WO2007007662A1 - Control station, base station, slot allocating method, and wireless communication system - Google Patents

Control station, base station, slot allocating method, and wireless communication system Download PDF

Info

Publication number
WO2007007662A1
WO2007007662A1 PCT/JP2006/313557 JP2006313557W WO2007007662A1 WO 2007007662 A1 WO2007007662 A1 WO 2007007662A1 JP 2006313557 W JP2006313557 W JP 2006313557W WO 2007007662 A1 WO2007007662 A1 WO 2007007662A1
Authority
WO
WIPO (PCT)
Prior art keywords
transmission power
slot
base station
station
requested
Prior art date
Application number
PCT/JP2006/313557
Other languages
French (fr)
Japanese (ja)
Inventor
Shoichi Shitara
Original Assignee
Sharp Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sharp Kabushiki Kaisha filed Critical Sharp Kabushiki Kaisha
Priority to JP2007524622A priority Critical patent/JP4740241B2/en
Publication of WO2007007662A1 publication Critical patent/WO2007007662A1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W48/00—Access restriction; Network selection; Access point selection
    • H04W48/16—Discovering, processing access restriction or access information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/12—Access point controller devices

Definitions

  • Control station base station, slot allocation method, and radio communication system
  • the present invention relates to slot assignment control in a wireless communication system in which a plurality of cells are adjacent.
  • a mobile communication system communication is performed by a multiple access method in which a plurality of mobile stations are connected to one base station in a cell and wireless communication is simultaneously performed.
  • a radio wave from a base station in an adjacent cell becomes an interference wave.
  • a communication method for avoiding interference waves is adopted.
  • adjacent base stations avoid interference by using a unique spreading code for each base station, such as a communication system that uses different frequency bands in each cell or a CDMA (Code Division Multiple Access) communication system.
  • Wireless communication system is a unique spreading code for each base station.
  • FIG. 24 is a diagram showing an example of frequency allocation in a radio communication scheme in which radio communication is performed using different frequency bands in adjacent cells.
  • FIG. 24 shows a typical frequency allocation example with a frequency repetition number of 3 in a regular hexagonal cell of a wireless communication system.
  • all frequency bandwidths are equally divided by a fixed bandwidth, and frequency bands are assigned so that the same divided frequency band is not used in adjacent cells.
  • the same frequency is not used in adjacent cells! Therefore, it is possible to prevent deterioration of radio communication quality due to interference waves near the cell edge.
  • the CDMA communication system is a communication system that is resistant to interference because a signal is multiplied by a spreading code that is different for each cell.
  • the communication quality deteriorates when the interference power increases, it is necessary to increase the relative power ratio between the received signal power of the mobile station and the received interference power. Since the increase in transmission power of adjacent base station power causes interference power for mobile stations in its own cell, the transmission rate is set especially for mobile stations near the cell edge where the interference power of adjacent base station power is large. Interference by lowering and increasing gain by spreading I had to increase the resistance to communication and communicate.
  • Non-Patent Document 1 Shiro Sakata, “Wireless Ubiquitous High-Speed Wireless LANZUWBZ3.5G Mobile Phone, Hidekazu System, P. 195-210, 2004
  • the present invention has been made in view of such circumstances, and in a wireless communication system in which a plurality of cells are adjacent, slots are allocated according to the downlink transmission power of the adjacent cells. It is an object to provide a control station, a base station, and a slot allocation method.
  • One aspect of the control station (base station control station) according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots.
  • a control station that manages a plurality of base stations that communicate wirelessly with mobile stations in a cell, and collects downlink transmission power allocated to each slot from the base stations of each of the plurality of cells and
  • a control station acquisition unit that acquires the required transmission power required for downlink communication from a base station of a specific cell, and the downlink transmission power of one or more cells adjacent to the specific cell are added for each slot
  • the interference power calculation unit for calculating the interference power value for each slot, and the interference power value is smaller than the predetermined value.
  • An allocation unit that allocates the requested transmission power to a lot; and a control station notification unit that notifies allocation information that allocates the requested transmission power to a slot to a base station of the specific cell. To do.
  • this control station adds the downlink transmission power of adjacent cells to calculate an interference power value, and allocates the required transmission power required for downlink communication to a slot with a small interference power value.
  • HS DPA High Speed Downlink Packet Access
  • 3GPP 3rd Generation Partnership Project
  • HSDPA uses the TDMA communication method as in the embodiment of the present invention, and assigns each slot in a frame based on CQI (Channel Quality Indication), which is control information indicating the channel state from the mobile station. Do it.
  • CQI Channel Quality Indication
  • the difference from the present invention is that, in HSDPA, the transmission power of each slot is constant and there is no temporal change in the interference power in adjacent cells, but the present invention actively controls the transmission power of each slot. Interference applied to adjacent cells is reduced.
  • the difference in operation at the mobile station is that HSDPA needs to return CQI for each slot. In the present invention, information calculated from propagation loss should be returned for each frame (every time scheduling is performed).
  • control station acquisition unit acquires a plurality of requested transmission powers
  • allocation unit has a small interference power value among the plurality of slots. It is characterized by selecting slots in order and assigning multiple required transmission powers to the selected slots in descending order.
  • another aspect of the control station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots to make an intra-cell Control station that manages a plurality of base stations that communicate wirelessly with other mobile stations,
  • the transmission power storage unit that stores the downlink transmission power assigned to each slot in each base station in association with the cell, and the downlink transmission power of one or more cells adjacent to a specific cell are added for each slot.
  • An interference power calculation unit that calculates an interference power value for each slot, a control station acquisition unit that acquires a transmission request for the interference power value from a base station, and the interference power calculation unit that has made the transmission request.
  • a control station notifying unit for notifying the base station of an interference power value calculated by selecting a cell of the base station as the specific cell.
  • the control station calculates the downlink transmission power of an adjacent cell as an interference power value and notifies the base station, thereby providing information on the interference power value to the base station that performs slot allocation. can do.
  • the base station can adaptively allocate slots according to the downlink transmission power of neighboring cells, and can reduce inter-cell interference.
  • One aspect of the base station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells in a base station that performs wireless communication with a mobile station in a cell to be controlled.
  • a receiving unit that receives a request transmission power requested by the mobile station as a downlink transmission power, a base station notification unit that notifies the control station according to claim 1, and the control station
  • a base station acquisition unit that acquires allocation information in which requested transmission power is allocated to a slot; a scheduling unit that associates a mobile station that has requested the requested transmission power with a slot using the allocation information; and the request transmission And a transmitter that notifies the mobile station that has requested power of the slot to which the requested transmission power is allocated.
  • this base station calculates the downlink transmission power of an adjacent cell as an interference power value, and uses the obtained allocation information to obtain the required transmission power required for downlink communication with a small interference power value. You can schedule to slots. As a result, it is possible to adaptively allocate slots according to the downlink transmission power of adjacent cells to reduce inter-cell interference.
  • the receiving unit receives a plurality of request transmission powers
  • the scheduling unit is a predetermined one of the plurality of received request transmission powers. Request transmission power larger than the threshold of the base station, the base station notification unit, the selected request The transmission power is notified.
  • Another aspect of the base station according to the present invention is a radio communication system that uses the same frequency between a plurality of adjacent cells, and is a control target using a frame configured of a plurality of slots. Interference power calculated for each slot by adding the downlink transmission power of one or more cells adjacent to the cell to be controlled for each slot.
  • a base station acquisition unit that acquires a value from a control station, a reception unit that receives a request transmission power requested by the mobile station as a downlink transmission power, and a request transmission that is received in a slot when the acquired interference power value is small.
  • the base station can acquire the interference power value, and can allocate the required transmission power required for downlink communication to a slot with a small interference power value. This makes it possible to adaptively allocate slots according to the downlink transmission power of neighboring cells and reduce inter-cell interference. Also, by allocating slots using the interference power value in the base station, it is possible to reduce the amount of information exchanged between the control station and the base station compared to the slot allocation in the control station. .
  • another aspect of the base station according to the present invention is a wireless communication system using the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots.
  • a base station that performs radio communication with a mobile station in a cell to be controlled and manages other base stations, and collects downlink transmission power allocated to each slot for the cells of other base stations.
  • An interference power calculation unit that calculates an interference power value for each slot, a scheduling unit that allocates the requested transmission power received to a slot with a small interference power value, and the request
  • a transmission unit that notifies a mobile station that has requested transmission power of a slot to which the requested transmission power is allocated. It is characterized by.
  • this base station has a function of collecting the downlink transmission power of each cell and calculating the interference power value, and can allocate the requested transmission power to a slot with a small interference power value.
  • at least one base station has a slot allocating unit using the interference power value, so that at least one base station can adaptively slot according to the downlink transmission power of the adjacent cell. Can be assigned. As a result, it is possible to assign the slot of its own cell to be controlled according to the interference power value.
  • the base station acquisition unit acquires the requested transmission power requested by the mobile station of another cell from the other base station, and calculates the interference power.
  • the unit calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the other cell for each slot, and the scheduling unit determines that the interference power value is An allocation information for allocating the requested transmission power acquired to a small slot is created, and the base station notification unit notifies the created allocation information to the other base station.
  • this base station when this base station acquires other base station power request transmission power, it calculates the interference power value to the cell of the other base station, and requests transmission to a slot with a small interference power value. Power can be allocated. As a result, at least one base station among the plurality of base stations has a slot allocation means using the interference power value, so that at least one base station adaptively responds to the downlink transmission power of the adjacent cell. Slots can be assigned.
  • the scheduling unit selects a slot in order from among a plurality of slots, the interference power value being small, and a plurality of requested transmission powers to the selected slot. Are assigned in order of size.
  • One aspect of a slot allocation method for a control station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots in the cell Control station slot that manages multiple base stations that communicate wirelessly with other mobile stations
  • Receiving a base station power of a specific cell calculating an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot; Assigning the requested transmission power to a slot having a small interference power value V and notifying the allocation information allocating the requested transmission power to the slot to the base station of the specific cell. It is characterized by.
  • the downlink transmission power of an adjacent cell is calculated as an interference power value, and the requested transmission power required for downlink communication is allocated to a slot with a small interference power value.
  • Inter-cell interference can be reduced by adaptively assigning slots according to the downlink transmission power of the cell.
  • One aspect of a slot allocation method for a wireless communication system is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and a plurality of cells in which a mobile station exists are adjacent to each other.
  • the required transmission power required for the downlink communication is less than that of the control station or base station of this wireless communication system, and the downlink transmission power of the adjacent cell is small. Since it is assigned to the slot, it becomes possible to adaptively assign the slot according to the downlink transmission power of the adjacent cell and reduce inter-cell interference. In addition, since the interference power value is calculated using the downlink transmission power of the adjacent cell, slots can be allocated according to the interference power value of the adjacent cell, and interference between cells can be reduced. [0031] (12) In one aspect of the control station according to the present invention, the interference power calculation unit multiplies the downlink transmission power by a coefficient corresponding to an attenuation, and calculates the downlink transmission power multiplied by the coefficient. The addition is performed for each slot.
  • the interference power calculation unit multiplies the downlink transmission power by a coefficient corresponding to an attenuation, and calculates the downlink transmission power multiplied by the coefficient. The addition is performed for each slot.
  • the step of calculating the interference power multiplies the downlink transmission power by a coefficient corresponding to an attenuation amount, and The downlink transmission power multiplied is added for each slot.
  • An aspect of the wireless communication system is a frame in which a plurality of adjacent cells use the same frequency, a plurality of cells in which a mobile station exists are adjacent, and are configured from a plurality of slots.
  • a wireless communication system comprising a control station that manages a plurality of base stations that wirelessly communicate with mobile stations in a cell using a base station of each of the plurality of cells depending on! The station power also collects the downlink transmission power allocated to each slot, and calculates the interference power value based on the downlink transmission power of one or more cells adjacent to a specific cell out of the collected downlink transmission power. Then, the requested transmission power required as the downlink transmission power is obtained from the base station of the specific cell, and the requested transmission power is allocated to the slot having the small interference power value.
  • the required transmission power required for the downlink communication is less than that of the control station or base station of this wireless communication system, and the downlink transmission power of the adjacent cell is small. Since it is assigned to the slot, it becomes possible to adaptively assign the slot according to the downlink transmission power of the adjacent cell and reduce inter-cell interference. In addition, since the interference power value is calculated using the downlink transmission power of the adjacent cell, slots can be allocated according to the interference power value of the adjacent cell, and interference between cells can be reduced. The invention's effect
  • the communication system and system configuration to which the embodiment of the present invention is applied will be described.
  • the basic communication system in the first embodiment of the present invention is a TDMA (Time Division Multiple Access system 3) or FDMA (Frequency Division Multiple Access) system.
  • the TDMA scheme is an access scheme in which the same frequency band is divided into short times when data transmission / reception is performed, and wireless communication is performed by assigning the divided short and time sections to different users. Normally, wireless communication is performed by repeatedly transmitting and receiving a time interval called a frame at a constant cycle.
  • a time slot or TTI Transmission Time Interva This is an access method in which wireless communication is performed between a plurality of mobile stations and a base station at the same time by assigning a short time interval called 1) to a plurality of mobile stations.
  • a plurality of mobile stations when transmitting and receiving data, a plurality of mobile stations simultaneously divide a frequency band obtained by dividing a frame, which is a certain time interval, into a certain bandwidth in a frequency direction called a frequency slot. It is an access method for performing wireless communication using it.
  • FIG. 1 is a diagram illustrating an example of a frame configuration.
  • FIG. 1 (a) shows an example of a general TDMA frame structure.
  • the number of slots is 8.
  • a control slot including information data for notifying all mobile stations such as mobile station allocation information of each slot and modulation scheme and broadcast information is set in the slot at the head of the frame. Traffic data, mobile station specific control information, known information for propagation path estimation, etc. are allocated to other slots and transmitted.
  • FIG. 1 (b) shows an example of a general FDMA frame structure.
  • the number of slots is 12.
  • the control slot including information data for notifying all mobile stations such as slot allocation information, modulation scheme and broadcast information of each mobile station is the first slot. Is set.
  • the position of the control slot is not limited to that.
  • the other slots are assigned traffic data, mobile station specific control information, known information for channel estimation, etc., and are transmitted.
  • FIG. 2 is a diagram showing a configuration example of a radio communication system according to the embodiment of the present invention.
  • This system is a system in which base station control stations (“base station control station” is also referred to as “control station”) 100, base stations 200a to 200d, and mobile stations 300a to 3001 are hierarchically configured.
  • base station control station is also referred to as “control station”
  • base stations 200a to 200d base stations 200a to 200d
  • mobile stations 300a to 3001 are hierarchically configured.
  • base station control station is also referred to as “control station”
  • base stations 200a to 200d base stations
  • mobile stations 300a to 3001 are hierarchically configured.
  • base station control station when there are a plurality of the same constituent elements and they are distinguished from each other, a suffix is added to the code to distinguish each of the plurality of constituent elements.
  • 200b, 200c, and 200d indicate one or more of the base stations when the base station 200 is divided into a plurality of base stations. The same applies
  • Base station control station 100 is connected to a plurality of base stations 200 and controls each base station 200.
  • Each base station 200 is connected to a plurality of mobile stations 300 existing in the cell by wireless communication, and manages the mobile stations.
  • Each mobile station 300 transmits and receives data based on control information from the base station 200.
  • the communication between the base station control station 100 and the base station 200 cannot be performed by either wired communication or wireless communication.
  • the mobile station 300 includes a portable terminal (mobile terminal) that performs wireless communication such as a wireless device and a mobile phone.
  • FIG. 3 is a block diagram illustrating a configuration example of the base station control station of the first embodiment.
  • the base station control station 100 is based on the control station acquisition unit 110 that acquires (receives) control information notified from each base station 200, and the control information notified from each base station 200.
  • a control information processing unit 120 that controls each base station 200; and a control station notification unit 130 that notifies (transmits) the control result controlled by the control information processing unit 120 to each base station 200.
  • the control information includes requested transmission power requested by the mobile station 300 for transmission, downlink transmission power when the base station 200 transmits data to the mobile station 300, and other information exchanged with each base station 200.
  • the control result includes a result of control by the control information processing unit 120, for example, allocation information described later.
  • the control information processing unit 120 includes a transmission power storage unit 121, an interference power calculation unit 122, and an allocation unit 123.
  • transmission power storage section 121 stores transmission power information in which the downlink transmission power assigned to each slot is associated with each cell.
  • the downlink transmission power of each cell is reported to the base station control station 100 from each base station 200 arranged in the cell.
  • the transmission power information is stored in association with a cell identifier that identifies a cell.
  • Allocation section 123 performs slot allocation using transmission power information stored in transmission power storage section 121 and requested transmission power acquired from base station 200.
  • the transmission power storage unit 121 may be an area for temporarily storing transmission power information. For example, it may be a storage area secured only when slot allocation is performed. Therefore, a mechanism for securing a storage area for storing transmission power information is provided. You should be! /
  • Interference power calculation section 122 calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot.
  • the interference power here is the sum of transmission power for each slot considering the distance between each adjacent base station and its own base station, and is different from the interference power received by each mobile station in the cell. .
  • Assigning section 123 uses the interference power value calculated by interference power calculating section 122 to allocate the requested transmission power received to a slot whose interference power value is smaller than a predetermined value.
  • the slots are assigned in order from the smallest (highest) requested transmission power to the slots with the smallest interference power value.
  • Allocation unit 123 creates allocation information in which the requested transmission power is associated with the slot number of the allocated slot.
  • FIG. 4 is a block diagram illustrating a configuration example of the base station according to the first embodiment.
  • the base station 200 includes a base station notifying unit 210 that notifies (transmits) control information such as required transmission power and downlink transmission power to the base station control station 100, and base station control using the control information.
  • a base station acquisition unit 220 that acquires (receives) control results controlled by the control station 100, a transmission unit 230 that transmits wireless data to the mobile station 300, and a reception unit 240 that receives wireless data from the mobile station 300.
  • Mobile station control section 250 that processes information notified from base station control station 100 and each mobile station 300, and wireless data is transmitted / received to / from each mobile station 300 via antenna section 260.
  • the mobile station control processing unit 250 includes a scheduling unit 251 and a power control unit 252.
  • Scheduling section 251 assigns mobile station 300 to each slot.
  • each mobile station 300 is allocated to a slot using allocation information notified from the base station control station 100. Details will be described later.
  • the power control unit 252 controls the downlink transmission power of each slot based on the result of the scheduling unit 251.
  • FIG. 5 is a block diagram illustrating a configuration example of the mobile station according to the first embodiment.
  • the mobile station 300 includes a receiving unit 310 that receives wireless data transmitted from the base station 200, a transmitting unit 320 that transmits wireless data to the base station 200, and an information processing unit 330 that processes the received wireless data. Wireless data is transmitted and received from the antenna unit 340. Furthermore, the mobile station 300 includes a reception power measurement unit 350 that measures the reception power level of radio data transmitted from the base station 200 in the downlink (downlink direction), and propagation path quality information calculated from the measurement result. To the base station 200 through uplink (uplink) wireless communication.
  • the procedure and operation of slot allocation in the first embodiment of the present invention will be described below.
  • the outline of the slot allocation method of the first embodiment is as follows.
  • mobile station 300 installed in each of a plurality of cells, a plurality of base stations 200 controlling mobile stations 300 existing in each cell, and a base station control managing a plurality of base stations 200
  • a wireless communication system composed of station 100 is used.
  • Multiple base stations 200 determine downlink transmission power in consideration of downlink channel quality information received from each mobile station 300, and base station control station 100 receives the determined downlink transmission power.
  • the downlink transmission power of the slot used by each mobile station 300 is adaptively allocated so as to reduce the amount of interference due to radio waves from neighboring cells.
  • the slot to which the base station control station 100 allocates the requested transmission power has a downlink transmission power of a certain value or more in order to reduce the amount of information between the base station control station 100 and the base station 200.
  • Slot allocation is performed only for necessary slots. Performing transmission power allocation work
  • the threshold of requested transmission power is the factor involved in the increase / decrease in the amount of information such as the number of controlled base stations and the number of slots, that is, the amount of information between the base station control station 100 and a plurality of base stations 200. And hope to be determined by information processing ability.
  • the base station 200 allocates a slot to the mobile station 300 that requires a downlink transmission power larger than the threshold using the allocation information notified from the base station control station 100, and other than the allocated slot. Among them, a slot is allocated to a mobile station 300 that requires downlink transmission power equal to or less than a threshold value.
  • Base station 200 schedules data for each mobile station 300 based on the allocation result (allocation information) and transmits radio data. Details of allocation when adaptive slot allocation is performed by the base station control station 100 will be described below.
  • the slot allocation method is applied to a wireless communication system of a mobile phone, and a terminal (mobile terminal) is described as an example of the mobile station 300.
  • the slot configuration according to the first embodiment will be described by taking the slot configuration in the TDMA system shown in FIG. 1 (a) as an example. However, the same effect can be obtained by treating the slots in the frequency direction in the FDMA system as described above as slots in the time axis direction of the TDMA system.
  • the configuration of the wireless communication system is the same as in FIG. [0061]
  • the first embodiment is a system in which each base station 200 is synchronized, that is, a system designed so that the timing at which each base station 200 transmits a frame is the same.
  • a synchronization method using GPS Global Positioning System
  • the description is omitted here.
  • FIG. 6 is a diagram showing a typical example of a cell and terminal arrangement existing in the cell.
  • FIG. 6 shows a case where terminals A to F exist in cell 1.
  • base station 200a is arranged.
  • FIG. 7 is a diagram showing the relative relationship between the magnitudes of the requested transmission powers for the terminals A to F in the cell 1.
  • FIG. 7 shows an example in which the required transmission power of terminal F is the maximum and the required transmission power of terminal D is the minimum.
  • Threshold P is the downlink
  • Threshold P This is a threshold value for determining whether or not the transmission power is set by the base station control station 100.
  • a terminal that requires a downlink transmission power larger than TH sets the downlink transmission power by the base station control station 100.
  • the value of threshold P is the cell size, base station 200,
  • FIG. 8 is a diagram illustrating a frame configuration example used in the first embodiment.
  • the total number of slots is 16, the number of control slots (slot number 0), the number of time slots is 15, and the same frequency band is used in all cells.
  • FIG. 9 is a diagram showing a relationship between a plurality of cells and terminal arrangement.
  • FIG. 9 shows a state in which cell 1 shown in FIG. 6 is adjacent to cell 2 and cell 3.
  • base station 200b and terminals H to N are arranged, and in cell 3, base station 200c and terminals 0 to U are arranged.
  • slots 2 and 3 in FIG. 9 have already been assigned slots by the same method as in the first experimental embodiment of the present invention.
  • FIG. 10 shows the relative relationship between the required transmission power levels for the terminals H to N in the cell 2.
  • FIG. 11 shows the relative relationship between the required transmission power levels for the terminals O to U in the cell 3. It is assumed that the terminals of each cell are in the slot allocation situation as shown in FIGS. FIG.
  • FIG. 12 is a diagram showing the slot allocation status of each terminal H to N in the cell 2
  • FIG. 13 is a diagram showing the slot allocation status of each terminal 0 to U in the cell 3.
  • cell 1 has a specific cell Equivalent to The specific cell is a cell (slot allocation request cell) in which a base station requesting slot allocation exists.
  • FIG. 14 is a sequence diagram showing an example of slot allocation in the first embodiment.
  • FIG. 14 shows a sequence among the base station control station 100, the base station 200, and the mobile station 300.
  • the operation of the mobile station 300 shows the operation of each of the terminals A to G.
  • the mobile station 300 of the cell 1 when the mobile station 300 of the cell 1 is described, it means all of the terminals A to G or one or more terminals.
  • control station acquisition section 110 acquires the base station 200 (here, base stations 200b and 200c) power downlink transmission power. Then, the downlink transmission power for each slot is stored in the transmission power storage unit 121 (step S10). This operation is performed when the downlink transmission power is notified from each base station 200 after cell 2 and cell 3 slot allocation, or before the base station control station 100 performs downlink transmission before cell 1 slot allocation. Implement by collecting power.
  • Each base station 200 periodically transmits control information to the mobile station 300 (step Sl l).
  • each mobile station 300 receives a control signal periodically transmitted from the base station 200.
  • Each mobile station 300 measures the received power level of the received signal (step S 12), and further demodulates the received signal (step S 13), thereby transmitting control information (control signal) transmitted from the base station 200. ) (Step S14).
