Resource allocation method and apparatus of base station in wireless communication system
A resource allocation method and a base station for shortening an operation for updating an average data rate in a per-user scheduling metric calculation in the wireless communication system adopting a Proportional Fairness scheduler are provided. The resource allocation method includes receiving, at a base station, a channel quality indicator from at least one mobile station to be allocated resources, calculating a data rate available for the at least one mobile station based on the channel quality indicator, calculating a scheduling metric by dividing the data rate by an average data rate of the at least one mobile station, determining a resource allocation priority based on the scheduling metric, allocating the resources to the at least one mobile station according to the resource allocation priority, and updating the average data rate of only the at least one mobile station allocated the resources.
1. A resource allocation method of a base station in a wireless communication system, the method comprising:
receiving a channel quality indicator from a mobile station;
acquiring, based on the channel quality indicator, a data rate if a resource is currently allocated to the mobile station;
obtaining an average data rate indicating a resource amount allocated to the mobile station during a time period;
reducing the average data rate of the mobile station after a predetermined time period according to a following equation:
T
avg
(
k
,
n
)
=
T
avg
(
k
,
n
-
1
)
(
T
-
1
T
)
N
where k denotes an index of the mobile station, n denotes time, Tavg denotes the average data rate allocated to the mobile station, T denotes the time period, and N denotes an update period of the average data rate;
calculating a scheduling metric by dividing the acquired data rate by the average data rate;
determining a resource allocation priority of the mobile station based on the scheduling metric; and
allocating the resource to the mobile station according to the resource allocation priority,
wherein the obtaining comprises:
if the resource is currently allocated to the mobile station, updating the average data rate using the acquired data rate which is acquired based on the channel quality indicator, and
if the resource is not currently allocated to the mobile station, not updating the average data rate.
2. The method of claim 1 , wherein the obtaining comprises maintaining the average data rate, which is obtained at a previous time point, of the mobile station if the resource is not currently allocated to the mobile station.
3. The method of claim 1 , wherein the obtaining comprises:
calculating the average data rate of the mobile station using a following equation:
T
avg
(
k
,
n
)
=
{
T
avg
(
k
,
n
-
1
)
+
1
T
-
1
R
(
k
,
n
)
,
terminal
with
allocated
resource
T
avg
(
k
,
n
-
1
)
,
terminal
without
allocated
resource
where k denotes an index of the mobile station, n denotes time, R denotes the acquired data rate allocated to the mobile station, Tavg denotes the average data rate allocated to the mobile station, and T denotes the time period.
4. A base station for allocating resources to mobile stations in a wireless communication system, the base station comprising:
a radio communication unit which transmits and receives signals to and from a mobile station;
a modem which demodulates the signals received from the mobile station to extract a channel quality indicator; and
a resource allocation scheduler which acquires, based on the channel quality indicator, a data rate if a resource is currently allocated to the mobile station, obtains an average data rate indicating a resource amount allocated to the mobile station during a time period, calculates a scheduling metric by dividing the acquired data rate by the average data rate, determines a resource allocation priority of the mobile station based on the scheduling metric, and allocates the resource to the mobile station according to the resource allocation priority,
wherein the resource allocation scheduler obtains the average data rate by updating the average data rate using the acquired data rate which is acquired based on the channel quality indicator if the resource is currently allocated to the mobile station, and not updating the average data rate if the resource is not currently allocated to the mobile station, and
wherein the resource allocation scheduler reduces the average data rate of the mobile station after a predetermined time period according to a following equation:
T
avg
(
k
,
n
)
=
T
avg
(
k
,
n
-
1
)
(
T
-
1
T
)
N
where k denotes an index of the mobile station, n denotes time, Tavg denotes the average data rate allocated to the mobile station, T denotes the time period, and N denotes an update period of the average data rate.
5. The base station of claim 4 , wherein the resource allocation scheduler maintains the average data rate, which is obtained at a previous time point, of the mobile station if the resource is not currently allocated to the mobile station.
6. The base station of claim 4 , wherein the resource allocation scheduler obtains the average data rate by calculating the average data rate of the mobile station using a following equation:
T
avg
(
k
,
n
)
=
{
T
avg
(
k
,
n
-
1
)
+
1
T
-
1
R
(
k
,
n
)
,
terminalwithallocatedresource
T
avg
(
k
,
n
-
1
)
,
terminalwithoutallocatedresource
where k denotes an index of the mobile station, n denotes time, R denotes the acquired data rate allocated to the mobile station, Tavg denotes the average data rate allocated to the mobile station, and T denotes the time period.