JP6498241B2 - Wireless communication apparatus and moving body - Google Patents

Description

  The present invention relates to a wireless communication device and a mobile object including the wireless communication device.

  Conventionally, in-vehicle antennas for wireless communication devices such as mobile communication and broadcast reception mounted on a moving body such as a movable vehicle (automobile), an omnidirectional antenna (hereinafter referred to as an “omni antenna”) such as a sleeve antenna. (Refer to Patent Documents 1 and 2, for example).

  The omni antenna is frequently used because the direction of a mobile unit equipped with a wireless communication device and the direction of reception (transmission) of radio waves such as mobile communication and broadcast reception change, and the mobile unit is the center. This is due to the fact that the distribution of the arrival direction (radiation direction) of radio waves of mobile communication is almost uniform in all directions so that it can be approximated by the Jakes model. Further, for the same reason, spatial diversity for improving communication quality can be achieved at a short distance compared to a base station having a fixed arrangement such as a macro cell base station. For this reason, the in-vehicle antenna mounted on the moving body is mainly a space diversity configuration in which a plurality of omni antennas are provided as element antennas.

  However, when trying to use Doppler diversity for improving communication quality associated with movement of a mobile object equipped with a wireless communication device using the conventional omni antenna, the movement of the mobile object equipped with the wireless communication device is accompanied. There is a possibility that the Doppler frequency shift in the generated reception signal of the wireless communication spreads (for example, spreads twice as large as the maximum Doppler frequency), and the wireless communication throughput decreases.

A wireless communication apparatus according to an aspect of the present invention is a wireless communication apparatus that can be attached to a moving body, and has directivity in a plurality of different directions with respect to a main moving direction in which the moving body mainly moves. Based on a plurality of directional antennas, a frequency shift detection unit that detects a plurality of Doppler frequency shifts corresponding to each of the plurality of directional antennas when the mobile body moves, and a detection result of the plurality of Doppler frequency shifts, A plurality of signal processing units for processing at least one of a reception signal and a transmission signal via each of the plurality of directional antennas so as to compensate for the Doppler frequency shift, and the plurality of directional antennas are It is a thin antenna installed on the outer surface of the moving body.
A wireless communication device according to another aspect of the present invention is a wireless communication device that can be attached to a moving body, and has directivity in a plurality of different directions with respect to a main moving direction in which the moving body mainly moves. A plurality of directional antennas, a frequency shift detection unit that detects a plurality of Doppler frequency shifts corresponding to each of the plurality of directional antennas when the mobile body moves, and a detection result of the plurality of Doppler frequency shifts A plurality of signal processing units for processing at least one of a reception signal and a transmission signal through each of the plurality of directional antennas so as to compensate for the Doppler frequency shift, and the plurality of directional antennas are It is the thin-shaped antenna installed in the upper surface part of the roof of the said mobile body.
In the wireless communication apparatus, the plurality of directional antennas may be installed at the same height of the moving body.
In the wireless communication apparatus, the plurality of directional antennas may be either a film type array antenna or a patch antenna.
Further, in the wireless communication device, the plurality of directional antennas are directed in a direction opposite to the main moving direction of the moving body and the forward directional antenna having directivity facing the moving direction of the moving body. A rear directional antenna having directivity, a first lateral directional antenna having directivity on one side in a direction crossing a main movement direction of the mobile body, and the other side of the mobile body And a second side directional antenna having directivity.
In the wireless communication device, the front directional antenna and the rear directional antenna, or the first side directional antenna and the second directional antenna are selected so as to select a base station device having the highest reception strength. It further comprises switching means for switching to any one of the side directional antennas, and the frequency shift detector is configured to move the front directional antenna and the rear directional antenna or the first directional antenna when the moving body moves. Detecting two Doppler frequency shifts corresponding to any one of the one lateral directional antenna and the second lateral directional antenna whose beams are switched by the switching means; Based on the detection result of the Doppler frequency shift corresponding to the forward directional antenna, the forward directivity is compensated to compensate for the Doppler frequency shift. A signal processing unit for a front directional antenna that processes at least one of a reception signal and a transmission signal via the antenna, and the Doppler frequency shift compensation based on the detection result of the Doppler frequency shift corresponding to the rear directional antenna A signal processing unit for a backward directional antenna that processes at least one of a reception signal and a transmission signal via the backward directional antenna, and a Doppler frequency shift corresponding to the first lateral directional antenna. A signal for the first lateral directional antenna that processes at least one of the reception signal and the transmission signal through the first lateral directional antenna so as to compensate for the Doppler frequency shift based on the detection result. Based on the detection result of the processing unit and the Doppler frequency shift corresponding to the second lateral directional antenna, the Doppler A signal processing unit for a second side directional antenna that processes at least one of a reception signal and a transmission signal via the second side directional antenna so as to compensate for a frequency shift May be.
In the wireless communication apparatus, the signal processing unit converts at least one frequency of the reception signal and the transmission signal so as to compensate for the Doppler frequency shift based on the detection result of the Doppler frequency shift. Also good.
The wireless communication apparatus may be a mobile base station that performs backhaul wireless communication with a fixedly arranged base station of the mobile communication system.
The wireless communication apparatus may be a mobile station that performs wireless communication with a base station of a mobile communication system.
The wireless communication apparatus may be a broadcast receiving apparatus that receives broadcast radio waves transmitted from a broadcast transmitting station.
In the wireless communication apparatus, the moving body may be a car including a passenger car, a bus, a truck, or a motorcycle, a railway vehicle traveling on a track, an aircraft, or a ship.

  The mobile body which concerns on the other aspect of this invention is a mobile body provided with either of the said radio | wireless communication apparatuses. The mobile body may be a car including a passenger car, a bus, a truck, or a motorcycle, a railway vehicle that travels on a track, an aircraft, or a ship.

  According to the present invention, it is possible to improve communication quality using Doppler diversity while suppressing a decrease in throughput of wireless communication.

