Method for allocating radio channels and base station apparatus utilizing the same
A base station apparatus includes a measurement unit, a derivation unit and an allocation unit. A base station apparatus allocates at least one subcarrier block, in a frequency band containing a plurality of subcarrier blocks composed of a plurality of subcarriers, to a terminal apparatus. The measurement unit measures an interference power of at least part of subcarriers among a plurality of subcarriers in each of the plurality of subcarrier blocks. The derivation unit derives, from the interference power of subcarriers measured by the measurement unit, an average value of the interference power for each of the plurality of subcarrier blocks and a statistical value indicating a degree of variation in the interference power relative to the average value. The allocation unit allocates at least one subcarrier block to the terminal apparatus, based on the average value and the statistical value derived by the derivation unit.
1. A base station apparatus for allocating at least one subcarrier block, in a frequency band containing a plurality of subcarrier blocks each composed of a plurality of subcarriers, to a terminal apparatus, the base station apparatus comprising:
a measurement unit which measures an interference power of at least part of subcarriers among a plurality of subcarriers in each of the plurality of subcarrier blocks;
a derivation unit which derives, from the interference power of subcarriers measured by said measurement unit, an average value of the interference power for each of the plurality of subcarrier blocks and a variance of the interference power indicating a degree of variation in the interference power relative to the average value; and
an allocation unit which allocates at least one subcarrier block to the terminal apparatus, based on the average value of the interference power and the variance of the interference power derived by said derivation unit.
2. A base station apparatus according to claim 1 , wherein when the average value of the interference power derived by said derivation unit is less than a predetermined threshold value, said allocation unit allocates terminal apparatuses in the order starting from a subcarrier block having a smaller variance of the interference power derived by said derivation unit.
3. A base station apparatus according to claim 1 , further comprising a receiver which receives, from a terminal apparatus, a signal containing an allocation request of the subcarrier block and a request quality required of the terminal,
wherein when the signal containing the allocation request is received anew by said receiver and a subcarrerier block that satisfies the request quality contained in the signal received by said receiver has already been allocated to another terminal apparatus, said allocation unit switches allocation of the subcarrier blocks according to a request quality required of the another terminal and a request quality required of a terminal apparatus to be allocated anew.
4. A base station apparatus according to claim 3 , said allocation unit including:
a storage which stores a relation between a required average value of the interference power and a required variance of the interference power for the request quality;
a selector which selects a required average value of the interference power and a required variance of the interference power corresponding respectively to a request quality required of the another terminal apparatus and a request quality required of the terminal apparatus to be allocated anew, by referring to the relation stored in the storage when the subcarrerier block that satisfies the request quality contained in the signal received by said receiver has already been allocated to the another terminal apparatus; and
an allocation execution unit which switches the subcarrier block allocated to the another terminal apparatus to an unused subcarrier block and allocates the subcarrier block allocated to the another terminal apparatus, to the terminal apparatus to be allocated anew, when an average value of the interference power and a variance of the interference power of the unused subcarrier block which has not been allocated to any terminal apparatuses are both less than a required average value of the interference power and a required variance of the interference power of the another terminal apparatus.
5. A base station apparatus according to claim 3 , wherein the request quality contained in the signal received by said receiver includes a required frequency bandwidth necessary for performing communications,
wherein when the required frequency bandwidth included in the request quality is narrower than a predetermined bandwidth, said allocation unit allocates to a terminal apparatus a subcarrier block in the order starting from the subcarrier block having a large average value of the interference power in subcarrier blocks whose average values are less than the predetermined threshold value, independently of the variance of the interference power derived by said derivation unit.
6. A base station apparatus according to claim 3 , wherein the request quality contained in the signal received by said receiver includes a delay tolerance indicating a degree to which a delay in a communication is allowed,
wherein when the delay tolerance included in the request quality is greater than a predetermined tolerance, said allocation unit allocates to a terminal apparatus in the order starting from a subcarrier block having a large variance of the interference power in subcarrier blocks whose variances of the interference power are less than a threshold value for the variances of the interference power.
