JP5371696B2 - Radio base station, radio resource allocation method, and radio communication system - Google Patents

Description

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

  As a conventional wireless communication system, scheduling information including a data size waiting for transmission and a difference information Ph (Power Headroom) of current transmission power with respect to the maximum transmission power that can be transmitted is transmitted from the wireless terminal to the wireless base station. Based on this scheduling information, a radio base station determines the transmission power of the radio terminal and performs scheduling for controlling the data rate of transmission.

  Recently, for example, standardization of LTE (Long Term Evolution) is being promoted in 3GPP (3rd Generation Partnership Project). In LTE, a transmission band (resource block) having a plurality of subcarriers is allocated as an uplink radio resource (see, for example, Non-Patent Document 1). Therefore, in LTE, similarly to the conventional radio communication system, the radio base station determines the transmission power of the radio terminal based on the scheduling information including the difference information Ph from the radio terminal, and sets the transmission data rate. It is assumed that scheduling to control is performed.

3GPP TR25.814

  By the way, in a wireless communication system that performs communication by allocating wireless resources of different frequencies to a plurality of wireless terminals, the wireless state changes from time to time for each wireless resource due to the influence of frequency selective fading and the like. There may be a good radio resource and a radio resource in which the radio state is deteriorated. In this case, for the wireless terminal using the wireless resource whose wireless state has deteriorated, as described above, the transmission power is determined based on the difference information Ph from the wireless terminal, and the transmission data rate is set. By performing scheduling for control, it is possible to ensure desired communication quality.

  However, if there is no margin in the transmission power of the wireless terminal, when the wireless state of the wireless resource assigned to the wireless terminal is further deteriorated, it is no longer possible to control to increase the transmission power, and wireless communication with the wireless base station It becomes difficult to maintain the link. On the other hand, in general, a radio terminal using a radio resource with a good radio state generally has a margin in transmission power.

  Thus, in a wireless communication system that performs communication by allocating wireless resources of different frequencies to a plurality of wireless terminals, even if the transmission power is controlled based on the difference information Ph from the wireless terminal in the wireless base station, Depending on the wireless terminal, there is a concern that it may be difficult to maintain a wireless link with the wireless base station because there is no margin in transmission power.

  Accordingly, an object of the present invention made in view of such a point is to provide a radio base station, a radio resource allocation method, and a radio communication system that can appropriately control transmission power of a plurality of radio terminals and can stably maintain a radio link. It is to provide.

The invention of the radio base station according to the first aspect of achieving the above object is as follows:
In a radio base station that performs radio communication by assigning different radio resources to a plurality of radio terminals,
A measurement unit that measures a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
A difference information acquisition unit for acquiring difference information of a current transmission power with respect to a maximum transmission power transmitted from each of the plurality of wireless terminals;
A moving speed acquisition unit that acquires the moving speed of each of the plurality of wireless terminals;
A radio resource allocation standard corresponding to the moving speed acquired by the moving speed acquisition unit is set for each of the radio terminals, the radio resource allocation standard, the propagation loss measured by the measuring unit, and the difference information report acquisition based on the obtained difference information in parts, Bei example a control unit for controlling the allocation of radio resources for each of said plurality of wireless terminals,
The controller is
Propagation measured by the measurement unit for the radio terminal in which the difference information acquired by the difference information acquisition unit is less than a first threshold indicating the radio resource allocation criterion set for each radio terminal. Assigning the radio resource having a relatively small loss to the radio terminal in which the difference information acquired by the difference information acquisition unit is equal to or higher than a first threshold indicating the radio resource allocation criteria set in each radio terminal In this case, a resource having a relatively large propagation loss measured by the measurement unit is allocated .

The invention according to the second aspect is the radio base station according to the first aspect,
The moving speed acquisition unit acquires the moving speed of the wireless terminal based on a received signal from the wireless terminal.

The invention according to a third aspect, the radio base station according to the first or second aspect,
A communication type information acquisition unit for acquiring communication type information indicating the communication type of each of the plurality of wireless terminals;
The controller is
The wireless resource allocation criteria set for each of the wireless terminals , the propagation loss measured by the measurement unit, the difference information acquired by the difference information acquisition unit, and the communication type information acquired by the communication type information acquisition unit The wireless resource allocation to each of the plurality of wireless terminals is controlled based on the above.

