JP5923921B2 - Radio relay station antenna control method, radio relay station - Google Patents

Description

  The present invention relates to an antenna control method for a radio relay station and a radio relay station.

In recent years, the standardization of a wireless communication system for realizing high-capacity and high-speed wireless communication has been developed.
For example, the Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.16 working group has a one-to-many connection that allows multiple mobile stations (Mobile Station, MS) to connect to a radio base station (Base Band Station, BS) ( A point-to-multipoint (P-MP) type communication system is defined. Specifically, IEEE802.16d (IEEE802.16-2004), which is a standard for fixed communication applications, and IEEE802.16e (IEEE802.16e-2005), a standard for mobile communication applications, are specified. Yes. A plurality of specifications are standardized in the IEEE802.16d and IEEE802.16e physical layers, and technologies such as Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA) are mainly used.

In a one-to-many connection wireless communication system, a wireless base station connects to a plurality of mobile stations located within the communication area of the own station.
However, the characteristics of the wireless transmission path between the mobile station and the wireless base station can be deteriorated by the influence of the topography and the cityscape. For this reason, for example, when there is an obstacle such as a building on the radio transmission path between the mobile station and the radio base station, in order to enable communication between the mobile station and the radio base station, It is necessary to construct a wireless transmission path that bypasses the object.

  In addition, there is a need to provide communication services to mobile stations located outside the wireless base station communication area, for example, when events such as sports and games are held outside the wireless base station communication area. Can occur.

  Furthermore, when a communication network environment is damaged due to the occurrence of a natural disaster or the like, it is necessary to provide a communication network so that the mobile station can connect to other radio base stations.

Therefore, in order to meet the above-described necessity, it is conceivable to install a radio relay station (Relay Station, RS) that relays radio communication between the mobile station and the radio base station.
Radio communication between the mobile station and the radio base station is performed via a radio relay station. That is, the radio relay station reconstructs data received from the radio base station and transmits the reconstructed data to the mobile station. The radio relay station reconstructs the data received from the mobile station and transmits the reconstructed data to the radio base station.

  Thus, by interposing the radio relay station in the radio communication between the mobile station and the radio base station, the communication area and communication network for the mobile station can be expanded.

  In addition, based on the position of the mobile station calculated by the GPS signal from the Global Positioning System (GPS) satellite and the location information of the base station stored in the mobile station, the base station with the shortest distance from the mobile station is determined as the mobile station. A technique for selecting a base station to communicate with is known.

  If the first emergency call device mounted on the vehicle cannot transmit emergency call information to the emergency call center, the second emergency call device mounted on another vehicle in a position where it can communicate with the first emergency call device A technique for transmitting to a reporting device is known.

  Technology that selects the base station with which the radio base station communicates by scanning the entire reception range by discretely changing the beam direction of the antenna, and repeatedly scanning the range with high reception intensity while gradually narrowing the beam width It has been known.

JP-A-9-261716 JP 2001-357480 A WO2008 / 111142 Publication

IEEE Std 802.16TM-2004, “Interference-Aware IEEE 802.16 WiMax Mesh Networks”, December 5, 2005 IEEE Std 802.16eTM-2005, “Fast Handover Algorithm for IEEE 802.16e Broadband Wireless Access System”, April 10, 2006

  When a radio relay station is installed according to the necessity as described above, it is required that the antenna of the radio relay station form a beam in a short time in the direction of an optimal base station with little interference.

  In this regard, when a directional antenna whose directivity cannot be changed electrically is used for the antenna of the radio relay station, the worker who installs the radio relay station must point the radio relay station antenna in the desired radio base station direction. It is necessary to turn it physically. For this reason, it takes time to install the antenna.

  In addition, when a directional antenna that can electrically change the directivity, such as an adaptive array antenna, is used, in the conventional technology, in order to select an optimal radio base station, the beam direction of the radio relay station antenna is discrete. It is necessary to scan the entire reception range while changing it. For this reason, it takes time to select an optimal radio base station.

  An object of the present invention is to provide an antenna control method for a radio relay station that forms a beam in a short time in the direction of an optimal base station with little interference, and a radio relay station including the antenna control method.

An antenna control method for a radio relay station according to an embodiment acquires position information of a radio relay station, and is based on the acquired position information and position information of a plurality of base stations stored in a storage unit of the radio relay station. Then, select a predetermined number of base stations from a plurality of base stations in ascending order of the distance from the radio relay station as the connection candidate base stations of the radio relay station, and select the selected connection candidate bases. Based on the radio propagation environment data of the transmission path between the station and the radio relay station, select the connection base station of the radio relay station from the connection candidate base stations, and set the electrical directivity of the radio relay station. When the directivity of the changeable antenna is controlled in the direction of the selected connection base station, the null point of the antenna is formed in the direction of the base station of the connection candidate that is not selected, and communication is not performed. Scan the antenna Get the propagation environment data, when detecting the disturbance wave from the acquired radio wave propagation environment data, in a direction of detecting a disturbance to form a null point of the antenna.

