Wireless transmission device, wireless reception device, wireless relay device, control circuit, storage medium, communication system, and communication method

Abstract

A wireless transmission device (1) comprises: wired reception units (101A, 101B) for receiving a wired signal, which is a signal transmitted in a wired manner and is configured from a plurality of frames; a wireless control signal addition unit (103) for inserting a wireless control signal, which is a control signal for managing wireless communication, in a section in which information is not transmitted between frames of the received wired signal; and a wireless signal generation unit (104) for generating a wireless signal to be wirelessly transmitted by using the wireless control signal and a reception bit pattern of the wired signal.

Description

Radio transmitting device, radio receiving device, radio relay device, control circuit, storage medium, communication system, and communication method

[0001] The present disclosure relates to a wireless transmitting device, a wireless receiving device, a wireless relay device, a control circuit, a storage medium, a communication system, and a communication method for converting part of wired communication into wireless communication.

[0002] Various technologies are known for converting wired communications to wireless. It is necessary to appropriately select the frequency band and medium to be used depending on the requirements and conditions of the wireless system. For example, Patent Literature 1 discloses a technology for converting wired signals into millimeter waves for wireless transmission. Millimeter waves are suitable for high-capacity, low-latency wireless transmission because they are less likely to interfere with other communications due to their high line-of-sight characteristics and can easily secure a wide bandwidth.

[0003] Japanese Patent Application Laid-Open No. 2018-014716

[0004] However, the above-mentioned conventional technology only discloses re-modulating a wired signal into a wireless bit pattern and transmitting it, and there was a problem in that it was not possible to perform communication management such as measuring communication quality or adjusting communication rate in the wireless transmission section.

[0005] The present disclosure has been made in view of the above, and aims to provide a wireless transmission device that enables communication management in a wireless transmission section in which part of wired communication is wirelessized.

[0006] In order to solve the above-mentioned problems and achieve the objectives, the wireless transmission device of the present disclosure is characterized by comprising a wired receiving unit that receives a wired signal that is a signal transmitted via a wire and is composed of a plurality of frames, a wireless control signal providing unit that inserts a wireless control signal, which is a control signal for wireless communication management, into a section where no information transmission is taking place between frames of the received wired signal, and a wireless signal generating unit that generates a wireless signal to be transmitted wirelessly using the received bit pattern of the wired signal and the wireless control signal.

[0007] The wireless transmission device according to the present disclosure has an effect of enabling communication management in a wireless transmission section in which part of wired communication is made wireless.

[0008] 1 is a diagram showing a functional configuration of a wireless transmission device according to a first embodiment; 2 is a diagram showing a wired signal received by a wireless transmission device and a wireless signal transmitted by the wireless transmission device when an Ethernet frame is used; 3 is a diagram showing a functional configuration of a wireless reception device according to a first embodiment; 4 is a diagram showing an example of a configuration of a communication system including a wireless transmission device and a wireless reception device; 5 is a diagram showing an example of a configuration of a communication system including a wireless transmission device, a wireless reception device, and a wireless relay device; 6 is a diagram showing a functional configuration of a wireless relay device according to a second embodiment;

[0009] Hereinafter, a wireless transmitting device, a wireless receiving device, a wireless relay device, a control circuit, a storage medium, a communication system, and a communication method according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] 1 is a diagram illustrating a functional configuration of a wireless transmission device 1 according to a first embodiment. The wireless transmission device 1 is an example of a communication device having a function of receiving a wired signal, which is a signal transmitted via a wire, and a function of converting the wired signal into a wireless signal and transmitting it wirelessly.

[0011] The wireless transmission device 1 includes wired receiving units 101A and 101B, a wired signal detection unit 102, a wireless control signal providing unit 103, a wireless signal generation unit 104, a wireless transmission unit 105, and a transmission antenna unit 106. Note that the wired receiving units 101A and 101B perform similar processing, and therefore, hereinafter, when there is no need to particularly distinguish between the wired receiving units 101A and 101B, they may be simply referred to as the wired receiving unit 101. Note that the signal system of the wired signal received by the wired receiving unit 101A is referred to as signal system #A, and the signal system of the wired signal received by the wired receiving unit 101B is referred to as signal system #B.

[0012] The wired receiving unit 101 receives a wired signal. The wired receiving unit 101 performs wired communication according to a communication method such as Ethernet (registered trademark), RS-232C, RS-422, or RS-485. These communication methods all perform burst transmission in which frames are used as a single block of data for wired communication. The wired receiving unit 101 generates demodulated data of the received wired signal and outputs the bit strings of the generated demodulated data to the wired signal detection unit 102 and the wireless signal generation unit 104, respectively.

[0013] The wired signal detection unit 102 detects a section where no information is transmitted between frames of the wired signal received by the wired receiving unit 101. The wired signal detection unit 102 outputs information indicating the detected section to the wireless control signal providing unit 103.