The invention according to a fourth aspect, the radio base station according to the third aspect,
The controller is
Based on the propagation loss in each radio resource measured by the measurement unit, classify the plurality of radio resources into at least two radio resource groups,
Based on the wireless resource allocation criteria set for each of the wireless terminals, the difference information acquired by the difference information acquisition unit, and the communication type information acquired by the communication type information acquisition unit, the plurality of wireless terminals Control is performed so as to allocate radio resources of the corresponding radio resource group to each.

The invention according to a fifth aspect is the radio base station according to the fourth aspect ,
The controller is
Classifying the plurality of radio resources into at least two or more radio resource groups based on a comparison between a propagation loss in each radio resource measured by the measurement unit and a preset second threshold; To do.

The invention according to a sixth aspect is the radio base station according to the fourth or fifth aspect ,
The controller is
For each of the radio terminals, after determining the radio resource group to which radio resources are allocated based on the radio resource allocation criteria set for each of the radio terminals and the difference information acquired by the difference information acquisition unit, Based on the communication type information acquired by the communication type information acquisition unit, control is performed to allocate a radio resource having a relatively large or small propagation loss measured by the measurement unit within the determined radio resource group. It is characterized by that.

The invention according to a seventh aspect is the radio base station according to the fourth or fifth aspect ,
The controller is
After determining the radio resource group to which radio resources are allocated to the radio terminals based on the communication type information acquired by the communication type information acquisition unit, the radio resource allocation criteria set for each of the radio terminals Based on the difference information acquired by the difference information acquisition unit, control is performed so as to allocate a radio resource having a relatively large or small propagation loss measured by the measurement unit within the determined radio resource group. It is characterized by that.

Furthermore, the invention of the radio resource allocation method according to the eighth aspect of achieving the above object is as follows:
A radio resource allocation method in a radio base station that performs radio communication by allocating different radio resources to a plurality of radio terminals,
Measuring a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
Obtaining difference information of current transmission power with respect to maximum transmission power transmitted from each of the plurality of wireless terminals;
Obtaining a moving speed of each of the plurality of wireless terminals;
A radio resource allocation criterion according to the acquired moving speed is set for each of the radio terminals, and the plurality of the plurality of the radio resource allocation criteria, the measured propagation loss, and the acquired difference information based on the radio resource allocation criterion, the measured propagation loss, and controlling the allocation of radio resources for each of the wireless terminals, only including,
For the wireless terminal in which the acquired difference information is less than a first threshold value indicating the wireless resource allocation criterion set in each wireless terminal, the measured propagation loss is relatively small. A resource is allocated, and the measured propagation loss is relatively for the wireless terminal whose acquired difference information is equal to or higher than a first threshold value indicating the wireless resource allocation criterion set in each wireless terminal. It is characterized by allocating large resources .

Furthermore, the invention of the wireless communication system according to the ninth aspect for achieving the above object is as follows:
In a wireless communication system in which different wireless resources are allocated to a plurality of wireless terminals by a wireless base station, and wireless communication is performed between the wireless base station and the plurality of wireless terminals,
Each of the plurality of wireless terminals is
A calculation unit that calculates a difference between the current transmission power and the maximum transmission power that can be transmitted by the wireless terminal, and outputs difference information;
A transmission unit for transmitting the difference information output from the calculation unit to the radio base station,
The radio base station is
A measurement unit that measures a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
A difference information acquisition unit for acquiring difference information of a current transmission power with respect to a maximum transmission power transmitted from each of the plurality of wireless terminals;
A moving speed acquisition unit that acquires the moving speed of each of the plurality of wireless terminals;
A radio resource allocation standard corresponding to the moving speed acquired by the moving speed acquisition unit is set for each of the radio terminals, the radio resource allocation standard, the propagation loss measured by the measuring unit, and the difference information report acquisition A control unit that controls allocation of the radio resource to each of the plurality of radio terminals based on the difference information acquired by the unit, and
The controller is
Propagation measured by the measurement unit for the radio terminal in which the difference information acquired by the difference information acquisition unit is less than a first threshold indicating the radio resource allocation criterion set for each radio terminal. Assigning the radio resource having a relatively small loss to the radio terminal in which the difference information acquired by the difference information acquisition unit is equal to or higher than a first threshold indicating the radio resource allocation criteria set in each radio terminal In this case, a resource having a relatively large propagation loss measured by the measurement unit is allocated .

