JP2013046333A - Wireless communication device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication device and method that can prevent deterioration in a transfer rate (throughput) and an error rate of a signal compared with those before environment degradation, and that can prevent the device scale from being enlarged.SOLUTION: A transmission signal modulation device 1 and a transmission signal amplification device 2 are connected with each other by a coaxial cable 5. A transmission signal is transmitted from the transmission signal modulation device 1 to the transmission signal amplification device 2 via the coaxial cable 5. The transmission signal amplification device 2 receives the transmitted signal and measures a BER, and compares the measured BER with a threshold to determine deterioration of the coaxial cable 5. In the case that it is determined that the coaxial cable is deteriorated, the transmission signal modulation device is notified of the cable deterioration, and the transmission signal modulation device performs any one or both of control for reducing a frequency of the transmission signal and control for changing a modulation system of the transmission signal.

Description

  The present invention relates to a radio communication apparatus and method capable of maintaining the same signal throughput and error rate as when a cable transmitting a signal is deteriorated even when the cable is not deteriorated.

  In recent years, in communication services, the communication capacity has increased with the diversification of applications. This increase in communication capacity is realized by complicating the modulation system and shifting the frequency to be used to a high frequency. Further, if the communication line is disconnected as the communication capacity is increased, a great financial damage is caused. Therefore, it is required to avoid such communication line disconnection.

  On the other hand, in the wireless communication device, the communication state with the counterpart wireless communication device varies greatly depending on the installation location. For this reason, some wireless communication apparatuses can switch a plurality of modulation methods manually or automatically depending on the state of a received signal. For example, in quadrature amplitude modulation (QAM), 256QAM, 160QAM, etc. may be switched to quadrature phase-shift keying (QPSK).

  While there is a mechanism for avoiding disconnection of the radio itself, it is also necessary to improve the reliability of the device itself. In many cases, the base station device of such a wireless communication device is provided with a device in the vicinity of the antenna (generally called an out-door unit (ODU)) in addition to the base station main unit. In order to provide flexibility in arrangement, the connection is often made with a wired cable (coaxial cable or the like) having higher flexibility (bending tolerance) than a waveguide or the like. However, when using a wired cable, the cable is subject to a minute burden due to the maintenance of the device and the outdoor installation environment. It is difficult to avoid deterioration.

  If this cable deterioration occurs, the communication line will be disconnected. If the cable deterioration can be diagnosed in advance without disconnecting the wireless communication, the cable can be replaced before the cable is disconnected, and the line is maintained. Can continue. Since this cable is covered, it is difficult to understand the degree of cutting and deterioration from the outside, and it is necessary to judge the deterioration by a method other than a visual method.

  For example, Patent Literature 1 to Patent Literature 13 describe a method for determining the cable deterioration. A typical configuration of Patent Document 1 is shown in FIG. 5, and a typical configuration of Patent Document 5 is shown in FIG. The methods of Patent Document 1 to Patent Document 5 superimpose any monitoring signal or inspection signal on a normal transmission signal (hereinafter referred to as a main signal), and determine the cable deterioration by monitoring the characteristics of the monitoring signal or inspection signal. Technology.

  That is, in the method of Patent Document 1, one end of a cable is terminated, a high-frequency pulse is applied to the other end of the cable, and a time change of a reflected wave of an input pulse is observed to determine deterioration or disconnection of the cable. . In the method of Patent Document 2, the disconnection of the cable is determined by inputting the measurement signal and comparing the measurement signal with the measurement signal shifted in phase corresponding to the length of the cable.

  In the method of Patent Document 3, a disconnection is determined by extracting a feature at the time of disconnection from a response waveform of a signal. In the method of Patent Document 4, the resistance of the cable is evaluated by a high-frequency current, and the disconnection is detected by utilizing the skin effect that the high-frequency current flows on the conductor surface. Furthermore, in the method of Patent Document 5, a monitoring optical signal is superimposed in addition to an optical fiber transmission signal, and the attenuation rate is observed to determine cable deterioration. This example is an example of an optical cable, but it can be easily analogized to determine the deterioration of the coaxial cable by replacing the optical cable with a coaxial cable and checking the attenuation rate of the transmission signal.

  On the other hand, the methods of Patent Literature 6 to Patent Literature 10 are methods for detecting cable deterioration and disconnection by improving the cable. That is, in the methods of Patent Document 6 and Patent Document 7, a disconnection detection cable is provided in addition to the cable through which the main signal passes, and a connection failure such as a cable disconnection or a connector connecting the cable is determined.

  In the method of Patent Document 8, the disconnection of the power supply line is determined by comparing the voltage drops of the plurality of power supply lines. In the method of Patent Document 9, a disconnection detection cable is arranged around a cable through which a main signal passes. In the method of Patent Document 10, a cable is constituted by a plurality of strands, and disconnection is detected by a characteristic change caused by the breakage of the outermost strand.

