JP2013106076A - Radio resource allocation device, base station, and radio resource allocation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contribute to improvement of frequency efficiency of the entire radio communication system.SOLUTION: A radio resource allocation device comprises: an allocation priority calculation part 12 for calculating allocation priority for each set of a radio resource of an allocation unit and an allocation candidate terminal station, where the allocation priority shows a degree of priority of allocation of the set in an allocation object radio frame; a transmission data amount target value calculation part 13 for calculating a transmission data amount target value that is a target value of a data amount transmitted by the allocation candidate terminal station in the allocation object radio frame, for each allocation candidate terminal station; and a radio resource allocation part 14 for terminating additional radio resource allocation to the allocation candidate terminal station in a process of allocating the radio resource to the allocation candidate terminal station according to the allocation priority, when a transmittable data amount is not increased by the radio resource already allocated to the terminal station and an allocation candidate radio resource and a data amount that can be transmitted by the radio resource already allocated to the terminal station is equal to or more than the transmission data amount target value.

Description

  The present invention relates to a radio resource allocation device, a base station, and a radio resource allocation method.

  In recent years, for example, “LTE (Long Term Evolution)”, which is one of the standards of 3GPP (Third Generation Partnership Project), is known as a next-generation mobile communication method that realizes high-speed and broadband wireless transmission. In LTE, an orthogonal frequency division multiple access (OFDMA) system is used as a downlink (link from a base station to a terminal station), and an uplink (link from a terminal station to a base station) is used. A single carrier frequency division multiple access (SC-FDMA) system is used as the multiple access system.

  In LTE, frequency resources are divided into units called resource blocks (RB) and allocated to terminal stations. RB is a minimum unit when radio resources are allocated to a terminal station. The terminal station transmits a packet using one or a plurality of consecutive RBs. The radio resource allocation apparatus provided in the base station performs radio packet scheduling (frequency scheduling) for determining which RB is allocated to the terminal station for each subframe having a time length of 1 ms. Similar frequency scheduling is performed in other wireless communication standards (WiMAX, LTE-Advanced, IEEE802.16m, etc.).

  As a conventional wireless packet scheduling technique, for example, a technique described in Non-Patent Document 1 is known. In the wireless packet scheduling technique described in Non-Patent Document 1, heuristic frequency scheduling is performed while ensuring fairness of RB allocation between terminal stations. Specifically, the terminal station (k) to which the b-th RB is allocated in the i-th subframe is determined according to the equation (1).

However, r _{k ′, b} (i) is an instantaneous throughput in the RB that can be expected when the b-th RB is in the terminal station (k ′) in the i-th subframe. R _{k ′} (i) is the average throughput of the terminal station (k ′) obtained by communication up to the “i−1” th subframe. An expression that is an argument of the argmax function of Expression (1) is generally called a proportional fairness metric.

  Further, in the wireless packet scheduling technique described in Patent Document 1, in the process of sequentially assigning RBs to terminal stations as in Non-Patent Document 1, a predetermined RB addition termination condition (for example, for the terminal station to be assigned) If the frequency efficiency matches a certain frequency efficiency), the allocation of the RB to the terminal station is completed.

JP 2011-0297768 A

Pokhariyal, T. E. Kolding and P. E. Mogensen, “Performance of downlink frequency domain packet scheduling for the UTRAN Long Term Evolution,” IEEE PIMRC, 2006.

  However, the conventional radio packet scheduling technique described above has the following problems.

  In the wireless packet scheduling technique described in Non-Patent Document 1, a plurality of RBs having different channel qualities may be assigned to one terminal station. Here, in LTE, when a plurality of RBs are assigned to one terminal station, a packet must be transmitted using all of the plurality of RBs. Therefore, a terminal station to which a plurality of RBs having different channel qualities are assigned. Then, one packet that has been subjected to error correction coding at a determined coding rate must be transmitted using the plurality of RBs by using the same modulation scheme. However, for the terminal station, transmission efficiency may be better when only a RB with good channel quality is allocated and a modulation scheme with a high modulation index is used.