  According to the present invention, the base station acquires the moving speed of each radio terminal, sets the radio resource allocation reference for each radio terminal according to the acquired moving speed, and sets the radio resource at each predetermined timing. Measure the propagation state, acquire the difference information of the current transmission power with respect to the maximum transmission power from each wireless terminal, and based on these set radio resource allocation criteria, the measured propagation state, and the acquired difference information, a plurality of Controls allocation of radio resources to radio terminals. Therefore, it is possible to appropriately control the transmission power of a plurality of wireless terminals, and it is possible to stably maintain the wireless link between each wireless terminal and the wireless base station.

It is a figure which shows schematic structure of the radio | wireless communications system which has a radio base station which concerns on 1st Embodiment of this invention. 3 is a flowchart showing radio resource block allocation scheduling operation by the radio base station shown in FIG. 1. It is a schematic diagram which shows allocation of the radio | wireless resource block by the radio base station which concerns on 1st Embodiment of this invention. It is a figure which shows schematic structure of the radio | wireless communications system which has a radio base station which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the allocation scheduling operation | movement of the radio | wireless resource block by the radio base station which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the allocation scheduling operation | movement of the radio | wireless resource block by the radio base station which concerns on 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a radio communication system having a radio base station according to the first embodiment of the present invention. This radio communication system is based on, for example, LTE, and a radio base station 10 according to the present embodiment assigns different radio resource blocks to a plurality of radio terminals 20 (only one is shown in FIG. 1). Allocating and performing wireless communication between the wireless base station 10 and the plurality of wireless terminals 20.

  The radio base station 10 includes a radio communication unit 11, a propagation loss measurement unit 12, a Ph acquisition unit 13, a movement speed acquisition unit 14, and a control unit 15. The wireless communication unit 11 performs wireless communication with a plurality of wireless terminals 20. The propagation loss measurement unit 12 measures the propagation loss in each radio resource block assigned to the plurality of radio terminals 20 at predetermined timing based on the received signal obtained from the radio communication unit 11, and the measurement result Is supplied to the control unit 15.

  Here, the predetermined timing for measuring the propagation loss is, for example, a processing unit time defined by the system, for example, a subframe (1 ms) in a radio frame. Further, the propagation loss is measured based on, for example, the received electric field strength and packet loss in each radio resource block.

  The Ph acquisition unit 13 constitutes a difference information acquisition unit, and acquires the difference information Ph of the current transmission power with respect to the maximum transmission power transmitted from each wireless terminal 20 based on the reception signal obtained from the wireless communication unit 11. Then, the acquired difference information Ph is supplied to the control unit 15.

  The moving speed acquisition unit 14 acquires the moving speed of each wireless terminal 20 and supplies the result to the control unit 15. For example, the moving speed acquisition unit 14 acquires the moving speed of each wireless terminal 20 by grasping the fluctuation state of the propagation path. That is, the moving speed acquisition unit 14 periodically acquires the received power value of the received radio signal of each radio terminal 20, grasps the fluctuation, and whether the moving speed of each radio terminal 20 is equal to or higher than a predetermined threshold value. Judge whether or not.

  The control unit 15 controls the operation of the entire radio base station. Further, the control unit 15 sets, for example, the radio resource allocation reference Phref for the radio terminal 20 whose movement speed is equal to or higher than a predetermined threshold, to a high value according to the determination result by the movement speed acquisition unit 14, and the movement speed is predetermined. The radio resource allocation reference Phref for the radio terminal 20 that is less than the threshold is set to a low value. In addition, the control unit 15 sets the wireless loss set according to the propagation loss measured by the propagation loss measurement unit 12, the difference information Ph acquired by the Ph acquisition unit 13, and the moving speed of the wireless terminal 20 at every predetermined timing. Based on the resource allocation criterion Phref, the allocation (scheduling) of radio resource blocks to a plurality of radio terminals 20 is controlled (scheduled), and the result is transmitted to the corresponding radio terminal 20 via the radio communication unit 11.

  In the radio base station 10, the propagation loss measurement unit 12, the Ph acquisition unit 13, the movement speed acquisition unit 14, and the control unit 15 are configured by one CPU (central processing unit). The processing of the propagation loss measurement unit 12, the Ph acquisition unit 13, the movement speed acquisition unit 14, and the control unit 15 may be shared and executed by the CPU.

  On the other hand, each wireless terminal 20 includes a wireless communication unit 21, a Ph calculation unit 22, and a control unit 23. The radio communication unit 21 includes a transmission unit and a reception unit, and performs communication with the radio base station 10 using the allocated radio resource block. The Ph calculation unit 22 calculates the difference between the current transmission power and the maximum transmission power that can be transmitted by the wireless terminal 20, and supplies the difference information Ph to the control unit 23. The control unit 23 controls the operation of the entire wireless terminal, and the difference information Ph obtained from the Ph calculation unit 22 is transmitted via the wireless communication unit 21 periodically or at a timing requested from the wireless base station 10. To transmit (notify) to the radio base station 10.

