Communication system, communication method, interference cancellation device, and interference cancellation program

Abstract

A communication system is provided that can accurately suppress radio interference even when the distance between a wireless communication device of a first wireless communication network and a wireless communication device of a second wireless communication network varies. [Solution] The present invention relates to a communication system comprising two wireless communication systems each having a plurality of wireless communication devices disposed in vehicles or road facilities on a road. The communication system of the present invention is characterized by comprising: means for acquiring a transmission signal of a first wireless communication device; means for acquiring attributes of an interfering signal received by a second wireless communication device due to the transmission signal; and interference signal removal means for performing signal estimation processing to estimate an interference signal component contained in a wireless signal received by the second wireless communication device based on the attributes of the transmission signal and the interference signal, and removing the interference signal component from the wireless signal received by the second wireless communication device based on the result of the signal estimation processing.

Description

[Technical Field]

[0001] The present invention relates to a communication system, a communication method, an interference removal device, and an interference removal program, and can be applied to, for example, wireless communication of a wireless communication device mounted on a vehicle moving on a road. [Background technology]

[0002] Conventionally, when radio wave interference may occur between a plurality of wireless communication networks, there are techniques described in Non-Patent Documents 1 and 2 as techniques for suppressing radio wave interference and performing wireless communication.

[0003] Non-Patent Document 1 describes an "intersystem cooperative interference canceller" that suppresses radio wave interference between the 3.9 GHz band (C band) allocated for fifth-generation mobile communication systems (5G communications), which is the same frequency band as the downlink of earth stations in conventionally used satellite communications. The intersystem cooperative interference canceller in Non-Patent Document 1 is installed on the satellite communications earth station side, and the intersystem cooperative interference canceller described in Non-Patent Document 1 acquires, via wired communication (optical fiber communication), a replica signal branched from a signal transmitted from a 5G base station, and performs processing to remove components of an interference signal (a signal transmitted from a 5G base station and received at an earth station) from a wireless signal (a signal that is a mixture of 5G and radio waves from a satellite) received at the earth station based on the replica signal.

[0004] Non-patent document 2 describes a method for evaluating radio interference from a first wireless system to a second wireless system based on the ratio of carrier power (received power in a steady state) to interference power (carrier power to interference power ratio) when a first wireless system and a second wireless system using the same frequency band exist. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] SoftBank Corp., "System Coordination and Interference Canceller" that suppresses radio wave interference in downlinks between 5G base stations and satellite communication earth stations, [Online], INTERNET, [Retrieved August 3, 2024],<URL:https: / / www.softbank.jp / corp / news / press / sbkk / 2023 / 20231006_01 / > [Non-patent document 2] Nippon Denki Kogyo Co., Ltd., "Radio Wave Lecture for Wireless Systems Doctors, No. 8 Interference Classification and Same Propagation Path Interference, Column, Interference Compensation Technology", [Online], INTERNET, [Retrieved August 3, 2024],<URL: https: / / www.den-gyo.com / innovation / kouza / radio / detail08.php > Summary of the Invention [Problem to be solved by the invention]

[0006] Here, we consider the case where the technologies described in Non-Patent Documents 1 and 2 are applied to suppression of radio wave interference between wireless communication networks in a "road-to-vehicle communication system" in which multiple wireless communication networks are arranged, each comprising a wireless communication device (hereinafter referred to as a "vehicle-side wireless communication device") mounted on a vehicle moving on a road and a wireless communication device (hereinafter referred to as a "roadside infrastructure device") arranged on the road side as infrastructure (road facilities).

[0007] The techniques described in Patent Documents 1 and 2 make it easy to remove interference signals when used in a wireless communication network equipped with a small number of specific, stationary wireless communication devices. However, when wireless communication devices are mounted on vehicles moving at high speed, such as in the above-mentioned road-to-vehicle communication system, the distance between the "interfering side" that causes radio wave interference and the "interfered side" that receives the radio wave interference also fluctuates rapidly, making it difficult to suppress radio wave interference with high precision.

[0008] In view of the above problems, there is a need for a communication system that can accurately suppress radio wave interference even when the distance between a wireless communication device of a first (interfering) wireless communication network and a wireless communication device of a second (interfered) wireless communication network varies. [Means for solving the problem]

[0009] A first communication system of the present invention is a communication system comprising a first wireless communication system having a plurality of first wireless communication devices arranged in vehicles or road facilities on a road, and a second wireless communication system having a plurality of second wireless communication devices arranged in vehicles or road facilities on a road, characterized in that it comprises a transmission signal acquisition means for acquiring a transmission signal of the first wireless communication device, a signal attribute acquisition means for acquiring an attribute of an interfering signal received by the second wireless communication device by the transmission signal, and an interference signal removal means for performing a signal estimation process to estimate a component of the interference signal contained in a wireless signal received by the second wireless communication device based on the attributes of the transmission signal and the interference signal, and removing the component of the interference signal from the wireless signal received by the second wireless communication device based on the result of the signal estimation process.

[0010] The second invention is a communication method performed by a communication system including a first wireless communication system having a plurality of first wireless communication devices arranged in vehicles or road facilities on a road, a second wireless communication system having a plurality of second wireless communication devices arranged in vehicles or road facilities on a road, and an interference removal device that removes interference signal components from the first wireless communication devices from wireless signals received by the second wireless communication devices, characterized in that the communication system has a transmission signal acquisition means, a signal attribute acquisition means, and an interference signal removal means, wherein the transmission signal acquisition means acquires a transmission signal of the first wireless communication device, the signal attribute acquisition means acquires an attribute of the interference signal received by the second wireless communication device from the transmission signal, and the interference signal removal means performs a signal estimation process to estimate the interference signal component included in the wireless signal received by the second wireless communication device based on the transmission signal and the attribute of the interference signal, and removes the interference signal component from the wireless signal received by the second wireless communication device based on the result of the signal estimation process.

[0011] The third aspect of the present invention is an interference removal device constituting a communication system including a first wireless communication system having a plurality of first wireless communication devices arranged in vehicles or road facilities on a road, a second wireless communication system having a plurality of second wireless communication devices arranged in vehicles or road facilities on a road, and an interference removal device that removes interference signal components from the first wireless communication devices from wireless signals received by the second wireless communication devices, the interference removal device being characterized in that it has an interference signal removal means that holds a transmission signal of the first wireless communication device and an attribute of the interference signal received by the second wireless communication device from the transmission signal, performs a signal estimation process to estimate the interference signal component included in the wireless signal received by the second wireless communication device based on the transmission signal and the attribute of the interference signal, and removes the interference signal component from the wireless signal received by the second wireless communication device based on the result of the signal estimation process.

[0012] A fourth interference removal program of the present invention is characterized in that it functions as an interference signal removal means that removes the interference signal components from the first wireless communication devices from the wireless signals received by the second wireless communication devices, and that the computer installed in the interference removal device of the communication system includes a first wireless communication system having a plurality of first wireless communication devices arranged in vehicles or road facilities on a road, a second wireless communication system having a plurality of second wireless communication devices arranged in vehicles or road facilities on a road, and an interference removal device that removes the interference signal components from the first wireless communication devices from the wireless signals received by the second wireless communication devices, by retaining the transmission signal of the first wireless communication device and the attributes of the interference signal received by the second wireless communication device from the transmission signal, performing a signal estimation process that estimates the interference signal components included in the wireless signals received by the second wireless communication device based on the transmission signal and the attributes of the interference signal, and removing the interference signal components from the wireless signals received by the second wireless communication device based on the result of the signal estimation process. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a communication system that accurately suppresses radio interference even when the distance between a wireless communication device of a first wireless communication network and a wireless communication device of a second wireless communication network varies. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram showing an overall configuration of a communication system according to a first embodiment. [Figure 2] 1 is a block diagram showing the functional configuration of each device constituting a communication system according to a first embodiment. [Figure 3] FIG. 10 is a diagram (part 1) showing a specific example of an estimated value of the amount of interference by the interference amount estimation means according to the first embodiment. [Figure 4] FIG. 10 is a diagram (part 2) showing a specific example of an estimated value of the amount of interference by the interference amount estimation means according to the first embodiment. [Figure 5] FIG. 10 is a diagram (part 3) showing a specific example of an estimated value of the amount of interference by the interference amount estimation means according to the first embodiment. [Figure 6] FIG. 10 is a diagram (part 4) showing a specific example of an estimated value of the amount of interference by the interference amount estimation means according to the first embodiment. [Figure 7] 5 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the first embodiment. [Figure 8] 4 is a flowchart showing the operation of the interference removal device of the wireless communication system according to the first embodiment. [Figure 9] 4 is a flowchart showing the operation of the interference management device according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an overall configuration of a communication system according to a second embodiment. [Figure 11] FIG. 10 is a block diagram showing the functional configuration of each device constituting a communication system according to a second embodiment. [Figure 12] FIG. 10 is a block diagram showing the functional configuration of each device constituting a communication system according to a third embodiment. [Figure 13] 10 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the third embodiment. [Figure 14] 10 is a flowchart showing the operation of an interference removal device in the wireless communication system according to the third embodiment. [Figure 15] FIG. 10 is a block diagram showing the functional configuration of each device constituting a communication system according to a fourth embodiment. [Figure 16] 10 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the fourth embodiment. [Figure 17] 10 is a flowchart showing the operation of the interference management device according to the fourth embodiment. [Figure 18] FIG. 10 is a diagram showing the overall configuration of a communication system according to a fifth embodiment. [Figure 19] FIG. 10 is a block diagram showing the functional configuration of each device constituting a communication system according to a fifth embodiment. [Figure 20]13 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the fifth embodiment. [Figure 21] FIG. 13 is a block diagram showing the functional configuration of each device constituting a communication system according to a sixth embodiment. [Figure 22] 13 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the sixth embodiment. [Figure 23] 13 is a flowchart showing the operation of an interference removal device in the wireless communication system according to the sixth embodiment. [Figure 24] FIG. 13 is a block diagram showing the functional configuration of each device constituting a communication system according to a seventh embodiment. [Figure 25] 13 is a flowchart showing the operation of a wireless communication device in its own wireless communication system according to the seventh embodiment. [Figure 26] 13 is a flowchart showing the operation of an interference removal device in the wireless communication system according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] (A) First embodiment A first embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described below in detail with reference to the drawings.

[0016] (A-1) Configuration of the First Embodiment FIG. 1 is a block diagram showing the overall configuration of a communication system 1 according to the first embodiment.

[0017] As shown in FIG. 1, the communication system 1 has a first wireless communication system, ie, a local wireless communication system 10, and a second wireless communication system, ie, another wireless communication system 20, which is located in the same area as the local wireless communication system 10 or in the surrounding area (a location where interference of radio waves due to wireless communication may occur).

[0018] The local wireless communication system 10 includes roadside infrastructure 130, which is infrastructure equipment installed on a road, wireless communication devices 110 (110-0, 110-1, 110-2, ...) as first wireless communication devices installed in each of vehicles 120 (120-1, 120-2, ...) traveling on the road, and an interference management device 140 that manages radio wave interference (hereinafter simply referred to as "interference") with communication of another wireless communication system 20 through wireless communication of each wireless communication device 110. In this embodiment, the interference management device 140 is a device to which the information processing device (information processing program) of the present invention is applied. In this embodiment, it is assumed that the wireless communication device 110-0 is installed in the roadside infrastructure 130, and the vehicles 120-1, 120-2, ... are equipped with wireless communication devices 110-1, 110-2, ..., respectively. The local wireless communication system 10 is capable of wireless communication between the roadside infrastructure 130 (wireless communication device 110-0) and each vehicle 120 (wireless communication devices 110-1, 110-2, ...) (hereinafter referred to as "road-to-vehicle communication"), or wireless communication between any combination of each vehicle 120 (wireless communication devices 110-1, 110-2, ...) (hereinafter referred to as "vehicle-to-vehicle communication"). Note that each wireless communication device 110 may be configured to be capable of serial communication using multi-hop wireless communication or the like. Note that the local wireless communication system 10 of this embodiment will be described as an environment in which road-to-vehicle communication and vehicle-to-vehicle communication coexist, but it may also be configured as an environment in which only road-to-vehicle communication or only vehicle-to-vehicle communication exists. Note that each wireless communication device 110 needs to be able to communicate with the interference management device 140 via some communication path. Note that when only vehicle-to-vehicle communication is performed, the wireless communication device 110-0 of the roadside infrastructure 130 is excluded.

[0019] The other wireless communication system 20 has a wireless communication device 210-0 as a second wireless communication device mounted on a roadside infrastructure 230, and wireless communication devices 210 (210-1, 210-2, ...) mounted on each vehicle 220 (220-1, 220-2, ...). In the other wireless communication system 20, an interference removal device 240 is connected to or mounted on the roadside infrastructure 230 to remove radio wave interference in the wireless communication device 210-0 (radio wave interference (interference signal) from the wireless communication device 110 of the own wireless communication system 10). In this embodiment, the other wireless communication system 20 may also perform road-to-vehicle communication and vehicle-to-vehicle communication in any combination, similar to the own wireless communication system 10.

[0020] In this embodiment, the wireless communication device 210 and the interference removal device 240 are described as separate devices (hardware) and connected by wire (various wired interfaces), but the wireless communication device 210 and the interference removal device 240 may also be integrated into one piece of hardware.

[0021] The interference management device 140 communicates with each wireless communication device 110 to exchange information about interference with other wireless communication systems 20. There are no limitations on the location or place where the interference management device 140 is installed. For example, the interference management device 140 may be installed in a management center that manages the system, or may be installed on the cloud (on the Internet).

[0022] Furthermore, the communication means / path between the interference management device 140 and each wireless communication device 110 is not limited, and various configurations can be applied. For example, each wireless communication device 110 may be provided with a means for connecting to a mobile communication network (e.g., a mobile phone network of a communication carrier) and connected to the interference management device 140 via the mobile communication network. Furthermore, if multi-hop wireless communication is possible within the own wireless communication system 10, each vehicle 120 (wireless communication devices 110-1, 110-2, ...) may communicate with the interference management device 140 via the roadside infrastructure 130 (wireless communication device 110-0). In this case, the interference management device 140 needs to be able to communicate with the roadside infrastructure 130 (wireless communication device 110-0) via various communication means (e.g., various wired / wireless networks, etc.). A plurality of interference management devices 140 may be arranged in the own wireless communication system 10. When a plurality of interference management devices 140 are arranged in the own wireless communication system 10, the interference management devices 140 may be configured to manage each of the interference management devices in a predetermined area. In the following explanation, it is assumed that there is one interference management device 140 in the local wireless communication system 10, but even if there are multiple interference management devices, the same concept as in the case of one device can be applied.

[0023] Next, the relationship between the own wireless communication system 10 and the other wireless communication system 20 will be described.

[0024] Here, it is assumed that the local wireless communication system 10 and the other wireless communication system 20 use the same or adjacent frequency bands. Therefore, radio waves emitted by a wireless communication device of one system may interfere with a wireless communication device of the other system. Therefore, in order to share both systems, it is desirable to prevent interference between them (a situation does not arise in which interference from one system prevents the wireless communication of the other system from satisfying a predetermined communication quality). For example, when the local wireless communication system 10 is newly introduced in a situation in which the other wireless communication system 20 is already in operation, it is required that the local wireless communication system 10 be operated so as not to cause interference with the other wireless communication system 20, which is an existing wireless system. For this reason, an interference removal device 240 is connected to the wireless communication device 210-0 of the other wireless communication system 20, and interference signals from the local wireless communication system 10 to the other wireless communication system 20 are removed.

