JP6642352B2 - Mobile communication system, communication device - Google Patents

Description

  The present invention relates to a mobile communication system and a communication device provided in the mobile communication system, and particularly to a technology for performing highly reliable communication.

  In multi-carrier communication typified by the OFDM (Orthogonal Frequency Division Multiplexing) method, as disclosed in Patent Document 1, a receiving apparatus performs channel estimation based on a received signal, and transmits a channel estimation result to a transmitting apparatus. May provide feedback. The transmitting apparatus schedules resources to be used for communication with the receiving apparatus based on the feedback channel estimation result, for example, so as to reduce power loss. As a result, a decrease in communication quality due to the influence of the multipath propagation path can be suppressed.

JP 2011-172160 A

  The effect of multipath varies depending on location and frequency. In a mobile communication device used in a mobile object, a position when transmitting a propagation path estimation result is often different from a position when performing communication with resources allocated based on the propagation path estimation result. Therefore, when performing communication, the effect of the multipath propagation path is different from when transmitting the propagation path estimation result, and even if communication is performed using resources determined based on the propagation path estimation result, high reliability is achieved. Communication could not be performed.

  The present invention has been made based on this situation, and an object of the present invention is to provide a mobile communication system and a communication device capable of performing highly reliable communication.

  The above object is achieved by a combination of features described in the independent claims, and the subclaims define further advantageous embodiments of the invention. Symbols in parentheses described in the claims indicate a correspondence relationship with specific means described in the embodiment described below as one aspect, and do not limit the technical scope of the present invention. .

  An invention according to a mobile communication system for achieving the above object is provided with an antenna for selected resources (313, 1372, 2372, 3273, 3373, 4313B) for use in a mobile object and for communicating with a selected resource, A mobile communication device (300, 1300, 2300, 3300, 4300) that performs wireless communication using an antenna for a selected resource, and a target communication device (200, 1200, 2,200, 3200, 3300, 4200) as a communication target of the mobile communication device ), Wherein the propagation path between the reference communication antenna and the target communication device has an antenna characteristic including at least an antenna type common to the selected resource antenna. Propagation path characteristic information, which is information on characteristics, is used for future communication positions. A mobile communication device and a target communication device at a communication position, based on the propagation path characteristic acquisition units (234, 1231, 2232, 3232, 3332, and 4231) acquired by the transmission path characteristic acquisition unit; And a resource selection unit (235, 1232, 2233, 3234, 3334, 4234) for selecting a resource used for communication with the mobile communication device before the selected resource antenna of the mobile communication device is located at the communication position.

  A propagation path characteristic acquisition unit acquires propagation path characteristic information, which is information on propagation path characteristics between a target antenna and a reference antenna having the same antenna characteristic as the selected resource antenna, in association with a future communication position. . Thereby, the resource selection unit can select a resource used for communication between the mobile communication device and the target communication device at the communication position in advance before the selected resource antenna of the mobile communication device is located at the communication position. . Therefore, since communication can be performed using the resource selected by the resource selection unit at the communication position, highly reliable communication can be performed.

  Further, an invention relating to a communication apparatus for achieving the above object is an invention having the same configuration as a target communication apparatus included in an invention relating to a mobile communication system. That is, the invention according to the communication device is used in a mobile object and communicates with a mobile communication device provided with a selected resource antenna for communicating with a selected resource (200, 1200, 2200, 3200, 3300, 4200), and associates propagation path characteristic information, which is information on propagation path characteristics between the reference antenna and the communication apparatus in which the antenna characteristic including at least the antenna type is common to the selected resource antenna, with the communication position. Communication between the mobile communication device and the communication device at the communication position based on the propagation path characteristic acquisition units (234, 1231, 2232, 3232, 3332, 4231) acquired and the propagation path characteristic information acquired by the propagation path characteristic acquisition unit. Resources to be used before the selected resource antenna of the mobile communication device is located at the communication position. Comprising scan selecting section (235,1232,2233,3234,3334,4232).

FIG. 2 is a diagram illustrating a configuration of a mobile communication system 1 according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration of a base station 200 in FIG. 1. It is a figure which illustrates the radio wave propagation map 221. FIG. 3 is a block diagram illustrating functions of a control unit 230 in FIG. 2. FIG. 2 is a block diagram illustrating a configuration of the in-vehicle terminal 300 in FIG. 1. FIG. 6 is a block diagram illustrating functions of a control unit 330 of FIG. 5. FIG. 13 is a block diagram illustrating functions provided in a control unit 230 of the base station 200 in the second embodiment. It is a block diagram showing the function with which control part 330 of in-vehicle terminal 300 has in a 3rd embodiment. It is a figure explaining the composition of mobile communication system 1000 of a 4th embodiment. FIG. 10 is a block diagram illustrating a configuration of the in-vehicle terminal 1300 in FIG. 9. FIG. 11 is a block diagram illustrating functions of a control unit 1330 of FIG. 10. FIG. 10 is a block diagram illustrating a configuration of a base station 1200 in FIG. 9. It is a figure showing the example of communication of mobile communications system 1000 of a 4th embodiment. FIG. 12 is a diagram illustrating channel characteristic information CC determined by a characteristic information determining unit 1331 in FIG. 11. It is a block diagram showing the function with which control part 1230 of base station 1200 is provided in a 5th embodiment. It is a figure explaining the composition of mobile communication system 2000 of a 6th embodiment. FIG. 17 is a block diagram illustrating a configuration of a second vehicle-mounted terminal 2300 in FIG. 16. FIG. 18 is a block diagram illustrating functions of a control unit 2330 of FIG. 17. FIG. 17 is a block diagram illustrating a configuration of a first vehicle-mounted terminal 2200 in FIG. 16. FIG. 20 is a block diagram illustrating functions of a control unit 2230 of FIG. 19. FIG. 21 is a diagram illustrating channel characteristic information CC determined by a characteristic information determining unit 2231 in FIG. 20. It is a figure explaining the composition of mobile communications system 3000 of a 7th embodiment. FIG. 23 is a block diagram showing a configuration of a first vehicle-mounted terminal 3200 in FIG. 22. FIG. 23 is a block diagram illustrating a configuration of a second in-vehicle terminal 3300 in FIG. 22. FIG. 24 is a block diagram illustrating functions of a control unit 3230 of FIG. 23. FIG. 25 is a block diagram illustrating functions of a control unit 3330 of FIG. 24. 27 is a diagram illustrating propagation path characteristic information CC determined by a characteristic information determining unit 3231 in FIG. 26. FIG. It is a figure explaining the composition of mobile communication system 4000 of an 8th embodiment. FIG. 29 is a block diagram showing a configuration of an in-vehicle terminal 4300 in FIG. 28. FIG. 30 is a diagram illustrating functions provided in a control unit 4330 of FIG. 29. FIG. 31 is a diagram illustrating an example of assignment of a front antenna 4313A and a rear antenna 4313B assigned by the communication control unit 4332 in FIG. 30. FIG. 32 is a diagram illustrating assignment of a front antenna 4313A and a rear antenna 4313B, which is different from FIG. 31. FIG. 29 is a block diagram illustrating a configuration of a base station 4200 in FIG. 28. 34 is a diagram illustrating functions provided in a control unit 4230 of FIG. 33. FIG. FIG. 35 is a diagram illustrating a relationship between an index used by the resource selection unit 4232 of FIG. 34 to select a spatial resource and a use form of the antenna element 4313.

<First embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The mobile communication system 100 according to the first embodiment includes a base station 200 and an in-vehicle terminal 300 as shown in FIG. The in-vehicle terminal 300 corresponds to the mobile communication device described in the claims.

  The base station 200 corresponds to a target communication device or a communication device in the claims, and is fixed to a predetermined place and communicates with the in-vehicle terminal 300. The in-vehicle terminal 300 is mounted on a vehicle 4 that is a moving body. The vehicle 4 here means an automobile. In the example of FIG. 1, the vehicle 4 is traveling on a road 5. In FIG. 1, vehicles 4 are shown at three points P1, P2, and P3, respectively. The vehicles 4 located at these three points indicate that the same vehicle 4 has sequentially moved from the point P1 to the points P2 and P3. Therefore, although only one vehicle 4 is shown in FIG. 1, the in-vehicle terminal 300 is mounted on each of the plurality of vehicles 4. Further, a plurality of base stations 200 may be provided.

[Configuration of Base Station 200]
The base station 200 includes a communication unit 210, a storage unit 220, and a control unit 230, as shown in FIG. The communication unit 210 includes a transmission unit 211, a reception unit 212, and an antenna 213. The transmission unit 211 modulates and amplifies various signals input from the control unit 230, and transmits the signals to the outside via the antenna 213. The transmission unit 211 of this embodiment sets the access method to OFDMA (frequency-division multiple access) and sets the modulation method to a method selected from phase shift keying and quadrature amplitude modulation. The receiving section 212 demodulates the signal received by the antenna 213 and inputs the demodulated signal to the control section 230.

  The storage unit 220 is writable, and stores a radio wave propagation map 221 and a road map database 223. The radio wave propagation map 221 is a database storing propagation path characteristic information CC at various communication positions. The channel characteristic information CC is information representing the channel characteristics for which estimation is performed in OFDM. The channel characteristic information CC of the present embodiment means the frequency characteristics of the channel, and is the intensity and phase characteristics with respect to frequency. FIG. 3 illustrates the relationship between the frequency and the SN ratio at various communication positions as the propagation path characteristic information CC. From the radio wave propagation map 221, it is possible to know which frequency has a better SN ratio at various communication positions. The radio wave propagation map 221 is created for each type of the in-vehicle terminal 300.

  The reason that the radio wave propagation map 221 is created for each type of the in-vehicle terminal 300 is that if the type of the in-vehicle terminal 300 is different, the antenna characteristics are different from those of the antenna 313 provided in the in-vehicle terminal 300. In the present embodiment, the antenna 313 functions as both the reference antenna and the selected resource antenna in the claims. Since the radio wave propagation map 221 is created for each type of the in-vehicle terminal 300, the radio wave propagation map 221 is created for each antenna 313 of the in-vehicle terminal 300. In addition, since the antenna 313 functions as a reference antenna, the radio wave propagation map 221 is created for each of the plurality of reference antennas. Further, the type of the in-vehicle terminal 300 corresponds to the antenna determination information.

  By creating the radio wave propagation map 221 for each type of the in-vehicle terminal 300, the radio wave propagation map 221 can be created based on the propagation path characteristic information CC acquired by the antenna having the same antenna characteristic. However, even if the antenna characteristics are not the same, the radio wave propagation map 221 is created based on the propagation path characteristic information CC obtained by communication with the base station 200 using the reference antenna having the same antenna characteristic as the selected resource antenna. May be. The antenna characteristics are specifically determined by the directivity and sensitivity in the installed state, or the characteristics that affect them. For example, the antenna type is one factor that determines antenna characteristics. The antenna type is sometimes called an antenna type. Even if antennas of the same antenna type are installed in different states, the antenna characteristics are generally different. For example, when an antenna of the same type is installed on the roof of a vehicle and when it is installed indoors, the antenna characteristics are not common because the directivity changes. Further, the attitude of the antenna may be included in the antenna characteristics.

  Even if the antenna type and the antenna attitude are not the same, the antenna characteristics may be common if they are similar. The degree to which the antenna characteristics are common can be appropriately set according to the required accuracy.

  The radio wave propagation map 221 includes a reliability index database 222. The reliability index database 222 is a database for a reliability index for each channel characteristic information CC included in the radio wave propagation map 221. The reliability index is an index indicating how reliable the corresponding channel characteristic information CC is. In the present embodiment, the reliability index is determined based on a reproducibility index indicating how much the channel characteristic information CC is reproduced.

  The reproducibility index is a value indicating the spread of the distribution of the propagation path characteristic information CC acquired a plurality of times at substantially the same communication position, and the wider the spread, the lower the reproducibility index is. Value. What degree of position difference is made substantially the same may be appropriately set according to required accuracy.

  The reliability index is, for example, a value obtained by lowering the reproducibility index for the resource in which the error has occurred, as the error occurs. The road map database 223 is a database representing a road map in a digital format.

  The control unit 230 is a computer including a CPU 242, a ROM 250, and a RAM 260. The CPU 242 uses a temporary storage function of the RAM 260 and stores the data in a non-transitory tangible storage medium such as the ROM 250. Run the program that is being run. Thereby, the control unit 230 functions as each unit illustrated in FIG. When the control unit 230 executes these functions, a method corresponding to the program is executed. Note that some or all of the functions executed by the control unit 230 may be configured in hardware by one or more ICs or the like.

[Configuration of Control Unit 230]
As shown in FIG. 4, the control unit 230 includes a map update unit 231, a position prediction information acquisition unit 232, a position prediction unit 233, a channel characteristic acquisition unit 234, a resource selection unit 235, a communication control unit 236, and a reliability update unit 237. Is provided.

  First, the map updating unit 231 will be described. The base station 200 periodically transmits the reference signal R to the surroundings. The reference signal R is a channel estimation signal described in the claims. The reference signal R is a pilot signal whose amplitude and phase are known, or a signal partially including the pilot signal, and is a signal in which a known signal is assigned to all sub-channels. When receiving the reference signal R, the in-vehicle terminal 300 determines the propagation path characteristic information CC based on the reception state of the received reference signal R.

  The in-vehicle terminal 300 asynchronously uploads the determined propagation path characteristic information CC to the base station 200 together with the position of the reference signal R at the time of reception and the type of the in-vehicle terminal 300. When receiving section 212 of base station 200 receives the propagation path characteristic information CC and the like, map updating section 231 acquires propagation path characteristic information CC, reception position, and model of in-vehicle terminal 300 from receiving section 212. Then, the radio wave propagation map 221 to be updated is specified based on the obtained model, and the specified radio wave propagation map 221 is updated using the propagation path characteristic information CC obtained from the receiving unit 212 and the reception position. As an example, the update method includes, as an example, the channel characteristic information CC and the acquired channel characteristic information CC in the radio wave propagation map 221 corresponding to the acquired reception position, the number of the acquired channel characteristic information CC. There is a method of performing weighted averaging according to.

