JP2010263414A - Wireless communication system, wireless device, and wireless communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication system that allows a plurality of wireless stations to execute communication by utilizing the same frequency channel and achieves improvement in frequency utilization efficiency. <P>SOLUTION: The wireless communication system includes a plurality of wireless stations. Each wireless station includes an interference estimating means, and a transmitting means. The interference estimating means estimates the presence of a wireless station that becomes an interference station with respect to one's own station. When the wireless station that becomes the interference station is present, the transmitting means adjusts at least one transmission resource after selecting the at least one transmission resource from among a first transmission resource comprising a transmission beam as an element, a second transmission resource comprising transmission power as an element, a third transmission resource comprising transmission timing as an element, and a fourth transmission resource comprising a transmission frequency as an element. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless communication system, a wireless device, and a wireless communication method including a plurality of wireless stations.

  There is a wireless LAN as a representative system in which a plurality of wireless communication systems use the same frequency channel. In wireless LAN (Local Area Network), interference power can improve communication quality by checking for wireless stations communicating at the same frequency, using a carrier sense function, or performing communication using different frequency bands. Control is performed so as not to cause significant deterioration (Non-Patent Document 1).

“802.11 High-Speed Wireless LAN Textbook”, Impress R & D Publishing, April 2008, p87-107

  However, in a system in which a plurality of wireless communication systems such as the wireless LAN described above use the same frequency channel, the number of wireless stations and the number of wireless stations that increase the communication speed by increasing the frequency band to be used increase. The LAN technology has a problem that the communication speed is restricted by the influence of interference. That is, there are problems that a plurality of radio stations can communicate using the same frequency channel and it is difficult to improve the frequency utilization efficiency.

  By the way, in a wireless communication system such as a wireless LAN, it is known to perform carrier sense so that mutual terminals do not interfere with each other. In a method in which a plurality of wireless communication systems can use the same frequency by performing carrier sense, there is a problem that as the number of wireless stations increases, communication opportunities decrease and throughput decreases. On the other hand, when carrier sense is not performed and communication opportunities are not reduced, signals of a plurality of radio communication systems cause interference with each other, and there is a problem that communication quality is significantly degraded.

  As for interference avoidance, there are a method of avoiding interference on the transmitting station side and a method of avoiding interference on the receiving station side. However, avoiding interference on the receiving station side has a problem of increasing the hardware scale of the receiving station. Also, in a system that feeds back successful reception information to the transmitting station when a packet is correctly received, information on successful reception is transmitted within a predetermined time if the processing delay until interference avoidance increases. It becomes impossible to feed back to the station. Therefore, it is desirable to realize an interference avoidance function on the transmission station side.

  Note that interference avoidance at the transmitting station is aimed at avoiding interference with the communication partner, so the communication quality of the local station does not improve, but rather the characteristics deteriorate. There was a problem that it was difficult to introduce interference avoidance on the side.

  The present invention has been made in view of such circumstances, and a wireless communication system capable of improving the frequency utilization efficiency while allowing a plurality of wireless stations to communicate using the same frequency channel. An object of the present invention is to provide a wireless device and a wireless communication method.

  The present invention has been made to solve the above-described problems, and the invention according to claim 1 is a wireless communication system including a plurality of wireless stations, and the wireless station An interference estimation means for estimating the presence of a radio station serving as an interference station; a first transmission resource including a transmission beam as an element; and a second transmission power as an element when a radio station serving as an interference station exists. And a transmission unit that selects and adjusts at least one of the transmission resource, the third transmission resource having transmission timing as an element, and the fourth transmission resource having transmission frequency as an element. Is a wireless communication system.

  According to a second aspect of the present invention, the transmission means of the wireless station notifies the interference station of the transmission resource selected by the own station, and the interference station responds to the transmission resource being notified from the wireless station. Then, one of the transmission resources of the local station is selected, the selected transmission resource is notified to the radio station, and the selected transmission resource is adjusted. It is a radio | wireless communications system as described in above.

  The invention according to claim 3 is provided with a base station comprising a notification unit that notifies a radio station in which interference has occurred to a transmission resource that avoids interference, and the radio station transmits the transmission resource notified from the base station The wireless communication system according to claim 1, wherein the wireless communication system is adjusted.

  According to a fourth aspect of the present invention, the wireless station transmits a first codebook describing the first resource, a second codebook describing the second resource, and the third resource. A third codebook described above and a storage unit storing at least one of the fourth codebooks describing the fourth resource, and serving as an interfering station for the own station When a radio station exists, one of the first to fourth codebooks is selected, and the selected codebook is notified to the interfering station and recorded in the selected codebook. The wireless communication system according to claim 1, wherein the adjusted resource is adjusted.