Explanatory drawing which shows an example of the communication system containing the radio | wireless communication apparatus (mobile base station) incorporated in the mobile body (automobile) which concerns on one Embodiment of this invention. Explanatory drawing which shows the other example of the communication system which concerns on embodiment of this invention. Explanatory drawing which shows the further another example of the communication system which concerns on embodiment of this invention. The block diagram which shows the example of 1 structure of the base station apparatus of the moving cell base station which concerns on this embodiment. The block diagram which shows the other structural example of the base station apparatus of the moving cell base station which concerns on this embodiment. The block diagram which shows the further another structural example of the base station apparatus of the moving cell base station which concerns on this embodiment. (A) is explanatory drawing which showed typically the distribution (arrival wave distribution) of the electromagnetic wave from the fixed base station which has arrived at the radio | wireless communication apparatus incorporated in the moving vehicle which concerns on a comparative example. (B) And (c) is explanatory drawing which shows an example of the frequency distribution of the received signal received by an omni antenna during the stop and movement of the motor vehicle in which the said radio | wireless communication apparatus was respectively integrated. (A) is explanatory drawing which showed typically the distribution (arrival wave distribution) of the electromagnetic wave from the fixed base station which has arrived at the moving cell base station incorporated in the moving vehicle which concerns on this embodiment. (B) is explanatory drawing which shows an example of the frequency distribution of the received signal received by a front directional antenna and a backward directional antenna during the movement of the moving cell base station. The block diagram which shows one structural example of the 1st radio | wireless communication part in the base station apparatus of the moving cell base station which has a Doppler diversity function which concerns on this embodiment. The block diagram which shows the structural example of the 2nd radio | wireless communication part in the base station apparatus of the moving cell base station which concerns on this embodiment. (A) is explanatory drawing which showed typically the distribution (arrival wave distribution) of the electromagnetic wave from the fixed base station which has arrived at the moving cell base station built in the moving vehicle which concerns on other embodiment. (B) is explanatory drawing which shows an example of the frequency distribution of the received signal received by a side directional antenna during the movement of the moving cell base station. (A) is explanatory drawing which showed typically the distribution (arrival wave distribution) of the electromagnetic wave from the fixed base station which has arrived at the moving cell base station incorporated in the moving vehicle which concerns on other embodiment. (B) is explanatory drawing which shows an example of the frequency distribution of the received signal received by a front directional antenna, a back directional antenna, and a side directional antenna during the movement of the moving cell base station. The block diagram which shows the example of 1 structure of the base station apparatus of the moving cell base station incorporated in the moving vehicle which concerns on embodiment of FIG. (A) And (b) is the side view and perspective view which show one example of arrangement | positioning of the antenna in the motor vehicle in which the moving cell base station which concerns on embodiment of FIG. 12 was respectively integrated. (A) And (b) is the side view and perspective view which show the other example of arrangement | positioning of the antenna in the motor vehicle in which the moving cell base station which concerns on embodiment of FIG. 12 was each incorporated. (A) is a perspective view which shows the further example of arrangement | positioning of the antenna in the motor vehicle in which the moving cell base station which concerns on embodiment of FIG. 12 was integrated. (B) is an enlarged view of an antenna disposed on the windshield of the vehicle. An explanatory view showing an example of a film type array antenna. The block diagram which shows the other structural example of the base station apparatus of the moving cell base station integrated in the motor vehicle which is moving concerning embodiment of FIG. (A) And (b) is explanatory drawing of the directional beam formed with the base station apparatus of the moving cell base station respectively incorporated in the moving vehicle of FIG. Explanatory drawing which shows an example of the communication system containing the radio | wireless communication apparatus (mobile station) incorporated in the mobile body (automobile) which concerns on other embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 are each an explanatory diagram showing an example of a communication system including a wireless communication device (mobile base station) incorporated in a mobile body according to an embodiment of the present invention. The system of the present embodiment is a mobile type as a wireless communication device mounted on a fixed base station 20 connected to a cellular mobile communication network 10 and an automobile (passenger car, truck, bus, etc.) 40 that is a mobile body. A base station (hereinafter referred to as “moving cell base station”) 30 and a management device 60 that manages the moving cell base station 30 are provided. In addition, although this embodiment demonstrates the case where a moving body is the motor vehicle 40, the mobile body in this embodiment may be a rail vehicle, an aircraft, or a ship which drive | works on a track | line other than a motor vehicle. In the communication system of FIG. 1, the fixed base station 20 is an example of a macro cell base station, but the fixed base station 20 may be a small cell base station. The management device 60 may be configured by a computer device such as a single server, or may be configured such that computer devices such as a plurality of servers perform processing in cooperation with each other.

  In the communication system of FIG. 1, the moving cell base station 30 forms a mobile cell (hereinafter referred to as “moving cell”) 30 </ b> A that covers at least the peripheral area outside the automobile 40 and the interior of the automobile 40. A user apparatus 50 as a mobile station located in the cell 30A, a fixed base station 20, a user apparatus located in the cell 20A covered by the fixed base station 20 or another base station installed in another mobile unit Relay communication between. The moving cell 30 </ b> A may include a peripheral area outside the automobile 40 and an inner area of the automobile 40. The cell diameter of the moving cell 30A is, for example, 100 m, and may be 20 m or less to 50 m or less.

  The moving cell base station 30 includes a plurality of first antennas 311 for performing wireless communication between the base station device 300 and another moving cell base station 30 installed in the fixed base station 20 or another moving body. 312 and a second antenna 315 that performs wireless communication with the user device 50 used by a general user of mobile communication in the moving cell 30A formed by the base station device 300. The first antenna 311, 312 and the second antenna 315 are the main body of the automobile 40, for example, the front grille, the body rear part, the bumper part, the flat part of the roof, the shark antenna part at the rear of the roof in which the antenna for other uses is incorporated Or it is provided in the pillar part. The first antennas 311 and 312 and the second antenna 315 may be shared antennas.

  The first antennas 311 and 312 are a plurality of directional antennas having unidirectivity in a plurality of directions different from each other with reference to a main moving direction in which the automobile 40 mainly moves. In the illustrated example, one of the plurality of first antennas 311 and 312, one first antenna 311 is a forward directional antenna having directivity toward the front direction F that is the main movement direction of the automobile 40, and the other The first antenna 312 is a rear directional antenna having directivity in the rear direction B which is the direction opposite to the main movement direction of the automobile 40. Each of the first antennas 311 and 312 may be a planar antenna such as a patch antenna or a microstrip antenna.

  The first antennas 311 and 312 may have a beam forming function using a plurality of antenna elements. In this embodiment, an omni antenna is used as the second antenna 315. However, the second antenna 315 may be composed of a front directional antenna and a rear directional antenna, similarly to the first antenna. In this case, the second antenna 315 may have a beam forming function capable of controlling the number and direction of antenna beams.

  In FIG. 1, the base station device 300 is installed, for example, in the trunk of an automobile 40, inside the dashboard, or below the seat. The base station apparatus 300 may include a power source (battery) in its own apparatus, but may receive power from a battery on the automobile 40 side. When power is supplied from the battery on the automobile 40 side, the power supply from the battery to the base station apparatus 300 is a predetermined time (for example, 1 hour) from the stop of driving (OFF) of the automobile 40 that stops charging the battery. You may make it be stopped automatically when elapses.

  In the communication system of FIG. 1, the moving cell base station 30 may have a repeater function that functions as a radio relay station of the fixed base station 20. The moving cell base station 30 is assigned base station identification information (cell ID) that can be identified from other base stations, and can be connected to the backhaul line of the mobile communication network 10 via the fixed base station 20. It may have a function.

  In FIG. 2, the moving cell base station 30 mounted on the automobile 40 communicates with the user equipment 50 and the satellite base station 22 as a fixed base station that communicates with the ground via the satellite station (artificial satellite) 20. It is a structural example of the communication system to relay.

  3 shows a fixed base station 25 in which a moving cell base station 30 mounted on an automobile 40 communicates with the ground via a mooring balloon relay station (wireless relay station) 24 provided in the mooring balloon 23, and a user. 3 is a configuration example of a communication system that relays communication with a device 50.

4 to 6 are block diagrams each illustrating a configuration example of the base station apparatus 300 of the moving cell base station 30 according to the present embodiment.
In FIG. 4, the base station apparatus 300 of the moving cell base station 30 is configured to be installed in the automobile 40 and is installed in the fixed base station 20 or other mobile body via the first antennas 311 and 312. A first wireless communication unit 302 that performs wireless communication with the station device, a second wireless communication unit 304 that performs wireless communication with the user device 50 via the second antenna 315, and a relay control unit 306. Prepare. The relay control unit 306 forms a moving cell 30A in at least an outer peripheral area of the automobile 40, and the user apparatus 50 located in the moving cell 30A and another base station installed in the fixed base station 20 or another mobile body The first wireless communication unit 302 and the second wireless communication unit 304 are controlled so as to relay communication with the apparatus.

  The base station apparatus 300 may include a power source (battery) in its own apparatus, but may receive power from a battery 41 on the automobile 40 side as shown in FIG. In this case, the supply of power from the battery 41 to the base station apparatus is performed by turning off the key of the automobile 40 that stops charging the battery 41 so that the remaining charge capacity of the battery 41 does not become a predetermined capacity or less (driving stop). It may be controlled to automatically stop when a predetermined time (for example, 1 hour) elapses. The time until the automatic stop may be set based on the remaining charge capacity of the battery 41 or the like.

