JP2006050306A - Communication apparatus and communication system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication apparatus capable of reducing a lowering in communication speed as much as possible while maintaining the reliability of communication even when a communicating state with respect to communication data is unstable, and to provide a communication system using the communication apparatus. <P>SOLUTION: Code set control units 9 and 10 control a code setting part 8 so as to change and set an error correcting code set by the code setting part 8 in accordance with the degree of error detected by a decoding part; thereby, error of communication data RD can be corrected without increasing error correcting capability of the error correcting code excessively. Thus, even when the communicating state of the communication data RD is unstable by impedance loss and noise from the electrical equipment connected to a power line in power line carrier communication, for example, the reliability of communication is maintained and a decrease in communication speed can be reduced as much as possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication device and a communication system using the communication device that transmits / receives communication data and performs error correction of communication data based on an error correction code, particularly when the communication state of communication data is not stable. However, the present invention relates to a communication apparatus and a communication system using the same, which can reduce the decrease in communication speed as much as possible while maintaining communication reliability.

2. Description of the Related Art In recent years, communication speeds have been increased with the spread of broadband using communication methods such as wireless LAN (Local Area Network) and ADSL (Asymmetric Digital Subscriber Line). In addition to these communication methods, power line carrier communication that can use a power line as a network transmission path has been proposed (for example, Patent Document 1). In a communication apparatus using such a communication method, an error correction code such as a convolutional code or a Reed-Solomon code is employed as an error correction of communication data in order to increase communication speed and improve communication reliability. Yes.
JP 2000-165304 A

  However, when the communication speed is increased, there is a disadvantage that communication data errors increase and communication reliability decreases. In this case, there is a method of increasing the error correction capability of the error correction code as much as possible. However, if the communication state is not stable due to increase / decrease in errors, simply increasing the error correction capability of the error correction code will Since the error correction capability becomes excessive when recovered, there is a disadvantage that the communication speed is unnecessarily lowered. For example, in power line carrier communication, the communication state may become unstable due to impedance loss or noise from the electrical equipment connected to the power line, so the communication reliability is maintained even in such a communication state. However, there has been a demand for a communication device that can reduce the decrease in communication speed as much as possible.

  The problem to be solved is that, when the communication state of communication data is not stable, if an error correction code having a high error correction capability is employed, the communication speed is reduced more than necessary.

  The main feature of the present invention is that the code setting control unit controls the code setting unit so as to change and set the set error correction code in accordance with the degree of error detected by the decoding unit. .

  In the communication apparatus of the present invention, the error correction code is changed and set according to the degree of error in the communication data, so that the error correction of the communication data can be performed without excessively increasing the error correction capability of the error correction code. I can do it. As a result, even when the number of errors changes and the communication state is not stable, the communication speed can be reduced as much as possible while maintaining the reliability of communication.

A first invention made to solve the above-described problems is a communication apparatus (1) that transmits and receives communication data (SD, RD) and performs error correction of communication data (SD, RD) based on an error correction code.
Because
A code setting unit (8, 57, 67) for setting an error correction code;
An encoding unit (51) for adding redundant bits based on the error correction code set by the code setting unit (8, 57, 67) to the communication data (SD);
A transmission unit (5) for transmitting communication data (SD) to which redundant bits are added by the encoding unit (51);
A receiving unit (6) for receiving transmitted communication data (RD);
Based on the error correction code set by the code setting unit (8, 57, 67), the decoding of the communication data (RD) received by the receiving unit (6) is detected and the detected error is corrected. And (65)
In accordance with the degree of error (for example, the number of errors) detected by the decoding unit (65), the code setting unit (8, 57, 67) is configured to change and set the error correction code set by the code setting unit (8, 57, 67). And a code setting control unit (9, 10) for controlling (8, 57, 67).

  With this configuration, the error correction code is changed and set according to the degree of error in the communication data, so that error correction of the communication data can be performed without excessively increasing the error correction capability of the error correction code. As a result, even when the number of errors changes and the communication state is not stable, the communication speed can be reduced as much as possible while maintaining the reliability of communication.