[0014] FIG. 2 illustrates a wired signal received by a wireless transmission device 1 and a wireless signal transmitted by the wireless transmission device 1 when Ethernet frames are used. The wired signal received by the wireless transmission device 1 is composed of multiple wired frames. Each wired frame can include a preamble, a header, a payload, and a checksum. In this example, the wired frame is an Ethernet frame. In the case of Ethernet, the presence of an Ethernet frame is recognized using a predetermined bit pattern called a Start Frame Delimiter (SFD) present in the preamble or in the header received following the preamble. The payload in the Ethernet frame is then decoded and the payload data is passed to a higher layer. One burst is composed of Ethernet frames. Between frames, there is a guard time interval called an Inter Packet Gap (IPG) or Inter Frame Gap (IFG). While no significant Ethernet frames exist in this interval, synchronization signals between transmitter and receiver may be transmitted in the wired physical layer. In a typical Ethernet PHY module, only the Ethernet frame portion excluding the guard time interval, which is the synchronization signal, is passed to the function responsible for the MAC (Media Access Control) layer. Therefore, from the perspective of the MAC layer, this guard time interval is determined to be an interval where there is no signal, i.e., an interval where no information is being transmitted.

[0015] In addition, in RS-232C, a block of data surrounded by a start bit and a stop bit is transmitted as one burst, and the period from the stop bit to the next start bit is a guard time period during which no information is transmitted.

[0016] The wired signal detection unit 102 outputs information indicating a section in which no information transmission between frames of the wired signal is performed as described above to the wireless control signal providing unit 103. The "information indicating a section in which no information transmission between frames of the wired signal is performed" may be, for example, information indicating a section in which a wired burst exists, and a section other than a section in which a wired burst exists may be determined to be a "section in which no information transmission between frames of the wired signal is performed."

[0017] The wireless control signal providing unit 103 inserts a wireless control signal, which is a control signal for wireless use, into a section where no information is transmitted between frames of the wired signal. The wireless control signal is composed of one or more wireless control information frames. As shown in FIG. 2 , the wireless control information frame includes a wireless preamble, a wireless header, and wireless control information. Note that although it has been stated that a wireless control signal is inserted into a section where no information is transmitted, if the wired signal includes a long preamble such as an Ethernet frame and the header includes information indicating the start position of the frame body, such as an SFD, then a portion of the preamble of the wired frame may be overwritten with the wireless control signal, as shown in FIG. 2 . The wireless signal includes information included in the wired frame of the wired signal and the wireless control signal. In the example shown in FIG. 2 , a portion of the preamble of wired frame #2 is overwritten with the wireless control signal. In this case, it is possible to transmit a wireless control signal that is longer than the guard time section by the length of the overwritten section. If a portion of the preamble of the wired frame is overwritten with the wireless control signal, a valid wired signal can be restored by re-adding the preamble to the beginning when the SFD is received on the receiving side.

[0018] The wireless signal generating unit 104 generates a wireless signal to be wirelessly transmitted by the wireless transmitting unit 105, using the reception bit pattern of the wired signal received by the wired receiving unit 101 and the wireless control signal inserted by the wireless control signal adding unit 103. The wireless signal generating unit 104 outputs the generated wireless signal to the wireless transmitting unit 105.

[0019] The wireless transmitting unit 105 wirelessly transmits the wireless signal generated by the wireless signal generating unit 104 via the transmitting antenna unit 106. As a result, the wireless signal transmitted from the wireless transmitting device 1 has a wireless control signal inserted in a section where no information is transmitted between wired frames of the wired signal, as shown in FIG.

[0020] Ethernet frames often have an error detection function called a Frame Check Sequence (FCS) using a Cyclic Redundancy Check (CRC). However, when converting a wired signal to a wireless signal, the wireless transmission device 1 does not necessarily need to perform a CRC check and remove frames in which errors are detected. This is because if all frames are received before the CRC calculation is completed and then a decision is made as to whether to send the frames before sending them to a subsequent stage, a large delay will occur. The CRC check can be performed by a communication device that performs upper layer processing; error detection does not need to be performed within a device that relays and transfers Ethernet frames, etc., as is, such as the wireless transmission device 1.

[0021] An example of radio control information included in a radio control signal is a known sequence for channel estimation, such as BPSK (Binary Phase Shift Keying), required for synchronous detection. If the phase rotation of the known sequence can be corrected on the receiving side, synchronous detection can be achieved, and signal multiplexing using QPSK (Quadrature Phase Shift Keying) or spreading codes, as described below, can also be realized. Furthermore, transmitting a known sequence as radio control information enables measurement of signal and noise levels based on the reception results of the known sequence, making it possible to use adaptive modulation, which uses a modulation method appropriate for the reception environment. For example, if the received signal-to-noise ratio (SNR) is lower than a threshold, a noise-resistant modulation method such as BPSK or binary ASK may be used, and if the received SNR exceeds the threshold, multi-level transmission may be performed. In this case, transmission parameters such as a modulation method may also be stored as radio control information.

[0022] The radio control information frame may include the above-mentioned known sequence, transmission parameters, etc. as radio control information. The radio control information frame may include information indicating that the frame is dedicated to radio control, the type of control information, and the control information itself. In this case, if the application transmitting and receiving the original wired frame aims to minimize the transmission delay of the wired frame, if the next wired frame arrives during the transmission of the radio control information, reception of the radio control information frame must be interrupted midway to avoid loss of information in the wired frame. Therefore, it is preferable to configure the frame size of the radio control information as small as possible. If a sufficient delay can be added, loss of the radio control information frame can be avoided. However, there is a trade-off between the amount of delay and the frame size of the radio control information frame. Therefore, when transmitting these in a time-division manner as shown in Figure 2, it is necessary to either add a delay to ensure the frame size of the radio control information frame or allow the radio control information frame to be interrupted to prevent an increase in delay.