[0025] In the first embodiment, it is assumed that the wireless communication device 110-0 (roadside infrastructure 130) of the own wireless communication system 10 and the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20 are connected via a communication path 400. That is, in the first embodiment, when the wireless communication device 110 of the own wireless communication system 10 is mounted on a roadside infrastructure, information about interference of the own wireless communication system 10 (for example, information about a transmission signal, etc.) is supplied to the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20 via the communication path 400. There are no particular limitations on the specific communication method of the communication path 400, and it is also possible to use, for example, a wired communication network using a dedicated line or a mobile communication network (for example, a wireless communication network of a mobile phone). On the other hand, when the wireless communication device 110 of the own wireless communication system 10 is mounted on a vehicle, there are two possible methods for supplying information about interference of the own wireless communication system 10 (for example, information about transmission signals, etc.) to the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20: relaying the information through the roadside infrastructure 130 (wireless communication device 110-0) of the own wireless communication system 10 and supplying it to the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20 (hereinafter referred to as the method of supplying to roadside infrastructure by relay communication), and supplying it directly to the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20 (hereinafter referred to as the method of supplying to roadside infrastructure by direct communication). In the case of the method of supplying to roadside infrastructure by relay communication, the communication between the roadside infrastructure 130 (wireless communication device 110-0) of the own wireless communication system 10 and the other mobile communication network (for example, a wireless communication network of a mobile phone) may be used, and the communication between the roadside infrastructure 130 (wireless communication device 110-0) and the wireless communication device 210-0 (roadside infrastructure 230) of the other wireless communication system 20 may be a wired communication network with a dedicated line or a mobile communication network (for example, a wireless communication network of a mobile phone) on the communication path 400. On the other hand, in the case of the method of supplying to roadside infrastructure by direct communication, communication may be performed via a mobile communication network (for example, a wireless communication network of a mobile phone).

[0026] In this embodiment, the interference removal device 240 is connected to or installed only in the wireless communication device 210-0 of the roadside infrastructure 230, but the interference removal device 240 may also be connected to or installed in at least one of the wireless communication devices 210 of the vehicle 220, and the interference removal device 240 does not necessarily have to be connected to or installed in the wireless communication device 210-0 of the roadside infrastructure 230. When an interference removal device 240 is connected to or installed in the wireless communication device 210 of the vehicle 220, possible methods for supplying information regarding interference in the own wireless communication system 10 (for example, information regarding transmission signals, etc.) to the vehicle 220 (wireless communication device 210) include relaying the information through at least one of the roadside infrastructure 130 (wireless communication device 110-0) of the own wireless communication system 10 and the roadside infrastructure 230 (wireless communication device 210-0) of the own wireless communication system 20 and supplying it to the vehicle 220 (wireless communication device 210) of the other wireless communication system 20 (hereinafter referred to as the method of supplying to the vehicle by relay communication), and supplying it directly to the vehicle 220 (wireless communication device 210) (hereinafter referred to as the method of supplying to the vehicle by direct communication). In the case of the method of supplying to vehicles by relay communication, the vehicle 120 (wireless communication device 110) of the own wireless communication system 10 and the roadside infrastructure 130 (wireless communication device 110-0) of the own wireless communication system 10 may use wireless communication of the own system or another mobile communication network (for example, a wireless communication network of a mobile phone), and the roadside infrastructure 230 (wireless communication device 210-0) of the other wireless communication system 20 and the vehicle 220 (wireless communication device) of the other wireless communication system 20 may use wireless communication of the other system or another mobile communication network (for example, a wireless communication network of a mobile phone). On the other hand, in the case of the method of supplying to vehicles by direct communication, communication may be performed via a mobile communication network (for example, a wireless communication network of a mobile phone).

[0027] Next, an example of the configuration of each device that configures the communication system 1 will be described with reference to FIG.

[0028] FIG. 2 is a block diagram showing an example of the functional configuration of devices constituting the own wireless communication system 10 (wireless communication device 110, radio wave interference control unit 300) and devices constituting the other wireless communication system 20 (wireless communication device 210 and interference removal device 240).

[0029] The wireless communication device 110 has a wireless communication unit 101 for wireless communication and a radio wave interference control unit 300 that controls radio wave interference. The wireless communication unit 101 has an antenna 1011 for transmitting and receiving radio waves, a demodulation processing means 1012 that demodulates the radio waves captured by the antenna 1011 to obtain a signal (baseband signal) superimposed on a carrier wave, and a modulation processing means 1013 that modulates the signal (baseband signal) to be transmitted wirelessly so that it is superimposed on a carrier wave. The radio wave interference control unit 300 may be installed in all of the wireless communication devices 110 or only in some of the wireless communication devices 110. In this embodiment, it is assumed that the radio wave interference control unit 300 is installed in at least the wireless communication device 110-0 of the roadside infrastructure 130.

[0030] The radio wave interference control unit 300 has a transmission signal acquisition means 301, a signal attribute acquisition means 303, an interference information providing means 302, an interference amount acquisition means 304, an interference attribute acquisition means 305, an interference status providing means 306, and an interference amount acquisition means 307.

[0031] The interference removal device 240 includes an interference information acquisition means 241 , an interference signal acquisition means 242 , and an interference signal removal means 243 .

[0032] The interference management device 140 includes an interference state acquisition unit 141 , an interference amount estimation unit 143 , and an interference amount providing unit 142 .

[0033] The wireless communication device 210 has a wireless communication unit 201 for performing wireless communication. The wireless communication unit 201 has an antenna 2011 for transmitting and receiving radio waves, a demodulation processing means 2012 for demodulating the radio waves captured by the antenna 2011 to acquire a signal (baseband signal) carried on a carrier wave, and a modulation processing means 2013 for modulating the signal to be wirelessly transmitted (baseband signal) so that it is carried on a carrier wave and emitting it from the antenna 2011 as a radio wave.

[0034] It is also assumed that the demodulation processing means 2012 of the wireless communication unit 201 and the interference cancellation device 240 are connected by wire (connected by various wired interfaces). For example, the interference cancellation device 240 may be connected so as to acquire a signal received by the antenna 2011 (waveform after demodulation by the demodulation processing means 2012), process the acquired signal (interference cancellation processing), and return it to the demodulation processing means 2012.

[0035] The transmission signal acquisition means 301 acquires a transmission signal from the wireless communication device 110 of its own wireless communication system 10 (an interference signal to the wireless communication device 210 of the other wireless communication system 20), and provides it to the interference information providing means 302. Examples of the format of the transmission signal from the wireless communication device 110 include a bit string before encoding and modulation, or a baseband signal sequence (I phase and Q phase) after encoding and modulation quantized for each sampling frequency. In the wireless communication device 110 of this embodiment, it is possible to acquire the transmission signal from the transmission circuit (modulation processing means 1013) of the wireless communication unit 101.

[0036] The signal attribute acquiring means 303 acquires attributes (hereinafter also referred to as "interference attributes" or simply "attributes") of the transmission signal of the wireless communication device 110 of its own wireless communication system 10 (interfering signal to the wireless communication device 210 of the other wireless communication system 20), and provides the attributes to the interference information providing means 302. Examples of the attributes of the transmission signal of the wireless communication device 110 of its own wireless communication system 10 (interfering signal to the wireless communication device 210 of the other wireless communication system 20) include, for example, the interference start time on the interfered side of the transmission signal and the carrier frequency difference of the transmission signal of the wireless communication device 110 (interfering side) of its own wireless communication system 10. The interference start time on the interfered side of the transmission signal can be realized, for example, by each wireless communication device 110 (interfering side) of its own wireless communication system 10 being equipped with time acquiring means such as a GNSS (Global Navigation Satellite System) and acquiring the time at which the transmission signal radio wave started to be sent. In this case, the interference removal device 240 connected to the wireless communication device 210 (interfered side) of the other wireless communication system 20 needs to add the propagation delay of the radio wave from the interfering side to the interfered side to the time when the transmission signal radio wave starts to be sent in order to obtain the interference start time on the interfered side. It is possible to consider the propagation delay as 0, but to obtain a more accurate value, if the position of the interfering side and the position of the interfered side (own device) can be obtained from information on the interfering side, it can be estimated from the distance between the interfering side and the interfered side.

[0037] The wireless communication device 110 (interfering side) of the own wireless communication system 10 may be provided with a demodulation circuit (demodulation circuit of the other wireless communication system 20) for receiving and demodulating radio waves emitted by the wireless communication device 210 (interfered side) of the other wireless communication system 20, and may estimate the carrier frequency difference of the transmission signal of the wireless communication device 110 (interfering side) (the difference between the carrier frequency of the transmission signal in the wireless communication device 110 (interfering side) and the carrier frequency of the reception signal in the wireless communication device 210 (interfered side)) based on the radio waves received by the demodulation circuit. For example, in the wireless communication device 110 of its own wireless communication system 10, it is possible to estimate the difference between the carrier frequency of the received signal in the demodulation circuit of the other wireless communication system 20 and the carrier frequency of the transmitted signal in the wireless communication device 210 (interfered side) of the other wireless communication system 20, and further add a frequency deviation (the difference between the reference value of the carrier frequency and the carrier frequency of the received signal in the demodulation circuit of the other wireless communication system 20, which occurs due to the characteristics of the demodulation circuit (e.g., a crystal device constituting the demodulation processing means 2012) of the wireless communication device 110 (interfering side)) that has been set in advance by measurement, etc. Note that the method for estimating the carrier frequency difference (the difference between the carrier frequency of the transmission signal in the wireless communication device 110 (interfering side) and the carrier frequency of the reception signal in the wireless communication device 210 (interfered side)) in the wireless communication system 10 itself is not limited, and various methods can be applied. Also, in the wireless communication device 110, when the transmission signal contains a repetition of a signal sequence, the carrier frequency difference may be estimated by a method of calculating a phase difference between symbols corresponding to the repetition of the signal sequence in the reception signal, and dividing the averaged value by the length of the repetition interval.Furthermore, in the wireless communication device 110, if there is no repetition of the signal sequence in the transmitted signal, the phase difference between each symbol of the received signal and each symbol of a signal (replica of the transmitted signal) obtained by encoding and modulating a bit sequence obtained by demodulating and decoding the received signal may be calculated, and further, for all symbols except the first symbol in the signal sequence, the difference between the phase difference at a certain symbol and the phase difference at the previous symbol may be calculated, and the above-mentioned carrier frequency difference may be estimated by averaging the calculated phase differences.

[0038] The interference information providing means 302 provides the interference information acquisition means 241 with the transmission signal (interference signal to the wireless communication device 210 of the other wireless communication system 20) of the wireless communication device 110 of the own wireless communication system 10 acquired from the transmission signal acquisition means 301, the attribute of the transmission signal of the wireless communication device 110 of the own wireless communication system 10 acquired from the signal attribute acquisition means 303, and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 acquired from the interference amount acquisition means 307 (hereinafter referred to as "amount of interference").

[0039] The interference information acquisition means 241 provides the interference signal removal means 243 with the transmission signal of the wireless communication device 110 of the own wireless communication system 10 (interference signal to the wireless communication device 210 of the other wireless communication system 20) acquired from the interference information providing means 302, the attributes of the transmission signal of the wireless communication device 110 of the own wireless communication system 10, and the amount of interference to the wireless communication device 210 of the other wireless communication system 20.

[0040] In this embodiment, the interference information providing means 302 of the wireless communication device 110-0 mounted on the roadside infrastructure 130 and the interference information acquiring means 241 of the interference removal device 240 mounted on the roadside infrastructure 230 can be realized by an interface (for example, a general-purpose data communication modem, etc.) connected to the communication path 400. The interference information providing means 302 of the wireless communication device 110 mounted on the vehicle 120 in the own wireless communication system 10 can communicate with the interference information acquiring means 241 of the interference removal device 240 from the wireless communication unit 101 of the own device via the roadside infrastructure 130 (wireless communication device 110-0) and the communication path 400. Furthermore, when communication is performed between the wireless communication device 110 mounted on the vehicle 120 in the own wireless communication system 10 and the interference removal device 240 using another mobile communication network, for example, a general-purpose data communication modem, etc. can be applied to the interference information providing means 302 of the wireless communication device 110 mounted on the vehicle 120 and the interference information acquiring means 241 of the interference removal device 240.

[0041] The interference signal acquisition means 242 acquires a received signal (the received signal is interfered with by a transmission signal (interference signal) transmitted from the wireless communication device 110 of the own wireless communication system 10) received from another wireless communication device 210 by the wireless communication device 210 (wireless communication unit 201) to which the own device is connected, and provides the received signal to the interference signal removal means 243.

[0042] The interference signal removal means 243 estimates a component of the own system transmission signal (hereinafter also referred to as an "interfered interference signal") received by the wireless communication device 110 of the other wireless communication system 20, based on the transmission signal (hereinafter also referred to as an "own system transmission signal" or an "interference signal to another system") transmitted by the wireless communication device 110 of the own wireless communication system 10 supplied from the interference information acquisition means 241. Then, the interference signal removal means 243 extracts the signal transmitted by the other wireless communication device 210 (hereinafter also referred to as a "desired signal") and the signal received by the wireless communication device 210 (i.e., a signal from which the interference signal has been removed; hereinafter also referred to as an "interference-removed reception signal") by subtracting the estimated value of the "interfered interference signal" from the reception signal from the interference signal acquisition means 242 (the signal received by the wireless communication device 210 of the other wireless communication system 20; hereinafter also referred to as a "reception signal including the interfering interference signal" or an "interference-removed reception signal").

[0043] In the interference signal removal means 243, to estimate the above-mentioned "interfered interference signal," a process (hereinafter referred to as "first correction process") is performed to correct the local system transmission signal (transmission signal of the wireless communication device 110 of the local wireless communication system 10) based on the attributes of the local system transmission signal (for example, the above-mentioned carrier frequency difference), and further a process (hereinafter referred to as "second correction process") is performed to correct the amount of interference (estimated value of the amount of interference) to the wireless communication device 210 of the other wireless communication system 20.

[0044] For example, the above-mentioned carrier frequency difference (the difference between the carrier frequency of the transmission signal of the wireless communication device 110 of the wireless communication system 10 itself and the carrier frequency of the reception signal of the wireless communication device 210 (interfered side)) may be applied as the attribute used in the first correction process (correction process based on the attribute). In this case, the interference signal removal means 243 performs a process of generating a replica of a signal sequence in which a phase fluctuation amount reflecting the carrier frequency difference is added to each symbol of the baseband signal sequence after encoding and modulation quantized for each sampling frequency in the first correction process, and acquires this generated replica.

[0045] Furthermore, for example, a value equivalent to the received power of radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20 in the wireless communication device 110 of the own wireless communication system 10 (for example, a received signal strength indicator (RSSI) that quantifies the received power) may be applied as the amount of interference (an estimated value of the amount of interference) used in the second correction process. In this case, the interference signal removal means 243 may generate a replica of a signal sequence obtained by multiplying the amplitude of each symbol of the result of the first correction process (a signal sequence obtained by correcting the transmission signal of the wireless communication device 110 of the own wireless communication system 10 based on the attribute of the transmission signal of the own wireless communication system 10; hereinafter, also referred to as "a transmission signal sequence corrected based on the signal attribute") by a coefficient proportional to the square root of the received power, and acquire the generated replica.

[0046] Furthermore, for example, the phase difference (amount of phase fluctuation) between the transmission signal by the wireless communication device 210 of the other wireless communication system 20 and the reception signal at the wireless communication device 110 of the wireless communication system 10 may be applied as the amount of interference (estimated value of the amount of interference) used in the second correction process. In this case, the interference signal removal means 243 may generate a replica of the signal sequence by adding the amount of phase fluctuation to the result of the first correction process (each symbol of the transmission signal sequence corrected based on the attribute), and acquire the replica.