The radio relay station according to the embodiment includes an antenna that can electrically change directivity, an acquisition unit that acquires position information of the radio relay station, a storage unit that stores position information of a plurality of base stations, and a radio A receiving unit that receives radio wave propagation environment data of a transmission path between a relay station and a base station that is a candidate for connection of a wireless relay station via an antenna, and a position information and storage unit of the wireless relay station acquired by the acquiring unit Based on the stored location information of a plurality of base stations, select a predetermined number of base stations from a plurality of base stations in order of short distance to the radio relay station as connection candidate base stations. A processing unit that selects a connection base station of the radio relay station from the connection candidate base stations based on the radio wave propagation environment data acquired by the reception unit, and controls the antenna directivity in the direction of the connection base station; only including, the processing section, Performs control to form a null point of the antenna in the direction of the connection candidate base station that is not selected, and the receiving unit scans the antenna to acquire radio wave propagation environment data and performs processing when communication is not being performed. When the interference wave is detected from the acquired radio wave propagation environment data, the unit performs control to form an antenna null point in the direction in which the interference wave is detected .

  According to the embodiment, the beam of the radio relay station antenna can be formed in a short time in the direction of the optimum base station with little interference.

It is a hardware block diagram of the radio relay station according to an embodiment. It is an example of the radio wave propagation environment data table according to the embodiment. It is a block diagram of the adaptive array antenna according to an embodiment. It is a main beam width determination flowchart of the radio relay station according to the embodiment. It is the optimal base station selection flowchart according to the embodiment. It is a beam direction adjustment flowchart according to the embodiment. It is a beam direction adjustment flowchart according to the embodiment. It is an antenna pattern update flowchart according to the embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a hardware configuration diagram of a radio relay station according to the embodiment.
As shown in FIG. 1, the radio relay station 100 includes a base station side transmission / reception control device 110, a base station side transmission / reception processing device 120, an adaptive array antenna control device 130, and an adaptive array antenna 140. The radio relay station 100 includes a mobile station side transmission / reception control device 150, a mobile station side transmission / reception processing device 160, an antenna 170, a GPS signal reception device 180 as an example of an acquisition unit, and a GPS signal reception antenna 190.

  The base station side transmission / reception control device 110 controls the base station side transmission / reception processing device 120. The base station side transmission / reception control device 110 includes a processor 111 which is an example of a processing unit, and a memory 112 which is an example of a storage unit.

  In the embodiment, the memory 112 stores position information of one or more radio base stations in advance. The location information stored in advance includes radio base station identification information, transmission frequency, latitude, and longitude.

  The memory 112 stores position information such as latitude and longitude where the wireless relay station 100 is installed. The position information of the radio base station 100 is acquired based on the transmission signal of the GPS satellite received by the GPS signal receiving device 180 via the GPS signal receiving antenna 190 when the radio relay station is installed, for example.

  Further, the memory 112 stores radio wave propagation characteristic data of a transmission path between the radio relay station 100 and each radio base station. The radio wave propagation characteristics are measured through the following processing, and the measured data is stored in the memory 112.

  The processor 111 calculates the direction in which the radio base station is located based on the radio relay station 100 based on the position information of the radio base station and the position information of the radio relay station 100 stored in the memory 112. The adaptive array antenna control apparatus 130 controls the main beam of the adaptive array antenna 140 in the direction of the calculated radio base station based on an instruction from the processor 111. Then, based on the received signal from the radio base station received via the adaptive array antenna 140, the radio wave propagation environment is measured by the receiving unit 122. The measured radio wave propagation environment is, for example, a reception level. The measured radio wave propagation environment data is stored in the memory 112.

  FIG. 2 is an example of a radio wave propagation environment data table according to the embodiment. As shown in FIG. 2, the measured frequency, the angle in the horizontal plane indicating the measured beam direction, and the reception level are stored in the memory 112.

  In addition to the radio wave propagation environment data shown in FIG. 2, the data acquisition date and the main beam width at the time of measurement are associated with the measured frequency, the measured angle in the horizontal plane, and the reception level. May be further stored.

The base station side transmission / reception processing device 120 includes a transmission unit 121 that processes a transmission signal to the radio base station, and a reception unit 122 that processes a reception signal from the radio base station.
The mobile station side transmission / reception control device 150 controls the mobile station side transmission / reception processing device 160.

The mobile station side transmission / reception processing device 160 includes a transmission unit 161 that processes a transmission signal to the mobile station and a reception unit 162 that processes a reception signal from the mobile station.
Adaptive array antenna control apparatus 130 controls the directivity of adaptive array antenna 140 such as the beam width, beam direction, and null point.

  The adaptive array antenna 140 is an antenna for transmitting a signal to the radio base station and receiving a signal from the radio base station. The antenna 170 is an antenna for transmitting a signal to the mobile station and receiving a signal from the mobile station.

