JP2003304567A - Scheduling method and wireless base station apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scheduling method and a wireless base station apparatus capable of enhancing the throughput of uplink transmission. <P>SOLUTION: A transmission available reference determining section 105 grasps the presence of communication terminals existing in the vicinity of an edge of adjacent cells on the basis of information from a host network. A scheduling section 107 performs scheduling such that the communication terminals existing in the vicinity of cell edges adjacent to each other make no uplink transmission at the same time. The wireless base station apparatus transmits the scheduling information to the communication terminals and the communication terminals perform the uplink transmission on the basis of the scheduling information. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scheduling method and a radio base station apparatus for carrying out uplink scheduling.

[0002]

2. Description of the Related Art Conventionally, as a packet transmission method, HSDPA (High Speed Downlink Pas) has been used for the purpose of speeding up the downstream peak transmission rate, low transmission delay, and high throughput.
A method called cket access) is under consideration. And as a technology to support HSDPA, 3GPP (3rd
Generation Partnership Project) TR25.848 "
Physical layer aspects of UTRA High Speed Downlink
Packet Access "is proposed.

By the way, starting from this HSDPA system,
Techniques for enabling downlink high-speed packet communication have been developed also in systems such as DR (High Data Rate). An important technique among them is a scheduling technique that determines which communication terminal is currently assigned a downlink channel. Since this scheduling has a great influence on the throughput of wireless transmission, various measures have been taken.

The methods currently considered as the scheduling technology are roughly classified into Best CIR.
(Wanted-to-interference wave power ratio) method, Round Robi
n method (hereinafter referred to as RR method), Proportio
There are three types of nal fairness (hereinafter referred to as PF method).

The Best CIR method has the highest CIR.
Is a method of selecting a terminal that indicates that the throughput as a base station is high. However, communication terminals near the base station are often assigned packet transmission, which is good.
A communication terminal located at the cell edge has a drawback that packet transmission is not easily assigned.

[0006] The RR method is a method in which packet transmission is randomly assigned to all communication terminals, and has a drawback that fairness can be maintained but throughput cannot be increased so much.

In the PF method, the average value (or + α) of CIR is measured for each terminal and the CI currently higher than that value is measured.
With the method of allocating to the communication terminal indicating R, fairness can be maintained and throughput can be improved to some extent.

As described above, each method has advantages and disadvantages, and at present, it is considered to use them in combination.

[0009]

However, in the system that realizes each of the above-mentioned scheduling methods, only downlink scheduling is considered, and uplink scheduling is hardly considered.

That is, as shown in FIG. 8, in the case of downlink transmission, since the transmission is from the base station, the radio waves reach the current cell (sector) configuration almost equally.
On the other hand, in the case of uplink transmission, the positions of the communication terminals are different. Therefore, when the communication terminals at the cell edge belonging to NodeB # 1 are assigned channels to transmit, they are within the cells of different base stations. Existing in NodeB #
It will also interfere with # 2 and # 3. By the way,
In FIG. 8, NodeB represents the installation position of the base station,
In FIG. 8, each base station divides one cell into three sectors (hexagons in the figure represent sectors).

In the current scheduling of upstream transmission,
Since scheduling taking into consideration interference with these other cells is not performed, the throughput of uplink transmission may be extremely reduced in some cases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a scheduling method and a radio base station apparatus capable of improving the throughput of uplink transmission.

[0013]

In order to solve such a problem, the present invention has the following constitution.

(1) The scheduling method of the present invention is
Uplink transmission scheduling is performed in which communication terminals that belong to different cells and exist near cell edges adjacent to each other do not perform uplink transmission at the same time.

According to this method, since communication terminals existing at cell edges of different cells do not perform uplink transmission at the same time, it is possible to reduce interference between other cells due to uplink transmission, and as a result, uplink transmission. Throughput can be improved.

(2) The scheduling method of the present invention is
A scheduling method for forming a plurality of sectors, and performing scheduling for uplink transmission to a plurality of communication terminals existing in each sector, the reception quality of a communication terminal belonging to a certain sector in the belonging sector. In addition to seeking the effect on other sectors during transmission,
Scheduling is performed within a sector in consideration of the influence on other sectors.

According to this method, since it is possible to prevent communication terminals from causing simultaneous uplink transmissions that would greatly interfere with other sectors, it is possible to reduce interference between sectors due to uplink transmissions. As a result, the throughput of uplink transmission can be improved.