  Next, the position prediction information acquisition unit 232 will be described. As will be described later, the in-vehicle terminal 300 transmits the position prediction information to the base station 200. The position prediction information includes the position of the antenna 313 at the time when the vehicle-mounted terminal 300 transmits the position prediction information (hereinafter, the position at the time of upload), the moving speed of the vehicle-mounted terminal 300 at the time of upload, the ID of the vehicle-mounted terminal 300, and the vehicle-mounted terminal. And the model of the terminal 300. By including the position at the time of upload and the moving speed, the position of the antenna 313 after the time of upload can be predicted. Further, the traveling direction of the vehicle-mounted terminal 300 may be included in the position prediction information. However, the traveling direction can be predicted from the time change of the uploading position. In addition, when the direction in which the road extends is used in addition to the time change of the uploading position, the traveling direction can be more accurately predicted. Therefore, it is not essential that the position prediction information include the traveling direction. This position prediction information is received by the receiving unit 212 of the base station 200. The position prediction information acquisition unit 232 acquires the position prediction information from the reception unit 212.

  The position prediction unit 233 sequentially determines a future predicted position of the antenna 313 of the vehicle-mounted terminal 300 based on the position prediction information acquired by the position prediction information acquisition unit 232. Specifically, based on the moving speed of the vehicle-mounted terminal 300 included in the position prediction information and the elapsed time from when the position prediction information is received, the vehicle-mounted terminal 300 moves from the time when the vehicle-mounted terminal 300 uploads the position prediction information. The calculated moving distance is calculated. The position moved by the moving distance from the position at the time of upload in the moving direction of the vehicle-mounted terminal 300 is the predicted position. In addition, the moving direction of the vehicle-mounted terminal 300 may be determined based on the movement trajectory of the vehicle-mounted terminal 300 determined from the position prediction information sequentially acquired from the same vehicle-mounted terminal 300. When the position prediction information includes the traveling direction of the vehicle-mounted terminal 300, the traveling direction may be used as the moving direction of the vehicle-mounted terminal 300.

  The propagation path characteristic acquisition unit 234 uses the predicted position predicted by the position prediction unit 233 as the communication position, and acquires the propagation path characteristic information CC at the communication position from the radio wave propagation map 221 in association with the communication position. The position prediction information includes the type of the in-vehicle terminal 300, and the radio wave propagation map 221 is also created for each type of the in-vehicle terminal 300. Therefore, the radio wave propagation map 221 for acquiring the propagation path characteristic information CC is the same radio wave propagation map 221 as the type of the in-vehicle terminal 300 included in the position prediction information. In FIG. 3, as an example, the propagation path characteristic information CC (P2) acquired from the radio wave propagation map 221 when the point P2 is set as the predicted position is indicated by a solid line and a dotted line.

  The resource selection unit 235 uses the predicted position predicted by the position prediction unit 233 (that is, a future communication position) based on the propagation path characteristic information CC acquired by the propagation path characteristic acquisition unit 234 for communication with the in-vehicle terminal 300. Select a resource. For example, as shown in FIG. 3, the propagation path characteristic information CC (P2) has a high SN ratio between frequencies f1 and f2. Therefore, a subcarrier that uses a frequency between frequencies f1 and f2 is selected as a frequency resource used for communication with the in-vehicle terminal 300 in the time slot to which the time at which the in-vehicle terminal 300 is located at the communication position belongs. Thereby, a frequency resource in a certain time slot (that is, a time resource) is selected.

  It should be noted that the resource is selected using the reliability index corresponding to the channel characteristic information CC. For a frequency resource with a relatively low reliability index, the SN ratio is corrected to a relatively small value because of the low reliability, and a frequency resource is selected.

  In the above description, the channel characteristic information CC is acquired for only one in-vehicle terminal 300. However, when the channel characteristic information CC for a plurality of in-vehicle terminals 300 is acquired, the resource allocation is optimized. Need to be

  The optimization is performed, for example, such that the total amount or the average of the time and frequency resources in which the radio wave attenuation for one or more in-vehicle terminals 300 is equal to or less than a certain value (that is, the SN ratio is equal to or more than a certain value) is maximized. Note that, after acquiring the propagation path characteristics, a method of selecting a frequency resource based on the propagation path characteristics may be the same as the method used in the existing system such as the LTE cellular system.

  The resource selection unit 235 selects a resource used for communication with the in-vehicle terminal 300 at a predicted position, that is, a position where the in-vehicle terminal 300 has not yet reached. Therefore, the resource is selected before the antenna 313 of the in-vehicle terminal 300 is located at the predicted position (that is, the communication position).

  The communication control unit 236 controls the transmitting unit 211 as the resource selected by the resource selection unit 235 while sequentially determining the position of the vehicle-mounted terminal 300 based on the position prediction information, and Communication.

  In this communication, the modulation scheme can be selected from phase shift keying and quadrature amplitude modulation as described in the transmission section 211. Phase shift keying includes BPSK and QPSK, and quadrature amplitude modulation includes 16QAM, 64QAM, 256QAM, and the like. These BPSK, QPSK, 16QAM, 64QAM, and 256QAM have a relationship in which the communication speed and the reliability are in conflict, and the higher the communication speed, the lower the reliability. Therefore, the reliability of the selected resource is determined based on the S / N ratio, and the higher the reliability is, the higher the communication speed is selected. In other words, a modulation method with a lower communication speed is selected as the reliability is lower. Further, the lower the reliability, the higher the redundancy (that is, the smaller the coding rate). In the example of FIG. 1, when the vehicle 4 is located at the point P2, the base station 200 transmits a signal to the in-vehicle terminal 300 using the selected frequency resource.

  Although the above description of the communication control unit 236 is for the downlink, the communication control unit 236 can also communicate with the in-vehicle terminal 300 using the resources selected by the resource selection unit 235 for the uplink. .

  When the resource selected by the resource selection unit 235 is used in the uplink, the communication control unit 236 transmits a signal indicating the resource selected by the resource selection unit 235 to the in-vehicle terminal before the in-vehicle terminal 300 is located at the communication position. What is necessary is just to transmit to the terminal 300.

  When the in-vehicle terminal 300 receives the signal transmitted by the base station 200, the in-vehicle terminal 300 determines a signal error and uploads error resource information including the resource in which the error has occurred and the position of the antenna 313 at that time to the base station 200. I do.

  When the receiving unit 212 of the base station 200 receives the error resource information, the reliability updating unit 237 acquires the error resource information from the receiving unit 212. Then, based on the obtained error resource information, among the reliability indexes of the reliability index database 222, the communication position and the frequency resource reliability index determined by the error resource information are reduced by a predetermined amount or a predetermined ratio.

[Configuration of In-Vehicle Terminal 300]
As shown in FIG. 5, the in-vehicle terminal 300 includes a communication unit 310, a storage unit 320, and a control unit 330. The communication unit 310 includes a transmission unit 311, a reception unit 312, and an antenna 313. The transmission unit 311 modulates and amplifies various signals input from the control unit 330, and transmits the signals to the outside via the antenna 313. The transmission unit 311 of the present embodiment sets the access method to SC-FDMA and sets the modulation method to a method selected from phase shift keying and quadrature amplitude modulation. Receiving section 312 demodulates the signal received by antenna 313 and inputs the demodulated signal to control section 330. As described above, the antenna 313 functions as both the reference antenna and the selected resource antenna in the claims. The storage unit 320 can write various information under the control of the control unit 330.

  The control unit 330 is a computer including a CPU 342, a ROM 350, and a RAM 360. The CPU 342 executes a program stored in a non-transitional substantial recording medium such as the ROM 350 while using the temporary storage function of the RAM 360. Thereby, the control unit 330 functions as each unit illustrated in FIG. When the control unit 330 executes these functions, a method corresponding to the program is executed. Note that some or all of the functions executed by the control unit 330 may be configured in hardware by one or more ICs or the like.

  The speed sensor 41 sequentially detects the moving speed of the in-vehicle terminal 300 and inputs the detected moving speed to the control unit 330. As the speed sensor 41, a vehicle speed sensor that detects the speed of the vehicle 4 can be used.

  The position detector 42 includes a GNSS (Global Navigation Satellite System) receiver that receives a navigation signal transmitted by a navigation satellite included in the Global Navigation Satellite System (GNSS). The current position is sequentially detected based on the navigation signal received by the GNSS receiver. Then, the detected current position is sequentially input to the control unit 330.

[Configuration of Control Unit 330]
As shown in FIG. 6, the control unit 330 includes a position determination unit 331, a communication control unit 332, an error detection unit 338, and a characteristic information determination unit 339. The position determining unit 331 sequentially determines the current position of the antenna 313 by sequentially acquiring the current position detected by the position detector 42. Note that the current position detected by the position detector 42 is the position where the position detector 42 is arranged, not the current position of the antenna 313. Therefore, the current position detected by the position detector 42 may be corrected based on the difference between the position of the antenna 313 and the position of the position detector 42, and may be used as the current position of the antenna 313. However, in the present embodiment, the antenna 313 functions as a reference antenna and an antenna for a selected resource. Therefore, even if the position of the position detector 42 is set to the position of the reference antenna and the position of the selected resource antenna, there is no influence on the accuracy of determining that the selected resource antenna is located at the position of the reference antenna. When the position error of the reference antenna is equal to the position error of the antenna for the selected resource, it is not necessary to correct the current position detected by the position detector 42 to be the current position of the antenna 313.

  The communication control unit 332 includes a reception control unit 333 and a transmission control unit 334. Reception control section 333 decodes a signal of a resource block allocated to its own terminal among signals transmitted from base station 200 and received by antenna 313. Which resources are allocated to the own terminal is determined using a method predetermined for each wireless system. For example, in an LTE cellular system, a determination is made based on allocation information contained in a control channel area in each radio frame. Since the antenna 313 is used to receive the signal of the resource selected by the resource selection unit 235 of the base station 200, the antenna 313 corresponds to a selected resource antenna in the claims.

  Before describing the transmission control unit 334, the error detection unit 338 and the characteristic information determination unit 339 will be described. The error detection unit 338 detects whether or not there is an error in a signal transmitted using resources allocated to the own terminal, using a known error detection method based on an error correction code or the like.

  When the receiving unit 312 receives the reference signal R from the base station 200 and acquires the reference signal R from the receiving unit 312, the characteristic information determining unit 339 determines the propagation path characteristic information CC based on the receiving state of the reference signal R. To determine. The method of estimating the channel characteristic information CC based on the received reference signal R may be the same as the method widely used in MIMO or the like. The channel characteristic information CC is also called a channel state or a channel estimation result. The channel characteristic information CC is represented by, for example, power and phase for each frequency.

  The transmission control unit 334 includes a characteristic determination information upload unit 335, a position prediction information upload unit 336, and an error resource upload unit 337. The characteristic determination information upload unit 335 uploads the position at the time of reception of the reference signal R, the propagation path characteristic information CC determined by the characteristic information determination unit 339, and the model of the in-vehicle terminal 300 from the transmission unit 311 to the base station 200. I do. The upload timing is not limited by the timing at which the propagation path characteristic information CC is determined, and may be an asynchronous timing. In the example of FIG. 1, when the vehicle 4 is located at the point P1, the in-vehicle terminal 300 uploads the propagation path characteristic information CC.

  The channel characteristic information CC uploaded by the characteristic determination information upload unit 335 is used for updating the radio wave propagation map 221 in the map update unit 231 of the control unit 230 provided in the base station 200, as described above. Therefore, the antenna 313 functions as a reference antenna.

  The position prediction information upload unit 336 uploads the above-described position prediction information to the base station 200 sequentially. As described above, the position prediction information includes the upload position, which is the position of the antenna 313 when the position prediction information is transmitted from the vehicle-mounted terminal 300, the moving speed of the vehicle-mounted terminal 300 at the time of upload, and the ID of the vehicle-mounted terminal 300. And the model of the in-vehicle terminal 300.

  The error resource upload unit 337 uploads error resource information indicating a resource used for transmitting a signal in which the error detection unit 338 has detected an error to the base station 200. The error resource information is information including a frequency resource in which an error has occurred and a position when the error has occurred.

  The timing for uploading the error resource information may be an asynchronous timing. In the example of FIG. 1, when the vehicle 4 is located at the point P3, the in-vehicle terminal 300 uploads error resource information on an error detected at the point P2.

[Summary of First Embodiment]
As described above, in the first embodiment described above, the base station 200 associates the propagation path characteristic information CC when the base station 200 communicated with the base station 200 with the antenna 313 in the past with the predicted position, that is, the future communication position, and 221 is provided with a propagation path characteristic acquisition unit 234 that acquires from 221.

  By acquiring the propagation path characteristic information CC in association with a future communication position, the resource selection unit 235 allows the antenna 313 of the on-board terminal 300 to allocate resources used for communication between the on-board terminal 300 and the base station 200 at the communication position. It can be selected before being located at the communication location. Thereby, since communication can be performed using the resource selected by the resource selection unit 235 at the communication position, highly reliable communication can be performed.

<Second embodiment>
Next, a second embodiment will be described. In the following description of the second embodiment, elements having the same reference numerals as those used so far are the same as the elements of the same reference numerals in the previous embodiments, unless otherwise specified. When only a part of the configuration is described, the above-described embodiment can be applied to the other part of the configuration.

  In the second embodiment, as shown in FIG. 7, the control unit 230 includes a distance determination unit 238, a characteristic change determination unit 239, and a characteristic change compensation unit 240 in addition to the configuration of the first embodiment.

  The distance determining unit 238 acquires the moving speed of the vehicle-mounted terminal 300 included in the position prediction information from the receiving unit 212 that has received the position prediction information. The moving distance during one communication period is determined by multiplying the moving speed by a preset communication time per communication.

  The characteristic change determination unit 239 determines a communication position at the time of starting communication based on the prediction result of the position prediction unit 233. Further, the communication position at the end of communication is determined by adding the movement distance during one communication period determined by the distance determination unit 238 to the communication position at the start of communication. Then, the channel characteristic information CC at the communication position at the start of communication and the channel characteristic information CC at the communication position at the end of communication are obtained from the radio wave propagation map 221 respectively.

