JP5679918B2 - Radio base station and communication control method - Google Patents

Description

  The present invention relates to a radio base station that performs communication by allocating a radio channel to a mobile station to be connected by radio, and a communication control method thereof.

  In a wireless communication system including a wireless base station and a mobile station, various studies have been made regarding a method for assigning a wireless channel for transmitting and receiving wireless signals (see, for example, Patent Document 1).

  In Patent Document 1, a radio channel is assigned to each mobile station using a priority based on a radio quality value between the radio base station and the mobile station in the radio channel.

JP 2005-86588 A

  When the technique as described above is performed with an advanced algorithm, a processing load is applied to the radio base station. Therefore, a radio base station having a single processor may be delayed in processing due to the influence of processing load, and may not be able to perform radio channel assignment processing to a mobile station at an appropriate timing.

  In order to solve such problems, in recent years, information devices such as computers have been subjected to parallel processing of data by multiprocessors in order to achieve higher processing capability. Similarly, a technique for processing data transmitted from a transmission apparatus such as a mobile station by parallel processing using a multiprocessor has also been proposed in a radio base station.

  However, even if radio channels are allocated to each mobile station using priority by parallel processing by a plurality of processors, it is not determined which radio resource is used by a mobile station with high priority. Since radio resources to be used by mobile stations with high priority cannot be determined, simply applying parallel processing cannot use the processing capability for radio channel allocation.

  The present invention has been made in view of such problems, and an object of the present invention is to reduce the processing time required for radio channel scheduling in a radio base station having a plurality of processors and capable of parallel processing. It is an object to provide a radio base station and a communication control method that can be reduced.

  In order to solve the above problems, a radio base station according to the present invention includes a receiving unit that receives information including a reception quality value of each radio channel within a usable radio frequency band from a mobile station, and the receiving unit includes: A control unit that assigns a radio channel to the mobile station that transmitted the information based on the received information, the control unit including a plurality of processing units, and one processing unit transmitted the information A first ranking of radio channel reception quality values is performed for each mobile station, and each of the other processing units is based on the first ranking for each mobile station performed by the one processing unit. And assigning a radio channel in charge of assignment.

  Further, the one processing unit corrects the reception quality value of each radio channel for each mobile station according to the first ranking, and based on the corrected reception quality value in each radio channel, A second ranking is performed in the mobile station that has transmitted the information, and each of the other plurality of processing units is a radio unit that is assigned based on the second ranking performed by the one processing unit. Channel assignment processing is performed.

  Each of the other plurality of processing units assigns a radio channel to the mobile station having the best reception quality value.

  In order to solve the above problems, a communication control method according to the present invention is a communication control method of a radio base station that performs radio communication with a mobile station, and the reception quality value of each radio channel within a usable radio frequency band. Including a reception step in which a reception unit receives information including the mobile station, and an assignment step in which a control unit allocates a radio channel to the mobile station that has transmitted the information based on the received information. In the assignment step, one processing unit in the plurality of processing units included in the control unit performs first ranking of the reception quality value of the radio channel for each mobile station that has transmitted the information, Each of the processing units performs assignment processing of a radio channel in charge of assignment based on the first ranking for each mobile station performed by the one processing unit.

  According to the present invention, the process of assigning a mobile station to each radio channel can be performed in parallel, so that the processing time required for radio channel scheduling can be reduced.

It is a figure which shows the structure of the radio | wireless communications system which concerns on 1st Embodiment of this invention. FIG. 3 is a functional block diagram of a radio base station according to the first embodiment of the present invention. It is a figure for demonstrating operation | movement of the control part of the wireless base station which concerns on 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the control part of the wireless base station which concerns on 1st Embodiment of this invention. It is a figure which shows the allocation candidate list which the wireless base station which concerns on 1st Embodiment of this invention produces | generates. 6 is a flowchart showing an operation of the radio base station according to the first embodiment of the present invention. It is a figure for demonstrating operation | movement of the control part of the wireless base station which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating operation | movement of the control part of the wireless base station which concerns on 2nd Embodiment of this invention. It is a figure which shows the allocation candidate list which the wireless base station which concerns on 2nd Embodiment of this invention produces | generates. It is a flowchart which shows operation | movement of the radio base station which concerns on 2nd Embodiment of this invention.