  The adaptive array antenna 140 is an antenna in which a plurality of antenna elements 140-1 to 140-n are arranged in an array, and the directivity can be changed electrically. That is, adaptive array antenna 140 can form a beam in a direction in which a signal is to be transmitted and received, and can form null points in the interference wave direction and the interference wave direction.

FIG. 3 is a configuration diagram of an adaptive array antenna according to the embodiment.
As shown in FIG. 3, antenna elements 141-1 to 141-n constituting adaptive array antenna 140 are respectively associated with corresponding amplitude adjusters 142-1 to 142-n and variable phase shifters 143-1 to 143-n. Connected. Receiving signals from the antenna elements 141-1 to 141-n that have passed through the amplitude adjusters 142-1 to 142-n and the variable phase shifters 143-1 to 143-n are added by the adder 144 and output.

  The directivity control of the adaptive array antenna 140 is performed by changing the phase and amplitude of each signal from the antenna elements 141-1 to 141-n arranged away from each other by using the amplitude adjusters 142-1 to 142-n and the variable phase shifters. It is performed by controlling using 143-1 to 143-n. The control using the amplitude adjusters 142-1 to 142-n and the variable phase shifters 143-1 to 143-n enhances the received radio waves arriving from the radio base station direction, and the arrival directions of the interference wave and the interference wave. The received radio wave can be weakened.

  In the embodiment, when the radio relay station is installed, the base station side transmission / reception control device 110, the reception unit 122, and the adaptive array antenna control device 130 are used to direct the beam of the adaptive array antenna 140 toward the optimal radio base station direction. Turn.

  That is, the processor 111 is connected to the radio relay station 100 based on the position information of the radio base station and the position information of the radio relay station 100 stored in the memory 112 and the radio wave propagation environment data measured by the receiving unit 122. A radio base station is selected. Then, the adaptive array antenna control device 130 directs the main beam of the adaptive array antenna toward the selected radio base station.

Further, the antenna pattern of the adaptive array antenna 140 is formed by the adaptive array antenna control device 130 based on an instruction from the processor 111.
That is, a null point of adaptive array antenna 140 is formed in the direction of another radio base station that is not selected as a radio base station connected to radio relay station 100. In addition, when the adaptive array antenna 140 is scanned to detect an interference wave and an interference wave, null points are also formed in the interference wave direction and the interference wave direction.

When the beam of adaptive array antenna 140 is directed to an optimal base station and a desired antenna pattern is formed, operation of radio relay station 100 is started.
That is, a received signal from the radio base station is transmitted to the mobile station via adaptive array antenna 140, adaptive array antenna control apparatus 130, receiving unit 122, transmitting unit 161, and antenna 170. The reception signal, reception frequency, and reception timing from the radio base station are controlled by the base station side transmission / reception control device 110. The transmission signal, transmission frequency, and transmission timing to the mobile station are controlled by the mobile station side transmission / reception control device 150.

  A received signal from the mobile station is transmitted to the radio base station via the antenna 170, the receiving unit 162, the transmitting unit 121, the adaptive array antenna control device 130, and the adaptive array antenna 140. In addition, the reception signal, reception frequency, and reception timing from the mobile station are controlled by the mobile side transmission / reception control device 150. The transmission signal, transmission frequency, and transmission timing to the radio base station are controlled by the radio base station side transmission / reception control device 150.

  In some embodiments, after the wireless relay station 100 is installed, the adaptive array antenna 140 is periodically scanned to measure radio wave propagation characteristics. Then, based on the measurement result, the directivity of adaptive antenna 140 is changed so that interference due to interference waves and jamming waves is avoided.

  As described above, the control of the adaptive array antenna 140 according to the embodiment is based on the position information of the radio relay station 100 and the radio base station, and the radio wave propagation environment data of the transmission path between the radio relay station 100 and the radio base station. Based on.

  That is, in the embodiment, when selecting a radio base station to be connected to the radio relay station 100, first, based on the direction in which the radio base station is located from the radio relay station 100 and the distance to the radio base station, A radio base station that is a connection candidate of the relay station 100 is selected.

  As described above, the position information of the radio base station is stored in the memory 112 in advance. Further, the position information of the wireless relay station 100 is acquired based on a received signal from a GPS satellite or the like when the wireless relay station 100 is installed, and stored in the memory 112. Therefore, from the position information of the radio base station and the radio relay station 100 stored in the memory 112, the radio base station direction with respect to the radio relay station 100 and the distance from the radio base station can be calculated.

  By using the calculated radio base station direction and the distance to the radio base station, it is optimal in a state with less interference compared to the method of changing the directivity of the adaptive array antenna over the entire reception range, whether discrete. Beam forming toward the base station can be executed in a short time.

  Further, in the embodiment, an optimal radio base station connected to the radio relay station 100 is determined as a connection candidate radio base station using radio wave propagation environment data of a transmission path between the radio relay station 100 and the connection candidate radio base station. Selected from. Then, the directivity of adaptive array antenna 140 is controlled in the optimal base station direction.