  The invention according to claim 5 includes an antenna unit that transmits and receives signals, a signal switching unit that switches transmission and reception of the antenna unit, a signal acquisition unit that acquires a signal received by the antenna unit, and a signal acquisition unit By analyzing the output signal, an interference station information estimation unit that detects an interference station and estimates an interference state of the interference station, and information indicating the interference state of the interference station estimated by the interference station information estimation unit Including an interference station information generation unit that generates an interference station notification signal including, and a transmission unit that transmits a transmission signal including the interference station notification signal via the antenna unit, wherein the transmission unit transmits a transmission beam A first transmission resource having an element, a second transmission resource having a transmission power as an element, a third transmission resource having a transmission timing as an element, and a fourth transmission resource having a transmission frequency as an element Small A radio apparatus, characterized in that by selecting Kutomo one transmission resource is adjustable.

  The invention according to claim 6 includes an antenna unit that transmits and receives signals, a signal switching unit that switches transmission and reception of the antenna unit, a signal acquisition unit that acquires a signal received by the antenna unit, and a signal acquisition unit An interference station information estimation unit that detects an interference station by analyzing an output signal and estimates an interference state of the interference station, and an interference station that includes information on the detected interference station from the output signal of the signal acquisition unit An interference station notification detection unit that detects a notification signal, an interference station negotiation determination unit that determines whether the interference state and the interference station notification signal are interference stations, and the interference station negotiation determination unit When it is determined that they are interfering stations, a first transmission resource whose element is a transmission beam, a second transmission resource whose element is transmission power, and a third element whose element is transmission timing Interference station information generation for generating a negotiation condition signal for selecting at least one transmission resource possessed by the own station from a transmission resource and a fourth transmission resource having a transmission frequency as an element, and adjusting the selected transmission resource And a transmission unit that transmits the transmission signal including the negotiation condition signal via the antenna unit and adjusts the selected transmission resource.

  The invention according to claim 7 is a wireless communication method used in a wireless communication system composed of a plurality of wireless stations, wherein the interference estimation means included in the wireless station is an interference station serving as an interference station for the own station. When a transmission means included in the wireless station executes a procedure for estimating the presence of a station and there is a wireless station serving as an interference station, a first transmission resource including a transmission beam as an element, and a transmission power as an element A procedure for selecting and adjusting at least one of the second transmission resource to be transmitted, the third transmission resource having the transmission timing as an element, and the fourth transmission resource having the transmission frequency as an element. A wireless communication method characterized by the above.

  According to the present invention, radio stations causing interference with each other include a transmission resource that adjusts the direction of the transmission beam, a transmission resource that adjusts transmission power, a transmission resource that switches non-transmission time, and a transmission resource that switches frequency. Interference is avoided by adjusting the transmission resource selected from among them. As a result, interference can be avoided in the entire communication system without reducing the throughput, so that a plurality of radio stations can communicate using the same frequency channel, and the frequency utilization efficiency can be improved. Can be improved.

It is explanatory drawing of the radio | wireless communications system of the 1st-6th and 9th-10th embodiment of this invention. It is a block diagram of an example of the radio | wireless apparatus in the radio | wireless communications system to which this invention was applied. It is a block diagram of the other example of the radio | wireless apparatus in the radio | wireless communications system to which this invention was applied. It is a flowchart used for operation | movement description of the radio | wireless communications system to which this invention was applied. It is explanatory drawing of the radio | wireless communications system of the 7th Embodiment of this invention. It is explanatory drawing of the radio | wireless communications system of the 8th Embodiment of this invention. It is a flowchart used for description of the radio | wireless communications system of the 8th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 shows a state of a wireless communication system according to the first embodiment of the present invention. In FIG. 1, the communication cell 1 includes a base station 110 and terminal stations 111 to 113. The communication cell 2 includes a base station 120 and terminal stations 121 to 123. The communication cell 3 includes a base station 130 and terminal stations 131 to 133.

  In such a wireless communication system, data communication is performed between a base station belonging to each communication cell and a terminal station belonging to the communication cell. That is, the base station 110 belonging to the communication cell 1 performs data communication with the terminal stations 111 to 113 belonging to the communication cell 1. The base station 120 belonging to the communication cell 2 performs data communication with the terminal stations 121 to 123 belonging to the communication cell 2. The base station 130 belonging to the communication cell 3 performs data communication with the terminal stations 131 to 133 belonging to the communication cell 3.

Here, any communication cell is K (K is an arbitrary positive integer), the number of base stations belonging to the communication cells K and N _K, the base station 1K0 belonging to the communication cell K is, 1 to N _K th , 1KL,..., 1KN _K (1 ≦ L ≦ N _K ).