[0023] It is desirable for the wireless control information frame to be a frame of a different format from the wired frame. However, if the duty ratio of the wired signal is small and the possibility of interruption is low even if the frame size of the wireless control information frame is set large, the wireless control information frame may be a frame of a format such as an Ethernet frame having a long preamble and header similar to that of the wired frame. For example, if an Ethernet frame is transmitted via a wired line and it is known that the time occupancy rate of the wired frame is not high in the system, for example, if it is known that the wireless has a transmission capacity of 1 Gbps but the Ethernet is limited to a rate of up to 100 Mbps, the duty ratio of the wired signal is likely to be small. If it is possible to distinguish in the header whether the information is contained in the original wired frame or information added when converting to a wireless signal, the receiving side can be configured to select and output only the information contained in the wired frame. Furthermore, if the duty ratio of the wired signal is expected to be high, a configuration in which a data block with a small header, such as 64b / 66b, is used as one wireless control information frame is also conceivable. The radio control information frame may have any structure other than the above example, as long as it can be identified from the information contained in the wired signal on the receiving side.

[0024] Alternatively, the wireless transmission device 1 may process multiple signal systems received in parallel in the wired signal detection unit 102 and the wireless control signal assigning unit 103, and multiplex the multiple signal systems in the wireless signal generation unit 104. In the example of FIG. 1 , the wireless transmission device 1 receives signal system #A and signal system #B, so the wired signal detection unit 102 and the wireless control signal assigning unit 103 process signal system #A and signal system #B in parallel, and the wireless signal generation unit 104 multiplexes signal system #A and signal system #B. When multiplexing multiple signal systems, the wireless transmission rate must be equal to or greater than the sum of the transmission rates of each wired connection. When multiplexing two signal systems, a possible multiplexing method is to map the sequences of each signal system to the real and imaginary axes using a transmission method that provides orthogonal channels, such as QPSK. When multiplexing two or more signal systems, a possible method is to use a method that assigns multiple bits to each of the real and imaginary axes, such as 64QAM (Quadrature Amplitude Modulation). In 64QAM, three bits can be assigned to each of the real and imaginary axes, allowing up to six signal systems to be accommodated. It is also possible to multiplex multiple signal systems using a spread multiplexing method that uses orthogonal codes. One example of a spread code is a method that uses Walsh codes, which have good cross-correlation characteristics. Multiplexing multiple signal systems using the above-mentioned QPSK, 64QAM, spread codes, etc., makes it possible to transmit signals while suppressing delay fluctuations in each signal system.

[0025] Another method for multiplexing multiple signal systems is to switch and map the signal system assigned to each wireless modulation symbol or bit, as in parallel-to-serial (P / S) conversion. In this case, as with multiplexing by spreading, a sufficiently high wireless transmission speed is required. When performing P / S conversion, data must be supplied even in sections where no information is transmitted in a specific signal system. However, as described above, by inserting a wireless control signal into a section where no information is transmitted by a wired signal, the section where no information is transmitted can be eliminated, and the original signal sequence can be correctly restored on the receiving side.

[0026] 3 is a diagram illustrating a functional configuration of the wireless receiving device 3 according to the first embodiment. The wireless receiving device 3 is an example of a communication device having a function of receiving a wireless signal transmitted by the wireless transmitting device 1, converting the received wireless signal into a wired signal, and transmitting the wired signal.

[0027] The wireless receiving device 3 includes a receiving antenna section 300 , a wireless receiving section 301 , a demodulating section 302 , a wireless control signal processing section 303 , a wired signal generating section 304 , wired transmitting sections 305 A and 305 B, and a display section 306 .

[0028] The wireless receiving section 301 receives the wireless signal emitted into the air as a radio wave by the wireless transmitting device 1 using the receiving antenna section 300 and outputs the received signal to the demodulating section 302 .

[0029] The demodulation unit 302 performs demodulation processing on the received signal corresponding to the modulation method used on the transmitting side, and outputs the bit strings resulting from the demodulation to the wired signal generation unit 304 and the wireless control signal processing unit 303. If the modulation method is fixed, the demodulation unit 302 performs demodulation processing using the fixed demodulation method, thereby enabling the data included in the received signal to be correctly demodulated.

[0030] If the modulation method is variable, the modulation method used on the transmitting side is stored in the wireless control signal, but the modulation method is unknown until the wireless control signal processing unit 303 decodes the modulation method stored in the wireless control signal. Therefore, for example, it is possible to fix only the modulation method of the wireless control signal. In this case, the demodulation unit 302 performs demodulation processing corresponding to a predetermined modulation method on the wireless control signal, decodes the modulation method for the signal sequence included in the wired frame, and performs demodulation processing corresponding to the decoded modulation method. It is also possible to limit the number of candidate modulation methods for the wireless control signal to about two. In this case, the demodulation unit 302 may perform demodulation processing corresponding to each of the predetermined candidate modulation methods, attempt to decode each demodulation result, and adopt the demodulation result whose header can be read.