  • the control information is transmitted from the base station 200 at regular intervals, and the downlink transmission power is set to the power and modulation scheme that can be received even when the mobile station 300 is located near the cell edge. . It is assumed that the control information transmitted in the control slot includes transmission power of the control slot that transmitted the control information and slot allocation information of each mobile station 300.
  • mobile station 300 calculates a propagation loss, which is the amount of radio wave attenuation in the propagation path, from the downlink transmission power and the received power level obtained from the demodulated signal.
  • the equation for calculating the propagation loss is shown below.
  • Propagation loss downlink transmission power received power level (Equation 1)
  • the mobile station 300 derives the required transmission power and the modulation scheme based on the propagation loss obtained from Equation 1 (step S15). A detailed description of the required transmission power and modulation method derivation is omitted.
  • the mobile station 300 notifies the requested transmission power and modulation scheme to the base station 200 through uplink transmission (step S17). At this time, when the mobile station 300 is continuously communicating with the base station 200, the notification method of the requested transmission power is set to a difference value from the power level currently used for downlink transmission with the base station, It is also possible to notify by a bit indicating increase / decrease.
  • the base station 200 obtains the propagation path quality information of each mobile station 300 by notifying the requested transmission power and modulation scheme from the mobile station 300. During this time, the base station 200 transmits data to terminals that have already been allocated (step S16).
  • scheduling section 251 obtains requested transmission power and modulation scheme information, compares the requested transmission power of each mobile station 300 with threshold P, and
  • a mobile station that needs to be scheduled is determined by 100 (step S18). Specifically, the scheduling unit 251 moves that requires a required transmission power larger than the threshold value P.
  • the base station notification unit 210 notifies the base station control station 100 of the number of allocated slots (the number of extracted mobile stations 300) and the respective requested transmission power (step S19).
  • P is a threshold set to the requested transmission power of the mobile station as described above.
  • the mobile station 300 having a large required transmission power needs to set a downlink transmission power corresponding to the mobile station 300 in order to perform good radio communication. Therefore, the radio data transmitted toward a mobile station having a large required transmission power has a large downlink transmission power and a large interference with adjacent cells. Therefore, P is the value for making a decision to distinguish between mobile stations that require downlink transmission power that causes significant interference and those that do not.
  • the amount of information to be notified from base station 200 to base station control station 100 increases.
  • the amount of information with the base station control station can be manipulated by the value.
  • Control station acquisition section 110 of base station control station 100 acquires the number of assigned slots and the requested transmission power from base station 200.
  • interference power calculation section 122 calculates an interference power value
  • allocation section 123 stores information from base station 200 and transmission power storage section 121. Using the transmission power information stored, slot downlink transmission power allocation is performed (step S20).
  • FIG. 15 is a diagram showing a sum of downlink transmission power for each slot of a plurality of cells.
  • cell 2 shows an example in which downlink transmission power is assigned to slot numbers 1-7
  • cell 3 shows an example in which downlink transmission power is assigned to slot numbers 9-15.
  • the interference power calculation unit 122 calculates the interference power value for each slot by adding the downlink transmission power of each base station of the adjacent cell for each slot.
  • the same method can be used to calculate the number of neighboring base stations that cause force interference as shown in the case of handling the transmission waves of the base station power of cell 2 and cell 3 as interference waves.
  • a coefficient corresponding to the amount of attenuation is set in advance for base stations whose interference level is lower than the base station of the nearest cell due to a difference in physical distance from the assigned cell or topographical failure. It is desirable to do. Therefore, in order to add the downlink transmission power of each base station in the adjacent cell for each slot, the downlink transmission power is multiplied by a value corresponding to the attenuation set in advance for each base station. It also includes calculating the transmission power. Also, in this embodiment, there are no slots used simultaneously in cell 2 and cell 3, but if there are slots used simultaneously by two base stations, the downlink transmission power of cell 2 and cell 3 The sum is treated as the total interference power value for that slot.
  • allocating section 123 of base station control station 100 performs slot allocation in the order of the largest required transmission power (step S20).
  • Figure 16 shows a flowchart showing an example of the slot allocation procedure.
  • the control station acquisition unit 110 acquires the requested transmission power from the base station 200 (step S31) and passes it to the allocation unit 123.
  • the allocating unit 123 first determines a slot that requires the largest requested transmission power (step S32).
  • the decision method shall assign the selected slot to the unassigned slot with the smallest sum of downlink transmission powers (ie, interference power values) of adjacent base stations that become interference waves.
  • the mobile station 300 that requested the largest requested transmission power is allocated in order from the slot used, and then the largest, the largest requested transmission power is the sum of the interference power values that are the largest among the slots other than the slots already allocated to the requested transmission power. Is assigned to a slot with a lower value (step S33). That is, the slot power with the large downlink transmission power is also assigned to the slots with the smaller interference power values in order. Then more Continue until there are no more slots to allocate work (step S34).
  • the base station is notified of the transmission power information (assignment information, scheduling information) set for each slot (step S35, step S21 in Fig. 14).
  • base station 200 performs scheduling for mobile station 300 (step S22).
  • the allocation method of each mobile station in the base station 200 will be described according to the flowchart of FIG.
  • FIG. 17 is a flowchart showing an example of a procedure in which the base station assigns a mobile station to each slot.
  • Base station 200 assigns a slot to be used by each mobile station 300 based on assignment information for assigning requested transmission power to each slot acquired from base station control station 100. In the allocation information, the slot number and the requested transmission power are associated. Therefore, the base station 200 associates the mobile station 300 that requested the requested transmission power with the slot number. Also, in the base station 200, the requested transmission power set for the slot is used as the downlink transmission power used in the downlink communication with the mobile station 300.
  • Scheduling unit 251 has a larger required transmission power than threshold P, which is a determination criterion for assigning to base station control station 100 as a first step.
  • Allocation starts from threshold mobile station 300.
  • the scheduling unit 251 of the base station 200 moves in the order of the requested transmission power in the mobile station 300 whose requested transmission power is larger than the threshold value P.
  • Station 300 is assigned a slot, and then, as the second step, the requested transmission power is set to the threshold value P.
  • the requested transmission power is large among the smaller (low) mobile stations 300! /, And slots are allocated to the mobile stations 300 in order. Specifically, the following procedure is performed.
  • scheduling section 251 selects mobile station 300 that has requested the requested transmission power most among unassigned mobile stations 300 (step S41).
  • base station control in the case of mobile station 300 whose requested transmission power is greater than threshold P (Yes in step S42), base station control
  • the slot having the largest required transmission power is allocated from the slots satisfying the required transmission power of the selected mobile station (step S43).
  • the mobile station power having the highest required transmission power is assigned to the slot in which the highest required transmission power is set among the unallocated slots (step S41 to step S43).
  • the requested transmission power requested by the mobile station is determined by the base station control station 100 and notified to the base station 200 as allocation information. Therefore, any slot in the frame is set to the required transmission power !, so the propagation loss is the largest! By selecting, the correspondence with the slot can be taken.
  • the requested transmission power greater than the threshold value P is allocated by the base station control station 100 as a slot.
  • the requested transmission power below the threshold P is slotted by the base station controller 100.
  • the scheduling unit 251 proceeds from the request transmission power not allocated to the slot selected in step S41, in descending order, from the remaining slots other than the slot allocated in the first stage.
  • the slot to be allocated is selected from the slots of (Step S44). The above procedure is repeated until there are no unassigned mobile stations (if step S45 is No, step S41, step S42, and step S44 are repeated).
  • Scheduling section 251 uses the requested transmission power allocated to each slot as the downlink transmission power.
  • the slot allocation result is notified by the transmission unit 230 to the mobile station 300 in the cell through the control slot (step S46, step S24 in FIG. 14).
  • the allocated data is transmitted in the downlink by a desired modulation method (step S47, step S25 in FIG. 14).
  • base station notification section 210 associates the downlink transmission power allocated to each slot with the slot number.
  • the base station control station 100 is notified (step S23 in FIG. 14). However, this procedure does not matter the order of the control information transmission and data transmission procedure to each mobile station 300.
  • the control station acquisition unit 110 acquires the downlink transmission power, and stores the transmission power as transmission power information in which the acquired downlink transmission power is associated with a cell (cell identifier). Write to part 121. Note that the transmission power information is not updated when the transmission power information is notified from the base station 200.
  • FIG. 18 shows the result of slot assignment performed as described above.
  • the upper part of FIG. 18 shows the values of downlink transmission power for each slot for each cell.
  • the lower part is a frame configuration diagram showing the result of slot assignment for cell 1. Specifically, P
  • the base station control station 100 sets the downlink transmission power.
  • Terminal A, terminal B, and terminal F are set.
  • Base station 200a arranged in cell 1 reports to base station control station 100 the number of slots used by terminal A, terminal B, and terminal F and their required transmission power.
  • the base station control station 100 collects the downlink transmission power information from the base stations 200b and 200c of the adjacent cell 2 and cell 3 (the collected transmission power information is transmitted from the transmission power storage unit 121). Read), and the sum for each slot is calculated. For the calculation, a value that corrects the distance between the base station 200a and the base stations 200b and 200c, which are peripheral interference stations, is taken into account. good.
  • request slots are assigned from slot 8, which is the smallest sum.
  • the requested transmission power is assigned to slot 7.
  • the requested transmission power is assigned to slot 6.
  • Allocation information including three slot numbers and power information is notified to base station 200, and base station 200 performs slot allocation for each terminal. Slot allocation at the base station 200a starts with the required transmission power! /, Starting from the terminal, and specifically in the order of the terminals F, A, B, E, C, G, D. The slot assignment is selected from the slots that satisfy the required downlink transmission power of each terminal.
  • the requested transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells.
  • the requested transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells.
  • the requested transmission power is allocated to an unallocated slot in the base station 200. This is based on the assumption that the requested transmission power below the threshold is less affected by interference.
  • This embodiment is different from the first embodiment in that the slot transmission power allocation work is performed by the base station.
  • This embodiment uses the TDMA communication system and the FDMA communication system as in the first embodiment.
  • the description of the TDMA communication system and FDMA communication system used in this embodiment is the same as in Embodiment 1 and is omitted.
  • the system configuration of this embodiment is the same as that shown in FIG.
  • FIG. 19 is a block diagram illustrating a configuration example of the base station control station of the second embodiment.
  • FIG. 20 is a block diagram illustrating a configuration example of the base station according to the second embodiment.
  • the control information processing unit 420 of the base station control station 400 in FIG. 19 has a configuration obtained by removing the allocation unit 123 from the control information processing unit 120 in FIG.
  • the base station 500 in FIG. 20 has a configuration in which the same function as the allocation unit 123 is added to the scheduling unit 551 of the mobile station control unit 550, and the adjacent cell information storage unit 5 53 is added to the scheduling unit 551.
  • the interference power calculation unit 122 of the base station control station 400 adds the downlink transmission power of one or more cells adjacent to the cell other than the base station that received the transmission of the interference power information for each slot.
  • the interference power value for each slot is calculated.
  • the scheduling unit 551 of the base station 500 performs slot allocation using the interference power value acquired from the base station control station 400 and the requested transmission power received from the mobile station 300.
  • the slot allocation procedure will be described later, but is generally the same as the procedure of the allocation unit 123 of the first embodiment.
  • the neighboring cell information storage unit 553 is a storage area that stores information related to neighboring cells. In this embodiment, the interference power value is stored as adjacent cell information.
  • the neighboring cell information storage unit 553 may be an area for temporarily storing neighboring cell information.
  • it may be a storage area that is secured only when slot allocation is performed. Therefore, it would be better if a mechanism for securing a storage area for storing neighboring cell information is provided. [0090] Since the block function related to the mobile station is the same as that of the first embodiment, the description thereof is omitted.
  • FIG. 21 is a sequence diagram showing an example of slot allocation in the second embodiment.
  • FIG. 14 which is a sequence diagram of the first embodiment, there is a difference that each base station 500 in each cell performs slot allocation and mobile station allocation for each slot of the radio communication frame.
  • base station control station 400 collects transmission power information from each base station 500 as in FIG. 14 (step S50).
  • a control signal periodically transmitted from the base station is transmitted to mobile station 300.
  • Each of (terminals A to G) performs reception (step S51).
  • Each mobile station 300 measures the received power level of the received signal (step S52), and further demodulates the received signal (step S53), thereby transmitting control information (transmission power information) transmitted from the base station 500. Can be obtained (step S54).
  • the control signal is transmitted at regular intervals such as 500 base stations, and the transmission power is set to the power and modulation scheme that can be received even when the mobile station 300 is located near the cell edge.
  • the control information transmitted in the control slot includes transmission power of the control slot that transmitted the control information and slot allocation information of each mobile station.
  • the propagation loss of the radio wave in the propagation path is calculated from the transmission power and reception power level obtained from the demodulated signal.
  • the mobile station derives the required transmission power and modulation scheme based on the above-described propagation loss (step S55), and notifies the base station 500 of the result via the uplink.
  • Base station 500 obtains the downlink required transmission power of each mobile station 300 required in the slot allocation method (step S57). During this time, base station 500 does not Send data! /, (Step S56).
  • Base station 500 receives the interference power value of each slot based on the downlink transmission power of neighboring base station 500 from base station control station 400 (step S58), and stores it in adjacent cell information storage section 553. .
  • the interference power value is calculated in the same way as in the first embodiment, and the interference level of the base station 500 of the adjacent cell that is the interference station is lower than the base station 500 of the nearest cell due to factors such as physical distance or topographical obstacles.
  • scheduling section 551 of base station 500 performs slot allocation in order of the highest required transmission power (step S59).
  • FIG. 22 is a flowchart showing an example of an operation of assigning slots used by the mobile station 300 in the base station 500. Scheduling section 551 assigns slots in the order of the largest required transmission power. Therefore, the mobile station that has requested the largest required transmission power is selected from the mobile stations 300 to which no slot is assigned (step S71). The allocation method allocates the selected requested transmission power to the unallocated slot having the smallest interference power value, which is the sum of the transmission powers of adjacent base stations 500 serving as interference waves (step S72).
  • the mobile station that has the highest required transmission power is assigned in order from the mobile station that requires the highest required transmission power, and the slot of the mobile station that has the next highest required transmission power is the slot other than the slot that is used by the mobile station that requires the highest required transmission power Assign it to the slot with the lowest total interference power value. Thereafter, the process is continued until there is no slot to which the above work is assigned (step S73).
  • the slot allocation result is reported to the mobile station in the cell by the control slot (step S74). Thereafter, the allocated data is transmitted in the downlink (step S75).
  • the base station sets downlink transmission power and assigns slots in the order of terminal F, terminal A, terminal B, terminal E, terminal C, terminal G, and terminal D.
  • the base station control station 400 obtains the downlink transmission power information of the base station power of cell 2 and cell 3 that are adjacent base stations. Collected and calculated the sum of each slot as an interference power value (implemented by interference power calculation unit 122) o Notifies the calculated interference power value to base station 500 to which allocation is performed.
  • Allocation at base station 500 is such that V ⁇ mobile station 300 has the largest required transmission power in the slot with the smallest interference power value in each slot.
  • the request transmission below the threshold is requested.
  • the transmission power may be different from that shown in FIG. Here, we have only shown cases where similar results are obtained.
  • the required transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells.
  • the required transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells.
  • base station control station 400 has explained the case of notifying base station 500 of the interference power value calculated from the transmission power information, but notifying base station 200 of the transmission power information itself. It may be the case. In this case, although the amount of information notified from the base station control station 400 to the base station 200 increases, the processing amount of the base station control station 400 itself decreases. Also, the neighboring cell information storage unit 553 stores transmission power information.
  • the base station control station 400 of the present embodiment may be configured to include the allocation unit 123.
  • the interference power value transmission request from the base station control station 100 shown in FIG. 3 from the base station 500 may be received and the interference power value notified.
  • the base station control station 100 shown in FIG. 3 also has a function of accepting an interference power value transmission request, the base station 200 shown in FIG. 4 and the base station 500 shown in FIG. It will be good.
  • the frame configuration of the present embodiment is a communication method having both features of the TDMA method and the FDMA method, and is a communication method generally used in the multicarrier communication method.
  • the description of the TDMA method and the FDMA method is omitted because it has been described in the first embodiment.
  • FIG. 23 is a diagram illustrating an example of a multi-carrier Z (TDMA, FDMA) two-dimensional frame configuration that is a target of the third embodiment.
  • the vertical axis is frequency and the horizontal axis is time.
  • one of the squares is the minimum unit used for data transmission, and in the present embodiment this is called a slot.
  • the shaded square is the control slot (TO). In the case of this figure, this means that there are 9 slots in the time direction and 12 slots in the frequency direction in one frame, and there are a total of 108 slots (of which 12 slots are control slots). Means.
  • Base station power When performing wireless data communication with a mobile station, the base station allocates each small square (slot) in Fig. 23 shown in the description of the frame configuration above to a different mobile station and transmits data. It is also possible to perform wireless communication by assigning all slots to one mobile station.
  • a method for performing transmission power allocation in the base station control station shown in the first embodiment using the frame configuration described above, or a method for performing slot allocation in the base station shown in the second embodiment Wireless data communication is performed by using.
  • the required transmission power derived from the propagation path condition power of each mobile station is reduced.
  • the required transmission power derived from the propagation path condition power of each mobile station is reduced.
  • any one of the base stations 200 has a slot allocation function.
  • the base stations 200a, 200c, and 200d exchange with the base station 200b the parts that were exchanged with the base station control stations 100 and 400 in the first embodiment and the second embodiment. That is, the base stations 200a, 200c, and 200d communicate with the base station 200b in step S19, step S21, and step S23 in FIG. 14, or step S58 and step S60 in FIG.
  • the base station 200b having the slot assignment function has at least the following components.
  • a transmission power storage unit serving as a storage area for storing transmission power information is added to the configuration of base station 200 in FIG.
  • the other components are the same.
  • the function of slot allocation from another base station 200 needs to be added to the function of the power scheduling unit 251. That is, the scheduling unit 251 needs to have a function of performing slot allocation requested from another base station 200.
  • the scheduling unit 251 uses the transmission power information and one or more adjacent to the own cell that is the control target. By adding the downlink transmission power of each cell for each slot, the interference power value for each slot is calculated, and the received requested transmission power is allocated to a slot where the interference power value is smaller than a predetermined value. .
  • the slot allocation of other cells is performed as follows.
  • the scheduling unit 251 calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to other cells for each slot, and calculates the interference power value.
  • Allocation information for assigning the requested transmission power acquired to the slot is generated when the power value is smaller than the predetermined value.
  • the created allocation information is notified to other base stations by the base station notification unit 210.
  • the base station 200b has a slot assignment function
  • a plurality of base stations may have a slot assignment function.
  • all base stations may have a slot allocation function.
  • a specific base station has a function of collecting transmission power information, a function of calculating an interference power value, and a function of assigning a slot using the interference power value.
  • the structure to do can be taken.
  • each base station has a function of allocating slots using the interference power value.
  • the base station 500 (FIG. 20) described in the second embodiment is used. become. In this way, it is possible to reduce the interference of neighboring cells.
  • the plurality of mobile stations report the setting value of the downlink transmission power used for transmission to the base station control station or the base station, and the base station control station or the base station Then, based on the reported downlink transmission power setting value, the base station downlink transmission power setting value is determined, and allocation is performed so that the amount of interference among a plurality of base stations is minimized.
  • the base station control station or the base station to allocate the slot transmission power so that the interference power value of the mobile station of its own cell becomes smaller in consideration of the transmission power of the adjacent cell.
  • each mobile station can perform good reception in a state where the amount of interference from adjacent base stations is minimized while repeating one cell. In particular, it is possible to reduce interference between cells in a wireless communication system using the same frequency between a plurality of adjacent cells.
  • HSDPA High
  • the -Speed Downlink Packet Access basically aims to achieve the maximum transmission rate that adapts to the downlink propagation state by keeping the transmission power constant and dynamically selecting the modulation method and error correction coding rate.
  • the power of the interference power can basically be treated as constant, while it is constant even when the distance between the base station and the mobile station is short. Therefore, it is transmitted to the mobile station in a sufficiently good reception environment using the excess transmission power.
  • the effect of controlling the downlink transmission power to an appropriate value for the mobile station is not limited to the above-described reduction of the excessive transmission power of the base station, but to adjacent cells.
  • the effect of reducing the influence of is also produced. That is, by reducing the transmission power, it becomes difficult for a signal to reach an adjacent cell from its own cell, and as a result, the power of an interference signal for the adjacent cell can be reduced.
  • a one-cell repetition method in which the same frequency is used in adjacent cells.
  • a base station that manages the cell is arranged in one cell, a plurality of base stations are centrally controlled by the control station, at least a slot is allocated to the mobile station, and Base station power Direction to mobile station Effectively applied to a radio communication system in which transmission power control is performed on the downlink, a control station or a base station having at least a part of functions of this control station It has been explained that at least the components (means) for implementing the above functions are provided.
  • Function to collect downlink transmission power information allocated to each slot from each base station that manages each of a plurality of adjacent cells (information collecting means), (2) In the collected transmission power information Based!
  • a function for generating information (interference information, interference power value) indicating the interference status for each slot (interference information generating means), and (3) the interference status for each slot when downlink communication is performed.
  • a function (allocation means) that dynamically (adaptively) allocates a slot with a low interference level to a destination mobile station based on the information shown. That is, there is a difference between the control station or base station of the radio communication system! /, And the downlink transmission power information notified from the mobile station is transmitted via the base station of each cell.
  • the description has been made on the assumption that slot allocation is performed independently for each cell. This is because the base station control station and the allocation performed by the base station are performed by referring to the neighboring base station information, and it is preferable that each base station under the control of the base station performs the reassignment work at a different time. based on.
  • the interference situation changes simultaneously in the post-allocation frame, which may affect the radio communication quality. For this reason, it is desirable to prevent a phenomenon in which slot allocation is performed simultaneously for a plurality of cells.
  • the mobile station can increase the downlink transmission power by intentionally increasing the required transmission power for transmission.
  • the required transmission power can be increased especially in the case of emergency contact or when it is desired to construct an emergency contact network in the event of a disaster.
  • mobile stations with high publicity such as those used in disasters, can be provided with an emergency mode, etc., and a function to increase the required transmission power by changing the mode.
  • FIG. 1 is a diagram showing an example of a frame configuration.
  • Fig. 1 (a) shows an example of a typical TDMA frame structure.
  • Figure 1 (b) shows an example of a general FDMA frame structure.
  • FIG. 2 is a diagram illustrating a configuration example of a wireless communication system according to the first embodiment.
  • FIG. 3 is a block diagram illustrating a configuration example of a base station control station according to the first embodiment.
  • FIG. 4 is a block diagram illustrating a configuration example of a base station according to the first embodiment.
  • FIG. 5 is a block diagram illustrating a configuration example of a mobile station according to the first embodiment.
  • FIG. 6 is a diagram showing a typical example of a cell and a terminal arrangement existing in the cell.
  • FIG. 7 is a diagram showing the relative relationship between the required transmission power levels for terminals A to F in cell 1.
  • FIG. 8 is a diagram showing a frame configuration example used in the first embodiment.
  • FIG. 9 is a diagram showing the relationship between cells and terminal arrangements.
  • FIG. 10 is a diagram showing a relative relationship between the magnitudes of requested transmission powers for terminals H to N in cell 2.
  • FIG. 11 is a diagram showing a relative relationship between the magnitudes of requested transmission powers for terminals 0 to U in cell 3.
  • FIG. 12 is a diagram showing the slot allocation status of each terminal H to N in cell 2.
  • FIG. 13 is a diagram showing the slot allocation status of terminals 0 to U in cell 3;
  • FIG. 14 is a sequence diagram showing an example of slot allocation in the first embodiment.
  • FIG. 15 is a diagram showing the sum of transmission power for each slot of a plurality of cells.
  • FIG. 17 is a flowchart showing an example of a procedure for a base station to assign a mobile station to each slot.
  • FIG. 18 is a diagram illustrating an example of a slot allocation result according to the first embodiment.
  • FIG. 19 is a block diagram illustrating a configuration example of a base station control station according to the second embodiment.
  • ⁇ 20 is a block diagram showing an example of the configuration of a base station according to the second embodiment
  • FIG. 21 is a sequence diagram showing an example of slot allocation in the second embodiment.
  • FIG. 22 is a flowchart showing an example of an operation of assigning slots used by mobile stations in a base station.
  • FIG. 23 is a diagram showing an example of a multi-carrier Z (TDMA, FDMA) two-dimensional frame configuration that is a target of the third embodiment.
  • FIG. 24 is a diagram showing a frequency allocation example of a radio communication scheme in which radio communication is performed using different frequency bands in adjacent cells.