  Thus, the base station belonging to each communication cell performs data communication with the terminal station belonging to the communication cell. However, in a terminal station near an adjacent communication cell, radio waves may reach the base station or terminal station of the adjacent communication cell, causing interference. For example, the terminal station 121 belongs to the communication cell 2 and performs data communication with the base station 120. However, since the terminal station 121 is close to the base station 110 of the adjacent communication cell 1, the base station 110 And the terminal station 121 may cause interference.

Therefore, in the first embodiment of the present invention, the base station 1K0 and the terminal station 1KL estimate interference information for the base station 1J0 and the terminal station 1JM (J ≠ K, 1 ≦ M ≦ N _J ) serving as interference stations. When the presence of an interference station is detected, the radio station or the radio station with which the radio station communicates is notified that the radio station is an interference station. Each terminal station or each base station negotiates transmission conditions and adjusts a transmission resource selected from a plurality of transmission resources, thereby preventing interference.

In a general wireless communication system, the base station 1K0 estimates propagation channel information with the terminal station 1KL (1 ≦ L ≦ N _K ), and the base station 1K0 exchanges data also with the terminal station 1KL. Only the propagation channel information between the two is estimated and used for data decoding. However, communication is not performed with the base station 1J0 and the terminal station 1JM (J ≠ K, 1 ≦ M ≦ N _J ) that does not exchange data but exists in a communicable area and is not connected as data communication (non-N _J ). Patent Document 1).

  Here, the transmission resource is an element that determines a transmission method such as a direction of a transmission beam, transmission power, transmission timing, transmission frequency, and the like. The transmission condition is determined based on the combination of the transmission resources described above, and indicates a transmission state or a transmission method in the radio station. Negotiation refers to transmitting or receiving a signal in order to adjust the above-described transmission resources with a radio station in which interference occurs when interference occurs. Specifically, the negotiation is performed by transmitting a negotiation condition signal described later to the wireless station.

  That is, as shown in FIG. 1, when the base station 110 and the terminal station 121 are interfering stations, the base station 110 first transmits from the terminal station 121 belonging to another communication cell based on the received signal. It is detected that the received signal is received as an interference signal, and the interference state with the terminal station 121 is estimated.

  Here, the interference state can be estimated from the propagation channel information. The propagation channel information is information on a change in phase and power received by a signal before the radio wave arrives at the base station 110 from the terminal station 121. The propagation channel information does not need to be accurately estimated, and the base station 110 divides the propagation channel information into a finite number of groups, and results of determining which group the propagation information between the terminal station 121 belongs to But you can. Further, by notifying under what transmission conditions the terminal station 121 is communicating, it corresponds to the transmission condition used by the terminal station 121 and the transmission condition of the terminal station 121 with high interference Can also be estimated. The base station 110 notifies the terminal station 121 that it is its own interference station. At this time, at least a part of the interference information with the terminal station 121 can be notified to the terminal station 121.

  The terminal station 121 also detects from the received signal that the base station 110 is an interference station, estimates information similar to the propagation channel information in the same manner as the base station 110, and becomes an interference station with the base station 110. Notify that Here, at least part of the interference information with the base station 110 can be notified to the terminal station 110.

  As described above, the base station 110 receives the interference station notification signal from the terminal station 121, so that the terminal station 121 is notified that the own station (base station 110) is an interference station. In addition, the base station 110 has already detected that the terminal station 121 is an interference station. As a result, the base station 110 confirms that the terminal stations 121 are interfering stations.

  When the base station 110 confirms that the terminal stations 121 are interfering stations, the base station 110 negotiates. Then, by selecting a transmission resource from among a plurality of transmission resources and adjusting the transmission resource, interference is prevented.

  As described above, transmission resources include transmission resources whose elements are transmission beams, transmission resources whose elements are transmission power, transmission resources whose elements are transmission timing, and transmission resources whose elements are transmission frequencies.

  More specifically, the transmission conditions include the magnitude of interference power, the amount and ratio of throughput reduction, the type of application in communication, the priority order of terminal stations, and the like.

  As an example of negotiation, instead of the base station 110 not performing directivity control in the direction of the terminal station 121 due to the transmission resource limitation of the transmission beam, the terminal station 121 interferes with the base station 110 due to the transmission resource limitation of the transmission frequency. Interference is reduced by communicating without using a specific frequency band that causes

  FIG. 2 shows an example of a radio apparatus that constitutes the terminal station 121 described above, and FIG. 3 shows an example of a radio apparatus that constitutes the base station 110 described above. First, an example of a wireless device configuring the terminal station 121 will be described with reference to FIG.

  In FIG. 2, the radio apparatus configuring the terminal station 121 includes a plurality of (here, Na) antennas 201-1 to 201-Na, a signal switching unit 202, a signal acquisition unit 203, and an interference station information estimation unit 204. And an interference station information generation unit 205 and a transmission unit 206.