  The second invention made to solve the above problem is that the code setting control unit (9, 10) is configured such that the data length of redundant bits based on the error correction code set by the code setting unit (8, 57, 67). The code setting unit (8, 57, 67) is controlled so as to change the setting.

  With this configuration, since the data length of redundant bits based on the error correction code is changed and set, fine error correction can be performed. As a result, error correction can be performed efficiently, waste of error correction capability is reduced, and a reduction in communication speed can be further reduced.

  According to a third aspect of the present invention for solving the above-described problems, the code setting control units (9, 10) change the error correction code set by the code setting unit (8, 57, 67) to a different type ( For example, the code setting unit (8, 57, 67) is controlled so as to change and set the Reed-Solomon code to a turbo code.

  With this configuration, the error correction code method is changed to a different method (for example, Reed-Solomon code is changed to turbo code), so that the type of error that occurs (for example, random error, burst error, byte error) changes Even so, it is possible to select an error correction code system suitable for the type of error, and to further improve the reliability of communication.

4th invention made | formed in order to solve the said subject, a transmission part (5) transmits the communication data (SD) to which the redundant bit was added via a power line (2),
The receiving unit (6) receives the transmitted communication data (RD) through the power line (2).

  With this configuration, even if the communication state is not stable due to impedance loss or noise of electrical equipment connected to the power line, the error correction code is changed and set according to the degree of communication data error. While maintaining the reliability of the carrier communication, the communication speed can be reduced as much as possible.

According to a fifth aspect of the present invention made to solve the above-described problem, the transmission unit (5) performs wavelet inverse transform on the communication data (SD) to which redundant bits are added by the encoding unit (51) and transmits the communication data (SD). A conversion unit (52);
The reception unit (6) includes a wavelet conversion unit (64) that receives wavelet conversion of received communication data (RD).

  With this configuration, the communication apparatus transmits and receives communication data using wavelet transform, so that it is not necessary to perform complex operations performed by Fourier transform, and the circuit scale of the communication apparatus can be reduced.

A sixth aspect of the invention made to solve the above problems includes a communication state monitoring unit (9) that monitors a communication state (for example, SN ratio) of communication data (RD) received by the receiving unit (6),
A communication state output unit (9) that outputs a communication state of communication data (RD) monitored by the communication state monitoring unit (9) to a predetermined user interface (for example, 11).

  With this configuration, the communication state for the communication data is output to a predetermined user interface (for example, a display or a speaker), so that the user of the communication device can know the communication state for the communication data. Thereby, for example, when the error correction capability is not sufficient with respect to the communication state, the user can maintain communication by changing the communication outlet or using a noise-compatible device.

7th invention made | formed in order to solve the said subject is a communication system (100) which has the communication apparatus (1) and server (103) connected to the network (101),
The communication apparatus (1) further includes a communication state notification unit (9) for notifying the server (103) of a communication state of communication data (RD) monitored by the communication state monitoring unit (9). To do.

  With this configuration, since the server receives a communication state about communication data from the communication device, for example, when the error correction capability is not sufficient for the communication state, the server administrator cooperates with the service management company, Services that provide communication outlet changes and noise-compatible devices can be provided, and communication can be maintained.

An eighth invention made to solve the above problems is a receiving device (1) that receives communication data (SD, RD) and performs error correction of the communication data (SD, RD) based on an error correction code. There,
A code setting unit (8, 67) for setting an error correction code;
A receiving unit (6) for receiving transmitted communication data (RD);
Decoding for detecting an error in the communication data (RD) received by the receiving unit (6) and correcting the detected error based on the error correcting code set by the code setting unit (8, 67) Part (65),
The code setting unit (8, 67) is configured to change and set the error correction code set by the code setting unit (8, 67) according to the degree of error (for example, the number of errors) detected by the decoding unit (65). 67) and a code setting control unit (9, 10) for controlling.