Abstract

[PROBLEMS] In a wireless communication system having a plurality of adjacent cells, there is provided a control station (base station control station) that allocates slots in accordance with the downlink transmission powers of the adjacent cells. [MEANS FOR SOLVING PROBLEMS] A base station control station (100), which manages a plurality of base stations, comprises a control station acquisition part (110) that collects, from each base station of a respective one of the cells, the downlink transmission power allocated to each slot, and acquires, from the base station of a particular cell, a required transmission power required in a downlink communication with a mobile station; an interference power calculating part (122) that adding together the downlink transmission powers of one or more cells adjacent to the particular cell for each of the slots, thereby calculating an interference power value for each of the slots; an allocating part (123) that allocates the required transmission power to a slot having a small interference power value; and a control station notification part (130) that notifies, to the base station of the particular cell, the allocation information related to the allocation of the required transmission power to the slot.

Description

明 細 書  Specification
制御局、基地局、スロット割当方法、および無線通信システム  Control station, base station, slot allocation method, and radio communication system
技術分野  Technical field
[0001] 本発明は、複数のセルが隣接する無線通信システムにおけるスロット割当の制御に 関する。  The present invention relates to slot assignment control in a wireless communication system in which a plurality of cells are adjacent.
背景技術  Background art
[0002] 従来、移動体通信システムでは、セル内にある 1つの基地局に対し複数の移動局 を接続して同時に無線通信を行なう多元接続方式で通信が行なわれて 、る。複数の セルが面的に展開されるマルチセル環境での移動体通信システムでは、隣接セルに ある基地局からの電波が干渉波となる。このため、干渉波を回避するための通信方 式が採用されている。例えば隣接する基地局がそれぞれのセルにおいて別々の周 波数帯域を使用する通信方式や、 CDMA (Code Division Multiple Access) 通信方式のように基地局毎に固有の拡散コードを使用することによって干渉を回避 する無線通信方式である。  Conventionally, in a mobile communication system, communication is performed by a multiple access method in which a plurality of mobile stations are connected to one base station in a cell and wireless communication is simultaneously performed. In a mobile communication system in a multi-cell environment where a plurality of cells are spread across, a radio wave from a base station in an adjacent cell becomes an interference wave. For this reason, a communication method for avoiding interference waves is adopted. For example, adjacent base stations avoid interference by using a unique spreading code for each base station, such as a communication system that uses different frequency bands in each cell or a CDMA (Code Division Multiple Access) communication system. Wireless communication system.
[0003] 図 24は、隣接するセルにおいて異なる周波数帯域を利用して無線通信を行なう無 線通信方式の周波数割当例を示す図である。図 24では、無線通信方式の正六角形 セルにおける周波数繰り返し数 3の典型的な周波数割当例を示している。同図では 全周波数帯域幅を一定帯域幅で等分し、同一の分割された周波数帯域を隣り合うセ ルで使用しないように周波数帯域の割当が行なわれている。これによつて、隣接する セルでは同一周波数を使用しな!、ため、セルエッジ付近で干渉波による無線通信品 質の劣化を防ぐことができる。  [0003] FIG. 24 is a diagram showing an example of frequency allocation in a radio communication scheme in which radio communication is performed using different frequency bands in adjacent cells. FIG. 24 shows a typical frequency allocation example with a frequency repetition number of 3 in a regular hexagonal cell of a wireless communication system. In this figure, all frequency bandwidths are equally divided by a fixed bandwidth, and frequency bands are assigned so that the same divided frequency band is not used in adjacent cells. As a result, the same frequency is not used in adjacent cells! Therefore, it is possible to prevent deterioration of radio communication quality due to interference waves near the cell edge.
[0004] また、 CDMA通信方式はセル毎に異なる拡散符号を信号に乗算するため、干渉 に対して耐性のある通信方式である。その一方で、干渉電力が増加すると通信品質 が劣化するため、移動局の受信信号電力と受信干渉電力との相対電力比を上げる 必要がある。隣接基地局力もの送信電力の増加は自セル内にある移動局に対して は干渉電力の原因となるため、特に隣接基地局力 の干渉電力が大きいセルエッジ 付近にある移動局には伝送レートを下げ、拡散による利得を上げることにより、干渉 に対する耐性を上げて通信を行わなくてはならな力つた。 [0004] In addition, the CDMA communication system is a communication system that is resistant to interference because a signal is multiplied by a spreading code that is different for each cell. On the other hand, since the communication quality deteriorates when the interference power increases, it is necessary to increase the relative power ratio between the received signal power of the mobile station and the received interference power. Since the increase in transmission power of adjacent base station power causes interference power for mobile stations in its own cell, the transmission rate is set especially for mobile stations near the cell edge where the interference power of adjacent base station power is large. Interference by lowering and increasing gain by spreading I had to increase the resistance to communication and communicate.
[0005] さらに、近年高速移動体通信の要求が高まり、周波数利用効率が高ぐ高速，大容 量の通信が望まれるようになるにつれて通信システム内の全ての基地局が同一の周 波数帯域を利用して移動体無線通信を行なう 1セル繰り返し通信方式の研究が盛ん に行なわれてくるようになった。  [0005] Furthermore, as the demand for high-speed mobile communication has increased in recent years and high-speed, large-capacity communication with high frequency utilization efficiency has become desirable, all base stations in the communication system have the same frequency band. Research on a one-cell repetitive communication method that uses mobile radio communication by using it has been actively conducted.
非特許文献 1 :阪田史郎， "ワイヤレス'ュビキタス 高速無線 LANZUWBZ3. 5G 携帯電話，，秀和システム， P. 195-210, 2004  Non-Patent Document 1: Shiro Sakata, “Wireless Ubiquitous High-Speed Wireless LANZUWBZ3.5G Mobile Phone, Hidekazu System, P. 195-210, 2004
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0006] し力しながら、前述した従来の無線通信システムにおいて、以下に述べるような問 題が考えられる。 However, in the conventional wireless communication system described above, the following problems can be considered.
[0007] まず、周波数分割によるセル繰り返しによるシステムでは隣接セルと異なった周波 数を自セルで使用するためセル間干渉は起こらな 、が、周波数帯域を分割して使用 するため周波数利用効率が悪く十分に高速な通信が行えな力つた。また、前記 CD MA通信方式においてはセルエッジ付近での干渉による電波環境の劣化が符号利 得特性を上回ると、十分な伝送速度が得られなかった。  [0007] First, in a system using cell repetition by frequency division, inter-cell interference does not occur because a frequency different from that of an adjacent cell is used in the own cell, but frequency utilization efficiency is poor because a frequency band is divided and used. It was powerful enough to perform high-speed communication. In the CD MA communication method, if the deterioration of the radio wave environment due to interference near the cell edge exceeds the code gain characteristic, a sufficient transmission rate cannot be obtained.
[0008] 本発明は、このような事情に鑑みてなされたものであり、複数のセルが隣接する無 線通信システムにお 、て、隣接セルのダウンリンク送信電力に応じてスロットを割り当 てる制御局、基地局、および、スロット割当方法を提供することを目的とする。  [0008] The present invention has been made in view of such circumstances, and in a wireless communication system in which a plurality of cells are adjacent, slots are allocated according to the downlink transmission power of the adjacent cells. It is an object to provide a control station, a base station, and a slot allocation method.
課題を解決するための手段  Means for solving the problem
[0009] (1)本発明に係る制御局 (基地局制御局）の一態様は、複数の隣接するセル間で 同一周波数を用いる無線通信システムで、複数のスロットから構成されるフレームを 用いてセル内の移動局と無線通信する複数の基地局を管理する制御局であって、 各スロットに割り当てられたダウンリンク送信電力を複数のセルそれぞれの基地局か ら収集すると共に、移動局とのダウンリンク通信に要求される要求送信電力を特定の セルの基地局から取得する制御局取得部と、前記特定のセルに隣接する一つ以上 のセルのダウンリンク送信電力をスロット毎に加算することにより、スロット毎の干渉電 力値を算出する干渉電力算出部と、前記干渉電力値が所定の値と比較して小さいス ロットへ前記要求送信電力を割り当てる割当部と、前記要求送信電力をスロットへ割 り当てた割当情報を、前記特定のセルの基地局へ通知する制御局通知部と、を備え ることを特徴とする。 [0009] (1) One aspect of the control station (base station control station) according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots. A control station that manages a plurality of base stations that communicate wirelessly with mobile stations in a cell, and collects downlink transmission power allocated to each slot from the base stations of each of the plurality of cells and A control station acquisition unit that acquires the required transmission power required for downlink communication from a base station of a specific cell, and the downlink transmission power of one or more cells adjacent to the specific cell are added for each slot The interference power calculation unit for calculating the interference power value for each slot, and the interference power value is smaller than the predetermined value. An allocation unit that allocates the requested transmission power to a lot; and a control station notification unit that notifies allocation information that allocates the requested transmission power to a slot to a base station of the specific cell. To do.
[0010] このように、この制御局は、隣接セルのダウンリンク送信電力を加算して干渉電力値 として算出し、干渉電力値が小さいスロットへダウンリンク通信に要求される要求送信 電力を割り当てるので、隣接セルのダウンリンク送信電力に応じて適応的にスロットを 割り当てて、セル間干渉を削減することが可能となる。なお、非特許文献 1に記載の 技術は 3GPP (3rd Generation Partnership Project)で仕様が承認された HS DPA(High Speed Downlink Packet Access)に書かれたものである。特に、 本発明に関連する技術としては「適応スケジューリング」と呼ばれる技術であり、 HSD PAでの特徴的な技術のひとつである。 HSDPAでは本発明の実施例と同様に TD MA通信方式を使用しており、フレーム内の各スロットを移動局からの伝搬路状態を 示す制御情報である CQI (Channel Quality Indication)に基づいて割当を行な う。一方、本発明との相違点としては、 HSDPAでは各スロットの送信電力は一定で あり隣接セルにおける干渉電力の時間的変化はないが、本発明では各スロットの送 信電力を積極的に制御し隣接セルに与える干渉を低減している。また、移動局での 動作の違いは HSDPAではスロット毎に CQIを返す必要がある力 本発明では伝搬 損から算出される情報をフレーム毎 (スケジューリングが行われる毎）に返せばよいこ ととなる。  [0010] In this way, this control station adds the downlink transmission power of adjacent cells to calculate an interference power value, and allocates the required transmission power required for downlink communication to a slot with a small interference power value. Thus, it is possible to adaptively allocate slots according to the downlink transmission power of adjacent cells to reduce inter-cell interference. The technology described in Non-Patent Document 1 is written in HS DPA (High Speed Downlink Packet Access) whose specifications have been approved by 3GPP (3rd Generation Partnership Project). In particular, a technique related to the present invention is a technique called “adaptive scheduling”, which is one of the characteristic techniques in HSD PA. HSDPA uses the TDMA communication method as in the embodiment of the present invention, and assigns each slot in a frame based on CQI (Channel Quality Indication), which is control information indicating the channel state from the mobile station. Do it. On the other hand, the difference from the present invention is that, in HSDPA, the transmission power of each slot is constant and there is no temporal change in the interference power in adjacent cells, but the present invention actively controls the transmission power of each slot. Interference applied to adjacent cells is reduced. Also, the difference in operation at the mobile station is that HSDPA needs to return CQI for each slot. In the present invention, information calculated from propagation loss should be returned for each frame (every time scheduling is performed).
[0011] (2)また、本発明に係る制御局の一態様において、前記制御局取得部は、複数の 要求送信電力を取得し、前記割当部は、複数のスロットのうち干渉電力値が小さいス ロットを順番に選択し、選択したスロットへ複数の要求送信電力を大き!ヽ順に割り当 てることを特徴としている。  [0011] (2) Further, in one aspect of the control station according to the present invention, the control station acquisition unit acquires a plurality of requested transmission powers, and the allocation unit has a small interference power value among the plurality of slots. It is characterized by selecting slots in order and assigning multiple required transmission powers to the selected slots in descending order.
[0012] このように、要求送信電力が大きい順に、干渉電力値が小さいスロットを順番に割り 当てるので、隣接セルの干渉電力の影響を抑制することができる。  [0012] As described above, since the slots having the smaller interference power values are assigned in order from the largest required transmission power, the influence of the interference power of the adjacent cell can be suppressed.
[0013] (3)さらに、本発明に係る制御局の別の一態様は、複数の隣接するセル間で同一 周波数を用いる無線通信システムで、複数のスロットから構成されるフレームを用い てセル内の移動局と無線通信する複数の基地局を管理する制御局であって、複数 の基地局において各スロットに割り当てられたダウンリンク送信電力をセルと対応づ けて記憶する送信電力記憶部と、特定のセルに隣接する一つ以上のセルのダウンリ ンク送信電力をスロット毎に加算することにより、スロット毎の干渉電力値を算出する 干渉電力算出部と、基地局から、前記干渉電力値の送付要求を取得する制御局取 得部と、前記干渉電力算出部が前記送付要求した基地局のセルを前記特定のセル として選択して算出した干渉電力値を前記基地局へ通知する制御局通知部と、を備 えることを特徴とする。 [0013] (3) Furthermore, another aspect of the control station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots to make an intra-cell Control station that manages a plurality of base stations that communicate wirelessly with other mobile stations, The transmission power storage unit that stores the downlink transmission power assigned to each slot in each base station in association with the cell, and the downlink transmission power of one or more cells adjacent to a specific cell are added for each slot. An interference power calculation unit that calculates an interference power value for each slot, a control station acquisition unit that acquires a transmission request for the interference power value from a base station, and the interference power calculation unit that has made the transmission request. A control station notifying unit for notifying the base station of an interference power value calculated by selecting a cell of the base station as the specific cell.
[0014] このように、この制御局は、隣接セルのダウンリンク送信電力を干渉電力値として算 出して基地局へ通知することにより、スロット割当を実施する基地局へ干渉電力値の 情報を提供することができる。これにより、基地局が隣接セルのダウンリンク送信電力 に応じて適応的にスロットを割り当てることを可能とし、セル間干渉を削減することが 可能となる。  [0014] Thus, the control station calculates the downlink transmission power of an adjacent cell as an interference power value and notifies the base station, thereby providing information on the interference power value to the base station that performs slot allocation. can do. As a result, the base station can adaptively allocate slots according to the downlink transmission power of neighboring cells, and can reduce inter-cell interference.
[0015] (4)本発明に係る基地局の一態様は、複数の隣接するセル間で同一周波数を用 V、る無線通信システムで、制御対象であるセル内の移動局と無線通信する基地局で あって、前記移動局がダウンリンク送信電力として要求する要求送信電力を受信する 受信部と、請求項 1記載の制御局へ、前記要求送信電力を通知する基地局通知部と 、前記制御局力 要求送信電力をスロットへ割り当てた割当情報を取得する基地局 取得部と、前記割当情報を用いて、前記要求送信電力を要求した移動局とスロットと を対応づけるスケジューリング部と、前記要求送信電力を要求した移動局へ、前記要 求送信電力を割り当てたスロットを通知する送信部と、を備えることを特徴とする。  [0015] (4) One aspect of the base station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells in a base station that performs wireless communication with a mobile station in a cell to be controlled. A receiving unit that receives a request transmission power requested by the mobile station as a downlink transmission power, a base station notification unit that notifies the control station according to claim 1, and the control station A base station acquisition unit that acquires allocation information in which requested transmission power is allocated to a slot; a scheduling unit that associates a mobile station that has requested the requested transmission power with a slot using the allocation information; and the request transmission And a transmitter that notifies the mobile station that has requested power of the slot to which the requested transmission power is allocated.
[0016] このように、この基地局は、隣接セルのダウンリンク送信電力を干渉電力値として算 出し、取得した割当情報を用いてダウンリンク通信に要求される要求送信電力を干渉 電力値が小さいスロットへスケジューリングをすることができる。これにより、隣接セル のダウンリンク送信電力に応じて適応的にスロットを割り当てて、セル間干渉を削減 することが可能となる。  [0016] Thus, this base station calculates the downlink transmission power of an adjacent cell as an interference power value, and uses the obtained allocation information to obtain the required transmission power required for downlink communication with a small interference power value. You can schedule to slots. As a result, it is possible to adaptively allocate slots according to the downlink transmission power of adjacent cells to reduce inter-cell interference.
[0017] (5)また、本発明に係る基地局の一態様において、前記受信部は、複数の要求送 信電力を受信し、前記スケジューリング部は、受信した複数の要求送信電力のうち、 所定の閾値より大きい要求送信電力を選択し、前記基地局通知部は、選択した要求 送信電力を通知することを特徴とする。 [0017] (5) Also, in one aspect of the base station according to the present invention, the receiving unit receives a plurality of request transmission powers, and the scheduling unit is a predetermined one of the plurality of received request transmission powers. Request transmission power larger than the threshold of the base station, the base station notification unit, the selected request The transmission power is notified.
[0018] このように、複数の要求送信電力の一部分を制御局に通知することにより、制御局 と基地局間の通信量、情報処理量を調整することができる。  [0018] As described above, by notifying the control station of a part of the plurality of requested transmission powers, it is possible to adjust the communication amount and the information processing amount between the control station and the base station.
[0019] (6)本発明に係る基地局の別の一態様は、複数の隣接するセル間で同一周波数 を用いる無線通信システムで、複数のスロットから構成されるフレームを用いて制御 対象であるセル内の移動局と無線通信する基地局であって、制御対象であるセルに 隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に加算することによりス ロット毎に算出された干渉電力値を制御局から取得する基地局取得部と、前記移動 局がダウンリンク送信電力として要求する要求送信電力を受信する受信部と、前記取 得した干渉電力値が小さ 、スロットへ受信した要求送信電力を割り当てるスケジユー リング部と、前記要求送信電力を要求した移動局へ、前記要求送信電力を割り当て たスロットを通知する送信部と、を備えることを特徴とする。  [0019] (6) Another aspect of the base station according to the present invention is a radio communication system that uses the same frequency between a plurality of adjacent cells, and is a control target using a frame configured of a plurality of slots. Interference power calculated for each slot by adding the downlink transmission power of one or more cells adjacent to the cell to be controlled for each slot. A base station acquisition unit that acquires a value from a control station, a reception unit that receives a request transmission power requested by the mobile station as a downlink transmission power, and a request transmission that is received in a slot when the acquired interference power value is small. A scheduling unit for allocating power, and a transmitter for notifying a mobile station that has requested the requested transmission power of a slot to which the requested transmission power is allocated.
[0020] このように、この基地局は、干渉電力値を取得し、ダウンリンク通信に要求される要 求送信電力を干渉電力値が小さいスロットへ割り当てることができる。これにより、隣 接セルのダウンリンク送信電力に応じて適応的にスロットを割り当てて、セル間干渉を 削減することが可能となる。また、基地局内で干渉電力値を用いてスロット割当をする ことにより、制御局と基地局との間でやり取りする情報量が、制御局でスロット割当を する場合に比べ削減することが可能となる。  [0020] In this way, the base station can acquire the interference power value, and can allocate the required transmission power required for downlink communication to a slot with a small interference power value. This makes it possible to adaptively allocate slots according to the downlink transmission power of neighboring cells and reduce inter-cell interference. Also, by allocating slots using the interference power value in the base station, it is possible to reduce the amount of information exchanged between the control station and the base station compared to the slot allocation in the control station. .
[0021] (7)また、本発明に係る基地局の更に別の一態様は、複数の隣接するセル間で同 一周波数を用いる無線通信システムで、複数のスロットから構成されるフレームを用 V、て制御対象であるセル内の移動局と無線通信すると共に、他の基地局を管理する 基地局であって、他の基地局のセルについて各スロットに割り当てられたダウンリンク 送信電力を収集する基地局取得部と、前記移動局がダウンリンク送信電力として要 求する要求送信電力を受信する受信部と、前記制御対象であるセルに隣接する一 つ以上のセルのダウンリンク送信電力をスロット毎に加算することにより、スロット毎の 干渉電力値を算出する干渉電力算出部と、前記干渉電力値が小さいスロットへ受信 した要求送信電力を割り当てるスケジューリング部と、前記要求送信電力を要求した 移動局へ、前記要求送信電力を割り当てたスロットを通知する送信部と、を備えること を特徴とする。 [0021] (7) Further, another aspect of the base station according to the present invention is a wireless communication system using the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots. A base station that performs radio communication with a mobile station in a cell to be controlled and manages other base stations, and collects downlink transmission power allocated to each slot for the cells of other base stations The base station acquisition unit, the receiving unit that receives the requested transmission power required by the mobile station as the downlink transmission power, and the downlink transmission power of one or more cells adjacent to the cell to be controlled for each slot An interference power calculation unit that calculates an interference power value for each slot, a scheduling unit that allocates the requested transmission power received to a slot with a small interference power value, and the request A transmission unit that notifies a mobile station that has requested transmission power of a slot to which the requested transmission power is allocated. It is characterized by.
[0022] このように、この基地局は、各セルのダウンリンク送信電力を収集し、干渉電力値を 算出する機能を有し、干渉電力値の小さいスロットへ要求送信電力を割り当てること ができる。複数の基地局のうち、少なくとも一つの基地局が干渉電力値を用いたスロ ット割当の手段を有することにより、少なくとも一つの基地局が隣接セルのダウンリン ク送信電力に応じて適応的にスロット割り当てることができる。これにより、干渉電力値 に応じて、制御対象である自己のセルのスロットを割り当てることが可能となる。  [0022] Thus, this base station has a function of collecting the downlink transmission power of each cell and calculating the interference power value, and can allocate the requested transmission power to a slot with a small interference power value. Among the plurality of base stations, at least one base station has a slot allocating unit using the interference power value, so that at least one base station can adaptively slot according to the downlink transmission power of the adjacent cell. Can be assigned. As a result, it is possible to assign the slot of its own cell to be controlled according to the interference power value.
[0023] (8)本発明に係る基地局の一態様において、前記基地局取得部は、他のセルの移 動局が要求する要求送信電力を他の基地局から取得し、前記干渉電力算出部は、 前記他のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に加算 することにより、スロット毎の干渉電力値を算出し、前記スケジューリング部は、前記干 渉電力値が小さいスロットへ取得した要求送信電力を割り当てる割当情報を作成し、 前記基地局通知部は、前記他の基地局へ作成した割当情報を通知することを特徴と する。  (8) In one aspect of the base station according to the present invention, the base station acquisition unit acquires the requested transmission power requested by the mobile station of another cell from the other base station, and calculates the interference power. The unit calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the other cell for each slot, and the scheduling unit determines that the interference power value is An allocation information for allocating the requested transmission power acquired to a small slot is created, and the base station notification unit notifies the created allocation information to the other base station.
[0024] このように、この基地局は、他の基地局力 要求送信電力を取得した場合、他の基 地局のセルへの干渉電力値を算出し、干渉電力値の小さいスロットへ要求送信電力 を割り当てることができる。これにより、複数の基地局のうち、少なくとも一つの基地局 が干渉電力値を用いたスロット割当の手段を有することにより、少なくとも一つの基地 局が隣接セルのダウンリンク送信電力に応じて適応的にスロット割り当てることができ る。  [0024] Thus, when this base station acquires other base station power request transmission power, it calculates the interference power value to the cell of the other base station, and requests transmission to a slot with a small interference power value. Power can be allocated. As a result, at least one base station among the plurality of base stations has a slot allocation means using the interference power value, so that at least one base station adaptively responds to the downlink transmission power of the adjacent cell. Slots can be assigned.
[0025] (9)本発明に係る基地局の一態様において、前記スケジューリング部は、複数のス ロットのうち干渉電力値が小さ 、スロットを順番に選択し、選択したスロットへ複数の 要求送信電力を大き 、順に割り当てることを特徴とする。  [0025] (9) In one aspect of the base station according to the present invention, the scheduling unit selects a slot in order from among a plurality of slots, the interference power value being small, and a plurality of requested transmission powers to the selected slot. Are assigned in order of size.
[0026] このように、要求送信電力が大きい順に、干渉電力値が小さいスロットを順番に割り 当てるので、隣接セルの干渉電力の影響を抑制することができる。  [0026] Thus, since the slots with the smaller interference power values are assigned in order from the largest required transmission power, the influence of the interference power of adjacent cells can be suppressed.