  The Na antennas 201-1 to 201-Na transmit and receive radio waves. The signal switching unit 202 performs transmission / reception switching. At the time of reception, the received signal via the Na antennas 201-1 to 201-Na is sent to the signal acquisition unit 203 via the signal switching unit 202. The signal acquisition unit 203 converts the received signal from an analog signal to a digital signal.

  The interference station information estimation unit 204 analyzes the digital reception signal output from the signal acquisition unit 203, estimates the radio station that is the interference source, and determines the propagation channel information with the interference station or the transmission conditions. Estimate interference information.

  The interference station information generation unit 205 generates an interference station notification signal using at least a part of the interference station or interference information corresponding to the interference station, and outputs the interference station notification signal to the transmission unit 206.

  The transmission unit 206 transmits an interference station notification signal from at least one of the antennas 201-1 to 201-Na via the signal switching unit 202. Note that the transmission unit 206 can select and adjust at least one transmission resource from among a plurality of transmission resources such as a transmission beam, transmission power, transmission timing, and transmission frequency.

  Next, an example of a radio apparatus configuring the base station 110 will be described with reference to FIG. In FIG. 3, the radio apparatuses constituting the base station 110 include antennas 301-1 to 301-Na, a signal switching unit 302, a signal acquisition unit 303, an interference station information estimation unit 304, and an interference station notification detection unit 305. And an interference station negotiation determination unit 306, an interference station information generation unit 307, and a transmission unit 308.

  The Na antennas 301-1 to 301 -Na perform transmission and reception of radio waves. The signal switching unit 302 performs transmission / reception switching. At the time of reception, the received signals via the Na antennas 301-1 to 301-Na are sent to the signal acquisition unit 303 via the signal switching unit 302. The signal acquisition unit 303 converts the received signal from an analog signal to a digital signal.

  The interference station information estimation unit 304 analyzes the digital reception signal output from the signal acquisition unit 203, estimates the radio station that is the interference source, and determines the propagation channel information or transmission conditions between the interference station and the interference station. Estimate interference information.

  The interference station notification detection unit 305 detects the received interference station notification signal from the output signal of the signal acquisition unit 203 and acquires interference station information.

  If the interference station that transmitted the interference station notification signal is a wireless station belonging to the own radio station or the own communication cell, the interference station negotiation determination unit 306 classifies the interference station designated by the interference station notification signal into an interference station group. And associated with the corresponding communication cell or radio station. If the interfering station is a radio station belonging to another communication cell and the interfering station specified by the interfering station notification signal is that of the own radio station or the radio station belonging to the own communication cell, Classify into interference groups and associate with corresponding communication cells or radio stations.

  The interference station information generation unit 307 determines whether or not they are interference stations from the interference station estimated by the interference station information estimation unit 304 and the interference station information obtained from the received interference station notification signal. If they are interfering stations, it is determined that negotiation is possible, and a negotiation condition signal is generated. That is, if both the interfered group and the interference group are registered in the same communication cell or radio station, it is determined that negotiation is possible, and the negotiated station to be negotiated or the radio station of the communication cell including the interfered station is negotiated. A negotiation condition signal for notifying the negotiation content is generated. This negotiation condition signal is for reducing interference by selecting and adjusting at least one transmission resource among a plurality of transmission resources.

  The transmission unit 308 transmits a signal including the negotiation condition signal, and performs transmission from at least one of the antennas 301-1 to 301-Na via the signal switching unit 302. Note that the transmission unit 308 can select and adjust at least one transmission resource from among a plurality of transmission resources such as a transmission beam, transmission power, transmission timing, and transmission frequency.

  As described above, in the first embodiment of the present invention, the base station 110 detects a terminal station 121 belonging to another communication cell as an interference station, and the terminal station 121 detects that the base station 110 is an interference station. And the base station 110 receives the notification (interference station notification signal) from the terminal station 121 and confirms that they are interfering stations with each other, negotiates (transmits a negotiation condition signal), The interference is reduced by adjusting the transmission resources of each other.

  Such processing is realized by the following operation when the wireless device shown in FIG. 2 is used as the terminal station 121 and the wireless device shown in FIG. 3 is used as the base station 110.

  First, the interference station information estimation unit 304 of the radio apparatus of the base station 110 shown in FIG. 3 analyzes the received signal and estimates the signal from the terminal station 121 as an interference signal.

  Also, the interference station information estimation unit 204 of the wireless device that implements the terminal station 121 shown in FIG. 2 analyzes the received signal and estimates the signal from the base station 110 as an interference signal. Then, the interference station information generation unit 205 generates an interference station notification signal indicating that the base station 110 is an interference station, and outputs it from the transmission unit 206.