  Next, the ratio of the channel characteristic information CC at the communication position at the end of the communication to the channel characteristic information CC at the communication position at the start of the communication is defined as a change in the channel characteristic information CC during the communication period.

  The characteristic change compensating section 240 performs compensation on the communication signal, which reduces the influence of the change in the propagation path characteristic information CC during the communication period on the communication determined by the characteristic change determining section 239. Here, the communication signal includes a transmission signal and a reception signal. To perform this compensation, the radio wave propagation map 221 is necessary. Therefore, if the side having the radio wave propagation map 221 is the transmitting side, the communication signal is a transmission signal, and the receiving side has the radio wave propagation map 221. If so, the communication signal is a received signal.

  In the present embodiment, the base station 200 includes the radio wave propagation map 221. Therefore, when the base station 200 transmits a signal, compensation is performed on the signal transmitted by the base station 200, and when the base station 200 receives a radio wave, the signal received by the base station 200 is compensated. Make compensation.

  For example, when the characteristic change determination unit 239 determines that the SN ratio is reduced by half at the end of transmission with respect to the start of transmission, the transmission power of the signal at the end of transmission is increased. The transmission power is twice the transmission power at that time. Also, regarding the phase, when it is determined by the characteristic change determining unit 239 that the phase advances by 90 degrees at the end of transmission with respect to the start of transmission, the phase of the signal at the end of transmission is changed to the phase at the start of transmission. Is transmitted with a delay of 90 degrees. The transmission power and phase between the start of transmission and the end of transmission may be determined by interpolation.

  Unlike this example, compensation can be performed on the uplink, that is, on the signal transmitted by the in-vehicle terminal 300. When compensating the uplink signal, the power and phase are compensated before demodulating the signal received by the antenna 213.

  Furthermore, if the in-vehicle terminal 300 is provided with the radio wave propagation map 221 by downloading the radio wave propagation map 221 from the base station 200, the in-vehicle terminal 300 will be able to use the distance determination unit 238, the characteristic change determination unit 239, A unit 240 may be provided.

  As in the second embodiment, the propagation path characteristic information CC at the start of communication is compared with the propagation path characteristic information CC at the end of communication, and compensation is performed so as to reduce the influence of a change in the propagation path characteristic information CC on communication. Is performed, the communication reliability is further improved.

<Third embodiment>
In the third embodiment, the in-vehicle terminal 300 downloads the radio wave propagation map 221 stored in the storage unit 220 of the base station 200 and stores it in the storage unit 320. In the third embodiment, the storage unit 320 corresponds to a download data storage unit in the claims.

  The radio wave propagation map 221 stored in the storage unit 320 may be the entire radio wave propagation map 221 stored in the storage unit 220 of the base station 200, or may be limited to the vicinity of the current position of the in-vehicle terminal 300. .

  As shown in FIG. 8, in the third embodiment, the control unit 330 of the in-vehicle terminal 300 includes a difference determination unit 340 in addition to the configuration of the first embodiment.

  The difference determining unit 340 corresponds to the channel characteristic information CC determined by the characteristic information determining unit 339 and the channel characteristic information CC determined by the characteristic information determining unit 339 in the radio wave propagation map 221 stored in the storage unit 320. A propagation path characteristic difference that is a difference from the portion is determined. This channel characteristic difference may be determined by using one channel characteristic information CC for each communication position as a unit, or dividing one channel characteristic information CC for each communication position into a plurality of frequency bands. You may determine by comparison.

  The characteristic determination information upload unit 335 in the third embodiment uploads the propagation path characteristic difference determined by the difference determination unit 340 as characteristic determination information. By doing so, the amount of data to be uploaded is reduced, so that it is possible to prevent the communication band from being overwhelmed.

<Fourth embodiment>
As shown in FIG. 9, a mobile communication system 1000 according to the fourth embodiment includes a base station 1200 corresponding to a target communication device in the claims and an in-vehicle terminal 1300 corresponding to a mobile communication device in the claims. Each of the base station 1200 and the in-vehicle terminal 1300 may be provided in plurality.

[Configuration of In-Vehicle Terminal 1300]
As shown in FIG. 9, the in-vehicle terminal 1300 includes a front antenna 1371 and a rear antenna 1372. These antennas 1371 and 1372 are antennas having the same structure, and are arranged on the roof of the vehicle 4 so as to be in a front-rear relationship with the traveling direction of the vehicle 4 and at the same height. The front antenna 1371 functions as a reference antenna, and the rear antenna 1372 functions as a selected resource antenna.

  As shown in FIG. 10, the in-vehicle terminal 1300 includes a communication unit 1310, a storage unit 1320, and a control unit 1330. The communication unit 1310 includes a transmission unit 1311 and a reception unit 1312. The transmission unit 1311 and the reception unit 1312 perform transmission and reception by switching between the two antennas 1371 and 1372. Except for having an antenna switching function, the transmission unit 1311 and the reception unit 1312 have the same functions as the transmission unit 311 and the reception unit 312 of the first embodiment.

  As shown in FIG. 11, the control unit 1330 includes a characteristic information determination unit 1331 and a reception information transmission unit 1332 as functions. First, the characteristic information determining unit 1331 will be described. Also in the fourth embodiment, the base station 1200 periodically transmits the reference signal R. The reference signal R can be received by either the front antenna 1371 or the rear antenna 1372.

  The characteristic information determining unit 1331 obtains the reference signal R received by the front antenna 1371 and the rear antenna 1372 from the receiving unit 1312, and converts the channel characteristic information CC in the same manner as the characteristic information determining unit 339 of the first embodiment. decide. Hereinafter, the channel characteristic information CC determined from the reference signal R received by the front antenna 1371 will be referred to as front antenna channel characteristic information CCA, and the channel characteristic information CC determined from the reference signal R received by the rear antenna 1372 will be referred to as the rear antenna. This is assumed to be antenna propagation path characteristic information CCB.

  The reception information transmission unit 1332 includes the front antenna channel characteristic information CCA determined by the characteristic information determination unit 1331, the rear antenna channel characteristic information CCB, and the moving speed of the on-board terminal 1300 when the reference signal R is received. The distance between front antenna 1371 and rear antenna 1372 and the ID of in-vehicle terminal 300 are transmitted from transmitting section 1311 to base station 1200.

[Configuration of Base Station 1200]
The base station 1200 has the same hardware configuration as the base station 200 of the first embodiment. As shown in FIG. 12, the base station 1200 has the same hardware configuration as that of the base station 200 of the first embodiment. A communication unit 1210, a storage unit 1220, and a control unit 1230. Therefore, the transmission unit 1211, the reception unit 1212, and the antenna 1213 included in the communication unit 1210 are the same as the transmission unit 211, the reception unit 212, and the antenna 213 included in the communication unit 210 in FIG.

  The control unit 1230 has a different function from the control unit 230 of FIG. As illustrated in FIG. 12, the control unit 1230 includes, as functions, a channel characteristic acquisition unit 1231, a resource selection unit 1232, a timing determination unit 1233, and a communication control unit 1234.

  The propagation path characteristic acquisition unit 1231 acquires, from the reception unit 1212, the front antenna propagation path characteristic information CCA and the rear antenna propagation path characteristic information CCB transmitted by the reception information transmission unit 1332 of the in-vehicle terminal 1300 and received by the reception unit 1212. I do. It is also assumed that the in-vehicle terminal 1300 is located at the reception position (that is, the communication position) at the time of acquisition. That is, the front antenna channel characteristic information CCA and the rear antenna channel characteristic information CCB are associated with the position at the time of reception.

  The resource selection unit 1232 sets a position where the front antenna 1371 receives the reference signal R as a communication position, and determines a resource used for communication at the communication position based on the front antenna channel characteristic information CCA acquired by the channel characteristic acquiring unit 1231. To decide.

  The resource selecting unit 1232 further determines a resource in a later timing later period. The post-rear timing period is after the rear communication timing determined by the timing determination unit 1233 described below, and continues until the rear antenna 1372 is predicted to reach the position of the front antenna 1371 at the rear communication timing. Period.

  In addition, the moving speed of the vehicle-mounted terminal 300 is used to determine the rear communication timing. The timing at which the reference signal R corresponding to the front antenna channel characteristic information CCA acquired together with the moving speed is transmitted is referred to as front communication timing. The front communication timing is time t1 in FIGS. 13 and 14, the rear communication timing is time t2 in FIGS. 13 and 14, and an example of the rear timing post period is time t3 in FIGS. 13 and 14. .

  In the post-rear timing period, the channel characteristic information CC can be expected to be between the front antenna channel characteristic information CCA acquired by the channel characteristic acquisition unit 1231 at the front communication timing and the rear communication timing, respectively. Based on the channel characteristic information CC that can be predicted, resources in the period after the rear timing are determined.

  Based on the moving speed of the in-vehicle terminal 1300 received by the receiving unit 1212, the timing determining unit 1233 sets the position of the rear antenna 1372 to the position where the front antenna 1371 receives the reference signal R (that is, the above-described communication position). Determine the timing. This timing is the above-mentioned rear communication timing.

  The communication control unit 1234 periodically transmits the above-described reference signal R from the transmission unit 211. Also, at the rear communication timing determined by the timing determination unit 1233, the resource selection unit 1232 communicates with the vehicle-mounted terminal 1300 using the resource selected as the resource to be used at the rear communication timing. The communication is specifically transmission, and transmits an arbitrary signal using the selected resource. Further, in addition to this arbitrary signal, the reference signal R is transmitted using all subchannels. This communication control unit 1234 corresponds to a target device side communication control unit in the claims.

  The communication control unit 1234 further communicates with the in-vehicle terminal 1300 using the resource selected by the resource selection unit 1232 as the resource to be used in the post-post-timing period during the post-post-timing period.

[Communication Example of Fourth Embodiment]
At time t1 shown in FIG. 13A, base station 1200 is transmitting reference signal R (t1), and in-vehicle terminal 1300 is receiving the reference signal R (t1). After the time t1, the characteristic information determination unit 1331 of the in-vehicle terminal 1300 acquires the reference signal R (t1) received by the front antenna 1371, and determines the front-side antenna channel characteristic information CCA. Then, before time t2, reception information transmitting section 1332 transmits the front antenna channel characteristic information CCA, the moving speed, and the ID of in-vehicle terminal 300 to base station 1200. The channel characteristic acquiring unit 1231 of the base station 1200 acquires the front-side antenna channel characteristic information CCA and the like from the receiving unit 1212.

  FIG. 14A illustrates the front-side antenna channel characteristic information CCA acquired by the channel characteristic acquiring unit 1231 in the state of FIG. 13A. In the front-side antenna propagation path characteristic information CCA shown in this figure, the horizontal axis represents frequency, and the vertical axis represents SN ratio. The front-side antenna channel characteristic information CCA shown in FIG. 14A has a different SN ratio depending on the frequency.

  Therefore, the resource selection unit 1232 of the base station 1200 selects a frequency channel with a good SN ratio as a resource used at a communication position. In FIG. 14A, since the frequencies f3 to f4, f5 to f6, and f7 to f8 are frequency bands having a good SN ratio, a frequency channel using these frequency bands is selected as a resource used at a communication position.

  In addition, the timing determination unit 1233 determines the rear communication timing based on the moving speed of the vehicle-mounted terminal 1300. The rear communication timing is a timing at which the rear antenna 1372 is located at the communication position of the front antenna 1371. The rear communication timing transmits a reference signal R corresponding to the front antenna channel characteristic information CCA, which is a time that can be calculated by dividing the distance between the front antenna 1371 and the rear antenna 1372 by the moving speed of the vehicle-mounted terminal 1300. It is the time added to the time that was done.

  At this rear communication timing, the base station 1200 communicates with the in-vehicle terminal 1300. Time t2 shown in FIG. 14B is the rear communication timing. At time t2, the communication control unit 1234 is transmitting the reference signal R. The characteristic information determination unit 1331 and the reception information transmission unit 1332 of the control unit 1330 of the in-vehicle terminal 1300 determine the front-side antenna propagation path characteristic information CCA, the rear-side antenna propagation path characteristic information CCB, and the like. 1200.

  In FIG. 14B, front antenna channel characteristic information CCA (t1) indicated by a dotted line is front antenna channel characteristic information CCA at time t1. The front antenna channel characteristic information CCA (t2) indicated by the solid line is the front antenna channel characteristic information CCA at time t2. CCB (t2) indicated by another solid line is rear-side antenna channel characteristic information CCB at time t2.

  The rear-side antenna propagation path characteristic information CCB (t2) shown in FIG. 14B is the propagation path characteristic determined by the rear-side antenna 1372 receiving the reference signal R at the position where the front-side antenna 1371 has received the reference signal R. Information CC. Therefore, the rear antenna channel characteristic information CCB (t2) is similar to the front antenna channel characteristic information CCA (t1). From this, it can be seen that, at time t2, when the base station 1200 and the in-vehicle terminal 1300 communicate with the resource selected by the resource selection unit 1232, communication can be performed with a good SN ratio.

  Further, the resource selection unit 1232 determines resources to be used in the above-described post-timing timing period. As described above, the post-rear timing period is a period after the rear communication timing and before the rear antenna 1372 is predicted to reach the position of the front antenna 1371 at the rear communication timing. FIG. 13C illustrates the position of the in-vehicle terminal 1300 in the post-rear timing period.