  The radio wave propagation characteristics of the transmission path between the radio relay station 100 and the radio base station can be deteriorated by the influence of topography and cityscape. For example, when an obstacle such as a building exists between the radio base station and the radio relay station 100, the communication quality between the radio base station and the radio relay station 100 deteriorates due to the influence of the obstacle. Therefore, it cannot be said that the quality of communication with the radio base station located at the shortest distance from the radio relay station 100 is necessarily higher than the communication quality with other radio base stations.

  In this regard, in the case of a mobile station that is planned to be operated while moving from place to place, the radio wave propagation characteristics of the transmission path between the radio base station and the mobile station change according to the moved position and moving speed. For this reason, the communication quality between the mobile station and the radio base station may be improved by moving the mobile station again even if it temporarily deteriorates due to the presence of an obstacle at the current location of the mobile station. There is.

  On the other hand, in the case of a radio relay station scheduled to be operated at a certain location, the radio wave propagation characteristics of the transmission path between the radio relay station and the radio base station change in a short time from the time of installation. There is nothing. For this reason, the communication quality between the radio relay station and the radio base station is not improved in a short time when it deteriorates due to the presence of an obstacle such as a building on the transmission path.

  Therefore, in the embodiment, the radio relay station 100 is connected based on the distance between the radio base station and the radio relay station 100 and the radio wave propagation environment of the transmission path between the radio base station and the radio relay station 100. Determine the optimal radio base station.

A method for controlling the antenna 140 of the radio relay station 100 according to the embodiment will be described with reference to FIGS.
FIG. 4 is a main beam width determination flowchart of the radio relay station according to the embodiment.

In step S101, the initial value, minimum value, and subtraction angle of the main beam width of adaptive array antenna 140 are set.
The main beam width is the angle between points where the power in the peak direction of the main beam of the antenna is reduced by 3 decibels (dB). In an adaptive array antenna, the main beam width can be changed. Therefore, in the embodiment, when adjusting the main beam width, an initial value (for example, 10 degrees) of the main beam width of the adaptive array antenna 140 is set. In addition, a step angle for subtracting the main beam width is set. Then, the minimum value of the main beam width allowed when the main beam width is adjusted by subtracting from the initial value is set.

  In step S102, the main beam of adaptive array antenna 140 having the initial value set in step 101 is set in the direction of the radio base station located at the shortest distance from radio relay station 100 by adaptive array antenna control apparatus 130. The setting of the main beam direction of the adaptive array antenna 140 is based on the position information of the radio base station 100 pre-stored in the memory 112 and the position information of the radio relay station 100 calculated based on the received signal from the GPS satellite, etc. This is executed according to an instruction from the processor 111.

  In step S103, the reception unit 122 sets the reception frequency to the transmission frequency of the radio base station located at the shortest distance based on the instruction from the processor 111. The transmission frequency of the radio base station located at the shortest distance is stored in advance in the memory 112 as position information of the radio base station.

  In step S104, the reception unit 122 measures the reception level of the received signal from the radio base station located at the shortest distance received via the adaptive array antenna 140 having the main beam in the direction set in step S102. In step S105, the measured reception level is recorded in the memory 112 together with the direction of the main beam, the reception frequency, and the data acquisition date and time.

  In step S106, the direction of the main beam of the adaptive array antenna 140 is changed by the adaptive array antenna control device 130 by the width of the main beam in the plus direction from the direction set in step 102. For example, when the main beam width is set to 10 degrees, the direction of the main beam is changed by 10 degrees more than the direction of the main beam set in step 102.

  In step S107, the reception unit 122 measures the reception level of the received signal from the radio base station with the shortest distance received via the adaptive array antenna 140 having the main beam in the direction changed in step S106. In step S108, the measured reception level is recorded in the memory 112 together with the direction and frequency of the main beam.

  In step S109, the direction of the main beam of the adaptive array antenna 140 is changed by the adaptive array antenna control apparatus 130 by the width of the main beam in the minus direction from the direction set in step 102. For example, when the main beam width is set to 10 degrees, the direction of the main beam is changed by minus 10 degrees from the main beam direction set in step 102.

  In step S110, the receiving unit 122 measures the reception level of the received signal from the radio base station with the shortest distance received via the adaptive array antenna 140 having the main beam in the direction changed in step S109. In step S111, the measured reception level is recorded in the memory 112 together with the direction and frequency of the main beam.

  In step S112, the processor 111 compares the reception level measured in steps S107 and S110 with the reception level measured in step S104 with reference to the memory 112. Then, the processor 111 determines whether or not the reception levels measured in step S107 and step S110 are smaller than the reception level measured in step S104.

  As a result of the determination in step S112, when the reception level measured in step S107 and step S110 is smaller than the reception level measured in step S104 (“YES” in step S112), the main beam of adaptive array antenna 140 The width is determined to the currently set main beam width (step S115).