  The interference station notification detection unit 305 of the base station 110 shown in FIG. 3 receives the interference station notification signal from the terminal station 121, and from the interference station notification signal and the detection output of the interference station information estimation unit 304, Make sure that Then, the interference station information generation unit 307 generates a negotiation condition signal for notifying the contents of the negotiation to the interfered station to be negotiated or the radio station of the communication cell including the interfered station, and transmits the negotiation condition signal from the transmission unit 308. Then, by negotiation, a transmission resource is selected from a plurality of transmission resources, and the selected transmission resource is adjusted, thereby reducing interference as a whole system.

  FIG. 4 is a flowchart for explaining the operation of the radio communication system according to the first embodiment of the present invention. In FIG. 4, when communication is started (step F01), the interference station information estimation units 204 and 304 of the wireless device in FIGS. 2 and 3 determine whether or not there is a wireless station that becomes an interference station (step F02). ). When there are no wireless stations that are interfering stations, normal communication is started (step F08). When there are radio stations that become interference stations with each other, negotiation is performed based on a negotiation condition signal from the interference station information generation unit 307, and transmission units 206 and 308 perform transmission that avoids interference among a plurality of transmission resources. A resource is selected (step F03).

  When interference is avoided by directing transmission beams toward each other as transmission resources (step F04), the transmission beams are set so as not to cause interference, and transmission beam communication is started (step F08). When interference is avoided by reducing transmission power as transmission resources (step F05), transmission power is reduced and communication is started (step F09). When transmission timings are switched as transmission resources to avoid interference (step F06), the time is switched so that interference does not occur, and communication is started (step F10). When transmission frequencies are switched as transmission resources to avoid interference (step F07), the band is switched so that interference does not occur, and communication is started (step F11).

  As described above, in the first embodiment of the present invention, the transmission resource for performing negotiation and adjusting the direction of the transmission beam, the transmission resource for adjusting the transmission power, the transmission resource for switching the non-transmission time, or the transmission resource for switching the frequency The transmission resource selected from among them is adjusted to avoid interference. Thereby, interference can be avoided in the whole system. Further, by performing communication while avoiding interference, communication can be performed while using the same channel, and frequency use efficiency can be increased.

<Second Embodiment>
Next, transmission resource selection processing for reducing interference according to the second embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate and the base station 120 and the terminal station 121 communicate, and an example of recognizing interference between the base station 110 and the terminal station 121 is shown. .

  First, the base station 110 receives pilot signals from a terminal station and a base station that can be received by the base station 110, receives propagation channel information of each station and a number for identifying (identifying) a radio station, and the propagation channel The interference power observed from each station is calculated from the information, and the number and power for identifying the radio station are stored for those that have a certain level of power. Next, at a timing different from that of the base station 110, the terminal station 121 stores the interference power of the interference station that interferes with the terminal station 121 and a number that identifies the wireless station, using the same method as the base station 110. Based on this information, similarly to the first embodiment described above, negotiation is performed and transmission resources to be adjusted are determined.

  In this embodiment, it is possible to obtain interference station information that interferes with the local station by receiving pilot signals at different timings.

<Third Embodiment>
Next, transmission resource selection processing for reducing interference according to the third embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate and the base station 120 and the terminal station 121 communicate, and transmission when avoiding interference between the base station 110 and the terminal station 121 is performed. Indicates how to select a resource.

  When the base station 110 or the terminal station 121 has a plurality of transmission resources, there may be a transmission resource that cannot be selected depending on the radio station. For example, when the base station 110 has a plurality of antennas but the terminal station 121 has only a single antenna, the terminal station 121 has a low degree of freedom in antennas, so that transmission beam communication can be performed. Can not. In addition, there are cases where there is no available frequency, the transmission time cannot be adjusted by carrier sense, or the transmission power is too low to communicate with a terminal that originally wants to communicate.

  Therefore, in this embodiment, various transmission resources are provided, and the optimum transmission resource is determined from each transmission resource that can be set by the radio station. In this embodiment, when selecting a transmission resource, it is possible to avoid interference and perform communication by having various transmission resources, regardless of the performance of the wireless station and environmental problems.

<Fourth Embodiment>
Next, transmission resource selection processing for reducing interference according to the fourth embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the base station 110 and the terminal station 121 is performed. An example of resource notification is shown.