7. An allocation method, comprising:
deriving an average value of an interference power for a subcarrier block composed of a plurality of subcarriers and a variance of the interference power indicating a degree of variation in the interference power relative to the average value, and
allocating at least one subcarrier block to a terminal apparatus, based on the derived average value of the interference power and the derived variance of the interference power.
8. A program stored in a non-transitory computer readable medium and executed by a computer, the program including the functions of:
deriving an average value of an interference power for a subcarrier block composed of a plurality of subcarriers and a variance of the interference power indicating a degree of variation in the interference power relative to the average value; and
allocating at least one subcarrier block to a terminal apparatus, based on the derived average value of the interference power and the derived variance of the interference power.
9. A base station apparatus, comprising:
an acquisition unit which acquires a delay tolerance, indicating a degree to which a delay in a communication is allowed, and required bandwidth information, indicating a bandwidth required for a communication, when the communication is performed with a terminal apparatus by allocating at least one subcarrier block, in a frequency band containing a plurality of subcarrier blocks each composed of a plurality of subcarriers, to the terminal apparatus;
a measurement unit which measures an interference power of at least part of subcarriers among a plurality of subcarriers in each of the plurality of subcarrier blocks;
a derivation unit which derives, from the interference power of subcarriers measured by said measurement unit, an average value of the interference power for each of the plurality of subcarrier blocks and a variance of the interference power indicating a degree of variation in the interference power relative to the average value; and
an allocation unit which allocates at least one subcarrier block to the terminal apparatus, based on the average value of the interference power and the variance of the interference power derived by said derivation unit and the delay tolerance and the required bandwidth information acquired by said acquisition unit.
10. A base station apparatus according to claim 9 , wherein a threshold value for the delay tolerance is defined as a threshold value for use in delay tolerance,
a threshold value for the bandwidth is defined as a threshold value for use in bandwidth,
a threshold value for the variance of the interference power is defined as a variance threshold value,
a threshold value for the average value of the interference power is defined as a threshold value for use in average values, and
when the delay tolerance is less than the delay threshold value and the required bandwidth information is greater than or equal to the bandwidth threshold value, a subcarrier block having an average value of the interference power less than the average threshold value and a variance of the interference power less than the variance threshold value is preferentially allocated to the terminal apparatus.
11. A base station apparatus according to claim 9 , wherein a threshold value for the delay tolerance is defined as a threshold value for use in delay tolerance,
a threshold value for the bandwidth is defined as a threshold value for use in bandwidth,
a threshold value for the variance of the interference power is defined as a variance threshold value,
a threshold value for the average value of the interference power is defined as a threshold value for use in average values, and
when the delay tolerance is less than the delay threshold value and the required bandwidth information is less than the bandwidth threshold value, a subcarrier block having an average value of the interference power greater than or equal to the average threshold value and a variance of the interference power less than the variance threshold value is preferentially allocated to the terminal apparatus.
12. A base station apparatus according to claim 9 , wherein a threshold value for the delay tolerance is defined as a threshold value for use in delay tolerance,
a threshold value for the bandwidth is defined as a threshold value for use in bandwidth,
a threshold value for the variance of the interference power is defined as a variance threshold value
a threshold value for the average value of the interference power is defined as a threshold value for use in average values, and
when the delay tolerance is greater than or equal to the delay threshold value and the required bandwidth information is greater than or equal to the bandwidth threshold value, a subcarrier block having an average value of the interference power less than the average threshold value and a variance of the interference power greater than or equal to the variance threshold value is preferentially allocated to the terminal apparatus.
13. A base station apparatus according to claim 9 , wherein a threshold value for the delay tolerance is defined as a threshold value for use in delay tolerance,
a threshold value for the bandwidth is defined as a threshold value for use in bandwidth,
a threshold value for the variance of the interference power is defined as a variance threshold value,
a threshold value for the average value of the interference power is defined as a threshold value for use in average values, and
when the delay tolerance is greater than or equal to the delay threshold value and the required bandwidth information is less than the bandwidth threshold value, a subcarrier block having an average value of the interference power greater than or equal to the average threshold value and a variance of the interference power greater than or equal to the variance threshold value is preferentially allocated to the terminal apparatus.