  On the other hand, when the reception level measured in step S107 and step S110 is the same as the reception level measured in step S104 (“NO” in step S112), the processor 111 determines that the currently set main beam width is It is determined whether or not it is equal to the minimum value of the main beam width set in step S101 (step S113).

  If the result of determination in step S113 is that the currently set main beam width is equal to the minimum value of the main beam width set in step S101 (“YES” in step S113), the width of the main beam of adaptive array antenna 140 Is determined to the currently set main beam width (step S115).

  On the other hand, when the currently set main beam width is larger than the minimum value of the main beam width set in step S101 (“NO” in step S113), the currently set main beam width is set in step S101. The subtraction angle is changed to a smaller value (step S114). And the process after step S103 is repeated about the main beam of the adaptive array antenna 140 which has the beam width set by step 114. FIG.

FIG. 5 is an optimal base station selection flowchart according to the embodiment.
In step S201, the processor 111 sets 1 as a radio base station that is a connection candidate of the radio relay station 100 based on the position information of one or more radio base stations and the position information of the radio relay station 100 stored in the memory 112 in advance. Select one or more radio base stations. For example, the processor 111 selects three radio base stations as connection candidate radio base stations in order of increasing distance from the radio relay station 100.

  In step S202, the main beam of adaptive array antenna 140 having the main beam width determined in step 115 of FIG. 4 is set by adaptive array antenna control apparatus 130 in the direction of one radio base station as a connection candidate. The setting of the main beam direction is executed according to an instruction from the processor 111 based on the position information of the connection candidate radio base station and the position information of the radio relay station 100 stored in advance in the memory 112.

  In step S203, the receiving unit 122 sets the reception frequency to the transmission frequency of one wireless base station that is a connection candidate based on an instruction from the processor 111. The transmission frequencies of the connection candidate radio base stations are stored in advance in the memory 112 as position information of the radio base stations.

  In step S204, the radio wave having the frequency set in step S204 from the radio base station direction set in step S202 is received through the adaptive array antenna 140. Then, the receiving unit 122 measures the reception level of the received radio wave as the radio wave propagation environment of the transmission path between the connection-target radio base station set in step 202 and the radio relay station 100.

  In step S205, the reception level measured in step S204 is recorded in the memory 112 together with the measured reception frequency and the measured main beam direction. The data acquisition date and the main beam width at the time of measurement may be further recorded in the memory 112 in association with the reception frequency, the main beam direction, and the reception level.

  In step S206, the processor 111 transmits the transmission path between the connection candidate radio base station set in step 202 and the radio relay station 100 for all transmission frequencies of the connection candidate radio base station selected in step S201. It is determined whether or not the radio wave propagation environment data is acquired.

  As a result of the determination in step S206, if radio wave propagation environment data has not been acquired for all transmission frequencies of the connection candidate radio base stations ("NO" in step S206), the process returns to step S203. In step S203, based on an instruction from the processor 111, the reception unit 122 sets a reception frequency to a transmission frequency for which radio wave propagation environment data has not been acquired. And the process after step S204 is continued.

  On the other hand, when radio wave propagation environment data is acquired for all transmission frequencies of the connection candidate radio base stations (“YES” in step S206), the processor 111 performs radio wave propagation for all directions in which the connection candidate radio base stations are located. It is determined whether environmental data has been acquired (step S207).

  If the result of determination in step S207 is that radio wave propagation environment data relating to all directions in which the connection candidate radio base stations are located has not been acquired, processing returns to step S202. In step S202, adaptive array antenna control apparatus 130 sets the main beam of adaptive array antenna 140 in the direction in which the connection candidate radio base station for which radio wave propagation environment data has not been acquired is located, based on an instruction from processor 111. To do. And the process after step S203 is continued.

On the other hand, if radio wave propagation environment data regarding all directions in which the connection candidate wireless base stations are located (“YES” in step S207), the process proceeds to step S208.
In step S208, the processor 111 refers to the radio wave propagation environment data recorded in the memory 112, and selects the radio base station positioned in the direction of the highest reception level as the optimum radio base station to be connected to the radio relay station 100. To do.

6A and 6B are beam direction adjustment flow diagrams according to embodiments.
In step S301, a fine adjustment angle and a fine adjustment angle range are set. The fine adjustment angle range refers to an angle at which fine adjustment in the plus direction or minus direction is performed around the direction in which the optimum radio base station selected in step S208 in FIG. 5 is located. The fine adjustment angle refers to a step angle for changing the direction of the main beam.

  In step S302, the processor 111 instructs the adaptive array antenna control apparatus 130 to form the main beam of the adaptive array antenna 140 in the direction in which the optimum radio base station selected in step S208 of FIG. 5 is located. . Then, the adaptive array antenna control apparatus 130 forms the main beam of the adaptive array antenna 140 in the direction in which the optimum radio base station is located.

  In step S303, the reception unit 122 sets the reception frequency to the transmission frequency of the optimum radio base station based on the instruction from the processor 111. In step S304, the receiving unit 122 measures the reception level of the received signal from the optimum radio base station received via the adaptive array antenna 140 having the main beam formed in step S302. In step S305, the measured reception level is recorded in the memory 112 as a set value together with the direction of the main beam.