(3) The radio base station apparatus of the present invention is a radio base station apparatus that performs scheduling for uplink transmission to a plurality of communication terminals existing in a cell, and exists near the edges of adjacent cells. Means for grasping the existence of the communication terminal, a scheduling means for performing scheduling so as not to perform uplink transmission at the same time between communication terminals existing in the vicinity of cell edges adjacent to each other, and a transmitting means for transmitting scheduling data to the communication terminal , Is adopted.

According to this configuration, communication terminals existing at cell edges of different cells do not perform uplink transmission at the same time, so that it is possible to reduce interference between other cells due to uplink transmission, and as a result, uplink transmission. Throughput can be improved.

(4) A radio base station apparatus of the present invention is a radio base station apparatus that performs scheduling for uplink transmission to a plurality of communication terminals existing in a cell, and has a line quality with each communication terminal. Line quality detection means for detecting
A first scheduling means for deciding the uplink transmission order in order of good channel quality, a second scheduling means for deciding the uplink transmission order at random, and a time during which the uplink transmission is permitted to a communication terminal near the cell edge of another adjacent cell. Alternatively, a selecting means for selecting a transmission order determined by the first scheduling means during a time when there is a high possibility that the uplink transmission is performed, and a selecting means for selecting a transmission order determined by the second scheduling means for other times. , Is adopted.

According to this configuration, during the time when the transmission order is selected by the first scheduling means, since the communication terminal having good line quality close to the base station is assigned the transmission with high priority, the scheduling having good throughput is performed. Is done. On the other hand, during the period in which the transmission order is selected by the second scheduling means, transmission is assigned to all communication terminals with a uniform probability, so fairness is maintained. However, when the second scheduling means is selected, transmission is more likely to be assigned to the communication terminal near the cell edge than when the first scheduling means is selected. Considering this, the selection means
The time when the uplink transmission is permitted to the communication terminal near the cell edge of another adjacent cell or the time when the uplink transmission is likely to be performed is not the first scheduling means but the first scheduling means.
Select the scheduling means of. As a result, it is possible to reduce the possibility that uplink transmission will be performed at the same time as a communication terminal of another cell near the cell edge, and to achieve both fairness of scheduling and throughput.

(5) The radio base station apparatus of the present invention is a radio base station apparatus that performs scheduling regarding uplink transmission to a plurality of communication terminals existing in a cell, and has a line quality with each communication terminal. Line quality detection means for detecting
The same scheduling as the second scheduling means is performed in a first scheduling means that determines the uplink transmission order in order of good channel quality, a second scheduling means that randomly determines the uplink transmission order, and another cell adjacent to the second scheduling means. The period has a configuration including a selection unit that selects the transmission order determined by the first scheduling unit.

According to this structure, since the transmission order by the second scheduling means is not selected between adjacent other cells at the same time, uplink transmission can be performed at the same time as the communication terminal of the other cell near the cell edge. Sex becomes low. As a result, it becomes possible to achieve both fairness of scheduling and throughput.

(6) A radio base station apparatus according to the present invention is a radio base station apparatus that performs scheduling regarding uplink transmission to a plurality of communication terminals existing in a cell, and receives signals from the communication terminals in a directional manner. And a scheduling means for scheduling uplink transmission in a directional range such that directional reception directions do not overlap at the same time between other cells adjacent to each other.

According to this structure, the arrival directions of the signals from the communication terminals selected for each cell are relatively distant from each other, so that the directional receiving means suppresses the interference from the communication terminals other than the own cell. It will be easier.

(7) The radio base station apparatus of the present invention is a radio base station apparatus that performs scheduling regarding uplink transmission to a plurality of communication terminals existing in a sector, and receives signals from the communication terminals in a directional manner. And a scheduling means for scheduling uplink transmission so that communication terminals existing between other sectors whose directivity directions are adjacent to each other do not perform uplink transmission at the same time.

With this structure, communication terminals existing in sectors in the directivity directions adjacent to each other do not perform uplink transmission at the same time, and therefore interference during uplink transmission can be reduced.

(8) The radio base station apparatus of the present invention is (4)
In addition to any one of (6) to (6), means for recognizing the existence of a communication terminal existing near the cell edge of the adjacent cell is further provided, and the scheduling process is performed only when the communication terminal exists near the cell edge of the adjacent cell. Take the configuration.

According to this configuration, when there is no communication terminal near the cell edge of the adjacent cell, a desired scheduling process can be performed without being limited to the above-mentioned (4) to (6) scheduling process, so that the actual uplink is performed. The scheduling method is limited only when transmission interference is likely to occur. As a result, diversity of scheduling can be maintained.