  The methods of Patent Document 11 and Patent Document 12 are methods using a device that detects a physical change due to cable loss. That is, in the technique of Patent Document 11, an AC voltage is applied to a cable insulator, the charging current is measured to determine a loss current, and the level of the third harmonic component in the frequency component of the loss current is set to normal. The degree of insulation deterioration is determined by comparing with the value of the level of the cable. In the technique of Patent Document 12, a transmitter and a receiver are brought into contact with each other at two points on the diameter on the outer periphery of the cable by using a fixing jig, and the ultrasonic propagation time is measured. The degree of deterioration is determined by comparison.

  On the other hand, there is a technique disclosed in Patent Document 13 as means for performing communication in response to deterioration of the wireless communication environment. A representative view of Patent Document 13 is shown in FIG. The technique disclosed in Patent Document 13 is a technique for determining deterioration of a signal transmitted / received via an antenna based on the SNR, and changing the modulation method or coding rate of the transmission signal based on that to maintain the line.

JP 2007-121102 A JP 2007-064858 A JP 2008-292181 A Japanese Patent Laid-Open No. 02-095273 JP-A-60-177238 JP 2010-212133 A JP 2010-185724 A JP 2008-202974 A JP 2007-299608 A JP 2007-139488 A JP 05-264642 A JP 2002-131292 A JP 2009-152876 A

  As described above, it is necessary to detect in advance cable deterioration between devices of a wireless communication device. The methods of Patent Document 1 to Patent Document 5 check the deterioration or disconnection of a cable by confirming the reflection (return loss) of the monitoring signal or inspection signal superimposed on the main signal, the passage loss (loss), or similar characteristics. to decide. However, when the return loss or loss actually deteriorates, the main signal does not pass, and it is difficult to detect cable deterioration in advance only with this method.

  If the characteristics in the cable degradation state can be extracted as in the method of Patent Document 3, it is possible to detect in advance, but in reality, differences in characteristics for each cable, differences in the environment used, differences in the form and method of cable degradation. It is very difficult to acquire data on the deterioration state of the cable used from the above, and it is difficult to determine the deterioration itself.

  On the other hand, from the viewpoint that cable deterioration or disconnection occurs from the outside of the cable, a method of using a high-frequency signal for a monitoring signal or an inspection signal as described in Patent Document 4 is effective in principle. However, in this method, in order to determine cable deterioration in advance, cable deterioration must be determined in a situation where the main signal is not affected. That is, the frequency of the high frequency signal needs to be set to 5 to 10 times that of the main signal. As a result, although it is effective for signals whose frequency is lower than 1 GHz, when the main signal is several GHz or more, the necessary high-frequency signal becomes 10 GHz or more, and the passing characteristics of the cable used are not sufficient. However, problems such as a complicated configuration of a signal source and a determination circuit occur, and it is difficult to use this method.

  Furthermore, the methods of Patent Document 6 to Patent Document 10 are methods in which a plurality of cables are arranged, or the cables themselves are improved to detect disconnection in advance. These techniques are effective in the use of low frequencies and DC voltages, but are difficult to use in high frequency signals. That is, if a disconnection detection cable is arranged near the main signal cable as in Patent Documents 6, 7, and 9, the impedance of the cable through which the main signal passes becomes unstable, and signal transmission itself becomes difficult.

  Although the method using a plurality of cables as described in Patent Document 8 is effective, it is difficult to divide or synthesize a high-frequency signal, unlike a DC signal flowing through a power supply line. Even if the configuration is adopted, there is a problem that the circuit configuration becomes complicated. If the core wire of the coaxial cable is composed of a plurality of materials as in the method of Patent Document 10, since the main signal is a high-frequency signal, when the deterioration of the cable is detected due to the skin effect, the high-frequency signal is also greatly attenuated, There is a problem that communication is not possible at the time of detection.

  Furthermore, the methods of Patent Document 11 and Patent Document 12 are methods using a device that detects a physical change due to cable loss. In the method of Patent Document 11, since a circuit for generating an AC voltage for deterioration diagnosis must be provided, there is a problem that the mounting area for this circuit increases. The method of Patent Document 12 is not suitable because a device for transmitting and receiving ultrasonic waves needs to be mounted on a cable, and the antenna of the communication device needs to be installed in a place where external conditions such as a high place are severe.

  As described above, in the methods described in Patent Literature 1 to Patent Literature 12, although deterioration of the cable can be detected, since the main signal cannot be communicated simultaneously with the degradation of the cable, detection before the communication is impossible is performed. difficult.

  On the other hand, the technique of Patent Document 13 is a technique for changing the modulation scheme or coding rate and maintaining the line when the signal transmission environment deteriorates in the signal transmitted from the antenna. In this method, the line can be maintained, but there is a problem that the transfer rate of the signal becomes worse than before the environmental degradation by changing the modulation method.