  In step S306, the adaptive array antenna control apparatus 130 forms the main beam of the adaptive array antenna 140 in the minus direction by the fine adjustment angle from the optimum radio base station direction.

  In step S307, the receiving unit 122 measures the reception level of the received signal from the optimum radio base station received via the adaptive array antenna 140 having the main beam formed in step S306. In step S308, the measured reception level is recorded in the memory 112 together with the direction of the main beam.

In step S309, the processor 111 determines whether or not the reception level recorded in step S308 is higher than the reception level recorded as a set value.
As a result of the determination in step S309, when the reception level recorded in step S308 is equal to or lower than the reception level recorded as the set value (“NO” in step S309), the process proceeds to step S313.

  On the other hand, when the reception level recorded in step S309 is larger than the reception level recorded as the set value (“YES” in step S309), the reception level recorded in step S308 and the main beam direction are newly set. (Step S310). Then, the process proceeds to step S311.

In step S311, the processor 111 determines whether or not a fine adjustment angle range in the minus direction from the optimal radio base station direction has been measured.
If the result of determination in step S311 is that the fine adjustment angle range in the negative direction from the optimum radio base station direction has not been measured (“NO” in step S311), the process proceeds to step S312. In step S312, based on an instruction from the processor 111, the adaptive array antenna control device 130 forms a main beam in the minus direction by a fine adjustment angle from the currently set main beam direction. And it returns to the process of step S307 and a process is continued.

On the other hand, when the fine adjustment angle range in the minus direction from the selected radio base station direction is measured (“YES” in step S311), the process proceeds to step S313.
In step S313, the adaptive array antenna control apparatus 130 forms the main beam of the adaptive array antenna 140 in the plus direction by a fine adjustment angle from the optimum radio base station direction.

  In step S314, the receiving unit 122 measures the reception level of the received signal from the radio base station received via the adaptive array antenna 140 having the main beam formed in step S313. In step S315, the measured reception level is recorded in the memory 112 together with the direction of the main beam.

In step S316, the processor 111 determines whether or not the reception level recorded in step S315 is higher than the reception level recorded as a set value.
As a result of the determination in step S316, if the reception level recorded in step S315 is equal to or lower than the reception level recorded as the set value (“NO” in step S316), the process proceeds to step S320.

  On the other hand, when the reception level recorded in step S315 is larger than the reception level recorded as the set value (“YES” in step S316), the reception level and main beam direction recorded in step S315 are set as new settings. Recording is performed (step S317). Then, the process proceeds to step S318.

In step S318, the processor 111 determines whether or not the fine adjustment angle range in the plus direction from the optimum radio base station direction has been measured.
If the result of determination in step S318 is that the fine adjustment angle range in the positive direction from the optimum radio base station direction has not been measured (“NO” in step S318), the process proceeds to step S319. In step S319, the adaptive array antenna control apparatus 130 forms a main beam in the plus direction by a fine adjustment angle from the currently set main beam direction. And it returns to the process of step S314 and a process is continued.

On the other hand, when the fine adjustment angle range in the plus direction from the optimum radio base station direction is measured (“YES” in step S318), the process proceeds to step S320.
In step S320, based on an instruction from the processor 111, the adaptive array antenna control device 130 forms the main beam of the adaptive array antenna 130 in the direction of the main beam recorded as a set value in the memory 112.

  After the main beam is formed in step S320, on the basis of an instruction from the processor 111, the adaptive array antenna control device 130 forms a null point of the adaptive array antenna 140 in the direction in which the radio base station not selected is located. The

  Further, the processor 111 refers to the radio wave propagation environment data recorded in the memory 112 in step S205 of FIG. 5 and receives the radio base station in a direction other than the optimal radio base station direction at the transmission frequency of the optimal radio base station. Search whether a level exists. If the reception level exists as a result of the search, the processor 111 instructs the adaptive array antenna control apparatus 130 to form a null point of the adaptive array antenna 140 in the direction in which the reception level exists. Adaptive array antenna control apparatus 130 forms a null point of adaptive array antenna 140 in the direction in which the reception level exists.

Thus, when the control of the directivity of the adaptive array antenna is completed, the operation of the radio relay station 100 is started.
That is, the radio relay station 100 receives data transmitted from the mobile station via the antenna 170. The radio relay station 100 transmits the reception data from the mobile station to the optimum radio base station connected to the local station 100 via the reception unit 162, the transmission unit 121, and the adaptive array antenna 140.

  Further, the radio relay station 100 receives the data addressed to the mobile station transmitted from the optimum radio base station connected to the local station 100 via the adaptive array antenna 140. Radio relay station 100 transmits reception data addressed to the mobile station via reception unit 122, transmission unit 161, and antenna 170.