[0031] The radio control signal processing unit 303 can perform processing based on the radio control signal. For example, if the radio control signal includes a known pilot signal, the radio control signal processing unit 303 can measure communication quality using the received pilot signal. Furthermore, in a BPSK modulation system, if the radio control signal includes a known sequence for channel estimation, the radio control signal processing unit 303 can observe the phase rotation of the known sequence and apply feedback to the downconverter of the demodulation unit 302, thereby achieving a synchronous detection function including phase tracking, such as a phase-locked loop (PLL). Furthermore, the radio control signal processing unit 303 can measure the SNR using the known signal included in the radio control signal and treat the SNR as an indicator of communication quality. Furthermore, the radio control signal processing unit 303 can perform error detection from the demodulation result of the known signal included in the radio control signal and treat the error detection result as an indicator of communication quality. For example, if the radio control signal processing unit 303 determines that reception of multiple consecutive frames has failed, it can display communication error information using the display unit 306. The display unit 306 may be a display device such as an LED (Light Emitting Diode), or may be an interface that outputs information to an external device such as a serial console. The display unit 306 may display not only the wireless control signal but also the FCS result of the wired frame. In this case, the wireless control signal processing unit 303 also reads the wired frame from the data obtained from the demodulation unit 302 and performs FCS.

[0032] The wired signal generation unit 304 extracts the original wired frame by removing the wireless control signal from the received signal, and generates a wired signal that is a signal to be transmitted via a wire. The wired signal generation unit 304 outputs the generated wired signal to either the wired transmission unit 305A or 305B. The wired transmission unit 305A, which is the output destination of the wired signal generation unit 304, corresponds to the wired reception unit 101A of the wireless transmission device 1, and the wired transmission unit 305B corresponds to the wired reception unit 101B of the wireless transmission device 1. In other words, the wired transmission unit 305A corresponds to signal system #A, and the wired transmission unit 305B corresponds to signal system #B. From the perspective of the wired transmission section, the wired reception unit 101A and the wired transmission unit 305A are directly connected, and the wired reception unit 101B and the wired transmission unit 305B can be treated as if they were directly connected, without being aware of the presence of a wireless transmission path between them. The wired signal generating unit 304 can select the output destination of the received signal from the wired transmitting unit 305A, 305B based on, for example, address information included in the Ethernet frame. In the case of a communication method in which address information cannot be assigned, such as RS-232C, the wireless control signal processing unit 303 outputs information that enables the wired signal generating unit 304 to determine the output destination of each signal sequence, thereby allowing the wired signal generating unit 304 to select the output destination of the generated wired signal. Note that if the preamble of the original wired signal is overwritten when the wireless control signal is inserted, the wired signal generating unit 304 can restore the original wired signal by re-assigning the preamble, which is a predetermined sequence, based on the position of the SFD.

[0033] Although the wireless transmitting device 1 shown in FIG. 1 and the wireless receiving device 3 shown in FIG. 3 are shown to have two signal systems transmitted via wired communication, the number of signal systems may be one, or three or more.

[0034] 4 is a diagram showing an example configuration of a communication system 10A including a wireless transmitting device 1 and a wireless receiving device 3. The communication system 10A includes one wireless transmitting device 1 and one wireless receiving device 3 that receives a wireless signal transmitted by the wireless transmitting device 1. The wireless transmitting device 1 converts a wired signal into a wireless signal and transmits it wirelessly, while the wireless receiving device 3 receives the wireless signal, converts it into a wired signal, and transmits it via wire. At this time, the wireless transmitting device 1 inserts a wireless control signal, which is a control signal for wireless use, into a section in which no information transmission is performed between multiple frames included in the wired signal, thereby enabling wireless control information for performing various controls in the wireless transmission section to be transmitted to the wireless receiving device 3. The wireless receiving device 3 removes the wireless control signal from the received signal to restore the original wired signal, i.e., the wired signal received by the wireless transmitting device 1, and transmits it via wire.

[0035] Although omitted for simplicity in Fig. 4, a plurality of devices are connected in the wired transmission section, including a source device and a destination device of the wired signal of each signal system. As described above, the wired signal transmitted in the wired transmission section does not change before and after the wireless transmission section, so each device connected in the wired transmission section can operate without being aware of the existence of the wireless transmission section, that is, in the wireless transmission section, in the same way as if it were connected by wire instead of wirelessly.

[0036] As described above, the wireless transmission device 1 according to the first embodiment is characterized by including wired receiving units 101A and 101B that receive a wired signal that is a signal transmitted via a wire and is composed of a plurality of frames, a wireless control signal providing unit 103 that inserts a wireless control signal, which is a control signal for wireless communication management, into a section where no information transmission occurs between frames of the received wired signal, and a wireless signal generating unit 104 that generates a wireless signal to be transmitted wirelessly using a received bit pattern of the wired signal and the wireless control signal. With this configuration, when the wireless transmission device 1 receives a wired signal, it transmits a wireless signal in which a wireless control signal, which is a control signal for wireless communication management, is inserted into a section where no information transmission occurs between frames of the wired signal. Therefore, in a wireless transmission section where part of the wired communication is wireless, wireless communication management of the wireless transmission section can be performed using the wireless control signal. Wireless communication management refers to understanding the communication environment, such as the communication quality of the wireless transmission section, and adjusting parameters related to wireless communication, such as the communication rate. This makes it possible to monitor the wireless communication environment externally, identify the cause of communication problems, and check the communication status when a communication failure occurs. It also provides a means for selecting the wireless transmission mode according to the communication quality, making it possible to flexibly provide various communication functions such as adjusting the transmission rate and signal multiplexing.