  Hereinafter, a first embodiment and a second embodiment according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a radio communication system 10 according to the first embodiment of the present invention. As shown in the figure, the radio communication system 10 includes a radio base station 20 and mobile stations 30 (30A, 30B, 30C, 30D). The radio base station 20 is called eNB (evolved Node B) in LTE (Long Term Evolution) and CS (Cell Station) in XGP (eXtended Global Platform), for example. The mobile station 30 is a wireless communication terminal in LTE, XGP, or the like. The radio base station 20 transmits and receives data by assigning a radio channel to the mobile station 30. The radio channel is referred to as a resource block (RB) in LTE and a PRU (Physical Resource Unit) in XGP.

  FIG. 2 is a functional block diagram of the radio base station 20 in the radio communication system 10.

  The radio base station 20 includes an antenna ANT, a radio communication unit 210, a modulation / demodulation unit 220, a storage unit 230, an I / F unit 240, and a control unit 250.

  The radio communication unit 210 receives a radio signal transmitted from the mobile station 30 via the antenna ANT. Further, the radio communication unit 210 converts the received radio signal into a baseband signal and outputs the baseband signal to the modulation / demodulation unit 220.

  Further, the wireless communication unit 210 converts the baseband signal input from the modulation / demodulation unit 220 into a wireless signal. Then, the radio communication unit 210 transmits a radio signal to the mobile station 30 via the antenna ANT.

  The modulation / demodulation unit 220 demodulates and decodes the baseband signal input from the wireless communication unit 210. As a result, data included in the radio signal transmitted from the mobile station 30 is obtained. The modulation / demodulation unit 220 outputs the obtained data to the control unit 250.

  The modulation / demodulation unit 220 encodes and modulates data input from the control unit 250 to obtain a baseband signal and outputs the baseband signal to the wireless communication unit 210.

  The storage unit 230 includes, for example, a memory and stores various types of information used for control in the radio base station 20. In addition, the storage unit 230 stores an assignment candidate list referred to by the control unit 250 when assigning a radio channel to the mobile station 30 to be wirelessly connected. Details of the allocation candidate list referred to by the control unit 250 will be described later.

  An I / F (interface) unit 240 communicates with a host device such as a management device via a network.

  The control unit 250 controls various functions provided in the radio base station 20.

  In addition, the control unit 250 allocates a radio channel to each mobile station 30 when transmitting / receiving data to / from the mobile station 30 to be wirelessly connected. At this time, the control unit 250 performs allocation processing of each radio channel by parallel processing. Therefore, the control unit 250 includes a main processing unit 252 and a plurality of sub-processing units 254 (254A, 254B, 254C, 254D), and each processing unit is configured by a CPU, for example.

  The main processing unit 252 generates an assignment candidate list that is referred to when each of the plurality of sub-processing units 254 assigns a radio channel to the mobile station 30, and stores the assignment candidate list in the storage unit 230.

Each of the slave processing units 254 performs an assignment process of assigning a radio channel of a location in charge to a mobile station 30 among a plurality of radio channels included in a radio frequency band that can be used by the radio base station 20. Here, the slave processing unit 254A is a wireless channel 1 described later, the slave processing unit 254B is a wireless channel 2 described later, the slave processing unit 254C is a wireless channel 3 described later, and the slave processing unit 254D is a wireless channel 4 described later. It is assumed that the allocation process is performed. And
Each of the slave processing units 254 extracts the allocation candidates of the mobile station 20 in the radio channel in charge from the allocation candidate list stored in the storage unit 230, and with respect to the top mobile station 20 of the extracted allocation candidates, Assign a radio channel.

  Next, the generation process of the allocation candidate list in the main processing unit 252 will be described with reference to FIGS.

  When generating the allocation candidate list, the main processing unit 252 first receives a plurality of radio channels included in a radio frequency band that can be used by the radio base station 20 from each mobile station 30 that is wirelessly connected, every predetermined time. Information including the quality value is received from each mobile station 30. Examples of the reception quality value include RSSI (Receive Signal Strength Indication) and SNR (Signal to Noise Ratio). In the first embodiment, RSSI is used. The information including the reception quality values received from each mobile station 30 by the main processing unit 252 is summarized as a table shown in FIG. The main processing unit 252 may generate the table shown in FIG. 3 and store it in the storage unit 230.