  With this configuration, it is possible to provide a receiving apparatus that can reduce communication speed reduction as much as possible while maintaining communication reliability even when the communication state is unstable.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment 1)
FIG. 1 is a block diagram illustrating a communication apparatus according to the first embodiment. A communication apparatus to which the present invention is applied is, for example, a PLC (Power Line Communication) adapter 1 as indicated by a broken line in FIG. The PLC adapter 1 relays the power line 2 and the home appliance 3. In addition to the home appliance 3, a plurality of home appliances (not shown) are connected to the power line 2 via PLC adapters (not shown). That is, these home appliances connected to the PLC adapter constitute a home communication network by power line carrier communication via the power line 2.

  The PLC adapter 1 includes a transmission unit 5, a reception unit 6, a power line coupling unit 7, a control unit 8, a controller 9, and a setting information unit 10. The transmission unit 5 includes an error correction modulator 51, a wavelet inverse converter 52, a D / A converter 53, a transmission amplifier 54, and a band pass filter 55, as shown in the upper broken line frame in the figure. Yes. The receiving unit 6 includes a band-pass filter 61, an amplification degree controller 62, an A / D converter 63, a wavelet transformer 64, and an error correction demodulator 65, as shown in the broken line frame at the bottom of the figure. Yes.

  FIG. 2 is a block diagram showing the error correction modulator 51 of the transmission unit 5 in the first embodiment. The error correction modulator 51 includes a transmission selector 57 and an RS (Reed-Solomon) modulator, as shown in a broken-line frame in the figure. The RS modulator includes a first RS modulator 58 and a second RS modulation. A container 59.

  FIG. 3 is a block diagram showing the error correction demodulator 65 of the receiving unit 6 in the first embodiment. The error correction demodulator 65 includes a reception selector 67 and an RS (Reed-Solomon) demodulator, as shown in a broken line frame in the figure. The RS demodulator includes a first RS demodulator 68 and a second RS demodulator. Instrument 69.

  In the above configuration, the communication operation by the PLC adapter 1 will be described with reference to FIGS.

  Mode information MI is stored in the setting information section 10 of the PLC adapter 1 in advance, and the mode information MI indicates an error correction code setting condition (hereinafter referred to as “mode”). There are two types of error correction code modes. Hereinafter, a mode with a low error correction capability is referred to as a “normal mode”, and a mode with a high error correction mode is referred to as an “enhanced mode”. “MIL” and mode information MI indicating the enhancement mode are referred to as “MIH”. Here, it is assumed that mode information MIL is stored in setting information unit 10 as a default.

  As the error correction code, a Reed-Solomon code method is set. In the normal mode, RS (255, 239) is used by the first RS modulator 58 (see FIG. 2) of the error correction modulator 51 and the first RS demodulator 68 (see FIG. 3) of the error correction demodulator 65. It is like that. On the other hand, in the enhanced mode, the RS (255, 15) is used by the second RS modulator 59 (see FIG. 2) of the error correction modulator 51 and the second RS demodulator 69 (see FIG. 3) of the error correction demodulator 65. It has come to be.

In performing the communication operation, first, the setting information unit 10 sends the stored mode information MIL to the error correction modulator 51 of the transmission unit 5 and the reception unit 6 via the control unit 8 as shown in FIG. Output to error correction demodulator 65. Upon receiving the mode information MIL, the transmission selector 57 of the error correction modulator 51 selects the first RS modulator 58 shown in FIG. 2 as the RS modulator, and
The reception selector 67 of the error correction demodulator 65 selects the first RS demodulator 68 shown in FIG. 3 as the RS demodulator. That is, the error correction code is set to the normal mode.

  When performing a transmission operation in this state, the home appliance 3 outputs transmission data SD to the PLC adapter 1 as shown in FIG. The transmission data SD is input to the error correction modulator 51 of the transmission unit 5 via the controller 9. Since the error correction modulator 51 uses RS (255, 239) as described above in the normal mode, the first RS modulator 58 selected by the transmission selector 57 converts the data length into the 239-byte transmission data SD. Is composed of a data block having a code length of 255 bytes to which a parity (redundant bit) consisting of 16 bytes is added, and encodes transmission data SD.