(9) The radio base station apparatus of the present invention is a radio base station apparatus that forms a plurality of sectors and performs scheduling for uplink transmission to a plurality of communication terminals existing in each sector. , The line quality acquisition means for acquiring the line quality for each sector for communication terminals, the priority calculation means for ranking the communication terminals for each sector by increasing the priority as the line quality is better, and the line quality for other sectors. For a good communication terminal, regardless of the priority by the priority calculation means, the communication terminal is provided with a scheduling means for performing scheduling in which the communication terminal in another sector is not allowed to perform uplink transmission during the time when the communication terminal is permitted to perform uplink transmission. Take the composition.

According to this configuration, it is possible to prevent communication terminals that exert a large interference to other sectors from performing uplink transmission at the same time, so that it is possible to reduce interference between sectors due to uplink transmission. As a result, the throughput of uplink transmission can be improved.

(10) The radio base station system of the present invention is
First and second radio base station devices that form cells adjacent to each other and perform uplink transmission scheduling of communication terminals in the own cell, and a host network device that connects the radio base station devices are provided. The second wireless base station device refers to the scheduling information of the other party received from the higher-order network device, and performs uplink transmission to the communication terminal existing near the cell edge of the other party and the communication terminal existing near its own cell edge at the same time. A configuration is adopted in which uplink transmission scheduling that does not perform the above is performed.

According to this structure, since the communication terminals at the cell edge do not perform uplink transmission at the same time, interference between other cells due to uplink transmission can be reduced, and as a result, the throughput of uplink transmission is improved. obtain.

(11) The host network device of the radio base station device of the present invention is connected to a plurality of radio base station devices,
Among the wireless base station devices forming adjacent cells of the wireless base station devices, it is possible to allocate uplink transmission to communication terminals existing at the cell edge only to one or a plurality of specific wireless base station devices. Allow, take composition.

According to this configuration, the radio base station apparatuses adjacent to each other connected to the host network apparatus do not perform scheduling such that communication terminals at the cell edge of the adjacent cell simultaneously perform uplink transmission. As a result, interference between other cells due to uplink transmission can be reduced, and uplink transmission throughput can be improved.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is to perform uplink transmission scheduling so that communication terminals existing in the vicinity of cell edges adjacent to each other are not allowed to perform uplink transmission at the same time.

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

(Embodiment 1) In FIG. 1, reference numeral 100 generally indicates the configuration of a radio base station apparatus according to Embodiment 1 of the present invention. The wireless base station device 100 includes an antenna 10
The reception signal received at 1 is input to the demodulation unit 103 of the reception signal processing unit SP via the transmission / reception duplexer 102 that separates the reception signal and the transmission signal. Actually, the reception signal processing unit SP has other processing units such as a despreading unit in addition to the demodulation unit 103, but only the demodulation unit 103 is shown here for the sake of simplifying the description. Further, the reception signal processing units SP are provided by the number of communication terminals (MS) that are communication partners.

Demodulation section 103 demodulates a CIR (Carrier to Interference Ratio) sent from the communication terminal and sends it to priority calculation section 104. Priority calculation unit 10
In step 4, the communication terminal having a higher CIR has a higher priority and is prioritized.

The transmissibility criterion determining section 105 is, for example, an RN.
Based on the transmission permission information from a higher-level network such as C (Radio Network Controller), it is determined whether or not the communication terminal near the cell edge of the own cell can perform uplink transmission.

Here, the processing of the upper network will be briefly described. The upper network permits only one or a specific plurality of cells from a plurality of adjacent cells to allocate the uplink transmission to a communication terminal that influences other cells existing at the cell edge. Then, the other cells are not permitted and the wireless base station apparatus is notified of this.

Although the transmission permission information is received from the upper network here, the point is that the radio base station apparatus 100 can grasp the existence of communication terminals existing near the edge of the adjacent cell and the uplink transmission schedule. Good.

The transmission-desired terminal information acquisition unit 106 obtains the uplink transmission-desired information from each communication terminal obtained by the demodulation unit 103, and thereby grasps which communication terminal currently desires the uplink transmission. To do.