[0047] Furthermore, for example, a delay profile (for example, a combination of delay times and received powers of direct waves and delayed waves) in the wireless communication device 110 of the wireless communication system 10 of radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20 may be applied as the amount of interference (an estimated value of the amount of interference) used in the second correction process. In this case, the interference signal removal means 243 may generate a replica of the signal sequence by multiplying the amplitude of the result of the first correction process (each symbol of the transmission signal sequence corrected based on the signal attribute) by a coefficient proportional to the square root of the received power for each delay time in the delay profile, and obtain the replica as the result of the second correction process.

[0048] When performing the process of subtracting the estimated value of the "interfered interference signal" from the "interfered received signal" (hereinafter also simply referred to as "subtraction process"), the interference signal removal means 243 may subtract, for each symbol of the signal sequence of the interfering received signal, the value of each symbol in the estimated value of the interfering interference signal corresponding to the same time as the signal sequence of the interfering received signal based on the attribute of the transmission signal of the own wireless communication system 10 (for example, the start time of interference on the interfered side of the transmission signal), or may perform subtraction between complex numbers when the value of each symbol is a complex number quantized with the I phase as the real part and the Q phase as the imaginary part, or may correct the attribute of the transmission signal of the own wireless communication system 10 (for example, the start time of interference on the interfered side of the transmission signal) by calculating the cross-correlation of the interfering received signal using the estimated value (signal sequence) of the interfering interference signal as a reference signal.

[0049] Furthermore, during the subtraction process, the interference signal removal means 243 may correct the estimated value of the "interfered interference signal" and then subtract the value of each symbol in the estimated value of the interfering interference signal corresponding to the same time as the signal series of the interfering received signal (for example, if the value of each symbol is a complex number quantized with the I phase as the real part and the Q phase as the imaginary part, subtraction between complex numbers). Furthermore, the interference signal removal means 243 can calculate the cross-correlation to correct the attributes of the transmission signal of its own wireless communication system 10 (for example, the start time of interference on the interfered side of the transmission signal) by repeatedly multiplying signal sequences within the interval of the signal sequence of the reference signal while shifting the start time of the signal sequence of the estimated value (reference signal) of the interfered interference signal for each predetermined time step within a predetermined time before and after the start time of interference on the interfered side of the transmission signal, and select the time at which the cross-correlation is maximized (for example, if the values ​​of each symbol of both the interfered received signal and the estimated value of the interfered interference signal are complex numbers quantized with the I phase as the real part and the Q phase as the imaginary part, the value of the cross-correlation at each time is also a complex number (the result of converting one of the signal sequences into a conjugate complex number and multiplying them), so the time at which the absolute value of the cross-correlation is maximized is selected). Furthermore, to correct the estimated value of the mixed interference signal by calculating the cross-correlation, the interference signal removal means 243 corrects the value of each symbol of the estimated value of the mixed interference signal by the difference between the calculated value of the cross-correlation and the value of the cross-correlation when both signal sequences to be cross-correlated match. For example, when the value of each symbol of both the interfering received signal and the estimated value of the interfering signal is a complex number quantized with the I phase as the real part and the Q phase as the imaginary part, the value of cross-correlation at each time is also a complex number (the result of converting one of the signal sequences into a complex conjugate and multiplying them), the interfering signal removal means 243 multiplies each symbol of the signal sequence of the estimated value (reference signal) of the interfering signal by (absolute value of cross-correlation) / (average value of amplitude in the signal sequence of the estimated value (reference signal) of the interfering signal), and further when the estimated value (reference signal) of the interfering signal is converted into a complex conjugate and multiplied, the interfering signal removal means 243 multiplies each symbol of the signal sequence of the estimated value (reference signal) of the interfering signal by the argument of cross-correlation (adding the phase of each symbol by the argument of cross-correlation).

[0050] Furthermore, when a plurality of local system transmission signals (interference signals to the wireless communication device 210 of the other wireless communication system 20) are present at the same time and the interference signal removal means 243 subtracts the estimated values ​​of the plurality of interfering signals from the interfering received signal, it may subtract all of the estimated values ​​of the interfering signals, or it may subtract a predetermined number of the estimated values ​​of the interfering signals from the plurality of interfering signal estimates in descending order of the average value (average power) of the squared amplitude of each symbol in the signal sequence (the remaining estimated values ​​of the interfering signals with small average powers do not need to be subtracted because they are smaller than the average power of the desired signal and can be ignored).

[0051] The interference amount acquisition means 304 receives radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20, acquires the amount of interference from the wireless communication device 210 of the other wireless communication system 20, and provides it to the interference status providing means 306.

[0052] In this embodiment, examples of the amount of interference (amount of interference from a wireless communication device of another wireless communication system 20) include a value equivalent to the received power of radio waves transmitted by a wireless communication device of another wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10 (such as RSSI, which quantifies the received power), the phase difference (amount of phase fluctuation) between the transmitted signal by the wireless communication device of the other wireless communication system 20 and the received signal at the wireless communication device 110 of the own wireless communication system 10, and the delay profile of radio waves transmitted by a wireless communication device of the other wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10 (for example, a combination of the delay time and received power of the direct wave and delayed wave).

[0053] For example, it is assumed that the interference amount acquisition means 304 sets the interference amount (amount of interference from a wireless communication device of the other wireless communication system 20) as a value (RSSI or the like that quantifies the received power) equivalent to the received power in the wireless communication device 110 of its own wireless communication system 10 of the radio wave transmitted by the wireless communication device of the other wireless communication system 20. In this case, if the wireless communication unit 101 (demodulation processing means 1012) of the wireless communication device 110 is equipped with a demodulation circuit (hereinafter referred to as the "demodulation circuit of the other system") that can receive and demodulate the radio wave transmitted from the wireless communication device 210 of the other wireless communication system 20, the interference amount acquisition means 304 can acquire the value equivalent to the received power based on the signal demodulated by the wireless communication unit 101 (demodulation circuit of the other system) of its own device. In addition, in this embodiment, the wireless communication device 110 (wireless communication unit 101) is equipped with a demodulation circuit of another system, so that it is possible to match the band of the radio waves emitted by the wireless communication device 210 of the other wireless communication system 20 with the receiving band, and to distinguish the radio waves emitted by the wireless communication device 210 of the other wireless communication system 20 from other noise.In this case, it is possible to obtain a more accurate value for the amount of interference from the wireless communication device of the other wireless communication system 20, and to eliminate erroneous detection caused by other noise.

[0054] Also, for example, it is assumed that the interference amount acquisition means 304 regards the amount of interference (amount of interference from a wireless communication device of another wireless communication system 20) as the phase difference (amount of phase fluctuation) between a signal transmitted by the wireless communication device of another wireless communication system 20 and a signal received by the wireless communication device 110 of its own wireless communication system 10. In this case, the wireless communication unit 101 (demodulation processing means 1012) of the wireless communication device 110 needs to receive the radio waves emitted by the wireless communication device 210 of the other wireless communication system 20 and include a circuit for demodulating and decoding the radio waves, and a circuit for encoding and modulating the demodulated and decoded bit string. In this case, the interference amount acquisition means 304 may calculate, for all symbols, the phase difference between each symbol in the received signal of the radio waves emitted by the wireless communication device 210 of the other wireless communication system 20 and each symbol in a signal (a replica of the transmitted signal) obtained by encoding and modulating the bit string obtained by demodulating and decoded the received signal, and take the average.

[0055] Furthermore, for example, it is assumed that the interference amount acquisition means 304 uses the delay profile (combination of delay times and received powers of direct waves and delayed waves) of radio waves transmitted by a radio communication device of the other radio communication system 20 in the radio communication device 110 of its own radio communication system 10 as the interference amount (amount of interference from a radio communication device of the other radio communication system 20). In this case, the radio communication device 110 (radio communication unit 101) needs to receive the radio waves transmitted by the radio communication device of the other radio communication system 20 and include a circuit for demodulating and decoding the radio waves and a circuit for encoding and modulating the demodulated and decoded bit string. In this case, the interference amount acquisition means 304 may calculate cross-correlation using, as a reference signal, a signal sequence (replica of a transmitted signal sequence) obtained by encoding and modulating a bit string obtained by demodulating and decoded the received signal, for the received signal sequence of the radio waves transmitted by the radio communication device of the other radio communication system 20.

[0056] The interference attribute acquisition means 305 acquires an attribute of the amount of interference received from a wireless communication device of another wireless communication system 20 (hereinafter referred to as "interference attribute") and provides the attribute to the interference status providing means 306. An example of the interference attribute is the position (hereinafter referred to as "reception position") of the own device (wireless communication device of the own wireless communication system 10). Information on the interference attribute such as the reception position can be acquired by a positioning system such as GNSS, and in a system in which a wireless communication device is intended to be mounted on a vehicle, such as the own wireless communication system 10, a positioning system is often already provided in the vehicle in order to notify each other of their positions by wireless communication, and therefore this information can be reused.

[0057] Furthermore, as another example of the interference attribute, the position of the wireless communication device of the other wireless communication system 20 that transmitted the radio wave (hereinafter referred to as "transmission position") may be added in addition to the reception position.

[0058] When the wireless communication devices 210 of the other wireless communication systems 20 notify each other of their positions by wireless communication and when the wireless communication device 110 of the own wireless communication system 10 includes a demodulation circuit of the other wireless communication system 20, it is possible to acquire information on the transmission position. As another example of the interference attribute, in addition to the reception position, a value equivalent to the antenna height of the own device (the wireless communication device of the own wireless communication system 10) (hereinafter referred to as "receiving antenna height") may be added. The information on the receiving antenna height is information equivalent to the height of the antenna 1011 of the wireless communication device of the own wireless communication system 10 or the height of the antenna. For example, when the wireless communication device 110 is mounted on a vehicle, it is considered that the antenna is mounted on the roof of the vehicle to improve visibility, so information equivalent to the antenna height includes the vehicle height or the vehicle model. The information on the receiving antenna height is stored in the wireless communication device 110 (radio wave interference control unit 300). Alternatively, when the own wireless communication system 10 is a system intended for the wireless communication device 110 to be mounted on a vehicle, it is assumed that the wireless communication devices 110 will notify each other of their vehicle attributes by wireless communication, and since the vehicle is often already equipped with means for acquiring this information, it can be reused.

[0059] As another example of interference attributes, when there is a transmitting position in addition to the receiving position, a value equivalent to the antenna height of the wireless communication device of the other wireless communication system 20 that transmitted the radio waves (hereinafter referred to as "transmitting antenna height") may be added in addition to the above information. The information on the transmitting antenna height is the height of the antenna 2011 of the wireless communication device 210 of the other wireless communication system 20 or information equivalent to the height of the antenna 2011. In the other wireless communication system 20, when the wireless communication device 210 is mounted on a vehicle, the antenna 2011 may be mounted on the roof of the vehicle 220 to improve visibility. Therefore, the information equivalent to the height of the antenna 2011 may be the vehicle height or the vehicle type. The antenna height information may be stored in the radio wave interference control unit 300 in advance, or, in the case of a system in which the other wireless communication system 20 is intended to mount the wireless communication device 210 on the vehicle 220, it is assumed that the wireless communication devices 210 will notify each other of their vehicle attributes by wireless communication (including notifying the vehicle 120 of the own wireless communication system 10 (wireless communication device 110)). Since the vehicle 220 is often already equipped with a means for acquiring this information, the information on the antenna height can be reused.

[0060] The interference status providing means 306 provides the interference status acquisition means 141 with the amount of interference from the wireless communication device 210 of the other wireless communication system 20 acquired from the interference level acquisition means 304 and the interference attribute acquired from the interference attribute acquisition means 305. The interference status acquisition means 141 provides the interference level from the wireless communication device 210 of the other wireless communication system 20 acquired from the interference status providing means 306 and the interference attribute to the interference level estimation means 143. As described above, the communication means for providing information from the wireless communication device 110 to the interference management device 140 is not particularly limited, but when a mobile phone wireless communication network is used, the interference status providing means 306 and the interference status acquisition means 141 can be realized by a general-purpose data communication modem or the like.

[0061] The interference amount estimation means 143 acquires an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 based on the amount of interference received from the wireless communication device of the other wireless communication system 20 and the interference attributes previously acquired from a large number of wireless communication devices 110 of the own wireless communication system 10, and provides the estimate to the interference amount providing means 142.

[0062] Here, the following equation (1) holds for interference from the wireless communication device 210 of the other wireless communication system 20 (each term in the equation is in decibels): Here, R0 is the received power of the radio wave transmitted by the wireless communication device 210 of the other wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10, P1 is the transmission power of the wireless communication device 210 of the other wireless communication system 20, A1 is the transmitting antenna gain of the wireless communication device 210 of the other wireless communication system 20, F1 is the loss due to the transmitting feeder line and the like of the wireless communication device 210 of the other wireless communication system 20, L is the propagation loss, T0 is the receiving antenna gain of the wireless communication device 110 of the own wireless communication system 10, and J0 is the loss due to the receiving feeder line and the like of the wireless communication device 110 of the own wireless communication system 10. R0=P1+A1-F1-L+T0-J0 (1)

[0063] On the other hand, with regard to interference to the wireless communication device 210 of the other wireless communication system 20, the following equation (2) holds (each term in the equation is in decibels): Here, R1 is the received power of the radio wave transmitted by the wireless communication device 110 of the own wireless communication system 10 at the wireless communication device 210 of the other wireless communication system 20, P0 is the transmission power of the wireless communication device 110 of the own wireless communication system 10, A0 is the transmitting antenna gain of the wireless communication device 110 of the own wireless communication system 10, F0 is the loss due to the transmitting feeder line and the like of the wireless communication device 110 of the own wireless communication system 10, L is the propagation loss, T1 is the receiving antenna gain of the wireless communication device 210 of the other wireless communication system 20, and J1 is the loss due to the receiving feeder line and the like of the wireless communication device 210 of the other wireless communication system 20. R1=P0+A0-F0-L+T1-J1 (2)

[0064] L in equations (1) and (2) is the same because only the direction of transmission and reception is different between the same wireless communication devices. Therefore, the interference amount acquisition means 304 provides R0 to the interference amount estimation means 143 as the amount of interference from the wireless communication device 210 of the other wireless communication system 20, and the interference amount estimation means 143 can calculate L from equation (1) when P1, A1, F1, T0, and J0 are known or can be acquired from information transmitted by related wireless communication devices, etc. Furthermore, when P0, A0, F0, T1, and J1 are known or can be acquired from information transmitted by related wireless communication devices, etc., it is possible to estimate R1 as the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from equation (2).

[0065] The interference amount estimation means 143 has previously acquired the amount of interference received from a wireless communication device of another wireless communication system 20 from a large number of wireless communication devices 110 of its own wireless communication system 10, and since L is expected to be the same when the position (transmission position) of the wireless communication device 210 of the other wireless communication system 20 and the position (reception position) of the wireless communication device of its own wireless communication system 10 are the same, it is possible to improve the accuracy of L, which was a problem in the conventional technology, by smoothing the large number of values ​​of L when the transmission position and the reception position are the same and obtaining an estimated value. As a result, it is possible to more accurately estimate R1, which is the amount of interference given to the wireless communication device 210 of the other wireless communication system 20.

[0066] In this embodiment, an example of the amount of interference from a wireless communication device of another wireless communication system 20 has been described as being a value equivalent to the received power of radio waves transmitted by a wireless communication device of another wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10 (such as RSSI, which quantifies the received power). However, an example of the amount of interference from a wireless communication device 210 of another wireless communication system 20 may also be the phase difference (amount of phase fluctuation) between the transmitted signal by the wireless communication device 210 of the other wireless communication system 20 and the received signal at the wireless communication device 110 of the own wireless communication system 10, or the delay profile (a combination of delay time and received power of the direct wave and delayed wave) of radio waves transmitted by a wireless communication device of another wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10.