FIG. 7 is an antenna pattern update flowchart according to the embodiment.
The radio wave propagation environment on the transmission path between the radio relay station 100 and the radio base station can change even after the operation of the radio relay station 100 starts due to factors such as the construction of a new building that becomes an obstacle.

  Therefore, in the embodiment, even after the operation of the radio relay station 100 is started, the radio wave propagation environment data on the transmission path between the radio relay station 100 and the radio base station is periodically communicated, for example, every month. Get when not. Then, the directivity of adaptive array antenna 140 is changed based on the acquired radio wave propagation environment data. By this change processing, even after the operation of the radio relay station 100 is started, resistance against jamming waves and interference waves is maintained, and good reception quality is maintained.

  In step S401 in FIG. 7, the direction of the main beam of the adaptive array antenna 140 is set by the adaptive array antenna control device 130 based on an instruction from the processor 111.

  The direction of the main beam to be set is changed using the initial value, minimum value, and subtraction angle of the main beam width set in step S101 of FIG. 4, and the direction of the radio base station at the shortest distance from the radio relay station 100 The positive and negative directions centered on. In addition, this is the direction in which the connection candidate radio base station selected in step S201 in FIG. 5 is located. Then, the positive and negative directions centered on the selected optimum radio base station direction are changed using the fine adjustment angle and fine adjustment angle range set in step S301 of FIG.

  In step S402, radio waves having the transmission frequency of the optimum radio base station are received using the adaptive array antenna 140 having the main beam in the set direction. The receiving unit 122 measures the reception level of the received radio wave.

In step S403, the measured reception level is recorded in the memory 112 together with the direction of the main beam.
In step S404, the processor 111 determines whether the reception level in all directions set in step S401 has been measured.

  As a result of the determination in step S404, when the reception level in all directions set in step S401 has not been measured (“NO” in step S404), the process returns to step S401. In step S401, based on an instruction from the processor 111, the adaptive array antenna control apparatus 130 sets the main beam of the adaptive array antenna 140 in a direction not being measured, and the processing in step S402 and subsequent steps is continued.

On the other hand, if the omnidirectional reception level set in step S401 is measured (“YES” in step S404), the process proceeds to step S405.
In step S405, the processor 111 compares the reception level at the previous periodic measurement stored in the memory 112 with the reception level at the current periodic measurement. When the regular measurement is performed for the first time, the reception level measured when the radio relay station 100 is installed is used instead of the reception level at the previous regular measurement.

  As a result of the comparison in step S405, if there is a difference between the reception levels of the two, based on the difference result, the main beam width of the adaptive array antenna 140 is changed, the main beam direction is finely adjusted, and the null point is formed. This is performed by the adaptive array antenna control device 130.

In addition to the processing described above with reference to FIG. 7, the following processing may be executed after the operation of the radio relay station 100 is started.
If the reception unit 122 detects a reception quality deterioration of a predetermined threshold value or higher such that the signal cannot be received from the optimum radio base station after the operation of the radio relay station 100 is started, the adaptive array antenna is not waited for the regular period. 140 control is executed. In this case, the optimal radio base station connected to the radio relay station 100 is reselected by the method for controlling the adaptive array antenna 140 described above with reference to FIGS. 4 to 6, and the directivity of the adaptive array antenna 140 is recontrolled. The In this case, in step S102 of FIG. 4, the main beam of the adaptive array antenna is set in the direction of the radio base station that is the second closest to the radio relay station 100, instead of the radio base station direction of the shortest distance from the radio relay station 100. .

  Further, when a new radio base station is installed after the operation of the radio relay station 100 is started, the position information of the installed new radio relay station is registered in the memory 112. Then, the optimal radio base station connected to the radio relay station 100 is reselected by the method for controlling the adaptive array antenna 140 described above with reference to FIGS. 4 to 6, and the directivity control of the adaptive array antenna 140 is performed again. The

According to the embodiment as described above, when the radio relay station 100 is installed, the antenna 140 of the radio relay station 100 can perform beam forming in the optimum base station direction in a short time with little interference. it can.
In addition, according to the embodiment, even after the operation of the radio relay station 100 is started, it is possible to maintain resistance to interference waves and interference waves and maintain good reception quality.

