Apparatus and method for scheduling in wireless communication system
A base station is capable of performing a method for scheduling in a wireless communication system. In the method, a downlink channel measurement value received from a terminal is compared with a threshold. When the downlink channel measurement value is smaller than the threshold, an activation set for a handover of the terminal is determined. When the number of base stations inside the activation set is two or more, a Modulation and Coding Scheme (MCS) level is allocated to the terminal with consideration of the downlink channel measurement value. A wireless resource is allocated to the terminal with consideration of the allocated MCS level and a headroom of the terminal.
1. An apparatus of a base station in a wireless communication system, the apparatus comprising:
a Modulation and Coding Scheme (MCS) level determination unit configured to:
when a downlink channel measurement value received from a terminal is smaller than a threshold, determine an activation set for a handover of the terminal, and
when the number of base stations inside the activation set is two or more, allocate an MCS level to the terminal with consideration of the downlink channel measurement value; and
a wireless resource determination unit configured to allocate a wireless resource to the terminal with consideration of the allocated MCS level and a headroom of the terminal.
2. The apparatus of claim 1 , wherein when the number of the base stations inside the activation set is 1 or less, the MCS level determination unit allocates a specific MCS level to the terminal.
3. The apparatus of claim 1 , further comprising:
a first receiver configured to receive the downlink channel measurement value from the terminal;
a second receiver configured to receive an uplink transmission power value from the terminal;
an interference predictor configured to predict an interference given to an external sector; and
a margin determination unit configured to determine an adaptive transmission power margin by comparing an interference prediction value from the interference predictor with a reference value.
4. The apparatus of claim 3 , wherein when the number of the base stations inside the activation set is 1 or less, the MCS level determination unit is configured to determine an MCS level using the uplink transmission power value and the adaptive transmission power margin, and allocate the determined MCS level to the terminal.
5. The apparatus of claim 3 , wherein when at least one of: the downlink channel measurement value is greater than the threshold; and the number of the base stations inside the activation set is two or more, the MCS level determination unit comprises:
a first determination unit configured to determine a first MCS for the terminal according to the downlink channel measurement value received from the terminal;
a second determination unit configured to determine a second MCS for the terminal using the uplink transmission power value and the adaptive transmission power margin; and
a third determination unit configured to allocate a smaller MCS of the first MCS and the second MCS to the terminal.
6. The apparatus of claim 5 , wherein the second determination unit is configured to:
normalize the uplink transmission power value on a specific unit basis;
add the adaptive transmission power margin to the normalized transmission power value; and
determine the second MCS by comparing the added value with a reference.
7. The apparatus of claim 1 , wherein the downlink channel measurement value comprises a DownLink (DL) Carrier to Interference and Noise Ratio (CINR).
8. A scheduling method of a base station in a wireless communication system, the method comprising:
comparing a downlink channel measurement value received from a terminal with a threshold;
when the downlink channel measurement value is smaller than the threshold, determining an activation set for a handover of the terminal;
when the number of base stations inside the activation set is two or more, allocating a Modulation and Coding Scheme (MCS) level to the terminal with consideration of the downlink channel measurement value; and
allocating a wireless resource to the terminal with consideration of the allocated MCS level and a headroom of the terminal.
9. The method of claim 8 , further comprising, when the number of the base stations inside the activation set is 1 or less, allocating a specific MCS level to the terminal.
10. The method of claim 8 , further comprising:
receiving the downlink channel measurement value from the terminal;
receiving an uplink transmission power value from the terminal;
predicting an interference given to an external sector; and
determining an adaptive transmission power margin by comparing the interference prediction value with a reference.
11. The method of claim 10 , further comprising, when the number of the base stations inside the activation set is 1 or less, determining an MCS level using the uplink transmission power value and the adaptive transmission power margin, and allocating the determined MCS level to the terminal.
12. The method of claim 10 , further comprising:
when the downlink channel measurement value is greater than the threshold, determining a first MCS for the terminal according to the downlink channel measurement value received from the terminal;
determining a second MCS for the terminal using the uplink transmission power value and the adaptive transmission power margin; and
allocating a smaller MCS of the first MCS and the second MCS to the terminal.
13. The method of claim 10 , wherein the allocating of the MCS level comprises:
determining a first MCS for the terminal according to the downlink channel measurement value received from the terminal;
determining a second MCS for the terminal using the uplink transmission power value and the adaptive transmission power margin; and
allocating a smaller MCS of the first MCS and the second MCS to the terminal.
14. The method of claim 13 , wherein the determining of the second MCS comprises:
normalizing the uplink transmission power value on a specific unit basis;
adding the adaptive transmission power margin to the normalized transmission power value; and
determining the second MCS by comparing the added value with a reference.
15. The method of claim 8 , wherein the downlink channel measurement value comprises a DownLink (DL) Carrier to Interference and Noise Ratio (CINR).
16. A base station for use in a wireless communication system, the base station comprising:
an RF processor;
a modem; and
a scheduler, the scheduler comprising:
a Modulation and Coding Scheme (MCS) level determination unit configured to:
when a downlink channel measurement value received from a terminal is smaller than a threshold, determine an activation set for a handover of the terminal, and
when the number of base stations inside the activation set is two or more, allocate an MCS level to the terminal with consideration of the downlink channel measurement value; and
a wireless resource determination unit configured to allocate a wireless resource to the terminal with consideration of the allocated MCS level and a headroom of the terminal.
17. The base station of claim 16 , wherein when the number of the base stations inside the activation set is 1 or less, the MCS level determination unit allocates a specific MCS level to the terminal.
18. The base station of claim 16 , further comprising:
a first receiver configured to receive the downlink channel measurement value from the terminal;
a second receiver configured to receive an uplink transmission power value from the terminal;
an interference predictor configured to predict an interference given to an external sector; and
a margin determination unit configured to determine an adaptive transmission power margin by comparing an interference prediction value from the interference predictor with a reference value.
19. The base station of claim 18 , wherein when the number of the base stations inside the activation set is 1 or less, the MCS level determination unit is configured to determine an MCS level using the uplink transmission power value and the adaptive transmission power margin, and allocate the determined MCS level to the terminal.
20. The base station of claim 18 , wherein when at least one of: the downlink channel measurement value is greater than the threshold; and the number of the base stations inside the activation set is two or more, the MCS level determination unit comprises:
a first determination unit configured to determine a first MCS for the terminal according to the downlink channel measurement value received from the terminal;
a second determination unit configured to determine a second MCS for the terminal using the uplink transmission power value and the adaptive transmission power margin; and
a third determination unit configured to allocate a smaller MCS of the first MCS and the second MCS to the terminal.
21. The base station of claim 20 , wherein the second determination unit is configured to:
normalize the uplink transmission power value on a specific unit basis;
add the adaptive transmission power margin to the normalized transmission power value; and
determine the second MCS by comparing the added value with a reference.
22. The base station of claim 16 , wherein the downlink channel measurement value comprises a DownLink (DL) Carrier to Interference and Noise Ratio (CINR).