  In the wireless packet scheduling technique described in Patent Document 1, when the number of terminal stations is small or the frequency characteristics of the channel are almost flat, the frequency of one terminal station is difficult under the condition that diversity gain between terminal stations is difficult to obtain. If the allocation of RBs to the terminal station is terminated only under the efficiency condition, the RB usage rate of the entire frequency band of the radio communication system may eventually decrease.

  FIG. 8 is a graph showing an example of the relationship between frequency efficiency and the number of RBs used for communication for each MCS (Modulation and Coding Scheme) in LTE. As can be seen from FIG. 8, even in the same MCS, the frequency efficiency varies depending on the number of RBs used for communication. Therefore, even when it is determined that a certain number of RBs are allocated under certain frequency efficiency conditions in the process of increasing the number of RBs allocated to a certain terminal station, the frequency efficiency is further increased by additionally allocating RBs. Good things can happen.

  The present invention has been made in view of such circumstances, and provides a radio resource allocation device, a base station, and a radio resource allocation method that can contribute to improving the frequency efficiency of the entire radio communication system. Let it be an issue.

  In order to solve the above problems, a radio resource allocation device according to the present invention is a radio resource allocation device that allocates radio resources to a terminal station for each radio frame in a frequency division multiple access scheme, For each set of resources and allocation candidate terminal stations, an allocation priority calculation unit that calculates an allocation priority indicating the priority of allocation of the set in the allocation target radio frame, and for each allocation candidate terminal station A transmission data amount target value calculation unit that calculates a transmission data amount target value that is a target value of the data amount transmitted by the terminal station in the target radio frame, and a radio resource according to the allocation priority for the allocation candidate terminal station In the process of allocation, the amount of data that can be transmitted does not increase due to radio resources already allocated to the terminal station and radio resources that are candidates for allocation. And a radio resource allocation unit that terminates additional allocation of radio resources to the terminal station when the amount of data that can be transmitted by radio resources already allocated to the terminal station is equal to or greater than a transmission data amount target value. It is characterized by that.

  In the radio resource allocation device according to the present invention, the allocation candidate radio resource is a radio resource having a maximum allocation priority of the terminal station.

  In the radio resource allocation device according to the present invention, the allocation candidate radio resource is a radio resource having a maximum channel quality of the terminal station.

  In the radio resource allocation device according to the present invention, the transmission data amount target value is a data amount that can be transmitted while satisfying a predetermined communication quality.

  In the radio resource allocation device according to the present invention, the transmission data amount target value is a data amount that can be transmitted by MCS satisfying a predetermined communication quality.

  In the radio resource allocating device according to the present invention, the transmission data amount target value calculation unit recalculates a transmission data amount target value every time radio resources are allocated to a terminal station.

  In the radio resource allocating device according to the present invention, the transmission data amount target value calculation unit calculates a transmission data amount target value only at the start of radio resource allocation to a terminal station.

  A base station according to the present invention includes any one of the above-described radio resource allocation apparatuses, and performs radio resource allocation to a terminal station.

  A radio resource allocation method according to the present invention is a radio resource allocation method for allocating radio resources to a terminal station for each radio frame in a frequency division multiple access method, and is a set of allocation-unit radio resources and allocation candidate terminal stations. An allocation priority calculating step for calculating an allocation priority indicating a degree of priority for the allocation of the set in the allocation target radio frame, and for each allocation candidate terminal station, the terminal station in the allocation target radio frame A transmission data amount target value calculation step for calculating a transmission data amount target value that is a target value of the amount of data to be transmitted, and in the process of allocating radio resources according to the allocation priority to the allocation candidate terminal stations, The amount of data that can be transmitted by the already allocated radio resource and the allocation candidate radio resource does not increase, and the terminal A radio resource allocation step of ending the additional allocation of radio resources to the terminal station when the amount of data that can be transmitted by the already allocated radio resources is equal to or greater than the transmission data amount target value. .

  According to the present invention, it is possible to contribute to improving the frequency efficiency of the entire wireless communication system.