  The error correction modulator 51 modulates the encoded transmission data SD, and the wavelet inverse transformer 52 performs wavelet inverse transformation on the modulated transmission data SD to generate digital signal transmission data SD. The D / A converter 53 converts the generated transmission data SD from a digital signal to an analog signal, and the transmission amplifier 54 amplifies the transmission data SD converted to the analog signal. The band pass filter 55 extracts a necessary signal component from the amplified transmission data SD and outputs the transmission data SD to the power line 2 via the power line coupling unit 7. That is, the transmission data SD output from the home appliance 3 is superimposed on the power line 2 and transmitted to, for example, another home appliance (not shown).

  Although the wavelet transform method has been shown as the transform method between the time domain and the frequency domain, the present invention is not limited to this, and for example, a Fourier transform method may be used. Further, although the OFDM (Orthogonal Frequency Division Multiplex) modulation system has been shown as the modulation system, it is not particularly limited to this, and for example, a spread spectrum modulation system may be used.

  On the other hand, when performing a reception operation, for example, another household electrical appliance (not shown) outputs reception data RD to the power line 2. The reception data RD is transmitted to the PLC adapter 1 via the power line 2, and the reception unit 6 of the PLC adapter 1 receives the received reception data RD via the power line coupling unit 7, as shown in FIG. . The band pass filter 61 of the reception unit 6 extracts a necessary signal component from the received reception data RD, and the amplification degree controller 62 amplifies the reception data RD from which the necessary signal component is extracted. The A / D converter 63 converts the amplified reception data RD from an analog signal to a digital signal, and the wavelet converter 64 performs wavelet conversion on the reception data RD converted to the digital signal.

  The error correction demodulator 65 demodulates the wavelet-transformed reception data RD and decodes the demodulated reception data RD. That is, since the error correction demodulator 65 uses RS (255, 239) in the normal mode as in the error correction modulator 51, the first RS modulator 68 selected by the reception selector 67 receives the demodulated reception signal. An error is detected from the data RD, and the detected error is corrected. Therefore, errors are corrected up to a maximum of 8 bytes in the code length of 255 bytes.

  Thus, the communication operation is performed, for example, noise is generated from other home appliances (or impedance loss is changed due to a change in the number of home appliances connected to the power line 2), and the number of errors in the received data RD. Is over 8 bytes. The controller 9 monitors the number of errors in the received data RD detected by the error correction demodulator 65. When the number of errors reaches 8 bytes, the mode of the error correction code is changed from the normal mode to the enhanced mode. It is set to be.

Therefore, when the controller 9 detects that the number of errors has reached 8 bytes, the mode information MI stored in the setting information unit 10 is changed from the mode information MIL indicating the normal mode to the mode information MIH indicating the enhanced mode. Store update. When the mode information MIH is updated and stored, the setting information unit 10 sends the stored mode information MIH to the error correction modulator 51 and the reception unit of the transmission unit 5 via the control unit 8 as shown in FIG. 6 to the error correction demodulator 65. Upon receiving the mode information MIH, the transmission selector 57 of the error correction modulator 51 switches the RS modulator from the first RS modulator 58 to the second RS modulator 59, and the reception selector 67 of the error correction demodulator 65 The demodulator is switched from the first RS demodulator 68 to the second RS demodulator 69. That is, the error correction code is changed from the normal mode to the enhanced mode.

  When the error correction code is changed and set to the enhancement mode, in the transmission operation, the error correction modulator 51 of the transmission unit 5 encodes the transmission data SD in the enhancement mode. That is, since the error correction modulator 51 uses RS (255, 15) in the enhanced mode, the second RS modulator 59 switched by the transmission selector 57 converts the 15-byte transmission data SD into a data length of 240. A data block having a code length of 255 bytes to which parity (redundant bits) made up of bytes is added is configured to encode the transmission data SD. The transmission unit 5 performs the same processing as that in the normal mode on the encoded transmission data SD, and outputs it to the power line 2.