  In the moving cell base station 30, the frequency band used for wireless communication with the fixed base station 20 and the frequency band used for wireless communication with the user apparatus 50 may be different from each other. For example, the 28 GHz band, the 5 GHz band, or the 4.2 GHz band used in the fifth generation mobile communication system is used as the frequency band used for the wireless communication with the fixed base station 20, and the wireless communication with the user apparatus 50 is performed. As a frequency band used for the above, a 2.6 GHz band, a 700 MHz band, or a 2 GHz band may be used. By using different frequency bands in this way, the moving cell base station 30 can reliably perform each wireless communication while avoiding interference between the wireless communication with the fixed base station 20 and the wireless communication with the user device 50. It can be carried out.

  Also, in the base station device 300 of the moving cell base station 30, the transmission power and reception sensitivity of the first radio communication unit 302 for the fixed base station 20 are higher than the transmission power and reception sensitivity of the user device 50 for the fixed base station 20. You may comprise as follows. In this case, the moving cell base station 30 has a higher communication quality with the fixed base station 20 in the area of the cell boundary of the cell 20A of the fixed base station 20 to which the user apparatus 50 can communicate and the out-of-service area in the vicinity thereof. Communication is possible, and the moving cell 30A can be formed in the area. Accordingly, local traffic offload can be reliably performed in the cell 20A of the fixed base station 20, and the mobile communication area can be substantially expanded without increasing the number of the fixed base stations 20. Further, the moving cell base station 30 may be connected simultaneously with the plurality of fixed base stations 20, set up a plurality of lines, and increase the capacity of the line between the moving cell base station 30 and the fixed base station 20 ( (Increased line capacity between fixed base station group and moving cell base station due to line aggregation by multiple fixed base station sites).

  In addition, even in a parking lot on a mountain trail or trailhead where the radio field intensity from the fixed base station 20 is weak, it is mounted on a vehicle 40 traveling on the mountain trail or a vehicle 40 parked in the trailer parking lot. The moving cell base station 30 can form a moving cell 30A around the automobile 40. Therefore, a user along the mountain trail, a parking lot at the mountain entrance, and a user in the vicinity thereof can use the mobile communication service via the moving cell base station 30.

  The relay control unit 306 may control the base station device 300 so as to function as a wireless relay station (repeater). Further, the relay control unit 306 is assigned with base station identification information (cell ID) that can be distinguished from other base stations, and controls to connect to the backhaul line of the mobile communication network 10 via the fixed base station 20. It may be a thing.

  Further, the relay control unit 306 performs a first handover process associated with the movement of the own station 30 relative to the fixed base station 20 and a second handover process associated with the relative movement between the own station 30 and the user apparatus 50 as follows: May be configured to be capable of simultaneous parallel processing. For example, the relay control unit 306 performs a handover process in which the local station 30 continues to connect to the mobile communication network 10 when the local station 30 moves across the cells 20A of the plurality of fixed base stations 20, and the local station When the user apparatus 50 moves relative to 30, the user apparatus 50 may be controlled to perform a handover process for continuing the connection with the mobile communication network 10. By such a double handover process, even when the moving cell 30A is formed along with the movement of the own station 30, the connection of the user apparatus 50 residing in the moving cell 30A to the mobile communication network 10 is disconnected. Can be avoided.

  Further, the relay control unit 306 may control the transmission power when the mobile station 30 is turned ON / OFF or the mobile cell is formed. This control is formed by, for example, the position information of the own station 30, the attitude information of the own station 30, the moving speed of the own station 30, and other base station devices provided in the automobile 40 located around the own station 30. You may perform based on the condition of a surrounding cell, and at least one of the control information from the outside. For example, the relay control unit 306 may control ON / OFF of the moving cell formation or transmission power at the time of moving cell formation based on the control information received from the management device 60 via the mobile communication network 10. Here, the position information of the own station 30, the attitude information of the own station 30, the moving speed of the own station 30, and the like are obtained from the GPS receiver and the direction sensor provided in the base station device 300 of the own station 30 and the main body of the automobile 40. The determination can be made based on the output or based on the location registration information of the own station 30.

  Further, in the communication system according to the present embodiment, the same frequency is not adjacent to the frequency used for the wireless communication with the user apparatus 50 on the moving route (for example, road) of the automobile 40 based on the arrangement of the fixed base station 20 or the like. A plurality of zones may be set as described above. The size of each zone is set to such a size that a plurality of moving cells can be arranged so as not to overlap each other. The length of each zone is, for example, 50 m to 1 km. Then, with such a plurality of zones set, the relay control unit 306 performs wireless communication with the user apparatus 50 for each of the plurality of zones using the frequency set in the zone where the local station 30 is located. You may control to do. For example, when the relay control unit 306 enters the automobile 40 in any one of the plurality of zones, the relay control unit 306 performs wireless communication with the user device 50 using a predetermined frequency set in the zone in which the automobile 40 is entered. Control to do. In this way, by performing wireless communication with the user apparatus 50 using a predetermined frequency for each zone, each zone can be regarded as a quasi-static cell, and the frequency of handover processing by the user apparatus 50 can be reduced. The burden can be suppressed.

  Further, the second antenna 370 of the moving cell base station 30 may have a beamforming function, and the relay control unit 306 may control at least one of the direction and the number of beams formed by the second antenna 370. For example, the control of the beam direction and the like is performed on a moving body such as a position information of the own station 30, an attitude information of the own station 30, a moving speed of the own station 30, and an automobile located around the own station 30. Can be performed based on at least one of the status of neighboring cells formed by the base station apparatus and control information from the outside. Here, the position information of the own station 30, the attitude information of the own station 30, the moving speed of the own station 30, and the like are obtained from the GPS receiver and the direction sensor provided in the base station device 300 of the own station 30 and the main body of the automobile 40. The determination can be made based on the output or based on the location registration information of the own station 30. In particular, the relay control unit 306 forms a beam in different directions in cooperation between the own station 30 and other moving cell base stations mounted on other nearby vehicles in a parking lot or the like. The station 30 and other moving cell base stations may be controlled to form one cell. The cooperative control by the plurality of moving cell base stations can be performed based on control information received via the mobile communication network 10 from the management device 60 that manages the moving cell base stations, for example. This control information is determined based on, for example, position information and attitude information of each moving cell base station.

  Also, as shown in FIG. 6, the base station apparatus 300 includes a data processing unit 310 that processes data transmitted to and received from the user apparatus 50, the fixed base station 20, or a surrounding mobile base station apparatus, The processing unit 310 may be used for various purposes to cause the moving cell base station 30 to function as a movable local data center.

  For example, the data processing unit 310 provides information to be provided to a mobile base station device such as the user device 50, the fixed base station 20, or a surrounding vehicle, and data on area information related to an area where the vehicle 40 including the own station 30 is located. , Map information data of the area, navigation data of the area, automatic driving data of the moving body of the car 40 in the area, image data of still images or moving images taken by the car 40, moving objects such as surrounding cars Image data of still images or moving images taken in the mobile station, image data of still images or moving images taken by a base station device provided in a moving body such as a surrounding automobile, and the user device 50 connected to the own station 30 At least one of the image data of the still image or the moving image captured in step S <b> 1 may be generated, stored in the storage unit 308, or read from the storage unit 308. In this case, the relay control unit 306 receives the at least one data autonomously in response to a request from the user device 50, the fixed base station 20, or a base station device of a surrounding mobile body, the user device 50, the fixed base station. Control is performed so as to transmit or receive data to or from a mobile base station device such as 20 or a nearby automobile.