[0027] (10)本発明に係る制御局のスロット割当方法の一態様は、複数の隣接するセル間 で同一周波数を用いる無線通信システムで、複数のスロットから構成されるフレーム を用いてセル内の移動局と無線通信する複数の基地局を管理する制御局のスロット 割当方法であって、複数のセルそれぞれにつ 、て各スロットに割り当てられたダウン リンク送信電力を複数の基地局から収集するステップと、移動局とのダウンリンク通信 に要求される要求送信電力を特定のセルの基地局力 受け付けるステップと、前記 特定のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に加算す ることにより、スロット毎の干渉電力値を算出するステップと、前記干渉電力値が小さ V、スロットへ前記要求送信電力を割り当てるステップと、前記要求送信電力をスロット へ割り当てた割当情報を、前記特定のセルの基地局へ通知するステップと、を少なく とも含むことを特徴とする。 [0027] (10) One aspect of a slot allocation method for a control station according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and uses a frame composed of a plurality of slots in the cell Control station slot that manages multiple base stations that communicate wirelessly with other mobile stations A method for allocating downlink transmission power allocated to each slot for each of a plurality of cells from a plurality of base stations, and request transmission power required for downlink communication with a mobile station. Receiving a base station power of a specific cell; calculating an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot; Assigning the requested transmission power to a slot having a small interference power value V and notifying the allocation information allocating the requested transmission power to the slot to the base station of the specific cell. It is characterized by.
[0028] このように、このスロット割当方法は、隣接セルのダウンリンク送信電力を干渉電力 値として算出し、ダウンリンク通信に要求される要求送信電力を干渉電力値が小さい スロットへ割り当てるので、隣接セルのダウンリンク送信電力に応じて適応的にスロッ トを割り当てて、セル間干渉を削減することが可能となる。  [0028] Thus, in this slot allocation method, the downlink transmission power of an adjacent cell is calculated as an interference power value, and the requested transmission power required for downlink communication is allocated to a slot with a small interference power value. Inter-cell interference can be reduced by adaptively assigning slots according to the downlink transmission power of the cell.
[0029] (11)本発明に係る無線通信システムのスロット割当方法の一態様は、複数の隣接 するセル間で同一周波数を用いる無線通信システムで、移動局が存在する複数のセ ルが隣接し、複数のスロットから構成されるフレームを用いる無線通信システムのスロ ット割当方法であって、複数のセルそれぞれの基地局力 各スロットに割り当てられ たダウンリンク送信電力を収集するステップと、前記収集したダウンリンク送信電力の うち、特定のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に 加算することにより、スロット毎の干渉電力値を算出するステップと、ダウンリンク送信 電力として要求される要求送信電力を前記特定のセルの基地局から取得するステツ プと、前記干渉電力値が小さ!、スロットへ前記要求送信電力を割り当てるステップと、 を少なくとも含むことを特徴とする。  [0029] (11) One aspect of a slot allocation method for a wireless communication system according to the present invention is a wireless communication system that uses the same frequency between a plurality of adjacent cells, and a plurality of cells in which a mobile station exists are adjacent to each other. A slot allocation method of a radio communication system using a frame composed of a plurality of slots, the base station power of each of a plurality of cells collecting the downlink transmission power allocated to each slot, and the collection Of the downlink transmission power, the step of calculating the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to a specific cell for each slot, and the downlink transmission power as A step of obtaining the required transmission power required from the base station of the specific cell, and the interference power value is small! Characterized in that it comprises the steps of assigning a force, at least.
[0030] このように、この無線通信システムの制御局あるいは基地局の 、ずれかにお!/、て、 ダウンリンク通信に要求される要求送信電力を隣接セルのダウンリンク送信電力が小 さ 、スロットへ割り当てるので、隣接セルのダウンリンク送信電力に応じて適応的にス ロットを割り当てて、セル間干渉を削減することが可能となる。また、隣接セルのダウン リンク送信電力を用いて干渉電力値を算出するので、隣接セルの干渉電力値に応じ てスロットを割り当てることが可能となり、セル間の干渉を削減することができる。 [0031] (12)本発明に係る制御局の一態様において、前記干渉電力算出部は、減衰量に 応じた係数を前記ダウンリンク送信電力へ乗算し、前記係数を乗算したダウンリンク 送信電力をスロット毎に加算することを特徴とする。 [0030] In this way, the required transmission power required for the downlink communication is less than that of the control station or base station of this wireless communication system, and the downlink transmission power of the adjacent cell is small. Since it is assigned to the slot, it becomes possible to adaptively assign the slot according to the downlink transmission power of the adjacent cell and reduce inter-cell interference. In addition, since the interference power value is calculated using the downlink transmission power of the adjacent cell, slots can be allocated according to the interference power value of the adjacent cell, and interference between cells can be reduced. [0031] (12) In one aspect of the control station according to the present invention, the interference power calculation unit multiplies the downlink transmission power by a coefficient corresponding to an attenuation, and calculates the downlink transmission power multiplied by the coefficient. The addition is performed for each slot.
[0032] このように、基地局の干渉レベルを考慮した干渉電力値を算出することができる。 [0032] In this way, it is possible to calculate the interference power value in consideration of the interference level of the base station.
[0033] (13)本発明に係る基地局の一態様において、前記干渉電力算出部は、減衰量に 応じた係数を前記ダウンリンク送信電力へ乗算し、前記係数を乗算したダウンリンク 送信電力をスロット毎に加算することを特徴とする。 [0033] (13) In one aspect of the base station according to the present invention, the interference power calculation unit multiplies the downlink transmission power by a coefficient corresponding to an attenuation, and calculates the downlink transmission power multiplied by the coefficient. The addition is performed for each slot.
[0034] このように、基地局の干渉レベルを考慮した干渉電力値を算出することができる。 [0034] In this way, it is possible to calculate the interference power value in consideration of the interference level of the base station.
[0035] (14)本発明に係る無線通信システムのスロット割当方法の一態様において、前記 干渉電力を算出するステップは、減衰量に応じた係数を前記ダウンリンク送信電力へ 乗算し、前記係数を乗算したダウンリンク送信電力をスロット毎に加算することを特徴 とする。 [0035] (14) In one aspect of the slot allocation method of the wireless communication system according to the present invention, the step of calculating the interference power multiplies the downlink transmission power by a coefficient corresponding to an attenuation amount, and The downlink transmission power multiplied is added for each slot.
[0036] このように、基地局の干渉レベルを考慮した干渉電力値を算出することができる。  [0036] In this way, it is possible to calculate the interference power value in consideration of the interference level of the base station.
[0037] (15)本発明に係る無線通信システムの一態様は、複数の隣接するセル間で同一 周波数を用い、移動局が存在する複数のセルが隣接し、複数のスロットから構成され るフレームを用いてセル内の移動局と無線通信する複数の基地局を管理する制御 局を備える無線通信システムであって、前記基地局または前記制御局の!、ずれかよ つて、複数のセルそれぞれの基地局力も各スロットに割り当てられたダウンリンク送信 電力を収集し、前記収集したダウンリンク送信電力のうち、特定のセルに隣接する一 つ以上のセルのダウンリンク送信電力に基づいて干渉電力値を算出し、ダウンリンク 送信電力として要求される要求送信電力を前記特定のセルの基地局から取得し、前 記干渉電力値が小さ ヽスロットへ前記要求送信電力を割り当てることを特徴とする。 [0037] (15) An aspect of the wireless communication system according to the present invention is a frame in which a plurality of adjacent cells use the same frequency, a plurality of cells in which a mobile station exists are adjacent, and are configured from a plurality of slots. A wireless communication system comprising a control station that manages a plurality of base stations that wirelessly communicate with mobile stations in a cell using a base station of each of the plurality of cells depending on! The station power also collects the downlink transmission power allocated to each slot, and calculates the interference power value based on the downlink transmission power of one or more cells adjacent to a specific cell out of the collected downlink transmission power. Then, the requested transmission power required as the downlink transmission power is obtained from the base station of the specific cell, and the requested transmission power is allocated to the slot having the small interference power value. The features.
[0038] このように、この無線通信システムの制御局あるいは基地局の 、ずれかにお!/、て、 ダウンリンク通信に要求される要求送信電力を隣接セルのダウンリンク送信電力が小 さ 、スロットへ割り当てるので、隣接セルのダウンリンク送信電力に応じて適応的にス ロットを割り当てて、セル間干渉を削減することが可能となる。また、隣接セルのダウン リンク送信電力を用いて干渉電力値を算出するので、隣接セルの干渉電力値に応じ てスロットを割り当てることが可能となり、セル間の干渉を削減することができる。 発明の効果 [0038] In this way, the required transmission power required for the downlink communication is less than that of the control station or base station of this wireless communication system, and the downlink transmission power of the adjacent cell is small. Since it is assigned to the slot, it becomes possible to adaptively assign the slot according to the downlink transmission power of the adjacent cell and reduce inter-cell interference. In addition, since the interference power value is calculated using the downlink transmission power of the adjacent cell, slots can be allocated according to the interference power value of the adjacent cell, and interference between cells can be reduced. The invention's effect
[0039] 本発明によれば、隣接セルのダウンリンク送信電力に応じてスロットを割り当てること ができる。これにより、セル間干渉を削減することが可能となる。  [0039] According to the present invention, it is possible to assign a slot according to the downlink transmission power of an adjacent cell. Thereby, it becomes possible to reduce inter-cell interference.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0040] 次に、本発明の実施の形態について、図面を参照しながら説明する。各図面にお いて同一の構成または機能を有する構成要素および相当部分には、同一の符号を 付し、その説明は省略する。 Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, components having the same configuration or function and corresponding parts are denoted by the same reference numerals, and description thereof is omitted.
[0041] (第 1の実施形態） [0041] (First embodiment)
以下、本発明に係る無線通信システムの第 1の実施形態について説明する。先ず Hereinafter, a first embodiment of a wireless communication system according to the present invention will be described. First
、本発明の実施形態が適用される通信方式およびシステム構成について説明する。 本発明の第 1の実施形態における基本となる通信方式は TDMA (Time Division Multiple Access方式 3;たは FDMA (Frequency Division Multiple Acc ess)方式である。 The communication system and system configuration to which the embodiment of the present invention is applied will be described. The basic communication system in the first embodiment of the present invention is a TDMA (Time Division Multiple Access system 3) or FDMA (Frequency Division Multiple Access) system.
[0042] TDMA方式とはデータの送受信を行なう際、同一周波数帯域を短い時間に分割 し、分割された短 、時間区間を異なるユーザーに割り当てて無線通信を行なうァクセ ス方式である。通常、無線通信はフレーム (Frame)と呼ばれる時間区間を一定周期 で繰り返し送受信することにより無線通信を行なうが、 TDMA方式においては、フレ ームをいくつかに分割した時間スロットもしくは TTI (Transmission Time Interva 1)と呼ばれる短い時間区間を複数の移動局に割り当てることによって同時に複数の 移動局と基地局との間で無線通信を行なうアクセス方式である。  [0042] The TDMA scheme is an access scheme in which the same frequency band is divided into short times when data transmission / reception is performed, and wireless communication is performed by assigning the divided short and time sections to different users. Normally, wireless communication is performed by repeatedly transmitting and receiving a time interval called a frame at a constant cycle. In the TDMA system, a time slot or TTI (Transmission Time Interva This is an access method in which wireless communication is performed between a plurality of mobile stations and a base station at the same time by assigning a short time interval called 1) to a plurality of mobile stations.
[0043] 一方、 FDMA方式とはデータの送受信を行なう際、前述したある時間区間であるフ レームを周波数スロットと呼ばれる周波数方向に一定の帯域幅に分割した周波数帯 域を複数の移動局が同時に使用して無線通信を行なうアクセス方式である。  [0043] On the other hand, in the FDMA scheme, when transmitting and receiving data, a plurality of mobile stations simultaneously divide a frequency band obtained by dividing a frame, which is a certain time interval, into a certain bandwidth in a frequency direction called a frequency slot. It is an access method for performing wireless communication using it.
[0044] TDMA方式および FDMA方式における各スロットには、 64QAM、 16QAM、 QP SK、 BPSKなどの変調と符号ィ匕率と周波数方向および時間軸方向に適応的に拡散 率を変化させる拡散を同時に使用することが可能であり、各スロットに割り当てられた 移動局の伝搬路環境に応じた方式で無線通信を行なうことが可能である。以降、本 明細書では前記 3つの組み合わせを変調方式と呼ぶ。 [0045] 以下、本発明の実施形態における TDMA方式および FDMA方式のフレーム構成 に関して説明する。図 1は、フレーム構成の一例を示す図である。 [0044] For each slot in the TDMA and FDMA systems, 64QAM, 16QAM, QP SK, BPSK, etc., modulation, code rate, and spreading that adaptively changes the spreading rate in the frequency and time axis directions are used simultaneously. Wireless communication can be performed by a method according to the propagation path environment of the mobile station assigned to each slot. Hereinafter, the three combinations are referred to as modulation schemes in this specification. [0045] Hereinafter, a frame configuration of the TDMA scheme and the FDMA scheme in the embodiment of the present invention will be described. FIG. 1 is a diagram illustrating an example of a frame configuration.
[0046] TDMA通信方式においてはある一定時間区間のフレームを時間軸方向に分割し それぞれを別々の移動局に割り当ててデータ伝送に用いることが可能である。分割 された時間区間の最小単位を本明細書ではこれを時間スロットと称している。図 1 (a) に一般的な TDMA方式のフレーム構成の一例を示した。同図の場合ではスロット数 は 8になっている。一般的にはフレーム先頭のスロットに各スロットの移動局割当情報 および変調方式および報知情報などの全移動局に通知するための情報データが含 まれた制御スロットが設定されている。その他のスロットにはトラフィックデータ、移動 局固有制御情報、伝搬路推定用の既知情報などが割り当てられ送信される。  [0046] In the TDMA communication system, it is possible to divide a frame in a certain time interval in the time axis direction and assign each to a different mobile station for use in data transmission. In this specification, the minimum unit of the divided time interval is referred to as a time slot. Figure 1 (a) shows an example of a general TDMA frame structure. In the case of the figure, the number of slots is 8. In general, a control slot including information data for notifying all mobile stations such as mobile station allocation information of each slot and modulation scheme and broadcast information is set in the slot at the head of the frame. Traffic data, mobile station specific control information, known information for propagation path estimation, etc. are allocated to other slots and transmitted.
[0047] FDMA方式においてはある短い一定期間のフレームの全ての周波数帯域を分割 しそれぞれを別々の移動局に割り当ててデータ伝送に用いることが可能である。また 、分割された周波数区間の最小単位を本明細書では周波数スロットと称している。図 1 (b)に一般的な FDMA方式のフレーム構成の一例を示した。同図の場合にはスロ ット数は 12になっている。本発明の実施例における TDMA方式ではスロット数を 16 、さらに各移動局のスロット割当情報および変調方式および報知情報などの全移動 局に通知するための情報データが含まれた制御スロットを先頭のスロットに設定して いる。ただし、制御スロットの位置はそれに限るものではない。その他のスロットにはト ラフィックデータ、移動局固有制御情報、伝搬路推定用の既知情報などが割り当てら れ送信される。  [0047] In the FDMA scheme, it is possible to divide all frequency bands of a frame of a certain short period and assign them to different mobile stations for use in data transmission. Further, the minimum unit of the divided frequency section is referred to as a frequency slot in this specification. Figure 1 (b) shows an example of a general FDMA frame structure. In the figure, the number of slots is 12. In the TDMA scheme in the embodiment of the present invention, the number of slots is 16, and the control slot including information data for notifying all mobile stations such as slot allocation information, modulation scheme and broadcast information of each mobile station is the first slot. Is set. However, the position of the control slot is not limited to that. The other slots are assigned traffic data, mobile station specific control information, known information for channel estimation, etc., and are transmitted.
[0048] TDMA通信方式および FDMA通信方式のスロットは、 1つの移動局へ 1フレーム に 1スロットのみ割り当てる必要は無ぐ 1移動局が 1フレーム内で複数のスロットを占 有して無線通信を行なうことも可能である。  [0048] It is not necessary to allocate only one slot to one mobile station per slot for the TDMA communication system and the FDMA communication system. One mobile station occupies multiple slots in one frame and performs radio communication. It is also possible.
[0049] 図 2は、本発明の実施形態の無線通信システムの構成例を示した図である。当該 システムは、基地局制御局（「基地局制御局」は「制御局」ともいう） 100、基地局 200 a〜200d、移動局 300a〜3001が階層的に構成されるシステムである。本明細書で は、同じ構成要素が複数存在し、それぞれを区別する場合に、符号に接尾辞を付加 して、複数の構成要素それぞれを区別するものとする。例えば、図 2では、基地局 20 0a、 200b, 200c, 200dは、複数の基地局をそれぞれ区另 Uし、基地局 200とした場 合には、基地局のいずれか一つまたは複数を示すものとする。移動局 300について も同様である。 FIG. 2 is a diagram showing a configuration example of a radio communication system according to the embodiment of the present invention. This system is a system in which base station control stations (“base station control station” is also referred to as “control station”) 100, base stations 200a to 200d, and mobile stations 300a to 3001 are hierarchically configured. In this specification, when there are a plurality of the same constituent elements and they are distinguished from each other, a suffix is added to the code to distinguish each of the plurality of constituent elements. For example, in FIG. 0a, 200b, 200c, and 200d indicate one or more of the base stations when the base station 200 is divided into a plurality of base stations. The same applies to the mobile station 300.
[0050] 基地局制御局 100は、複数の基地局 200と接続し、各基地局 200を制御する。各 基地局 200は、セル内に存在する複数の移動局 300と無線通信によって接続し、移 動局を管理する。各移動局 300は、当該基地局 200からの制御情報を基にデータの 送受信を行なう。基地局制御局 100と基地局 200との間の通信は、有線通信と無線 通信とのどちらでも力まわない。移動局 300は、無線機、携帯電話等の無線通信を 行なう携帯できる端末 (携帯端末)を含む。  [0050] Base station control station 100 is connected to a plurality of base stations 200 and controls each base station 200. Each base station 200 is connected to a plurality of mobile stations 300 existing in the cell by wireless communication, and manages the mobile stations. Each mobile station 300 transmits and receives data based on control information from the base station 200. The communication between the base station control station 100 and the base station 200 cannot be performed by either wired communication or wireless communication. The mobile station 300 includes a portable terminal (mobile terminal) that performs wireless communication such as a wireless device and a mobile phone.
[0051] 図 3は、第 1の実施形態の基地局制御局の構成例を示すブロック図である。図 3に 示すように基地局制御局 100は、各基地局 200から通知される制御情報を取得 (受 信)する制御局取得部 110と、各基地局 200から通知された制御情報に基づいて、 各基地局 200を制御する制御情報処理部 120と、制御情報処理部 120が制御した 制御結果を各基地局 200へ通知（送信)する制御局通知部 130とを備える。制御情 報には、移動局 300が送信にあたって要求する要求送信電力、基地局 200が移動 局 300へデータを送信する際のダウンリンク送信電力その他各基地局 200とやり取り する情報が含まれる。また、制御結果は、制御情報処理部 120が制御した結果、例 えば、後述する割当情報を含む。  [0051] FIG. 3 is a block diagram illustrating a configuration example of the base station control station of the first embodiment. As shown in FIG. 3, the base station control station 100 is based on the control station acquisition unit 110 that acquires (receives) control information notified from each base station 200, and the control information notified from each base station 200. A control information processing unit 120 that controls each base station 200; and a control station notification unit 130 that notifies (transmits) the control result controlled by the control information processing unit 120 to each base station 200. The control information includes requested transmission power requested by the mobile station 300 for transmission, downlink transmission power when the base station 200 transmits data to the mobile station 300, and other information exchanged with each base station 200. The control result includes a result of control by the control information processing unit 120, for example, allocation information described later.
[0052] 制御情報処理部 120は、送信電力記憶部 121、干渉電力算出部 122並びに割当 部 123を備える。送信電力記憶部 121は、制御局 100が管理する複数のセルそれぞ れについて、各スロットに割り当てられたダウンリンク送信電力を各セルと対応づけた 送信電力情報を記憶する。各セルのダウンリンク送信電力は、セルに配置された各 基地局 200から基地局制御局 100へ通知される。送信電力情報は、セルを識別する セル識別子と対応づけて記憶される。割当部 123は、送信電力記憶部 121に記憶さ れた送信電力情報と、基地局 200から取得した要求送信電力とを用いてスロットの割 当を行なう。なお、送信電力記憶部 121は、一時的に送信電力情報を記憶する領域 であってもよい。たとえば、スロット割当を実施するときにのみ確保される記憶領域で あってもよい。従って、送信電力情報を記憶する記憶領域を確保する仕組みが備え られて 、ればよ!/、ことになる。 The control information processing unit 120 includes a transmission power storage unit 121, an interference power calculation unit 122, and an allocation unit 123. For each of a plurality of cells managed by control station 100, transmission power storage section 121 stores transmission power information in which the downlink transmission power assigned to each slot is associated with each cell. The downlink transmission power of each cell is reported to the base station control station 100 from each base station 200 arranged in the cell. The transmission power information is stored in association with a cell identifier that identifies a cell. Allocation section 123 performs slot allocation using transmission power information stored in transmission power storage section 121 and requested transmission power acquired from base station 200. The transmission power storage unit 121 may be an area for temporarily storing transmission power information. For example, it may be a storage area secured only when slot allocation is performed. Therefore, a mechanism for securing a storage area for storing transmission power information is provided. You should be! /
[0053] 干渉電力算出部 122は、特定のセルに隣接する一つ以上のセルのダウンリンク送 信電力をスロット毎に加算することにより、スロット毎の干渉電力値を算出する。ここで の干渉電力とは隣接する各基地局と自基地局との距離を考慮したスロット毎の送信 電力の和であり、セル内での各移動局の受信する干渉電力とは異なるものである。  [0053] Interference power calculation section 122 calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot. The interference power here is the sum of transmission power for each slot considering the distance between each adjacent base station and its own base station, and is different from the interference power received by each mobile station in the cell. .
[0054] 割当部 123は、干渉電力算出部 122が算出した干渉電力値を用いて、干渉電力 値が所定の値と比較して小さいスロットへ受信した要求送信電力を割り当てる。本実 施形態では、要求送信電力が大きい（高い)順に、干渉電力値が小さいスロットへ順 番に割り当てていく。割当部 123は、要求送信電力と、割り当てたスロットのスロット番 号とを対応づけた割当情報を作成する。  [0054] Assigning section 123 uses the interference power value calculated by interference power calculating section 122 to allocate the requested transmission power received to a slot whose interference power value is smaller than a predetermined value. In this embodiment, the slots are assigned in order from the smallest (highest) requested transmission power to the slots with the smallest interference power value. Allocation unit 123 creates allocation information in which the requested transmission power is associated with the slot number of the allocated slot.
[0055] 図 4は、第 1の実施形態の基地局の構成例を示すブロック図である。基地局 200は 、基地局制御局 100に要求送信電力やダウンリンク送信電力などの制御情報を基地 局制御局 100へ通知 (送信)する基地局通知部 210と、制御情報を用いて基地局制 御局 100が制御した制御結果を取得 (受信)する基地局取得部 220と、移動局 300 に無線データを送信する送信部 230と、移動局 300からの無線データを受信する受 信部 240と、基地局制御局 100および各移動局 300から通知された情報を処理する 移動局制御部 250とを備え、無線データはアンテナ部 260を介して各移動局 300と 送受信される。また、移動局制御処理部 250は、スケジューリング部 251と電力制御 部 252とを備える。スケジューリング部 251は、各スロットへ移動局 300を割り当てる。 本実施形態では、基地局制御局 100から通知される割当情報を用いて各移動局 30 0をスロットに割り当てる。詳細は後述する。電力制御部 252は、スケジューリング部 2 51の結果に基づいて各スロットのダウンリンク送信電力を制御する。  [0055] FIG. 4 is a block diagram illustrating a configuration example of the base station according to the first embodiment. The base station 200 includes a base station notifying unit 210 that notifies (transmits) control information such as required transmission power and downlink transmission power to the base station control station 100, and base station control using the control information. A base station acquisition unit 220 that acquires (receives) control results controlled by the control station 100, a transmission unit 230 that transmits wireless data to the mobile station 300, and a reception unit 240 that receives wireless data from the mobile station 300. Mobile station control section 250 that processes information notified from base station control station 100 and each mobile station 300, and wireless data is transmitted / received to / from each mobile station 300 via antenna section 260. In addition, the mobile station control processing unit 250 includes a scheduling unit 251 and a power control unit 252. Scheduling section 251 assigns mobile station 300 to each slot. In the present embodiment, each mobile station 300 is allocated to a slot using allocation information notified from the base station control station 100. Details will be described later. The power control unit 252 controls the downlink transmission power of each slot based on the result of the scheduling unit 251.
[0056] 図 5は、第 1の実施形態の移動局の構成例を示すブロック図を示す。移動局 300は 基地局 200から送信された無線データを受信する受信部 310と、無線データを基地 局 200へ送信する送信部 320と、受信した無線データを処理する情報処理部 330と を備え、無線データをアンテナ部 340から送受信する。さらに、移動局 300は、基地 局 200からダウンリンク（下り方向）送信された無線データの受信電力レベルを測定 する受信電力測定部 350を備え、前記の測定結果から算出される伝搬路品質情報 をアップリンク（上り方向）無線通信により基地局 200に通知する。 [0056] FIG. 5 is a block diagram illustrating a configuration example of the mobile station according to the first embodiment. The mobile station 300 includes a receiving unit 310 that receives wireless data transmitted from the base station 200, a transmitting unit 320 that transmits wireless data to the base station 200, and an information processing unit 330 that processes the received wireless data. Wireless data is transmitted and received from the antenna unit 340. Furthermore, the mobile station 300 includes a reception power measurement unit 350 that measures the reception power level of radio data transmitted from the base station 200 in the downlink (downlink direction), and propagation path quality information calculated from the measurement result. To the base station 200 through uplink (uplink) wireless communication.