[0037] Here, the wireless signal generating unit 104 can generate a wireless signal including a wireless control signal that is longer than the section in which no information is transmitted between frames of the wired signal by overwriting the preamble included in the frame with a wireless control signal.

[0038] Furthermore, even if the wired signal includes an error detection code, the wireless transmission device 1 does not need to perform error detection processing, which makes it possible to suppress the occurrence of delay jitter and easily achieve low delay, low delay fluctuation, and high communication quality.

[0039] The wireless transmission device 1 also includes multiple wired receiving units 101A, 101B corresponding to the multiple signal systems, respectively, and one wireless transmission unit 105 for transmitting wireless signals. The wireless signal generation unit 104 multiplexes the multiple signal systems to generate a wireless signal, and the single wireless transmission unit 105 can multiplex and transmit the multiple signal systems. While a wired system requires one wire for each signal system, the wireless transmission device 1 makes it possible to transmit and receive multiple signal systems using a single antenna. In this case, by using a channel that controls interference between the signal systems, it is possible to suppress the effects of interference and maintain communication quality even when multiple signal systems are simultaneously transmitted and received using a single antenna.

[0040] The frames constituting the wired signal may be Ethernet frames.

[0041] Furthermore, according to the first embodiment, the wireless receiving device 3 that receives the wireless signal transmitted by the wireless transmitting device 1 can include a wireless control signal processing unit 303 that performs wireless communication management in the wireless transmission section of the wireless signal based on the wireless control signal included in the wireless signal. This enables the receiving side to perform wireless communication management in the wireless transmission section based on the wireless control signal inserted on the transmitting side. For example, the wireless control signal processing unit 303 can perform at least one of measuring wireless communication quality in the wireless transmission section and controlling the operation of reception processing of the wireless signal transmitted by the wireless transmitting device 1, as the wireless communication management.

[0042] Furthermore, the wireless receiving device 3 may further include a wired signal generating unit 304 that removes the wireless control signal from the received wireless signal to restore the wired signal received by the wireless transmitting device 1, and wired transmitting units 305A and 305B that transmit the restored wired signal via a wire. As a result, the wired signal received by the wireless transmitting device 1 and the wired signal transmitted by the wireless receiving device 3 become identical, and the source device and destination device of the wired communication can communicate in the same manner as if they were all connected by wire, without recognizing that part of the communication path between the source device and the destination device is connected wirelessly.

[0043] As described above, the preamble portion of a frame may be overwritten in the wireless transmitting device 1, but if the wired signal generating unit 304 of the wireless receiving device 3 cannot detect a preamble of a predetermined bit pattern in the information transmission frame portion of the received wireless signal, the wired signal is restored by re-adding the preamble. Therefore, even if the preamble portion of the frame is overwritten by a wireless control signal in the wireless transmitting device 1, the original wired signal can be reliably restored.

[0044] Furthermore, the functions of the wireless transmission device 1 according to the first embodiment can be realized using a control circuit, as will be described later. This control circuit controls the wireless transmission device 1, which receives a wired signal that is a signal transmitted via a wire and is composed of a plurality of frames, converts the wired signal into a wireless signal, and transmits the wireless signal, and can cause the wireless transmission device 1 to execute a step of inserting a wireless control signal, which is a control signal for managing wireless communication, into a section between frames of the received wired signal where no information transmission is performed.

[0045] It is also possible to provide a storage medium for realizing the functions of the wireless transmission device 1 according to the first embodiment. This storage medium stores a program for controlling the wireless transmission device 1 that receives a wired signal that is a signal transmitted over a wire and is made up of a plurality of frames, converts the wired signal into a wireless signal, and transmits the wireless signal, and the program causes the wireless transmission device 1 to execute a step of inserting a wireless control signal, which is a control signal for wireless communication, into a section between frames of the received wired signal where no information transmission is taking place.

[0046] In addition, the communication system 10A according to the first embodiment makes part of wired communication wireless, and includes a wireless transmitting device 1 that receives a wired signal that is a signal transmitted via a wire and is composed of a plurality of frames, generates a wireless signal by inserting a wireless control signal, which is a control signal for wireless communication, into a section where information transmission between frames of the received wired signal is not performed, and transmits the generated wireless signal, and a wireless receiving device 3 that receives the wireless signal transmitted by the wireless transmitting device 1, performs wireless communication management in the wireless transmission section by the wireless signal based on the wireless control signal contained in the received wireless signal, removes the wireless control signal from the received wireless signal, restores the wired signal received by the wireless transmitting device 1, and transmits the restored wired signal via a wired connection.

[0047] Furthermore, according to the first embodiment, it is also possible to provide a communication method for converting part of wired communication to wireless. This communication method includes the steps of: a wireless transmitting device (1) receiving a wired signal that is a signal transmitted via a wire and is composed of a plurality of frames; a wireless transmitting device (1) generating a wireless signal by inserting a wireless control signal, which is a control signal for wireless communication, into a section of the received wired signal where no information transmission is performed between the frames; a wireless transmitting device (1) transmitting the generated wireless signal; a wireless receiving device (3) receiving the wireless signal; a wireless receiving device (3) performing wireless communication management in the wireless transmission section by the wireless signal based on the wireless control signal included in the received wireless signal; a wireless receiving device (3) removing the wireless control signal from the received wireless signal to restore the wired signal received by the wireless transmitting device (1); and a wireless receiving device (3) transmitting the restored wired signal via a wire.