  By having the data processing unit 310 and the relay control unit 306 configured as described above, the moving cell base station 30 can, for example, a user who is in the moving cell 30A in the area information downloaded from the server on the mobile communication network 10 side. The information may be transmitted to the device 50, or the area information uniquely acquired by the user device 50 or the automobile 40 main body may be received and stored in the local station 30 or uploaded to a server on the mobile communication network 10 side. In addition, the moving cell base station 30 is a vehicle 40 main body that functions as the user device 50 located in the moving cell 30A using the detailed navigation data and automatic driving data in the surrounding area downloaded from the server on the mobile communication network 10 side. It may be transmitted to a navigation system or an automatic driving system. In addition, the moving cell base station 30 receives and stores in the own station 30 information such as navigation data and autonomous road data for the self-driving data that the user device 50 or the car 40 itself has independently acquired, Based on the received information, navigation data and automatic driving data are generated, or the received information or the generated navigation data and automatic driving data are uploaded to a server on the mobile communication network 10 side. Also good.

  The data is data to be transported through the movement of the automobile 40 equipped with the station 30 (for example, large-capacity book or movie data purchased on the Internet that does not require urgency). May be. In this case, the data processing unit 310 stores and reads the data to be transported to and from the storage unit 308 to be transmitted / received to / from the mobile device such as the user device 50, the fixed base station 20, or a surrounding automobile. In addition, the relay control unit 306 receives the data to be transported autonomously in response to a request from the user device 50, the fixed base station 20, or a base station device of a surrounding mobile body, or the user device 50, the fixed base station 20 or In response to a request from the user apparatus 50, the fixed base station 20, or a peripheral mobile base station apparatus after the automobile 40 including the own station 30 has moved to a predetermined position after being received from the peripheral mobile base station apparatus. Or autonomously, control is performed such that data to be transported is transmitted to the user apparatus 50, the fixed base station 20, or a base station apparatus of a surrounding mobile body. With the above control, for example, large-capacity books and movie data that do not have urgency can be transported to a predetermined transport destination without going through the mobile communication network 10, thereby suppressing the load on the mobile communication network 10. Can do.

  In addition, the transportation of the data may be performed by a single automobile 40 equipped with the moving cell base station 30 or a plurality of automobiles 40 equipped with the moving cell base station 30 may sequentially transfer the transportation. You may make it perform. Data transfer between the plurality of automobiles 40 may be performed by direct communication between the moving cell base stations 30 mounted on each of the plurality of automobiles 40 or may be performed by communication via the fixed base station 20.

  Also, in the base station apparatus 300 of the moving cell base station 30 shown in FIGS. 4 to 6, the first radio communication unit 302 is configured with a terminal apparatus (including a control apparatus and a data modulation / demodulation apparatus) paired with the fixed base station 20. The second wireless communication unit 304 may be configured by a base station device similar to the base station device of the fixed base station 20.

  Next, the Doppler diversity function of the moving cell base station 30 mounted on the automobile 40 in the communication system having the above configuration will be described.

  FIG. 7A is an explanatory diagram schematically showing the distribution of radio waves (arrival wave distribution) from a fixed base station arriving at a wireless communication device incorporated in a moving automobile 40 according to a comparative example. . FIGS. 7B and 7C respectively illustrate examples of frequency distributions of received signals received by the omni antenna (omni antenna) 319 while the automobile incorporating the wireless communication device is stopped and moved. FIG. A circle 900 indicated by a broken line in FIG. 7A is used to approximate the radio propagation in which the radio wave transmitted from the fixed base station reaches the radio communication device of the automobile 40 using the Jakes model of the classical mobile communication propagation theory. It is a scattering ring. Black dots 909 distributed on the scattering ring 900 are scattering points that emit radio waves received by the omni antenna 319 of the wireless communication device of the automobile 40. The omni antenna 319 has a circular omnidirectional characteristic 319A centered on the antenna in the horizontal plane, and thus receives radio waves arriving from all scattering points 909 on the scattering ring 900. In addition, the intensity of radio waves coming from the scattering points 909 in all directions on the scattering ring 900 is substantially uniform. The phenomenon that the intensity of radio waves arriving from all directions becomes almost uniform, such as the incoming wave distribution that can be approximated by the Jakes model, has been confirmed not only in urban areas where there are many buildings such as buildings that reflect and scatter radio waves, but also in the suburbs. Yes.

  Conventionally, an omni antenna such as a sleeve antenna has been frequently used in an in-vehicle antenna such as a car phone. This is due to the fact that the incoming wave distribution centered on a moving body such as an automobile equipped with a wireless communication device is substantially uniform from all directions based on the Jakes model as described above. Further, for the same reason, spatial diversity for improving communication quality can be achieved at a short distance compared to a base station having a fixed arrangement such as a macro cell base station. For this reason, in a vehicle-mounted antenna mounted on a moving body such as a conventional automobile, a space diversity configuration in which a plurality of omni antennas are provided as element antennas is the mainstream. However, as shown below, when an omni-antenna is used, the frequency spread ΔfD due to the frequency shift due to the Doppler effect (hereinafter referred to as “Doppler frequency shift”) becomes twice the maximum Doppler frequency shift fD. There is a problem that the throughput may be reduced, or the calculation of the reception circuit and the reception signal may be complicated.

  For example, when the automobile 40 is stopped, the frequency of the received signal 910 received when the radio wave transmitted from the fixed base station reaches the omni antenna 319 via each scattering point 909 is shown in FIG. As shown in FIG. 4, the center frequency fC of the radio wave transmitted from the fixed base station is obtained. Further, during the movement in which the automobile 40 is moving in the forward direction F, as shown in FIG. 7C, due to the Doppler effect, the scattering point located in the forward direction F, which is the moving direction of the automobile 40, moves from the scattering point. The frequency of the received radio wave signal is shifted by + fD, and the frequency of the received radio wave signal toward the automobile 40 from the scattering point located in the backward direction opposite to the moving direction of the automobile 40 is shifted by -fD. As a result, the spread ΔfD of the frequency fC due to the Doppler frequency shift of the received signal 919 received by the omni antenna 319 becomes twice (2fD) the maximum Doppler frequency shift fD.

Further, since scattering at each scattering point 909 on the scattering ring 900 of the Jakes model is a different scattering process, radio waves scattered at a plurality of scattering points 909 are individually received .

  Therefore, in this embodiment, in order to solve the above-described problem, attention is paid to the fact that scattering at each scattering point 909 on the scattering ring 900 of the Jakes model is a different scattering process, and scattering is performed at a plurality of different scattering points. By adopting a configuration having a plurality of individual reception systems (hereinafter referred to as “diversity branches”) to which a unidirectional antenna is assigned for each Doppler frequency shift of the received radio wave, the throughput due to the spread ΔfD of the frequency fC due to the Doppler frequency shift While suppressing the reduction, the circuit scale is small and an effective diversity effect is obtained. In particular, in the present embodiment, the Doppler frequency shift of the received signal received by each diversity branch is a Doppler frequency shift shifted in one direction (plus direction or minus direction) from the center frequency fC of the radio wave transmitted from the fixed base station. Since each diversity branch is configured as described above, in addition to the diversity effect, the demodulation process of the reception signal is easy, and the effect that the reception circuit scale is small and high demodulation performance can be obtained.