  An object of the present invention is to provide a radio communication apparatus and method in which a signal transfer rate (throughput) and an error rate are not deteriorated as compared with those before environmental degradation, and the scale of the apparatus is not increased. It is in.

  The wireless communication device according to the present invention is a wireless communication device in which at least two devices are connected by a cable, and a transmission signal is transmitted from one transmitting device connected by the cable to the other receiving device via the cable. The receiving side device includes a measuring unit that measures the degree of signal degradation from the transmission signal transmitted from the transmitting side device, and the measured degree of signal degradation and a predetermined threshold value. A determination means for comparing the deterioration of the cable based on the comparison result, and a notification means for notifying the transmission side device of the deterioration of the cable when it is determined that the cable has deteriorated, The transmission-side apparatus lowers the frequency of the transmission signal in accordance with the cable deterioration notification from the reception-side apparatus, or changes the modulation method of the transmission signal, or Control means for square control and further comprising a.

  A cable deterioration diagnosis device according to the present invention is a cable deterioration diagnosis device that diagnoses deterioration of a cable connected between two devices, and one of the two devices is connected to the other device via the cable. Means for transmitting the signal, means for receiving the signal transmitted via the cable in the other device, measuring the degree of deterioration of the signal, and the degree of deterioration of the measured signal in advance And a means for comparing the set threshold value and determining the deterioration of the cable based on the comparison result.

  The wireless communication method according to the present invention is a wireless communication method in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable. In the communication method, the receiving side device measures the degree of signal degradation from the transmission signal transmitted from the transmitting side device, the measured degree of signal degradation and a predetermined threshold value, And determining the deterioration of the cable based on the comparison result, and notifying the transmission side device of the deterioration of the cable when it is determined that the cable has deteriorated, and Either the side device reduces the frequency of the transmission signal or changes the modulation method of the transmission signal in response to the cable deterioration notification from the reception side device. Or both steps of controlling the to comprising a.

  The cable result diagnosis method according to the present invention is a cable deterioration diagnosis method for diagnosing deterioration of a cable connected between two devices, in which the transmission means transmits one device from the other device to the other device. A step of transmitting a signal to the device via the cable, a step of measuring means receiving a signal transmitted via the cable at the other device, and measuring a degree of deterioration of the signal, and a determination And means for comparing the measured degree of deterioration of the signal with a preset threshold value and determining the deterioration of the cable based on the comparison result.

  The program according to the present invention is a wireless communication device in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable. As a program for causing a computer to function as a measurement means for measuring the degree of deterioration of a signal from a transmission signal transmitted from the transmission side device, and the degree of deterioration of the measured signal in advance. A determination means for comparing the determined threshold value and determining the deterioration of the cable based on the comparison result; and a notification for notifying the transmission side device of the deterioration of the cable when it is determined that the cable has deteriorated The transmission signal modulation method is changed in accordance with the cable degradation notification from the receiving device and the reception side device. Of that, characterized in that to the control means for one or both control, to function.

  The program according to the present invention is a program for causing a computer to function as a cable deterioration diagnosis device that diagnoses deterioration of a cable connected between two devices, and the computer is one of the two devices. Means for transmitting a signal from the device to the other device via the cable, means for receiving a signal transmitted via the cable by the device on the other side, and measuring the degree of deterioration of the signal; The degree of degradation of the measured signal is compared with a preset threshold value, and the device functions as a means for judging the degradation of the cable based on the comparison result.

  According to the present invention, the signal transfer rate and the error rate are not deteriorated as compared with those before environmental degradation, and the scale of the apparatus is not increased.

It is a block diagram which shows one Embodiment of the cable degradation diagnostic apparatus which concerns on this invention. It is a block diagram which shows the block diagram of FIG. 1 in detail. It is a block diagram which shows the normal radio | wireless transmitter which does not have a cable degradation diagnostic function. It is a figure which shows an example of the signal which passes a coaxial cable. 10 is a representative diagram of Patent Document 1. FIG. 10 is a representative diagram of Patent Document 2. FIG. It is a typical figure of patent document 13.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. First, an outline of the present embodiment will be described with reference to FIG. FIG. 1 shows an example of a wireless communication device in which two devices are connected by a coaxial cable. In the figure, 1 is a device for generating a transmission signal by modulating a baseband signal (hereinafter referred to as a transmission signal modulation device), 2 is amplifying the transmission signal, and then frequency-converting it to a specified frequency. This is a device 2 that converts the signal and supplies it to the antenna (hereinafter referred to as a transmission signal amplification device) 2, and the transmission signal modulation device 1 and the transmission signal amplification device 2 are connected by a coaxial cable 5.

  An example in which the transmission signal modulation device 1 and the transmission signal amplification device 2 are housed in separate housings, and the separate housings are installed at separate locations, and the deterioration diagnosis of the coaxial cable 5 is performed in this wireless communication device. Will be explained.