[0067] Even in this case, the phase difference (amount of phase fluctuation) between the transmission signal in the wireless communication device 210 of the other wireless communication system 20 and the reception signal in the wireless communication device 110 of the own wireless communication system 10, and the phase difference (amount of phase fluctuation) between the transmission signal in the wireless communication device 110 of the own wireless communication system 10 and the reception signal in the wireless communication device 210 of the other wireless communication system 20 can be considered to be the same, since only the transmission and reception directions are different between the same wireless communication devices. Furthermore, the delay profile of the radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20 in the wireless communication device 110 of the own wireless communication system 10, and the delay profile of the radio waves transmitted by the wireless communication device 110 of the own wireless communication system 10 in the wireless communication device 210 of the other wireless communication system 20 can also be considered to be the same, since only the transmission and reception directions are different between the same wireless communication devices.

[0068] Furthermore, when the position (transmission position) of the wireless communication device of the other wireless communication system 20 and the position (reception position) of the wireless communication device of the own wireless communication system 10 are the same, it is expected that the phase difference (phase fluctuation amount) or the delay profile will be the same, and therefore, by smoothing the values ​​of the many phase differences (phase fluctuation amounts) or the delay profiles when the transmission position and the reception position are the same to obtain estimated values, it becomes possible to improve accuracy and more accurately estimate the amount of interference to the wireless communication device 210 of the other wireless communication system 20. Details of the method for calculating the estimated value of the amount of interference will be described later.

[0069] The interference amount providing means 142 provides the interference amount acquisition means 307 with the estimated value of the amount of interference to the wireless communication device in the other wireless communication system 20, acquired from the interference amount estimation means 143. The interference amount acquisition means 307 provides the interference information providing means 302 with the estimated value of the amount of interference to the wireless communication device 210 in the other wireless communication system 20, acquired from the interference amount providing means 142. As described above, the communication means for providing information from the interference management device 140 to the wireless communication device 110 is not particularly limited, but when a mobile phone wireless communication network is used, the interference amount providing means 142 and the interference amount acquisition means 307 can be realized by a general-purpose data communication modem.

[0070] The method of calculating the estimated value of the amount of interference in the interference amount estimation means 143 will be described in detail with reference to FIGS.

[0071] 3 to 6 are diagrams showing specific examples of how the interference amount estimation means 143 obtains an estimated value of the interference amount.

[0072] Here, as an example of the amount of interference from a wireless communication device of another wireless communication system 20, we will explain the case where the amount is a value equivalent to the received power of radio waves transmitted by a wireless communication device of another wireless communication system 20 at the wireless communication device 110 of the own wireless communication system 10 (such as RSSI, which quantifies the received power). However, the same applies to the case where the amount of interference is the phase difference (amount of phase fluctuation) between the transmitted signal by the wireless communication device of the other wireless communication system 20 and the received signal at the wireless communication device 110 of the own wireless communication system 10, or the delay profile (a combination of delay time and received power of the direct wave and delayed wave) at the wireless communication device 110 of the own wireless communication system 10 of radio waves transmitted by a wireless communication device of the other wireless communication system 20 (the "propagation loss" in this explanation should be read as the above-mentioned "phase difference (amount of phase fluctuation)" or the above-mentioned "delay profile").

[0073] The interference amount estimation means 143 acquires and stores the amount of interference and interference attribute from the wireless communication device of the other wireless communication system 20 as an interference state from the wireless communication device 110 of its own wireless communication system 10 (interference state providing means 306) via the interference state acquisition means 141. When the interference amount estimation means 143 stores the interference state (amount of interference and interference attribute), it may store the interference state as a structure. As explained above in the interference attribute acquisition means 305, examples of the interference attribute include the receiving position, transmitting position, receiving antenna height, and transmitting antenna height. In Fig. 4, an example of a structure indicating the interference state is illustrated as data D1.

[0074] The interference amount estimation means 143 may acquire an interference attribute different from the interference attribute acquired from the wireless communication device 110 of its own wireless communication system 10. An example of the interference attribute is the density of wireless communication devices of its own wireless communication system 10 around the receiving position (hereinafter referred to as "terminal density around the receiving position"). One example of a method for storing the terminal density around the receiving position is as a column vector (hereinafter referred to as "terminal density vector around the receiving position") having the same number of elements as the number of areas (hereinafter referred to as "regional meshes") obtained by dividing the range in which wireless communication devices of its own wireless communication system 10 may exist into meshes of a predetermined size.

[0075] The interference amount estimation means 143 acquires the terminal density around the receiving position in the regional mesh including the receiving position from the receiving position included in the stored interference state (for example, in the terminal density vector around the receiving position described above, reads out the element of the row number corresponding to the regional mesh including the receiving position). Also, in order to calculate the terminal density around the receiving position, the interference amount estimation means 143 counts the number of terminals within a predetermined time for each regional mesh including the receiving position (for example, each time an interference state acquired from the wireless communication device 110 of the own wireless communication system 10 is saved within a predetermined time, the number of terminals in the regional mesh including the receiving position is increased (incremented) by 1. When the wireless communication device 110 of the own wireless communication system 10 transmits periodically, it is desirable that the predetermined time be an integer multiple of the transmission period so as to prevent an error in the terminal density around the receiving position).

[0076] Here, each regional mesh is assigned a number (identifier; hereinafter referred to as "regional mesh number") of 0, 1, 2, ..., N2-1. Also, here, each time series within a given observation period is assigned a number (identifier; hereinafter referred to as "time series number") of 0, 1, 2, ..., M2-1. Note that the smaller the time series number, the earlier the time series.

[0077] Figure 3 shows data D2 as an example of a matrix for calculating the terminal density around a receiving terminal. In the matrix of data D2, regional mesh numbers corresponding to the receiving position are assigned as row numbers, and time series numbers within a specified observation time are assigned as column numbers. In the matrix of data D2, a count value of the number of terminals is set for each cell (for each combination of regional mesh number and time series number).

[0078] The interference level estimation means 143 may perform smoothing by accumulating the terminal density around the receiving position within a predetermined time. When a simple moving average is used as the smoothing method, for example, the data is stored in memory as a matrix in which the rows represent the regional meshes containing the receiving position and the columns represent the time series. In this case, the number of rows is the number of regional meshes, the number of columns is the number of accumulated terminal densities around the receiving position within a predetermined time (the time for performing the moving average), and it is assumed that the column direction is implemented as a ring buffer. Other applicable smoothing methods include weighted moving averages, exponential moving averages, percentiles (moving medians in the case of the 50th percentile), and methods using other smoothing filters.

[0079] 3 and 4, data D4 is illustrated as a vector (a vector indicating the terminal density around the receiving position) smoothed for each area mesh number for the matrix of data D2. In the vector of data D4, a smoothed count value is set for each area mesh number corresponding to the receiving position.

[0080] Another example of the interference attribute, when the interference attribute includes the transmission position, is the density of wireless communication devices of other wireless communication systems 20 around the transmission position (hereinafter referred to as "terminal density around the transmission position"). The calculation method and realization means for the terminal density around the transmission position are the same as those for the terminal density around the reception position, so details will be omitted.

[0081] FIG. 3 shows data D3 as an example of a matrix for calculating the terminal density around a transmitting terminal. In the matrix of data D3, regional mesh numbers corresponding to the transmission position are assigned as row numbers, and time series numbers within a predetermined observation time are assigned as column numbers. In the matrix of data D3, a count value of the number of terminals is set for each cell (for each combination of regional mesh number and time series number). Also, in FIGS. 3 and 4, data D5 is shown as a vector (a vector indicating the terminal density around the transmission position) smoothed for each regional mesh number in the matrix of data D3. In the vector of data D5, a smoothed count value is set for each regional mesh number corresponding to the transmission position.

[0082] The interference amount estimation means 143 calculates the path loss by the method described above from the amount of interference received from the wireless communication device of the other wireless communication system 20 included in the interference state. As described above, by smoothing a large number of path loss values ​​to obtain an estimated value when the transmitting position and the receiving position are the same (for simplicity of explanation, it is said that the transmitting position and the receiving position are the same, but more precisely, the interference attribute included in the interference state including the amount of interference received from the wireless communication device 210 of the other wireless communication system 20 corresponding to the calculated path loss and, if acquired by the interference amount estimation means 143, at least one attribute combination (hereinafter referred to as "tally key") is similar from the interference attribute different from the interference attribute acquired from the wireless communication device 110 of the own wireless communication system 10), it is possible to improve the accuracy of the path loss, which was a problem in the conventional technology. Therefore, it is necessary to divide the large number of path loss values ​​into groups by similar tally keys, accumulate the path losses for each group with similar interference attributes, and smooth them. The interference amount estimation means 143 then generates a counting key, groups the calculated propagation losses, and smooths the propagation losses to obtain estimated values.

[0083] Next, the interference amount estimation means 143 estimates the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from the estimated values ​​of propagation loss belonging to the group determined by the aggregation key using the method described above, and provides the amount of interference to the wireless device of the other wireless communication system 20 to the wireless communication device 110 of the own wireless communication system 10 (interference amount acquisition means 307) via the interference amount providing means 142.

[0084] When the aggregation key includes the receiving position and the transmitting position, it is possible to group the propagation loss by receiving position and transmitting position, thereby improving the estimation accuracy after smoothing. When the aggregation key includes the receiving position but not the transmitting position, the estimation accuracy after smoothing is lower than when the aggregation key includes the receiving position and the transmitting position. However, including the receiving position improves the estimation accuracy compared to smoothing without grouping. When the aggregation key includes the receiving antenna height in addition to the receiving position, there is a correlation between antenna height and propagation loss (higher antenna heights tend to have better visibility and be less affected by obstructions, resulting in smaller propagation loss), so the estimation accuracy after smoothing is improved compared to when the aggregation key does not include the receiving antenna height. For the same reason, when the aggregation key includes the transmitting antenna height in addition to the transmitting position, the estimation accuracy after smoothing is also improved. When the tally key includes the terminal density around the reception position in addition to the reception position, there is a correlation between the terminal density around the reception position and the propagation loss (the higher the terminal density around the reception position, the denser the terminals (wireless communication devices 110 of the own wireless communication system 10) are, and the more susceptible to the influence of obstruction by objects carrying the terminals (for example, large vehicles if the terminals are mounted on vehicles), and the greater the propagation loss tends to be), so the estimation accuracy after smoothing is improved compared to when the tally key does not include the terminal density around the reception position.For the same reason, when the tally key includes the terminal density around the transmission position in addition to the transmission position, the estimation accuracy after smoothing is also improved.

[0085] For example, when generating and saving a tally key, the interference level estimation means 143 may store it in memory as a structure, and the interference attributes included in the tally key (receiving position or transmitting position or receiving antenna height or transmitting antenna height or terminal density around the receiving position or terminal density around the transmitting position) may each be quantized with a predetermined resolution. If the tally key includes the receiving position, transmitting position, receiving antenna height, transmitting antenna height, terminal density around the receiving position, and terminal density around the transmitting position, and there are N1, N2, N3, N4, N5, and N6 possible quantized values ​​for each, then N = N1 × N2 × N3 × N4 × N5 × N6, where N1, N2, N3, N4, N5, and N6 are all integers greater than or equal to 1.

[0086] In this embodiment, the receiving position i1 is assumed to be an integer (quantized value) between 0 and N1-1, the transmitting position i2 is assumed to be an integer (quantized value) between 0 and N2-1, the receiving antenna height i3 is assumed to be an integer (quantized value) between 0 and N3-1, the transmitting antenna height i4 is assumed to be an integer (quantized value) between 0 and N4-1, the terminal density i5 around the receiving position is assumed to be an integer (quantized value) between 0 and N5-1, and the terminal density i6 around the transmitting position is assumed to be an integer (quantized value) between 0 and N6-1. As described above, the receiving position i1 and the transmitting position i2 correspond to the above regional mesh numbers. Furthermore, the values ​​(quantized values) of the receiving antenna height i3 and the transmitting antenna height i4 are assumed to have corresponding ranges of dimensions. For example, for the receiving antenna height i3 and the transmitting antenna height i4, less than 50 cm may be set to "0", 50 cm or more but less than 100 cm to "1", 100 cm or more but less than 150 cm to "2", ... Furthermore, for each value (quantized value) of the terminal density i5 around the receiving position and the terminal density i6 around the transmitting position, it is assumed that a corresponding range of density is set.

[0087] In Fig. 4, data D6 is illustrated as an example of a structure indicating a counting key. The counting key structure shown in Fig. 4 includes six items as interference attributes: receiving position, transmitting position, receiving antenna height, transmitting antenna height, terminal density at the receiving position, and terminal density at the transmitting position.

[0088] One example of a method for retaining (storing in memory, etc.) the estimated value of propagation loss as a column vector (hereinafter referred to as "estimated value vector of propagation loss") having the same number of elements as the number of possible combinations of values ​​of the aggregation key. In Fig. 6, an example of the estimated value vector of propagation loss is shown as data D9. In data D9, the estimated value of propagation loss corresponding to each aggregation number (0 to N-1) is set.

[0089] The interference amount estimation means 143 acquires the estimated value of the propagation loss corresponding to the value of the aggregation key from the stored estimated values ​​of the propagation loss (for example, in the propagation loss estimated value vector described above, it reads out the element of the row number (hereinafter referred to as "aggregation number") corresponding to the value of the aggregation key. The correspondence between the value of the aggregation key and the aggregation number must be determined in advance, and one example is a method of storing a correspondence table of the value of the aggregation key and the aggregation number in memory). In the following, it is assumed that 0 to N-1 is assigned as the aggregation number for each combination of aggregation keys.

[0090] 5 shows data D7 as an example of a correspondence table between the values ​​of the tally keys and the tally numbers. In Fig. 5, a tally number is assigned to each combination of six items that make up the tally key.

[0091] Furthermore, when calculating the estimated value of the propagation loss, the interference level estimation means 143 performs smoothing by accumulating the propagation loss within a predetermined time. If a simple moving average is used as the smoothing method, for example, the data is stored in memory as a matrix with the row direction representing the aggregation number and the column direction representing the time series. In this case, the number of rows represents the number of aggregation key combinations, the number of columns represents the number of accumulated propagation losses within a predetermined time (the time for performing the moving average), and the column direction is assumed to be implemented as a ring buffer. Other applicable smoothing methods include weighted moving averages, exponential moving averages, percentiles (moving medians in the case of the 50th percentile), and methods using other smoothing filters. Note that when calculating the amount of interference (received power) in the above equation (2), the propagation gain (the reciprocal of the propagation loss) is multiplied. Therefore, if some kind of average is used as the smoothing method, it is necessary to calculate the average of the reciprocal of the propagation loss.

[0092] Since radio waves have the property of being reflected and diffracted by surrounding features (buildings, mountains, etc.), propagation loss is easily affected by the surrounding environment (the shape of surrounding features). Therefore, the interference amount estimation means 143 calculates the propagation loss from the amount of interference received from wireless communication devices of other wireless communication systems 20, and accumulates the propagation loss for each group with similar interference attributes by dividing the groups by similar aggregation keys. When smoothing, if the shape of the surrounding features changes over time, the propagation loss value before and after the change will be different. Therefore, when smoothing is performed including both the values ​​before and after the change, the greater the change over time in the shape of the surrounding features, the greater the error immediately after the change. Therefore, the weight of the propagation loss accumulated at a predetermined time (hereinafter referred to as the "new weight") may be made larger than the weight of the propagation loss accumulated before the predetermined time (hereinafter referred to as the "old weight"), and the difference between the new weight and the old weight may be made larger as the amount of change over time in the shape of the feature around the wireless communication device 110 of the wireless communication system 10 itself or the amount of change over time in the shape of the feature around the wireless communication device 210 of the other wireless communication system 20 increases. An example of a method for grasping the amount of change in the shape of the surrounding feature is a method of acquiring 3D map data at predetermined time intervals and calculating the similarity (elevation correlation coefficient) between the latest 3D map data and the previously acquired 3D map data. As described above, when calculating the amount of interference (received power) in equation (2), the propagation gain (the reciprocal of the propagation loss) is multiplied, so the weight needs to be multiplied by the reciprocal of the propagation loss.