  On the other hand, in the reception operation, when the reception unit 6 receives reception data RD from another household electrical appliance, the reception unit 6 performs the same processing as the normal mode on the received reception data RD, and decodes the reception data RD. Turn into. That is, since the error correction demodulator 65 of the receiving unit 6 uses RS (255, 15), the second RS demodulator 69 switched by the reception selector 67 detects an error from the received data RD and detects the detected error. Is corrected. Therefore, in the code length of 255 bytes, the maximum number of errors that can be corrected increases from 8 bytes to 120 bytes, and errors are corrected within a range not exceeding 120 bytes, and communication is maintained. become. However, in this case, the transmission data SD is reduced from 239 bytes to 15 bytes in the code length of 255 bytes, so that the communication speed is reduced accordingly.

  In this way, when the communication operation is performed in the enhanced mode, noise generated from other home appliances is reduced again, and the number of errors in the received data RD becomes lower than 8 bytes, the controller 9 has an error number of 8 bytes. The lower level is detected, and the mode information MI stored in the setting information unit 10 is updated and stored from the mode information MIH indicating the enhanced mode to the mode information MIL indicating the normal mode. Therefore, the transmission selector 57 of the error correction modulator 51 switches the RS modulator from the second RS modulator 59 to the first RS modulator 58, and the reception selector 67 of the error correction demodulator 65 switches the RS demodulator. The 2RS modulator 69 is switched to the first RS demodulator 68. That is, the error correction code is changed from the enhanced mode to the normal mode again.

  As a result, the maximum number of errors that can be corrected is reduced from 120 bytes to 8 bytes. However, as described above, since noise from other home appliances is reduced, communication is maintained without any problem. Since the correction error code is changed to the normal mode, the transmission data SD increases from 15 bytes to 239 bytes again, so that the communication speed is recovered.

  As described above, in the communication apparatus according to the first embodiment, the error correction code is changed and set according to the number of errors in the reception data RD. Therefore, the reception can be performed without excessively increasing the error correction capability of the error correction code. Error correction of data RD can be performed. As a result, even if the number of errors changes and the communication state (for example, the SN ratio) is not stable, such as power line carrier communication, the communication speed is reduced while maintaining communication reliability. It can be reduced as much as possible.

Further, since the data length of redundant bits is changed as the error correction code change setting, fine error correction can be performed. As a result, error correction can be performed efficiently, waste of error correction capability is reduced, and a reduction in communication speed can be further reduced.

  In the above-described first embodiment, the case where the error correction code is changed and set according to the number of errors of the reception data RD has been described. However, if the error correction code is changed and set according to the parameter indicating the degree of error, The number of errors is not necessarily required. For example, the error correction code may be changed and set according to the error rate of the reception data RD. Further, although the case where the number of errors of 8 bytes is set as the threshold has been described, it is not necessarily 8 bytes and is arbitrary. Furthermore, the threshold value does not need to be one and may be a plurality. For example, it is possible to set a plurality of threshold values and change the redundant bits step by step. In this case, the RS modulator of the error correction modulator 51 and the RS demodulator of the error correction demodulator 65 may be provided in the same number as the threshold (three each when there are three thresholds). By doing so, error correction can be performed more finely, and the efficiency of error correction can be further improved.

  In the first embodiment described above, the Reed-Solomon code is shown as the error correction code method. However, the present invention is not particularly limited to this. Any error correction method such as a Treasury code may be used.

  In the first embodiment described above, the PLC adapter is shown as an example of the communication device. However, various configuration modes are possible as long as the device has a communication function. For example, it may be a semiconductor element having a communication function, or may be an electric device having a communication function (such as a personal computer, a printer, a copier, a telephone, or a facsimile). Such electrical devices include home appliances having a communication function (so-called home appliances such as a television and a DVD [Digital Versatile Disk] recorder). By using such various configuration modes, it is possible to provide a product that is easy to use.

  In Embodiment 1 described above, a communication device that transmits and receives communication data is shown. However, the communication device is not necessarily a communication device, and may be a reception device.

(Embodiment 2)
Next, the communication apparatus according to the second embodiment will be described. The second embodiment is different from the first embodiment only in the configuration in the error correction modulator 51 and the error correction demodulator 65. The same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Is omitted.

  FIG. 4 is a block diagram showing the error correction modulator 51 of the transmission unit 5 in the second embodiment. The error correction modulator 51 includes a transmission selector 57, a first RS modulator 58, and a Turbo (turbo) modulator 70 as shown in the broken line frame in FIG.