  The position of the rear antenna 1372 in FIG. 13C is between the position of the front antenna 1371 at the time t1 shown in FIG. 13A and the position of the front antenna 1371 at the time t2 shown in FIG. . Therefore, as shown in FIG. 14C, the expected value of the rear antenna channel characteristic information CCB (t3) at time t3 is equal to the front antenna channel characteristic information CCA (t1) at time t1 and the front antenna channel characteristic information CCA (t1) at time t2. It can be expected that it is between antenna propagation path characteristic information CCA (t2). The rear antenna channel characteristic information CCB (t3) shown in FIG. 13C is obtained by combining the front antenna channel characteristic information CCA (t1) and the front antenna channel characteristic information CCA (t2) with the front antenna 1371 at time t1. Based on the ratio of the distance from the position to the position of the rear antenna 1372 at time t3 and the distance from the position of the rear antenna 1372 at time t3 to the position of the front antenna 1371 at time t2, the front antenna propagation path characteristic information CCA (t1) and front-side antenna channel characteristic information CCA (t2) can be obtained by weighted averaging. Alternatively, depending on the required accuracy, instead of the weighted average, the front antenna channel characteristic information CCA (t1) and the front antenna channel characteristic information CCA (t2) are simply averaged and the rear antenna channel characteristic information CCB ( t3) may be obtained.

  The resource selection unit 1232 determines the resources to be used in the rear timing post period based on the rear antenna channel characteristic information CCB in the rear timing post period obtained in this way. In the example of FIG. 14C, the expected values of the rear-side antenna channel characteristic information CCB (t3) are such that the frequencies f9 to f10, f11 to f12, and f13 to f14 are in the frequency band where the SN ratio is good. Therefore, frequency channels using these frequency bands are selected as resources used at time t3.

  Then, at time t3, the communication control unit 1234 transmits a signal including the ID of the in-vehicle terminal 1300 using this resource, and communicates with the in-vehicle terminal 1300. Thus, communication can be performed with a good SN ratio even at time t3.

<Fifth embodiment>
The hardware configuration of the mobile communication system of the fifth embodiment is the same as that of the fourth embodiment. The control unit 1330 of the in-vehicle terminal 1300 includes a characteristic information determination unit 1331 and a reception information transmission unit 1332 as in the fourth embodiment.

  However, in the fifth embodiment, the reception information transmitting unit 1332 transmits the current position when the reference signal R is received to the base station 1200 in addition to the various information transmitted in the fourth embodiment. Therefore, in the fifth embodiment, the reception information transmitting unit 1332 includes the front antenna channel characteristic information CCA and the rear antenna channel characteristic information CCB determined from the reference signal R received at the front communication timing and the rear communication timing, respectively. Is transmitted from the transmitting unit 1311 to the base station 1200 together with the moving speed of the on-board terminal 1300 when the reference signal R is received, the distance between the front antenna 1371 and the rear antenna 1372, and the ID of the on-board terminal 300.

  The base station 1200 includes a reproducibility index database 1224 in the storage unit 1220 as shown in FIG. The control unit 1230 further includes a reproducibility determination unit 1235 as shown in FIG. The configuration other than the configuration illustrated in FIG. 15 is the same as that of the base station 1200 of the fourth embodiment, and FIG. 15 omits illustration of the same configuration as the base station 1200 of the fourth embodiment.

  The reproducibility index database 1224 is a database that associates the reproducibility index determined by the reproducibility determination unit 1235 described below with a point.

  The repeatability determining unit 1235 compares the front-side antenna channel characteristic information CCA with the rear-side antenna channel characteristic information CCB determined from the reference signal R transmitted by the base station 1200 at the rear-side communication timing. A reproducibility index indicating the reproducibility of the information CC is determined. The reproducibility index is calculated, for example, as follows. The absolute value of the difference between the S / N ratio indicated by the front antenna channel characteristic information CCA and the S / N ratio indicated by the rear antenna channel characteristic information CCB is calculated at each frequency. It is used as a reproducibility index indicating low reproducibility. Further, the reproducibility determining unit 1235 associates the determined reproducibility index with the communication position, and updates the reproducibility index database 1224 based on the reproducibility index and the communication position.

  Further, in the fifth embodiment, the communication control unit 1234 determines the rear communication timing or the position at the time of communication in the rear timing post period from the current position and the moving speed of the in-vehicle terminal 1300 acquired at the front communication timing. . Then, based on the determined position at the time of communication and the reproducibility index database 1224, a parameter setting relating to communication reliability in a rear communication timing or a period after the rear timing is determined, and communication is performed with the in-vehicle terminal 1300.

  The parameter relating to reliability is, for example, a coding rate. The lower the coding rate, that is, the higher the redundancy, the higher the reliability of communication. Therefore, the smaller the reproducibility index is a value indicating the lower reproducibility, the lower the coding rate. The parameter relating to reliability includes a modulation speed. The higher the modulation speed, the lower the communication reliability. Therefore, the lower the reproducibility index is the lower the reproducibility, the lower the modulation speed.

  Thereby, in the fifth embodiment, the reliability of the communication in the later communication timing or the later timing post period is further improved.

<Sixth embodiment>
The mobile communication system 2000 according to the sixth embodiment includes a first vehicle-mounted terminal 2200 and a second vehicle-mounted terminal 2300 as shown in FIG. The first vehicle-mounted terminal 2200 is mounted on the vehicle 6, and the second vehicle-mounted terminal 2300 is mounted on the vehicle 4. A plurality of each of the first vehicle-mounted terminal 2200 and the second vehicle-mounted terminal 2300 may be provided. The vehicle 6 corresponds to a first mobile unit in the claims, and the first in-vehicle terminal 2200 mounted on the vehicle 6 corresponds to a target communication device in the claims. The vehicle 4 corresponds to the second mobile unit in the claims, and the second in-vehicle terminal 2300 mounted on the vehicle 4 corresponds to the mobile communication device in the claims.

  First, the configuration of the second vehicle-mounted terminal 2300 will be described. As shown in FIG. 17, the second vehicle-mounted terminal 2300 has the same hardware configuration as the vehicle-mounted terminal 1300 of the fourth embodiment.

  Therefore, the communication unit 2310 includes a transmission unit 2311, a reception unit 2312, a front antenna 2371, and a rear antenna 2372. These have the same configuration as the transmitting unit 1311, the receiving unit 1312, the front antenna 1371, and the rear antenna 1372 included in the communication unit 1310 in FIG. Like the front antenna 1371 and the rear antenna 1372, the front antenna 2371 and the rear antenna 2372 are arranged on the roof of the vehicle 4 so as to be in a front-rear relationship with each other in the traveling direction of the vehicle 4 and at the same height. ing. In the sixth embodiment, the front antenna 2371 is a reference antenna, and the rear antenna 2372 is a selected resource antenna.

  Further, storage unit 2320 is the same as storage unit 1320 in FIG. 10, and control unit 2330 includes CPU 2340, ROM 2350, and RAM 2360. The control unit 2330 receives signals from the speed sensor 41 and the position detector 42.

  The function of the control unit 2330 is different from that of the control unit 1330 in FIG. 10, and has the function shown in FIG. That is, control section 2330 has functions as transmission signal generation section 2331 and communication control section 2332.

  The transmission signal generation unit 2331 periodically generates the second terminal signal St2 transmitted from the transmission unit 2311. The second terminal signal St2 includes a reference signal R, a signal indicating the moving speed of the second vehicle-mounted terminal 2300, and a signal indicating the distance between the antennas. The moving speed of the second vehicle-mounted terminal 2300 is the speed acquired from the speed sensor 41. The inter-antenna distance is the distance between the front antenna 2371 and the rear antenna 2372. Note that if first in-vehicle terminal 2200 stores this inter-antenna distance in advance, it is not necessary to include the inter-antenna distance in second terminal signal St2.

  The communication control unit 2332 controls the transmission unit 2211 to transmit the second terminal signal St2 generated by the transmission signal generation unit 2331 from the front antenna 2371. Time t1 shown in FIG. 16A shows this state. When the first terminal 2200 receives the second terminal signal St2, the first terminal 2200 transmits the second terminal signal St2 to the second terminal 2300 using the resource determined based on the reference signal R included in the second terminal signal St2. One terminal signal St1 is transmitted. The communication control unit 2332 controls the receiving unit 2312 to receive the first terminal signal St1 with the rear antenna 2372.

  Next, the configuration of the first vehicle-mounted terminal 2200 will be described. As shown in FIG. 19, the hardware configuration of the first vehicle-mounted terminal 2200 is the same as that of the second vehicle-mounted terminal 2300. That is, the first vehicle-mounted terminal 2200 includes a communication unit 2210, a storage unit 2220, and a control unit 2230. These have the same configuration as the communication unit 2310, the storage unit 2320, and the control unit 2330 included in the second vehicle-mounted terminal 2300.

  The communication unit 2210 includes a transmitting unit 2211, a receiving unit 2212, a target device front antenna 2271, and a target device rear antenna 2272. These have the same configuration as the transmission unit 2311, the reception unit 2312, the front antenna 2371, and the rear antenna 2372 included in the communication unit 2310 of the second vehicle-mounted terminal 2300. The target device front antenna 2271 and the target device rear antenna 2272 are arranged on the roof of the vehicle 6 so as to be in a front-back relationship with each other in the traveling direction of the vehicle 6 and at the same height. The distance between the target device front antenna 2271 and the target device rear antenna 2272 is the same as the distance between the front antenna 2371 and the rear antenna 2372.

  The control unit 2230 includes a CPU 2240, a ROM 2250, and a RAM 2260, and signals from the speed sensor 41 and the position detector 42 are input to the control unit 2230.

  The control unit 2230 has the functions provided in FIG. That is, the control unit 2230 has functions as a characteristic information determination unit 2231, a channel characteristic acquisition unit 2232, a resource selection unit 2233, a timing determination unit 2234, and a communication control unit 2235.

  As described above, the second vehicle-mounted terminal 2300 transmits the second terminal signal St2. When the second terminal signal St2 can be received by the target device front antenna 2271, the characteristic information determination unit 2231 determines that the second vehicle-mounted terminal 2300 is located at the communication position at the time of reception, that is, at the time of transmission for the second vehicle-mounted terminal 2300. Suppose.

  Further, characteristic information determining section 2231 determines channel characteristic information CC based on reference signal R included in received second terminal signal St2. Then, the determined propagation path characteristic information CC is stored in the storage unit 2220. In the present embodiment, the channel characteristic information CC is stored in the storage unit 2220. However, the channel characteristic information CC may be stored in another storage unit. FIG. 21 illustrates the channel characteristic information CC determined by the characteristic information determining unit 2231.

  The channel characteristic acquiring unit 2232 acquires the channel characteristic information CC from the storage unit 2220. The resource selecting unit 2233 selects a resource used for communication at the communication position determined by the characteristic information determining unit 2231 based on the channel characteristic information CC acquired by the channel characteristic acquiring unit 2232. The meaning of the resource and the method of selecting the resource are the same as those of the resource selection unit 235 of the first embodiment. When selecting a frequency resource to be used for communication based on the propagation path characteristic information CC illustrated in FIG. 21, in FIG. 21, the frequencies f15 to f16, f17 to f18, and f19 to f20 are frequency bands with a good SN ratio. Therefore, a frequency channel using these frequency bands is selected as a resource used at a communication position.

  The timing determination unit 2234 predicts the timing at which the rear antenna 2372 included in the second vehicle-mounted terminal 2300 reaches the position where the front antenna 2371 has transmitted the second terminal signal St2, that is, the communication position determined by the characteristic information determination unit 2231. . This timing can be calculated by adding a value obtained by dividing the inter-antenna distance between the rear antenna 2372 and the front antenna 2371 by the moving speed to the reception time of the second terminal signal St2.

  The communication control unit 2235, at the timing determined by the timing determination unit 2234, of the target device front antenna 2271 and the target device rear antenna 2272 on the side closer to the target device front antenna 2271 when the second terminal signal St2 is received. The first terminal signal St1 is transmitted from the antenna to the second vehicle-mounted terminal 2300 using the resource selected by the resource selection unit 2233. There is no particular limitation on the content of the first terminal signal St1. As described above, the second vehicle-mounted terminal 2300 receives the first terminal signal St1 with the rear antenna 2372.

  As a transmission condition under which the communication control unit 2235 transmits a signal at this timing, there is a condition that the moving speed of the second vehicle-mounted terminal 2300 is equal to the moving speed of the first vehicle-mounted terminal 2200. If the moving speed of the second in-vehicle terminal 2300 is not equal to the moving speed of the first in-vehicle terminal 2200, the communication environment when communicating the second terminal signal St2 is similar to the communication environment when communicating the first terminal signal St1. Because it does not become. In addition to the condition that the moving speeds are equal, a condition that the traveling directions are equal or a condition that the vehicle is traveling on the same road may be added.

  The moving speed of the second on-board terminal 2300 is included in the second terminal signal St2, and the moving speed of the first on-board terminal 2200 is determined from the signal of the speed sensor 41 mounted on the vehicle 6. Of course, the expression that the moving speeds are equal includes that they are substantially equal to each other, and up to what speed difference is equal is appropriately set.

  If this transmission condition is not satisfied and the moving speed of either the second vehicle-mounted terminal 2300 or the first vehicle-mounted terminal 2200 is 0 or a low speed close to 0, the moving speed is 0 or a low speed close to 0. Can be handled in the same manner as the base station 1200. Therefore, when the transmission condition is not satisfied, and when the moving speed of either the second in-vehicle terminal 2300 or the first in-vehicle terminal 2200 is 0 or a low speed close to 0, the timing determination unit 2234 and the communication control unit 2235 The same control as the timing determination unit 1233 and the communication control unit 1234 of the fourth embodiment is executed.

  Time t2 shown in FIG. 16B indicates a state in which the timing determined by the timing determination unit 2234 has come. In FIG. 16B, a signal is transmitted from the target device rear antenna 2272. As can be seen by comparing FIG. 16 (A) and FIG. 16 (B), the position of the front antenna 2371 during communication of the second terminal signal St2 and the position of the rear antenna 2372 during communication of the first terminal signal St1 are equal. . In addition, the position of the target device front antenna 2271 at the time of communication of the second terminal signal St2 and the position of the target device rear antenna 2272 at the time of communication of the first terminal signal St1 are also equal. Therefore, the communication environment at the time of communication of the second terminal signal St2 and the communication environment at the time of communication of the first terminal signal St1 are very similar. Therefore, by communicating the first terminal signal St1 using the resource selected based on the channel characteristic information CC determined from the reference signal R included in the second terminal signal St2, the first terminal signal St1 Communication can be performed well.