  After obtaining information that the base station 110 and the terminal station 121 are interfering stations by the method using the pilot signal shown in the second embodiment, the base station 110 selects the terminal station 121 from the base station 110. Notify the transmitted resource. If the terminal station 121 can communicate using the same transmission resource as the notified transmission resource, the terminal station 121 performs communication using the notified transmission resource. When transmission is not possible using the notified transmission resource, the terminal station 121 notifies the base station 110 of other transmission resources. When the base station 110 can transmit using the transmission resource notified from the terminal station 121, communication is performed using the notified transmission resource. When the base station 110 cannot transmit even the transmission resource notified from the terminal station 121, it notifies other transmission resources and repeats the above-described processing.

  In addition, the base station 110 notifies the terminal station 121 of all available transmission resources in advance, and the terminal station 121 notifies the base station 110 of available transmission resources and performs communication.

  In this embodiment, the transmission resources can be recognized from each other by notifying the transmission stations directly to the radio stations that are interfering stations.

<Fifth Embodiment>
Next, transmission resource selection processing for reducing interference according to the fifth embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the base station 110 and the terminal station 121 is performed. An example in which the resource is notified via the terminal station 113 is shown.

  The transmission resource selected by the base station 110 is notified to the terminal station 113, and the terminal station 113 notifies the terminal station 121. Also, the transmission resource selected by the terminal station 121 is notified to the terminal station 113, and the terminal station 113 notifies the base station 110. The base station 110 and the terminal station 121 communicate using the notified transmission resource. Further, the base station 110 and the terminal station 121 notify the terminal station 113 of selectable transmission resources, and the terminal station 113 sets the transmission resources that can be selected by both stations from the transmission resources notified from the terminal station 113 and the terminal station 121, respectively. Notification is made to the base station 110 to perform communication.

  In this embodiment, it is possible to recognize transmission resources from each other by indirectly reporting transmission resources to wireless stations that are interfering stations.

<Sixth Embodiment>
Next, transmission resource selection processing for reducing interference according to the sixth embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 113 communicate, and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the terminal station 113 and the terminal station 121 is performed. An example is shown in which resources are received by the base station 110 and the base station 120 and are negotiated and then notified to the terminal station 113 and the terminal station 121.

  In this case, as described above, the base station 110 is a station that notifies the transmission resource selected for interference avoidance from among a plurality of transmission resources, that is, an interference avoidance transmission resource notification station. Receive and store information on interfering stations. Also, the base station 120 becomes an interference avoidance transmission resource notification station, and the base station 120 receives and stores information on the interference station from the terminal station 12K. The base station 110 checks whether there is interference from the base station 120 or a radio station in the cell of the base station 120 based on information obtained from the radio station belonging to the own cell. If present, the base station 120 is notified of the terminal station receiving the interference and each selectable transmission resource.

  Similarly, the base station 120 checks whether there is interference from the base station 110 or the radio station of the base station 110 based on the information obtained from the radio stations belonging to the own cell. To notify. Based on the respective information, the base station 110 and the base station 120 are, for example, the same as in the third embodiment, or the magnitude of interference power, the reduction amount or reduction ratio of throughput, the type of application being communicated, Negotiations such as the priority order of terminal stations are performed, and transmission resources are selected and determined. The determined transmission resource is notified from the base station 110 to the terminal station 113, and the base station 120 to the terminal station 121, and the terminal station 113 and the base station 120 communicate based on the notified transmission resource.

  In this embodiment, the interference avoidance transmission resource notification station negotiates on behalf of the proxy and selects the transmission resource of each radio station, thereby increasing the communication amount of the entire system.

<Seventh Embodiment>
Next, transmission resource selection processing for reducing interference according to the seventh embodiment of the present invention will be described with reference to FIG.

  In this example, it is assumed that the base station 110 and the terminal station 113 communicate, and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the terminal station 113 and the terminal station 121 is performed. The base station 120 is notified of the transmission resource and the radio station received by the base station 110 of the interference avoidance transmission resource notification station in order to determine the resource. The base station 120 uses the transmission resource data belonging to its own cell and the data received from the base station 110 in the same manner as in the third embodiment, or the magnitude of interference power, the reduction amount or reduction ratio of throughput, communication Negotiations such as the type of application being used and the priority order of terminal stations are made, and transmission resources are determined. The determined transmission resource is notified to the base station 110, the base station 110 notifies the terminal station 113, the base station 120 notifies the terminal station 121, and performs communication.

  In this embodiment, one of the two base stations that accommodates two terminal stations in which interference has occurred respectively selects a transmission resource as an interference avoidance transmission resource notification station, thereby causing interference. A transmission resource that avoids is selected. Wireless stations that are in interference with each other can increase the amount of communication by using the selected transmission resource.

<Eighth Embodiment>
Next, transmission resource selection processing for reducing interference according to the eighth embodiment of the present invention will be described using FIG. 6 and FIG. This embodiment is an example using a code book as shown in FIG.