  FIG. 2 is a flowchart showing a radio resource block allocation scheduling operation by radio base station 10 according to the present embodiment. The control unit 15 acquires the propagation loss of all radio resource blocks from the propagation loss measurement unit 12 at every predetermined timing (step S11). Moreover, the control part 15 acquires the difference information Ph of each radio | wireless terminal 20 from the Ph acquisition part 13 (step S12). In addition, the control unit 15 acquires the moving speed of each wireless terminal 20 from the moving speed acquisition unit 14, and determines the wireless resource allocation reference Phref (step S13). And the control part 15 compares the difference information Ph acquired from the Ph acquisition part 13, and the radio | wireless resource allocation reference | standard Phref determined based on the moving speed of each terminal acquired from the moving speed acquisition part 14 (step S14). .

  As a result, when Ph ≧ Phref, there is a margin in transmission power, so that the control unit 15 assigns radio resource blocks to the radio terminal 20 so that radio resources blocks with large propagation loss are preferentially assigned. Is scheduled (step S15), and the result is transmitted to the corresponding wireless terminal 20. On the other hand, when Ph <Phref, there is no margin in transmission power, so that the control unit 15 assigns a radio resource block with a small propagation loss to the radio terminal 20 preferentially. The allocation is scheduled (step S16), and the result is transmitted to the corresponding wireless terminal 20.

  In this way, the control unit 15 changes the radio resource block allocated to each radio terminal 20 at each predetermined timing according to the radio status of each radio resource block, which changes from time to time, and the radio status of each radio resource block, Scheduling is performed according to the moving speed of each wireless terminal and the difference information Ph of each wireless terminal.

  FIG. 3 is a schematic diagram showing radio resource block allocation by the radio base station 10 according to the present embodiment. In FIG. 3, the horizontal axis indicates time and the vertical axis indicates frequency. The processing unit time corresponds to a predetermined timing for scheduling the allocation of radio resource blocks. As is apparent from FIG. 3, the allocation state of the radio resource blocks to the plurality of radio terminals indicated by users 1 to n is the radio status of each radio resource block and the radio terminals in sequential processing unit time (predetermined timing). Is changed according to the moving speed and the difference information Ph of each wireless terminal. FIG. 3 shows a case where one radio resource block is allocated to each user (wireless terminal). However, when the number of connected terminals is small, a plurality of radio resource blocks are allocated to one radio terminal. There is also a case of scheduling.

  As described above, the radio communication system having the radio base station 10 according to the present embodiment sets the radio resource allocation reference Phref based on the moving speed of each radio terminal 20. For example, Phref is set high for the wireless terminal 20 whose moving speed is equal to or higher than a predetermined threshold, and Phref is set low for the wireless terminal 20 whose moving speed is less than the predetermined threshold. Therefore, as a result of comparing the difference information Ph and Phref with respect to the wireless terminal 20 having a high moving speed, the probability that Phref is determined to be larger increases. Since the difference information Ph is less than the radio resource allocation standard Phref and the radio terminal 20 determined to have no transmission power, a radio resource block with a small propagation loss, that is, a radio state is preferentially allocated. The wireless link of the wireless terminal 20 can be reliably maintained. In addition, a radio resource block having the difference information Ph equal to or higher than the radio resource allocation reference Phref is preferentially allocated with a radio resource block having a large propagation loss, that is, a bad radio state. Since there is room, the radio link can be maintained by appropriately controlling the transmission power. Therefore, the transmission power of each radio terminal 20 can be controlled appropriately, and the radio link between each radio terminal 20 and the radio base station 10 can be stably maintained. In addition, since the radio base station 10 can know the propagation loss of all radio resource blocks at every predetermined timing, the radio base station 10 follows the temporal change in the radio state, and performs the downlink modulation scheme, antenna beamforming, etc. It is also possible to control.

(Second Embodiment)
FIG. 4 is a diagram showing a schematic configuration of a radio communication system having a radio base station according to the second embodiment of the present invention. The radio base station 30 according to the present embodiment is obtained by further providing a communication type information acquisition unit 31 in the radio base station 10 shown in FIG. The communication type information acquisition unit 31 recognizes the type of communication with each wireless terminal 20, acquires the communication type information, and supplies the communication type information to the control unit 15. In the present embodiment, in the communication type information acquisition unit 31, the communication type information includes, for example, a communication type (T 1) that requires real-time properties such as voice communication and streaming, and other communication types of data communication such as browsing ( And is supplied to the control unit 15.