  In FIG. 16B, as an easy-to-understand example, the positions of the two antennas 2271 and 2371 during communication of the second terminal signal St2 are equal to the positions of the two antennas 2272 and 2372 during communication of the first terminal signal St1. Examples have been given.

  However, since the signal transmission is generally performed at a discrete time period, the communication control unit 2235 cannot transmit the first terminal signal St1 at the strict timing determined by the timing determination unit 2234. In some cases. The “timing determined by the timing determining unit 2234” in the description of the communication control unit 2235 described above means the timing closest to the timing determined by the timing determining unit 2234 among the signal transmission possible timings.

  The timing determined by the timing determination unit 2234 may not coincide with the timing at which a signal can be transmitted. Therefore, at the signal transmittable timing, the target device front antenna 2271 may be closer to the position of the target device front antenna 2271 when the second terminal signal St2 is received than the target device rear antenna 2272. . Therefore, the communication control unit 2235 transmits the first terminal signal St1 to the antenna closer to the target device front antenna 2271 when the second terminal signal St2 is received among the target device front antenna 2271 and the target device rear antenna 2272. It is sent from.

  In the description of the sixth embodiment so far, the functions of the control unit 2230 of the first in-vehicle terminal 2200 and the control unit 2330 of the second in-vehicle terminal 2300 are different for the sake of convenience. However, each of the control units 2230 and 2330 may have both of the functions shown in FIGS. If the second terminal signal St2 has not been received, the function of the control unit 2330 of the second in-vehicle terminal 2300 is executed, and if the second terminal signal St2 has been received, the control unit 2230 of the first in-vehicle terminal 2200 has been executed. Function may be performed.

<Seventh embodiment>
The mobile communication system 3000 according to the seventh embodiment includes a first vehicle-mounted terminal 3200 mounted on the vehicle 4 and a second vehicle-mounted terminal 3300 mounted on the vehicle 6, as shown in FIG. A plurality of each of the first vehicle-mounted terminal 3200 and the second vehicle-mounted terminal 3300 may be provided.

  The first in-vehicle terminal 3200 includes a first antenna 3271, a second antenna 3272, and a third antenna 3273. These antennas 3271, 3272, and 3273 are antennas having the same structure, and are arranged at equal intervals at the same height so as to be in front and rear relation with each other in the traveling direction of the vehicle 6.

  The second in-vehicle terminal 3300 also includes three antennas: a first antenna 3371, a second antenna 3372, and a third antenna 3373. These antennas 3371, 3372, and 3373 are antennas having the same structure as the antennas 3271, 3272, and 3273, and are arranged at equal intervals at the same height so as to be in front and rear relation to each other in the traveling direction of the vehicle 4. ing. The intervals between the antennas 3371, 3372, and 3373 are the same as the intervals between the antennas 3271, 3272, and 3273.

  The hardware configuration of the first in-vehicle terminal 3200 is the same as that of the first in-vehicle terminal in the sixth embodiment except that the first in-vehicle terminal 3200 includes three antennas of a first antenna 3271, a second antenna 3272, and a third antenna 3273 as shown in FIG. 2200 has the same hardware configuration.

  The hardware configuration of the second vehicle-mounted terminal 3300 is the same as that of the second embodiment except that the second vehicle-mounted terminal 3300 includes three antennas, a first antenna 3371, a second antenna 3372, and a third antenna 3373, as shown in FIG. This is the same as the hardware configuration of the vehicle-mounted terminal 2300.

  The control unit 3230 of the first on-board terminal 3200 and the control unit 3330 of the second on-board terminal 3300 have the same function. As shown in FIG. 25, the control unit 3230 of the first vehicle-mounted terminal 3200 includes a characteristic information determination unit 3231, a propagation path characteristic acquisition unit 3232, a timing determination unit 3233, a resource selection unit 3234, a transmission signal generation unit 3235, and a communication control unit. 3236.

  As shown in FIG. 26, the control unit 3330 of the second vehicle-mounted terminal 3300 includes a characteristic information determination unit 3331, a propagation path characteristic acquisition unit 3332, a timing determination unit 3333, a resource selection unit 3334, a transmission signal generation unit 3335, a communication The control unit 3336 is provided.

  In the seventh embodiment, the first vehicle-mounted terminal 3200 functions as a target communication device, and the second vehicle-mounted terminal 3300 functions as a claimed mobile communication device. A state in which the second in-vehicle terminal 3300 functions as the mobile communication device described in the claims and functions as the target communication device in the claims alternates. In the former case, the vehicle 6 corresponds to a first moving body, and the vehicle 4 corresponds to a second moving body. On the other hand, in the latter case, the vehicle 6 corresponds to the second moving body, and the vehicle 4 corresponds to the first moving body.

  As described above, the control unit 3230 of the first in-vehicle terminal 3200 and the control unit 2330 of the second in-vehicle terminal 3300 have the same function, so that only the control unit 3230 of the first in-vehicle terminal 3200 will be described in detail. I do.

  First, the transmission signal generator 3235 will be described. The transmission signal generation unit 3235 generates the estimation signal Sc transmitted from the transmission unit 3311. The estimation signal Sc is a signal similar to the second terminal signal St2 of the sixth embodiment, and is a signal indicating the reference signal R and the moving speed of the vehicle-mounted terminal (here, the first vehicle-mounted terminal 3200) transmitting this signal. And a signal indicating the distance between antennas. The distance between antennas is the distance between the second antenna 3272 and the third antenna 3273. If the second in-vehicle terminal 3300 stores the distance between antennas in advance, it is not necessary to include the distance between antennas in the estimation signal Sc. The estimation signal Sc may be transmitted together with various well-known signals transmitted and received in inter-vehicle communication (hereinafter, this signal). This signal is, for example, a signal for notifying the behavior of the vehicle 4 to the surrounding vehicles, such as an acceleration and a current position.

  The communication control unit 3236 controls the transmission unit 3211 to transmit the estimation signal Sc generated by the transmission signal generation unit 3235 from the second antenna 3272. At this time, the second antenna 3272 functions as a front antenna and a reference antenna. On the other hand, when the second antenna 3372 of the second in-vehicle terminal 3300 transmits the estimation signal Sc, the second antenna 3372 functions as a front antenna and a reference antenna.

  FIG. 22A shows that at time t1, the transmission signal generation unit 3335 and the communication control unit 3326 of the second in-vehicle terminal 3300 execute the same processing as the transmission signal generation unit 3235 and the communication control unit 3236, and the second antenna The state where the estimation signal Sc is transmitted from 3372 is shown. The first in-vehicle terminal 3200 receives the estimation signal Sc with the first antenna 3271, the second antenna 3272, and the third antenna 3273. Note that the reference numerals shown in parentheses in FIG. 22 indicate the reference numerals used in FIG. 27 for each antenna.

  When the estimation signal Sc can be received by the first antenna 3271, the second antenna 3272, and the third antenna 3273, the characteristic information determination unit 3231 transmits the second in-vehicle terminal at the time of reception, ie, at the time of transmission to the second in-vehicle terminal 3300. It is assumed that 3300 is located at the communication position.

  Further, the characteristic information determining unit 3231 determines the channel characteristic information CC based on the reference signal R included in the estimation signal Sc. Then, the determined propagation path characteristic information CC is stored in the storage unit 3220.

  FIG. 27A shows propagation path characteristic information CC determined by characteristic information determining section 3231 based on estimation signal Sc received at time t1. FIG. 27A shows three pieces of propagation path characteristic information CC. The channel characteristic information CCA1-B2 (t1) is the channel characteristic information CC determined by receiving the estimation signal Sc transmitted by the second antenna 3372 by the first antenna 3271. The channel characteristic information CCB1-B2 (t1) is the channel characteristic information CC determined by receiving the estimation signal Sc transmitted by the second antenna 3372 by the second antenna 3272. The channel characteristic information CCC1-B2 (t1) is the channel characteristic information CC determined by receiving the estimation signal Sc transmitted by the second antenna 3372 by the third antenna 3273.

  The channel characteristic acquisition unit 3232 acquires, from the storage unit 3220, three pieces of channel characteristic information CC determined using the signals received by the first antenna 3271, the second antenna 3272, and the third antenna 3273, respectively.

  The timing determination unit 3233 predicts the timing at which the third antenna 3373 included in the second vehicle-mounted terminal 3300 reaches the position where the second antenna 3372 has received the estimation signal Sc, that is, the communication position determined by the characteristic information determination unit 3231. (Ie, pre-determined). This timing can be calculated by adding a value obtained by dividing the distance between the antennas between the second antenna 3372 and the third antenna 3373 by the moving speed to the reception time of the estimation signal Sc.

  The resource selecting unit 3234 selects a resource to be used for communication at the communication position determined by the characteristic information determining unit 3231 based on the three pieces of channel characteristic information CC acquired by the channel characteristic acquiring unit 3232. The meaning of the resource and the method of selecting the resource are the same as those of the resource selection unit 235 of the first embodiment. The resource selecting unit 3234 further uses the moving speed included in the estimation signal Sc, the moving speed of the first vehicle-mounted terminal 3200, and the timing determined by the timing determining unit 3333 when selecting a resource. . From the difference between the two moving speeds, the speed difference between the first vehicle-mounted terminal 3200 and the second vehicle-mounted terminal 3300 can be calculated. This speed difference is multiplied by the time from the current time to the timing determined by the timing determination unit 3333. Thereby, the distance between the first vehicle-mounted terminal 3200 and the second vehicle-mounted terminal 3300 at the timing determined by the timing determination unit 3233 with respect to the distance between the first vehicle-mounted terminal 3200 and the second vehicle-mounted terminal 3300 at the time of communication of the estimation signal Sc. (Hereinafter, a change distance) can be calculated.

  Therefore, at the timing determined by the timing determination unit 3233, the second antenna 3272 compares the first antenna 3271 at the time of receiving the estimation signal Sc by this change distance as compared with when the estimation signal Sc is received. It can be expected that it is located at a position moved in the direction of the third antenna 3273.

Using this prediction, the resource selection unit 3234 determines an expected value of the propagation path characteristic information CC when the second antenna 3272 is used at the timing determined by the timing determination unit 3233. In order to determine the expected value of the propagation path estimation information, two pieces of propagation path characteristic information CC are used. One is propagation path characteristic information CCB1-B2 (t1) corresponding to the second antenna 3272. The other is that the channel characteristic information CCA1-B2 (t1) and the channel characteristic information CCC1-B2
The channel characteristic information CC corresponding to the antenna closer to the second antenna 3272 at the timing determined by the timing determining unit 3233 in (t1). By extrapolating or interpolating these two pieces of propagation path characteristic information CC at, for example, the ratio of the change distance to the inter-antenna distance, the propagation path when the second antenna 3272 is used at the timing determined by the timing determination unit 3233 is shown. The expected value of the characteristic information CC is determined.

  The channel characteristic information CC indicated by a solid line in FIG. 27B is an expected value of the channel characteristic information CCB1-B2 (t2) at time t2, which is the timing determined by the timing determination unit 3233. Also, the dotted lines in FIG. 27B are the three pieces of propagation path characteristic information CC of FIG. 27A shown for comparison. In the predicted value of the propagation path characteristic information CCB1-B2 (t2) shown in FIG. 27B, the moving speed of the first vehicle-mounted terminal 3200 is faster than the moving speed of the second vehicle-mounted terminal 3300. Therefore, at the timing determined by the timing determination unit 3233, as shown in FIG. 22B, the second antenna 3272 moves in the traveling direction of the vehicle 6 more than the first antenna 3271 when the estimation signal Sc is received. It is located forward. Therefore, the expected value of the channel characteristic information CCB1-B2 (t2) is determined by extrapolation using the channel characteristic information CCB1-B2 (t1) and the channel characteristic information CCA1-B2 (t1).

  After determining the expected value of the propagation path characteristic information CCB1-B2 (t2), the communication position is determined using the expected value of the propagation path characteristic information CCB1-B2 (t2) in the same manner as in the sixth embodiment. Select resources to use for communication.

  In addition to generating the above-described estimation signal Sc, the transmission signal generation unit 3235 also generates the estimation signal Sc when a communication position is determined and a resource to be used at the communication position is selected. In addition, the above-mentioned main signal is also generated.

  The communication control unit 3236 transmits the estimation signal Sc and the main signal generated by the transmission signal generation unit 3235 from the second antenna 3272 at the timing determined by the timing determination unit 3233. At this time, the second antenna 3272 functions as a rear antenna of the target device. Further, the first antenna 3271 located before the second antenna 3272 corresponds to a front antenna of the target device.

  The state at the time t2 shown in FIG. 22B indicates this state. Among the estimation signal Sc and the main signal, the reference signal R is allocated to all sub-channels. Other signals are transmitted using the resources selected by the resource selection unit 3234.

  In FIG. 22B, the second vehicle-mounted terminal 3300 receives the estimation signal Sc with the first antenna 3371, the second antenna 3372, and the third antenna 3373. However, at this time, the third antenna 3373 is located at the communication position, and the third antenna 3373 functions as a rear antenna and an antenna for selected resources. The signal received by the third antenna 3373 has high communication reliability.

The characteristic information determining unit 3331 having the same function as the characteristic information determining unit 3231 determines the channel characteristic information CC from the estimation signal Sc received by the first antenna 3371, the second antenna 3372, and the third antenna 3373, respectively. . The position of the second antenna 3372 at the time of reception is defined as a communication position. FIG. 27C illustrates three pieces of propagation path characteristic information CCA2-B1 (t2) and CCB2-B1 determined by the characteristic information determining unit 3331 from the estimation signal Sc received at time t2.
(T2) and CCC2-B1 (t2).

  The propagation path characteristic acquisition unit 3332 acquires the three pieces of propagation path characteristic information CCA2-B1 (t2), CCB2-B1 (t2), and CCC2-B1 (t2) from the storage unit 3320. The timing determination unit 3333 predicts the timing at which the third antenna 3273 included in the first vehicle-mounted terminal 3200 reaches the position where the second antenna 3272 has received the estimation signal Sc, that is, the communication position determined by the characteristic information determination unit 3331. . The predicted timing is set to time t3.