[0048] Second Embodiment In Fig. 4, the radio signal transmitted by the radio transmitting device 1 is transmitted directly to the radio receiving device 3, but the radio signal may be transmitted via the radio relay device 4.

[0049] 5 is a diagram showing an example of the configuration of a communication system 10B including a wireless transmitting device 1, a wireless receiving device 3, and a wireless relay device 4. Note that while the configuration of the communication system 10B including one wireless relay device 4 is shown here, the configuration may also be such that a wireless signal transmitted by the wireless transmitting device 1 is relayed in series by two wireless relay devices 4 and transmitted to the wireless receiving device 3.

[0050] 6 is a diagram showing a functional configuration of the wireless relay device 4 according to the second embodiment. The wireless relay device 4 includes a receiving antenna unit 400, a wireless receiving unit 401, a demodulating unit 402, a wireless control signal processing unit 403, a wireless retransmission signal generating unit 404, a wireless transmitting unit 405, a display unit 406, and a transmitting antenna unit 407.

[0051] The receiving antenna section 400 has the same function as the receiving antenna section 300. The wireless receiving section 401 has the same function as the wireless receiving section 301. The demodulating section 402 has the same function as the demodulating section 302. The display section 406 has the same function as the display section 306.

[0052] In addition to the functions of the radio control signal processing unit 303, the radio control signal processing unit 403 has a function of generating a radio control signal for a signal to be transmitted as a relay signal in the same manner as the radio control signal providing unit 103, and outputting the generated radio control signal as a bit string to the radio retransmission signal generating unit 404. The radio control signal generated by the radio control signal processing unit 403 may be the same as the received radio control signal, or may be the received radio control signal plus information such as the number of relays indicating how many hops the signal will be relayed through. Furthermore, if there is a possibility of interference with other relay links, a different sequence having good orthogonality to the signal of the previous link may be selected as the pilot signal, so that a control signal different from that of the previous link may be sent.

[0053] The radio retransmission signal generation unit 404 generates a radio retransmission signal, which is a signal to be retransmitted as a relay signal, based on the received bit pattern of the radio signal output by the demodulation unit 402 and the bit sequence of the radio control signal output by the radio control signal processing unit 403, and outputs the generated radio retransmission signal to the radio transmission unit 405.

[0054] The wireless transmitting unit 405 has the same function as the wireless transmitting unit 105, and transmits the wireless retransmission signal output by the wireless retransmission signal generating unit 404 using the transmitting antenna unit 407. The transmitting antenna unit 407 has the same function as the transmitting antenna unit 106.

[0055] Although the wireless relay device 4 shown in FIG. 6 has both the function of receiving a wireless signal and the function of transmitting a wireless signal, all of the functions of the wireless relay device 4 do not necessarily have to be housed in a single housing and realized as a single device. For example, the demodulation function on the receiving side and the signal generation function on the transmitting side may be implemented in physically separate locations. For example, the demodulation unit 402 and the wireless retransmission signal generation unit 404 may be connected by a cable of several meters. Similarly, connections between the demodulation unit 402 and the wireless retransmission signal generation unit 404, as well as between any other components, may be made by cables of several meters. This provides the advantage of making it easier to ensure communication performance by combining wired communication, which is more resistant to electromagnetic noise than wireless communication.

[0056] As described above, the wireless relay device 4 of embodiment 2 is a wireless relay device 4 that relays a wireless signal transmitted by the wireless transmission device 1, and can include a wireless retransmission signal generation unit 404 that generates a wireless retransmission signal, which is a wireless signal to be retransmitted, based on the received wireless signal, and a wireless transmission unit 405 that transmits the wireless retransmission signal.

[0057] In addition, the wireless relay device 4 further includes a wireless control signal processing unit 403 that generates a wireless control signal for a wireless retransmission signal by adding information about the number of relays to the wireless control signal contained in the received wireless signal, and the wireless retransmission signal generating unit 404 generates a wireless retransmission signal that includes the wireless control signal generated by the wireless control signal processing unit 403.

[0058] By using the wireless relay device 4, it becomes possible to extend the wireless transmission distance of a wireless signal that is generated by converting a wired signal and that has a wireless control signal inserted therein.

[0059] In the above, the wireless transmitting device 1 having the function of transmitting wireless signals and the wireless receiving device 3 having the function of receiving wireless signals are separate devices, but a single communication device 6 may have both the functions of the wireless transmitting device 1 and the wireless receiving device 3.

[0060] 7 is a diagram showing an example of the configuration of a communication system 10C including communication devices 6A and 6B having bidirectional communication functions. Note that the two communication devices 6 having bidirectional communication functions are distinguished by being referred to as communication devices 6A and 6B. The communication system 10C includes the communication device 6A and the communication device 6B.