It is a schematic block diagram of the radio | wireless communications system which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless resource allocation apparatus 10 shown in FIG. 5 is a flowchart of radio resource allocation processing according to an embodiment of the present invention. It is a flowchart of the RB addition completion | finish determination processing which concerns on Example 1 of this invention. It is a flowchart of the RB addition completion | finish determination processing which concerns on Example 2 of this invention. It is a flowchart of the radio | wireless resource allocation process which concerns on Example 7 of this invention. It is a flowchart of the RB addition completion | finish determination process which concerns on Example 7 of this invention. It is a graph showing the example of the relationship of the frequency efficiency with respect to the RB number used for the communication for every MCS in LTE.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a radio communication system according to an embodiment of the present invention. In FIG. 1, the base station 1 includes a radio resource allocation device 10. The terminal station 2 communicates with the base station 1 by wireless connection. The base station 1 can communicate with a plurality of terminal stations 2 by wireless connection. The base station 1 and the terminal station 2 use LTE as a communication standard. The radio resource allocation device 10 determines which RB is allocated to the terminal station 2 for each subframe.

  FIG. 2 is a block diagram showing a configuration of the radio resource allocation device 10 shown in FIG. In FIG. 2, the radio resource allocation device 10 includes an input information acquisition unit 11, an allocation priority calculation unit 12, a transmission data amount target value calculation unit 13, a radio resource allocation unit 14, and an allocation result output unit 15.

  The input information acquisition unit 11 acquires input information. As input information, for all terminal stations 2 wirelessly connected to the base station 1, radio quality information for each RB (channel quality information between the base station 1 and the terminal station 2), data amount waiting for transmission, QoS (Quality of Service) request (transmission rate and allowable delay amount requested by the terminal station). Regarding these input information, the general base station 1 always holds the latest information. The input information acquisition unit 11 acquires the latest input information held by the base station 1.

  Based on the input information acquired by the input information acquisition unit 11, the allocation priority calculation unit 12 targets a set of one RB and one terminal station 2 for all allocation candidate RBs and all allocation candidate terminal stations 2 ( For each allocation candidate group), an allocation priority indicating the degree of priority of the allocation of the group in the RB allocation target subframe is calculated.

  The allocation priority includes, for example, an index (proportional fairness metric) indicating the fairness of radio resource allocation between the terminal stations 2, an index indicating the remaining time until the transmission deadline of transmission data (allowable delay metric), and a certain communication speed. It is calculated using an index for guaranteeing (guaranteed transmission rate metric) or an index representing channel quality.

  In this embodiment, the allocation priority is calculated using one RB as the minimum allocation unit of radio resources, but the allocation priority may be calculated using a plurality of RBs as the minimum allocation unit of radio resources.

  The transmission data amount target value calculation unit 13 calculates, for each allocation candidate terminal station 2, a target value (transmission data amount target value) of the data amount transmitted by the terminal station 2 in the RB allocation target subframe. A method for calculating the transmission data amount target value will be described later.

  The radio resource allocation unit 14 performs allocation in the RB allocation target subframe in order from the allocation candidate group having the highest allocation priority among the allocation candidate groups. The radio resource allocation unit 14 determines whether or not to end the allocation of RBs to the allocation candidate terminal station 2 using the transmission data amount target value.

  The allocation result output unit 15 outputs the RB allocated by the radio resource allocation unit 14 in the RB allocation target subframe and the information on the terminal station 2.

  Next, the overall operation flow of the radio resource assignment apparatus 10 shown in FIG. 2 will be described with reference to FIG. FIG. 3 is a flowchart of radio resource allocation processing according to the present embodiment. The flowchart of FIG. 3 shows radio resource allocation processing for one subframe.

  In FIG. 3, G is a set composed of identifiers (indexes) of all RBs as allocation candidates in the initial state. In the initial state, U is a set of identifiers (indexes) of all the allocation candidate terminal stations 2. G (u) is a set of identifiers of RBs assigned to the terminal station 2 whose identifier is u. The initial state of G (u) is an empty set (φ). Hereinafter, the terminal station 2 whose identifier is u is referred to as a terminal station u, and the RB whose identifier is g is referred to as RB_g. P (u, g) is the allocation priority for the allocation candidate set of the terminal station u and RB_g.

(Step S1)
Based on the input information acquired by the input information acquiring unit 11, the allocation priority calculating unit 12 targets all terminal stations u belonging to the set U and all RB_g belonging to the set G to all the allocations. Each allocation priority P (u, g) for the candidate set is calculated.