The scheduling section 107 recognizes whether or not it is possible to select a terminal which is currently in a poor communication state, that is, a communication terminal which is highly likely to be at the cell edge, based on the information determined by the transmittability criterion determining section 105, and Schedule based on the result. For example, when it is permitted to select a communication terminal on the cell edge, scheduling is performed based on the priority calculated by the priority calculation unit 104 as usual, or a communication terminal existing on the cell edge is prioritized. Schedule to select. On the other hand, when the communication terminal existing at the cell edge is not permitted to transmit the uplink, the communication terminal at the cell edge does not select (that is, permit the uplink transmission). Incidentally, the communication terminal at the cell edge is the demodulation unit 103.
It should be recognized based on the CIR from.

Scheduling result information generator 108
Makes the scheduling information obtained by the scheduling unit 107 correspond to each communication terminal, and generates information notifying each communication terminal at which transmission timing. Scheduling information modulator / encoder 109
Performs a modulation and coding process on the scheduling information, and transmits this to the transmission / reception duplexer 102 and the antenna 101.
To the communication terminal via.

In the above configuration, the radio base station device 10
In the case of 0, the priority calculation unit 104 calculates the priorities of uplink transmission in descending order of the line quality based on the information indicating the line quality such as CIR reported from the communication terminal (that is, Best).
The priority is calculated by the CIR method).

Further, the radio base station apparatus 100 acquires transmission permission information from the upper network indicating whether or not the transmission permission may be given to the communication terminal near the cell edge from the higher level network, and the transmission permission reference determining unit 105 determines whether or not the cell edge near the cell edge of the own cell. It is determined whether the uplink transmission schedule can be assigned to the communication terminal.

In the scheduling unit 107, the priority from the priority calculation unit 104 and the desired terminal information acquisition unit 1 are transmitted.
Uplink transmission scheduling of the communication terminal of the own cell is performed based on the uplink transmission request terminal information from 06 and the transmission permission information from the transmittable criterion determination unit 105.

Scheduling section 107 performs scheduling so that communication terminals near cell edges adjacent to each other do not simultaneously perform uplink transmission. For example, radio base station apparatus 100 is installed in NodeB # 1 in FIG. 8, communication terminal MS1 exists near the cell edge of its own cell, and another communication terminal exists at the cell edge of another cell near this communication terminal MS1. , The communication terminal MS1 and the communication terminal MS1 do not perform uplink transmission at the same time.

As a result, since the communication terminals at the cell edge do not simultaneously perform uplink transmission, it is possible to reduce interference between other cells due to uplink transmission. As a result, the throughput of uplink transmission can be improved.

Thus, according to this embodiment, it is possible to improve the throughput of uplink transmission by performing scheduling so that communication terminals existing in cell edges adjacent to each other do not simultaneously perform uplink transmission.

In the above embodiment, the case where CIR is used as the channel quality between the radio base station apparatus and the communication terminal has been described, but the present invention is not limited to this, and RSCP is also used.
(Received Signal Code Power) or path loss may be used. This also applies to the embodiments described later.

(Embodiment 2) In this embodiment, when the best CIR method and the Round Robin method (RR method) which are existing scheduling techniques are applied to the present invention, these methods are effectively utilized. A method of achieving both throughput and fairness will be described.

In FIG. 2 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, radio base station apparatus 200 of this embodiment is shown.
Is the Best CIR scheduling unit 201 and R.
round Robin (RR) scheduling unit 20
Have two.

Best CIR Scheduling Unit 20
In the first example, the priority calculation unit 104 inputs priority information arranged in descending order of CIR, and the desired transmission terminal information acquisition unit 106 inputs upstream transmission request information. Scheduling is performed by ordering from the best order. The RR scheduling unit 204 inputs the uplink transmission desired information from the transmission desired terminal information acquisition unit 106 and performs scheduling by randomly ordering the communication terminals that desire the uplink transmission regardless of the channel quality.

The Round Robin (RR) schedulable time determination unit 203 includes uplink transmission schedule information in another cell adjacent to the higher network and the first embodiment.
Enter the transmission permission information described in. In the case of this embodiment, at which timing in another adjacent cell R
Inputs information on whether to perform uplink transmission based on R-scheduling. Then, the RR scheduling available time determination unit 203 determines a time during which uplink transmission based on RR scheduling is not performed in adjacent other cells as the RR scheduling available time, and sends the determined available time to the scheduling method selection unit 204. .

The scheduling section 204 selects and outputs the output of the RR scheduling section 202 during the time when the RR scheduling possible time determining section 203 enables the RR scheduling. On the other hand, the best CIR scheduling unit 201 operates during the time when it is determined that the RR scheme cannot be scheduled.
Select the output of and output.