[0057] 以下に、本発明の第 1の実施形態におけるスロット割当の手順および動作を説明 する。第 1の実施形態のスロット割当方法の概略は、次のとおりである。ここでは図 2 に示した、複数のセルそれぞれに設置される移動局 300と、各セルに存在する移動 局 300を制御する複数の基地局 200と、複数の基地局 200を管理する基地局制御 局 100から構成される無線通信システムを用いる。複数の基地局 200は、各移動局 3 00から受信したダウンリンク伝搬路品質情報を考慮して、ダウンリンク送信電力を決 定し、基地局制御局 100は、決定したダウンリンク送信電力を受け取り、隣接セルか らの電波による干渉量を低減するように、各移動局 300が使用するスロットのダウンリ ンク送信電力を適応的に割り当てる。  [0057] The procedure and operation of slot allocation in the first embodiment of the present invention will be described below. The outline of the slot allocation method of the first embodiment is as follows. Here, as shown in FIG. 2, mobile station 300 installed in each of a plurality of cells, a plurality of base stations 200 controlling mobile stations 300 existing in each cell, and a base station control managing a plurality of base stations 200 A wireless communication system composed of station 100 is used. Multiple base stations 200 determine downlink transmission power in consideration of downlink channel quality information received from each mobile station 300, and base station control station 100 receives the determined downlink transmission power. Then, the downlink transmission power of the slot used by each mobile station 300 is adaptively allocated so as to reduce the amount of interference due to radio waves from neighboring cells.
[0058] また、基地局制御局 100が要求送信電力を割り当てるスロットは、基地局制御局 10 0と基地局 200間の情報量を低減するために、ある一定値以上のダウンリンク送信電 力が必要なスロットのみスロット割当を行なうようにする。送信電力割当作業を行なう 要求送信電力の閾値は、制御する基地局数およびスロット数などの情報量の増減に 関与する要素、即ち基地局制御局 100と複数の基地局 200との間の情報量および 情報処理能力によって決定することが望ま 、。  [0058] In addition, the slot to which the base station control station 100 allocates the requested transmission power has a downlink transmission power of a certain value or more in order to reduce the amount of information between the base station control station 100 and the base station 200. Slot allocation is performed only for necessary slots. Performing transmission power allocation work The threshold of requested transmission power is the factor involved in the increase / decrease in the amount of information such as the number of controlled base stations and the number of slots, that is, the amount of information between the base station control station 100 and a plurality of base stations 200. And hope to be determined by information processing ability.
[0059] 以上の処理の後、基地局 200は、基地局制御局 100から通知された割当情報を用 いて閾値より大きいダウンリンク送信電力が必要な移動局 300ヘスロットを割り当て、 割り当てたスロット以外の中で、閾値以下のダウンリンク送信電力が必要な移動局 30 0ヘスロットを割り当てる。基地局 200は割当結果 (割当情報）に基づき移動局 300毎 のデータをスケジューリングし、無線データを送信する。このような基地局制御局 100 による適応スロット割当を行なう場合の割当の詳細について以下に説明する。  [0059] After the above processing, the base station 200 allocates a slot to the mobile station 300 that requires a downlink transmission power larger than the threshold using the allocation information notified from the base station control station 100, and other than the allocated slot. Among them, a slot is allocated to a mobile station 300 that requires downlink transmission power equal to or less than a threshold value. Base station 200 schedules data for each mobile station 300 based on the allocation result (allocation information) and transmits radio data. Details of allocation when adaptive slot allocation is performed by the base station control station 100 will be described below.
[0060] 以下の説明では、本発明の一態様として、スロット割当方法を携帯電話の無線通信 システムへ適用し、移動局 300の一例として端末 (携帯端末)を用いて説明する。ま た、第 1の実施形態によるスロット構成は図 1 (a)に示した TDMA方式のシステム〖こ おけるスロット構成を例に説明を行なう。但し、前述したような FDMA方式における周 波数方向のスロットを TDMA方式の時間軸方向のスロットとして扱うことにより同様の 効果を得ることが出来る。無線通信システムの構成は、図 2と同様である。 [0061] 第 1の実施形態では、各基地局 200が同期したシステム、すなわち各基地局 200 でフレームを送信するタイミングが同時になるように設計されたシステムである。その 同期方法に関しては一般的には GPS (Global Positioning System)を利用した 同期方法が良く知られているが、ここでは説明を省略する。次いで、本実施形態の説 明に用いるセル配置状況等にっ 、て説明する。 In the following description, as an aspect of the present invention, the slot allocation method is applied to a wireless communication system of a mobile phone, and a terminal (mobile terminal) is described as an example of the mobile station 300. The slot configuration according to the first embodiment will be described by taking the slot configuration in the TDMA system shown in FIG. 1 (a) as an example. However, the same effect can be obtained by treating the slots in the frequency direction in the FDMA system as described above as slots in the time axis direction of the TDMA system. The configuration of the wireless communication system is the same as in FIG. [0061] The first embodiment is a system in which each base station 200 is synchronized, that is, a system designed so that the timing at which each base station 200 transmits a frame is the same. As for the synchronization method, a synchronization method using GPS (Global Positioning System) is generally well known, but the description is omitted here. Next, the cell arrangement status used for the description of this embodiment will be described.
[0062] 図 6は、セルとセル内に存在する端末配置についての典型的な例を示した図であ る。図 6では、端末 A〜Fがセル 1内に存在する場合を示している。また、セル 1は、基 地局 200aが配置されている。図 7は、セル 1内の各端末 A〜Fに関して要求送信電 力の大きさの相対関係を示す図である。図 7では、端末 Fの要求送信電力が最大で あり、端末 Dの要求送信電力が最小となる例である。また、閾値 P は、ダウンリンク  FIG. 6 is a diagram showing a typical example of a cell and terminal arrangement existing in the cell. FIG. 6 shows a case where terminals A to F exist in cell 1. In cell 1, base station 200a is arranged. FIG. 7 is a diagram showing the relative relationship between the magnitudes of the requested transmission powers for the terminals A to F in the cell 1. FIG. 7 shows an example in which the required transmission power of terminal F is the maximum and the required transmission power of terminal D is the minimum. Threshold P is the downlink
TH  TH
送信電力の設定を基地局制御局 100で行なうか否かを判断する閾値である。閾値 P  This is a threshold value for determining whether or not the transmission power is set by the base station control station 100. Threshold P
THより大きなダウンリンク送信電力を必要とする端末は、基地局制御局 100によって ダウンリンク送信電力の設定を行なう。閾値 P の値はセルサイズ、基地局 200と基 A terminal that requires a downlink transmission power larger than TH sets the downlink transmission power by the base station control station 100. The value of threshold P is the cell size, base station 200,
TH  TH
地局制御局 100間の情報処理量などに関連して変更することが望ましい。図 8は、第 1の実施形態で用いるフレーム構成例を示す図である。図 8に示すフレーム構成では 、全スロット数が 16であり、制御スロット（スロット番号 0)、時間スロット数を 15とし、全 セルで同一周波数帯を用いる構成とする。  It is desirable to change in relation to the amount of information processing between the local station control stations 100. FIG. 8 is a diagram illustrating a frame configuration example used in the first embodiment. In the frame configuration shown in FIG. 8, the total number of slots is 16, the number of control slots (slot number 0), the number of time slots is 15, and the same frequency band is used in all cells.
[0063] 図 9は、複数のセルと端末配置の関係を示す図である。図 9では、図 6に示したセル 1がセル 2並びにセル 3と隣接する状態を示す。セル 2は、基地局 200bと、端末 H〜 Nが配置され、セル 3は、基地局 200cと端末 0〜Uが配置されている。ここで図 9の セル 2およびセル 3に関しては既に本発明の第 1の実験形態と同様の方法によりスロ ット割当が行なわれていることを前提とする。図 10は、セル 2内の各端末 H〜Nに関 して要求送信電力の大きさの相対関係を示している。図 11は、セル 3内の各端末 O 〜Uに関して要求送信電力の大きさの相対関係を示している。各セルの端末は、図 12、図 13に示したようなスロット割当状況となっているものとする。図 12は、セル 2内 の各端末 H〜Nのスロット割当状況を示す図であり、図 13は、セル 3内の各端末 0〜 Uのスロット割当状況を示す図である。以下では、図 9のセル 1の各端末 (移動局 300 )の伝搬路状況からスロット割当を行なう例を説明する。すなわち、セル 1が特定のセ ルに相当する。特定のセルは、スロット割当を要求する基地局が存在するセル (スロッ ト割当要求セル)である。 FIG. 9 is a diagram showing a relationship between a plurality of cells and terminal arrangement. FIG. 9 shows a state in which cell 1 shown in FIG. 6 is adjacent to cell 2 and cell 3. In cell 2, base station 200b and terminals H to N are arranged, and in cell 3, base station 200c and terminals 0 to U are arranged. Here, it is assumed that slots 2 and 3 in FIG. 9 have already been assigned slots by the same method as in the first experimental embodiment of the present invention. FIG. 10 shows the relative relationship between the required transmission power levels for the terminals H to N in the cell 2. FIG. 11 shows the relative relationship between the required transmission power levels for the terminals O to U in the cell 3. It is assumed that the terminals of each cell are in the slot allocation situation as shown in FIGS. FIG. 12 is a diagram showing the slot allocation status of each terminal H to N in the cell 2, and FIG. 13 is a diagram showing the slot allocation status of each terminal 0 to U in the cell 3. In the following, an example in which slot allocation is performed based on the propagation path status of each terminal (mobile station 300) in cell 1 in FIG. 9 will be described. That is, cell 1 has a specific cell Equivalent to The specific cell is a cell (slot allocation request cell) in which a base station requesting slot allocation exists.
[0064] 次 、で、ダウンリンク無線データのスロット割当（スケジューリング）に関して説明する 。図 14は、第 1の実施形態におけるスロット割当の一例を示すシーケンス図である。 図 14では、基地局制御局 100、基地局 200並びに移動局 300の間のシーケンスを 示す。移動局 300の動作は、端末 A〜Gそれぞれの動作を示すものである。動作の 説明において、セル 1の移動局 300と記した場合、端末 A〜Gの全部、あるいは、い ずれか一つ以上の端末を指すものとする。  Next, slot allocation (scheduling) of downlink radio data will be described. FIG. 14 is a sequence diagram showing an example of slot allocation in the first embodiment. FIG. 14 shows a sequence among the base station control station 100, the base station 200, and the mobile station 300. The operation of the mobile station 300 shows the operation of each of the terminals A to G. In the description of the operation, when the mobile station 300 of the cell 1 is described, it means all of the terminals A to G or one or more terminals.
[0065] まず、予め、基地局制御局 100は、セル 2並びにセル 3について、制御局取得部 1 10が各基地局 200 (ここでは、基地局 200b、 200c)力 ダウンリンク送信電力を取 得し、スロット毎のダウンリンク送信電力を送信電力記憶部 121に記憶する (ステップ S10)。この動作は、セル 2並びにセル 3のスロット割当後に、各基地局 200からダウ ンリンク送信電力が通知されることによって、あるいは、セル 1のスロット割当の前に基 地局制御局 100がダウンリンク送信電力を収集することによって、実施する。  [0065] First, for base station control station 100, for base station 2 and base station 3, control station acquisition section 110 acquires the base station 200 (here, base stations 200b and 200c) power downlink transmission power. Then, the downlink transmission power for each slot is stored in the transmission power storage unit 121 (step S10). This operation is performed when the downlink transmission power is notified from each base station 200 after cell 2 and cell 3 slot allocation, or before the base station control station 100 performs downlink transmission before cell 1 slot allocation. Implement by collecting power.
[0066] 各基地局 200は、定期的に制御情報を移動局 300へ送信する (ステップ Sl l)。セ ル 1内にある移動局 300において通信要求が発生しスロット割当機会を得た場合、 各移動局 300は、基地局 200から定期的に送信される制御信号を受信する。各移動 局 300は、受信した信号の受信電力レベルを測定し (ステップ S 12)、さらに受信信 号を復調すること (ステップ S 13)によって、基地局 200から送信された制御情報 (制 御信号)を得る (ステップ S 14)。制御情報は、基地局 200から一定期間ごとに送信さ れており、そのダウンリンク送信電力は移動局 300がセルエッジ付近に位置している 場合においても受信可能な電力および変調方式に設定されている。制御スロットに て送信される制御情報には、制御情報を送信した制御スロットの送信電力、各移動 局 300のスロット割当情報が含まれているものとする。  [0066] Each base station 200 periodically transmits control information to the mobile station 300 (step Sl l). When a communication request is generated in the mobile station 300 in the cell 1 and a slot allocation opportunity is obtained, each mobile station 300 receives a control signal periodically transmitted from the base station 200. Each mobile station 300 measures the received power level of the received signal (step S 12), and further demodulates the received signal (step S 13), thereby transmitting control information (control signal) transmitted from the base station 200. ) (Step S14). The control information is transmitted from the base station 200 at regular intervals, and the downlink transmission power is set to the power and modulation scheme that can be received even when the mobile station 300 is located near the cell edge. . It is assumed that the control information transmitted in the control slot includes transmission power of the control slot that transmitted the control information and slot allocation information of each mobile station 300.
[0067] 次に、移動局 300は、復調信号から得られたダウンリンク送信電力と受信電カレべ ルから伝搬路における電波の減衰量である伝搬損を算出する。伝搬損を算出する式 を以下に示す。  [0067] Next, mobile station 300 calculates a propagation loss, which is the amount of radio wave attenuation in the propagation path, from the downlink transmission power and the received power level obtained from the demodulated signal. The equation for calculating the propagation loss is shown below.
[0068] 伝搬損 =ダウンリンク送信電力 受信電力レベル （式 1) 移動局 300は、式 1により求められた伝搬損を基に要求送信電力と変調方式を導 出する (ステップ S15)。要求送信電力と変調方式の導出に関する詳細な説明は省 略する。移動局 300は、要求送信電力と変調方式をアップリンク送信にて基地局 20 0に通知する (ステップ S17)。この際、移動局 300が基地局 200と連続した通信を行 なっている場合には要求送信電力の通知方法を現在基地局とのダウンリンク送信に 使用している電力レベルとの差分の値、もしくは増減を表すビットなどにより通知する ことも可能である。基地局 200は、移動局 300から要求送信電力と変調方式が通知 されることにより、各移動局 300の伝搬路品質情報を取得する。この間、基地局 200 は、既に割当済みの端末にはデータを送信している (ステップ S16)。 [0068] Propagation loss = downlink transmission power received power level (Equation 1) The mobile station 300 derives the required transmission power and the modulation scheme based on the propagation loss obtained from Equation 1 (step S15). A detailed description of the required transmission power and modulation method derivation is omitted. The mobile station 300 notifies the requested transmission power and modulation scheme to the base station 200 through uplink transmission (step S17). At this time, when the mobile station 300 is continuously communicating with the base station 200, the notification method of the requested transmission power is set to a difference value from the power level currently used for downlink transmission with the base station, It is also possible to notify by a bit indicating increase / decrease. The base station 200 obtains the propagation path quality information of each mobile station 300 by notifying the requested transmission power and modulation scheme from the mobile station 300. During this time, the base station 200 transmits data to terminals that have already been allocated (step S16).
[0069] 次に、基地局 200において、スケジューリング部 251は、要求送信電力と変調方式 の情報を取得し、各移動局 300の要求送信電力を閾値 P と比較し、基地局制御局 [0069] Next, in base station 200, scheduling section 251 obtains requested transmission power and modulation scheme information, compares the requested transmission power of each mobile station 300 with threshold P, and
TH  TH
100によってスケジューリングが必要な移動局を判定する (ステップ S18)。具体的に は、スケジューリング部 251は、閾値 P より大きい要求送信電力を必要とする移動  A mobile station that needs to be scheduled is determined by 100 (step S18). Specifically, the scheduling unit 251 moves that requires a required transmission power larger than the threshold value P.
TH  TH
局 300を抽出する。基地局通知部 210は、割当スロット数 (抽出した移動局 300の数 )とそれぞれの要求送信電力を基地局制御局 100に通知する (ステップ S19)。  Extract station 300. The base station notification unit 210 notifies the base station control station 100 of the number of allocated slots (the number of extracted mobile stations 300) and the respective requested transmission power (step S19).
[0070] ここで P とは前述したように移動局の要求送信電力に設定された閾値であるが、 [0070] Here, P is a threshold set to the requested transmission power of the mobile station as described above.
TH  TH
要求送信電力が大きい移動局 300にはそれに応じたダウンリンク送信電力を設定す ることが良好な無線通信を行なうために必要である。それゆえ、要求送信電力が大き い移動局に向けて送信される無線データはダウンリンク送信電力が大きくなり隣接す るセルに対する干渉も大きくなる。よって、大きな干渉を及ぼすダウンリンク送信電力 を必要とする移動局とそうでないものを分ける判断を行なうための値が P であり、設  The mobile station 300 having a large required transmission power needs to set a downlink transmission power corresponding to the mobile station 300 in order to perform good radio communication. Therefore, the radio data transmitted toward a mobile station having a large required transmission power has a large downlink transmission power and a large interference with adjacent cells. Therefore, P is the value for making a decision to distinguish between mobile stations that require downlink transmission power that causes significant interference and those that do not.
TH  TH
定セル半径の値、すなわち隣接セルの近さにより設定を変更すべき値である。また、 P を低く設定するほど基地局制御局 100で処理する移動局が増加するため、すな This is a value whose setting should be changed depending on the value of the constant cell radius, that is, the proximity of adjacent cells. Also, as P is set lower, the number of mobile stations processed by base station controller 100 increases.
TH TH
わち基地局 200から基地局制御局 100に通知する情報量が多くなることから P の  In other words, the amount of information to be notified from base station 200 to base station control station 100 increases.
TH  TH
値により基地局制御局との情報量を操作することが可能である。  The amount of information with the base station control station can be manipulated by the value.
[0071] 基地局制御局 100の制御局取得部 110は、基地局 200から割当スロット数と要求 送信電力を取得する。基地局制御局 100において、干渉電力算出部 122は、干渉 電力値を算出し、割当部 123は、基地局 200からの情報と送信電力記憶部 121に記 憶する送信電力情報を用いて、スロットのダウンリンク送信電力割当を行なう（ステツ プ S20)。 [0071] Control station acquisition section 110 of base station control station 100 acquires the number of assigned slots and the requested transmission power from base station 200. In base station control station 100, interference power calculation section 122 calculates an interference power value, and allocation section 123 stores information from base station 200 and transmission power storage section 121. Using the transmission power information stored, slot downlink transmission power allocation is performed (step S20).
[0072] 図 15は、複数のセルそれぞれのスロット毎のダウンリンク送信電力の和を示す図で ある。図 15では、セル 2は、スロット番号 1〜7へダウンリンク送信電力を割り当て、セ ル 3は、スロット番号 9〜15へダウンリンク送信電力を割り当てた例を示している。図 1 5に示すように、干渉電力算出部 122は、隣接セルの各基地局のダウンリンク送信電 力をスロット毎に加算することにより、スロット毎の干渉電力値を算出する。本実施形 態ではセル 2とセル 3の基地局力ゝらの送信波を干渉波として扱う場合に関して示した 力 干渉となる隣接基地局数が 3以上ある場合に関しても同様な方法で算出を行え る。但し、このとき割当を行なっているセルと物理的な距離の違いまたは地形的障害 などの要因で干渉レベルが最近接セルの基地局より低い基地局に関しては予め減 衰量に応じた係数を設定することが望ましい。従って、隣接セルの各基地局のダウン リンク送信電力をスロット毎に加算することには、各基地局毎に予め設定した減衰量 に応じた係数を、ダウンリンク送信電力へ乗算した値をダウンリンク送信電力としてカロ 算することも含まれる。また、本実施形態ではセル 2とセル 3で同時に使用しているス ロットはないが、 2つの基地局により同時に使用しているスロットがある場合にはセル 2 とセル 3のダウンリンク送信電力の和をそのスロットの総干渉電力値として扱う。  FIG. 15 is a diagram showing a sum of downlink transmission power for each slot of a plurality of cells. In FIG. 15, cell 2 shows an example in which downlink transmission power is assigned to slot numbers 1-7, and cell 3 shows an example in which downlink transmission power is assigned to slot numbers 9-15. As shown in FIG. 15, the interference power calculation unit 122 calculates the interference power value for each slot by adding the downlink transmission power of each base station of the adjacent cell for each slot. In this embodiment, the same method can be used to calculate the number of neighboring base stations that cause force interference as shown in the case of handling the transmission waves of the base station power of cell 2 and cell 3 as interference waves. The However, a coefficient corresponding to the amount of attenuation is set in advance for base stations whose interference level is lower than the base station of the nearest cell due to a difference in physical distance from the assigned cell or topographical failure. It is desirable to do. Therefore, in order to add the downlink transmission power of each base station in the adjacent cell for each slot, the downlink transmission power is multiplied by a value corresponding to the attenuation set in advance for each base station. It also includes calculating the transmission power. Also, in this embodiment, there are no slots used simultaneously in cell 2 and cell 3, but if there are slots used simultaneously by two base stations, the downlink transmission power of cell 2 and cell 3 The sum is treated as the total interference power value for that slot.
[0073] 次に、基地局制御局 100の割当部 123は、要求送信電力が最も大きい順に、スロ ットの割当を行なう（ステップ S20)。図 16にスロット割当手順の一例を示すフローチヤ ートを示す。制御局取得部 110は、基地局 200から要求送信電力を取得し (ステップ S31)、割当部 123へ受け渡す。割当部 123は、まず最も大きい要求送信電力が必 要なスロットを決定する (ステップ S32)。決定方法は、干渉波となる隣接基地局のダ ゥンリンク送信電力の和（すなわち、干渉電力値)の最も小さい未割当スロットに選択 したスロットを割り当てるものとする。最も大きい要求送信電力を要求した移動局 300 が使用するスロットから順に割り当て、次に大き 、要求送信電力を最も大き ヽ要求送 信電力に割当済みのスロット以外のスロット中で最も干渉電力値の総和が低くなるス ロットに割り当てる (ステップ S33)。すなわち、ダウンリンク送信電力が大きなスロット 力も順に干渉電力値の小さくなるスロットに割り当てられることになる。その後、以上の 作業を割り当てるべきスロットがなくなるまで続ける (ステップ S34)。 [0073] Next, allocating section 123 of base station control station 100 performs slot allocation in the order of the largest required transmission power (step S20). Figure 16 shows a flowchart showing an example of the slot allocation procedure. The control station acquisition unit 110 acquires the requested transmission power from the base station 200 (step S31) and passes it to the allocation unit 123. The allocating unit 123 first determines a slot that requires the largest requested transmission power (step S32). The decision method shall assign the selected slot to the unassigned slot with the smallest sum of downlink transmission powers (ie, interference power values) of adjacent base stations that become interference waves. The mobile station 300 that requested the largest requested transmission power is allocated in order from the slot used, and then the largest, the largest requested transmission power is the sum of the interference power values that are the largest among the slots other than the slots already allocated to the requested transmission power. Is assigned to a slot with a lower value (step S33). That is, the slot power with the large downlink transmission power is also assigned to the slots with the smaller interference power values in order. Then more Continue until there are no more slots to allocate work (step S34).
[0074] 割当が完了したところで各スロットに設定した送信電力情報 (割当情報、スケジユー リング情報）を基地局に通知する（ステップ S35、図 14のステップ S21)。 [0074] When the assignment is completed, the base station is notified of the transmission power information (assignment information, scheduling information) set for each slot (step S35, step S21 in Fig. 14).
[0075] 次に、基地局 200は、移動局 300のスケジューリングを行なう（ステップ S22)。基地 局 200における各移動局の割当方法を図 17のフローチャートに従って説明する。図 17は、基地局が各スロットへ移動局を割り当てる手順の一例を示すフローチャートで ある。基地局 200は、基地局制御局 100から取得した各スロットへ要求送信電力を割 り当てる割当情報をもとに各移動局 300の使用するスロットを割り当てる。割当情報に は、スロット番号と要求送信電力とが対応づけられている。従って、基地局 200は、要 求送信電力を要求した移動局 300をスロット番号へ対応づけることになる。また、基 地局 200では、スロットへ設定された要求送信電力を移動局 300とのダウンリンク通 信で用いるダウンリンク送信電力とする。スケジューリング部 251は、第 1段階として基 地局制御局 100に割当を行わせる判断基準となった閾値 P より要求送信電力の大 Next, base station 200 performs scheduling for mobile station 300 (step S22). The allocation method of each mobile station in the base station 200 will be described according to the flowchart of FIG. FIG. 17 is a flowchart showing an example of a procedure in which the base station assigns a mobile station to each slot. Base station 200 assigns a slot to be used by each mobile station 300 based on assignment information for assigning requested transmission power to each slot acquired from base station control station 100. In the allocation information, the slot number and the requested transmission power are associated. Therefore, the base station 200 associates the mobile station 300 that requested the requested transmission power with the slot number. Also, in the base station 200, the requested transmission power set for the slot is used as the downlink transmission power used in the downlink communication with the mobile station 300. Scheduling unit 251 has a larger required transmission power than threshold P, which is a determination criterion for assigning to base station control station 100 as a first step.
TH  TH
きい移動局 300から割当を行なう。基地局 200のスケジューリング部 251は、要求送 信電力が閾値 P より大きい移動局 300の中で要求送信電力の大きい順番に移動  Allocation starts from threshold mobile station 300. The scheduling unit 251 of the base station 200 moves in the order of the requested transmission power in the mobile station 300 whose requested transmission power is larger than the threshold value P.
TH  TH
局 300ヘスロット割当を行ない、次いで、第 2段階として、要求送信電力が閾値 P よ  Station 300 is assigned a slot, and then, as the second step, the requested transmission power is set to the threshold value P.
TH  TH
り小さ 、（低 、）の移動局 300の中で要求送信電力が大き!/、順番に移動局 300ヘス ロットを割り当てる。具体的には次の手順によって実施する。  The requested transmission power is large among the smaller (low) mobile stations 300! /, And slots are allocated to the mobile stations 300 in order. Specifically, the following procedure is performed.
[0076] 第 1段階として、スケジューリング部 251は、割り当てられていない移動局 300の中 で最も要求送信電力を要求した移動局 300を選択する (ステップ S41)。次に、要求 送信電力が閾値 P より大きい移動局 300の場合 (ステップ S42で Yes)、基地局制 [0076] As a first stage, scheduling section 251 selects mobile station 300 that has requested the requested transmission power most among unassigned mobile stations 300 (step S41). Next, in the case of mobile station 300 whose requested transmission power is greater than threshold P (Yes in step S42), base station control