  For example, the transmission signal modulation device 1 is installed indoors or the like, and the transmission signal amplification device 2 is installed near the outdoor antenna 8, and a coaxial cable 5 is connected therebetween. A transmission signal, a control signal, and a power signal for operating the transmission signal amplifying device 2 are both transmitted and supplied from the transmission signal modulation device 1 to the transmission signal amplifying device 2 in the coaxial cable 5. In addition, the reception signal received by the antenna 8 is transmitted from the transmission signal amplification device 2 to the transmission signal modulation device 1 using different frequencies. The transmission signal modulation apparatus 1 changes the intensity and modulation method of the transmission signal based on the intensity of the received signal.

  In this embodiment, the reference for changing the modulation method of the transmission signal in the transmission signal modulation device 1 is the state of the transmission signal after passing through the coaxial cable 5 connecting the devices in addition to other criteria (received signal etc.) Also included. Specifically, the transmission signal amplifier 2 branches the transmission signal, the transmission signal control instruction circuit 7 measures the BER (error rate), and when the measured BER exceeds a preset threshold value, A transmission signal control instruction signal 9 is transmitted to the transmission signal modulation device 1 in order to change the modulation method of the main signal. Instead of the instruction signal 9, a deterioration notification indicating that the coaxial cable has deteriorated may be transmitted. In the present embodiment, for example, BER (error rate) is used as the degree of signal degradation. Instead of the instruction signal 9, a deterioration notification indicating that the coaxial cable has deteriorated may be transmitted.

  When the transmission signal modulation apparatus 1 receives the transmission signal control instruction signal 9 from the transmission signal amplification apparatus 2, the transmission signal modulation apparatus 1 simultaneously performs one or both of lowering the frequency of the main signal and changing the modulation method. Also warn the user of cable degradation. The user can replace the coaxial cable 5 by a cable deterioration warning.

  At this time, the modulation method is determined step by step as the modulation method of the main signal, and when the measured BER exceeds the threshold value, the current modulation method is changed to the next-stage modulation method. This will be described later with a specific example.

  Further, in order to suppress a decrease in the throughput of the transmission signal due to the modulation method change, in the signal transmission of the coaxial cable 5, the transmission data amount is reduced by distributing and transmitting the frequency of the transmission signal using a plurality of bands. Thus, after passing through the coaxial cable 5, the original reference frequency and modulation method are restored, and the antenna 8 transmits the stable wireless communication until the coaxial cable 5 is replaced.

  Next, embodiments of the present invention will be described in more detail. In the present embodiment, the transmission signal modulation device 1 and the transmission signal amplification device 2 are connected by a coaxial cable 5 as shown in FIG. The transmission signal modulation device 1 is a device that converts transmission data into a modulation signal, and the transmission signal amplification device 2 is a device that amplifies the modulation signal and converts it to a prescribed frequency by frequency conversion. The transmission signal modulation device 1 includes a transmission interface unit 3 and a control unit 6 for inputting and outputting signals.

  The transmission signal amplification device 2 includes an amplification interface unit 4 and a transmission signal control instruction circuit 7. The amplification interface unit 4 that performs signal input / output of the transmission signal amplifier 2 measures the BER and outputs it to the transmission signal control instruction circuit 7. The transmission signal control instruction circuit 7 controls the modulation method and the like based on the BER measurement result. The amplified signal output terminal of the transmission signal amplifying device 2 is connected to the antenna 8.

  When changing the modulation method or frequency of the signal of the coaxial cable 5, the transmission signal control instruction circuit 7 and the amplification interface unit 4 are connected to transmit the transmission signal control instruction signal 9 to the control unit 6. A transmission signal control instruction signal 9 is transmitted from the transmission signal amplifier 2 through the coaxial cable 5 to the transmission signal modulator 1. The transmission signal control instruction signal 9 is transmitted to the control unit 6 via the transmission interface unit 3.

  FIG. 2 is a block diagram showing FIG. 1 in more detail. The transmission interface unit 3 mounted on the transmission signal modulation device 1 includes a baseband signal unit 11 and a modulation unit 12. The baseband signal unit 11 generates a baseband signal from the transmission data. The modulation unit 12 modulates and converts the baseband signal to an intermediate frequency (IF) or a transmission frequency (RF), and also converts the frequency of the transmission signal to a plurality of bands when converting the baseband signal to RF when the cable is deteriorated. Use distributed transmission. The baseband signal unit 11 and the modulation unit 12 are connected to the control unit 6 for controlling each block by a signal line.

  The amplification interface unit 4 mounted on the transmission signal amplifying device 2 performs a demodulation unit 13 that demodulates the transmission signal, performs one or both of amplification and frequency conversion of the transmission signal, and also transmits to the modulation unit 12 when the cable deteriorates. A main circuit unit 10 is provided for returning the frequency-divided (frequency-lowered) signal to the original RF and modulation method.