  The control unit 15 is acquired by the propagation loss measured by the propagation loss measurement unit 12, the difference information Ph acquired by the Ph acquisition unit 13, the moving speed acquisition unit 14, and the communication type information acquisition unit 31 at every predetermined timing. Based on the received communication type information, allocation (scheduling) of radio resource blocks to a plurality of radio terminals 20 is controlled (scheduled), and the result is transmitted to the corresponding radio terminal 20 via the radio communication unit 11. Other configurations and operations are the same as those in FIG.

FIG. 5 is a flowchart showing a radio resource block allocation scheduling operation by radio base station 30 according to the present embodiment. As in the case of the first embodiment, the control unit 15 acquires the propagation loss of all radio resource blocks from the propagation loss measurement unit 12 at each predetermined timing (step S21), and from the Ph acquisition unit 13 The difference information Ph of the wireless terminal 20 is acquired (step S22). In addition, the control unit 15 acquires the moving speed of each wireless terminal 20 from the moving speed acquisition unit 14, and determines the radio resource allocation reference Phref (step S23). Furthermore, in this Embodiment, the control part 15 acquires the communication classification information of each radio | wireless terminal 20 classified from the communication classification information acquisition part 31 for every predetermined timing (step S24).

  And the control part 15 compares the difference information Ph of the said radio | wireless terminal 20, and the radio | wireless resource allocation reference | standard Phref set based on the movement speed which the movement speed acquisition part 14 acquired with respect to each radio | wireless terminal 20 ( Step S25). As a result, in the case of Ph <Phref, there is no transmission power, so the control unit 15 further determines whether or not the communication type of the wireless terminal 20 is the communication type T1 that requires real-time performance. (Step S26).

  As a result, when the communication type is T1, the control unit 15 schedules the allocation of radio resource blocks so that the radio resource block with low propagation loss is preferentially allocated to the radio terminal 20 (step S27). The result is transmitted to the corresponding wireless terminal 20.

  On the other hand, when the communication type is T2, since the real-time property is not required, the control unit 14 assigns the radio resource to the radio terminal 20 so that the radio resource block having an intermediate propagation loss is preferentially assigned. Block allocation is scheduled (step S28), and the result is transmitted to the corresponding wireless terminal 20.

On the other hand, in Step S25, when Ph ≧ Phref, there is a margin in transmission power. In this case, as in the case of the first embodiment, the control unit 15 transmits a propagation loss to the radio terminal 20. Radio resource block allocation is scheduled so as to preferentially allocate radio resource blocks with large (step S29), and the result is transmitted to the corresponding radio terminal 20.

  In this way, the radio resource block allocated to each radio terminal 20 is assigned to each radio terminal 20 at a predetermined timing according to the radio status of each radio resource block that changes from moment to moment by the control unit 15. Scheduling is performed according to terminal difference information Ph, moving speed, and communication type.

  According to the radio communication system having the radio base station 30 according to the present embodiment, the difference information Ph is less than the radio resource allocation reference Phref set based on the moving speed of each radio terminal 20, and real-time performance is required. The radio terminal 20 that performs communication of the communication type T1 is preferentially assigned a radio resource block with a small propagation loss, that is, a good radio state. Therefore, in addition to the effect of the first embodiment, it is possible to more stably maintain the wireless link of the communication type T1 that requires real-time performance, and the QoS (Quality of Service) of the communication type T1. Can be secured.

  In Step S25 of FIG. 5, if Ph ≧ Phref, it is determined whether or not the communication type is T1, and in the case of communication type T1, a radio resource block with a small propagation loss is preferentially assigned, and the communication type T2 In this case, a radio resource block with a large propagation loss can be preferentially allocated.

  Furthermore, in FIG. 5, the control unit 15 can also compare Ph and Phref after determining the communication type by reversing the processing order of steps S25 and S26. That is, in step S25, the control unit 15 determines whether or not the communication type of the wireless terminal 20 is a communication type T1 that requires real-time characteristics, and in step S26, for each wireless terminal 20, The difference information Ph of the wireless terminal 20 and the wireless resource allocation reference Phref set based on the moving speed acquired by the moving speed acquisition unit 14 can also be compared.

