Uplink resource allocation method and cognitive small cell network system for executing same
View Patent ↗Disclosed are an uplink resource allocation method and a cognitive small cell network system performing the method. In the method, a small cell manager collects an access request from a small cell user and forms a preference relationship for each small cell user. Then, sub-channel-specific transmission power for providing a maximum data transmission rate at the time of uplink transmission is calculated and the calculated sub-channel-specific transmission power information is transferred to the small cell user. Meanwhile, the small cell user forms all possible sub-channel-specific preference relations and thereafter, transmits the access request for each sub-channel having a maximum preference relationship to the small cell manager. Thereafter, the small cell user performs power allocation for each access-determined sub-channel by using the transmission power information transferred from the small cell manager and performs data transmission through the access-determined sub-channel by using the allocated power.
1. A method for allocating an uplink resource by cognitive small cell user equipment in a cognitive small cell network, the method comprising:
forming a sub-channel-specific preference relationship for each of all possible sub-channels;
transmitting an access request for a sub-channel having a maximum preference relationship to a small cell manager;
receiving an answer for the access request;
determining whether the access request is admitted through the answer,
when it is determined that the access request is admitted, performing power allocation for each access-determined sub-channel by using transmission power information transferred from the small cell manager; and
performing data transmission through the access-determined sub-channel by using allocated power,
wherein when it is determined that the access request is rejected, the transmitting to the small cell manager is repeatedly performed until the access request is admitted.
2. The method of claim 1 , further comprising:
before the forming of the sub-channel-specific preference relationship,
receiving possible sub-channel information from a small cell base station through broadcasting.
3. The method of claim 1 , wherein:
the sub-channel-specific preference relationship is formed by assuming uniform transmission power to all possible sub-channels.
4. The method of claim 3 , wherein:
the sub-channel-specific preference relationship is estimated by utility values of all possible sub-channels, and
the utility values are calculated by the following relationship equation
U nm ( k )= R nm k
where R nm k represents a data transmission rate of a small cell user n when the small cell user n uses sub-channel k with respect to a small cell base station m, and
the R nm k is calculated by using the following relationship equation
R
n
m
k
=
B
k
log
2
(
1
+
g
n
m
k
P
n
m
k
g
n
m
k
P
k
0
k
+
σ
2
)
Where B k represents a bandwidth of sub-channel k, g nmk is a channel gain between small cell user equipment n and a small cell base station m, P nm k represents power allocated between small cell user equipment n and the small cell base station m, g km k P k0 k represents a interference level of a macro user k in the small cell base station m, and σ 2 represents Gaussian noise at the small cell base station.