TH  TH
御局 100から取得した割当情報において、選択された移動局の要求送信電力を満 たすスロットの中から最も要求送信電力の大き 、スロットを割り当てる（ステップ S43) 。順に要求送信電力の大きい移動局力 未割当スロットの中で最も大きい要求送信 電力が設定されたスロットに割り当てる (ステップ S41からステップ S43)。以上の段階 に関しては、移動局が要求した要求送信電力が基地局制御局 100によって決定され 、割当情報として基地局 200に通知されている。従って、フレーム内のいずれかのス ロットが要求送信電力に設定されて!、るため伝搬損が最も大き!、移動局 300から選 択することによりそのスロットとの対応が取れるようになる。 In the allocation information acquired from the control station 100, the slot having the largest required transmission power is allocated from the slots satisfying the required transmission power of the selected mobile station (step S43). In order, the mobile station power having the highest required transmission power is assigned to the slot in which the highest required transmission power is set among the unallocated slots (step S41 to step S43). With respect to the above steps, the requested transmission power requested by the mobile station is determined by the base station control station 100 and notified to the base station 200 as allocation information. Therefore, any slot in the frame is set to the required transmission power !, so the propagation loss is the largest! By selecting, the correspondence with the slot can be taken.
[0077] 次に、第 2段階として、要求送信電力が P 以下の移動局に関して順に割り当てて  [0077] Next, as a second stage, the mobile stations whose requested transmission power is P or less are assigned in order.
TH  TH
いく。閾値 P より大きい要求送信電力は、基地局制御局 100によってスロットが割り  Go. The requested transmission power greater than the threshold value P is allocated by the base station control station 100 as a slot.
TH  TH
当てられたが、閾値 P 以下の要求送信電力は、基地局制御局 100によってスロット  However, the requested transmission power below the threshold P is slotted by the base station controller 100.
TH  TH
が割り当てられていない。このため、要求送信電力が閾値 P 以下を要求した移動局  Is not assigned. Therefore, the mobile station that requested the requested transmission power to be below the threshold P
TH  TH
300の場合 (ステップ S42で No)、スケジューリング部 251は、ステップ S41で選択し たスロットを割り当てていない要求送信電力のうち、大きいものから順番に、前記第 1 段階で割り当てられたスロット以外の残りのスロットから割り当てるスロットを選択する（ ステップ S44)。以上のような手順に関して未割当移動局がなくなるまで行なう（ステツ プ S45で Noの場合、ステップ S41、ステップ S42、ステップ S44を繰り返す）。  In the case of 300 (No in step S42), the scheduling unit 251 proceeds from the request transmission power not allocated to the slot selected in step S41, in descending order, from the remaining slots other than the slot allocated in the first stage. The slot to be allocated is selected from the slots of (Step S44). The above procedure is repeated until there are no unassigned mobile stations (if step S45 is No, step S41, step S42, and step S44 are repeated).
[0078] スケジューリング部 251は、各スロットへ割り当てた要求送信電力をダウンリンク送信 電力として用いる。スロット割当結果は、送信部 230によって、制御スロットによりセル 内の移動局 300へ報知される（ステップ S46、図 14のステップ S24)。その後、割り当 てられたデータが所望の変調方式でダウンリンク送信される (ステップ S47、図 14の ステップ S25)。 [0078] Scheduling section 251 uses the requested transmission power allocated to each slot as the downlink transmission power. The slot allocation result is notified by the transmission unit 230 to the mobile station 300 in the cell through the control slot (step S46, step S24 in FIG. 14). Thereafter, the allocated data is transmitted in the downlink by a desired modulation method (step S47, step S25 in FIG. 14).
[0079] また、基地局 200でのダウンリンク送信電力（要求送信電力）の割当が終了した後、 基地局通知部 210は、各スロットに割り当てたダウンリンク送信電力とスロット番号とを 対応づけて基地局制御局 100へ通知する（図 14のステップ S23)。但し、この手順は 各移動局 300への制御情報送信およびデータ送信手順との順序を問わな 、。通知 を受けた基地局制御局 100では、制御局取得部 110がダウンリンク送信電力を取得 し、取得したダウンリンク送信電力をセル (セル識別子）と対応づけた送信電力情報と して送信電力記憶部 121へ書き込む。なお、送信電力情報の更新は、基地局 200か ら送信電力情報が通知された場合に限られない。定期的に各基地局 200からダウン リンク送信電力の通知を受け付ける場合や、基地局 200からスロット割当の要求を受 け付けたときに、ダウンリンク送信電力を各基地局 200から収集する場合であっても よい。  [0079] Further, after the allocation of the downlink transmission power (requested transmission power) in base station 200 is completed, base station notification section 210 associates the downlink transmission power allocated to each slot with the slot number. The base station control station 100 is notified (step S23 in FIG. 14). However, this procedure does not matter the order of the control information transmission and data transmission procedure to each mobile station 300. In the base station control station 100 that has received the notification, the control station acquisition unit 110 acquires the downlink transmission power, and stores the transmission power as transmission power information in which the acquired downlink transmission power is associated with a cell (cell identifier). Write to part 121. Note that the transmission power information is not updated when the transmission power information is notified from the base station 200. When receiving downlink transmission power notifications periodically from each base station 200, or when collecting downlink transmission power from each base station 200 when a slot allocation request is received from the base station 200. May be.
[0080] 以上のように行なわれたスロット割当の結果を図 18に示す。図 18の上段は、各セ ルそれぞれについて、スロット毎のダウンリンク送信電力の値を示す図であり、図 18 の下段は、セル 1のスロット割当の結果を示すフレーム構成図である。具体的には P FIG. 18 shows the result of slot assignment performed as described above. The upper part of FIG. 18 shows the values of downlink transmission power for each slot for each cell. The lower part is a frame configuration diagram showing the result of slot assignment for cell 1. Specifically, P
T  T
が図 7のように設定されていた場合、基地局制御局 100にてダウンリンク送信電力を Is set as shown in Fig. 7, the base station control station 100 sets the downlink transmission power.
H H
設定するのは端末 A、端末 B、端末 Fである。セル 1に配置された基地局 200aは、端 末 A、端末 B、端末 Fの使用スロット数とその要求送信電力とを基地局制御局 100に 報告する。この時、基地局制御局 100は隣接セル 2とセル 3の基地局 200b、 200c力 らのダウンリンク送信電力の情報を収集し (ある 、は収集した送信電力情報を送信電 力記憶部 121から読み出し）、スロット毎の総和を算出する。算出には基地局 200aと 周辺干渉局となる基地局 200b、 200cの距離を補正するような値を考慮するがこの 場合セル 2とセル 3は基地局力 等距離にあるので補正は行わなくて良い。  Terminal A, terminal B, and terminal F are set. Base station 200a arranged in cell 1 reports to base station control station 100 the number of slots used by terminal A, terminal B, and terminal F and their required transmission power. At this time, the base station control station 100 collects the downlink transmission power information from the base stations 200b and 200c of the adjacent cell 2 and cell 3 (the collected transmission power information is transmitted from the transmission power storage unit 121). Read), and the sum for each slot is calculated. For the calculation, a value that corrects the distance between the base station 200a and the base stations 200b and 200c, which are peripheral interference stations, is taken into account. good.
[0081] 図 15に示すダウンリンク送信電力の総和を用い、要求スロットの割当は、総和の一 番小さいスロット 8から割り当てられる。次にスロット 7に要求送信電力が割り当てられ る。最後にスロット 6に要求送信電力が割り当てられる。 3つのスロットの番号と各電力 情報を含む割当情報が基地局 200に通知され、基地局 200で各端末のスロット割当 が行なわれる。基地局 200aでのスロット割当は要求送信電力の大き!/、端末から開始 され、具体的には端末 F、 A、 B、 E、 C、 G、 Dの順になる。スロット割当は各端末の要 求ダウンリンク送信電力を満たすスロットのから選択される。  Using the sum of downlink transmission power shown in FIG. 15, request slots are assigned from slot 8, which is the smallest sum. Next, the requested transmission power is assigned to slot 7. Finally, the requested transmission power is assigned to slot 6. Allocation information including three slot numbers and power information is notified to base station 200, and base station 200 performs slot allocation for each terminal. Slot allocation at the base station 200a starts with the required transmission power! /, Starting from the terminal, and specifically in the order of the terminals F, A, B, E, C, G, D. The slot assignment is selected from the slots that satisfy the required downlink transmission power of each terminal.
[0082] このように、第 1の実施形態のスロット割当によれば、複数のセル力 なる無線通信 システムにおいて、各移動局 300の伝搬路状況から導出される要求送信電力を隣接 するセルの送信電力状況に応じて適応的にスロットに割り当てることにより、隣接する セル力もの干渉波による無線通信品質の低下を抑えることができる。また、干渉電力 値の小さいスロットを使用することによって品質を上げるための過剰な電力の消費を 抑えることができる。  Thus, according to the slot allocation of the first embodiment, in the wireless communication system having a plurality of cell powers, the requested transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells. By assigning slots adaptively according to the power situation, it is possible to suppress degradation of wireless communication quality due to interference waves of adjacent cell power. In addition, by using a slot with a small interference power value, excessive power consumption for improving quality can be suppressed.
[0083] なお、上記のような送信電力割当は必ずしも毎フレーム行なう必要はない。  Note that the transmission power allocation as described above is not necessarily performed every frame.
[0084] また、本実施形態では、閾値より小さい要求送信電力については、基地局 200内 で、未割当のスロットへ要求送信電力を割り当てた。これは、閾値以下の要求送信電 力は、干渉はとして影響が少な 、と 、うことを前提として 、る。 Further, in the present embodiment, for the requested transmission power smaller than the threshold value, the requested transmission power is allocated to an unallocated slot in the base station 200. This is based on the assumption that the requested transmission power below the threshold is less affected by interference.
[0085] さらに、基地局 200が基地局制御局 100へ通知するスロット数と要求送信電力につ いて、一つの移動局 300へ複数のスロットを割り当てたい場合、一つの要求送信電 力へ複数のスロットを割り当てるように、基地局制御局 100へ通知することも可能であ る。 [0085] Furthermore, when it is desired to assign a plurality of slots to one mobile station 300 regarding the number of slots and the requested transmission power that the base station 200 notifies to the base station control station 100, one requested transmission power is required. It is also possible to notify the base station control station 100 to allocate a plurality of slots to the power.
[0086] (第 2の実施形態）  [0086] (Second Embodiment)
次に、本発明に係る無線通信システムの第 2の実施形態について説明する。本実 施形態では、スロットの送信電力割当作業を基地局で行なう点が第 1の実施形態と 異なる。  Next, a second embodiment of the wireless communication system according to the present invention will be described. This embodiment is different from the first embodiment in that the slot transmission power allocation work is performed by the base station.
[0087] 本実施形態は、第 1の実施形態と同様に TDMA通信方式および FDMA通信方式 を使用するものである。本実施形態で使用する TDMA通信方式および FDMA通信 方式の説明に関しては実施形態 1と同様のため省略する。また、本実施形態のシス テム構成も、図 2と同様である。  This embodiment uses the TDMA communication system and the FDMA communication system as in the first embodiment. The description of the TDMA communication system and FDMA communication system used in this embodiment is the same as in Embodiment 1 and is omitted. The system configuration of this embodiment is the same as that shown in FIG.
[0088] 基地局制御局並びに基地局は、第 1の実施形態とは構成要素が異なる。図 19は、 第 2の実施形態の基地局制御局の構成例を示すブロック図である。図 20は、第 2の 実施形態の基地局の構成例を示すブロック図である。図 19の基地局制御局 400の 制御情報処理部 420は、図 3の制御情報処理部 120から割当部 123を除いた構成と なっている。図 20の基地局 500は、移動局制御部 550のスケジューリング部 551へ 割当部 123と同様の機能を追加し、スケジューリング部 551へ隣接セル情報記憶部 5 53を追カ卩した構成となって 、る。  [0088] The base station control station and the base station are different from those in the first embodiment. FIG. 19 is a block diagram illustrating a configuration example of the base station control station of the second embodiment. FIG. 20 is a block diagram illustrating a configuration example of the base station according to the second embodiment. The control information processing unit 420 of the base station control station 400 in FIG. 19 has a configuration obtained by removing the allocation unit 123 from the control information processing unit 120 in FIG. The base station 500 in FIG. 20 has a configuration in which the same function as the allocation unit 123 is added to the scheduling unit 551 of the mobile station control unit 550, and the adjacent cell information storage unit 5 53 is added to the scheduling unit 551. The
[0089] 基地局制御局 400の干渉電力算出部 122は、干渉電力情報の送付を受け付けた 基地局以外のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に 加算することにより、スロット毎の干渉電力値を算出する。基地局 500のスケジユーリ ング部 551は、基地局制御局 400から取得した干渉電力値と移動局 300から受信し た要求送信電力とを用いて、スロット割当を行なう。スロット割当手順は、後述するが、 概ね第 1の実施形態の割当部 123の手順と同様である。また、隣接セル情報記憶部 553は、隣接セルに関する情報を記憶する記憶領域である。本実施形態では、隣接 セル情報として、干渉電力値を記憶する。なお、隣接セル情報記憶部 553は、一時 的に隣接セル情報を記憶する領域であってもよい。たとえば、スロット割当を実施す るときにのみ確保される記憶領域であってもよい。従って、隣接セル情報を記憶する 記憶領域を確保する仕組みが備えられて 、ればよ 、ことになる。 [0090] 移動局に関するブロック機能は第 1の実施形態と同様であるため省略する。 [0089] The interference power calculation unit 122 of the base station control station 400 adds the downlink transmission power of one or more cells adjacent to the cell other than the base station that received the transmission of the interference power information for each slot. The interference power value for each slot is calculated. The scheduling unit 551 of the base station 500 performs slot allocation using the interference power value acquired from the base station control station 400 and the requested transmission power received from the mobile station 300. The slot allocation procedure will be described later, but is generally the same as the procedure of the allocation unit 123 of the first embodiment. Also, the neighboring cell information storage unit 553 is a storage area that stores information related to neighboring cells. In this embodiment, the interference power value is stored as adjacent cell information. Note that the neighboring cell information storage unit 553 may be an area for temporarily storing neighboring cell information. For example, it may be a storage area that is secured only when slot allocation is performed. Therefore, it would be better if a mechanism for securing a storage area for storing neighboring cell information is provided. [0090] Since the block function related to the mobile station is the same as that of the first embodiment, the description thereof is omitted.
[0091] 以下に、第 2の実施形態におけるスロット割当の手順および動作を説明する。図 21 は、第 2の実施形態におけるスロット割当の一例を示すシーケンス図である。第 1の実 施形態のシーケンス図である図 14と比較すると、無線通信フレームの各スロットのス ロット割当および移動局割当を各セル内の各基地局 500が行なうことに違いがある。  [0091] The procedure and operation of slot allocation in the second embodiment will be described below. FIG. 21 is a sequence diagram showing an example of slot allocation in the second embodiment. Compared to FIG. 14, which is a sequence diagram of the first embodiment, there is a difference that each base station 500 in each cell performs slot allocation and mobile station allocation for each slot of the radio communication frame.
[0092] 以下の説明においては第 1の実施形態と同様に図 6から図 9に示したセル配置や セル 1の要求送信電力等の例におけるダウンリンク無線データのスケジューリング例 を説明する。図 9のセル 2およびセル 3に関しては第 1の実施形態と同様に既に本実 験形態 (もしくは第 1の実施の形態）と同様の方法によりチャネル割当が行なわれて いるものとする。セル 2およびセル 3それぞれの移動局 300の要求送信電力の相対 関係は図 10、図 11に示したようになっているものとし、それぞれの割当状況は図 12 、図 13に示したようなチャネル割当状況となっているものとする。  In the following description, as in the first embodiment, scheduling examples of downlink radio data in the examples such as the cell arrangement and the required transmission power of cell 1 shown in FIGS. 6 to 9 will be described. As for cell 2 and cell 3 in FIG. 9, it is assumed that channel assignment has already been performed in the same manner as in the present experiment (or the first embodiment), as in the first embodiment. Assume that the relative transmission power requirements of mobile stations 300 in cell 2 and cell 3 are as shown in Figs. 10 and 11, and the allocation status of each channel is as shown in Figs. 12 and 13. It is assumed that the allocation status has been reached.
[0093] まず、基地局制御局 400は、図 14と同様に各基地局 500から送信電力情報を収 集する (ステップ S50)。セル 1内にある端末 Aから端末 Gにおいて通信要求が発生し スロット割当機会を得た場合には、先ず図 20に示すように、基地局から定期的に送 信される制御信号を移動局 300 (端末 Aから G)のそれぞれが受信を行なう (ステップ S51)。各移動局 300は受信した信号の受信電力レベルを測定し (ステップ S52)、さ らに受信信号を復調すること (ステップ S53)によって、基地局 500から送信された制 御情報 (送信電力情報)を得ることができる (ステップ S54)。制御信号は基地局 500 カゝら一定期間ごとに送信されており、その送信電力は移動局 300がセルエッジ付近 に位置して 、る場合にぉ 、ても受信可能な電力および変調方式に設定されて 、る。 制御スロットにて送信される制御情報には、制御情報を送信した制御スロットの送信 電力、各移動局のスロット割当情報が含まれているものとする。次に復調信号から得 られた送信電力と受信電力レベルから伝搬路における電波の伝搬損を算出する。移 動局は前述した伝搬損を基に要求送信電力と変調方式を導出し (ステップ S55)、そ の結果をアップリンクにて基地局 500に通知を行なう。  First, base station control station 400 collects transmission power information from each base station 500 as in FIG. 14 (step S50). When a communication request is generated from terminal A in terminal 1 to terminal G and a slot allocation opportunity is obtained, first, as shown in FIG. 20, a control signal periodically transmitted from the base station is transmitted to mobile station 300. Each of (terminals A to G) performs reception (step S51). Each mobile station 300 measures the received power level of the received signal (step S52), and further demodulates the received signal (step S53), thereby transmitting control information (transmission power information) transmitted from the base station 500. Can be obtained (step S54). The control signal is transmitted at regular intervals such as 500 base stations, and the transmission power is set to the power and modulation scheme that can be received even when the mobile station 300 is located near the cell edge. And The control information transmitted in the control slot includes transmission power of the control slot that transmitted the control information and slot allocation information of each mobile station. Next, the propagation loss of the radio wave in the propagation path is calculated from the transmission power and reception power level obtained from the demodulated signal. The mobile station derives the required transmission power and modulation scheme based on the above-described propagation loss (step S55), and notifies the base station 500 of the result via the uplink.
[0094] 基地局 500はスロット割当方法において必要な各移動局 300のダウンリンクの要求 送信電力を得る (ステップ S57)。この間、基地局 500は、既に割当済みの端末には データを送信して!/、る（ステップ S56)。 [0094] Base station 500 obtains the downlink required transmission power of each mobile station 300 required in the slot allocation method (step S57). During this time, base station 500 does not Send data! /, (Step S56).
[0095] 基地局 500は、基地局制御局 400から周辺基地局 500のダウンリンク送信電力を 基にした各スロットの干渉電力値を受信し (ステップ S58)、隣接セル情報記憶部 553 へ格納する。干渉電力値は、第 1の実施形態と同様に算出され、干渉局となる隣接 セルの基地局 500が物理的距離または地形的障害などの要因で干渉レベルが最近 接セルの基地局 500より低い基地局 500に関しては予め減衰量に応じた係数を設 定することが望ましい。 [0095] Base station 500 receives the interference power value of each slot based on the downlink transmission power of neighboring base station 500 from base station control station 400 (step S58), and stores it in adjacent cell information storage section 553. . The interference power value is calculated in the same way as in the first embodiment, and the interference level of the base station 500 of the adjacent cell that is the interference station is lower than the base station 500 of the nearest cell due to factors such as physical distance or topographical obstacles. For base station 500, it is desirable to set a coefficient corresponding to the amount of attenuation in advance.
[0096] 次に、基地局 500のスケジューリング部 551は、要求送信電力が最も大きい順に、 スロットの割当を行なう（ステップ S59)。図 22は、基地局 500における移動局 300の 使用するスロットの割当動作の一例を示すフローチャートである。スケジューリング部 551は、要求送信電力が最も大きい順番にスロット割当を行なう。このため、スロットを 割り当てていない移動局 300から最も大きな要求送信電力を要求した移動局を選択 する (ステップ S71)。割当方法は、干渉波となる隣接基地局 500の送信電力の和で ある干渉電力値の最も小さ 、未割当スロットに、選択した要求送信電力を割り当てる (ステップ S72)。最も大きい要求送信電力が必要な移動局からから順に割り当て、次 に大きい要求送信電力である移動局のスロットを前記最も大きい要求送信電力を必 要とする移動局が使用するスロット以外のスロット中で最も干渉電力値の総和が低く なるスロットにそれを割り当てる。その後、以上の作業を割り当てるスロットがなくなるま で続ける (ステップ S73)。  [0096] Next, scheduling section 551 of base station 500 performs slot allocation in order of the highest required transmission power (step S59). FIG. 22 is a flowchart showing an example of an operation of assigning slots used by the mobile station 300 in the base station 500. Scheduling section 551 assigns slots in the order of the largest required transmission power. Therefore, the mobile station that has requested the largest required transmission power is selected from the mobile stations 300 to which no slot is assigned (step S71). The allocation method allocates the selected requested transmission power to the unallocated slot having the smallest interference power value, which is the sum of the transmission powers of adjacent base stations 500 serving as interference waves (step S72). The mobile station that has the highest required transmission power is assigned in order from the mobile station that requires the highest required transmission power, and the slot of the mobile station that has the next highest required transmission power is the slot other than the slot that is used by the mobile station that requires the highest required transmission power Assign it to the slot with the lowest total interference power value. Thereafter, the process is continued until there is no slot to which the above work is assigned (step S73).
[0097] スロット割当結果は、制御スロットによりセル内の移動局へ報知される（ステップ S74 )。その後、割り当てられたデータがダウンリンク送信される (ステップ S75)。  [0097] The slot allocation result is reported to the mobile station in the cell by the control slot (step S74). Thereafter, the allocated data is transmitted in the downlink (step S75).
[0098] また、基地局 500でのダウンリンク送信電力の割当が終了した後、基地局制御局 4 00に送信電力割当情報の通知を行なう。但し、この手順は各移動局 300への制御 情報送信およびデータ送信手順の後でも可能である。  [0098] After the downlink transmission power allocation in base station 500 is completed, transmission power allocation information is notified to base station control station 400. However, this procedure is possible even after the control information transmission and data transmission procedure to each mobile station 300.
[0099] 以上のように行なわれた割当の結果は、ここでは図 18と同様になる。具体的には基 地局にてダウンリンク送信電力の設定およびスロットの割当を行なうのは端末 F、端末 A、端末 B、端末 E、端末 C、端末 G、端末 Dの順になる。この時、基地局制御局 400 は、隣接基地局であるセル 2とセル 3の基地局力 のダウンリンク送信電力の情報を 収集し、スロット毎の総和を干渉電力値として算出する（干渉電力算出部 122が実施 ) o算出した干渉電力値を割当が行なわれる基地局 500に通知する。基地局 500で の割当は、各スロットの干渉電力値が一番小さいスロットに要求送信電力が最も大き Vヽ移動局 300が割り当てられるようになる。 [0099] The result of the assignment performed as described above is the same as in FIG. Specifically, the base station sets downlink transmission power and assigns slots in the order of terminal F, terminal A, terminal B, terminal E, terminal C, terminal G, and terminal D. At this time, the base station control station 400 obtains the downlink transmission power information of the base station power of cell 2 and cell 3 that are adjacent base stations. Collected and calculated the sum of each slot as an interference power value (implemented by interference power calculation unit 122) o Notifies the calculated interference power value to base station 500 to which allocation is performed. Allocation at base station 500 is such that V ヽ mobile station 300 has the largest required transmission power in the slot with the smallest interference power value in each slot.
[0100] なお、第 1の実施形態では、閾値以下の要求送信電力の割当は、基地局 200内で 、送信電力情報 (干渉電力値)を利用することなく実施されるため、閾値以下の要求 送信電力については図 18とは異なる結果となる場合が生じる。ここでは、同様の結 果になる場合を示したに過ぎな 、。  [0100] In the first embodiment, since the allocation of the requested transmission power below the threshold is performed without using the transmission power information (interference power value) in the base station 200, the request transmission below the threshold is requested. The transmission power may be different from that shown in FIG. Here, we have only shown cases where similar results are obtained.
[0101] このように、第 2の実施形態のスロット割当によれば、複数のセル力 なる無線通信 システムにおいて、各移動局 300の伝搬路状況から導出される要求送信電力を隣接 するセルの送信電力状況に応じて適応的にスロットに割り当てることにより、隣接する セル力もの干渉波による無線通信品質の低下を抑えることができ、また、干渉電力値 の小さいスロットを使用することによって品質を上げるための過剰な電力の消費を抑 えることができる。さらに、第 1の実施形態と比較して基地局制御局 400と基地局 500 間でやり取りする情報量が少ないという利点があり、割当に要する時間が短縮するこ とがでさる。  [0101] Thus, according to the slot allocation of the second embodiment, in a wireless communication system having a plurality of cell powers, the required transmission power derived from the propagation path status of each mobile station 300 is transmitted to adjacent cells. By assigning slots adaptively according to the power situation, it is possible to suppress degradation of wireless communication quality due to interference waves from neighboring cells, and to improve quality by using slots with low interference power values. Excessive power consumption can be suppressed. Further, compared with the first embodiment, there is an advantage that the amount of information exchanged between the base station control station 400 and the base station 500 is small, and the time required for allocation can be shortened.