  FIG. 5 is a block diagram showing the error correction demodulator 65 of the receiving unit 6 in the second embodiment. The error correction demodulator 65 includes a reception selector 67, a first RS demodulator 68, and a Turbo demodulator 71, as shown in the broken line frame in FIG.

  In the above configuration, the communication operation by the PLC adapter 1 according to the second embodiment will be described with reference to FIGS. 1, 4, and 5.

As in the first embodiment, two types of error correction code modes (normal mode and enhanced mode) are prepared. However, unlike the first embodiment, the error correction code is a Reed-Solomon code and A system with a turbo code is set. In the normal mode, the Reed-Solomon code RS (255, 239) is used by the first RS modulator 58 of the error correction modulator 51 and the first RS demodulator 68 of the error correction demodulator 65. On the other hand, in the enhancement mode, a turbo code is used by the Turbo modulator 70 of the error correction modulator 51 and the Turbo demodulator 71 of the error correction demodulator 65. Note that the error correction code scheme is not limited to the above-described combinations, and three or more combinations are possible.

  Since the RS (255, 239) is used in the normal mode as in the first embodiment, the description of the communication operation is omitted. It is assumed that the communication operation is performed in the normal mode, for example, a random error (or burst error) occurs, and the number of errors in the received data RD reaches 8 bytes. Similarly to the first embodiment, the controller 9 updates and stores the mode information MI stored in the setting information unit 10 from MIL to MIH, and the transmission selector 57 of the error correction modulator 51 selects the modulator. While switching from the 1RS modulator 58 to the Turbo modulator 70, the reception selector 67 of the error correction demodulator 65 switches the demodulator from the first RS demodulator 68 to the Turbo demodulator 71. That is, the error correction code system is changed from the Reed-Solomon code to the turbo code.

  When the error correction code system is changed to the turbo code, in the transmission unit 5, the Turbo modulator 70 of the error correction modulator 51 encodes the transmission data SD using the turbo code. In the receiving unit 6, the Turbo demodulator 71 of the error correction demodulator 65 decodes the received data RD using a turbo code.

  Turbo code is a combination of a soft-in / out decoder that performs repetitive operation with a simple separation code and interleaver. By narrowing the gap to the theoretical limit (Shannon limit), error correction capability is improved compared to Reed-Solomon code. It has improved. As a result, any type of error, random error or burst error, can be corrected.

  Therefore, the Turbo demodulator 71 detects an error from the received data RD and corrects the detected error regardless of whether the type of error that occurs is a random error or a burst error. It will be maintained without problems.

  As described above, in the communication apparatus according to the second embodiment, since the error correction code scheme is changed and set, the type of error that occurs (for example, random error, burst error, byte error) changes. However, it is possible to select an error correction code method suitable for the type of error, and to further improve the reliability of communication.

(Embodiment 3)
Next, a communication apparatus according to Embodiment 3 will be described. FIG. 6 is a block diagram illustrating a communication apparatus according to the third embodiment. The communication apparatus according to the third embodiment is, for example, a PLC adapter 1 as in the first embodiment, and the PLC adapter 1 includes a display unit 11 connected to a controller 9. The display unit 11 may be in any display form as long as the user of the PLC adapter 1 can visually recognize the displayed information. For example, the display unit 11 is a liquid crystal display or an EL (Electro Luminescent) display. Components other than the display unit 11 are the same as those of the communication apparatus according to the first embodiment shown in FIG.

  In the above configuration, the communication operation by the PLC adapter 1 according to the third embodiment will be described with reference to FIG.

The controller 9 monitors the communication state (for example, the SN ratio) of the reception data RD based on the reception data RD output from the error correction demodulator 65 of the reception unit 6 and generates image data indicating the communication state. To do. The display unit 11 displays the generated image data in a predetermined display mode (for example, a numerical value or a gauge).