(Step S2)
The radio resource allocation unit 14 selects the terminal station u and RB_g having the highest allocation priority P (u, g) from the terminal stations u belonging to the set U and RB_g belonging to the set G.

(Step S3)
The radio resource allocation unit 14 performs an RB addition end determination process for the allocation candidate group (terminal station u, RB_g) selected in step S2. The RB addition end determination process will be described later.

(Step S4)
The radio resource allocation unit 14 proceeds to step S5 when the determination result of step S3 is the end of RB addition for the terminal station u, and proceeds to step S6 when it is not the end of RB addition for the terminal station u.

(Step S5)
The radio resource assignment unit 14 deletes the identifier (u) of the terminal station u from the set U. As a result, in the subframe, no additional RB allocation is performed for the terminal station u.

(Step S6)
The radio resource allocation unit 14 adds the identifier (g) of RB_g to the set G (u). Then, the radio resource allocation unit 14 deletes the identifier (g) of RB_g from the set G.

(Step S7)
When the set U is an empty set (φ) or the set G is an empty set (φ), the radio resource allocation unit 14 performs the process of FIG. 3 (radio resource allocation process of the subframe). finish. Otherwise, the process returns to step S2.

  Next, the transmission data amount target value calculation method and the RB addition end determination process according to the present embodiment will be described with reference to examples.

The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted at a predetermined error rate when the terminal station u uses an RB of the RB identifier group defined below. The RB identifier group includes a set G (u), an identifier (g), and an identifier ({g ′ | g′∈G, P (u, g ′) ≧ P (u ′, g ′) for ∀u′∈U. }).

In the first embodiment, for the terminal station u, in addition to the already assigned RBs belonging to G (u) and the current candidate RB_g, among the unassigned RB_g ′, the assignment priority with the terminal station u When RB_g ′ having P (u, g ′) higher than the allocation priority P (u ′, g ′) with another terminal station u ′ is allocated, a packet size that can be transmitted with a predetermined error rate is transmitted. The data amount target value (TBS ₂ ) is used.

FIG. 4 is a flowchart of the RB addition end determination process according to the first embodiment.
(Step S101)
The radio resource allocation unit 14 calculates a packet size (TBS ₀ ) that can be transmitted at a predetermined error rate when the terminal station u uses an RB belonging to the already allocated G (u). Further, the radio resource allocation unit 14 uses a packet size (TBS ₁ ) that can be transmitted at a predetermined error rate when the terminal station u uses the RB belonging to the already allocated G (u) and the current allocation candidate RB_g. Is calculated.

(Step S102)
When the packet size (TBS ₀ ) is equal to or larger than the packet size (TBS ₁ ), the radio resource allocation unit 14 proceeds to step S103, whereas when the packet size (TBS ₀ ) is smaller than the packet size (TBS ₁ ). Proceed to step S106.

(Step S103)
The radio resource allocation unit 14 calculates a transmission data amount target value (TBS ₂ ).

(Step S104)
When the packet size (TBS ₀ ) is equal to or larger than the transmission data amount target value (TBS ₂ ), the radio resource allocation unit 14 proceeds to step S105, while the packet size (TBS ₀ ) has the transmission data amount target value (TBS _2). ), The process proceeds to step S106.

(Step S105)
The radio resource allocation unit 14 ends the RB addition for the terminal station u.

(Step S106)
The radio resource allocation unit 14 continues RB addition for the terminal station u.

  In the first embodiment, in the process of assigning RBs to the terminal station u, even if the frequency efficiency decreases as a result of assigning RB_g according to the assignment priority, the assignment candidate having the highest assignment priority of the terminal station u For the RB, the radio resource allocation process is continued. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  In the first embodiment described above, “a packet size that can be transmitted at a predetermined error rate” is used, but “a packet size that can be transmitted under a wireless communication condition that achieves a predetermined wireless communication quality” is used. May be. An example of the wireless communication condition is MCS. The wireless communication quality is, for example, an error rate.

The second embodiment is a modification of the first embodiment. The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted by MCS ₁ when the terminal station u uses an RB of the RB identifier group defined below. The RB identifier group includes a set G (u), an identifier (g), and an identifier ({g ′ | g′∈G, P (u, g ′) ≧ P (u ′, g ′) for ∀u′∈U. }).