  The code book manages rules such as directivity, frequency, transmission power level, non-transmission time, etc. of a certain shape as numbers in advance between the base station and the terminal station. For example, when a plurality of directivities are exchanged between a base station and a terminal station and there are L different codebooks, the L different directivities can be changed. In FIG. 6, it is assumed that directivity in four directions is handled as code books B1 to B4. Note that the base station and the terminal station store, for example, these codebooks B1 to B4 in a storage unit included therein.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the base station 110 and the terminal station 121 is performed. An example of notifying a resource as a code book is shown. The radio station includes a code book describing a plurality of transmission beam patterns. The base station 110 determines a codebook that is not suitable for the base station from the codebooks of the terminal station 121 giving the interference acquired by the base station and the propagation channel information between the base station 110 and the terminal station 121. In this case, it is determined that the code books B3 and B4 may interfere with the terminal station 121. The base station 110 notifies the terminal station 121 of the determined code book.

  Similarly to the base station 110, the terminal station 121 notifies the base station 110 of a code book that is not suitable for the own station. The terminal station 121 can receive the codebooks B1 and B4, but since the codebook B4 is determined to be interference, the terminal station 121 requests to communicate with the base station 110 using the codebook B1. Send. Both stations communicate using transmission resources corresponding to the received codebook.

  FIG. 7 shows a flowchart for realizing this example. First, assuming that there are L codebooks, received power and interference power are measured for each different codebook.

  First, the code book number is set to N = 1 (step S101), and N is incremented (step S102), and the following operation is performed on the code books from N = 1 to L. In step S103, the base station transmits a pilot signal with the codebook Nth directivity to the terminal station under its cell. A pilot signal is a signal sequence in which a base station and a terminal station become known signals from each other, and is generally used as an exchange between the base station and the terminal station in a normal wireless communication system. At this time, the base station stops communication in other cells by cooperating with other base stations in advance.

  In step S104, if the received power is a threshold value for each terminal station, it is determined that the Nth codebook can be used, and the information is returned to the base station. It is determined whether or not N = L (step S105), and steps S103 to S105 are repeated for codebooks of N = 1 to L. In the example of FIG. 4, the terminal station 111 corresponds to sending to the base station 110 that communication is possible if the directivity of the codebooks B1 and B4.

  Next, M = 1 is set (step S106), and M is incremented (step S107), and the following operation is performed from M = 1 to L. In step S108, the base station transmits a pilot signal with the codebook BM (1-L) -th directivity to the terminal stations under other cells. At this time, the own cell terminal station stops communication. In step S109, if the interference power of the other cell is a threshold value, it is determined that the codebook cannot be used, and the information is returned to the base station. In the example of FIG. 4, the terminal station 121 corresponds to sending to the base station 110 that there is a problem with interference if the directivity of the codebooks B3 and B4. Until M = L (step S110), the processes of steps S108 to S109 are repeated.

  Finally, as step S111, the base station determines a codebook to be used for the terminal station of the own cell so as to satisfy the conditions of steps S104 and S109 from the information of steps S104 and S109. For example, in the example of FIG. 4, the codebooks B1 and B4 are possible from the terminal station 111, and the codebooks B3 and B4 are loads from the terminal station 121. The terminal station 111 is determined to transmit using the code book B1.

  In this embodiment, in order to notify the transmission resource, a lot of information needs to be notified. By reducing the data notified by the code book, it is possible to reduce the overhead generated when notifying and increase the communication amount.

<Ninth Embodiment>
Next, transmission resource selection processing for reducing interference according to the ninth embodiment of the present invention will be described with reference to FIG. In this embodiment, instead of the codebook of the transmission beam pattern in the eighth embodiment, a codebook of transmission power level, a codebook of non-transmission time, or a codebook of frequency is notified.

  In this example, it is assumed that the base station 110 and the terminal station 111 communicate, and the base station 120 and the terminal station 121 communicate, and a code is used to avoid interference between the base station 110 and the terminal station 121. An example of notification using a book will be shown. Notification amount by notifying the code book indicating the transmission power that causes interference instead of the code book indicating the transmission beam pattern, the code book indicating the time received by the base station 110, or the code book indicating the frequency to be used Can be reduced.

  In this embodiment, in order to notify the transmission resource, a lot of information needs to be notified. By reducing the data notified by the code book, it is possible to reduce the overhead generated when notifying and increase the communication amount.

<Tenth Embodiment>
Next, transmission resource selection processing for reducing interference according to the tenth embodiment of the present invention will be described with reference to FIG. In this example, a code book is notified instead of the transmission resource of the sixth embodiment.

  In this example, it is assumed that the base station 110 and the terminal station 113 communicate, and the base station 120 and the terminal station 121 communicate, and transmission for avoiding interference between the terminal station 113 and the terminal station 121 is performed. An example in which resources are notified as a code book via an interference avoidance notification station will be described.