  FIG. 8A schematically illustrates the distribution of radio waves (arrival wave distribution) from the fixed base station 20 arriving at the moving cell base station 30 incorporated in the moving automobile according to the present embodiment. FIG. FIG. 8B is an explanatory diagram showing an example of the frequency distribution of the received signals 911 and 912 received by the front directional antenna 311 and the rear directional antenna 312 while the moving cell base station 30 is moving. .

  In the embodiment of FIG. 8, according to the above-mentioned Jakes model, the received signal of the incoming wave arriving from the front direction F of the automobile 40 equipped with the moving moving cell base station 30 is shifted to the higher frequency due to the Doppler effect. . On the contrary, the received signal of the incoming wave coming from the rear direction of the automobile 40 is shifted to a lower frequency due to the Doppler effect. The unidirectional antennas 311 and 312, which are spatial filters that exclusively receive the incoming waves from the forward direction and the backward direction, are respectively installed before and after the automobile 40 to form a diversity branch. Since the frequency spread ΔfD due to the Doppler frequency shift fD of the incoming wave received at each diversity branch is narrower than the above-described comparative example as shown in FIG. 8B, the demodulation process of the received signal is easy. The circuit scale is small and high demodulation performance can be obtained, so that reception characteristics are improved.

  In the example of FIG. 8, the case of receiving radio waves from the fixed base station 20 is shown. However, since the antennas 311 and 312 have a transmission / reception correlation, the case of transmitting radio waves to the fixed base station 20 is also possible. There is a similar effect.

FIG. 9 is a block diagram illustrating a configuration example of the first wireless communication unit 302 in the base station apparatus 300 of the moving cell base station 30 having the Doppler diversity function according to the present embodiment.
In FIG. 9, the first wireless communication unit 302 includes a first high-frequency signal processing unit 320A connected to the front directional antenna 311, a second high-frequency signal processing unit 320B connected to the rear directional antenna 312, and a base And a band processing unit 326. The first high-frequency signal processing unit 320A and the second high-frequency signal processing unit 320B include a duplexer (DUP) 321A, B, a reception power amplifier 322A, B, and a frequency shift detection unit 323A, B, respectively. Transmission power amplifiers 324A, B and frequency converters 325A, B are provided.

  Each of the frequency shift detection units 323A and 323 detects a Doppler frequency shift fD corresponding to the front directional antenna 311 and the rear directional antenna 312 when the automobile 40 moves. The detection of the Doppler frequency shift fD may be performed based on the reception result of the cell reference signal received from the fixed base station 20.

  Further, the frequency conversion units 325A and 325B each receive signals via the front directional antenna 311 and the rear directional antenna 312 so as to compensate the Doppler frequency shift fD based on the detection result of the Doppler frequency shift fD. And functions as a signal processing unit for processing the transmission signal. For example, the frequency converters 325A and 325B convert the frequencies of the reception signal and the transmission signal so as to compensate for the Doppler frequency shift fD based on the detection result of the Doppler frequency shift fD.

  In this example, the frequency conversion unit 325A uses the frequency fR (= fC + fD) of the reception signal received by the forward directional antenna 311 and amplified by the reception power amplifier 322A based on the detection result of the Doppler frequency shift fD as the original frequency. Shift conversion to fC is performed, and an analog reception signal having a high frequency fC is converted into a digital reception signal R having a predetermined intermediate frequency and output to the baseband processing unit 326. Also, the frequency conversion unit 325A converts the intermediate frequency digital transmission signal T received from the baseband processing unit 326 into an analog transmission signal of the high frequency fC, and further, based on the detection result of the Doppler frequency shift fD. The frequency fC of the transmission signal is shift-converted to the frequency fT (= fC−fD) and output to the transmission power amplifier 324A.

  Further, in this example, the frequency conversion unit 325B, based on the detection result of the Doppler frequency shift fD, receives the frequency fR (= fC−fD) of the reception signal received by the backward directivity antenna 312 and amplified by the reception power amplifier 322B. Is converted to the original frequency fC, and an analog reception signal having a high frequency fC is converted into a digital reception signal R having a predetermined intermediate frequency and output to the baseband processing unit 326. Further, the frequency conversion unit 325B converts the intermediate frequency digital transmission signal T received from the baseband processing unit 326 into an analog transmission signal of the high frequency fC, and further, based on the detection result of the Doppler frequency shift fD. The frequency fC of the transmission signal is shift-converted to the frequency fT (= fC + fD) and output to the transmission power amplifier 324B.

  Note that the frequency conversion based on the detection result of the Doppler frequency shift fD may be performed on one of the reception signal and the transmission signal.

  The baseband processing unit 326 generates reception target data from the digital reception signal R received from the first high-frequency signal processing unit 320A and the second high-frequency signal processing unit 320B, or generates first data from the transmission target control data. Various processes for generating a digital transmission signal T to be transmitted to the high-frequency signal processing unit 320A and the second high-frequency signal processing unit 320B are performed. For example, the baseband processing unit 326 includes a serial / parallel conversion unit (S / P), a parallel / serial conversion unit (P / S), a digital modulation unit, a digital demodulation unit, and the like. In addition, in the case of transmitting and receiving by orthogonal frequency division multiplexing (OFDM), the baseband processing unit 326 further includes a guard period (GI) removal unit, a digital Fourier transform (DFT) unit, a guard period ( GI) An insertion part, a digital inverse Fourier transform (IDFT) part, etc. are provided. Here, the modulation scheme and the demodulation scheme in the baseband processing unit 326 are not limited to specific ones.

  Further, the transmission method by the first wireless communication unit 302 may be a multicarrier transmission method or a single carrier transmission method.

FIG. 10 is a block diagram illustrating a configuration example of the second wireless communication unit 304 in the base station apparatus 300 of the moving cell base station 30 having the Doppler diversity function according to the present embodiment.
In FIG. 10, the second wireless communication unit 304 includes a high-frequency signal processing unit 340 and a baseband processing unit 346 connected to the second antenna 315. The high-frequency signal processing unit 340 includes a DUP (Duplexer: duplexer) 341, a reception power amplifier 342, a transmission power amplifier 344, and a frequency conversion unit 345.

  Note that the example of the second wireless communication unit 304 in FIG. 10 does not include a frequency shift detection unit that detects the Doppler frequency shift fD, but includes a front directional antenna and a rear directional antenna as the second antenna 315. The first wireless communication unit 302 includes a frequency shift detection unit and a frequency conversion unit that detect a Doppler frequency shift fD corresponding to each antenna, and a forward directional antenna and a rear side so as to compensate the Doppler frequency shift fD. You may process the received signal and transmission signal via each directional antenna.

  As described above, according to the present embodiment, the moving cell base station 30 mounted on the automobile can reduce the price and improve the communication quality by using Doppler diversity while suppressing a decrease in the throughput of wireless communication. be able to.

  FIG. 11A schematically shows the distribution of radio waves (arrival wave distribution) from a fixed base station arriving at a moving cell base station 30 incorporated in a moving automobile 40 according to another embodiment. It is explanatory drawing. FIG. 11B is an explanatory diagram showing an example of a frequency distribution of received signals received by the side directivity antennas 313 and 314 while the moving cell base station 30 is moving.

  In the embodiment of FIG. 11, according to the Jakes model as described above, the incoming signal received from the forward direction F of the automobile 40 equipped with the moving cell base station 30 moving forward has a higher frequency due to the Doppler effect. shift. On the contrary, the received signal of the incoming wave coming from the rear direction of the automobile 40 is shifted to a lower frequency due to the Doppler effect. In the present embodiment, unidirectional side directivity antennas 313 and 314, which are spatial filters that exclusively receive incoming waves from the left and right directions intersecting these forward and rearward directions, are installed in the automobile 40, respectively. Diversity branch. Since the frequency spread ΔfD due to the Doppler frequency shift fD of the incoming wave received at each diversity branch is narrower than the above-described comparative example as shown in FIG. 11B, the demodulation process of the received signal is easy. The circuit scale is small and high demodulation performance can be obtained, so that reception characteristics are improved. Here, the right side directional antenna 313 corresponds to the first side directional antenna with respect to the traveling direction F of the automobile, and the left side directional antenna 314 serves as the second side directional antenna. Equivalent to.