  The transmission signal control instruction circuit 7 compares the BER measurement unit 14 that measures the BER from the signal transmitted from the demodulation unit 13 with a threshold value that determines the measured BER value and the modulation method (or frequency) of the main signal. A determination unit 15 and a modulation scheme transmission frequency change instruction unit 16 that transmits a signal for controlling the transmission frequency and modulation scheme of the transmission signal based on the determination result are provided.

  The demodulation unit 13 and the main circuit unit 10 are connected to the transmission interface unit 3 mounted on the transmission signal modulation device 1 via the coaxial cable 5. The main circuit unit 10 is connected to the antenna 8. The BER measurement unit 14 is connected to the demodulation unit 13 in order to receive the demodulated main signal. The determination unit 15 is connected to the BER measurement unit 14 through a signal line in order to compare the BER measurement result with a threshold value for changing the modulation method and the like.

  Further, the determination unit 15 is connected to the modulation scheme transmission frequency change instruction unit 16. The modulation scheme transmission frequency change instruction section 16 is connected to the amplification interface section 4 via a signal line in order to transmit an instruction to change the transmission frequency or modulation scheme of the main signal based on the determination result to the control section 6 of the transmission signal modulation apparatus 1. Has been.

  Next, the operation of the present embodiment will be described. First, the operation of a normal wireless transmission apparatus having no cable deterioration diagnosis function will be described with reference to FIG. In FIG. 3, the same parts as those in FIG. The transmission interface unit 3 of the transmission signal modulation device 1 includes a baseband signal unit 11 and a modulation unit 12, and each block is controlled by a control unit 6 connected by a signal line. When transmitting a transmission signal, the baseband signal unit 11 generates a baseband signal and transmits it to the modulation unit 12. The modulation unit 12 modulates the baseband signal and the control signal, and transmits the modulated signal to the amplification interface unit 4 mounted on the transmission signal amplifying device 2 via the coaxial cable 5.

  Next, the operation of the wireless communication apparatus having the cable deterioration determination function of this embodiment will be described with reference to FIG. On the side of the transmission signal modulation device 1, a transmission interface unit 3 and a control unit 6 having a normal configuration are provided, and the main signal of this device is transmitted from the transmission interface unit 3 to the transmission signal amplification device 2.

  The main signal received by the amplification interface 4 of the transmission signal amplifying apparatus 2 is branched into a signal transmitted to the main circuit unit 10 and a signal transmitted to the demodulation unit 13. The main signal demodulated by the demodulating unit 13 is sent to the BER measuring unit 14 in the transmission signal control instruction circuit 7. The BER measurement unit 14 measures the BER from the demodulated main signal and outputs the measurement result to the determination unit 15. The determination unit 15 compares the measured BER with a preset BER threshold value and transmits the comparison result to the modulation scheme transmission frequency change instruction unit 16.

  In the present embodiment, the communication environment of the main signal is determined based on the determination result, and the transmission frequency of the main signal is changed by lowering the frequency of the transmission signal based on the determination result or selecting a modulation method suitable for the environment. Either (or lower) or change the modulation method, one or both are controlled. When it is necessary to change the transmission frequency and the modulation method by comparison with the threshold value, the transmission signal control instruction signal 9 is transmitted from the modulation method transmission frequency change instruction unit 16 to the control unit 6 on the transmission signal modulation device 1 side.

  The transmission signal control instruction signal 9 is transmitted to the control unit 6 via the amplification interface unit 4, the coaxial cable 5, and the transmission interface unit 3 on the transmission signal modulation device 1 side. When an instruction signal for changing the modulation method or the like is transmitted from the transmission signal control instruction signal 9, a cable deterioration warning is issued, and the transmission signal between the modulation circuit 12 and the main circuit section 10 via the coaxial cable 5 is output. Control is performed so that the modulation method is changed to a modulation method with relaxed conditions. The same applies to the case where it is instructed to lower the frequency of the main signal as described above. A method for changing the modulation method will be described later.

  FIG. 4 shows an example of a signal passing through the coaxial cable. As shown in FIG. 4A, in transmission at a normally used frequency, the transmission signal throughput decreases due to the modulation method change. In FIG. 4A, the transmission center frequency is f0. In the present embodiment, in order to suppress a decrease in throughput, the frequency of the transmission signal is transmitted using a plurality of bands in transmission between the coaxial cables 5 as shown in FIG. 4B.

  That is, as shown in FIG. 4B, data is distributed and transmitted in a plurality of frequency bands lower than the transmission center frequency f0 at available frequencies. The transmission center frequency f0 'is assumed to be (f0'≤f0). By doing so, it is possible to prevent a decrease in the amount of transfer data, and as shown in FIG. 4C, the main circuit unit 12 returns the original reference frequency and modulation method to stable wireless communication until cable replacement. Communication can be maintained.