  Even in this case, when it is determined that the communication type is not T1, the difference information Ph is further compared with the radio resource allocation reference Phref. If Ph ≧ Phref, the propagation loss is large. A radio resource block is allocated, and when Ph <Phref, a radio resource block with a small propagation loss can be preferentially allocated.

(Third embodiment)
In the radio base station according to the third embodiment of the present invention, in the configuration shown in FIG. 4, the control unit 15 assigns a plurality of radio resource blocks to a plurality of radio resource blocks based on the acquired propagation loss of each radio resource block. The radio resource group is classified, and the allocation of radio resource blocks is scheduled based on the comparison result between the difference information Ph of each radio terminal 20 and the radio resource allocation reference Phref and the communication type of each radio terminal 20.

  FIG. 6 is a flowchart showing radio resource block allocation scheduling operation by the radio base station 10 according to the third embodiment of the present invention. The control unit 15 acquires the propagation loss of all radio resource blocks from the propagation loss measurement unit 12 at every predetermined timing (step S31). Then, the control unit 15 classifies the plurality of radio resource blocks into a plurality of radio resource groups based on a comparison between the acquired propagation loss of each radio resource block and a preset threshold for propagation loss. In this embodiment, the propagation loss threshold is one, and the propagation loss is less than the threshold, that is, the group A in which the radio state is good, and the propagation loss is greater than the threshold, that is, the group B in which the radio state is relatively bad. Classify into radio resource groups (step S32).

  In addition, the control unit 15 acquires the moving speed of each wireless terminal 20 from the moving speed acquisition unit 14, and determines the wireless resource allocation reference Phref for each wireless terminal 20 (step S33). And the control part 15 acquires the difference information Ph of each radio | wireless terminal 20 from the Ph acquisition part 13 for every predetermined timing (step S34), and communication of each radio | wireless terminal 20 classified from the communication classification information acquisition part 14 Type information is acquired (step S35).

  And the control part 15 compares the difference information Ph of the said radio | wireless terminal 20, and the radio | wireless resource allocation reference | standard Phref set based on the movement speed which the movement speed acquisition part 14 acquired with respect to each radio | wireless terminal 20 ( Step S36). As a result, in the case of Ph <Phref, there is no transmission power, so the control unit 15 further determines whether or not the communication type of the wireless terminal 20 is the communication type T1 that requires real-time performance. (Step S37).

  As a result, when the communication type is T1, the control unit 15 preferentially assigns a radio resource block with a smaller propagation loss among the radio resource blocks of the group A to the radio terminal 20. Block allocation is scheduled (step S38), and the result is transmitted to the corresponding wireless terminal 20.

  On the other hand, when the communication type is T2, real-time performance is not required, so the control unit 15 allocates a radio resource block with a large propagation loss among the radio resource blocks of group A to the radio terminal 20. Thus, the allocation of radio resource blocks is scheduled (step S39), and the result is transmitted to the corresponding radio terminal 20.

  On the other hand, if Ph ≧ Phref in Step S36, there is a margin in transmission power, so the control unit 15 determines whether or not the communication type is T1 (Step S40). The radio resource block is scheduled to be allocated so as to preferentially allocate a radio resource block with a small propagation loss among the radio resource blocks of group B to the radio terminal 20 (step S41). Transmit to the wireless terminal 20.

  On the other hand, in the case of communication type T2, the control unit 15 assigns radio resource blocks to the radio terminal 20 so that radio resource blocks having a large propagation loss among radio resource blocks of group B are assigned. Scheduling is performed (step S42), and the result is transmitted to the corresponding wireless terminal 20.

  In this way, the control unit 15 assigns the radio resource block to be assigned to each radio terminal 20 at each predetermined timing according to the radio status of each radio resource block that changes from time to time. Scheduling is performed according to the difference information Ph of the wireless terminal, the moving speed, and the communication type.

  According to such a scheduling operation, the radio terminal 20 whose difference information Ph is equal to or higher than the radio resource allocation reference Phref set based on the moving speed of each radio terminal 20 has a large propagation loss, that is, in the radio state. Although the radio resource block of the bad group B is selected, since the radio terminal 20 has a sufficient transmission power, the radio link can be maintained by appropriately controlling the transmission power. Moreover, in this case as well, a radio resource block having a small propagation loss in the group B, that is, a radio resource block having a good radio state is given priority to the radio terminal 20 performing communication of the communication type T1 requiring real-time performance. Therefore, QoS of the communication type T1 can be secured more stably.