  In the example of FIG. 11, the case of receiving radio waves from the fixed base station 20 is shown. However, since the antennas 313 and 314 have a transmission / reception correlation, the case of transmitting radio waves to the fixed base station 20 is also possible. There is a similar effect.

  FIG. 12A schematically shows the distribution of radio waves (arrival wave distribution) from a fixed base station arriving at a moving cell base station 30 incorporated in a moving automobile 40 according to another embodiment. FIG. FIG. 12B shows an example of the frequency distribution of received signals received by the front directional antenna 311, the rear directional antenna 312 and the side directional antennas 313 and 314 while the moving cell base station 30 is moving. It is explanatory drawing shown.

  In the embodiment of FIG. 12, unidirectional antennas 313 and 314, which are spatial filters that exclusively receive incoming waves from the front direction, the rear direction, and the left and right directions, are respectively installed in the automobile 40 to form a diversity branch. Since the frequency spread ΔfD due to the Doppler frequency shift fD of the incoming wave received at each diversity branch is narrower than the above-described comparative example as shown in FIG. 12B, the demodulation process of the received signal is easy. The circuit scale is small and high demodulation performance can be obtained, so that reception characteristics are improved.

  In the example of FIG. 12, the case of receiving radio waves from the fixed base station 20 is shown. However, since the antennas 313 and 314 have a transmission / reception correlation, the case of transmitting radio waves to the fixed base station 20 is also possible. There is a similar effect.

  FIG. 13 is a block diagram illustrating a configuration example of the base station apparatus 300 of the moving cell base station 30 incorporated in the moving automobile 40 according to the embodiment of FIG. In FIG. 13, the description of the same configuration as that of the base station apparatus 300 described with reference to FIGS.

  In FIG. 13, the first wireless communication unit 302 of the base station apparatus 300 includes four directional antennas including a front directional antenna 311, a rear directional antenna 312, a right side directional antenna 313, and a left side directional antenna 314. Is connected. The first wireless communication unit 302 includes a first high-frequency signal processing unit 320A connected to the front directional antenna 311 and a second high-frequency signal processing unit 320B connected to the rear directional antenna 312. A third high-frequency signal processing unit connected to the right-side directional antenna 313 and a fourth high-frequency signal processing unit connected to the left-side directional antenna 314 are provided (see FIG. 9).

FIGS. 14A and 14B are a side view and a perspective view, respectively, showing an arrangement example of the antennas 311 to 314 in the automobile (truck) 40 in which the moving cell base station 30 according to the embodiment of FIG. 12 is incorporated. .
14A and 14B, a thin front directional antenna 311 and a rear directional antenna 312 are respectively provided on the front surface 43, the rear surface 44, and the left side surface 46, which are the outer surface portions of the container of the automobile (truck) 40. Side directional antennas 314 are installed. A thin side directional antenna 313 is provided on the right side surface 45 of the container. The front directional antenna 311, the rear directional antenna 312, and the side directional antennas 313 and 314 are installed to have substantially the same height. The antennas 311 to 314 arranged in this way have directivity perpendicular to the main plane, and as shown in FIG. Beams 311A, 312A, 313A, and 314A having the same height are formed. Further, since the antennas 311 to 314 arranged on the outer surface of the container of the automobile (truck) 40 have a thin shape, the influence on the design, vehicle width, and vehicle length of the automobile 40 is small.

  The directional antennas 311 to 314 arranged in the automobile 40 may be patch antennas, for example. The patch antenna is a high-gain antenna having a thin structure in which a dielectric is sandwiched between both sides by a metal plate and having directivity in a direction perpendicular to the main plane, and is suitable for Doppler diversity.

FIGS. 15A and 15B are a side view and a perspective view, respectively, showing another arrangement example of the antennas 311 to 314 in the automobile 40 in which the moving cell base station 30 according to the embodiment of FIG. 12 is incorporated.
15A and 15B, a front directional antenna 311, a rear directional antenna 312, a right directional antenna 313, and a left side are provided on an upper surface 42 such as a roof top of a container roof of an automobile (truck) 40. A directional antenna 314 is disposed. Thus, by arranging the antennas 311 to 314 on the upper surface 42 of the roof top of the container roof, the height of each directional antenna can be easily adjusted. Further, the antennas 311 to 314 arranged in this way have directivity from the end face in the lateral direction (lateral direction, horizontal direction), as shown in FIG. Directive beams 311A, 312A, 313A, and 314A having the same height are formed on the right side and the left side, respectively. In addition, since the antennas 311 to 314 have a thin shape, the influence on the design of the automobile 40 and the vehicle height is small.

  FIG. 16A is a perspective view showing still another arrangement example of the antennas 311 to 314 in the automobile 40 in which the moving cell base station 30 according to the embodiment of FIG. 12 is incorporated, and FIG. It is an enlarged view of the antenna 316 arrange | positioned at the windshield.

  In FIG. 16A, a front antenna 316 made of a film-type array antenna is attached to the front glass of the front surface 43 that is the outer surface portion around the automobile 40, and from the film-type array antenna to the left window glass of the left side surface 46. A left side antenna 319 is attached. Further, a rear antenna 317 and a right side antenna 318 made of a film-type array antenna are attached to the rear glass and the right window glass on the rear surface of the automobile 40, respectively.

  The film type array antenna used for the antennas 316 to 319 has directivity from each of the two side end faces in the lateral direction (lateral direction, horizontal direction). Accordingly, as shown in FIG. 16A, the front antenna 316 and the rear antenna 317 form directional beams 316A and 317A on the right side and the left side, respectively, with respect to the main moving direction (front) F of the automobile 40. The directional beams 318A and 319A are formed on the front side and the rear side of the automobile 40 by the right side antenna 318 and the left side antenna 319, respectively.

  Moreover, since the film type array antenna used for the antennas 316 to 319 is formed transparently, the influence on the vehicle design is small and the vehicle design can be maintained. Further, the installation heights of the antennas 316 to 319 made of a film type array antenna are pasted so as to be substantially the same. Further, since the film type array antenna is a narrow beam antenna, it is suitable as an in-vehicle antenna used for Doppler diversity.

  Further, as shown in FIG. 16B, a front antenna 316 made of a film-type array antenna is pasted on the right side of the front glass of the front F of the automobile 40. As described above, the film-type array antenna is transparent. Therefore, it does not disturb the driver's view. The position where the front antenna 316 of the film type array antenna is pasted is not limited to the right side of the windshield with respect to the traveling direction F of the automobile 40, but may be any position on the left side, above or below the windshield.

  FIG. 17 is an explanatory diagram showing an example of a film type array antenna 330 that can be used as the antennas 316 to 319 of FIG. In FIG. 17, a film-type array antenna 330 is composed of a plurality of antenna elements 331 arranged on a surface in parallel with each other, and the interval between adjacent antenna elements 331 is λ / 2 (λ: transmission / reception by an antenna). Radio wave). For example, when the frequency of the radio wave is 28 [GHz], λ = 1 [cm] and the interval between the antenna elements 331 is 5 [mm].

  Each antenna element 331 of the film type array antenna 330 may be a balanced feed type antenna. For example, each antenna element 331 may be a dipole antenna or a loop antenna.