[0093] FIG. 6 shows data D8 as an example of a matrix for calculating an estimated value of propagation loss. In the matrix of data D8, tally numbers are assigned as row numbers, and time series numbers within a predetermined observation time are assigned as column numbers. In the matrix of data D8, an accumulated propagation loss value is set in each cell (for each combination of tally number and time series number). Also, FIG. 6 shows data D9 as a vector (vector indicating an estimated value of propagation loss) obtained by smoothing the matrix of data D8 for each tally number. In the vector of data D9, the propagation loss smoothed for each tally number from the matrix of data D8 is set.

[0094] Here, let us assume that data D1 of the interference attribute structure has the contents shown in Fig. 4. The interference attribute structure (data D1) shown in Fig. 4 is [receiving position = 8, transmitting position = 76, receiving antenna height = 15, transmitting antenna height = 21, interference level = 103].

[0095] Here, it is assumed that the smoothed data D4 of the terminal density around the receiving position and the smoothed data D5 of the terminal density around the transmitting position have the contents shown in Figures 3 and 4, respectively. Furthermore, it is assumed that the data D9 indicating the vector of the smoothed estimated value of the transmission loss has the contents shown in Figure 6.

[0096] Then, as shown in FIG. 4, the interference amount estimation means 143 first applies the value (8) of the receiving position in the data D1 of the interference attribute structure to the data D4 of the terminal density around the receiving position to obtain "92" as the terminal density around the receiving position, and then applies the value (76) of the transmitting position in the data D1 of the interference attribute structure to the data D5 of the terminal density around the transmitting position to obtain "23" as the terminal density around the transmitting position.

[0097] Next, the interference amount estimation means 143 generates data D6 of an aggregation key structure as shown in FIG. 4 based on the data D1 of the interference attribute structure and the acquired terminal density (92) around the receiving position and terminal density (23) around the transmitting position. The interference amount estimation means 143 sets the values ​​of the data D1 of the interference attribute structure for the receiving position, transmitting position, receiving antenna height, and transmitting antenna height of the aggregation key structure data D6. The interference amount estimation means 143 also sets the values ​​acquired from the data D4 and D5 as the terminal density around the receiving position and the terminal density around the transmitting position of the aggregation key structure data D6. As a result, the contents of the data D6 of the aggregation key structure acquired by the interference amount estimation means 143 are [receiving position=8, transmitting position=76, receiving antenna height=15, transmitting antenna height=21, terminal density around the receiving position=92, terminal density around the transmitting position=23], as shown in FIG. 4.

[0098] Next, the interference amount estimation means 143 applies the acquired data D6 of the tally key structure to the correspondence table D7 between the tally key value and the tally number shown in Fig. 5 to acquire the corresponding tally number. Here, since the contents of the data D6 of the tally key structure are those shown in Fig. 4, the corresponding tally number is 17619853, as shown in Fig. 5.

[0099] Next, the interference amount estimation means 143 applies the acquired tally number (17619853) to data D9 indicating a vector of the estimated value of the propagation loss, and acquires an estimated value of the propagation loss (112), as shown in Fig. 6. Then, as shown in Fig. 6, the interference amount estimation means 143 calculates R1 using the acquired estimated value of the propagation loss (112) as L in the above equation (2), and can acquire "78" as the estimated value of the interference amount.

[0100] When the wireless communication device 210 of the other wireless communication system 20 transmits intermittently using a packet communication system or the like, interference from the wireless communication device 110 of the own wireless communication system 10 to the wireless communication device 210 of the other wireless communication system 20 occurs only when the wireless communication device 210 of the other wireless communication system 20 is transmitting (another wireless communication device 210 of the other wireless communication system 20 is receiving). Therefore, the higher the transmission time rate (hereinafter referred to as "channel usage rate") of the wireless communication device 210 of the other wireless communication system 20, the higher the possibility of interference from the wireless communication device 110 of the own wireless communication system 10 to the wireless communication device 210 of the other wireless communication system 20. Therefore, it is desirable that the interference amount estimation means 143 reflects a weight based on the channel usage rate of the wireless communication device 210 of the other wireless communication system 20 around the transmission position (hereinafter referred to as "channel usage rate around the transmission position") in the estimated value of the interference amount.

[0101] The interference amount estimation means 143 may use the following two methods to reflect the weight based on the channel utilization rate around the transmission position in the estimated value of the interference amount.

[0102] [First Method] The interference amount estimation means 143 calculates the propagation loss from the amount of interference received from the wireless communication device of the other wireless communication system 20, and accumulates the propagation loss for each group with similar interference attributes by dividing the groups by similar aggregation keys, and when smoothing, the weight of the propagation loss accumulated during a time when the channel utilization rate around the transmission position is high is made larger than the weight of the propagation loss accumulated during a time when the channel utilization rate around the transmission position is low. As mentioned above, when calculating the amount of interference (received power) in equation (2), the propagation gain (the reciprocal of the propagation loss) is multiplied, so the weight needs to be multiplied by the reciprocal of the propagation loss.

[0103] [Second Method] The interference level estimation means 143 accumulates the path loss for each group with similar interference attributes, and when smoothing, does not use the weighting based on the channel utilization rate around the transmission position as described above. Instead, when estimating the interference level, the higher the channel utilization rate around the current transmission position, the greater the weight of the estimated value of path loss (the value after accumulating and smoothing the path loss for each group with similar interference attributes). Specifically, the above equation (2) is transformed into the following equation (3) and used (each term in the equation is in decibels). In equation (3), W is a weight based on the channel utilization rate. R1=P0+A0-F0-L+W+T1-F1...(3)

[0104] Two examples of methods for determining the weight W based on the channel utilization rate of the above-mentioned equation (3) are the following equations (4) and (5) (equations (5-1) and (5-2)) (each term in the equations is in decibels). Note that equation (5) is expressed as a set of equations (5-1) and (5-2). Equation (5) indicates that when the channel utilization rate around the transmission position is equal to or greater than a predetermined threshold, equation (5-1) is applied, and when the channel utilization rate around the transmission position is less than the predetermined threshold, equation (5-2) is applied. W = (predetermined constant K) + (channel utilization rate around the transmitting position) (4) W=0dB (antilogarithm 1) (5-1) W=-∞dB (antilogarithm 0) (5-2)

[0105] As mentioned above, when calculating the amount of interference (received power) in equation (2), the propagation gain (the reciprocal of the propagation loss) is multiplied, so the weight needs to be multiplied by the reciprocal of the propagation loss.

[0106] In the interference amount estimation means 143, the channel utilization rate around the transmitting position is retained (stored in a memory, etc.) as a column vector (hereinafter referred to as a "channel utilization rate vector around the transmitting position") having the same number of elements as the number of regions (regional meshes) obtained by dividing the range in which the wireless communication device 210 of the other wireless communication system 20 may be present into meshes of a predetermined size. The interference amount estimation means 143 acquires the channel utilization rate around the transmitting position in the regional mesh including the transmitting position from the transmitting position included in the stored interference state (for example, reads out the element of the row number corresponding to the regional mesh including the transmitting position in the channel utilization rate vector around the transmitting position described above). Furthermore, to calculate the channel utilization rate around the transmitting position, the interference amount estimation means 143 adds the time (hereinafter referred to as "transmission time") that the wireless communication device 210 of the other wireless communication system 20 transmitted radio waves within a predetermined time for each regional mesh including the transmitting position, and then divides the sum by the predetermined time. For example, the interference amount estimation means 143 adds the transmission time in the regional mesh including the transmission position every time it saves the interference state acquired from the wireless communication device 110 of its own wireless communication system 10 within a predetermined time. When the wireless communication device 210 of the other wireless communication system 20 transmits periodically, it is desirable that the predetermined time be an integer multiple of the transmission period so as to prevent an error in the channel utilization rate around the transmission position.

[0107] In the interference amount estimation means 143, the above-mentioned "transmission time" is either known (for example, if there is no significant difference between the transmission times, the average transmission time is stored as a representative value), or can be obtained by the interference attribute acquisition means 305 of the wireless communication device 110 of the own wireless communication system 10, which has received radio waves emitted by the wireless communication device 210 of the other wireless communication system 20, providing this information (if the wireless communication device of the own wireless communication system 10 is equipped with a demodulation circuit of the other wireless communication system 20, this information can be obtained from the MCS or data length included in the received data, or by measuring the reception time) to the interference management device 140 as one of the interference attributes.

[0108] The interference level estimation means 143 may perform smoothing by accumulating the channel utilization rates around the transmitting position within a predetermined time period. When a simple moving average is used as the smoothing method, for example, the row direction is the regional mesh including the transmitting position, and the column direction is a matrix stored in memory as a time series. In this case, the interference level estimation means 143 is assumed to be implemented as a ring buffer with the number of rows representing the number of regional meshes and the number of columns representing the number of accumulated channel utilization rates around the transmitting position within a predetermined time period (the time period for performing the moving average). Other applicable smoothing methods include weighted moving average, exponential moving average, percentile (moving median in the case of the 50th percentile), and other methods using smoothing filters.

[0109] (A-2) Operation of the First Embodiment Next, the operation of the communication system 1 according to the first embodiment (the communication processing method according to the embodiment) will be described.

[0110] FIG. 7 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10 itself.

[0111] First, it is assumed that the wireless communication device 110 of the wireless communication system 10 starts processing and receives radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20 via the wireless communication unit 101 (S101).

[0112] Then, the interference amount acquisition means 304 acquires the amount of interference from the wireless communication device 210 of the other wireless communication system 20 (S102), the interference attribute acquisition means 305 acquires the attribute of the amount of interference from the wireless communication device 210 of the other wireless communication system 20 (the interference attribute described above) (S103), and the interference status providing means 306 provides the amount of interference from the wireless communication device 210 of the other wireless communication system 20 and the attribute of the amount of interference from the wireless communication device 210 of the other wireless communication system 20 (the interference attribute described above) to the interference management device 140 (S104).

[0113] Then, the interference amount acquisition means 307 of the wireless communication device 110 acquires an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from the interference management device 140 (S105), the transmission signal acquisition means 301 acquires the transmission signal of the wireless communication system 10 itself (S106), and further the signal attribute acquisition means 303 acquires the attribute of the transmission signal of the wireless communication system 10 itself (S107).

[0114] Next, the interference information providing means 302 of the own wireless communication system 10 provides the acquired transmission signal, the attributes of the transmission signal of the own wireless communication system 10, and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 to the interference removal device 240 (S108), and proceeds again to the step (S101) of receiving radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20, and the subsequent steps are repeated.

[0115] FIG. 8 is a flowchart showing the operation of interference removal device 240.

[0116] It is assumed that the interference removal device 240 starts processing, and the interference information acquisition means 241 acquires the transmission signal of the own wireless communication system 10, the attributes of the transmission signal of the own wireless communication system 10, and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from the wireless communication device 110 of the own wireless communication system 10 (S201).

[0117] Then, it is assumed that the interference signal acquisition means 242 acquires the received signal of the other wireless communication system 20 (the signal that is the result of interference with the signal of the wireless communication system 10 itself) (S202).

[0118] When the processing of steps S201 and S202 is completed, the interference signal removal means 243 extracts the reception signal (desired signal) of the other wireless communication system 20 by estimating and removing the interference signal (interference signal from the own wireless communication system 10) included in the reception signal of the other wireless communication system 20, and returns the extracted reception signal (desired signal) to the wireless communication device 210 (the demodulation processing means 2012 of the wireless communication unit 201) (S203). Thereafter, the interference removal device 240 returns to the processing of step S201 described above and operates repeatedly.

[0119] Next, the interference management device 140 will be described.

[0120] First, the interference management device 140 starts processing, and the interference status acquisition means 141 acquires the amount of interference from the wireless communication device 210 of the other wireless communication system 20 and the attributes of the amount of interference from the wireless communication device 210 of the other wireless communication system 20 (the interference attributes described above) from the wireless communication device 110 of its own wireless communication system 10 (S301).

[0121] Next, the interference amount estimation means 143 estimates the amount of interference to the wireless communication device 210 of the other wireless communication system 20 (S302).

[0122] Next, the interference amount providing means 142 provides the estimated value of the interference amount to the wireless communication device 110 of its own wireless communication system 10 (S303). After that, the interference management device 140 returns to the above-mentioned step S301 and repeats the operation.

[0123] (A-3) Effects of the First Embodiment According to the first embodiment, the following effects can be achieved.

[0124] In the wireless communication device 110 of the first embodiment, the wireless communication device 110 of its own wireless communication system 10 acquires the attributes of the transmission signal of the wireless communication device 110 of its own wireless communication system 10 (an interference signal to the wireless communication device 210 of the other wireless communication system 20) and provides the attributes to the interference removal device 240 connected to the wireless communication device 210 of the other wireless communication system 20, thereby correctly estimating the interference signal from its own wireless communication system 10 (the interfering side), thereby reducing the residual interference signal and ensuring interference removal performance.

[0125] Furthermore, in this embodiment, an example of the attribute of the transmission signal of the wireless communication device 110 of the own wireless communication system 10 (interfering signal to the wireless communication device 210 of the other wireless communication system 20) is the interference start time of the transmission signal at the interfered side. Since there are many wireless communication devices 110 (interfering side) of the own wireless communication system 10 installed in roadside infrastructure and vehicles, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) of the own wireless communication system 10. Even when many interfering signals are added together and received at the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), it is possible to correctly determine the interference start time of the transmission signal at the interfered side and remove the interfering signal from the own wireless communication system 10 (interfering side). Therefore, by correctly estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interfering signal and ensure interference removal performance.

[0126] Furthermore, in this embodiment, an example is given in which the attribute of the transmission signal of the wireless communication device 110 of the own wireless communication system 10 (an interference signal to the wireless communication device 210 of the other wireless communication system 20) is the carrier frequency difference of the transmission signal of the wireless communication device 110 of the own wireless communication system 10. Because the vehicle 120 of the own wireless communication system 10 and the vehicle 220 of the other wireless communication system 20 move, the wireless communication device 110 (interfering side) of the own wireless communication system 10 that receives interference from the wireless communication device 210 (interfered side) of the other wireless communication system 20 is unspecified. Furthermore, if it is impossible to adjust the wireless communication device so that the frequency difference is negligible by selecting a crystal device in advance, and further, there are many wireless communication devices 110 (interfering side) of the own wireless communication system 10 installed in roadside infrastructure and vehicles, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) of the own wireless communication system 10. As a result, even when a large number of interfering signals are added together and received on the interfered side (when multiple signals with different phases are added together and the amplitude becomes 0), the wireless communication device 110 (interfering side) of its own wireless communication system 10 is provided with a demodulation circuit of the other wireless communication system 20 for each interfering signal, and the demodulation circuit detects the phase difference between received symbols, thereby making it possible to estimate and correct the carrier frequency difference. As a result, by correctly estimating the interfering signal from its own wireless communication system 10 (interfering side), it is possible to reduce the residual interfering signal and ensure interference removal performance.

[0127] Furthermore, the wireless communication device 110 of its own wireless communication system 10 obtains an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 and provides it to the interference removal device 240 connected to the wireless communication device 210 of the other wireless communication system 20, thereby correctly estimating the interference signal from its own wireless communication system 10 (interfering side), thereby reducing the residual interference signal and ensuring interference removal performance.