In the above-mentioned configuration, first, when the communication terminal wants to perform uplink transmission, the radio base station device 2
00 is notified. The information is demodulated by the demodulation unit 103 and then stored in the desired transmission terminal information acquisition unit 106. The information is the part that performs scheduling, B
est It is sent to the CIR scheduling unit 201 and the RR scheduling unit 202, and scheduling is performed by each method.

Specifically, the Best CIR scheduling unit 201 preferentially selects communication terminals with good channel quality. That is, a communication terminal in a short distance from the wireless base station device 200 is selected. On the other hand, there is a possibility that the RR scheduling section 202 may select a terminal existing at the cell edge and having poor channel quality.

RR scheduling available time determination unit 20
In 3, the timing to use the result of RR scheduling is determined. At this time, any information may be used as the information for determining the timing as long as the timing does not overlap the adjacent cell. For example, it may be determined in a fixed cycle when the wireless base station device is installed, or may be controlled by the host network as described above.

In other words, R is the time during which uplink transmission based on RR-scheduling is not performed in adjacent other cells.
The uplink transmission based on the scheduling of the R scheme and the uplink transmission based on the scheduling of the Best CIR scheme may be performed during the time when the uplink transmission based on the scheduling of the RR scheme is performed in another adjacent cell.

As a result, it is possible to suppress interference between adjacent cells in upstream transmission and to achieve both throughput and fairness.

The reason why one of the adjacent cells performs the uplink transmission based on the RR scheme scheduling and the other performs the uplink transmission based on the Best CIR scheme scheduling will be described.

In the Best CIR method, since uplink transmission is permitted in order from the communication terminal with good channel quality, it becomes difficult to select communication terminals near the cell edge, and there is a possibility that communication terminals existing near adjacent cell edges will simultaneously perform uplink transmission. Will be lower. As a result, the interference due to uplink transmission can be almost ignored. Moreover, since the Best CIR method is selected, the throughput at this time is improved.

On the other hand, in the RR system, since the uplink transmission is permitted at random, the communication terminals near the cell edge are also fairly selected, but the communication terminals near the cell edge are more likely to be selected than in the Best CIR system. Therefore, when the RR method is used also in the adjacent cells, the uplink transmission interference cannot be ignored between the adjacent cells.

Taking these into consideration, in order to suppress interference between adjacent cells in uplink transmission and to achieve both throughput and fairness, one of the adjacent cells is uplink transmission based on RR scheduling. While performing the above, it was considered to be most effective for the other to perform uplink transmission based on the Best CIR scheme scheduling.

In the above-described embodiment, the Best CIR system is selected during the period when the adjacent other cell selects the RR system, and the RR system is selected during the period when the adjacent other cell selects the Best CIR system. Although the case has been described above, the present invention is not limited to this, and when there is a communication terminal that is scheduled for uplink transmission in the vicinity of the cell edge of another adjacent cell, the Best CIR scheme is selected and the other adjacent cell is selected. Even if the RR method is selected when there is no communication terminal scheduled for uplink transmission in the vicinity of the cell edge, it is possible to suppress interference between adjacent cells in uplink transmission and achieve both throughput and fairness. .

During the period when the RR system is permitted, B
There is no problem even if scheduling is performed based on the est CIR method. In other words, the problem is when the RR method is selected between adjacent cells, so other combinations can be arbitrarily selected.

Further, when the PF method which may select the communication terminal near the cell edge is applied instead of the RR method, the same effect as that of the above-described embodiment can be obtained.

(Embodiment 3) In this embodiment, when the adaptive array antenna (hereinafter referred to as AAA) technology is applied to the present invention by the existing technology, this AAA technology is effectively utilized. Thus, a method of further improving the throughput of uplink transmission will be described.

In FIG. 3 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, radio base station apparatus 300 of this embodiment
Has a plurality of antennas 101, 301, 302, 303, and the received signals received by the plurality of antennas 101, 301, 302, 303 are AAA reception provided in the reception signal processing unit SP via the transmission / reception duplexer 102. It is input to the control unit 304.

The AAA reception control section 304 performs AAA processing, which is a known technique such as a weight vector calculation algorithm and a signal parameter estimation algorithm, to estimate the arrival direction of the upstream transmission signal and to perform array combining. Then, the AAA reception control unit 304 sends the estimated arrival direction of the signal from each communication terminal to the transmittable direction terminal determination unit 306.