  In this embodiment, in order to notify the transmission resource, a lot of information needs to be notified. By reducing the data notified by the code book, it is possible to reduce the overhead generated when notifying and increase the communication amount.

  The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the gist of the present invention.

1, 2, 4 Communication cells 110, 120, 130 Base station 110 Base stations 111 to 113, 121 to 123, 131 to 133 Terminal stations 201-1 to 201-Na Antenna 202 Signal switching unit 203 Signal acquisition unit 204 Interfering station Information estimating unit 205 Interfering station information generating unit 206 Transmitting units 301-1 to 301Na Antenna 302 Signal switching unit 303 Signal acquiring unit 304 Interfering station information estimating unit 305 Interfering station notification detecting unit 306 Interfering station negotiation determining unit 307 Interfering station information generating unit 308 Transmitter

Claims (7)

A wireless communication system comprising a plurality of wireless stations,
The radio station is
Interference estimation means for estimating the presence of a radio station that serves as an interference station for the own station;
A first transmission resource having a transmission beam as an element, a second transmission resource having a transmission power as an element, and a third transmission resource having a transmission timing as an element when there is a radio station serving as an interference station; Transmitting means for selecting and adjusting at least one transmission resource of the fourth transmission resources having a transmission frequency as an element;
A wireless communication system comprising: The transmitting means of the wireless station is
Notifying the interference station of the transmission resource selected by the own station,
The interference station is
In response to the notification of the transmission resource from the radio station, one of the transmission resources of the local station is selected, the selected transmission resource is notified to the radio station, and the selected transmission Adjust resources,
The wireless communication system according to claim 1. A notification unit for notifying a transmission resource that avoids interference to a radio station in which interference occurs;
Comprising a base station comprising
The radio station is
Adjusting the transmission resource notified from the base station;
The radio communication system according to claim 1 or 2. The radio station is
A first codebook describing the first resource, a second codebook describing the second resource, a third codebook describing the third resource, and the fourth resource A storage unit storing at least one of the fourth codebooks with
With
When there is a radio station that is an interfering station for the local station, one of the first to fourth codebooks is selected, and the selected codebook is notified to the interfering station The radio communication system according to any one of claims 1 to 3, wherein the resource described in the selected code book is adjusted. An antenna for transmitting and receiving signals;
A signal switching unit that switches between transmission and reception of the antenna unit;
A signal acquisition unit for acquiring a signal received by the antenna unit;
By analyzing an output signal of the signal acquisition unit, an interference station is detected, and an interference station information estimation unit that estimates an interference state of the interference station;
An interference station information generation unit that generates an interference station notification signal including information indicating an interference state of the interference station estimated by the interference station information estimation unit;
A transmission unit that transmits a transmission signal including the interference station notification signal via the antenna unit;
Comprising
The transmission unit includes a first transmission resource whose element is a transmission beam, a second transmission resource whose element is transmission power, a third transmission resource whose element is transmission timing, and a transmission frequency which is an element. A radio apparatus characterized in that at least one transmission resource of the fourth transmission resources can be selected and adjusted. An antenna for transmitting and receiving signals;
A signal switching unit that switches between transmission and reception of the antenna unit;
A signal acquisition unit for acquiring a signal received by the antenna unit;
By analyzing an output signal of the signal acquisition unit, an interference station is detected, and an interference station information estimation unit that estimates an interference state of the interference station;
From an output signal of the signal acquisition unit, an interference station notification detection unit that detects an interference station notification signal including information on the detected interference station, and
From the interference state and the interference station notification signal, an interference station negotiation determination unit that determines whether or not they are mutual interference stations,
When it is determined that the interference station negotiation determination unit is an interference station, a first transmission resource whose element is a transmission beam, a second transmission resource whose element is transmission power, and a transmission timing A negotiation condition signal for adjusting the selected transmission resource is selected by selecting at least one transmission resource of the own station from the third transmission resource having the element and the fourth transmission resource having the transmission frequency as the element. An interference station information generating unit to generate,
A transmission unit that transmits the transmission signal including the negotiation condition signal via the antenna unit, and adjusts the selected transmission resource;
A wireless device comprising: A wireless communication method used in a wireless communication system including a plurality of wireless stations,
The interference estimation means provided in the radio station executes a procedure for estimating the presence of a radio station that is an interference station for the own station,
When there is a radio station serving as an interference station, the transmission means included in the radio station has a first transmission resource having a transmission beam as an element, a second transmission resource having a transmission power as an element, and transmission timing. Executing a procedure of selecting and adjusting at least one transmission resource of a third transmission resource having an element and a fourth transmission resource having a transmission frequency as an element;
A wireless communication method.

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