  Next, the main processing unit 252 uses the information including the reception quality value acquired from each mobile station 30 to rank the radio channels from the one having the good reception quality value for each mobile station 30 (first ranking). Append). FIG. 4 is a table showing the ranking results. As a result of ranking the radio channels, for example, in the mobile station 30A, the radio channel 3, radio channel 1, radio channel 2, and radio channel 4 are ranked in descending order of reception quality values. The main processing unit 252 may generate the table shown in FIG. 4 and store it in the storage unit 230.

  Next, the main processing unit 252 uses the rank of the reception quality value of the radio channel in each mobile station 30 to rank the mobile stations 30 to which each radio channel included in the usable radio frequency band is assigned (second Ranking). Then, the main processing unit 252 generates a list (assignment candidate list) indicating the assignment candidates of the mobile station 30 in each radio channel from the ranking result. The allocation candidate list generated by the main processing unit 252 is a table as shown in FIG. In generating the allocation candidate list, the main processing unit 252 uses the result of ranking (first ranking) performed for each mobile station 30 from the one with the good reception quality value of each radio channel. Therefore, as for the assignment to a certain radio channel, the higher the ranking of the mobile station 30, the higher the probability that the radio channel is assigned. For example, in the wireless channel 3, as shown in FIG. 4, the mobile station 30A is first, the mobile station 30B is fourth, the mobile station 30C is third, and the mobile station 30D is fourth. In this case, the main processing unit 252 sets the mobile station 30A as the first candidate for assignment in the wireless channel 3 as shown in FIG. To do.

  Next, radio channel assignment processing in the radio base station 20 in the first embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the radio base station 20.

  As shown in FIG. 6, in step S601, the control unit 250 of the radio base station 20 receives information including the reception quality value of each radio channel in the usable frequency band from each mobile station 30 wirelessly connected to its own station. Receive.

  In step S602, the main processing unit 252 of the control unit 250 uses the information including the reception quality value received from each mobile station 30 received in step S601, and performs radio communication for each mobile station 30 with a good reception quality value. Channel ranking (first ranking) is performed.

  In step S603, the main processing unit 252 uses the ranking of the reception quality value of the radio channel in each mobile station 30, and ranks the mobile station 30 when assigning each radio channel included in the usable radio frequency band ( 2nd ranking) is performed, an allocation candidate list is generated from the ranking result, and stored in the storage unit 230.

  In step S604, each of the secondary processing units 254 extracts allocation candidates of the mobile station 20 in the radio channel in charge from the allocation candidate list stored in the storage unit 230, and the highest mobile station 20 of the extracted allocation candidates. Is assigned a radio channel.

  As described above, in the first embodiment, the radio base station 20 refers to the allocation candidate list stored in the storage unit 230 and generated by the main processing unit 252 in the control unit 250, so that the sub processing unit 254 is referred to. Since the mobile station 30 to which the assigned radio channel is assigned can be specified, the processing time required when the radio channel assignment process is performed in parallel can be reduced.

(Second Embodiment)
In the first embodiment described above, the main processing unit 252 in the control unit 250 of the radio base station 20 uses the rank of the reception quality value of the radio channel in each mobile station 30 as it is when generating the allocation candidate list. Explained.

  In the second embodiment, when the main processing unit 252 generates the allocation candidate list, the reception quality of each radio channel is determined based on the ranking (first ranking) of the reception quality value of the radio channel in each mobile station 30. Correct the value. Then, the main processing unit 252 performs ranking (second ranking) of the mobile stations 30 using the corrected reception quality value, and generates an allocation candidate list using the ranking result. explain. In the following second embodiment, points different from the first embodiment will be described, and overlapping descriptions will be omitted.

  In the second embodiment, the radio base station 20 includes the same components as in the first embodiment, and the main processing unit 252 included in the control unit 250 generates an allocation candidate list and stores it in the storage unit 230. Remember.

  Next, the generation process of the allocation candidate list in the main processing unit 252 will be described with reference to FIGS.

  Similarly to the first embodiment, the main processing unit 252 receives information including the reception quality value of each radio channel from the mobile station 30, and uses the received information including the reception quality value for each mobile station 30. Then, the radio channels are ranked (first ranking) from the one having the good reception quality value (see FIGS. 3 and 4).

  Next, the main processing unit 252 adds a correction value according to the rank of the reception quality value of each radio channel in the mobile station 30 as shown in FIG. 7 to the reception quality value of each radio channel. The reception quality value of each radio channel in each mobile station 30 after the correction value is added by the main processing unit 252 is as shown in a table shown in FIG. The main processing unit 252 may generate the table shown in FIG. 8 and store it in the storage unit 230.