Regarding the above embodiment, the following additional notes are disclosed.
(Appendix 1)
An antenna control method for a radio relay station,
Get the location information of the wireless relay station,
Based on the acquired location information and location information of a plurality of base stations stored in the storage unit of the radio relay station, select a base station as a connection candidate of the radio relay station,
Based on the radio propagation environment data of the transmission path between the selected connection candidate base station and the wireless relay station, select the connection base station of the wireless relay station from the connection candidate base stations,
An antenna control method, comprising: controlling the directivity of an antenna of the radio relay station whose electrical directivity can be changed in the direction of the selected connected base station.
(Appendix 2)
The antenna control method according to appendix 1, wherein a null point of the antenna is formed in the direction of the base station of the connection candidate that has not been selected.
(Appendix 3)
When communication is not performed, the antenna is scanned to acquire radio wave propagation environment data, and when an interference wave is detected from the acquired radio wave propagation environment data, the antenna is detected in the direction in which the interference wave is detected. The antenna control method according to appendix 2, wherein a null point is formed.
(Appendix 4)
The antenna control method according to appendix 1, wherein the antenna is periodically scanned to acquire radio wave propagation characteristic data, and the directivity characteristic of the antenna is changed based on the acquired radio wave propagation environment data. .
(Appendix 5)
The antenna control method according to appendix 1, wherein the position information of the wireless relay station is acquired using a GPS signal.
(Appendix 6)
An antenna capable of electrically changing directivity;
An acquisition unit for acquiring position information of the wireless relay station;
A storage unit for storing position information of a plurality of base stations;
A receiver that receives radio propagation environment data of a transmission path between the wireless relay station and a base station that is a candidate for connection of the wireless relay station via the antenna;
Based on the position information of the radio relay station acquired by the acquisition unit and the position information of the plurality of base stations stored by the storage unit, the base station of the connection candidate is selected and acquired by the reception unit. A processing unit that selects a connection base station of the wireless relay station from the connection candidate base stations based on the radio wave propagation environment data, and controls the directivity of the antenna in the direction of the connection base station; A wireless relay station comprising:
(Appendix 7)
The radio relay station according to appendix 6, wherein the processing unit forms a null point of the antenna in a direction of a base station that is not selected.
(Appendix 8)
When the processing unit detects a jamming wave from radio wave propagation environment data acquired by scanning the antenna when communication is not being performed, the processing unit sets a null point of the antenna in the direction in which the jamming wave is detected. The radio relay station according to appendix 7, wherein the radio relay station is formed.
(Appendix 9)
The wireless relay station according to appendix 6, wherein the processing unit changes a directivity characteristic of the antenna based on radio wave propagation characteristic data obtained by periodically scanning the antenna.
(Appendix 10)
The wireless relay station according to appendix 6, wherein the acquisition unit acquires position information of the wireless relay station using a GPS signal.

DESCRIPTION OF SYMBOLS 100 Radio relay station 110 Base station side transmission / reception control apparatus 111 Processor 112 Memory 120 Base station side transmission / reception processing apparatus 121 Transmission part 122 Reception part 130 Adaptive array antenna control apparatus 140 Adaptive array antenna 141-1 to 141-n Antenna element 142-1 ˜142-n Amplitude adjusters 143-1 to 143-n Variable phase shifter 144 Adder 150 Mobile station side transmission / reception control device 160 Mobile station side transmission / reception processing device 161 Transmission unit 162 Reception unit 170 Antenna 180 GPS signal reception device 190 GPS reception antenna

Claims (4)

An antenna control method for a radio relay station,
Get the location information of the wireless relay station,
Based on the acquired position information and the position information of the plurality of base stations stored in the storage unit of the wireless relay station, the distance from the plurality of base stations in advance in ascending order of the distance from the wireless relay station. Select a predetermined number of base stations as connection candidate base stations for the wireless relay station,
Based on the radio propagation environment data of the transmission path between the selected connection candidate base station and the wireless relay station, select the connection base station of the wireless relay station from the connection candidate base stations,
Controlling the directivity of the antenna that the radio relay station has electrically changeable directivity in the direction of the selected connection base station ,
Forming a null point of the antenna in the direction of the base station of the connection candidate not selected;
When not communicating, scan the antenna to obtain radio wave propagation environment data,
The antenna control method according to claim 1, wherein when an interference wave is detected from the acquired radio wave propagation environment data, a null point of the antenna is formed also in a direction in which the interference wave is detected .   The antenna control according to claim 1, wherein the antenna is periodically scanned to acquire radio wave propagation characteristic data, and the directivity characteristic of the antenna is changed based on the acquired radio wave propagation environment data. Method.   The antenna control method according to claim 1, wherein the position information of the wireless relay station is acquired using a GPS signal. An antenna capable of electrically changing directivity;
An acquisition unit for acquiring position information of the wireless relay station;
A storage unit for storing position information of a plurality of base stations;
A receiver that receives radio propagation environment data of a transmission path between the wireless relay station and a base station that is a candidate for connection of the wireless relay station via the antenna;
Based on the position information of the radio relay station acquired by the acquisition unit and the position information of the plurality of base stations stored by the storage unit, the distance from the plurality of base stations to the radio relay station A predetermined number of base stations in ascending order are selected as the connection candidate base stations, and based on the radio wave propagation environment data acquired by the receiver, the connection candidate base stations select a connection base station of a wireless relay station, seen including a processing unit for controlling the directivity of the antenna in the direction of the connected base station,
The processing unit performs control to form a null point of the antenna in the direction of the connection candidate base station that has not been selected,
The receiving unit scans the antenna to acquire radio wave propagation environment data when communication is not performed,
The processing unit performs control to form a null point of the antenna in the direction in which the interference wave is detected when the interference wave is detected from the acquired radio wave propagation environment data. A wireless relay station.

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