MCS ₁ is an MCS that achieves a predetermined error rate by using the RB belonging to G (u) to which the terminal station u has already been allocated and the current allocation candidate RB_g.

FIG. 5 is a flowchart of the RB addition end determination process according to the second embodiment.
(Step S201)
The radio resource allocation unit 14 calculates a packet size (TBS ₀ ) that can be transmitted at a predetermined error rate when the terminal station u uses an RB belonging to the already allocated G (u). Further, the radio resource allocation unit 14 uses a packet size (TBS ₁ ) that can be transmitted at a predetermined error rate when the terminal station u uses the RB belonging to the already allocated G (u) and the current allocation candidate RB_g. Is calculated. Further, when the terminal station u uses the RB belonging to the already allocated G (u) and the current allocation candidate RB_g, the radio resource allocating unit 14 transmits a packet of the packet size (TBS ₁ ) to a predetermined error rate. The MCS (MCS ₁ ) necessary for transmission is calculated. Subsequent steps S202 to S206 are the same as steps S102 to S106 in FIG. 4 of the first embodiment.

  In the process of allocating RBs to the terminal station u in the second embodiment, the allocation priority of the terminal station u is maximized even if the frequency efficiency is reduced as a result of RB_g being allocated according to the allocation priority. For the allocation candidate RBs, the radio resource allocation process is continued. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

The third embodiment is a modification of the first embodiment. The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted at a predetermined error rate when the terminal station u uses an RB of the RB identifier group defined below. This RB identifier group includes a set G (u), an identifier (g), and an identifier ({g ′ | g′∈G, C (u, g ′) ≧ C (u ′, g ′) for ∀u′∈U. }).

  C (u, g ′) is the channel quality of the terminal station u in the set of the terminal station u and RB_g ′. C (u ′, g ′) is the channel quality of the terminal station u in the set of the terminal station u ′ and RB_g ′. For example, SINR (Signal to Interference and Noise power Ratio) can be used as the channel quality.

  The flowchart of the RB addition end determination process according to the third embodiment is the same as that of FIG. 4 according to the first embodiment.

  In the third embodiment, in the process of assigning RBs to the terminal station u, even if the frequency efficiency decreases as a result of assigning RB_g according to the assignment priority, the allocation candidate having the maximum channel quality of the terminal station u is selected. The radio resource allocation process is continued for the RB. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  In addition, since it is determined whether to end or continue the radio resource allocation process based on the channel quality of the terminal station u, not on the allocation priority, the frequency efficiency can be more specialized.

The fourth embodiment is a modification of the second embodiment. The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted by MCS ₁ when the terminal station u uses an RB of the RB identifier group defined below. This RB identifier group includes a set G (u), an identifier (g), and an identifier ({g ′ | g′∈G, C (u, g ′) ≧ C (u ′, g ′) for ∀u′∈U. }).

  C (u, g ′) is the channel quality of the terminal station u in the set of the terminal station u and RB_g ′. C (u ′, g ′) is the channel quality of the terminal station u in the set of the terminal station u ′ and RB_g ′. For example, SINR (Signal to Interference and Noise power Ratio) can be used as the channel quality.

  The flowchart of the RB addition end determination process according to the fourth embodiment is the same as FIG. 5 according to the second embodiment.

  Similarly to the third embodiment, in the process of allocating RBs to the terminal station u in the fourth embodiment, even if the frequency efficiency decreases as a result of RB_g being allocated according to the allocation priority, the channel quality of the terminal station u is maximized. The radio resource allocation process is continued for the allocation candidate RB. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  In addition, since it is determined whether to end or continue the radio resource allocation process based on the channel quality of the terminal station u, not on the allocation priority, the frequency efficiency can be more specialized.

Example 5 is a combination of Example 1 and Example 3. The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted at a predetermined error rate when the terminal station u uses an RB of the RB identifier group defined below. This RB identifier group includes a set G (u), an identifier (g), an identifier ({g ′ | g′∈G, P (u, g ′) ≧ P (u ′, g ′)) and C (u, g ') ≧ C (u ′, g ′) for ∀u′∈U}).