  The resource selecting unit 3334 selects a resource to be used for communication at the communication position determined by the characteristic information determining unit 3331 based on the three pieces of channel characteristic information CC acquired by the channel characteristic acquiring unit 3332. For resource selection, the expected value of propagation path characteristic information CCB2-C1 (t3) shown in FIG. Also in FIG. 27D, the three pieces of propagation path characteristic information CC shown in FIG. 27C are indicated by dotted lines for comparison. Based on the expected value of the propagation path characteristic information CCB2-C1 (t3), the resource used at the communication position is selected.

  The transmission signal generation unit 3335 generates the estimation signal Sc and the main signal. Then, at time t3, the communication control unit 3336 transmits the estimation signal Sc and the main signal from the second antenna 3372. FIG. 22C shows this state. Comparing FIG. 22 (A) and FIG. 22 (C), it can be seen that the state is the same except that the positions of the vehicles 4 and 6 are different. From this, it is understood that in the seventh embodiment, the two-way communication between the first on-board terminal 3200 and the second on-board terminal 3300 can be repeated with high reliability.

<Eighth embodiment>
As shown in FIG. 28, the mobile communication system 4000 according to the eighth embodiment includes a base station 4200 corresponding to a target communication device in the claims and an in-vehicle terminal 4300 corresponding to a mobile communication device in the claims. Each of the base station 4200 and the in-vehicle terminal 4300 may be provided in plurality.

[Configuration of In-Vehicle Terminal 4300]
As shown in FIG. 28, the in-vehicle terminal 4300 includes a plurality of antenna elements 4313. The plurality of antenna elements 4313 are antennas having the same structure as each other, and are arranged on the roof of the vehicle 4 at the same height and periodically.

  These multiple antenna elements 4313 are dynamically assigned to two antennas, a front antenna 4313A and a rear antenna 4313B, by applying the MIMO technology. That is, the front antenna 4313A and the rear antenna 4313B are an antenna element group including a plurality of antenna elements 4313. The front antenna 4313A functions as a reference antenna, and the rear antenna 4313B functions as a selected resource antenna.

  As shown in FIG. 29, the in-vehicle terminal 4300 includes a communication unit 4310, a storage unit 4320, and a control unit 4330. The communication unit 4310 includes a transmission unit 4311 and a reception unit 4312 in addition to the plurality of antenna elements 4313. The transmitting unit 4311 and the receiving unit 4312 perform transmission and reception using a plurality of antenna elements 4313. The transmitting unit 4311 and the receiving unit 4312 have the same functions as the transmitting unit 1311 and the receiving unit 1312 of the fourth embodiment except that a plurality of antenna elements 4313 are used.

  As shown in FIG. 30, the control unit 4330 includes, as functions, a characteristic information determination unit 4331, a communication control unit 4332, and a reception state signal transmission unit 4333.

  First, the characteristic information determining unit 4331 will be described. Also in the eighth embodiment, the base station 4200 periodically transmits the reference signal R. In-vehicle terminal 4300 receives reference signal R with front antenna 4313A and rear antenna 4313B. At this time, the control unit 4330 of the in-vehicle terminal 4300 may determine the antenna elements 4313 constituting the front antenna 4313A and the rear antenna 4313B in advance. Alternatively, the base station 4200 may determine and notify the in-vehicle terminal 4300 together with the reference signal R or prior to the reference signal R.

  The characteristic information determining unit 4331 acquires the reference signal R received by each antenna element 4313 from the receiving unit 4312. Then, for all antenna elements 4313 constituting front antenna 4313A and rear antenna 4313B, channel characteristic information CC between base station 4200 and all antenna elements 4213 used for transmission is determined. The method of determining each channel characteristic information CC may be the same as in the previous embodiments.

  The communication control unit 4332 determines the antenna element 413 used as the front antenna 4313A and the rear antenna 4313B from the plurality of antenna elements 4313, and configures the front antenna 4313A and the rear antenna 4313B. The reference signal R is received by the front antenna 4313A and the rear antenna 4313B. The reason why the rear antenna 4313B also transmits the reference signal R is to determine the reproducibility index. If the reproducibility index is not determined, the rear antenna 4313B does not need to receive the reference signal R.

  Communication control section 4332 uses the moving speed of in-vehicle terminal 4300 and the transmission cycle at which base station 4200 transmits a signal, in order to determine antenna element 4313 to be assigned to front antenna 4313A and rear antenna 4313B. By multiplying the moving speed of the in-vehicle terminal 4300 by the transmission period at which the base station 4200 transmits a signal, the distance that the in-vehicle terminal 4300 moves during one transmission period is calculated.

  The antenna element 4313 is set such that the distance d (hereinafter referred to as “inter-antenna distance”) between the corresponding antenna elements 4313 in the front antenna 4313A and the rear antenna 4313B is equal to or greater than the distance the vehicle-mounted terminal 4300 moves during one transmission cycle. Determine the assignment.

  Further, the antenna element 4313 to be assigned to the front antenna 4313A and the rear antenna 4313B is selected so that the arrangement shapes of the antenna elements 4313 constituting the front antenna 4313A and the rear antenna 4313B are the same.

  This assignment may be determined in advance by the base station 4200 and notified to the in-vehicle terminal 4300. When the in-vehicle terminal 4300 determines this assignment, the transmission cycle in which the base station 4200 transmits a signal is such that the base station 4200 transmits a signal indicating the transmission cycle, and the in-vehicle terminal 4300 receives this signal. Thus, the in-vehicle terminal 4300 can acquire it. Further, the signal transmitted by base station 4200 may be sequentially received and measured. FIG. 31 illustrates an example of assignment of the front antenna 4313A and the rear antenna 4313B. FIG. 32 shows another example of the assignment of the front antenna 4313A and the rear antenna 4313B. In both the example of FIG. 31 and the example of FIG. 32, the arrangement shapes of the antenna elements 4313 forming the front antenna 4313A and the rear antenna 4313B are the same.

  In the example of FIG. 31, the distance d between the antennas is d1, and in the example of FIG. 32, the distance d between the antennas is d2. d2 is shorter than d1. Thus, by changing the assignment of the antenna elements 4313, the distance d between antennas can be changed.

  Receiving state signal transmitting section 4333 transmits receiving state signal Sr from transmitting section 4311 to base station 4200. The reception state signal Sr includes the propagation path characteristic information CC for all combinations of all the antenna elements 4313 and 4213 constituting the front antenna 4313A and the rear antenna 4313B, and the in-vehicle terminal 4300 when the reference signal R is received. Is a signal including the moving speed and the current position of the vehicle, the distance d between the antennas, and the ID of the vehicle-mounted terminal 4300.

  FIG. 28A shows a state in which base station 4200 transmits reference signal R at time t1, and then in-vehicle terminal 4300 transmits reception state signal Sr.

[Configuration of Base Station 4200]
As shown in FIG. 33, base station 4200 includes a plurality of antenna elements 4213 instead of antenna 213 in FIG. The other hardware configuration is the same as that of the base station 200 of the first embodiment, and the base station 4200 includes a communication unit 4210, a storage unit 4220, and a control unit 4230. The communication unit 4210 includes a transmission unit 4211 and a reception unit 4212, and the control unit 4230 includes a CPU 4240, a ROM 4250, and a RAM 4260.

  The storage unit 4220 stores a reproducibility index database 4221 and a road map database 4222. The reproducibility index database 4221 is a database that associates a reproducibility index determined by a reproducibility determination unit 4235 described below with a point.

  As shown in FIG. 34, the control unit 4230 includes, as functions, a channel characteristic acquisition unit 4231, a resource selection unit 4232, a timing determination unit 4233, a communication control unit 4234, and a reproducibility determination unit 4235.

  The propagation path characteristic acquisition unit 4231 acquires, from the reception unit 4212, the propagation path characteristic information CC transmitted by the in-vehicle terminal 4300 and received by the reception unit 4212. Of the acquired channel characteristic information CC, the channel characteristic information CC corresponding to the front antenna 4313A is defined as front antenna channel characteristic information CCA, and the channel characteristic information CC corresponding to the rear antenna 4313B is defined as the rear antenna channel characteristic. Information CCB. It is also assumed that the in-vehicle terminal 4300 is located at the reception position (that is, the communication position) at the time of acquisition. That is, the front antenna propagation path characteristic information CCA and the rear antenna propagation path characteristic information CCB are associated with the communication position.

  The resource selection unit 4232 sets a position where the front antenna 4371A receives the reference signal R as a communication position, and determines a resource used for communication at the communication position based on the front antenna channel characteristic information CCA acquired by the channel characteristic acquiring unit 4231. To decide. The resource selection unit 4232 acquires a reproducibility index corresponding to the position at the time of reception from the reproducibility index database 4221 in addition to the front-side antenna channel characteristic information CCA, and selects a resource using the reproducibility index.

  FIG. 35 illustrates the relationship between the index used by the resource selection unit 4232 to select a resource and the use form of the antenna element 4313. The reproducibility index is a reproducibility index obtained from the reproducibility index database 4221 and corresponding to the position at the time of reception.

  The resource amount whose estimated SN ratio is equal to or higher than the reference is determined from the propagation path characteristic information CC expected at the communication position. The propagation path characteristic information CC expected at the communication position is determined in the same manner as in the fifth embodiment.

  A method of determining a resource amount whose estimated SN ratio is equal to or higher than a reference from the determined channel characteristic information CC may be the same as the method executed in the known MIMO technology. For example, based on propagation path characteristic information, an SNR in each resource when beamforming, diversity coding, spatial multiplexing (multi-stream) or a combination thereof is used is estimated using a known technique, and is estimated to be equal to or higher than a standard. Determine the amount of resources that However, in FIG. 35, for simplicity, only a mode using only one of beamforming, diversity coding, and spatial multiplexing is described. The resource in the “resource amount” has the same meaning as in the embodiments described above. However, in the present embodiment, since the MIMO technology is used, the resources determined by the resource selection unit 4232 include a spatial resource in which the degree of freedom of the determination is generated by the MIMO technology, and the determination of the spatial resource depends on the usage form of the antenna element. It is done by selection.

  The maximum rate is further determined in consideration of the available modulation rate for each resource, that is, the amount of data that can be transmitted per resource. The available modulation rate is determined based on the estimated signal-to-noise ratio, and the method may be the same as the method implemented in known adaptive modulation techniques. In FIG. 35, for simplicity, a value obtained as the rate 1 with respect to the resource amount 3 is shown, which corresponds to a case where all resources estimated to have an SN ratio equal to or higher than the reference are used at the same modulation rate.

  The resource selection unit 4232 selects a resource in the next communication from the index illustrated in FIG. 35 and an index that is important in the next communication. For example, when the reliability of communication is used as an important index, the directivity 2 of a single stream, which is a use form having high reproducibility and having a large amount of resources whose estimated SN ratio is equal to or more than a reference, is determined by using an antenna that determines spatial resources. Select as the form. When the communication speed is used as the important index, the two streams having the highest maximum speed are selected as the antenna use mode. Note that the method of selecting the frequency and time resources is the same as in the previous embodiments.

  The timing determination unit 4233 determines the position of the rear antenna 4313B based on the moving speed of the in-vehicle terminal 4300 received by the reception unit 4212, the rear communication timing at which the front antenna 4313A receives the reference signal R. To determine.

  The communication control unit 4234 periodically transmits the reference signal R from the transmission unit 4211. In addition, at the rear communication timing determined by the timing determining unit 4233, an arbitrary signal is transmitted to the in-vehicle terminal 4300 using the resource selected by the resource selecting unit 4232 as the resource used in the rear communication timing. In addition to this arbitrary signal, the reference signal R is transmitted using all sub-channels as in the fifth embodiment. This communication control unit 4234 corresponds to a target device-side communication control unit in the claims.

  Reproducibility determining section 4235 compares front-side antenna channel characteristic information CCA with rear-side antenna channel characteristic information CCB determined from reference signal R transmitted by base station 4200 at the rear-side communication timing, and determines channel characteristic. A reproducibility index indicating the reproducibility of the information CC is determined. The method of determining the reproducibility index may be the same as that of the reproducibility determining unit 1235 of the fifth embodiment. Further, the reproducibility determining unit 4235 associates the determined reproducibility index with the communication position, and updates the reproducibility index database 4221 based on the reproducibility index and the communication position. The updated reproducibility index database 4221 is used when selecting a resource, as described above.

  As described above, the embodiment of the present invention has been described, but the present invention is not limited to the above-described embodiment, and the following modifications are also included in the technical scope of the present invention. Various changes can be made without departing from the scope.

<Modification 1>
FIG. 3 illustrates the relationship between the frequency and the SN ratio as the propagation path characteristic information CC, but the relationship between the impulse response and the SN ratio may be used instead of the frequency.

<Modification 2>
In the eighth embodiment, the reproducibility index may be determined by comparing the signals sequentially transmitted by the in-vehicle terminal 4300 without providing the reproducibility index database 4221. In this case, the reproducibility index is not an index indicating reproducibility at exactly the same position. However, in the eighth embodiment, a reproducibility index is used to determine a use mode. In this case, even if the reproducibility index is not an index indicating the reproducibility at exactly the same position, the use mode is determined for the time being. This is useful information for In addition, it is not essential to use the reproducibility index to determine the usage mode.

<Modification 3>
In the above-described embodiment, an automobile is shown as a moving body, but another moving body may be used. Other moving objects include rail cars, bicycles, pedestrians, and the like. When the pedestrian holds the mobile communication device, the radio wave propagation map 221 may be created for each of a plurality of predetermined holding states. The holding state is, for example, front holding, pocket storage, or the like. In order to detect these holding states, it is conceivable to equip the mobile communication device with a camera like a smartphone, and to set the state in which the camera can photograph the face of the pedestrian as the front holding state. If the relative movement amount of the mobile communication device is sequentially detected by the acceleration sensor based on the position of the front holding, it is possible to detect which holding state the mobile communication device is in. Further, more simply, the mobile communication device may be provided with a display, instructing the pedestrian of the holding state, and instructing the pedestrian to press the button when the instructed holding state is reached.