[0102] なお、本実施の形態では、基地局制御局 400は、送信電力情報から算出した干渉 電力値を基地局 500へ通知する場合を説明したが、送信電力情報そのものを基地 局 200へ通知する場合であってもよい。この場合、基地局制御局 400から基地局 20 0へ通知される情報量は増えるものの、基地局制御局 400の処理量自体は減ること になる。また、隣接セル情報記憶部 553は、送信電力情報を記憶することになる。  [0102] In the present embodiment, base station control station 400 has explained the case of notifying base station 500 of the interference power value calculated from the transmission power information, but notifying base station 200 of the transmission power information itself. It may be the case. In this case, although the amount of information notified from the base station control station 400 to the base station 200 increases, the processing amount of the base station control station 400 itself decreases. Also, the neighboring cell information storage unit 553 stores transmission power information.
[0103] さらに、本実施形態の基地局制御局 400は、割当部 123を有する構成であってもよ い。例えば、図 3に示す基地局制御局 100力 基地局 500からの干渉電力値の送付 要求を受け付け、干渉電力値を通知するようにしてもよい。図 3に示す基地局制御局 100が干渉電力値の送付要求を受け付ける機能も保持する場合、基地局として、図 4示す基地局 200と図 20に示す基地局 500とが混在する場合であってもよいことに なる。  [0103] Furthermore, the base station control station 400 of the present embodiment may be configured to include the allocation unit 123. For example, the interference power value transmission request from the base station control station 100 shown in FIG. 3 from the base station 500 may be received and the interference power value notified. When the base station control station 100 shown in FIG. 3 also has a function of accepting an interference power value transmission request, the base station 200 shown in FIG. 4 and the base station 500 shown in FIG. It will be good.
[0104] (第 3の実施形態） 第 3の実施形態では、第 1の実施形態および第 2の実施形態と基本的な割当方法 は同一であるが、通信に使用するフレーム構成が異なる例を説明する。 [0104] (Third embodiment) In the third embodiment, an example in which the basic allocation method is the same as in the first and second embodiments, but the frame configuration used for communication is different will be described.
[0105] 本実施形態のフレーム構成は、 TDMA方式と FDMA方式の両方の特徴を併せ持 つ通信方式であり、一般的にマルチキャリア通信方式で用いられる通信方式である。 TDMA方式と FDMA方式の説明につ ヽては、第 1の実施形態で説明したため省略 する。 [0105] The frame configuration of the present embodiment is a communication method having both features of the TDMA method and the FDMA method, and is a communication method generally used in the multicarrier communication method. The description of the TDMA method and the FDMA method is omitted because it has been described in the first embodiment.
[0106] 図 23は、第 3の実施形態の対象となるマルチキャリア Z (TDMA, FDMA) 2次元 のフレーム構成の一例を示す図である。図 23において縦軸が周波数、横軸が時間 である。図 23において、四角の 1つがデータ伝送に用いる最小単位であり、本実施 形態においてはこれをスロットと称している。スロットの中で、斜線の入った四角が制 御スロット（TO)である。この図の場合、 1フレーム中には、時間方向に 9スロット、周波 数方向に 12スロットあることを意味しており、計 108スロット（内 12スロットは制御スロッ ト）が存在して 、ることを意味して 、る。  FIG. 23 is a diagram illustrating an example of a multi-carrier Z (TDMA, FDMA) two-dimensional frame configuration that is a target of the third embodiment. In Fig. 23, the vertical axis is frequency and the horizontal axis is time. In FIG. 23, one of the squares is the minimum unit used for data transmission, and in the present embodiment this is called a slot. Among the slots, the shaded square is the control slot (TO). In the case of this figure, this means that there are 9 slots in the time direction and 12 slots in the frequency direction in one frame, and there are a total of 108 slots (of which 12 slots are control slots). Means.
[0107] 基地局力 移動局に無線データ通信を行なう場合、基地局は上記フレーム構成の 説明で示した図 23の小さい四角 1つひとつ (スロット）を別々の移動局に割り当てて データを送信することも可能であるし、全てのスロットを 1つの移動局に割り当てて無 線通信をすることも可能である。  [0107] Base station power When performing wireless data communication with a mobile station, the base station allocates each small square (slot) in Fig. 23 shown in the description of the frame configuration above to a different mobile station and transmits data. It is also possible to perform wireless communication by assigning all slots to one mobile station.
[0108] 本実施形態では上記フレーム構成を用いて第 1の実施形態で示した基地局制御 局で送信電力割当を行なう方法か、第 2の実施形態で示した基地局でスロット割当を 行なう方法を利用することによって無線データ通信を行なう。  In the present embodiment, a method for performing transmission power allocation in the base station control station shown in the first embodiment using the frame configuration described above, or a method for performing slot allocation in the base station shown in the second embodiment Wireless data communication is performed by using.
[0109] このように、第 3の実施形態のスロット割当によれば、同一周波数を使用する複数の セル力 なる無線通信システムにおいて、各移動局の伝搬路状況力 導出される要 求送信電力を隣接するセルの送信電力状況に応じて適応的にスロットに割り当てる ことにより、隣接するセルからの干渉波による無線通信品質の低下を抑えることがで き、また、干渉電力値の小さいスロットを使用することによって品質を上げるための過 剰な電力の消費を抑えることができる。  [0109] Thus, according to the slot allocation of the third embodiment, in the radio communication system having a plurality of cell powers using the same frequency, the required transmission power derived from the propagation path condition power of each mobile station is reduced. By allocating to slots adaptively according to the transmission power status of neighboring cells, it is possible to suppress degradation of wireless communication quality due to interference waves from neighboring cells, and use slots with small interference power values. As a result, excessive power consumption for improving quality can be suppressed.
[0110] (第 4の実施形態）  [0110] (Fourth embodiment)
第 4の実施形態では、基地局 200のいずれか一つが、スロット割当の機能を備える 一態様について説明する。例えば、図 2において、基地局 200bにスロット割当の機 能を備え、他の基地局 200a、 200c, 200dがスロット割当の機能を備えていない場 合を一例として説明する。基地局 200a、 200c, 200dは、第 1の実施形態並びに第 2の実施形態で基地局制御局 100、 400とやり取りしていた部分を、基地局 200bと やり取りすることになる。すなわち、基地局 200a、 200c, 200dは、基地局 200bと、 図 14のステップ S 19、ステップ S21、ステップ S23、または、図 21のステップ S58、ス テツプ S60のやり取りをすることになる。スロット割当の機能を有する基地局 200bは、 少なくとも、次の構成要素を有することになる。図 4の基地局 200の構成へ送信電力 情報を記憶する記憶領域となる送信電力記憶部を備える。他の構成要素は同様で ある力 スケジューリング部 251の機能に他の基地局 200からのスロット割当の機能 を追加する必要がある。すなわち、スケジューリング部 251は、他の基地局 200から 要求されるスロット割当を実施する機能を備える必要がある。 In the fourth embodiment, any one of the base stations 200 has a slot allocation function. One aspect will be described. For example, in FIG. 2, a case where the base station 200b has a slot assignment function and the other base stations 200a, 200c, and 200d do not have a slot assignment function will be described as an example. The base stations 200a, 200c, and 200d exchange with the base station 200b the parts that were exchanged with the base station control stations 100 and 400 in the first embodiment and the second embodiment. That is, the base stations 200a, 200c, and 200d communicate with the base station 200b in step S19, step S21, and step S23 in FIG. 14, or step S58 and step S60 in FIG. The base station 200b having the slot assignment function has at least the following components. A transmission power storage unit serving as a storage area for storing transmission power information is added to the configuration of base station 200 in FIG. The other components are the same. The function of slot allocation from another base station 200 needs to be added to the function of the power scheduling unit 251. That is, the scheduling unit 251 needs to have a function of performing slot allocation requested from another base station 200.
[0111] 制御対象である自己のセル内の移動局 300から要求送信電力を受信した場合、ス ケジユーリング部 251は、送信電力情報を用いて、制御対象である自己のセルに隣 接する一つ以上のセルのダウンリンク送信電力をスロット毎に加算することにより、ス ロット毎の干渉電力値を算出し、前記干渉電力値が所定の値と比較して小さいスロッ トへ受信した要求送信電力を割り当てる。  [0111] When the requested transmission power is received from the mobile station 300 in its own cell that is the control target, the scheduling unit 251 uses the transmission power information and one or more adjacent to the own cell that is the control target. By adding the downlink transmission power of each cell for each slot, the interference power value for each slot is calculated, and the received requested transmission power is allocated to a slot where the interference power value is smaller than a predetermined value. .
[0112] また、基地局取得部 220が、他の基地局 200から他の基地局 200が制御する移動 局の要求送信電力を取得した場合、次のようにして他のセルのスロット割当を実施す る。スケジューリング部 251は、送信電力情報を用いて、他のセルに隣接する一つ以 上のセルのダウンリンク送信電力をスロット毎に加算することにより、スロット毎の干渉 電力値を算出し、前記干渉電力値が所定の値と比較して小さ 、スロットへ取得した要 求送信電力を割り当てる割当情報を作成する。作成された割当情報は、基地局通知 部 210によって、他の基地局へ通知される。なお、上記では基地局 200bがスロット割 当の機能を備える場合を説明したが、複数の基地局がスロット割当の機能を備えて いてもよい。さらに、全基地局がスロット割当の機能を備えていてもよい。  [0112] In addition, when the base station acquisition unit 220 acquires the requested transmission power of the mobile station controlled by the other base station 200 from the other base station 200, the slot allocation of other cells is performed as follows. The Using the transmission power information, the scheduling unit 251 calculates the interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to other cells for each slot, and calculates the interference power value. Allocation information for assigning the requested transmission power acquired to the slot is generated when the power value is smaller than the predetermined value. The created allocation information is notified to other base stations by the base station notification unit 210. In addition, although the case where the base station 200b has a slot assignment function has been described above, a plurality of base stations may have a slot assignment function. Further, all base stations may have a slot allocation function.
[0113] このように、本実施の形態では、特定の基地局が送信電力情報を収集する機能と、 干渉電力値を算出する機能と、干渉電力値を用いてスロットを割り当てる機能とを有 する構成を採ることができる。この場合、干渉電力値を用いてスロットを割り当てる機 能を各基地局が備える構成を採ることも可能となり、この場合、第 2の実施形態で説 明した基地局 500 (図 20)を用いることになる。このようにして、隣接セルの干渉を削 減することが可能となる。 [0113] Thus, in this embodiment, a specific base station has a function of collecting transmission power information, a function of calculating an interference power value, and a function of assigning a slot using the interference power value. The structure to do can be taken. In this case, it is possible to adopt a configuration in which each base station has a function of allocating slots using the interference power value. In this case, the base station 500 (FIG. 20) described in the second embodiment is used. become. In this way, it is possible to reduce the interference of neighboring cells.
[0114] 以上のように、上記各実施形態では、複数の移動局は、送信に用いるダウンリンク 送信電力の設定値を基地局制御局若しくは基地局に報告し、基地局制御局もしくは 基地局は、報告されたダウンリンク送信電力の設定値を元に基地局のダウンリンク送 信電力の設定値を決定し、複数の基地局間の干渉量が最小となるような割当を行な う。これにより、隣接セルの送信電力を考慮し、自セルの移動局の干渉電力値がより 小さくなるように基地局制御局または基地局でスロットの送信電力を割り当てることが できる。その結果、各移動局は 1セル繰り返しでありながら隣接する基地局からの干 渉量を最小限に抑えた状態で良好な受信が可能となる。特に、複数の隣接するセル 間で同一周波数を用いる無線通信システムでセル間の干渉を削減することができる [0114] As described above, in each of the above embodiments, the plurality of mobile stations report the setting value of the downlink transmission power used for transmission to the base station control station or the base station, and the base station control station or the base station Then, based on the reported downlink transmission power setting value, the base station downlink transmission power setting value is determined, and allocation is performed so that the amount of interference among a plurality of base stations is minimized. This allows the base station control station or the base station to allocate the slot transmission power so that the interference power value of the mobile station of its own cell becomes smaller in consideration of the transmission power of the adjacent cell. As a result, each mobile station can perform good reception in a state where the amount of interference from adjacent base stations is minimized while repeating one cell. In particular, it is possible to reduce interference between cells in a wireless communication system using the same frequency between a plurality of adjacent cells.
[0115] また、非特許文献 1に記載のように、 3GPPにて規格ィ匕が行われた HSDPA (High [0115] Also, as described in Non-Patent Document 1, HSDPA (High
- Speed Downlink Packet Access)では、基本的に送信電力を一定にし、変 調方式及び誤り訂正の符号化率を動的に選択して、下りの伝搬状態に適応した最大 伝送速度を目指している。この方法においては、基地局からの送信電力が常に一定 となるため、基本的には干渉電力の値は一定として扱うことができる力 一方で基地 局と移動局との距離が近い場合にも一定の送信電力で送信されるため、十分良好な 受信環境にある移動局へは余剰な送信電力を使用して送信することになる。本発明 の好適な実施形態によれば、下りリンクの送信電力を移動局にとって適切な値に制 御することによる効果は前述の基地局の余剰な送信電力の削減だけでなぐ隣接す るセルへの影響を低減するという効果も生じる。すなわち、送信電力を下げることによ つて自セルから隣接するセルへ信号が届きにくくなり、結果として隣接セルにとっての 干渉信号の電力を低くすることが可能になる。  -Speed Downlink Packet Access) basically aims to achieve the maximum transmission rate that adapts to the downlink propagation state by keeping the transmission power constant and dynamically selecting the modulation method and error correction coding rate. In this method, since the transmission power from the base station is always constant, the power of the interference power can basically be treated as constant, while it is constant even when the distance between the base station and the mobile station is short. Therefore, it is transmitted to the mobile station in a sufficiently good reception environment using the excess transmission power. According to the preferred embodiment of the present invention, the effect of controlling the downlink transmission power to an appropriate value for the mobile station is not limited to the above-described reduction of the excessive transmission power of the base station, but to adjacent cells. The effect of reducing the influence of is also produced. That is, by reducing the transmission power, it becomes difficult for a signal to reach an adjacent cell from its own cell, and as a result, the power of an interference signal for the adjacent cell can be reduced.
[0116] また、上記各実施形態では、好適な無線通信システム（無線セルラシステム）の一 態様として、隣接するセルにおいて同一の周波数が用いられる一セル繰り返し方式 が採用され、一つのセルには前記セルを管轄する基地局が配置されると共に、複数 の基地局は制御局によって統括的に制御され、移動局には、少なくともスロットが割り 当てられ、かつ、基地局力 移動局に向力 ダウンリンクに関して送信電力制御がな される無線通信システムに効果的に適用され、制御局、または、この制御局の少なく とも一部の機能を備える基地局は、次の機能を実施する構成要素 (手段)を少なくと も備えることを説明した。（1)隣接する複数のセルの各々を管轄する基地局の各々か ら、各スロットに割り当てられたダウンリンク送信電力情報を収集する機能 (情報収集 手段)、 (2)収集した送信電力情報に基づ！、て、スロット毎の干渉状況を示す情報（ 干渉情報、干渉電力値)を生成する機能 (干渉情報生成手段)、（3)ダウンリンクの通 信が行われる際に、スロット毎の干渉状況を示す情報に基づいて、干渉レベルの低 いスロットを通信先の移動局に、動的 (適応的）に割り当てる機能 (割当手段)。すな わち、無線通信システムの制御局または基地局の 、ずれかある!/、は両方にお!、て、 移動局から通知されるダウンリンク送信電力情報を各セルの基地局を介して収集し（ 情報収集手段)、収集したダウンリンク送信電力情報をスロット毎に加算して和を算出 することにより干渉情報を生成し (干渉情報生成手段）、生成した干渉情報を用いて 、移動局を適応的にスロットへ割り当てる (割当手段)機能を実施する。制御局または 基地局で実施する具体的な機能は、上記実施形態で説明した通りであり、制御局ま たは基地局のどちらで実施しても、無線通信システム全体として上記機能が実施され れば十分であることも、上記各実施形態で示した。また、制御局または基地局が実施 するその他の機能についても、上記各実施形態に示した例に説明されている。 [0116] Also, in each of the above embodiments, as one aspect of a preferred wireless communication system (wireless cellular system), a one-cell repetition method in which the same frequency is used in adjacent cells. A base station that manages the cell is arranged in one cell, a plurality of base stations are centrally controlled by the control station, at least a slot is allocated to the mobile station, and Base station power Direction to mobile station Effectively applied to a radio communication system in which transmission power control is performed on the downlink, a control station or a base station having at least a part of functions of this control station It has been explained that at least the components (means) for implementing the above functions are provided. (1) Function to collect downlink transmission power information allocated to each slot from each base station that manages each of a plurality of adjacent cells (information collecting means), (2) In the collected transmission power information Based! A function for generating information (interference information, interference power value) indicating the interference status for each slot (interference information generating means), and (3) the interference status for each slot when downlink communication is performed. A function (allocation means) that dynamically (adaptively) allocates a slot with a low interference level to a destination mobile station based on the information shown. That is, there is a difference between the control station or base station of the radio communication system! /, And the downlink transmission power information notified from the mobile station is transmitted via the base station of each cell. Collecting (information collecting means), adding the collected downlink transmission power information for each slot and calculating the sum to generate interference information (interference information generating means), and using the generated interference information, the mobile station The function of allocating to the slot adaptively (assignment means) is implemented. The specific functions implemented in the control station or base station are as described in the above embodiment, and the above functions are implemented as a whole wireless communication system regardless of whether the control station or base station implements the functions. It has also been shown in the above embodiments that it is sufficient. Also, other functions performed by the control station or the base station are described in the examples shown in the above embodiments.
なお、上記各実施形態では、スロット割当を行なう場合、セルごとに単独で実施する ことを前提として説明した。これは、基地局制御局および基地局で行なわれる割当は 隣接基地局情報を参照して行なうため、基地局制御下にある各基地局が異なった時 間に再割当作業を行なうことが好ましいことに基づく。特に、隣接する基地局にて同 時に割当を行なう場合には干渉状況が割当後フレームで同時に変化するため、無線 通信品質に影響する可能性がある。このため、複数のセルについて、同時にスロット 割当が実施されるような現象を防ぐことが望ましい。また、基地局制御局および基地 局における送信電力割当時には隣接セル力 の干渉波による劣化を考慮した電力 割当を行なうことが好ま 、。 In each of the above-described embodiments, the description has been made on the assumption that slot allocation is performed independently for each cell. This is because the base station control station and the allocation performed by the base station are performed by referring to the neighboring base station information, and it is preferable that each base station under the control of the base station performs the reassignment work at a different time. based on. In particular, when the allocation is performed simultaneously in adjacent base stations, the interference situation changes simultaneously in the post-allocation frame, which may affect the radio communication quality. For this reason, it is desirable to prevent a phenomenon in which slot allocation is performed simultaneously for a plurality of cells. In addition, when allocating transmission power at the base station control station and the base station, power that takes into account degradation of adjacent cell power due to interference waves I prefer to make an assignment.
[0118] また、上記各実施形態では、移動局が、要求送信電力を意図的に大きくして送信 することによって、ダウンリンク送信電力を大きくすることが可能となる。例えば、緊急 連絡の場合や、災害時の緊急連絡網を構築したい場合、特別に要求送信電力を大 きくすることができる。特に災害時等に用いるような公共性の高い移動局では、緊急 モード等を設け、モードを変更することによって、要求送信電力を大きくする機能を追 加することができる。あるいは、モード変更の替わりに、特別のスィッチを設け、スイツ チを押すことにより、要求送信電力を大きく機能を追加することも可能である。 [0118] Also, in each of the above embodiments, the mobile station can increase the downlink transmission power by intentionally increasing the required transmission power for transmission. For example, the required transmission power can be increased especially in the case of emergency contact or when it is desired to construct an emergency contact network in the event of a disaster. In particular, mobile stations with high publicity, such as those used in disasters, can be provided with an emergency mode, etc., and a function to increase the required transmission power by changing the mode. Alternatively, it is possible to increase the required transmission power and add a function by providing a special switch instead of changing the mode and pressing the switch.
図面の簡単な説明  Brief Description of Drawings
[0119] [図 1]フレーム構成の一例を示す図である。図 1 (a)は、一般的な TDMA方式のフレ ーム構成の一例を示した図である。図 1 (b)は、一般的な FDMA方式のフレーム構 成の一例を示した図である。  FIG. 1 is a diagram showing an example of a frame configuration. Fig. 1 (a) shows an example of a typical TDMA frame structure. Figure 1 (b) shows an example of a general FDMA frame structure.
[図 2]第 1の実施形態の無線通信システムの構成例を示した図である。  FIG. 2 is a diagram illustrating a configuration example of a wireless communication system according to the first embodiment.
[図 3]第 1の実施形態の基地局制御局の構成例を示すブロック図である。  FIG. 3 is a block diagram illustrating a configuration example of a base station control station according to the first embodiment.
[図 4]第 1の実施形態の基地局の構成例を示すブロック図である。  FIG. 4 is a block diagram illustrating a configuration example of a base station according to the first embodiment.
[図 5]第 1の実施形態の移動局の構成例を示すブロック図である。  FIG. 5 is a block diagram illustrating a configuration example of a mobile station according to the first embodiment.
[図 6]セルとセル内に存在する端末配置についての典型的な例を示した図である。  FIG. 6 is a diagram showing a typical example of a cell and a terminal arrangement existing in the cell.
[図 7]セル 1内の各端末 A〜Fに関して要求送信電力の大きさの相対関係を示す図 である。  FIG. 7 is a diagram showing the relative relationship between the required transmission power levels for terminals A to F in cell 1.
[図 8]第 1の実施形態で用いるフレーム構成例を示す図である。  FIG. 8 is a diagram showing a frame configuration example used in the first embodiment.
[図 9]セルと端末配置の関係を示す図である。  FIG. 9 is a diagram showing the relationship between cells and terminal arrangements.
[図 10]セル 2内の各端末 H〜Nに関して要求送信電力の大きさの相対関係を示す図 である。  FIG. 10 is a diagram showing a relative relationship between the magnitudes of requested transmission powers for terminals H to N in cell 2.
[図 11]セル 3内の各端末 0〜Uに関して要求送信電力の大きさの相対関係を示す図 である。  FIG. 11 is a diagram showing a relative relationship between the magnitudes of requested transmission powers for terminals 0 to U in cell 3.
[図 12]セル 2内の各端末 H〜Nのスロット割当状況を示す図である。  FIG. 12 is a diagram showing the slot allocation status of each terminal H to N in cell 2.
[図 13]セル 3内の各端末 0〜Uのスロット割当状況を示す図である。  FIG. 13 is a diagram showing the slot allocation status of terminals 0 to U in cell 3;
[図 14]第 1の実施形態におけるスロット割当の一例を示すシーケンス図である。 O FIG. 14 is a sequence diagram showing an example of slot allocation in the first embodiment. O
[図 15]複数のセルそれぞれのスロット毎の送信電力の和を示す図である。  FIG. 15 is a diagram showing the sum of transmission power for each slot of a plurality of cells.
[図1—  [Figure 1-
〇 16]スロット割当手順の一例を示すフローチャートである。  O 16] Flowchart showing an example of the slot allocation procedure.
〇  Yes
[図 17]基地局が各スロットへ移動局を割り当てる手順の一例を示すフローチャートで ある。  FIG. 17 is a flowchart showing an example of a procedure for a base station to assign a mobile station to each slot.
[図 18]第 1の実施形態のスロット割当の結果の一例を示す図である。  FIG. 18 is a diagram illustrating an example of a slot allocation result according to the first embodiment.
圆 19]第 2の実施形態の基地局制御局の構成例を示すブロック図である。  [19] FIG. 19 is a block diagram illustrating a configuration example of a base station control station according to the second embodiment.
圆 20]第 2の実施形態の基地局の構成例を示すブロック図である  圆 20] is a block diagram showing an example of the configuration of a base station according to the second embodiment
[図 21]第 2の実施形態におけるスロット割当の一例を示すシーケンス図である。  FIG. 21 is a sequence diagram showing an example of slot allocation in the second embodiment.
[図 22]基地局における移動局の使用するスロットの割当動作の一例を示すフローチ ヤートである。  FIG. 22 is a flowchart showing an example of an operation of assigning slots used by mobile stations in a base station.
[図 23]第 3の実施形態の対象となるマルチキャリア Z(TDMA、 FDMA) 2次元のフ レーム構成の一例を示す図である。  FIG. 23 is a diagram showing an example of a multi-carrier Z (TDMA, FDMA) two-dimensional frame configuration that is a target of the third embodiment.
[図 24]隣接するセルにおいて異なる周波数帯域を利用して無線通信を行なう無線通 信方式の周波数割当例を示す図である。  FIG. 24 is a diagram showing a frequency allocation example of a radio communication scheme in which radio communication is performed using different frequency bands in adjacent cells.
符号の説明  Explanation of symbols
400 基地局制御局  400 Base station control station
110 制御局取得部  110 Control station acquisition unit
120、 420 制御情報処理部  120, 420 Control information processing section
121 送信電力記憶部  121 Transmit power storage
122 干渉電力算出部  122 Interference power calculator
123 割当部  123 Allocation
130 制御局通知部  130 Control station notifier
200、 200a〜200d、 500 基地局  200, 200a-200d, 500 base station
210 基地局通知部  210 Base station notification section
220 基地局取得部  220 Base station acquisition unit
230 送信部  230 Transmitter
240 受信部  240 receiver
250、 550 移動局制御部 251、 551 スケジューリング250, 550 Mobile station controller 251 and 551 scheduling
252 電力制御部 252 Power control unit
260 アンテナ部  260 Antenna section
300、 300a〜3001 移動局 300, 300a to 3001 Mobile station
310 受信部 310 Receiver
320 送信部  320 Transmitter
330 情報処理部  330 Information processing department
340 アンテナ部  340 Antenna section
350 受信電力測定部 350 Received power measurement unit
553 隣接セル情報記憶部 553 Adjacent cell information storage