[0128] That is, since there are many wireless communication devices 110 (interfering side) of the own wireless communication system 10 mounted on roadside infrastructure and vehicles, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) of the own wireless communication system 10, and even when many interfering signals are added together and received at the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), it is possible to remove the interfering signal from the own wireless communication system 10 (interfering side) that has been distorted by radio wave propagation. As a result, by correctly estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interfering signal and ensure interference removal performance.

[0129] Furthermore, the interference management device 140 can smooth a large number of radio wave propagation characteristics by acquiring the amount of interference from the radio communication devices 210 of the other radio communication systems 20 from a large number of the radio communication devices 110 of its own radio communication system 10, thereby improving the accuracy of estimating the radio wave propagation characteristics and enabling accurate estimation of the amount of interference to the radio communication devices 210 of the other radio communication systems 20. This enables the radio communication devices 210 of the other radio communication systems 20 to remove the interference signal from its own radio communication system 10 (interfering side) that has been distorted by radio wave propagation, and by more accurately estimating the interference signal from its own radio communication system 10 (interfering side), it is possible to reduce the residual interference signal and ensure interference removal performance.

[0130] Furthermore, by smoothing the radio wave propagation characteristics for each of the transmitting and receiving antenna heights and the terminal density around the transmitting and receiving vehicles in addition to the transmitting and receiving positions, the estimation accuracy of the radio wave propagation characteristics is further improved, and it is possible to more accurately estimate the amount of interference to the radio communication device 210 of the other radio communication system 20. As a result, the radio communication device 210 of the other radio communication system 20 can remove the interference signal from its own radio communication system 10 (interfering side) that has been distorted by radio wave propagation, and by more accurately estimating the interference signal from its own radio communication system 10 (interfering side), it is possible to further reduce the residual interference signal, and it is possible to more reliably ensure interference removal performance.

[0131] (B) Second embodiment A second embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described below in detail with reference to the drawings.

[0132] (B-1) Configuration and operation of the second embodiment Fig. 10 is a block diagram showing the overall configuration of a communication system 1 according to the second embodiment. In Fig. 10, the same or corresponding reference numerals are used to designate the same or corresponding parts as in Fig. 1 described above.

[0133] The following describes the differences between the communication system 1 of the second embodiment and the first embodiment.

[0134] The communication system 1 of the second embodiment differs from the first embodiment in that a wireless communication device 500 is additionally disposed as a third wireless communication device capable of communicating in the same communication system as each wireless communication device 110 of the wireless communication system 10 in or near a roadside infrastructure 230 (wireless communication device 210-0 and interference removal device 240) constituting the other wireless communication system 20. In the second embodiment, the configuration of the transmission path between the interference removal device 240 and the wireless communication device 500 is not limited, and communication is possible via various wired or wireless transmission paths. For example, the interference removal device 240 and the wireless communication device 500 may be configured to communicate via a wired connection such as a USB interface (USB cable) or a LAN cable. Note that the wireless communication device 500 may be configured to support the same wireless communication system as each wireless communication device 210 of the other wireless communication system 20 and to be capable of mutual communication.

[0135] As described above, the wireless communication device 500 can communicate with both its own wireless communication system 10 (each wireless communication device 110) and another wireless communication system 20 (such as the interference management device 140), and therefore can be said to belong to both systems. However, for the sake of simplicity, the following description will be given of the wireless communication device 500 as an element constituting the other wireless communication system 20.

[0136] In the communication system 1 of the second embodiment, the wireless communication device 500 provides information (transmission signal, signal attribute, amount of interference) related to interference in its own wireless communication system 10 to the interference removal device 240. In this case, it is desirable that the wireless communication device 500 is provided with a directional antenna using means such as beamforming as the antenna 1011, thereby receiving only radio wave signals (interference signals) from a specific wireless communication device 110 in its own wireless communication system 10 and suppressing radio wave interference from other wireless communication devices 110.

[0137] In the first embodiment, a communication path 400 was set between the roadside infrastructure 130 (wireless communication device 110-0) of the own wireless communication system 10 and the interference removal device 240 of the other wireless communication system 20, but in the second embodiment, the wireless communication device 500 is excluded because it can communicate with the interference removal device 240.

[0138] Fig. 11 is a block diagram showing the configuration of each device constituting the communication system 1 according to the second embodiment. In Fig. 11, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 2 described above.

[0139] 11, the components of each wireless communication device 110 (110-0, 110-1, 110-2, ...) are the same as those in the first embodiment, but the presence of wireless communication device 500 means that the paths for obtaining and providing each piece of information are different in the second embodiment. Note that in the second embodiment, the radio wave interference control unit 300 may be excluded from each wireless communication device 110 (110-0, 110-1, 110-2, ...) other than wireless communication device 500.

[0140] The following describes the differences in the configuration of wireless communication device 500 from the first embodiment.

[0141] 11, the wireless communication device 500 includes a wireless communication unit 101 and a radio wave interference control unit 300, similar to the wireless communication device 110 of the first embodiment. In the second embodiment, each component of the radio wave interference control unit 300 included in the wireless communication device 500 differs from that of the first embodiment. Below, differences from the first embodiment will be described for each element of the radio wave interference control unit 300 included in the wireless communication device 500.

[0142] The second embodiment differs from the first embodiment in that the transmission signal acquisition means 301 of the wireless communication device 500 acquires the transmission signal by receiving and demodulating (demodulating using the demodulation processing means 1012 of the wireless communication unit 101) the wireless signal transmitted by each wireless communication device 110 (110-0, 110-1, 110-2, ...) of its own wireless communication system 10.

[0143] The second embodiment is also different from the first embodiment in that the signal attribute acquisition means 303 of the wireless communication device 500 can directly acquire the time at which reception of a wireless signal transmitted by each wireless communication device 110 (110-0, 110-1, 110-2, ...) of its own wireless communication system 10 started. The signal attribute acquisition means 303 of the wireless communication device 500 is also different from the first embodiment in that it can estimate a carrier frequency difference of a transmission signal in each wireless communication device 110 (110-0, 110-1, 110-2, ...) (interfering side) of its own wireless communication system 10 by receiving and demodulating (using the demodulation processing means 1012 of the wireless communication unit 101) the wireless signal transmitted by each wireless communication device 110 (110-0, 110-1, 110-2, ...).

[0144] Furthermore, the second embodiment differs from the first embodiment in that the interference information providing means 302 of the wireless communication device 500 provides the interference information (transmission signal, signal attributes, amount of interference) of its own system that it has acquired to the directly connected interference removal device 240 (interference information acquiring means 241).

[0145] Furthermore, in the second embodiment, the interference amount acquisition means 304 of the wireless communication device 500 receives wireless signals transmitted from each wireless communication device 110 (110-0, 110-1, 110-2, ...) of its own wireless communication system 10 (holds the wireless signals acquired by the demodulation processing means 1012 of the wireless communication unit 101 of the wireless communication device 500), thereby acquiring the interference amount (the amount of interference from the wireless communication device 110 of its own wireless communication system 10 to the wireless communication device 500 of the other wireless communication system 20, which corresponds to the amount of interference from the own wireless communication system 10 to the other wireless communication system 20), and supplies it to the interference status providing means 306.

[0146] Furthermore, in the second embodiment, the interference attribute acquisition means 305 of the wireless communication device 500 acquires an attribute of the amount of interference received from the own wireless communication system 10 to the other wireless communication system 20. Therefore, in the description of the example of the interference attribute in the first embodiment, the side that causes interference in the amount of interference received is the other wireless communication system 20, and the side that is interfered with in the amount of interference received is the own wireless communication system 10, whereas in the description of the example of the interference attribute in the second embodiment, it is necessary to read the side that causes interference in the amount of interference received as the own wireless communication system 10, and the side that is interfered with in the amount of interference received as the other wireless communication system 20 (that is, if the own wireless communication system 10 and the other wireless communication system 20 are interchanged in the description of the example of the interference attribute in the first embodiment, the description becomes an example of the interference attribute in the second embodiment). Note that, in the second embodiment, the wireless communication device 500 is physically located on the other wireless communication system 20 side, and therefore, information on the side that is interfered with in the amount of interference received, among the information of the interference attribute, can be acquired from the roadside infrastructure 230 on the other wireless communication system 20 side, each vehicle 220, etc.

[0147] Furthermore, in the second embodiment, the interference amount estimation means 143 of the interference management device 140 acquires an estimate of the amount of interference (the amount of interference from the wireless communication device 110 of its own wireless communication system 10 to the wireless communication device 210 of the other wireless communication system 20) based on the amount of interference previously acquired from the wireless communication device 500 of the other wireless communication system 20 (the amount of interference from the wireless communication device 110 of its own wireless communication system 10 to the wireless communication device 500 of the other wireless communication system 20) and the interference attribute, and provides this to the interference amount providing means 142. In addition, in the explanation of the interference amount estimation means 143, R0 needs to be read as the received power of the radio waves transmitted by the wireless communication device 110 of its own wireless communication system 10 at the wireless communication device 500 of the other wireless communication system 20, P1, A1, F1 respectively as the transmission power, antenna gain, loss due to the transmitting power feeder line, etc. of the wireless communication device 110 of its own wireless communication system 10, and T0, J0 respectively as the receiving antenna gain, loss due to the receiving power feeder line, etc. of the wireless communication device 500 of the other wireless communication system 20. Furthermore, L in equations (1) and (2) will be the same if the receiving antenna of wireless communication device 500 and the receiving antenna of wireless communication device 210 can be considered to be at approximately the same position and height.

[0148] (B-2) Operation of the Second Embodiment Next, the differences between the operation of the communication system 1 according to the second embodiment (the communication processing method according to the embodiment) and the first embodiment will be described.

[0149] The operation of the communication system 1 of the second embodiment can also be explained using the above-mentioned FIGS.

[0150] In the second embodiment, the processing of the flowchart in Fig. 7 differs from the first embodiment in that it is the operation of the wireless communication device 500 constituting the other wireless communication system 20. The processing by the wireless communication device 500 to acquire each piece of information (processing of the transmission signal acquisition means 301, signal attribute acquisition means 303, interference amount acquisition means 304, interference attribute acquisition means 305, and interference amount acquisition means 307) is as described above. Also, in the second embodiment, the processing of the flowchart in Fig. 8 differs from the first embodiment in that it is processing between the wireless communication device 500 and the interference removal device 240. Furthermore, in the second embodiment, the processing of the flowchart in Fig. 9 differs from the first embodiment in that it is processing between the wireless communication device 500 and the interference management device 140.

[0151] (B-3) Effects of the Second Embodiment According to the second embodiment, in addition to the effects of the first embodiment, the following effects can be achieved.

[0152] In the second embodiment, a wireless communication device 500 capable of communicating with the own wireless communication system 10 is arranged on the side of the other wireless communication system 20. As a result, in the second embodiment, by simply arranging the radio wave interference control unit 300 only in the wireless communication device 500 in the own wireless communication system 10, it is possible to perform interference removal processing similar to the first embodiment without arranging the radio wave interference control unit 300 in the roadside infrastructure 130 or the wireless communication devices 110 (110-0, 110-1, 110-2, ...) of each vehicle 120.

[0153] (C) Third embodiment Hereinafter, a third embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described in detail with reference to the drawings.

[0154] (C-1) Configuration of the third embodiment The overall configuration of the communication system 1 of the third embodiment can also be shown using the above-mentioned Fig. 1. The following describes the differences between the third embodiment and the first embodiment.

[0155] Fig. 12 is a block diagram showing the configuration of each device constituting the communication system 1 according to the second embodiment. In Fig. 12, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 2 described above.

[0156] The third embodiment differs from the first embodiment in that the signal attribute acquisition means 303 is excluded from each wireless communication device 110 in the wireless communication system 10 itself.

[0157] In the third embodiment, the interference signal removal means 243 of the interference removal device 240 cannot acquire the attributes of the transmission signal of its own wireless communication system 10, so it estimates and removes the interference signal from its own wireless communication system 10 based on the transmission signal of its own wireless communication system 10 and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20.

[0158] Furthermore, in the third embodiment, the interference signal removing means 243 does not perform the first correction process. In addition, instead of the attribute of the transmission signal of its own wireless communication system 10 (for example, the interference start time of the transmission signal on the interfered side), it is necessary for the interference signal removing means 243 to estimate the interference start time of the transmission signal on the interfered side by itself, and it is conceivable to use, for example, the time when the interference information acquiring means 241 acquired the transmission signal of its own wireless communication system 10.

[0159] Similarly, in the second embodiment, the wireless communication device 500 can have the same configuration as the wireless communication device 110 of the third embodiment shown in FIG.

[0160] (C-2) Operation of the Third Embodiment Next, the differences between the operation of the communication system 1 according to the second embodiment (the communication processing method according to the embodiment) and the first embodiment will be described.

[0161] Fig. 13 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10. In Fig. 13, the same or corresponding step numbers as those in Fig. 7 above are assigned to steps that are the same as or correspond to those in Fig. 7 above.

[0162] 13 differs from the first embodiment (FIG. 7) in that step S107 is omitted and step S108 is replaced with step S108B.

[0163] In step S108B, the interference information providing means 302 of the own wireless communication system 10 provides the obtained transmission signal and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 to the interference removal device 240.

[0164] Fig. 14 is a flowchart showing the operation of the interference management device 140 constituting the other wireless communication system 20. In Fig. 14, the same or corresponding step numbers as those in Fig. 8 above are assigned to steps that are the same as or correspond to those in Fig. 8 above.

[0165] 14 differs from the first embodiment (FIG. 8) in that steps S201 and S203 are replaced with steps S201B and S203B, respectively.

[0166] First, the interference removal device 240 starts processing, and the interference information acquisition means 241 acquires an estimated value of the amount of interference to the transmission signal of the own wireless communication system 10 and the wireless communication device 210 of the other wireless communication system 20 from the wireless communication device 110 of the own wireless communication system 10 (S201B).

[0167] Then, it is assumed that the interference signal acquisition means 242 acquires the received signal of the other wireless communication system 20 (the signal that is the result of interference with the signal of the wireless communication system 10 itself) (S202).

[0168] When the processing of steps S201B and S202 is completed, the interference signal removal means 243 extracts the reception signal (desired signal) of the other wireless communication system 20 by estimating and removing the interference signal (interference signal from its own wireless communication system 10) included in the reception signal of the other wireless communication system 20, and returns the extracted reception signal (desired signal) to the wireless communication device 210 (the demodulation processing means 2012 of the wireless communication unit 201) (S203B). At this time, the interference signal removal means 243 cannot acquire the attribute of the transmission signal of its own wireless communication system 10, so estimates and removes the interference signal from its own wireless communication system 10 from the transmission signal of its own wireless communication system 10 and an estimated value of the amount of interference of the other wireless communication system 20 to the wireless communication device 210. Thereafter, the interference removal device 240 returns to the processing of the above-mentioned step S201B and operates repeatedly.

[0169] In the third embodiment, the operation of the interference management device 140 is the same as in the first embodiment (the flowchart in FIG. 9 above), and therefore a detailed description thereof will be omitted.

[0170] Next, the operation of the wireless communication device 500 in the second embodiment will be described when a configuration similar to that of the wireless communication device 110 in the third embodiment shown in Fig. 12 is applied to the wireless communication device 500. In this case, the processing of the flowchart in Fig. 13 is the operation of the wireless communication device 500 constituting the other wireless communication system 20. In addition, in this case, the processing of the flowchart in Fig. 14 is the processing between the wireless communication device 500 and the interference removal device 240.

[0171] (C-3) Effects of the Third Embodiment According to the third embodiment, the following effects can be achieved, similar to the first embodiment.