<Modification 4>
In the above-described embodiment, the reference signal R is transmitted to determine the channel characteristic information CC. However, transmitting the reference signal R to determine the channel characteristic information CC is not essential. The reference signal R is a signal known on the receiving side. However, if the receiving side returns the receiving state to the transmitting side, the transmitting side determines the propagation path characteristic information CC from the returned receiving state and the transmitted signal because the transmitted signal is known. Can be. In this case, the signal for determining the channel characteristic information CC may be any signal. Therefore, in this case, there is an advantage that overhead due to adding the reference signal R does not occur.

<Modification 5>
The radio wave propagation map 221 may be stored in a server that can communicate with the base station 200.

<Modification 6>
In the first embodiment, the type of the in-vehicle terminal 300 is used as the antenna determination information, and the propagation path characteristic acquiring unit 234 uses the radio wave propagation map 221 for acquiring the propagation path characteristic information CC in the in-vehicle terminal included in the position prediction information. The radio wave propagation map 221 is the same as the model 300. This is because if the model is the same, the antenna characteristics are the same. However, it may be determined whether the antenna characteristics are common depending on the type of the in-vehicle terminal 300. The extent of the difference in antenna characteristics within the common range is determined based on the required performance.

  In the sixth modification, antenna determination information different from the type of the vehicle-mounted terminal 300 is used. Specifically, in the sixth modification, the antenna determination information is the name of the type of the vehicle 4. The vehicle type name may be referred to as a vehicle name. If the in-vehicle terminal 300 is attached when the vehicle 4 is shipped from the factory, the model of the in-vehicle terminal 300 can be specified when the vehicle type name of the vehicle 4 is determined, so that the vehicle type name of the vehicle 4 can be used as antenna determination information. . Since the vehicle type name of the vehicle 4 classifies the vehicle 4, it corresponds to an example of the vehicle classification.

  In the sixth modification, the characteristic determination information upload unit 335 and the position prediction information upload unit 336 included in the vehicle-mounted terminal 300 upload the vehicle type name of the vehicle 4 instead of the model of the vehicle-mounted terminal 300. In order to upload the vehicle type name of the vehicle 4, the storage unit 320 of the vehicle-mounted terminal 300 stores the vehicle type name of the vehicle 4 in advance.

  In the radio wave propagation map 221 provided in the base station 200, the propagation path characteristic information CC is created for each vehicle type name, and the map updating unit 231 updates the radio wave propagation map 221 to be updated based on the vehicle type name of the vehicle 4. Identify. Further, the propagation path characteristic acquisition unit 234 sets the radio wave propagation map 221 for acquiring the propagation path characteristic information CC to be the same as the vehicle type name of the vehicle 4 included in the position prediction information.

<Variation 7>
In the modification 7, a vehicle type classification is used as antenna determination information. The vehicle type classification classifies the types of vehicles based on the similarity of antenna characteristics. When the vehicle type name of the vehicle 4 shown in Modification 6 is used as the antenna determination information, if the vehicle type name of the vehicle 4 is the same, it can be considered that the antenna characteristics are the same. Therefore, there is an advantage that a resource can be selected based on propagation path characteristic information CC having the same antenna characteristic as that of the selected resource antenna. However, it is necessary to have the radio wave propagation map 221 for each vehicle type name.

  The vehicle type classification is a classification for enhancing the versatility of the radio wave propagation map 221 rather than the vehicle type name of the vehicle 4 and is one classification within a range where the antenna characteristics are common. Therefore, the vehicle type classification is a concept wider than the vehicle type name of the vehicle 4 shown in the sixth modification. However, when vehicles are roughly divided, there are concepts such as automobiles and railway vehicles. These are classified according to the social infrastructure on which the vehicle runs. However, the vehicle type classification here is a concept narrower than that of an automobile and a railway vehicle. Specifically, the vehicle type classification is, for example, a passenger vehicle, a bus, which is a concept further classifying an automobile, or a Shinkansen, which is a concept further classifying a railway vehicle, is a specific vehicle type classification. This vehicle type classification may be a classification classified according to the overall height of the vehicle. Note that the vehicle type classification also corresponds to an example of the vehicle classification because the vehicle is classified.

  In the modification 7, the characteristic determination information upload unit 335 and the position prediction information upload unit 336 included in the vehicle-mounted terminal 300 upload the vehicle type classification instead of the model of the vehicle-mounted terminal 300. In order to upload the vehicle type classification, the storage unit 320 of the in-vehicle terminal 300 stores the vehicle type classification in advance.

  In the radio wave propagation map 221 provided in the base station 200, the propagation path characteristic information CC is created for each vehicle type classification, and the map updating unit 231 specifies the radio wave propagation map 221 to be updated based on the vehicle type classification. Further, the propagation path characteristic acquisition unit 234 sets the radio wave propagation map 221 for acquiring the propagation path characteristic information CC to be the same as the vehicle type classification included in the position prediction information.

<Modification 8>
In the modification 8, the installation height of the antenna is used as the antenna determination information. The propagation path characteristics fluctuate with respect to the three-dimensional position. Therefore, the installation height of the antenna is also an antenna characteristic.

  In Modification 8, the characteristic determination information upload unit 335 and the position prediction information upload unit 336 included in the vehicle-mounted terminal 300 are different from the model of the vehicle-mounted terminal 300 in that the installation height of the antenna 313, that is, the installation of the antenna for the selected resource. Upload antenna determination information including height. The installation height of the antenna 313 is stored in the storage unit 320 in advance. The antenna determination information to be uploaded includes the antenna type in addition to the installation height of the antenna for the selected resource, and may include the attitude of the antenna.

  In the radio wave propagation map 221 provided in the base station 200, the propagation path characteristic information CC is created for each reference antenna distinguished based on the antenna determination information. That is, in the radio wave propagation map 221, the propagation path characteristic information CC is created for each installation height of the reference antenna, and is created by being distinguished by other antenna determination information such as an antenna type.

  The map update unit 231 transmits the radio wave propagation map 221 for the reference antenna whose antenna characteristics such as the installation height is the same as that of the antenna 313 to the reception position of the reference signal R uploaded by the characteristic determination information upload unit 335 together with the antenna determination information. Update is performed based on the road characteristic information CC.

  Further, the propagation path characteristic acquisition unit 234 uses the radio wave propagation map 221 for acquiring the propagation path characteristic information CC as the radio wave propagation map 221 determined from antenna determination information other than the antenna installation height included in the position prediction information. Thus, a radio wave propagation map 221 that satisfies the installation height condition is set.

  The installation height condition is a condition that the difference or ratio between the installation height of the antenna 313 and the installation height of the reference antenna included in the position prediction information is within a certain range. When there are a plurality of reference antennas satisfying this condition, the radio wave propagation map 221 corresponding to the reference antenna having the installation height closest to the installation height of the antenna 313 is used as the radio wave propagation map 221 for acquiring the propagation path characteristic information CC. I do.

  In this modified example 8, even if the vehicle types are different, if the antenna characteristics such as the antenna installation height are common, the radio wave propagation map 221 can be shared between different vehicle types. For example, a station wagon with a lower overall height and a sedan-type vehicle with a higher overall height are different types of vehicles, but the antenna installation height may satisfy the above installation height condition. Further, in this modified example 8, the radio wave propagation map 221 having a different antenna installation height can be applied to the same vehicle type for vehicles having a vehicle height adjustment function, such as some off-road vehicles. .

<Modification 9>
In the ninth modification, the holding state of the antenna 313 is used as the antenna determination information. The holding state is, specifically, whether the antenna is fixed or not fixed. The state in which the mobile communication device is not fixed is a state in which the mobile communication device is a portable terminal, and the portable terminal is not held by the holder fixed to the moving body. Whether the object is held by the holder fixed to the moving object is determined based on the acceleration detected by the acceleration sensor provided in the portable terminal. When moving without being held by the holder fixed to the moving body, the change over time of the acceleration detected by the acceleration sensor becomes more complicated than when it is held by the holder. Therefore, it is determined from the time change of the acceleration whether the portable terminal is held by the holder. Further, when the position is not held by the holder fixed to the moving body, the time change of the position becomes more complicated than when the position is held by the holder. Therefore, whether or not the portable terminal is held by the holder may be determined based on the time change of the position.

  In the ninth modification, the characteristic determination information upload unit 335 and the position prediction information upload unit 336 of the mobile communication device change the information indicating whether or not the mobile communication device is fixed, instead of the format of the in-vehicle terminal 300, using the antenna determination. Upload as information. The storage unit 320 of the mobile communication device stores whether the mobile communication device is fixed or mobile. If the mobile communication device is fixed, it is assumed that the mobile communication device is fixed. On the other hand, if the mobile communication device is a portable terminal, it is determined whether or not the mobile communication device is held by a holder fixed to the moving object based on a change in acceleration or position with time.

  Further, the fixed type mobile communication device uploads the fixed part in a held state. The fixed part is also stored in the storage unit 320. The fixed parts are distinguished based on whether or not there is a difference in antenna characteristics. For example, examples of storage of the fixed part include a rooftop, a mirror, a window, and a trunk grid.

  On the other hand, if it is a portable mobile communication device, it is determined whether the mobile communication device is used in a mobile body having a plurality of seats. If it can be determined that the mobile communication device is used in a mobile body having a plurality of seats, it is also determined on which seat the mobile communication device is located.

  Then, information indicating whether or not the mobile communication device is used in a mobile body having a plurality of seats and information on which seat is present are also uploaded as a held state. Whether or not the mobile communication device is used in a mobile body having a plurality of seats and on which seat the mobile communication device is located are determined based on an inquiry to a user who has the mobile communication device.

  The radio wave propagation map 221 provided in the base station 200 has the propagation path characteristic information CC created by distinguishing whether the mobile communication device is a fixed type or a portable type. Are created for each of the above-described fixing portions. On the other hand, for a portable mobile communication device, a radio wave propagation map 221 is created in a case where the mobile communication device is used in a mobile body having a plurality of seats, and is used in a mobile body having a plurality of seats. The radio wave propagation map 221 is created for each existing seat.

  The map updating unit 231 sets the radio wave propagation map 221 to be updated as the radio wave propagation map 221 having the same antenna determination information holding state. Further, the propagation path characteristic acquisition unit 234 sets the radio wave propagation map 221 for acquiring the propagation path characteristic information CC as the radio wave propagation map 221 having the same holding state as the antenna determination information.

<Variation 10>
In the modification 8, in addition to the installation height of the antenna, the antenna type may be used as the antenna determination information. In the ninth modification, the antenna type may be used as the antenna determination information in addition to the holding state.

1: mobile communication system 4: vehicle 5: road 6: vehicle 41: speed sensor 42: position detector 100: mobile communication system 200: base station 210: communication unit 211: transmission unit 212: reception unit 213: antenna 220: storage Unit 221: radio wave propagation map 222: reliability index database 223: road map database 230: control unit 231: map update unit 232: location prediction information acquisition unit 233: location prediction unit 234: propagation path characteristic acquisition unit 235: resource selection unit 236: Communication control unit 237: Reliability updating unit 238: Distance determining unit 239: Characteristic change determining unit 240: Characteristic change compensating unit 300: In-vehicle terminal 310: Communication unit 311: Transmitting unit 312: Receiving unit 313: Antenna 320: Storage Unit 330: control unit 331: position determination unit 332: communication control unit 333: reception control Part 334: transmission control section 335: Characterization uploading unit 336: position prediction uploading unit 337: error resource uploader 338: error detection unit 339: the characteristic data setting section 340: difference determining section 413: antenna element

Claims (25)