[0061] Each of the communication devices 6A and 6B includes a wireless transmitting device 1 and a wireless receiving device 3. The function of the wireless transmitting device 1 is the same as that described with reference to FIG. 1 , and therefore a description thereof will be omitted here. The function of the wireless receiving device 3 is the same as that described with reference to FIG. 3 , and therefore a description thereof will be omitted here. The wireless transmitting device 1 of the communication device 6A converts a wired signal into a wireless signal and transmits the wireless signal wirelessly, and the wireless receiving device 3 of the communication device 6B receives the wireless signal. The wireless receiving device 3 of the communication device 6B can perform various wireless control processes based on the demodulation results of the wireless control signal included in the received wireless signal. The wireless transmitting device 1 of the communication device 6B converts a wired signal into a wireless signal and transmits the wireless signal wirelessly, and the wireless receiving device 3 of the communication device 6A also receives the wireless signal. The wireless receiving device 3 of the communication device 6A can also perform various wireless control processes based on the demodulation results of the wireless control signal included in the received wireless signal. In this way, two-way communication between two points that are part of a wired system can be made wireless by using the communication devices 6A and 6B that include the wireless transmitting device 1 and the wireless receiving device 3. Since a wireless control signal is included in the wireless signal between the communication devices 6A and 6B, various wireless control processes can be realized even when part of the wired communication is made wireless.

[0062] Here, the hardware configuration will be described. Here, as an example, an example of the hardware configuration of a communication device 6 having a bidirectional communication function will be described. Fig. 8 is a diagram showing an example of the hardware configuration. The communication device 6 performs bidirectional communication using FDD (Frequency Division Duplex) or TDD (Time Division Duplex), and has the functions of both the wireless transmitting device 1 and the wireless receiving device 3.

[0063] The communication device 6 includes a wired signal receiving circuit 501 , a wireless control signal processing circuit 502 , a wireless signal transmitting circuit 503 , a wireless signal receiving circuit 504 , and a wired signal transmitting circuit 505 .

[0064] The wired signal receiving circuit 501 has the function of receiving a wired signal and generating demodulated data. The wireless control signal processing circuit 502 has the function of providing a wireless control signal, processing the wireless control signal, and displaying communication quality. The wireless signal transmitting circuit 503 has the function of generating and modulating a wireless signal and converting it to a wireless frequency. The wireless signal receiving circuit 504 has the function of converting a wireless signal from a wireless frequency to a baseband or intermediate frequency and performing demodulation processing. The wired signal transmitting circuit 505 has the function of generating a wired signal and transmitting the generated wired signal. The above functional blocks are interconnected.

[0065] Here, an example of the hardware configuration of a communication device 6 having bidirectional communication capabilities is shown, but it is also possible to configure a wireless transmitting device 1, a wireless receiving device 3, and a wireless relay device 4 by omitting some of these functional blocks.

[0066] The functions of wired receivers 101A and 101B and wired signal detector 102 are realized by wired signal receiver circuit 501. The function of wireless control signal assigner 103 is realized by wireless control signal processing circuit 502. The functions of wireless signal generator 104 and wireless transmitter 105 are realized by wireless signal transmitter circuit 503. In other words, the functions of wireless transmitter 1 can be realized by wired signal receiver circuit 501, wireless control signal processing circuit 502, and wireless signal transmitter circuit 503.

[0067] Furthermore, the functions of wireless receiving section 301 and demodulating section 302 are realized by wireless signal receiving circuit 504. The functions of wireless control signal processing section 303 and display section 306 are realized by wireless control signal processing circuit 502. The functions of wired signal generating section 304 and wired transmitting sections 305A and 305B are realized by wired signal transmitting circuit 505. In other words, the functions of wireless receiving device 3 can be realized by wireless signal receiving circuit 504, wireless control signal processing circuit 502, and wired signal transmitting circuit 505.

[0068] Furthermore, the functions of the wireless receiver 401 and demodulator 402 are realized by the wireless signal receiver circuit 504. The functions of the wireless control signal processor 403 and display 406 are realized by the wireless control signal processing circuit 502. The functions of the wireless retransmission signal generator 404 and wireless transmitter 405 are realized by the wireless signal transmitter circuit 503. In other words, the functions of the wireless relay device 4 can be realized by the wireless signal receiver circuit 504, the wireless control signal processing circuit 502, and the wireless signal transmitter circuit 503.

[0069] Each of the wired signal receiving circuit 501, the wireless control signal processing circuit 502, the wireless signal transmitting circuit 503, the wireless signal receiving circuit 504, and the wired signal transmitting circuit 505 is a processing circuit. These processing circuits may be dedicated hardware or a control circuit using a CPU (Central Processing Unit). If the processing circuit is dedicated hardware, the processing circuit may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. If the processing circuit is a control circuit using a CPU, the processing circuit has a CPU and memory, and the CPU can read and execute programs stored in the memory to realize processing of each component. A CPU is also called an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), etc. The memory may be, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), or EEPROM (Electrically Programmable ROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disk). The memory is also used as temporary memory for each process executed by the CPU. Note that the program executed by the CPU may be provided in a state stored on a storage medium, or may be provided via a network such as the Internet.

[0070] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0071] 1 Wireless transmitting device, 3 Wireless receiving device, 4 Wireless relay device, 6, 6A, 6B Communication device, 10A, 10B, 10C Communication system, 101, 101A, 101B Wired receiving unit, 102 Wired signal detection unit, 103 Wireless control signal providing unit, 104 Wireless signal generating unit, 105, 405 Wireless transmitting unit, 106, 407 Transmitting antenna unit, 300, 400 Receiving antenna unit, 301, 401 Wireless receiving unit, 302, 402 Demodulation unit, 303, 403 Wireless control signal processing unit, 304 Wired signal generating unit, 305A, 305B Wired transmitting unit, 306, 406 Display unit, 404 Wireless retransmission signal generating unit, 501 Wired signal receiving circuit, 502 Wireless control signal processing circuit, 503 Wireless signal transmitting circuit, 504 Wireless signal receiving circuit, 505 wired signal transmitting circuit.