Claims

請求の範囲 The scope of the claims
[1] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、複数のスロット 力 構成されるフレームを用いてセル内の移動局と無線通信する複数の基地局を管 理する制御局であって、  [1] A wireless communication system that uses the same frequency between a plurality of adjacent cells, and a control station that manages a plurality of base stations that wirelessly communicate with mobile stations in a cell using a frame composed of a plurality of slot forces. There,
各スロットに割り当てられたダウンリンク送信電力を複数のセルそれぞれの基地局 力も収集すると共に、移動局とのダウンリンク通信に要求される要求送信電力を特定 のセルの基地局力 取得する制御局取得部と、  Acquire the downlink transmission power allocated to each slot as well as the base station power of each of the multiple cells, and acquire the required transmission power required for downlink communication with the mobile station to obtain the base station power of a specific cell And
前記特定のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に 加算することにより、スロット毎の干渉電力値を算出する干渉電力算出部と、  An interference power calculation unit that calculates an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot;
前記干渉電力値が所定の値と比較して小さいスロットへ前記要求送信電力を割り 当てる割当部と、  An allocating unit that allocates the requested transmission power to a slot whose interference power value is smaller than a predetermined value;
前記要求送信電力をスロットへ割り当てた割当情報を、前記特定のセルの基地局 へ通知する制御局通知部と、を備えることを特徴とする制御局。  A control station, comprising: a control station notifying unit that notifies the base station of the specific cell of allocation information in which the requested transmission power is allocated to a slot.
[2] 前記制御局取得部は、複数の要求送信電力を取得し、  [2] The control station acquisition unit acquires a plurality of request transmission powers,
前記割当部は、複数のスロットのうち干渉電力が小さいスロットを順番に選択し、選 択したスロットへ複数の要求送信電力を大きい順に割り当てることを特徴とする請求 項 1記載の制御局。  2. The control station according to claim 1, wherein the assigning unit sequentially selects slots having the smallest interference power among the plurality of slots, and assigns the plurality of requested transmission powers to the selected slots in descending order.
[3] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、複数のスロット 力 構成されるフレームを用いてセル内の移動局と無線通信する複数の基地局を管 理する制御局であって、  [3] In a wireless communication system that uses the same frequency between multiple adjacent cells, a control station that manages multiple base stations that wirelessly communicate with mobile stations in the cell using frames configured with multiple slots. There,
複数の基地局にお ヽて各スロットに割り当てられたダウンリンク送信電力をセルと対 応づけて記憶する送信電力記憶部と、  A transmission power storage unit that stores downlink transmission power allocated to each slot in association with a cell in a plurality of base stations;
特定のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に加算 することにより、スロット毎の干渉電力値を算出する干渉電力算出部と、  An interference power calculation unit that calculates an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to a specific cell for each slot;
基地局から、前記干渉電力値の送付要求を取得する制御局取得部と、 前記干渉電力算出部が前記送付要求した基地局のセルを前記特定のセルとして 選択して算出した干渉電力値を前記基地局へ通知する制御局通知部と、を備えるこ とを特徴とする制御局。 A control station acquisition unit that acquires a transmission request for the interference power value from a base station, and an interference power value that is calculated by selecting the cell of the base station that the interference power calculation unit has requested to transmit as the specific cell. A control station comprising a control station notification unit that notifies the base station.
[4] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、制御対象であ るセル内の移動局と無線通信する基地局であって、 [4] In a wireless communication system using the same frequency between a plurality of adjacent cells, a base station that wirelessly communicates with a mobile station in a cell to be controlled,
前記移動局がダウンリンク送信電力として要求する要求送信電力を受信する受信 部と、  A receiving unit that receives requested transmission power requested by the mobile station as downlink transmission power;
請求項 1記載の制御局へ、前記要求送信電力を通知する基地局通知部と、 前記制御局力 要求送信電力をスロットへ割り当てた割当情報を取得する基地局 取得部と、  A base station notification unit that notifies the requested transmission power to the control station according to claim 1, a base station acquisition unit that acquires allocation information in which the control station power requested transmission power is allocated to a slot,
前記割当情報を用いて、前記要求送信電力を要求した移動局とスロットとを対応づ けるスケジューリング部と、  A scheduling unit that associates the mobile station that requested the requested transmission power with the slot using the allocation information;
前記要求送信電力を要求した移動局へ、前記要求送信電力を割り当てたスロットを 通知する送信部と、を備えることを特徴とする基地局。  A base station, comprising: a transmitting unit that notifies a mobile station that has requested the requested transmission power of a slot to which the requested transmission power is allocated.
[5] 前記受信部は、複数の要求送信電力を受信し、 [5] The receiving unit receives a plurality of requested transmission powers,
前記スケジューリング部は、受信した複数の要求送信電力のうち、所定の閾値より 大きい要求送信電力を選択し、  The scheduling unit selects a request transmission power that is greater than a predetermined threshold among the plurality of received request transmission powers,
前記基地局通知部は、選択した要求送信電力を通知することを特徴とする請求項 4記載の基地局。  5. The base station according to claim 4, wherein the base station notification unit notifies the selected requested transmission power.
[6] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、複数のスロット 力 構成されるフレームを用いて制御対象であるセル内の移動局と無線通信する基 地局であって、  [6] In a wireless communication system that uses the same frequency between a plurality of adjacent cells, a base station that wirelessly communicates with a mobile station in a cell to be controlled using a frame composed of a plurality of slot forces,
制御対象であるセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット 毎に加算することによりスロット毎に算出された干渉電力値を制御局力 取得する基 地局取得部と、  A base station acquisition unit that acquires the interference power value calculated for each slot by adding the downlink transmission power of one or more cells adjacent to the cell to be controlled for each slot;
前記移動局がダウンリンク送信電力として要求する要求送信電力を受信する受信 部と、  A receiving unit that receives requested transmission power requested by the mobile station as downlink transmission power;
前記取得した干渉電力値が小さ 、スロットへ受信した要求送信電力を割り当てるス ケジユーリング部と、  A scheduling unit that allocates the requested transmission power received to the slot when the acquired interference power value is small;
前記要求送信電力を要求した移動局へ、前記要求送信電力を割り当てたスロットを 通知する送信部と、を備えることを特徴とする基地局。 A base station, comprising: a transmitting unit that notifies a mobile station that has requested the requested transmission power of a slot to which the requested transmission power is allocated.
[7] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、複数のスロット 力も構成されるフレームを用いて制御対象であるセル内の移動局と無線通信すると 共に、他の基地局を管理する基地局であって、 [7] In a wireless communication system that uses the same frequency between a plurality of adjacent cells, wireless communication is performed with a mobile station in a cell to be controlled using a frame that also includes a plurality of slot forces, and other base stations A base station to manage,
他の基地局のセルについて各スロットに割り当てられたダウンリンク送信電力を収 集する基地局取得部と、  A base station acquisition unit that collects downlink transmission power assigned to each slot for cells of other base stations;
前記移動局がダウンリンク送信電力として要求する要求送信電力を受信する受信 部と、  A receiving unit that receives requested transmission power requested by the mobile station as downlink transmission power;
前記制御対象であるセルに隣接する一つ以上のセルのダウンリンク送信電力をス ロット毎に加算することにより、スロット毎の干渉電力値を算出する干渉電力算出部と 前記干渉電力値が小さ 、スロットへ受信した要求送信電力を割り当てるスケジユー リング部と、  An interference power calculation unit that calculates an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the control target cell for each slot; and the interference power value is small; A scheduling unit that allocates the requested transmission power received to the slot;
前記要求送信電力を要求した移動局へ、前記要求送信電力を割り当てたスロットを 通知する送信部と、を備えることを特徴とする基地局。  A base station, comprising: a transmitting unit that notifies a mobile station that has requested the requested transmission power of a slot to which the requested transmission power is allocated.
[8] 前記基地局取得部は、他のセルの移動局が要求する要求送信電力を他の基地局 から取得し、 [8] The base station acquisition unit acquires the requested transmission power requested by the mobile station of another cell from the other base station,
前記干渉電力算出部は、前記他のセルに隣接する一つ以上のセルのダウンリンク 送信電力をスロット毎に加算することにより、スロット毎の干渉電力値を算出し、 前記スケジューリング部は、前記干渉電力値が小さ 、スロットへ取得した要求送信 電力を割り当てる割当情報を作成し、  The interference power calculation unit calculates an interference power value for each slot by adding a downlink transmission power of one or more cells adjacent to the other cell for each slot, and the scheduling unit calculates the interference power. If the power value is small, create allocation information to allocate the requested transmission power acquired to the slot,
前記基地局通知部は、前記他の基地局へ作成した割当情報を通知することを特徴 とする請求項 7記載の基地局。  8. The base station according to claim 7, wherein the base station notification unit notifies the created allocation information to the other base station.
[9] 前記スケジューリング部は、複数のスロットのうち干渉電力値が小さいスロットを順番 に選択し、選択したスロットへ複数の要求送信電力を大きい順に割り当てることを特 徴とする請求項 6から請求項 8のいずれかに記載の基地局。 [9] The scheduling unit according to any one of claims 6 to 6, wherein the scheduling unit sequentially selects slots having a small interference power value among a plurality of slots, and assigns a plurality of requested transmission powers to the selected slots in descending order. 9. The base station according to any one of 8.
[10] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、複数のスロット 力 構成されるフレームを用いてセル内の移動局と無線通信する複数の基地局を管 理する制御局のスロット割当方法であって、 複数のセルそれぞれについて各スロットに割り当てられたダウンリンク送信電力を複 数の基地局力 収集するステップと、 [10] In a wireless communication system that uses the same frequency between a plurality of adjacent cells, a control station that manages a plurality of base stations that wirelessly communicate with mobile stations in the cell using a frame composed of a plurality of slot forces. A slot allocation method, Collecting downlink transmission power allocated to each slot for each of a plurality of cells by a plurality of base station powers;
移動局とのダウンリンク通信に要求される要求送信電力を特定のセルの基地局から 受け付けるステップと、  Receiving requested transmission power required for downlink communication with a mobile station from a base station of a specific cell;
前記特定のセルに隣接する一つ以上のセルのダウンリンク送信電力をスロット毎に 加算することにより、スロット毎の干渉電力値を算出するステップと、  Calculating an interference power value for each slot by adding the downlink transmission power of one or more cells adjacent to the specific cell for each slot;
前記干渉電力値が小さ ヽスロットへ前記要求送信電力を割り当てるステップと、 前記要求送信電力をスロットへ割り当てた割当情報を、前記特定のセルの基地局 へ通知するステップと、を少なくとも含むことを特徴とするスロット割当方法。  Allocating the requested transmission power to a slot having a small interference power value, and notifying allocation information allocating the requested transmission power to the slot to a base station of the specific cell. Slot allocation method.
[11] 複数の隣接するセル間で同一周波数を用いる無線通信システムで、移動局が存在 する複数のセルが隣接し、複数のスロットから構成されるフレームを用いる無線通信 システムのスロット割当方法であって、  [11] A slot assignment method for a radio communication system that uses a frame composed of a plurality of slots in which a plurality of cells in which a mobile station exists are adjacent to each other in a radio communication system that uses the same frequency between a plurality of adjacent cells. And
複数のセルそれぞれの基地局力 各スロットに割り当てられたダウンリンク送信電力 を収集するステップと、  Collecting base station power of each of a plurality of cells and downlink transmission power allocated to each slot;
前記収集したダウンリンク送信電力のうち、特定のセルに隣接する一つ以上のセル のダウンリンク送信電力をスロット毎に加算することにより、干渉電力値を算出するス テツプと、  A step of calculating an interference power value by adding the downlink transmission power of one or more cells adjacent to a specific cell among the collected downlink transmission powers for each slot; and
ダウンリンク送信電力として要求される要求送信電力を前記特定のセルの基地局 力 取得するステップと、  Obtaining a requested transmission power required as a downlink transmission power of the base station of the specific cell;
前記干渉電力値が小さ!ヽスロットへ前記要求送信電力を割り当てるステップと、を 少なくとも含むことを特徴とするスロット割当方法。  Allocating the requested transmission power to a slot with a small interference power value. The slot allocation method comprising:
[12] 前記干渉電力算出部は、減衰量に応じた係数を前記ダウンリンク送信電力へ乗算 し、前記係数を乗算したダウンリンク送信電力をスロット毎に加算することを特徴とす る請求項 1または請求項 3記載の制御局。  [12] The interference power calculation unit may multiply the downlink transmission power by a coefficient corresponding to an attenuation, and add the downlink transmission power multiplied by the coefficient for each slot. Or a control station according to claim 3.
[13] 前記干渉電力算出部は、減衰量に応じた係数を前記ダウンリンク送信電力へ乗算 し、前記係数を乗算したダウンリンク送信電力をスロット毎に加算することを特徴とす る請求項 7記載の基地局。 [13] The interference power calculation unit may multiply the downlink transmission power by a coefficient corresponding to an attenuation, and add the downlink transmission power multiplied by the coefficient for each slot. The listed base station.
[14] 前記干渉電力を算出するステップは、減衰量に応じた係数を前記ダウンリンク送信 電力へ乗算し、前記係数を乗算したダウンリンク送信電力をスロット毎に加算すること を特徴とする請求項 10または請求項 11記載のスロット割り当て方法。 [14] In the step of calculating the interference power, a coefficient corresponding to an attenuation amount is transmitted in the downlink transmission. 12. The slot allocation method according to claim 10 or claim 11, wherein the downlink transmission power multiplied by the power and multiplied by the coefficient is added for each slot.
複数の隣接するセル間で同一周波数を用い、移動局が存在する複数のセルが隣 接し、複数のスロットから構成されるフレームを用いてセル内の移動局と無線通信す る複数の基地局を管理する制御局を備える無線通信システムであって、  A plurality of base stations that use the same frequency between a plurality of adjacent cells, a plurality of cells in which a mobile station exists, are adjacent to each other, and use a frame composed of a plurality of slots to perform radio communication with the mobile stations in the cell. A wireless communication system comprising a control station for management,
前記基地局または前記制御局の!、ずれかよって、  Depending on the deviation of the base station or the control station,
複数のセルそれぞれの基地局力 各スロットに割り当てられたダウンリンク送信電力 を収集し、  Base station power of each of multiple cells Collects downlink transmission power allocated to each slot,
前記収集したダウンリンク送信電力のうち、特定のセルに隣接する一つ以上のセル のダウンリンク送信電力に基づ 、てスロット毎の干渉電力値を算出し、  Based on the downlink transmission power of one or more cells adjacent to a specific cell out of the collected downlink transmission power, an interference power value for each slot is calculated,
ダウンリンク送信電力として要求される要求送信電力を前記特定のセルの基地局 から取得し、  Obtaining the requested transmission power required as the downlink transmission power from the base station of the specific cell;
前記干渉電力値が小さいスロットへ前記要求送信電力を割り当てることを特徴とす る無線通信システム。  A wireless communication system, wherein the requested transmission power is allocated to a slot having a small interference power value.
PCT/JP2006/313557 2005-07-07 2006-07-07 Control station, base station, slot allocating method, and wireless communication system WO2007007662A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007524622A JP4740241B2 (en) 2005-07-07 2006-07-07 Control station, base station, slot allocation method, and radio communication system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2005199474 2005-07-07
JP2005-199474 2005-07-07

Publications (1)

Publication Number Publication Date
WO2007007662A1 true WO2007007662A1 (en) 2007-01-18

Family

ID=37637055

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/313557 WO2007007662A1 (en) 2005-07-07 2006-07-07 Control station, base station, slot allocating method, and wireless communication system

Country Status (2)

Country Link
JP (1) JP4740241B2 (en)
WO (1) WO2007007662A1 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008117416A1 (en) * 2007-03-27 2008-10-02 Fujitsu Limited Base station, scheduling method, and wireless terminal
JP2010541335A (en) * 2007-09-21 2010-12-24 クゥアルコム・インコーポレイテッド Interference management using power and attenuation profiles
WO2011132760A1 (en) * 2010-04-19 2011-10-27 日本電気株式会社 Database, data structure, secondary usability determination system, and secondary usability determination method
WO2012160932A1 (en) * 2011-05-20 2012-11-29 日本電気株式会社 Transmission device and processing method thereof
US8824979B2 (en) 2007-09-21 2014-09-02 Qualcomm Incorporated Interference management employing fractional frequency reuse
US8837305B2 (en) 2007-11-27 2014-09-16 Qualcomm Incorporated Interference management in a wireless communication system using beam and null steering
US8948095B2 (en) 2007-11-27 2015-02-03 Qualcomm Incorporated Interference management in a wireless communication system using frequency selective transmission
US9066306B2 (en) 2007-09-21 2015-06-23 Qualcomm Incorporated Interference management utilizing power control
US9065584B2 (en) 2010-09-29 2015-06-23 Qualcomm Incorporated Method and apparatus for adjusting rise-over-thermal threshold
US9078269B2 (en) 2007-09-21 2015-07-07 Qualcomm Incorporated Interference management utilizing HARQ interlaces
US9137806B2 (en) 2007-09-21 2015-09-15 Qualcomm Incorporated Interference management employing fractional time reuse
JP2018500798A (en) * 2014-10-31 2018-01-11 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． Method, apparatus, control apparatus and base station for handling inter-cell interference

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07245784A (en) * 1994-03-04 1995-09-19 Nippon Telegr & Teleph Corp <Ntt> Radio base station transmission power controller and controlling method
JP2001358651A (en) * 2000-06-16 2001-12-26 Yrp Mobile Telecommunications Key Tech Res Lab Co Ltd Mobile communication system, base station unit and transmission power control method
JP2002159046A (en) * 2000-11-21 2002-05-31 Nec Corp Time scheduling system
JP2004527969A (en) * 2001-05-14 2004-09-09 インターディジタル テクノロジー コーポレイション Channel allocation in a hybrid TDMA / CDMA communication system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07245784A (en) * 1994-03-04 1995-09-19 Nippon Telegr & Teleph Corp <Ntt> Radio base station transmission power controller and controlling method
JP2001358651A (en) * 2000-06-16 2001-12-26 Yrp Mobile Telecommunications Key Tech Res Lab Co Ltd Mobile communication system, base station unit and transmission power control method
JP2002159046A (en) * 2000-11-21 2002-05-31 Nec Corp Time scheduling system
JP2004527969A (en) * 2001-05-14 2004-09-09 インターディジタル テクノロジー コーポレイション Channel allocation in a hybrid TDMA / CDMA communication system

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008117416A1 (en) * 2007-03-27 2008-10-02 Fujitsu Limited Base station, scheduling method, and wireless terminal
JPWO2008117416A1 (en) * 2007-03-27 2010-07-08 富士通株式会社 Base station, scheduling method, and wireless terminal
US9066306B2 (en) 2007-09-21 2015-06-23 Qualcomm Incorporated Interference management utilizing power control
JP2010541335A (en) * 2007-09-21 2010-12-24 クゥアルコム・インコーポレイテッド Interference management using power and attenuation profiles
US9374791B2 (en) 2007-09-21 2016-06-21 Qualcomm Incorporated Interference management utilizing power and attenuation profiles
US8824979B2 (en) 2007-09-21 2014-09-02 Qualcomm Incorporated Interference management employing fractional frequency reuse
US9344973B2 (en) 2007-09-21 2016-05-17 Qualcomm Incorporated Interference management utilizing power and attenuation profiles
US9137806B2 (en) 2007-09-21 2015-09-15 Qualcomm Incorporated Interference management employing fractional time reuse
US9078269B2 (en) 2007-09-21 2015-07-07 Qualcomm Incorporated Interference management utilizing HARQ interlaces
US9119217B2 (en) 2007-11-27 2015-08-25 Qualcomm Incorporated Interference management in a wireless communication system using frequency selective transmission
US8948095B2 (en) 2007-11-27 2015-02-03 Qualcomm Incorporated Interference management in a wireless communication system using frequency selective transmission
US9072102B2 (en) 2007-11-27 2015-06-30 Qualcomm Incorporated Interference management in a wireless communication system using adaptive path loss adjustment
US8867456B2 (en) 2007-11-27 2014-10-21 Qualcomm Incorporated Interface management in wireless communication system using hybrid time reuse
US8848619B2 (en) 2007-11-27 2014-09-30 Qualcomm Incorporated Interface management in a wireless communication system using subframe time reuse
US9288814B2 (en) 2007-11-27 2016-03-15 Qualcomm Incorporated Interface management in wireless communication system using hybrid time reuse
US8837305B2 (en) 2007-11-27 2014-09-16 Qualcomm Incorporated Interference management in a wireless communication system using beam and null steering
WO2011132760A1 (en) * 2010-04-19 2011-10-27 日本電気株式会社 Database, data structure, secondary usability determination system, and secondary usability determination method
US9065584B2 (en) 2010-09-29 2015-06-23 Qualcomm Incorporated Method and apparatus for adjusting rise-over-thermal threshold
US9106331B2 (en) 2011-05-20 2015-08-11 Nec Corporation Transmission apparatus and processing method thereof
WO2012160932A1 (en) * 2011-05-20 2012-11-29 日本電気株式会社 Transmission device and processing method thereof
JP2018500798A (en) * 2014-10-31 2018-01-11 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． Method, apparatus, control apparatus and base station for handling inter-cell interference
US10298368B2 (en) 2014-10-31 2019-05-21 Huawei Technologies Co., Ltd. Method and device for handling inter-cell interference, control apparatus, and base station

Also Published As

Publication number Publication date
JP4740241B2 (en) 2011-08-03
JPWO2007007662A1 (en) 2009-01-29

Similar Documents

Publication Publication Date Title
JP4740241B2 (en) Control station, base station, slot allocation method, and radio communication system
DK1997334T3 (en) Measuring supported dynamic frequency re-use in mobile telecommunications networks
KR101629519B1 (en) Method and apparatus for scheduling resource allocation to contorl inter-cell interference in a cellular communication system
JP5819086B2 (en) Apparatus and method for controlling transmission of communication system
JP5169689B2 (en) Communication device
JP4885971B2 (en) Base station equipment
US20090143070A1 (en) Supporting an Allocation of Radio Resources
KR100924961B1 (en) Apparatus and Method for Controlling of Downlink Power in Wireless Communication System
EP2351448B1 (en) Fractional frequency reuse in ofdma
EP2445276A2 (en) Method for cooperative control of power among base stations and base station device using same
US20080225752A1 (en) Communication Resource Allocation Method of Base Station
CN101401475A (en) Predetermined transmission mode sequence and feedback reduction technique
US20140119333A1 (en) Methods and arrangements for handling a scheduling of a narrowband transmission in a cellular network
KR101082255B1 (en) Method for transmitting data and cellular system using the same
JP4664261B2 (en) Method, transmitter, receiver and system for dynamic subchannel allocation
KR101306372B1 (en) Dynamic power allocation method and apparatus for controlling inter-cell interference in multi-cell orthogonal frequency division multiplexing access system
KR20150025871A (en) Method and apparatus for resource allocation
JP2002218526A (en) Wireless channel assignment method, wireless base station unit and mobile station unit
WO2016181588A1 (en) Wireless communication device and transmission-power setting method
WO2016181587A1 (en) Wireless communication device and frequency allocation method
JP2010507284A (en) Method and apparatus for determining, communicating and using information that can be used for interference control purposes
Cho et al. Maximum achievement rate allocation algorithm for downlink multi-user OFDMA systems
Abderrazak et al. Fair scheduling and dynamic ICIC for multi-cellular OFDMA systems
KR20180078538A (en) Method, apparatus and system for transmitting svc video data in radio communication environment
JP2010011174A (en) Radio communication method, radio communication system, and radio communication device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2007524622

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06767967

Country of ref document: EP

Kind code of ref document: A1