A mobile communication device that is used in a mobile object and includes a selected resource antenna (313, 1372, 2372, 3273, 3373, 4313B) for communicating with a selected resource, and performs wireless communication using the selected resource antenna. (300, 1300, 2300, 3300, 4300) and a target communication device (200, 1200, 2200, 3200, 3300, 4200) as a communication target of the mobile communication device. 2000, 3000, 4000)
Propagation path characteristic information, which is information on propagation path characteristics between the reference antenna and the target communication apparatus, in which the antenna characteristic including at least the antenna type is common to the selected resource antenna, is obtained in association with a future communication position. A channel characteristic acquisition unit (234, 1231, 2232, 3232, 3332, 4231);
Based on the propagation path characteristic information acquired by the propagation path characteristic acquisition unit, a resource used for communication between the mobile communication device and the target communication device at the communication position, the selected resource antenna of the mobile communication device is A mobile communication system including a resource selection unit (235, 1232, 2233, 3234, 3334, 4232) for selecting before positioning at the communication position. In claim 1,
A position prediction information acquisition unit (232) for acquiring position prediction information for predicting a position of the selected resource antenna of the mobile communication device;
A position prediction unit (233) for sequentially determining a predicted position of the selected resource antenna based on the position prediction information;
The propagation path characteristic acquisition unit acquires the propagation path characteristic information at the predicted position from a radio wave propagation map (221) which is a database storing the propagation path characteristic information in association with the communication position,
The mobile communication system, wherein the resource selection unit (235) sets the predicted position as the communication position, and selects a resource used for communication between the mobile communication device and the target communication device at the predicted position. In claim 2,
The target communication device is a base station (200),
The base station includes the position prediction information acquisition unit, the position prediction unit, the channel characteristic acquisition unit (234), the resource selection unit, and a storage unit (220) storing the radio wave propagation map,
The radio wave propagation map stores the propagation path characteristic information for a plurality of types of the reference antennas,
The mobile communication device (300) includes a position prediction information upload unit (336) that uploads the position prediction information after the uploading time to the base station together with antenna determination information that can determine the antenna characteristics.
The propagation path characteristic acquisition unit, the communication position is the predicted position predicted by the position prediction unit, and, based on the antenna determination information uploaded from the mobile communication device, determined the reference antenna, determined A mobile communication system for acquiring the propagation path characteristic information determined by the communication position and the reference antenna from the radio wave propagation map. In claim 3,
The moving object is a vehicle,
The position prediction information upload unit, as the antenna determination information, uploads a vehicle classification that classifies the vehicle based on the antenna characteristics when the mobile communication device is used in the vehicle,
The mobile communication system, wherein the propagation path characteristic acquisition unit determines the reference antenna based on the vehicle classification. In claim 4,
The position prediction information upload unit uploads a vehicle type name of the vehicle as the vehicle classification,
The mobile communication system, wherein the propagation path characteristic acquisition unit determines the reference antenna based on a vehicle type name of the vehicle. In claim 4,
The position prediction information upload unit uploads, as the vehicle classification, a vehicle type classification that classifies the vehicle type based on the similarity of the antenna characteristics,
The mobile communication system, wherein the propagation path characteristic acquisition unit determines the reference antenna based on the vehicle type classification. In claim 3,
The moving object is a vehicle,
The position prediction information upload unit, as the antenna determination information, uploads the installation height of the selected resource antenna when the mobile communication device is used in the vehicle,
The mobile communication system, wherein the propagation path characteristic acquisition unit determines the reference antenna based on an installation height of the selected resource antenna and an installation height of the reference antenna. In claim 3,
The location prediction information upload unit uploads the holding state of the selected resource antenna as the antenna determination information,
The mobile communication system, wherein the propagation path characteristic acquisition unit determines the reference antenna based on whether the holding state of the selected resource antenna and the holding state of the reference antenna are the same. In claim 8,
The propagation path characteristic acquisition unit determines whether the holding state of the selected resource antenna and the holding state of the reference antenna are the same, based on whether the selected resource antenna and the reference antenna are both fixed. Mobile communication system to decide. In claim 9,
The propagation path characteristic acquisition unit, in addition to whether the antenna is fixed, when the selected resource antenna and the reference antenna are both fixed, the fixed resource antenna and the fixed part of the reference antenna is A mobile communication system that determines whether the holding state of the selected resource antenna and the holding state of the reference antenna are the same, including whether they are the same. In any one of claims 8 to 10,
The propagation path characteristic acquisition unit, in addition to whether the antenna is fixed, when the selected resource antenna and the reference antenna are not fixed together, the selected resource antenna and the reference antenna are the same seat A mobile communication system that determines whether the holding state of the selected resource antenna and the holding state of the reference antenna are the same, including whether the selected antenna is located above. In any one of claims 3 to 11,
The mobile communication device,
Said reference antenna (313);
A position determining unit (331) for sequentially determining a current position;
A characteristic determination for uploading to the base station the characteristic determination information, which is one of the propagation path characteristic information and the information capable of determining the propagation path characteristic information, together with an upload position that is the latest current position determined by the position determination unit. An information upload unit (335);
The mobile communication system, comprising: a map update unit (231) that updates the radio wave propagation map based on the characteristic determination information uploaded by the mobile communication device and the upload position. In claim 12,
The radio wave propagation map also includes a reliability index indicating reliability for the propagation path characteristic information included in the radio wave propagation map,
The mobile communication system, wherein the resource selection unit selects the resource using the reliability index corresponding to the channel characteristic in addition to the channel characteristic information. In claim 13,
A mobile communication system, wherein the reliability index is a reproducibility index representing reproducibility of the channel characteristic information, which is determined based on a plurality of the channel characteristic information having the same communication position. In claim 13 or 14,
The mobile communication device,
An error detector (337) for detecting an error occurring in the received signal when receiving the signal transmitted by the base station;
An error resource upload unit (336) for uploading error resource information indicating the resource used for transmission of the signal in which the error detection unit has detected an error to the base station;
The base station comprises:
A mobile communication system including a reliability update unit (237) that updates the reliability index based on the error resource information. In any one of claims 12 to 15,
The mobile communication device,
A download data storage unit (320) for storing the radio wave propagation map downloaded from outside;
A characteristic information determining unit (339) for determining the propagation path characteristic information when a signal transmitted by the base station is received by the reference antenna;
Difference between the channel characteristic information determined by the characteristic information determining unit and a portion corresponding to the channel characteristic information determined by the characteristic information determining unit in the radio wave propagation map stored in the download data storage unit. And a difference determining unit (340) for determining a propagation path characteristic difference.
The characteristic determination information upload unit uploads the propagation path characteristic difference as the characteristic determination information,
The mobile communication system, wherein the map updating unit of the base station updates the radio wave propagation map based on the propagation path characteristic difference. In any one of claims 11 to 16,
A distance determining unit (238) for acquiring a moving speed of the mobile communication device and determining a moving distance during a communication period from the acquired moving speed and communication time;
A characteristic change determining unit (239) that determines a change in the propagation path characteristic information during the communication period based on the moving distance determined by the distance determining unit and the radio wave propagation map;
A mobile communication system comprising: a characteristic change compensating unit (240) for performing, on a communication signal, compensation for reducing an influence on communication caused by a change in the propagation path characteristic information during the communication period, determined by the characteristic change determining unit. In claim 1,
The target communication device (1200) sequentially transmits a channel estimation signal,
The mobile communication device (1300) includes a front antenna (1371) and a rear antenna (1372) that are in front and rear relation to each other in the moving direction of the moving body and are the same type of antenna, and refer to the front antenna as described above. Antenna, the rear antenna as the selected resource antenna,
Further, the mobile communication device includes:
A characteristic information determining unit (1331) that determines front antenna channel characteristic information that is the channel characteristic information when the channel estimation signal transmitted by the target communication device is received by the front antenna;
A reception information transmission unit (1332) for transmitting the moving speed of the mobile communication device and the front antenna propagation path characteristic information to the target communication device when the propagation path estimation signal is received by the front antenna,
The target communication device includes the channel characteristic acquisition unit (1231) and the resource selection unit (1232),
The propagation path characteristic acquisition unit acquires the front antenna propagation path characteristic information transmitted by the mobile communication device in association with a position received by a reception unit included in the target communication device,
The resource selection unit, as the communication position the position where the front antenna received the propagation path estimation signal, to select a resource used for communication at the communication position,
Further, the target communication device may include:
Based on the moving speed transmitted by the mobile communication device, a position of the rear antenna determines a rear communication timing that is a timing at which a communication of the propagation path estimation signal by the front antenna is performed. A timing determining unit (1233) to perform
A mobile communication system comprising: a communication control unit (1234) that communicates with the mobile communication device using the resource selected by the resource selection unit at the rear communication timing determined by the timing determination unit. In claim 18,
The timing at which the target communication device transmits the propagation path estimation signal used by the timing determination unit to determine the rear communication timing is a front communication timing,
The communication control unit transmits the propagation path estimation signal at the rear communication timing,
The characteristic information determination unit, in addition to the front antenna channel characteristic information, the propagation path when the propagation path estimation signal transmitted by the target communication device at the rear communication timing is received by the rear antenna Determine the rear antenna propagation path characteristic information that is characteristic information,
The reception information transmitting unit, in addition to the moving speed of the mobile communication device and the front antenna propagation path characteristic information when receiving the propagation path estimation signal at the front communication timing, the propagation path at the front communication timing The current position when the estimation signal is received is also transmitted, and the rear antenna channel characteristic information is also transmitted to the target communication device,
The target communication device,
A reproducibility index database (1224), which is a database that associates a reproducibility index representing the reproducibility of the propagation path characteristic information with a point;
Based on the comparison between the front antenna channel characteristic information and the rear antenna channel characteristic information, determine the reproducibility index for a point corresponding to the front antenna channel characteristic information, and to the determined reproducibility index. A reproducibility determining section (1235) for updating the reproducibility index database based on the reproducibility index database.
The communication control unit, based on the current position and the repeatability index database received together with the front antenna propagation path characteristic information, based on the reliability of communication when transmitting the propagation path estimation signal at the rear communication timing A mobile communication system that determines parameter settings. In claim 1,
The target communication device (2200, 3200) is mounted on a mobile object different from the mobile device using the mobile communication device (2300, 3300),
The mobile unit using the target communication device is a first mobile unit (6), the mobile unit using the mobile communication device is a second mobile unit (4),
The mobile communication device includes a front antenna (2371, 3372) and a rear antenna (2372, 3373) that are in the front-back relationship with each other in the moving direction of the moving body and are the same type of antenna, and the front antenna is As a reference antenna, the rear antenna as the selected resource antenna, from the front antenna, transmitting the moving speed of the second mobile together with a channel estimation signal,
The target communication device,
A channel characteristic acquisition unit (2232, 3232, 3332) and a resource selection unit (2233, 3234, 3334);
The target device front antennas (2271, 3271) and the target device rear antennas (2272, 3272), which are in front and rear relationship with each other in the moving direction of the first mobile body and are the same type of antenna;
When the propagation path estimation signal and the moving speed are received by the target apparatus front antenna, the position of the front antenna when the mobile communication apparatus transmits the propagation path estimation signal is defined as the communication position, A characteristic information determining unit (2231, 3231, 3331) for determining the channel characteristic information based on the determined channel estimation signal, and storing the determined channel characteristic information in a predetermined storage unit;
The propagation path characteristic acquisition unit acquires the propagation path characteristic information at the communication position from the storage unit,
Further, the target communication device may include:
Based on the moving speed received by the target device front antenna, the rear antenna included in the mobile communication device reaches a position where the front antenna included in the mobile communication device has transmitted the propagation path estimation signal. A timing determining unit (2233, 3233, 3333) for determining timing;
At the timing determined by the timing determination unit, of the target device front antenna and the target device rear antenna, from the antenna closer to the target device front antenna when receiving the propagation path estimation signal, A mobile communication system comprising: a communication control unit (2235, 3236, 3336) that performs communication with the rear antenna provided in the mobile communication device using a resource selected by a resource selection unit. In claim 1,
The mobile communication device (4300) includes:
A plurality of antenna elements (4313) arranged periodically and having the same antenna type,
Two antenna element groups including two or more of the antenna elements from among the plurality of antenna elements and arranged in a front-rear relationship with each other in the moving direction of the moving object, wherein an arrangement shape of the antenna elements in the antenna element group Are selected to be the same as each other, and the front antenna element group among the two selected antenna element groups is set as a front antenna (4313A) used as the reference antenna, and the rear antenna element group is selected. A mobile communication system including a communication control unit (4332) that performs communication as a rear antenna (4313B) that uses the selected resource as the selected resource antenna. In claim 21,
The target communication device (4200) sequentially transmits a channel estimation signal,
The mobile communication device,
The front communication path characteristic information, which is the propagation path characteristic information when the propagation path estimation signal transmitted by the target communication apparatus is received by each of the antenna elements constituting the front antenna, A characteristic information determining unit (4331) that determines for each combination of the antenna that has transmitted the propagation path estimation signal and the antenna element that constitutes the front antenna;
The moving speed of the mobile communication device when the propagation path estimation signal is received by the front antenna, the front antenna propagation path characteristic information determined by the characteristic information determination unit, and the front antenna and the rear antenna. A reception state signal transmission unit (4333) for transmitting to the target communication apparatus a distance between antennas representing a distance between the corresponding antenna elements,
The target communication device includes the channel characteristic acquisition unit (4231) and the resource selection unit (4322),
The propagation path characteristic acquisition unit, from the receiving unit provided in the target communication device, the front antenna propagation path characteristic information transmitted by the mobile communication device, to obtain in association with the position at the time of reception,
The resource selection unit, as the communication position the position where the front antenna received the propagation path estimation signal, to select a resource used for communication at the communication position,
Further, the target communication device may include:
Based on the moving speed and the distance between the antennas received from the mobile communication device, the position of the rear antenna is a timing at which the front antenna is at a position where the front antenna receives the propagation path estimation signal. A timing determining unit (4233) for determining timing;
A mobile communication system comprising: a communication control unit (4234) that communicates with the mobile communication device using the resource selected by the resource selection unit at the rear communication timing determined by the timing determination unit. In claim 22,
The communication control unit transmits the propagation path estimation signal at the rear communication timing,
The characteristic information determining unit, the propagation path estimation signal transmitted by the target communication device at the rear communication timing, the rear antenna propagation path characteristic is the propagation path characteristic information when received by the rear antenna The information, the antenna that the target communication device has transmitted the propagation path estimation signal, determined for each combination of the antenna element constituting the rear antenna,
The reception state signal transmission unit transmits the rear antenna propagation path characteristic information to the target communication device,
The target communication device,
The front antenna propagation path characteristic information and the rear antenna propagation path characteristic information are compared for each of the paired antenna elements in the front antenna and the rear antenna, and the propagation path characteristic information at the communication position is obtained. A reproducibility determining unit (4235) for determining a reproducibility index representing the reproducibility of
The resource selection unit selects a resource to be used for communication at the communication position based on the channel characteristic information acquired by the channel characteristic acquisition unit and the reproducibility index determined by the reproducibility determination unit. Mobile communication system. In claim 22 or 23,
The mobile communication device is based on the transmission cycle at which the target communication device transmits a signal and the moving speed of the mobile communication device received by the reception unit included in the target communication device, wherein the distance between the antennas is A mobile communication system in which a plurality of antenna elements are assigned to a front antenna and a rear antenna such that the mobile communication device is longer than a moving distance of the mobile communication device during one transmission cycle. A communication device (200, 1200, 2200, 3200, 3300, 4200) for communicating with a mobile communication device that is used in a mobile object and includes a selected resource antenna for communicating with a selected resource,
Propagation path characteristics in which antenna characteristics including at least an antenna type are propagation path characteristic information that is information on propagation path characteristics between a reference antenna common to the selected resource antenna and the communication device, and the communication position. Acquisition units (234, 1231, 2232, 3232, 3332, 4231);
Based on the propagation path characteristic information acquired by the propagation path characteristic acquisition unit, a resource used for communication between the mobile communication device and the communication device at the communication position, the antenna for the selected resource of the mobile communication device, A communication device comprising: a resource selection unit (235, 1232, 2233, 3234, 3334, 4232) for selecting before positioning at a communication position.

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