Claims

1. A wireless transmitting device comprising: a wired receiving unit that receives a wired signal that is transmitted via a wire and is composed of a plurality of frames; a wireless control signal providing unit that inserts a wireless control signal, which is a control signal for managing wireless communications, into a section in which no information is transmitted between frames of the received wired signal; and a wireless signal generating unit that generates a wireless signal to be transmitted wirelessly using a received bit pattern of the wired signal and the wireless control signal.

2. The wireless transmitting device according to claim 1, characterized in that the wireless signal generating unit generates the wireless signal including the wireless control signal that is longer than the section in which no information transmission occurs between frames of the wired signal by overwriting the preamble included in the frame with the wireless control signal.

3. The wireless transmission device according to claim 1 or 2, characterized in that no error detection processing is performed even if the wired signal includes an error detection code.

4. A wireless transmission device as described in any one of claims 1 to 3, comprising: a plurality of wired receiving units corresponding to a plurality of signal systems, respectively; and a single wireless transmitting unit for transmitting the wireless signal, wherein the wireless signal generating unit multiplexes the plurality of signal systems to generate the wireless signal, and the single wireless transmitting unit multiplexes and transmits the plurality of signal systems.

5. The wireless transmitting device according to any one of claims 1 to 4, wherein the frames constituting the wired signal are Ethernet frames.

6. A wireless receiving device that receives the wireless signal transmitted by the wireless transmitting device according to any one of claims 1 to 5, comprising: a wireless control signal processing unit that performs wireless communication management in a wireless transmission section via the wireless signal based on the wireless control signal contained in the wireless signal.

7. The wireless receiving device according to claim 6, characterized in that the wireless control signal processing unit performs at least one of measuring the wireless communication quality in the wireless transmission section and controlling the operation of the receiving processing of the wireless signal transmitted by the wireless transmitting device as the wireless communication management.

8. The wireless receiving device according to claim 6, further comprising: a wired signal generating unit that removes the wireless control signal from the received wireless signal to restore the wired signal received by the wireless transmitting device; and a wired transmitting unit that transmits the restored wired signal via a wired connection.

9. The wireless receiving device according to claim 8, characterized in that, when a predetermined preamble cannot be detected in the frame portion for transmitting information of the received wireless signal, the wired signal generating unit restores the wired signal by re-adding the preamble.

10. A wireless relay device that relays the wireless signal transmitted by the wireless transmitting device according to any one of claims 1 to 5, comprising: a wireless retransmission signal generating unit that generates a wireless retransmission signal, which is a wireless signal to be retransmitted, based on the received wireless signal; and a wireless transmitting unit that transmits the wireless retransmission signal.

11. A wireless relay device as described in claim 10, further comprising a wireless control signal processing unit that generates a wireless control signal for the wireless retransmission signal by adding information about the number of relays to the wireless control signal contained in the received wireless signal, wherein the wireless retransmission signal generating unit generates the wireless retransmission signal including the wireless control signal generated by the wireless control signal processing unit.

12. A control circuit for controlling a wireless transmitting device that receives a wired signal composed of a plurality of frames and transmits the wired signal by converting it into a wireless signal, the control circuit causing the wireless transmitting device to execute a step of inserting a wireless control signal, which is a control signal for managing wireless communications, into a section in which no information is being transmitted between frames of the received wired signal.

13. A storage medium storing a program for controlling a wireless transmission device that receives a wired signal composed of a plurality of frames and transmits the wired signal by converting it into a wireless signal, the program causing the wireless transmission device to execute a step of inserting a wireless control signal, which is a control signal for wireless communication, into a section between frames of the received wired signal in which no information is being transmitted.

14. A communication system that makes part of wired communication wireless, comprising: a wireless transmitting device that receives a wired signal that is a signal transmitted by a wire and is composed of a plurality of frames, generates a wireless signal by inserting a wireless control signal, which is a control signal for wireless communication, into a section where information transmission between frames of the received wired signal is not taking place, and transmits the generated wireless signal; and a wireless receiving device that receives the wireless signal transmitted by the wireless transmitting device, performs wireless communication management in the wireless transmission section by the wireless signal based on the wireless control signal contained in the received wireless signal, removes the wireless control signal from the received wireless signal, restores the wired signal received by the wireless transmitting device, and transmits the restored wired signal via a wired connection.

15. A communication method for making part of wired communication wireless, comprising the steps of: a wireless transmitting device receiving a wired signal, the wired signal being a signal transmitted by a wire and consisting of a plurality of frames; a step of the wireless transmitting device generating a wireless signal by inserting a wireless control signal, which is a control signal for wireless communication, into a section where no information transmission is taking place between frames of the received wired signal; a step of the wireless transmitting device transmitting the generated wireless signal; a step of the wireless receiving device receiving the wireless signal; a step of the wireless receiving device performing wireless communication management in the wireless transmission section by the wireless signal based on the wireless control signal contained in the received wireless signal; a step of the wireless receiving device removing the wireless control signal from the received wireless signal to restore the wired signal received by the wireless transmitting device; and a step of the wireless receiving device transmitting the restored wired signal by wire.

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