  Next, the main processing unit 252 uses each reception quality value of each radio channel in each mobile station 30 after adding the correction value, to move each radio channel included in the usable radio frequency band. The stations 30 are ranked (second ranking). Then, the main processing unit 252 generates a list (assignment candidate list) indicating assignment candidates of the mobile station 30 for each radio channel from the ranking result. The allocation candidate list generated by the main processing unit 252 is a table as shown in FIG. In generating this allocation candidate list, the main processing unit 252 ranks the radio channels with the highest reception quality values after correction. For this reason, the allocation to a certain radio channel has a higher probability that the radio channel is allocated to the mobile station 30 having a higher reception quality value of correction error. Therefore, for example, in the wireless channel 3 in the allocation candidate list, as shown in FIG. 9, the mobile station 30A is ranked first among the allocation candidates, and the mobile station C, the mobile station 30B, and the mobile station 30D are ranked in this order. .

  Next, radio channel assignment processing in the radio base station 20 in the second embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing the operation of the radio base station 20.

  As shown in FIG. 10, in step S1001, the control unit 250 of the radio base station 20 transmits each radio channel in the usable frequency band in each mobile station 30 from each mobile station 30 that is wirelessly connected to its own station. Receive information including the reception quality value.

  In step S1002, the main processing unit 252 of the control unit 250 uses the information including the reception quality value received from each mobile station 30 received in step S1001, and performs radio communication for each mobile station 30 with a good reception quality value. Channel ranking (first ranking) is performed.

  In step S1003, the main processing unit 252 uses the rank of the reception quality value of the radio channel in each mobile station 30, and adds a correction value corresponding to the rank of the reception quality value to each radio channel. To do.

  In step S1004, the main processing unit 252 assigns each radio channel included in the usable radio frequency band using the reception quality value of each radio channel in each mobile station 30 after adding the correction value. The mobile stations 30 are ranked (second ranking), an allocation candidate list is generated from the ranking result, and stored in the storage unit 230.

  In step S1005, each of the secondary processing units 254 extracts the allocation candidate of the mobile station 20 in the radio channel of the location in charge from the allocation candidate list stored in the storage unit 230, and moves the highest rank of the extracted allocation candidates. A radio channel is assigned to the station 20.

  As described above, in the second embodiment, the radio base station 20 refers to the assignment candidate list stored in the storage unit 230 and generated by the main processing unit 252 in the control unit 250, so that the sub processing unit 254 is referred to. Since the mobile station 30 to which the assigned radio channel is assigned can be specified, the processing time required when the radio channel assignment process is performed in parallel can be reduced.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, functions included in each component, each step, and the like can be rearranged so as not to be logically contradictory, and a plurality of means and steps can be combined into one or divided. is there.

  For example, in the first embodiment and the second embodiment described above, the main processing unit 252 does not perform the radio channel allocation process, but performs the radio channel allocation process in the same manner as the other sub-processing units 254. Also good.

10 wireless communication systems, 20 wireless base stations, 30 mobile stations, 210 wireless communication units, 220 modulation / demodulation units, 230 storage units, 240 I / F units, 250 control units, 252 main processing units, 254 sub processing units.

Claims (3)

A receiving unit that receives information including a reception quality value of each radio channel in the usable radio frequency band from the mobile station; and
A control unit that allocates a radio channel to a mobile station that has transmitted the information based on the information received by the receiving unit;
The controller is
A first ranking of radio channel reception quality values is performed for each mobile station that has transmitted the information, and a second ranking in the mobile station when assigning each radio channel is performed using the first ranking. A radio base station that performs radio channel assignment processing based on the second order . The control unit allocates a radio channel to the mobile station having the best reception quality value.
The radio base station according to claim 1 . A wireless base station communication control method for performing wireless communication with a mobile station,
A reception step in which a reception unit receives information including a reception quality value of each radio channel in an available radio frequency band from the mobile station; and
An assigning step of assigning a radio channel to a mobile station that has transmitted the information based on the received information;
In the assigning step,
A first ranking of radio channel reception quality values is performed for each mobile station that has transmitted the information, and a second ranking in the mobile station when assigning each radio channel is performed using the first ranking. Performing radio channel assignment processing based on the second order ,
A communication control method characterized by the above.

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