  The flowchart of the RB addition end determination process according to the fifth embodiment is the same as that of FIG. 4 according to the first embodiment.

  In the fifth embodiment, in the process of assigning RBs to the terminal station u, even if the frequency efficiency decreases as a result of assigning RB_g according to the assignment priority, the assignment priority and channel quality of the terminal station u are maximized. The radio resource allocation process is continued for the allocation candidate RBs. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

The sixth embodiment is a combination of the second embodiment and the fourth embodiment. The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted by MCS ₁ when the terminal station u uses an RB of the RB identifier group defined below. This RB identifier group includes a set G (u), an identifier (g), an identifier ({g ′ | g′∈G, P (u, g ′) ≧ P (u ′, g ′)) and C (u, g ') ≧ C (u ′, g ′) for ∀u′∈U}).

  The flowchart of the RB addition end determination process according to the sixth embodiment is the same as that of FIG. 5 according to the second embodiment.

  Even in the process of allocating RBs to the terminal station u in the sixth embodiment, even if the frequency efficiency is reduced as a result of RB_g being allocated according to the allocation priority, the allocation priority and channel of the terminal station u are similar to those in the fifth embodiment. The radio resource allocation process is continued for the allocation candidate RB having the highest quality. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  FIG. 6 is a flowchart of a radio resource allocation process according to the seventh embodiment. The flowchart of FIG. 6 shows radio resource allocation processing for one subframe. In FIG. 6, portions corresponding to the respective steps in FIG.

In the seventh embodiment, the transmission data amount target value (TBS ₂ ) is calculated only once in the radio resource allocation process (step S300 in FIG. 6). The transmission data amount target value (TBS ₂ ) is a packet size that can be transmitted by MCS ₂ when the terminal station u uses an RB of the RB identifier group defined below. This RB identifier group includes identifiers ({g ′ | g′∈G, P (u, g ′) ≧ P (u ′, g ′) for ∀u′∈U}).

MCS ₂ is an MCS corresponding to the average channel quality of the terminal station u. As the MCS ₂ , for example, “Wideband CQI” of the terminal station u, average MCS when the terminal station u uses the RB of the RB identifier group, or a value giving an offset to those MCSs. Is available.

FIG. 7 is a flowchart of the RB addition end determination process according to the seventh embodiment.
(Step S301)
The radio resource allocation unit 14 calculates a packet size (TBS ₀ ) that can be transmitted at a predetermined error rate when the terminal station u uses an RB belonging to the already allocated G (u). Further, the radio resource allocation unit 14 uses a packet size (TBS ₁ ) that can be transmitted at a predetermined error rate when the terminal station u uses the RB belonging to the already allocated G (u) and the current allocation candidate RB_g. Is calculated.

(Step S302)
When the packet size (TBS ₀ ) is equal to or larger than the packet size (TBS ₁ ), the radio resource allocation unit 14 proceeds to step S303, while when the packet size (TBS ₀ ) is smaller than the packet size (TBS ₁ ). Proceed to step S305.

(Step S303)
When the packet size (TBS ₀ ) is equal to or larger than the transmission data amount target value (TBS ₂ ), the radio resource allocation unit 14 proceeds to step S304, while the packet size (TBS ₀ ) has the transmission data amount target value (TBS _2). ), The process proceeds to step S305.

(Step S304)
The radio resource allocation unit 14 ends the RB addition for the terminal station u.

(Step S305)
The radio resource allocation unit 14 continues RB addition for the terminal station u.

  In the seventh embodiment, in the process of assigning RBs to the terminal station u, even if the frequency efficiency decreases as a result of assigning RB_g according to the assignment priority, the assignment candidate having the highest assignment priority of the terminal station u For the RB, the radio resource allocation process is continued. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