The transmittable direction terminal determining unit 306 determines that the AAA
Based on the arrival direction from the reception control unit 304 and the information from the transmittable direction determination unit 305, a communication terminal that can perform uplink transmission is determined. Here, the transmittable direction determining unit 305 receives the transmittable direction information from the upper network, and transmits this information to the transmittable direction terminal determining unit 306.
Send to.

The scheduling unit 307 determines the decision information from the transmittable direction terminal determination unit 306, the uplink transmission desired terminal information from the transmission desired terminal information acquisition unit 106, the priority information from the priority calculation unit 104, and the demodulation unit 103. The CI
Uplink transmission is scheduled based on R.

In the above configuration, the radio base station device 30
The 0-possible transmission direction determination unit 305 receives a direction (or information given in advance) in which upstream transmission is possible from the upper network. The direction in which this uplink transmission is possible is the directional direction shown by the shaded pattern in FIG. That is, for example, when the wireless base station device 300 is installed in the cell 1, the directivity directions DR1, DR2, and DR3 are the uplink transmittable directions.

This directivity direction DR1, DR2, DR3
As is clear from FIG. 4, in the other direct cells (cell 2 and cell 3) adjacent to each other, uplink transmission is not permitted in this directivity direction. As described above, in this embodiment, uplink transmission is permitted to communication terminals whose AAA directional reception directions do not overlap between other cells adjacent to each other. Incidentally, the direction in which uplink transmission is permitted in FIG. 4 is changed every predetermined period, which enables uplink transmission in all directivity directions in a cell in a certain period.

In radio base station apparatus 300, transmittable direction terminal determining section 306 uses uplink transmittable direction from transmittable direction determining section 305 and arrival direction information of each communication terminal from AAA reception control section 304. Then, the terminal capable of uplink transmission is grasped. At this time, the position information acquired by GPS or the like may be transmitted from the communication terminal instead of the result of the arrival direction estimation and used.

Next, radio base station apparatus 300 performs scheduling for this transmittable terminal in scheduling section 307.

As a result, only the communication terminals having the directivity directions shown by the shaded pattern in FIG. 4 will perform uplink transmission at that time, so the arrival directions of the communication terminals selected for each cell are compared. As a result, the wireless base station device 300 can easily suppress interference from communication terminals other than its own cell.

Thus, according to this embodiment, the scheduling of the uplink transmission is performed in the directivity range in which the directivity receiving directions of the adaptive array antennas do not overlap between the other cells adjacent to each other. The interference from communication terminals other than the cell can be reduced, and as a result, the throughput of uplink transmission can be improved.

In this embodiment, the overlapping of directivities between cells has been pointed out, but as shown in FIG. 4, the function of separating directivities between sectors can be transmitted in FIG. By adding to the direction terminal determining unit 306, it is possible to remove the influence between sectors. That is, scheduling of uplink transmission may be performed so that communication terminals existing between other cells whose directivities are adjacent to each other do not perform uplink transmission at the same time.

(Embodiment 4) In this embodiment, a method for reducing interference of uplink transmission between adjacent cells by prohibiting simultaneous transmission of communication terminals near the cell edge in Embodiments 1 to 3 described above. On the other hand, a method for effectively reducing the interference of uplink transmission between sectors will be described.

As shown in FIG. 5, even communication terminals not on the cell edge will interfere with each other by being on the sector edge. Focusing on this point, the inventor of the present invention thought that scheduling in consideration of uplink transmission interference between sectors would further improve the throughput of uplink transmission in addition to the processing of the first to third embodiments. .

In FIG. 6 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, radio base station apparatus 400 of this embodiment
Has a CIR storage unit 401 for each sector. C for each sector
The IR storage unit 401 stores C for each sector measured by the communication terminal.
Save the IR.

In the W-CDMA system, the communication terminal transmits the reception quality of each sector as a Measurement Report to the RNC via the base station in order to support handover. Here, the Me
It is assumed that there is something like an Assurement Report. This makes it possible to estimate how much the signal transmitted from the communication terminal will affect each sector.

In this embodiment, the priority for each sector is calculated with this effect taken into consideration. The scheduling process in this embodiment will be described with reference to FIG. First, the radio base station apparatus 400 uses the priority calculation unit 402 to arrange all communication terminals in a cell in descending order of CIR. At this time, the communication terminal MS3 having the highest CIR is selected as the terminal having the highest priority.