  Therefore, according to the radio communication system having the radio base station 10 according to the third embodiment, the transmission power of each radio terminal 20 can be appropriately controlled, and the radio link between each radio terminal 20 and the radio base station 10 can be controlled. It can be maintained stably. In addition, since the radio base station 10 can know the propagation loss of all radio resource blocks at every predetermined timing, the radio base station 10 follows the temporal change in the radio state, and performs the downlink modulation scheme, antenna beamforming, etc. It is also possible to control.

  Furthermore, in FIG. 6, the control unit 15 can also compare Ph and Phref after determining the communication type by reversing the order of the processes of steps S36 and S37 and S40. That is, in step S36, the control unit 15 determines whether or not the communication type of the wireless terminal 20 is a communication type T1 that requires real-time characteristics, and in each of steps S37 and S40, each wireless terminal 20 On the other hand, the difference information Ph of the wireless terminal 20 and the wireless resource allocation reference Phref set based on the moving speed acquired by the moving speed acquisition unit 14 can be compared. As a result, for example, in a certain radio terminal 20, if the communication type is T1 and Ph ≧ Phref, the control unit 15 allocates a radio resource having a large propagation loss in the group A to the communication terminal 20. .

  In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible. For example, in the above embodiment, the radio resource blocks are classified into two radio resource groups. However, a plurality of thresholds can be set for propagation loss, and the radio resource blocks can be classified into three or more radio resource groups. Similarly, the communication type is not limited to two, and can be classified into three or more. In this way, if the radio resource group is classified into three or more or the communication type is classified into three or more, the radio resource block for each radio terminal is changed to the difference information Ph of the radio terminal, the moving speed, and More appropriate and efficient scheduling can be performed according to the communication type.

  In addition, as a method of acquiring the movement speed in the movement speed acquisition unit, for example, the movement speed acquisition unit obtains the position information and time information of the wireless terminal acquired by the GPS provided in the wireless terminal at a predetermined timing. And the wireless base station calculates the moving speed from these pieces of information.

  In addition, the present invention not only obtains the moving speed by performing processing on the radio base station side as described above, but also determines the moving speed of the own terminal based on the positional information for each predetermined time obtained by GPS or the like, for example. When detecting and transmitting the difference information Ph of the current transmission power with respect to the maximum transmission power to the radio base station, the moving speed information of the terminal may be transmitted together.

  In addition, the present invention is not limited to LTE, WiMAX (Worldwide Interoperability for Microwave Access), UMB (Ultra Mobile Broadband), Next Generation PHS (Personal Handy-phone System), IMT-Advanced, etc. The present invention can be widely applied to a wireless communication system in which resources are allocated and wireless communication is performed.

DESCRIPTION OF SYMBOLS 10 Radio base station 11 Wireless communication part 12 Propagation loss measurement part 13 Ph acquisition part 14 Movement speed acquisition part 15 Control part 20 Wireless terminal 21 Wireless communication part 22 Ph calculation part 23 Control part 30 Wireless base station 31 Communication classification information acquisition part

Claims (9)

