for a reception of the reference signal by adjusting a number of radio frequency (RF) chains in a turned on state among chains for antennas included in the UE based on a result of the comparison.

2. The method of claim 1 , wherein the adjusting of the first receive beam gain comprises:

if the signal quality value is less than the signal quality threshold, turning on at least one RF chain to increase the first receive beam gain used for the data reception to above the second receive beam gain used for the reception of the reference signal.

3. The method of claim 1 , wherein the adjusting of the first receive beam gain comprises:

if the signal quality value is larger than the signal quality threshold, turning off at least one RF chain to decrease the first receive beam gain used for the data reception to below the second receive beam gain used for the reception of the reference signal.

4. The method of claim 2 ,

wherein each of the RF chains for the antennas comprises:

an antenna,

a low noise amplifier (LNA), and

a phase shifter, and

wherein the method further comprises:

adjusting a phase shift value of a phase shifter included in the RF chain in the turned on state to make a reception beam direction after the adjusting of the first receive beam gain identical to a reception beam direction before the adjusting of the first receive beam gain.

5. The method of claim 1 , further comprising:

comparing the signal quality value with a predetermined threshold;

if the signal quality value is greater than the predetermined threshold, changing a predetermined beam class to a beam class having a relatively high receive beam gain;

if the signal quality value is less than the predetermined threshold, changing the predetermined beam class to a beam class having a relatively low receive beam gain; and

adjusting the first receive beam gain used for the data reception to a receive beam gain related to the changed beam class.

6. The method of claim 1 , further comprising:

transmitting beam class information to the BS, the beam class information including information related to at least one of beam classes managed by the UE, a number of reception beams included in each beam class, or a difference between receive beam gains of the beam classes.

7. The method of claim 1 , further comprising:

acquiring a modulation and coding scheme (MCS) level applied to data and an MCS offset being a difference between a reference signal transmission power and a data transmission power from control information received from the BS; and

determining the signal quality threshold based on the MCS level, a channel quality indicator (CQI), or the MCS level and the MCS offset.

8. The method of claim 1 , wherein the signal quality value comprises at least one of:

a path loss value,

a signal-to-noise ratio (SNR),

a signal-to-interference ratio (SIR),

a signal-to-interference plus noise ratio (SINR),

a signal-to-leakage plus noise ratio (SLNR),

a reference signal strength indicator (RSSI),

a reference signal received quality (RSRQ), or

a reference signal received power (RSRP).

9. A user equipment (UE) for adjusting a receive beam gain in a wireless communication system, the UE comprising:

at least one processor configured to:

estimate a signal quality value based on a reference signal received from a base station (BS),

compare the signal quality value with a signal quality threshold required for data reception, and

adjust a first receive beam gain used for the data reception in comparison to a second receive beam gain used for a reception of the reference signal by adjusting a number of radio frequency (RF) chains in a turned on state among chains for antennas included in the UE based on a result of the comparison; and

a transceiver configured to transmit information related to the estimated signal quality value to the BS.

10. The UE of claim 9 , wherein, if the signal quality value is less than the signal quality threshold, the at least one processor is further configured to turn on at least one RF chain to increase the first receive beam gain used for the data reception to above the second receive beam gain used for the reception of the reference signal.

11. The UE of claim 9 , wherein, if the signal quality value is larger than the signal quality threshold, the at least one processor is further configured to turn off at least one RF chain to decrease the first receive beam gain used for the data reception to below the second receive beam gain used for the reception of the reference signal.

12. The UE of claim 10 ,

wherein each of the RF chains for the antennas comprises:

an antenna,

a low noise amplifier (LNA), and

a phase shifter, and

wherein the at least one processor is further configured to:

adjust a phase shift value of a phase shifter included in the RF chain in the turned on state to make a reception beam direction after the adjusting of the first receive beam gain identical to a reception beam direction before the adjusting of the first receive beam gain.

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

compare the signal quality value with a predetermined threshold,

if the signal quality value is larger than the predetermined threshold, change a predetermined beam class to a beam class having a relatively high receive beam gain,

if the signal quality value is less than the predetermined threshold, change the predetermined beam class to a beam class having a relatively low receive beam gain, and

adjust the first receive beam gain used for the data reception to a receive beam gain related to the changed beam class.

14. The UE of claim 9 , wherein the transceiver is further configured to transmit beam class information to the BS, the beam class information including information related to at least one of beam classes managed by the UE, a number of reception beams included in each beam class, or a difference between receive beam gains of the beam classes.

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

acquire a modulation and coding scheme (MCS) level applied to data and an MCS offset being a difference between a reference signal transmission power and a data transmission power from control information received from the BS, and

determine the minimum signal quality value, taking into account the MCS level, a channel quality indictor (CQI), or the MCS level and the MCS offset.

16. The UE of claim 9 , wherein the signal quality value comprises at least one of:

a path loss value,

a signal-to-noise ratio (SNR),

a signal-to-interference ratio (SIR),

a signal-to-interference plus noise ratio (SINR),

a signal-to-leakage plus noise ratio (SLNR),

a reference signal strength indicator (RSSI),

a reference signal received quality (RSRQ), or

a reference signal received power (RSRP).