Further, in the seventh embodiment, in the start stage of the radio resource allocation process (step S300), a packet that can be transmitted when the allocation candidate RB having the maximum allocation priority of the terminal station u is allocated to the terminal station u. The size is calculated based on the average channel quality of the terminal station u, and this calculated value is used as the transmission data amount target value (TBS ₂ ). As a result, it is possible to reduce the amount of calculation of radio resource allocation processing and allocate RBs up to a throughput that can be achieved with at least average channel quality. As a result, further improvement in frequency efficiency can be expected, and it is possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  According to the above-described embodiment, in the process of assigning RBs to the terminal station u according to the assignment priority, the amount of data that can be transmitted is increased by the RBs already assigned to the terminal station u and the assignment candidate RBs. In addition, when the amount of data that can be transmitted by the RBs already allocated to the terminal station u is equal to or larger than the transmission data amount target value, the additional allocation of RBs to the terminal station u is terminated. In other words, even if the amount of transmittable data does not increase due to the allocation of the next allocation candidate RB in addition to the already allocated RB to the terminal station u, the transmittable data amount is reduced. If the transmission data amount target value has not been reached, RB allocation to the terminal station u is continued. Thereby, further improvement in frequency efficiency can be expected, and it becomes possible to contribute to improvement in frequency efficiency of the entire wireless communication system.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1 ... Base station, 2 ... Terminal station, 10 ... Radio | wireless resource allocation apparatus, 11 ... Input information acquisition part, 12 ... Assignment priority calculation part, 13 ... Transmission data amount target value calculation part, 14 ... Radio | wireless resource allocation part, 15 ... allocation result output part

Claims (9)

A radio resource allocation device that allocates radio resources to a terminal station for each radio frame in a frequency division multiple access scheme,
An allocation priority calculating unit that calculates an allocation priority indicating the degree of priority of allocation of the set in a radio frame to be allocated for each set of allocation unit radio resources and allocation candidate terminal stations;
For each allocation candidate terminal station, a transmission data amount target value calculation unit that calculates a transmission data amount target value that is a target value of the data amount transmitted by the terminal station in the radio frame to be allocated;
In the process of allocating radio resources to the allocation candidate terminal station according to the allocation priority, the amount of data that can be transmitted by the radio resource already allocated to the terminal station and the allocation candidate radio resource does not increase, and A radio resource allocation unit that terminates additional allocation of radio resources to the terminal station when the amount of data that can be transmitted by the radio resource already allocated to the terminal station is equal to or greater than a transmission data amount target value;
A radio resource allocation device comprising:   The radio resource allocation apparatus according to claim 1, wherein the radio resource of the allocation candidate is a radio resource having the highest allocation priority of the terminal station.   The radio resource allocation apparatus according to claim 1 or 2, wherein the radio resource of the allocation candidate is a radio resource having a maximum channel quality of the terminal station.   The radio resource allocation device according to any one of claims 1 to 3, wherein the transmission data amount target value is a data amount that can be transmitted while satisfying a predetermined communication quality.   4. The radio resource allocation device according to claim 1, wherein the transmission data amount target value is a data amount that can be transmitted by MCS satisfying a predetermined communication quality. 5.   6. The radio resource allocation according to claim 1, wherein the transmission data amount target value calculation unit recalculates a transmission data amount target value every time radio resources are allocated to a terminal station. apparatus.   The radio resource according to any one of claims 1 to 5, wherein the transmission data amount target value calculation unit calculates a transmission data amount target value only at the start of allocation of radio resources to the terminal station. Allocation device.   A base station comprising the radio resource allocation device according to any one of claims 1 to 7 and performing radio resource allocation to a terminal station. A radio resource allocation method for allocating radio resources to a terminal station for each radio frame in a frequency division multiple access method,
An allocation priority calculating step for calculating an allocation priority indicating a degree of priority of allocation of the set in a radio frame to be allocated for each set of allocation-unit radio resources and allocation candidate terminal stations;
For each allocation candidate terminal station, a transmission data amount target value calculation step for calculating a transmission data amount target value that is a target value of the data amount transmitted by the terminal station in a radio frame to be allocated;
In the process of allocating radio resources to the allocation candidate terminal station according to the allocation priority, the amount of data that can be transmitted by the radio resource already allocated to the terminal station and the allocation candidate radio resource does not increase, and A radio resource allocation step for ending the additional allocation of radio resources to the terminal station when the amount of data that can be transmitted by the radio resource already allocated to the terminal station is equal to or greater than a transmission data amount target value;
A radio resource allocating method comprising:

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