[0172] In the third embodiment, the wireless communication device 110 of the own wireless communication system 10 acquires an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 and provides it to the interference removal device 240 connected to the wireless communication device 210 of the other wireless communication system 20, thereby correctly estimating the interference signal from the own wireless communication system 10 (interfering side), thereby reducing the residual interference signal and ensuring interference removal performance.

[0173] That is, since there are many wireless communication devices 110 (interfering side) in the own wireless communication system 10, the wireless communication device 210 (interfered side) in the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) in the own wireless communication system 10, and even when many interfering signals are added together and received at the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), it is possible to remove the interfering signal from the own wireless communication system 10 (interfering side) that has been distorted by radio wave propagation. As a result, in the third embodiment, by correctly estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interfering signal and ensure interference removal performance.

[0174] Moreover, in the third embodiment, the interference management device 140 acquires the amount of interference from the wireless communication devices 210 of the other wireless communication systems 20 from a large number of wireless communication devices 110 of the own wireless communication system 10. As a result, in the third embodiment, it is possible to smooth a large number of radio wave propagation characteristics, thereby improving the estimation accuracy of the radio wave propagation characteristics and accurately estimating the amount of interference to the wireless communication devices 210 of the other wireless communication systems 20. This makes it possible to remove the interfering signal from the own wireless communication system 10 (interfering side) that has been distorted by radio wave propagation, and by more accurately estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to further reduce the residual amount of the interfering signal and ensure interference removal performance.

[0175] Furthermore, in the third embodiment, by smoothing the radio wave propagation characteristics for each of the transmitting and receiving antenna heights and the terminal density around the transmitting and receiving vehicles in addition to the transmitting and receiving positions, the estimation accuracy of the radio wave propagation characteristics is further improved, and it is possible to more accurately estimate the amount of interference to the radio communication device 210 of the other radio communication system 20. As a result, in the third embodiment, it is possible to remove the interference signal from the own radio communication system 10 (interfering side) that has been distorted by radio wave propagation, and by more accurately estimating the interference signal from the own radio communication system 10 (interfering side), it is possible to further reduce the residual interference signal, and it is possible to more reliably ensure interference removal performance.

[0176] In the second embodiment, the same effects as those described above can be achieved even when the same configuration as that of the wireless communication device 110 of the third embodiment shown in FIG. 12 is applied to the wireless communication device 500.

[0177] (D) Fourth embodiment A fourth embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described below in detail with reference to the drawings.

[0178] (D-1) Configuration of the fourth embodiment The overall configuration of the communication system 1 of the fourth embodiment can also be shown using the above-mentioned Fig. 1. The following describes the differences between the fourth embodiment and the third embodiment.

[0179] Fig. 15 is a block diagram showing the configuration of each device constituting the communication system 1 according to the fourth embodiment. In Fig. 15, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 12 described above.

[0180] The fourth embodiment differs from the third embodiment in that the interference amount acquisition means 304 is removed from each wireless communication device 110 in the wireless communication system 10 itself.

[0181] In the fourth embodiment, the interference management device 140 cannot acquire the amount of interference received, and therefore does not store the estimated value of the propagation loss (does not update the time series for calculating the estimated value of the propagation loss in Figures 3 to 6), which is different from the third embodiment.

[0182] In the fourth embodiment, the interference management device 140 may acquire the amount of interference from a vehicle (radio wave measurement vehicle) or the like equipped with a wireless communication device capable of acquiring the amount of interference (capable of receiving radio waves transmitted by a wireless communication device 210 of another wireless communication system 20) instead of each wireless communication device 110 of its own wireless communication system 10.

[0183] Similarly, in the second embodiment, the wireless communication device 500 can have the same configuration as the wireless communication device 110 of the fourth embodiment shown in FIG.

[0184] (D-2) Operation of the Fourth Embodiment Next, the operation of the communication system 1 according to the fourth embodiment (the communication processing method according to the embodiment) will be described in terms of differences from the third embodiment.

[0185] Fig. 16 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10 according to the fourth embodiment. In Fig. 16, the same or corresponding step numbers as those in Fig. 13 above are assigned to steps that are the same as or correspond to those in Fig. 13 above.

[0186] FIG. 16 differs from the third embodiment in that steps S101 and S102 are excluded from the first embodiment (FIG. 13) and step S104 is replaced with step S104C.

[0187] In step S104C, the interference status providing means 306 of the wireless communication device 110 provides the interference management device 140 with only the attribute of the amount of interference received supplied from the interference attribute obtaining means 305 (the interference attribute described above).

[0188] In the fourth embodiment, the operation of the interference removal device 240 is the same as in the third embodiment (the flowchart in FIG. 14 above), and therefore a detailed description thereof will be omitted.

[0189] Fig. 17 is a flowchart showing the operation of the interference management device 140 constituting the other wireless communication system 20 in the fourth embodiment. In Fig. 17, the same or corresponding step numbers are assigned to steps that are the same as or correspond to those in Fig. 9 described above.

[0190] FIG. 17 differs from the third embodiment (first embodiment) in that steps S301 and S302 in the third embodiment (FIG. 9 of the first embodiment) are replaced with steps S301C and S302C, respectively.

[0191] First, the interference management device 140 starts processing, and the interference status acquisition means 141 acquires the attribute of the amount of interference (the interference attribute described above) from the wireless communication device 210 of the other wireless communication system 20 from the wireless communication device 110 of its own wireless communication system 10 (S301C).

[0192] Next, the interference amount estimation means 143 estimates the amount of interference to the wireless communication device 210 of the other wireless communication system 20 based on the attribute of the amount of interference received (S302C). As described above, the interference management device 140 in the fourth embodiment cannot acquire the amount of interference received, and therefore does not store the estimated value of the propagation loss (does not update the time series for calculating the estimated value of the propagation loss in FIGS. 3 to 6), which is different from the third embodiment.

[0193] Next, the interference amount providing means 142 provides the estimated value of the interference amount to the wireless communication device 110 of its own wireless communication system 10 (S303). After that, the interference management device 140 returns to the above-mentioned step S301 and repeats the operation.

[0194] Next, in the second embodiment, the operation of the wireless communication device 500 when applying a configuration similar to that of the wireless communication device 110 of the fourth embodiment shown in Fig. 15 will be described. In this case, the processing of the flowchart in Fig. 16 is the operation of the wireless communication device 500 constituting the other wireless communication system 20. In addition, in this case, the processing of the flowchart in Fig. 17 is the processing between the wireless communication device 500 and the interference management device 140.

[0195] (D-3) Effects of the Fourth Embodiment According to the fourth embodiment, in addition to the effects of the third embodiment, the following effects can be achieved.

[0196] In the fourth embodiment, the interference management device 140 acquires the amount of interference from a vehicle (radio wave measurement vehicle) or the like equipped with a wireless communication device capable of acquiring the amount of interference (capable of receiving radio waves transmitted by the wireless communication device 210 of the other wireless communication system 20) instead of each wireless communication device 110 of the own wireless communication system 10. This makes it possible to perform interference removal processing in the same way as in the third embodiment, even if the interference amount acquisition means 304 is not provided in each wireless communication device 110 of the own wireless communication system 10.

[0197] In the second embodiment, the same effects as those described above can be achieved even when the same configuration as that of the wireless communication device 110 of the fourth embodiment shown in FIG. 15 is applied to the wireless communication device 500.

[0198] (E) Fifth embodiment Hereinafter, a fifth embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described in detail with reference to the drawings.

[0199] (E-1) Configuration of the fifth embodiment Fig. 18 is a diagram showing the overall configuration of a communication system 1 according to the fifth embodiment. In Fig. 18, the same or corresponding parts as those in Fig. 1 (first embodiment) above are denoted by the same or corresponding reference numerals.

[0200] Fig. 19 is a block diagram showing the configuration of each device constituting a communication system 1 according to the fifth embodiment. In Fig. 19, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 2 described above.

[0201] The following describes the differences between the fifth embodiment and the first embodiment.

[0202] The communication system 1 of the fifth embodiment differs from the first embodiment in that the interference management device 140 is excluded, and the interference amount estimation means 143 constituting the interference management device 140 in the first embodiment is arranged on the wireless communication device 110 (radio interference control unit 300) side. Also, the wireless communication device 110 of the fifth embodiment differs from the first embodiment in that the interference attribute acquisition means 305, the interference status providing means 306, and the interference amount acquisition means 307 are excluded.

[0203] In the fifth embodiment, the interference amount acquisition means 304 supplies the acquired amount of interference to the interference amount estimation means 143. Also, in the fifth embodiment, the interference amount estimation means 143 acquires an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 based on the amount of interference acquired from the interference amount acquisition means 304, and provides the estimate to the interference information providing means 302.

[0204] In the fifth embodiment, since the interference management device 140 is not provided, the interference amount estimation means 143 needs to autonomously acquire an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20. For example, as an example of a method for acquiring an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20, the interference amount estimation means 143 may calculate a propagation loss from the amount of interference acquired from the interference amount acquisition means 304, and calculate an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from the latest value of the propagation loss. Also, for example, the interference amount estimation means 143 may calculate a propagation loss from the amount of interference acquired from the interference amount acquisition means 304, accumulate the propagation loss within a predetermined time, and calculate an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from a smoothed value. Furthermore, for example, the interference amount estimation means 143 may have the same function as the interference attribute acquisition means 305 in the first embodiment, accumulate propagation losses for each group with similar interference attributes, and calculate an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 from the smoothed value.

[0205] Similarly, in the second embodiment, the interference management device 140 can be removed, and the wireless communication device 500 can have the same configuration as the wireless communication device 110 of the fifth embodiment shown in FIG.

[0206] (E-2) Operation of the Fifth Embodiment Next, the differences between the operation of the communication system 1 according to the fifth embodiment (the communication processing method according to the embodiment) and the first embodiment will be described.

[0207] Fig. 20 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10 according to the fifth embodiment. In Fig. 20, the same or corresponding step numbers as those in Fig. 7 above are assigned to steps that are the same as or correspond to those in Fig. 7 above.

[0208] 20 differs from the first embodiment (FIG. 7) in that steps S103 and S104 are excluded and step S105 is replaced with step S105D.

[0209] In step S105D, the interference amount estimation means 143 autonomously acquires an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20, and provides the acquired estimate of the amount of interference to the interference information providing means 302.

[0210] In the fifth embodiment, the operation of the interference removal device 240 is the same as in the first embodiment (see FIG. 8 above), and therefore a detailed description thereof will be omitted.

[0211] Next, the operation of the wireless communication device 500 in the second embodiment will be described when a configuration similar to that of the wireless communication device 110 in the fifth embodiment shown in Fig. 19 is applied to the wireless communication device 500. In this case, the processing of the flowchart in Fig. 20 is the operation of the wireless communication device 500 constituting the other wireless communication system 20. In addition, in this case, the processing of the flowchart in Fig. 8 is the processing between the wireless communication device 500 and the interference removal device 240.

[0212] (E-3) Effects of the Fifth Embodiment According to the fifth embodiment, in addition to the effects of the first embodiment, the following effects can be achieved.

[0213] In the fifth embodiment, the interference amount estimation means 143 is arranged on the wireless communication device 110 side, thereby eliminating the interference management device 140. As a result, in the fifth embodiment, it is not necessary to arrange the interference management device 140, and therefore it is possible to build and operate the system at lower cost.

[0214] In the second embodiment, the same effect as described above can be achieved even when the wireless communication device 500 has a configuration similar to that of the wireless communication device 110 of the fifth embodiment shown in FIG. 19 and the interference management device 140 is excluded.

[0215] (F) Sixth embodiment Hereinafter, a sixth embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described in detail with reference to the drawings.

[0216] (F-1) Configuration of the Sixth Embodiment The overall configuration of the communication system 1 of the sixth embodiment can also be shown using the above-mentioned Fig. 18. The following describes the sixth embodiment in terms of differences from the fifth embodiment.

[0217] Fig. 21 is a block diagram showing the configuration of each device constituting the communication system 1 according to the sixth embodiment. In Fig. 21, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 19 described above.

[0218] The sixth embodiment differs from the first embodiment in that the signal attribute acquisition means 303 is excluded from each wireless communication device 110 in the wireless communication system 10 itself.

[0219] In the sixth embodiment, the interference signal removal means 243 of the interference removal device 240 cannot acquire the attributes of the transmission signal of its own wireless communication system 10, and therefore estimates and removes the interference signal from its own wireless communication system 10 based on the transmission signal of its own wireless communication system 10 and an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20.

[0220] Furthermore, in the third embodiment, the interference signal removing means 243 does not perform the first correction process. In addition, instead of the attribute of the transmission signal of its own wireless communication system 10 (for example, the interference start time of the transmission signal on the interfered side), it is necessary for the interference signal removing means 243 to estimate the interference start time of the transmission signal on the interfered side by itself, and it is conceivable to use, for example, the time when the interference information acquiring means 241 acquired the transmission signal of its own wireless communication system 10.

[0221] Similarly, in the second embodiment, the wireless communication device 500 can have the same configuration as the wireless communication device 110 of the sixth embodiment shown in FIG.

[0222] (F-2) Operation of the Sixth Embodiment Next, the differences between the operation of the communication system 1 according to the sixth embodiment (the communication processing method according to the embodiment) and the fifth embodiment will be described.

[0223] Fig. 22 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10. In Fig. 22, the same or corresponding step numbers as those in Fig. 20 above are assigned to steps that are the same as or correspond to those in Fig. 20 above.

[0224] FIG. 22 differs from the first embodiment in that step S107 is omitted and step S108 is replaced with step S108E, as compared with the fifth embodiment (FIG. 20).

[0225] In step S108E, the interference information providing means 302 of the own wireless communication system 10 provides the obtained transmission signal and an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 to the interference removal device 240.

[0226] Fig. 23 is a flowchart showing the operation of the interference management device 140 constituting the other wireless communication system 20. In Fig. 23, the same or corresponding step numbers are assigned to steps that are the same as or correspond to those in the fifth embodiment (Fig. 8 relating to the first embodiment).

[0227] FIG. 23 differs from the first embodiment in that steps S201 and S203 in the fifth embodiment (FIG. 8 relating to the first embodiment) are replaced with steps S201E and S203E, respectively.

[0228] It is assumed that the interference removal device 240 starts processing, and the interference information acquisition means 241 acquires an estimated value of the amount of interference to the transmission signal of the own wireless communication system 10 and the wireless communication device 210 of the other wireless communication system 20 from the wireless communication device 110 of the own wireless communication system 10 (S201E).

[0229] Then, it is assumed that the interference signal acquisition means 242 acquires the received signal of the other wireless communication system 20 (the signal that is the result of interference with the signal of the wireless communication system 10 itself) (S202).

[0230] When the processes of steps S201E and S202 are completed, the interference signal removal means 243 extracts the reception signal (desired signal) of the other wireless communication system 20 by estimating and removing the interference signal (interference signal from its own wireless communication system 10) included in the reception signal of the other wireless communication system 20, and returns the extracted reception signal (desired signal) to the wireless communication device 210 (the demodulation processing means 2012 of the wireless communication unit 201) (S203E). At this time, the interference signal removal means 243 cannot acquire the attribute of the transmission signal of its own wireless communication system 10, so estimates and removes the interference signal from its own wireless communication system 10 from the transmission signal of its own wireless communication system 10 and an estimated value of the amount of interference from the other wireless communication system 20 to the wireless communication device 210. Thereafter, the interference removal device 240 returns to the process of step S201E described above and operates repeatedly.

[0231] Next, the operation of the wireless communication device 500 in the second embodiment will be described when a configuration similar to that of the wireless communication device 110 in the sixth embodiment shown in Fig. 21 is applied to the wireless communication device 500. In this case, the processing of the flowchart in Fig. 22 is the operation of the wireless communication device 500 constituting the other wireless communication system 20. In addition, in this case, the processing of the flowchart in Fig. 23 is the processing between the wireless communication device 500 and the interference removal device 240.