  As a method of changing to a modulation method that is gradually relaxed by the transmission signal control instruction signal 9, for example, by reducing the number of bits in a symbol such as 256QAM → 128QAM → 64QAM → 32QAM → 16QAM → QPSK, There is a method for reducing signal points in a diagram (Constellation Diaglam).

  For example, when the current modulation method is 256QAM and the transmission signal control instruction signal 9 is transmitted, the next modulation method is changed to 128QAM. Even if the modulation method is changed to 128 QAM, if the measured BER exceeds a preset BER threshold, it may be changed to 64 QAM in the next stage.

  Similarly, if the BER exceeds the threshold even if the modulation method is changed to 64QAM, it is desirable to change the modulation method to a modulation method whose conditions are relaxed step by step, such as changing to the next 32QAM. . As a result, even if an error of the same level occurs in the deteriorated coaxial cable 5, the error rate is reduced and communication can be continued.

  In addition, it is possible to prevent a decrease in throughput caused by changing the modulation method by dispersing the frequency of the transmission signal using a plurality of bands. Furthermore, by reducing the frequency, the signal passing through the cable propagates using a deep region from the surface due to the skin effect. As a result, it is possible to reduce the influence of deterioration caused from the cable surface. Therefore, in the signal before the frequency is lowered, an error occurs and communication is impossible, but communication is possible by lowering the frequency.

  As described above, the transmission signal modulation apparatus 2 may be notified that the coaxial cable has deteriorated instead of the transmission signal control instruction signal 9, and the transmission signal modulation apparatus 2 notifies the cable deterioration from the transmission signal amplification apparatus 1. One or both of the control may be performed in such a manner that the frequency of the transmission signal is lowered according to the above and the modulation method of the transmission signal is changed.

  Moreover, although the example which used one coaxial cable was shown in the above embodiment, a transmission signal is returned to the transmission signal modulation apparatus 1 from the transmission signal amplification apparatus 2 using another coaxial cable, for example, and transmission signal modulation is performed. The same effect can be obtained even in a configuration in which the BER is confirmed in the apparatus 1 and similarly controlled by the control unit 6.

  Furthermore, although the BER of the transmission signal is measured as the degree of deterioration of the transmission signal, the present invention is not limited to this, and for example, the number of errors in the transmission signal may be measured. Further, MER, SER, or the like may be used as the degree of deterioration of the transmission signal. Moreover, although the example which diagnoses deterioration of a coaxial cable was shown, this invention is not restricted to this, For example, it can be used also for deterioration diagnosis, such as a USB cable and a twisted pair cable.

  As described above, according to the present embodiment, for example, there is a gap between a device that modulates a baseband signal and generates a transmission signal, and a device that amplifies the transmission signal, converts it to a specified frequency, and supplies it to the antenna. In a wireless communication apparatus connected by a coaxial cable, BER is measured from a transmission signal that has passed through the coaxial cable, and deterioration of the coaxial cable is determined based on a comparison result between the measurement result and a predetermined threshold value. The communication line can be maintained by changing either one or both of the transmission frequency and / or modulation method of the main signal passing through the coaxial cable based on the measurement result.

  As a result, the coaxial cable can be exchanged before the coaxial cable is completely cut off, and the transmission signal that passes through the coaxial cable until the coaxial cable is exchanged is transmitted by a frequency or modulation method that matches the state of the coaxial cable. It is possible to maintain the line state before it is determined. In this embodiment, since deterioration is determined based on the main signal, it is not necessary to construct a large-scale circuit, and an apparatus for diagnosing cable deterioration is not particularly required. In other words, there is no need to provide a separate mechanical device, only a function for measuring the BER from the main signal and the frequency and modulation method of the main signal are changed from the BER measurement result. This is effective because there is no need for human operation.

  Note that the wireless communication device and the cable deterioration diagnosis device can be realized by hardware, software, or a combination thereof. Realized by software means realized by a computer reading and executing a program.

  The program may be stored using various types of non-transitory computer readable media and supplied to the computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD- R, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)).

  The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  In addition, although a part or all of the said embodiment can be described also as the following additional remarks, it is not restricted to the following.

(Appendix 1) A wireless communication device in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable,
The receiving side device
Measuring means for measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
A determination means for comparing the degree of deterioration of the measured signal with a predetermined threshold, and determining the deterioration of the cable based on the comparison result;
When it is determined that the cable has deteriorated, the notification device notifies the transmission side device of the deterioration of the cable,
Control means for controlling either or both of the transmission side device to lower the frequency of the transmission signal in accordance with the cable deterioration notification from the reception side device and to change the modulation method of the transmission signal ,
A wireless communication apparatus comprising:

  (Supplementary Note 2) When the cable degradation is notified from the reception side device, the transmission side device distributes the data passing through the cable to a plurality of frequency bands and simultaneously transmits the data to the reception side device. The wireless communication device according to appendix 1, wherein the wireless communication device transmits the wireless communication device.