In a radio base station that performs radio communication by assigning different radio resources to a plurality of radio terminals,
A measurement unit that measures a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
A difference information acquisition unit for acquiring difference information of a current transmission power with respect to a maximum transmission power transmitted from each of the plurality of wireless terminals;
A moving speed acquisition unit that acquires the moving speed of each of the plurality of wireless terminals;
A radio resource allocation standard corresponding to the moving speed acquired by the moving speed acquisition unit is set for each of the radio terminals, the radio resource allocation standard, the propagation loss measured by the measuring unit, and the difference information report acquisition based on the obtained difference information in parts, Bei example a control unit for controlling the allocation of radio resources for each of said plurality of wireless terminals,
The controller is
Propagation measured by the measurement unit for the radio terminal in which the difference information acquired by the difference information acquisition unit is less than a first threshold indicating the radio resource allocation criterion set for each radio terminal. Assigning the radio resource having a relatively small loss to the radio terminal in which the difference information acquired by the difference information acquisition unit is equal to or higher than a first threshold indicating the radio resource allocation criteria set in each radio terminal Then , a radio base station , wherein a resource having a relatively large propagation loss measured by the measurement unit is allocated .   The radio base station according to claim 1, wherein the moving speed acquisition unit acquires the moving speed of the radio terminal based on a received signal from the radio terminal. A communication type information acquisition unit for acquiring communication type information indicating the communication type of each of the plurality of wireless terminals;
The controller is
The wireless resource allocation criteria set for each of the wireless terminals , the propagation loss measured by the measurement unit, the difference information acquired by the difference information acquisition unit, and the communication type information acquired by the communication type information acquisition unit based on the radio base station according to claim 1 or 2, wherein controlling the allocation of radio resources, wherein the for each of the plurality of wireless terminals. The controller is
Based on the propagation loss in each radio resource measured by the measurement unit, classify the plurality of radio resources into at least two radio resource groups,
Based on the wireless resource allocation criteria set for each of the wireless terminals, the difference information acquired by the difference information acquisition unit, and the communication type information acquired by the communication type information acquisition unit, the plurality of wireless terminals The radio base station according to claim 3 , wherein control is performed so that radio resources of the corresponding radio resource group are allocated to each. The controller is
Classifying the plurality of radio resources into at least two or more radio resource groups based on a comparison between a propagation loss in each radio resource measured by the measurement unit and a preset second threshold;
The radio base station according to claim 4 . The controller is
For each of the radio terminals, after determining the radio resource group to which radio resources are allocated based on the radio resource allocation criteria set for each of the radio terminals and the difference information acquired by the difference information acquisition unit, Based on the communication type information acquired by the communication type information acquisition unit, control is performed to allocate a radio resource having a relatively large or small propagation loss measured by the measurement unit within the determined radio resource group. ,
The radio base station according to claim 4 or 5 , wherein The controller is
After determining the radio resource group to which radio resources are allocated to the radio terminals based on the communication type information acquired by the communication type information acquisition unit, the radio resource allocation criteria set for each of the radio terminals Based on the difference information acquired by the difference information acquisition unit, control is performed so as to allocate a radio resource having a relatively large or small propagation loss measured by the measurement unit within the determined radio resource group. ,
The radio base station according to claim 4 or 5 , wherein A radio resource allocation method in a radio base station that performs radio communication by allocating different radio resources to a plurality of radio terminals,
Measuring a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
Obtaining difference information of current transmission power with respect to maximum transmission power transmitted from each of the plurality of wireless terminals;
Obtaining a moving speed of each of the plurality of wireless terminals;
A radio resource allocation criterion according to the acquired moving speed is set for each of the radio terminals, and the plurality of the plurality of radio resource allocation criteria based on the radio resource allocation criterion, the measured propagation loss, and the acquired difference information and controlling the allocation of radio resources for each of the wireless terminals, only including,
For the wireless terminal in which the acquired difference information is less than a first threshold value indicating the wireless resource allocation criterion set in each wireless terminal, the measured propagation loss is relatively small. A resource is allocated, and the measured propagation loss is relatively for the wireless terminal whose acquired difference information is equal to or higher than a first threshold value indicating the wireless resource allocation criterion set in each wireless terminal. A radio resource allocation method characterized by allocating a large resource . In a wireless communication system in which different wireless resources are allocated to a plurality of wireless terminals by a wireless base station, and wireless communication is performed between the wireless base station and the plurality of wireless terminals,
Each of the plurality of wireless terminals is
A calculation unit that calculates a difference between the current transmission power and the maximum transmission power that can be transmitted by the wireless terminal, and outputs difference information;
A transmission unit for transmitting the difference information output from the calculation unit to the radio base station,
The radio base station is
A measurement unit that measures a propagation loss in the radio resources allocated to the plurality of radio terminals at each predetermined timing; and
A difference information acquisition unit for acquiring difference information of a current transmission power with respect to a maximum transmission power transmitted from each of the plurality of wireless terminals;
A moving speed acquisition unit that acquires the moving speed of each of the plurality of wireless terminals;
A radio resource allocation standard corresponding to the moving speed acquired by the moving speed acquisition unit is set for each of the radio terminals, the radio resource allocation standard, the propagation loss measured by the measuring unit, and the difference information report acquisition A control unit that controls allocation of the radio resource to each of the plurality of radio terminals based on the difference information acquired by the unit, and
The controller is
Propagation measured by the measurement unit for the radio terminal in which the difference information acquired by the difference information acquisition unit is less than a first threshold indicating the radio resource allocation criterion set for each radio terminal. Assigning the radio resource having a relatively small loss to the radio terminal in which the difference information acquired by the difference information acquisition unit is equal to or higher than a first threshold indicating the radio resource allocation criteria set in each radio terminal Then , a radio communication system , wherein a resource having a relatively large propagation loss measured by the measurement unit is allocated .

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