  FIG. 18 is a block diagram illustrating another configuration example of the base station apparatus of the moving cell base station incorporated in the moving vehicle according to the embodiment of FIG. The base station apparatus of the moving cell base station in the configuration example of FIG. 18 switches between a beam formed by a directional antenna in the front-rear direction and a beam formed by a directional antenna in the left-right direction based on the reception strength of the antenna. It is configured to switch at.

  In FIG. 18, the base station apparatus 300 is provided with an antenna switching unit 309 as switching means. The front directional antenna 311, the rear directional antenna 312, the right side directional antenna 313, and the left side directional antenna 314 are connected to the first wireless communication unit 302 via the antenna switching unit 309. The antenna switching unit 309 connects either the front directional antenna 311 and the rear directional antenna 312 or the side directional antennas 313 and 314 to the first wireless communication unit 302 based on the reception strength of the antenna. It is supposed to switch the switch. By using a unidirectional antenna, the base station with the highest reception strength can be selected by switching between the beam formed by the directional antenna in the front-rear direction and the beam formed by the directional antenna in the left-right direction. You can choose.

  In the configuration example of FIG. 18, the right-side directional antenna 313 is connected to the duplexer 321A of the first high-frequency signal processing unit 320A via the antenna switching unit 309, and the left-side directional antenna 314 is connected to the antenna switching unit 309. And is connected to the duplexer 321B of the second high-frequency signal processing unit 320B (see FIG. 9). The first wireless communication unit 302 includes the first high-frequency signal processing unit 320A connected to the front directional antenna 311 and the second high-frequency signal processing unit 320B connected to the rear directional antenna 312. A third high frequency signal processing unit connected to the right side directional antenna 313 and a fourth high frequency signal processing unit connected to the left side directional antenna 314 may be provided.

  The antenna switching unit 309 transmits signals received by the front directional antenna 311, the rear directional antenna 312, and the side directional antennas 313 and 314 to the first wireless communication unit 302. The first wireless communication unit 302 that has received the signal performs the processing described with reference to FIG. 9 and transmits the received signal R to the relay control unit 306. The relay control unit 306 transmits the received signal R to the data processing unit 310. The data processing unit 310 compares the received signal R of the signal received by the front directional antenna 311 and the rear directional antenna 312 with the received signal R of the signal received by the side directional antennas 313 and 314.

  When the strength of the reception signal R of the front directional antenna 311 and the rear directional antenna 312 is higher than the strength of the reception signal R of the side directional antennas 313 and 314, the data processing unit 310 has the front directional antenna 311. And a control signal for switching the backward directional antenna 312 to be connected to the first wireless communication unit 302 is transmitted to the antenna switching unit 309. Based on this control signal, the antenna switching unit 309 switches so that the front directional antenna 311 and the rear directional antenna 312 are connected to the first wireless communication unit 302. As a result, the front directional antenna 311 and the rear directional antenna 312 are switched so that a beam is formed forward and backward with respect to the traveling direction F of the automobile 40, and the base station having the highest reception intensity can be selected.

  On the other hand, when the received signal R of the side directional antennas 313 and 314 is higher than the received signal R of the front directional antenna 311 and the rear directional antenna 312, the data processing unit 310 has the side directional antenna 313. , 314 is transmitted to the antenna switching unit 309 to switch to connect to the first wireless communication unit 302. Based on this control signal, the antenna switching unit 309 switches the side directional antennas 313 and 314 to connect to the first wireless communication unit 302. As a result, the side directional antennas 313 and 314 are switched so as to form a beam to the left and right with respect to the traveling direction F of the automobile 40, and the base station with the highest reception intensity can be selected.

  The data processing unit 310 transmits a control signal for switching to the beam of the other antenna when the reception intensity of the reception signal R of the antenna to which the antenna switching unit 309 is connected falls below a predetermined threshold. You may transmit to 309. For example, when the reception intensity of the reception signal R of the front directional antenna 311 and the rear directional antenna 312 to which the antenna switching unit 309 is connected falls below a predetermined threshold, the data processing unit 310 uses the side directional antenna. A control signal for switching to the beams 313 and 314 is transmitted to the antenna switching unit 309.

  FIGS. 19A and 19B are explanatory diagrams of directional beams formed by the base station apparatus of the moving cell base station incorporated in the moving vehicle of FIG. The example of FIG. 19 is an example in which the antenna of the base station apparatus of the moving cell base station is arranged on the upper surface 42 of the roof (roof top) of the automobile 40. FIG. 19A is a diagram when the front directional antenna 311 and the rear directional antenna 312 are connected to the first wireless communication unit 302 to form a beam. FIG. 19B is a diagram when the side directivity antennas 313 and 314 are connected to the first wireless communication unit 302 to form a beam.

  The vehicle-mounted antenna is required to have a low-profile antenna in order to park in a parking lot with a height restriction or to maintain the car design. Further, in order to apply directional diversity, a narrow beam antenna having a high FB ratio (Front Back ratio) is required. On the other hand, if the beam is directed in the direction where the base station does not exist, the reception intensity may be deteriorated. For this reason, it is desirable to select a base station with the highest reception intensity by switching a beam with a switch using a thin unidirectional antenna. As a thin unidirectional antenna, for example, a printed Yagi-Uda antenna, a tapered slot antenna, or the like can be used.

  In FIG. 19A, a front directional antenna 311, a rear directional antenna 312, and side directional antennas 313 and 314 are installed on the upper surface 42 of the roof top of the automobile 40. When the reception intensity of the front directional antenna 311 and the rear directional antenna 312 is higher than that of the side directional antennas 313 and 314, the antenna switching unit 309 switches the front directional antenna 311 and the rear directional antenna 312 to the first. 1 The internal switch is switched to connect to the wireless communication unit 302. As a result, beams 311A and 312A are formed forward and backward with respect to the traveling direction F of the automobile 40, respectively.

  On the other hand, in FIG. 19B, the antenna switching unit 309 is configured such that the side directional antenna 313 is received when the reception strength of the side directional antennas 313 and 314 is higher than that of the front directional antenna 311 and the rear directional antenna 312. , 314 are switched so that the first wireless communication unit 302 is connected. Thereby, beams 313A and 314A are formed on the right side and the left side with respect to the traveling direction F of the automobile 40, respectively.

  As described above, the front directional antenna 311 and the rear directional antenna 312 are connected to the first wireless communication unit 302 by the switch of the antenna switching unit 309, so that the vehicle 40 travels forward and backward with respect to the traveling direction F, respectively. Beams 311A and 312A are formed. On the other hand, by connecting the lateral directional antennas 313 and 314 to the first wireless communication unit 302 with the switch of the antenna switching unit 309, beams 313A and 314A are formed on the right side and the left side with respect to the traveling direction F of the automobile 40, respectively. Is done. Using such a thin unidirectional antenna, the base station with the highest reception intensity can be selected by switching the beam with a switch.

  When the base station apparatus 300 of the moving cell base station can receive one base station, either the front directional antenna 311 and the rear directional antenna 312 or the side directional antennas 313 and 314 are used. By switching the beam with a switch, it is possible to select and use the directional antenna having the higher reception intensity.

  In the above embodiment, the case where the wireless communication device incorporated in the automobile 40 is the moving cell base station 30 has been described, but the wireless communication apparatus incorporated in the automobile 40 may be an apparatus other than the moving cell base station 30. Good. For example, in the present invention, as shown in FIG. 20, a wireless communication device incorporated in an automobile 40 includes a user apparatus (mobile station) having antennas 511 and 512 and a user apparatus main body 500 fixedly arranged with respect to the automobile 40. ) 50 can be applied in the same manner, and the same effect can be obtained.