    (Supplementary Note 3) When the receiving side apparatus determines that the cable has deteriorated and the frequency, modulation method, or both in transmission of transmission signals between the transmitting side apparatus and the receiving side apparatus are changed. The wireless communication device according to appendix 1, wherein the signal after passing through the cable is returned to the changed frequency and / or modulation method and output from the antenna.

  (Supplementary Note 4) Instead of measuring the degree of deterioration of the transmission signal at the reception side apparatus, the transmission signal is returned from the reception side apparatus to the transmission side apparatus via a cable different from the cable, and the transmission is performed. If the side device measures the degree of deterioration of the transmission signal and determines that the cable has deteriorated, either the frequency of the transmission signal is lowered, or the modulation method of the transmission signal is changed, or The wireless communication apparatus according to any one of appendices 1 to 3, wherein both of the controls are performed.

(Appendix 5) A cable deterioration diagnosis device for diagnosing deterioration of a cable connected between two devices,
Means for transmitting a signal from one of the two devices to the other device via the cable;
Means for receiving a signal transmitted via the cable at the other device and measuring the degree of deterioration of the signal;
Means for comparing the degree of degradation of the measured signal with a preset threshold, and determining degradation of the cable based on the comparison result;
A cable deterioration diagnosis device comprising:

(Appendix 6) A wireless communication method in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable,
The receiving device is
Measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
Comparing the measured degree of degradation of the signal with a predetermined threshold, and determining degradation of the cable based on the comparison result;
If it is determined that the cable has deteriorated, the step of notifying the transmission side device of the deterioration of the cable,
The transmitting device is
A step of reducing either the frequency of the transmission signal or changing the modulation method of the transmission signal in response to the cable degradation notification from the reception side device,
A wireless communication method comprising:

  (Supplementary note 7) When the transmission side device is notified of the cable deterioration from the reception side device, the signal passing through the cable is distributed to a plurality of frequency bands and data is simultaneously transmitted to the reception side device. The wireless communication method according to appendix 6, wherein transmission is performed.

    (Supplementary Note 8) When the receiving side device determines that the cable has deteriorated and the frequency, modulation method, or both in transmission of the transmission signal between the transmitting side device and the receiving side device are changed 7. The wireless communication method according to appendix 6, wherein the signal after passing through the cable is returned to the changed frequency and / or modulation method and output from the antenna.

  (Supplementary Note 9) Instead of measuring the degree of deterioration of the transmission signal at the reception side device, the transmission signal is returned from the reception side device to the transmission side device via a cable different from the cable, and the transmission is performed. If the side device measures the degree of deterioration of the transmission signal and determines that the cable has deteriorated, either the frequency of the transmission signal is lowered, or the modulation method of the transmission signal is changed, or The wireless communication method according to any one of appendices 6 to 8, wherein both controls are performed.

(Appendix 10) At least two devices are connected by a cable, and the computer is caused to function as a wireless communication device that transmits a transmission signal from one transmitting device connected by the cable to the other receiving device via the cable. A program for
The computer,
Measuring means for measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
A determination means for comparing the degree of deterioration of the measured signal with a predetermined threshold, and determining the deterioration of the cable based on the comparison result;
If it is determined that the cable has deteriorated, a notification means for notifying the transmission side device of the deterioration of the cable;
Control means for controlling either one or both of lowering the frequency of the transmission signal in response to the cable deterioration notification from the receiving side device and changing the modulation method of the transmission signal;
Program to make it function.

  (Additional remark 11) Furthermore, when the cable degradation is notified from the reception side device, as a means for distributing the data passing through the cable to a plurality of frequency bands and transmitting data to the reception side device at the same time The program according to appendix 10, wherein the program is made to function.

    (Supplementary note 12) Further, when it is determined that the cable has deteriorated and the frequency, modulation method, or both in transmission signal transmission between the transmission side device and the reception side device are changed, the cable 12. The program according to appendix 10, wherein the signal after passing through is made to function as means for returning to the changed frequency and / or modulation method and outputting from the antenna.

  (Supplementary note 13) Further, instead of measuring the degree of deterioration of the transmission signal at the reception side device, the transmission signal is returned from the reception side device to the transmission side device via a cable different from the cable, When the transmission side device measures the degree of deterioration of the transmission signal and determines that the cable has deteriorated, either the frequency of the transmission signal is lowered, or the modulation method of the transmission signal is changed. The program according to any one of appendices 10 to 12, wherein the program is caused to function as a means for performing one or both of the controls.

(Supplementary note 14) A program for causing a computer to function as a cable deterioration diagnosis device for diagnosing deterioration of a cable connected between two devices,
The computer,
Means for transmitting a signal from one of the two devices to the other device via the cable;
Means for receiving a signal transmitted via the cable at the other device and measuring the degree of deterioration of the signal;
Means for comparing the degree of degradation of the measured signal with a preset threshold, and determining degradation of the cable based on the comparison result;
Program to make it function.