Since the communication terminal MS3 uses the sector # 1 as the main sector, it is possible to perform simultaneous transmission to the remaining sectors # 2 and # 3. Therefore, the communication terminal M having the second highest priority and having the sector # 2 as the main sector
You should select S5 as it should be. However, the communication terminal MS5 has a high CIR even in the sector # 1, and the sector # 5
It can be said that it also affects 1. Therefore, the communication terminal MS5 should not be selected. Since the communication terminal MS1 having the next highest priority has the sector # 3 as the main sector and has no influence on the sector # 1, it is selected as it is. Next, the communication terminals MS9 and MS5 have already been assigned to the sector # 1,
It is not selected because # 3 is filled. Sector # 2
The communication terminal MS8 whose main sector is
Since it does not affect # 2, it will be selected.

As described above, the communication terminals MS are assigned in the order of higher priority in the cell, but more reliable transmission is possible by considering interference with other sectors.

Thus, according to this embodiment, for a communication terminal belonging to a certain sector, in addition to the reception quality in the belonging sector, the influence on other sectors at the time of transmission is determined, and the influence on the other sectors is obtained. By performing scheduling in a sector in consideration of the above, it is possible to prevent communication terminals that may significantly interfere with other sectors from performing uplink transmission at the same time. Can be reduced, and as a result, the throughput of uplink transmission can be improved.

In this embodiment, the case where the number of simultaneous transmissions for each sector is 1 has been described, but the present invention is not limited to this, and scheduling is performed such that a plurality of communication terminals simultaneously transmit depending on resource allocation. You can also In such a case, taking FIG. 7 as an example, sector #
In step 1, resource allocation may be performed so that signals from the communication terminals MS3 and MS5 may be received.

In this embodiment, the transmission order is determined by giving the highest priority to the highest priority. However, the present invention is not limited to this, and the priority of communication terminals that have little influence on other sectors is increased. It is also possible to select the transmission order. That is, taking FIG. 7 as an example, the priority of the communication terminals MS1, MS9, and MS8 that have less influence on other sectors may be increased. Also, both methods may be combined.

Further, the scheduling method of this embodiment may be used simultaneously with the above-described first to third embodiments. This makes it possible to perform scheduling with reduced interference in uplink transmission in both cells and sectors. Actually, it is effective to perform the scheduling described in the fourth embodiment after performing the adjustment between cells described in the first to third embodiments.

The Meas in the W-CDMA system
While the Urement Report is fairly averaged, the CIR used for scheduling is only for the main sector and is often an instantaneous value. Therefore, the influence on each sector can be estimated by using the result of Measurement Report, and the instantaneous CIR can be used only for setting the priority order.

In addition, for example, the CIR
Is higher than that reported in the Measurement Report, the Measurement Report
The value of t is also corrected and made high, and the CIR is Measureme
If lower than reported in nt Report, Me
It is also possible to perform a correction process such as correcting and lowering the value of the maintenance Report.

Further, when the influence on each sector is considered, it is possible to reduce the amount of processing by adding a process such as determining a threshold and considering it if the threshold is exceeded. The threshold setting in this case may be set with a fixed CIR or may be a ratio between terminals performing transmission.

[0096]

As described above, according to the present invention,
By performing uplink transmission scheduling so that communication terminals existing near cell edges adjacent to each other do not perform uplink transmission at the same time, it is possible to reduce interference between other cells due to uplink transmission, and the throughput of uplink transmission. Can improve.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a radio base station apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing the configuration of a radio base station apparatus according to Embodiment 2;

FIG. 3 is a block diagram showing the configuration of a radio base station apparatus according to Embodiment 3;

FIG. 4 is a diagram for explaining the operation of the third embodiment.

FIG. 5 is a diagram for explaining the outline of the fourth embodiment.

FIG. 6 is a block diagram showing the configuration of a radio base station apparatus according to Embodiment 4;

FIG. 7 is a diagram for explaining the operation of the fourth embodiment.

FIG. 8 is a diagram for explaining cells and sectors.