  The present invention also provides a broadcast in which a radio communication device incorporated in a car 40 has a broadcast receiving antenna and a receiver main body fixedly arranged with respect to the car 40 and receives broadcast radio waves transmitted from a broadcast transmitting station. The same can be applied to the case of the receiving device, and the same effect can be obtained.

  In addition, the processing steps described in this specification and the components of the communication system, the wireless communication device, the base station device, and the user device (mobile station device, user terminal device, mobile device) can be implemented by various means. it can. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof. For example, the processing in the wireless communication apparatus (base station apparatus) according to the present embodiment is executed by reading a predetermined program into hardware described later, or executing a predetermined program incorporated in hardware described later. This is realized.

  Regarding hardware implementation, means such as a processing unit used to realize the above steps and components in an entity (for example, various wireless communication devices, NodeBs, terminals, hard disk drive devices, or optical disk drive devices) are 1 One or more application specific ICs (ASICs), digital signal processors (DSPs), digital signal processors (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, It may be implemented in a controller, microcontroller, microprocessor, electronic device, other electronic unit designed to perform the functions described herein, a computer, or a combination thereof.

  Also, for firmware and / or software implementation, means such as processing units used to implement the above components may be programs (eg, procedures, functions, modules, instructions) that perform the functions described herein. , Etc.). In general, any computer / processor readable medium that specifically embodies firmware and / or software code is means such as a processing unit used to implement the steps and components described herein. May be used to implement For example, the firmware and / or software code may be stored in a memory, for example, in a control device, and executed by a computer or processor. The memory may be implemented inside the computer or processor, or may be implemented outside the processor. The firmware and / or software code may be, for example, random access memory (RAM), read only memory (ROM), nonvolatile random access memory (NVRAM), programmable read only memory (PROM), electrically erasable PROM (EEPROM) ), FLASH memory, floppy disk, compact disk (CD), digital versatile disk (DVD), magnetic or optical data storage, etc. Good. The code may be executed by one or more computers or processors, and may cause the computers or processors to execute the functional aspects described herein.

  Also, descriptions of embodiments disclosed herein are provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. The present disclosure is therefore not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

10 mobile communication network 20 fixed base station (macrocell base station)
20A Fixed base station cell (macro cell)
21 Satellite stations (artificial satellites)
22 Fixed base stations (satellite earth stations)
23 Moored balloon 24 Moored balloon relay station 25 Fixed base station 30 Moving cell base station (mobile base station)
30A Moving cell 40 Car 41 Battery 50 User equipment (mobile station)
60 management apparatus 300 base station apparatus 302 first radio communication unit 304 second radio communication unit 306 relay control unit 308 storage unit 309 antenna switching unit 310 data processing unit 311 first antenna (forward directional antenna)
312 First antenna (rear directional antenna)
313 First antenna (right-handed directional antenna)
314 1st antenna (left side directional antenna)
315 Second antenna 316 First antenna (front antenna)
317 First antenna (rear antenna)
318 1st antenna (right side antenna)
319 First antenna (left side antenna)
320A, B First and second high-frequency signal processing units 321A, B Duplexer (DUP)
322A, B reception power amplifier 323A, B frequency shift detection unit 324A, B transmission power amplifier 325A, B frequency conversion unit 326 baseband processing unit 330 film type array antenna 331 antenna element

JP 2008-079246 A JP-A-8-107379

Claims (12)

A wireless communication device that can be attached to a mobile body,
A plurality of directional antennas having unidirectivity in a plurality of directions different from each other based on a main moving direction in which the moving body mainly moves;
A wireless communication unit for processing transmission signals and reception signals transmitted and received via the plurality of directional antennas ,
The plurality of directional antennas are:
A front directional antenna having unidirectionality directed in a main moving direction of the moving body;
A rear directional antenna having unidirectionality directed in a direction opposite to the main moving direction of the moving body;
A first lateral directional antenna having unidirectionality directed to one side in a direction crossing a main movement direction of the mobile body;
A second lateral directional antenna having unidirectionality directed to the other side of the mobile body,
The wireless communication unit
Detecting a Doppler frequency shift corresponding to the front directional antenna during movement of the moving body, based on a detection result of its so as to compensate for the Doppler frequency shift, the received signals and via the front directional antenna A signal processing unit for a forward directional antenna that processes at least one of the transmission signals;
Wherein said detecting a Doppler frequency shift corresponding to the backward directional antenna during movement of the movable body, based on a detection result of its so as to compensate for the Doppler frequency shift, the received signals and via the rear directional antenna A signal processing unit for a backward directional antenna that processes at least one of the transmission signals;
Detecting a Doppler frequency shift corresponding to the first side directional antenna during movement of the moving body, based on a detection result of its so as to compensate for the Doppler frequency shift, the first side oriented A signal processing unit for a first lateral directional antenna that processes at least one of a reception signal and a transmission signal via the directional antenna;
Detecting a Doppler frequency shift corresponding to the second lateral directional antenna during movement of the moving body, based on a detection result of its so as to compensate for the Doppler frequency shift, the second side oriented a second signal processing unit for lateral directional antenna for processing at least one of the received signal and the transmitted signal through the sex antenna, was closed,
When the received signal strength of the front directional antenna and the backward directional antenna is higher than the received signal strength of the first side directional antenna and the second side directional antenna, the front directional antenna The directional antenna and the rear directional antenna are connected to the wireless communication unit, and the received signal strength of the first side directional antenna and the second side directional antenna is the front directional antenna and the rear directional antenna. When the received signal strength is higher than that of the directional antenna, the first side directional antenna and the second side directional antenna are connected to the radio communication unit so as to be connected to the radio communication unit. A wireless communication apparatus , further comprising an antenna switching unit that switches antennas . The wireless communication device according to claim 1.
The wireless communication device, wherein the plurality of directional antennas are thin antennas installed on an outer surface portion of the moving body. The wireless communication device according to claim 1.
The wireless communication device, wherein the plurality of directional antennas are thin antennas installed on an upper surface portion of the moving body. The wireless communication device according to any one of claims 1 to 3,
The wireless communication device, wherein the plurality of directional antennas are installed at the same height of the moving body. The wireless communication device according to any one of claims 1 to 4,
The wireless communication apparatus, wherein the plurality of directional antennas are one of a film type array antenna and a patch antenna. The wireless communication apparatus according to any one of claims 1 to 5,
The signal processing unit converts a frequency of at least one of the reception signal and the transmission signal so as to compensate for the Doppler frequency shift based on a detection result of the Doppler frequency shift. The wireless communication device according to any one of claims 1 to 6,
A wireless communication apparatus, characterized in that it is a mobile base station that performs wireless communication over a backhaul line with a fixedly arranged base station of a mobile communication system. The wireless communication device according to any one of claims 1 to 6,
A wireless communication apparatus, characterized in that it is a mobile station that performs wireless communication with a base station of a mobile communication system. The wireless communication device according to any one of claims 1 to 6,
A wireless communication apparatus, which is a broadcast receiving apparatus that receives broadcast radio waves transmitted from a broadcast transmitting station. The wireless communication device according to any one of claims 1 to 9,
The wireless communication apparatus, wherein the moving body is a car including a passenger car, a bus, a truck, or a motorcycle, a railway vehicle that travels on a track, an aircraft, or a ship.   A moving body comprising the wireless communication device according to claim 1. The mobile body according to claim 11, wherein
A moving body comprising a passenger car, a bus, a truck, or a motor vehicle including a motorcycle, a railway vehicle traveling on a track, an aircraft, or a ship.

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