  In particular, the present invention can be suitably used for deterioration diagnosis of a coaxial cable of a wireless communication apparatus in which two devices divided into separate housings are connected by a coaxial cable.

DESCRIPTION OF SYMBOLS 1 Transmission signal modulation apparatus 2 Transmission signal amplification apparatus 3 Transmission interface part 4 Amplification interface part 5 Coaxial cable 6 Control part 7 Transmission signal control instruction circuit 8 Antenna 9 Transmission signal control instruction signal 10 Main circuit part 11 Baseband signal part 12 Modulation unit 13 Demodulation unit 14 BER measurement unit 15 Determination unit 16 Modulation system transmission frequency change instruction unit

Claims (9)

A wireless communication device in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable;
The receiving side device
Measuring means for measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
A determination means for comparing the degree of deterioration of the measured signal with a predetermined threshold, and determining the deterioration of the cable based on the comparison result;
When it is determined that the cable has deteriorated, the notification device notifies the transmission side device of the deterioration of the cable,
Control means for controlling either or both of the transmission side device to lower the frequency of the transmission signal in accordance with the cable deterioration notification from the reception side device and to change the modulation method of the transmission signal ,
A wireless communication apparatus comprising:   When the cable degradation is notified from the reception side device, the transmission side device distributes the data passing through the cable to a plurality of frequency bands and transmits data to the reception side device at the same time. The wireless communication apparatus according to claim 1, wherein:   When the receiving side apparatus determines that the cable has deteriorated and the frequency, modulation method, or both in transmission of transmission signals between the transmitting side apparatus and the receiving side apparatus are changed, the cable 2. The radio communication apparatus according to claim 1, wherein the signal after passing through is returned to the changed frequency and / or modulation method and output from the antenna.   Instead of measuring the degree of deterioration of the transmission signal at the reception side device, the transmission side device returns the transmission signal to the transmission side device via a cable different from the cable, and the transmission side device returns the transmission signal to the transmission side device. When the degree of deterioration of the transmission signal is measured and it is determined that the cable has deteriorated, either one or both of the control of lowering the frequency of the transmission signal and changing the modulation method of the transmission signal are performed. The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus performs the wireless communication apparatus. A cable deterioration diagnosis device for diagnosing deterioration of a cable connected between two devices,
Means for transmitting a signal from one of the two devices to the other device via the cable;
Means for receiving a signal transmitted via the cable at the other device and measuring the degree of deterioration of the signal;
Means for comparing the degree of degradation of the measured signal with a preset threshold, and determining degradation of the cable based on the comparison result;
A cable deterioration diagnosis device comprising: A wireless communication method in which at least two devices are connected by a cable, and a transmission signal is transmitted from the one transmission-side device connected by the cable to the other reception-side device via the cable,
The receiving device is
Measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
Comparing the measured degree of degradation of the signal with a predetermined threshold, and determining degradation of the cable based on the comparison result;
If it is determined that the cable has deteriorated, the step of notifying the transmission side device of the deterioration of the cable,
The transmitting device is
A step of reducing either the frequency of the transmission signal or changing the modulation method of the transmission signal in response to the cable degradation notification from the reception side device,
A wireless communication method comprising: A cable deterioration diagnosis method for diagnosing deterioration of a cable connected between two devices,
Transmitting means for transmitting a signal from one of the two devices to the other device via the cable;
Measuring means for receiving a signal transmitted via the cable in the device on the other side, and measuring the degree of deterioration of the signal;
A determination means comparing the degree of degradation of the measured signal with a preset threshold, and determining degradation of the cable based on the comparison result;
A cable deterioration diagnosis method comprising: A program for causing a computer to function as a wireless communication device that transmits at least two devices via a cable from one transmitting device connected by the cable to the other receiving device. There,
The computer,
Measuring means for measuring the degree of signal degradation from the transmission signal transmitted from the transmission side device;
A determination means for comparing the degree of deterioration of the measured signal with a predetermined threshold, and determining the deterioration of the cable based on the comparison result;
If it is determined that the cable has deteriorated, a notification means for notifying the transmission side device of the deterioration of the cable;
Control means for controlling either one or both of lowering the frequency of the transmission signal in response to the cable deterioration notification from the receiving side device and changing the modulation method of the transmission signal;
Program to make it function. A program for causing a computer to function as a cable deterioration diagnosis device for diagnosing deterioration of a cable connected between two devices,
The computer,
Means for transmitting a signal from one of the two devices to the other device via the cable;
Means for receiving a signal transmitted via the cable at the other device and measuring the degree of deterioration of the signal;
Means for comparing the degree of degradation of the measured signal with a preset threshold, and determining degradation of the cable based on the comparison result;
Program to make it function.

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