[Explanation of symbols]

100, 200, 300, 400 Radio base station apparatus 104, 402 Priority calculation section 105 Transmittable criterion determination section 106 Desired terminal information acquisition section 107, 307, 403 Scheduling section 201 BEST CIR Scheduling section 202 Round Robin (RR) scheduling Unit 203 Round Robin (RR) Schedulable time determination unit 204 Scheduling scheme selection unit 304 Adaptive array antenna (AAA) reception control unit 305 Transmittable direction determination unit 306 Transmittable direction terminal determination unit 401 Sector-by-sector CIR storage unit

Claims (11)

[Claims] 1. A scheduling method comprising performing uplink transmission scheduling in which communication terminals belonging to different cells and existing in the vicinity of cell edges adjacent to each other do not perform uplink transmission at the same time. 2. A scheduling method for forming a plurality of sectors, and performing scheduling for uplink transmission to a plurality of communication terminals existing in each sector, wherein the communication terminals belong to a certain sector. A scheduling method, characterized in that, in addition to the reception quality in a sector, the influence on other sectors at the time of transmission is obtained, and scheduling in the sector is performed in consideration of the influence on the other sectors. 3. A radio base station device for scheduling uplink transmission for a plurality of communication terminals existing in a cell, and means for recognizing the existence of communication terminals existing in the vicinity of cell edges of adjacent cells. , Scheduling means for performing scheduling so as not to perform uplink transmission at the same time between communication terminals existing in the vicinity of mutually adjacent cell edges, and transmitting means for transmitting scheduling data to the communication terminals. Radio base station device. 4. A radio base station apparatus for scheduling uplink transmissions to a plurality of communication terminals existing in a cell, comprising line quality detecting means for detecting line quality with each communication terminal, and a line. A first scheduling unit that determines the uplink transmission order in order of good quality, a second scheduling unit that randomly determines the uplink transmission order, and a communication terminal near a cell edge of another adjacent cell are permitted to perform the uplink transmission. The transmission order determined by the first scheduling means is selected for the time or the time when uplink transmission is likely to be performed, and the transmission order determined by the second scheduling means is selected for the other times. A radio base station apparatus comprising: a selection unit. 5. A radio base station apparatus for scheduling uplink transmissions to a plurality of communication terminals existing in a cell, comprising line quality detecting means for detecting line quality with each communication terminal, and a line. First scheduling means for determining the upstream transmission order in order of good quality, second scheduling means for randomly determining the upstream transmission order, and scheduling similar to the second scheduling means in adjacent other cells. The radio base station apparatus is characterized by further comprising: selecting means for selecting a transmission order determined by the first scheduling means during a certain period. 6. A radio base station device for scheduling uplink transmission to a plurality of communication terminals existing in a cell, which is adjacent to a directional receiving means for directionally receiving a signal from the communication terminal. A radio base station apparatus comprising: scheduling means for scheduling uplink transmission in a directivity range in which directivity reception directions do not overlap at the same time between other cells. 7. A radio base station apparatus for scheduling uplink transmission to a plurality of communication terminals existing in a sector, and directivity receiving means for directionally receiving signals from the communication terminals, and directivity for each other. A radio base station apparatus, comprising: scheduling means for scheduling uplink transmission so that communication terminals existing between adjacent sectors in different directions do not perform uplink transmission at the same time. 8. The method further comprising means for recognizing the presence of a communication terminal existing near the cell edge of the adjacent cell, and performing the scheduling process only when the communication terminal exists near the cell edge of the adjacent cell. The radio base station apparatus according to any one of claims 4 to 6. 9. A radio base station apparatus which forms a plurality of sectors, and performs scheduling for uplink transmission to a plurality of communication terminals existing in each sector, the channel quality of each sector being set for the communication terminal. The line quality acquisition means for acquiring, the priority calculation means for ranking communication terminals for each sector by increasing the priority as the line quality is better, and the priority calculation for communication terminals with good line quality in other sectors. Irrespective of the priority given by the means, a radio base station apparatus comprising: scheduling means for performing scheduling in which the communication terminal in the other sector is not permitted to perform the uplink transmission during a period in which the communication terminal is permitted to perform the uplink transmission. . 10. First and second wireless base station devices forming adjacent cells and performing uplink transmission scheduling of communication terminals in the own cell, and a host network device connecting the wireless base station devices. The first and second radio base station apparatuses refer to the scheduling information of the other party received from the higher-order network apparatus, and communicate with the communication terminal existing near the cell edge of the other party and the communication terminal existing near its own cell edge. A radio base station system, wherein uplink transmission scheduling is performed so that the terminal does not perform uplink transmission at the same time. 11. A radio base station apparatus connected to a plurality of radio base station apparatuses and forming adjacent cells among the radio base station apparatuses, to one or a plurality of specific radio base station apparatuses. The upper network apparatus of the radio base station apparatus is characterized by permitting uplink transmission to be assigned to a communication terminal that affects other cells existing at a cell edge.