[0232] (F-3) Effects of the Sixth Embodiment According to the sixth embodiment, the following effects can be achieved, similar to the third and fifth embodiments.

[0233] In the communication system 1 of the sixth embodiment, the wireless communication device 110 of its own wireless communication system 10 acquires an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20, and provides it to the interference removal device 240 connected to the wireless communication device 210 of the other wireless communication system 20. This makes it possible to correctly estimate the interference signal from its own wireless communication system 10 (interfering side), thereby reducing the residual interference signal and ensuring interference removal performance.

[0234] That is, since there are many wireless communication devices 110 (interfering side) of the own wireless communication system 10 mounted on the roadside infrastructure 130 and the vehicle 120, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) of the own wireless communication system 10, and even when many interfering signals are added together and received at the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), it is possible to remove the interfering signal from the own wireless communication system 10 (interfering side) that has been distorted by radio wave propagation. As a result, in the sixth embodiment, by correctly estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interfering signal and ensure interference removal performance.

[0235] In the sixth embodiment, the interference amount estimation means 143 is arranged on the wireless communication device 110 side, thereby eliminating the interference management device 140. As a result, in the sixth embodiment, it is not necessary to arrange the interference management device 140, and therefore it is possible to build and operate the system at lower cost.

[0236] In the second embodiment, the same effect as described above can be achieved even when the wireless communication device 500 has a configuration similar to that of the wireless communication device 110 of the sixth embodiment shown in FIG. 21 and the interference management device 140 is excluded.

[0237] (G) Seventh embodiment Hereinafter, a seventh embodiment of a communication system, a communication method, an interference cancellation device, and an interference cancellation program according to the present invention will be described in detail with reference to the drawings.

[0238] (G-1) Configuration of the Seventh Embodiment The overall configuration of the communication system 1 according to the seventh embodiment can also be shown using the above-mentioned Fig. 18. The following describes the differences between the seventh embodiment and the fifth embodiment.

[0239] Fig. 24 is a block diagram showing the configuration of each device constituting the communication system 1 according to the seventh embodiment. In Fig. 24, the same or corresponding reference numerals are used to denote the same or corresponding parts as in Fig. 19 described above.

[0240] The communication system 1 of the seventh embodiment differs from the fifth embodiment in that the wireless communication device 110 of its own wireless communication system 10 does not include the interference level acquisition means 304 and the interference level estimation means 143.

[0241] In the seventh embodiment, the interference signal removal means 243 of the interference removal device 240 cannot obtain an estimated value of the amount of interference to the wireless communication device 210 of the other wireless communication system 20, and therefore differs from the fifth embodiment in that it estimates and removes the interference signal from the own wireless communication system 10 based on the transmission signal of the own wireless communication system 10 and the attributes of the transmission signal of the own wireless communication system 10.

[0242] Furthermore, in the seventh embodiment, the interference signal removal means 243 does not perform the second correction process. In addition, when a plurality of self-system transmission signals (interference signals to the wireless communication device 210 of the other wireless communication system 20) exist simultaneously and the estimated values ​​of the plurality of interfered interference signals are subtracted from the interfered received signal, all of the estimated values ​​of the interfered interference signals may be subtracted, or a predetermined number of the estimated values ​​of the interfered interference signals may be subtracted from the estimated values ​​of the plurality of interfered interference signals.

[0243] Similarly, in the second embodiment, the wireless communication device 500 can have the same configuration as the wireless communication device 110 of the seventh embodiment shown in FIG.

[0244] (G-2) Operation of the Seventh Embodiment Next, the operation of the communication system 1 according to the seventh embodiment (the communication processing method according to the embodiment) will be described with respect to differences from the fifth embodiment.

[0245] Fig. 25 is a flowchart showing the operation of the wireless communication device 110 constituting the wireless communication system 10 according to the seventh embodiment. In Fig. 25, the same or corresponding step numbers as those in Fig. 20 above are assigned to steps that are the same as or correspond to those in Fig. 20 above.

[0246] 25 differs from the fifth embodiment (FIG. 20) in that steps S101, S102, and S105D are excluded and step S108 is replaced with step S108F.

[0247] In step S108F, the interference information providing means 302 of the own wireless communication system 10 provides the obtained transmission signal and an estimate of the amount of interference to the wireless communication device 210 of the other wireless communication system 20 to the interference removal device 240.

[0248] FIG. 26 is a flowchart showing the operation of the interference removal device 240 according to the seventh embodiment.

[0249] The flowchart in FIG. 26 differs from the flowchart in the fifth embodiment (the flowchart in FIG. 8 according to the first embodiment) in that steps S201 and S203 are replaced with S201F and S203F, respectively.

[0250] It is assumed that the interference removal device 240 starts processing, and the interference information acquisition means 241 acquires the transmission signal of the own wireless communication system 10 and the attribute of the transmission signal of the own wireless communication system 10 from the wireless communication device 110 of the own wireless communication system 10 (S201F).

[0251] Then, it is assumed that the interference signal acquisition means 242 acquires the received signal of the other wireless communication system 20 (the signal that is the result of interference with the signal of the wireless communication system 10 itself) (S202).

[0252] When the processing of steps S201F and S202 is completed, the interference signal removal means 243 extracts the reception signal (desired signal) of the other wireless communication system 20 by estimating and removing the interference signal (interference signal from its own wireless communication system 10) included in the reception signal of the other wireless communication system 20, and returns the extracted reception signal (desired signal) to the wireless communication device 210 (the demodulation processing means 2012 of the wireless communication unit 201) (S203F). At this time, the interference signal removal means 243 cannot acquire an estimate of the amount of interference from the other wireless communication system 20 to the wireless communication device 210, and therefore performs processing to estimate and remove the interference signal from its own wireless communication system 10 based on the transmission signal of its own wireless communication system 10 and the attribute of the transmission signal of its own wireless communication system 10.

[0253] (G-3) Effects of the Seventh Embodiment According to the seventh embodiment, the following effects can be achieved, similar to the first and fifth embodiments.

[0254] In the seventh embodiment, the wireless communication device 110 of the own wireless communication system 10 acquires the attributes of the transmission signal of the wireless communication device 110 of the own wireless communication system 10 (interference signal to the wireless communication device 210 of the other wireless communication system 20) and provides it to the interference removal device 240 connected to the wireless communication device 210 of the other wireless communication system 20, thereby correctly estimating the interference signal from the own wireless communication system 10 (interfering side), thereby reducing the residual interference signal and ensuring interference removal performance.

[0255] In the seventh embodiment, a case where the attribute of a transmission signal of the wireless communication device 110 of the own wireless communication system 10 (an interference signal to the wireless communication device 210 of the other wireless communication system 20) is the interference start time on the interfered side of the transmission signal is taken as an example. Since there are many wireless communication devices 110 (interfering side) of the own wireless communication system 10 mounted on the roadside infrastructure 130 and the vehicle 120, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering side) of the own wireless communication system 10, and even when many interfering signals are added together and received on the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), it is possible to correctly determine the interference start time on the interfered side of the transmission signal and remove the interfering signal from the own wireless communication system 10 (interfering side). As a result, in the seventh embodiment, by correctly estimating the interfering signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interference signal and ensure interference removal performance.

[0256] In the seventh embodiment, an example of the attribute of the transmission signal of the wireless communication device 110 of the own wireless communication system 10 (interference signal to the wireless communication device 210 of the other wireless communication system 20) is the carrier frequency difference of the transmission signal of the wireless communication device 110 of the own wireless communication system 10. Since the vehicle 120 of the own wireless communication system 10 and the vehicle 220 of the other wireless communication system 20 move, the wireless communication device 110 (interfering side) of the own wireless communication system 10 that receives interference from the wireless communication device 210 (interfered side) of the other wireless communication system 20 is not specified, and it is impossible to adjust the wireless communication device so that the frequency difference is negligible by selecting a crystal device in advance.Furthermore, since there are many wireless communication devices 110 (interfering sides) of the own wireless communication system 10 installed in roadside infrastructure and vehicles, the wireless communication device 210 (interfered side) of the other wireless communication system 20 receives interference from many wireless communication devices (interfering sides) of the own wireless communication system 10, and so ...110 of the own wireless communication system 10 receives many interference signals added together and receives them at the interfered side (when multiple signals with different phases are added together, the amplitude may become 0), and even in this case, the wireless communication device 110 of the own wireless communication system 10 can estimate and correct the frequency difference by detecting the phase difference between received symbols for each interference signal on the receiving side (interfered side). As a result, in the seventh embodiment, by correctly estimating the interference signal from the own wireless communication system 10 (interfering side), it is possible to reduce the residual interference signal and ensure interference removal performance.

[0257] In the second embodiment, the same effects as those described above can be achieved even when the same configuration as the wireless communication device 110 of the seventh embodiment shown in FIG. 24 is applied to the wireless communication device 500. [Explanation of symbols]

[0258] 1...communication system, 10...own wireless communication system, 20...other wireless communication system, 101...wireless communication unit, 1011...antenna, 1012...demodulation processing means, 1013...modulation processing means, 110...wireless communication device, 120...vehicle, 130...roadside infrastructure, 140...interference management device, 141...interference status acquisition means, 142...interference amount providing means, 143...interference amount estimation means, 201...wireless communication unit, 210...wireless communication device, 2011...antenna, 2012...demodulation processing means 2013...modulation processing means, 220...vehicle, 230...roadside infrastructure, 240...interference removal device, 241...interference information acquisition means, 242...interference signal acquisition means, 243...interference signal removal means, 300...radio interference control unit, 301...transmission signal acquisition means, 302...interference information providing means, 303...signal attribute acquisition means, 304...interference amount acquisition means, 305...interference attribute acquisition means, 306...interference status providing means, 307...interference amount acquisition means, 400...communication path, 500...wireless communication device

Claims

1. A communication system including a first wireless communication system having a plurality of first wireless communication devices arranged in vehicles or road facilities on a road, and a second wireless communication system having a plurality of second wireless communication devices arranged in vehicles or road facilities on the road, A transmission signal acquisition means for acquiring the transmission signal of the first wireless communication device, A signal attribute acquisition means for acquiring the attributes of the interference signal received by the second wireless communication device by the transmission signal, Based on the attributes of the transmitted signal and the interference signal, the second wireless communication device performs a signal estimation process to estimate the component of the interference signal included in the wireless signal received by the second wireless communication device, and based on the result of the signal estimation process, the second wireless communication device performs an interference signal removal means to remove the component of the interference signal from the wireless signal received by the second wireless communication device. A communication system characterized by having the following features.

2. The second wireless communication device further comprises an interference rejection device that removes the component of the interference signal from the first wireless communication device from the wireless signal received by the second wireless communication device, The first wireless communication device is the transmission signal acquisition means; The signal attribute acquisition means, The device includes at least an interference information providing means that provides information on the attributes of the transmission signal and the interference signal to the interference removal device, The interference removal device has the interference signal removal means. The communication system according to feature 1.

3. An interference rejection device that removes the component of the interference signal from the first wireless communication device from the wireless signal received by the second wireless communication device, The system further comprises a third wireless communication device located near the second wireless communication device and capable of communicating with the first wireless communication device, The interference removal device comprises the interference signal removal means, The third wireless communication device is The aforementioned transmission signal acquisition means, The signal attribute acquisition means, The device includes at least interference information providing means that provides information on the attributes of the transmission signal and the interference signal to the interference removal device. The communication system according to feature 1.

4. The first wireless communication device is Interference amount acquisition means for acquiring the amount of interference from the second wireless communication device in the first wireless communication device, The system further includes interference amount estimation means for obtaining an estimated value of the amount of interference applied from the first wireless communication device to the second wireless communication device based on the amount of interference received, The interference information providing means further provides the interference removal device with an estimated value of the amount of interference, The interference signal removal means performs the signal estimation process based on the transmitted signal, the interference signal, and the estimated value of the given interference amount. The communication system according to claim 2, characterized in that it is the same as described in claim 2.

5. The first wireless communication system further includes an interference management device for managing interference conditions, The first wireless communication device further includes interference attribute acquisition means for acquiring interference amount attributes from the second wireless communication device to the first wireless communication device, and interference state provision means for providing at least the interference amount attributes to the interference management device, The interference management device includes interference amount estimation means that performs interference amount estimation processing to estimate the amount of interference applied from the first wireless communication device to the second wireless communication device based on the interference amount attribute and obtains the estimated value of the interference amount. The first wireless communication device further comprises interference amount acquisition means for acquiring an estimated value of the amount of interference from the interference management device, The interference information providing means further provides the estimated value of the amount of interference to the interference removal device. The interference signal removal means performs the signal estimation process based on the transmitted signal, the interference signal, and the estimated value of the given interference amount. The communication system according to feature 2.

6. The first wireless communication device further includes interference amount acquisition means for acquiring the amount of interference from the second wireless communication device to the first wireless communication device, The interference state providing means further provides the amount of interference to the interference management device, The interference amount estimation means performs the interference amount estimation process based on the amount of interference and the attributes of the amount of interference. The communication system according to claim 5, characterized in that it is the same as described in claim 5.

7. A communication method performed by a communication system including a first wireless communication system having a plurality of first wireless communication devices arranged on vehicles or road facilities on a road, a second wireless communication system having a plurality of second wireless communication devices arranged on vehicles or road facilities on the road, and an interference removal device that removes interference signal components from the first wireless communication devices from wireless signals received by the second wireless communication devices, The aforementioned communication system includes means for acquiring a transmission signal, means for acquiring signal attributes, and means for removing interference signals. The transmission signal acquisition means acquires the transmission signal of the first wireless communication device, The signal attribute acquisition means acquires the attributes of the interference signal received by the second wireless communication device by the transmitted signal, The interference signal removal means performs a signal estimation process to estimate the component of the interference signal included in the radio signal received by the second wireless communication device based on the attributes of the transmitted signal and the interference signal, and removes the component of the interference signal from the radio signal received by the second wireless communication device based on the result of the signal estimation process. A communication method comprising:

8. In a communication system comprising a first wireless communication system comprising a plurality of first wireless communication devices arranged on vehicles or road equipment on a road, a second wireless communication system comprising a plurality of second wireless communication devices arranged on vehicles or road equipment on a road, and an interference rejection device that removes interference signal components from the first wireless communication devices from the wireless signals received by the second wireless communication devices, Interference signal removal means: Holds the transmission signal of the first wireless communication device and the attributes of the interference signal received by the second wireless communication device by the transmission signal; performs a signal estimation process to estimate the component of the interference signal included in the wireless signal received by the second wireless communication device based on the attributes of the transmission signal and the interference signal; and removes the component of the interference signal from the wireless signal received by the second wireless communication device based on the result of the signal estimation process. An interference removal device comprising:

9. A computer mounted on an interference rejection device that constitutes a communication system comprising: a first wireless communication system comprising a plurality of first wireless communication devices arranged on vehicles or road equipment on a road; a second wireless communication system comprising a plurality of second wireless communication devices arranged on vehicles or road equipment on a road; and an interference rejection device that removes interference signal components from the first wireless communication devices from the wireless signals received by the second wireless communication devices, Interference signal removal means: Holds the transmission signal of the first wireless communication device and the attributes of the interference signal received by the second wireless communication device by the transmission signal; performs a signal estimation process to estimate the component of the interference signal included in the wireless signal received by the second wireless communication device based on the attributes of the transmission signal and the interference signal; and removes the component of the interference signal from the wireless signal received by the second wireless communication device based on the result of the signal estimation process. The interference removal program is characterized by causing the program to function as follows.

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