  For example, it is assumed that noise is generated from another household electrical appliance and the number of errors in the reception data RD approaches the maximum number of errors that can be corrected. Since the display unit 11 displays the image data indicating the deteriorated communication state, the user of the PLC adapter 1 can confirm that the error correction capability has no room for the communication state by looking at the displayed communication state. I can know.

  As described above, in the communication device according to the third embodiment, the user of the communication device can know the communication state of the received data RD via the display unit 11, so that the number of errors in the received data RD is Communication can be maintained by the user using a communication outlet change or a noise-compatible device so that the maximum number of errors that can be corrected is not exceeded.

  In the above-described third embodiment, an example in which the communication state is displayed has been described. However, not only the communication state is displayed, but, for example, the number of errors in the received data RD approaches the maximum number of errors that can be corrected. In this case, the alarm may be output as an image or sound. As a result, it is possible to promptly notify the user that there is no margin for error correction capability with respect to the communication state. Further, the mode of the error correction code (for example, the normal mode is “LOW” and the enhancement mode is “HIGH”) may be displayed together with the communication state. Furthermore, although the display unit 11 is shown as an example of a user interface that outputs a communication state, the communication state is not necessarily displayed as an image. For example, the communication state may be output as sound to a speaker.

  In addition, in Embodiment 3 mentioned above, although the case where the communication state was displayed on the display part 11 which own PLC adapter 1 had was demonstrated, it is not necessarily displayed on the display part 11 which own PLC adapter 1 has, For example, the communication state can be displayed on another communication device (for example, a mobile communication device such as a mobile phone or a PHS) via the network.

(Embodiment 4)
Next, a communication apparatus according to the fourth embodiment will be described. FIG. 7 is a block diagram showing a communication system according to the fourth embodiment. As illustrated in FIG. 7, the communication system 100 includes a server 103 and a home gateway 102 connected to a network 101 such as an Internet connection network, and a communication device 1 connected to the home gateway 102. The configuration of the communication device 1 is the same as that of the PLC adapter 1 shown in FIG.

  In the above configuration, a communication operation by the communication system 100 will be described with reference to FIG.

  The controller 9 (not shown) of the communication device 1 monitors the communication state for the received data RD, as in the third embodiment. The controller 9 transmits the monitored communication state to the server 103 via the network 101 via the home gateway 102.

  For example, it is assumed that noise is generated from another household electrical appliance and the number of errors in the reception data RD approaches the maximum number of errors that can be corrected. The controller 9 transmits the deteriorated communication state to the server 103, and the administrator of the server 103 can know that there is no margin for error correction capability with respect to the communication state by the transmitted communication state.

As described above, in the communication system according to the fourth embodiment, since the server 103 receives the communication state of the received data RD from the communication device 1, the administrator of the server 103 has sufficient error correction capability for the communication state. If not, for example, in cooperation with a service management company, it is possible to provide a service for changing communication outlets or providing noise-compatible devices, and to maintain communication.

  In addition, in Embodiment 4 mentioned above, the case where the communication state with respect to the single communication apparatus 1 was managed was demonstrated, However, You may make it manage the communication state respectively corresponding to the some communication apparatus 1. FIG. For example, the server 103 may manage information indicating each communication state in association with fixed information such as customer information, a manufacturing number, and shipping country information in the communication device 1. By doing so, the administrator of the server 103 can provide a fine-grained service to each user of the plurality of communication apparatuses 1 in cooperation with, for example, a service management company.

  In the fourth embodiment described above, the configuration shown in FIG. 7 is shown as an example of the communication system 100. However, the configuration is not particularly limited to this. For example, the communication device 1 directly connects to the network 101 without passing through the home gateway 102. A connected configuration may be used. In addition, the network is not particularly limited to the Internet connection network as long as the communication device 1 can be connected. For example, an integrated digital communication network such as ISDN (Integrated Services Digital Network), an international public network, a cable modem network, DSL It may be a (Digital Subscriber Line) modem network, FTTH (Fiber to the Home), or an intranet network uniquely constructed in the enterprise. Further, as long as the Internet connection network can provide an IP (Internet Protocol) layer in OSI (Open Systems Interconnection), it may be an open wide area network or an intranet network uniquely constructed in the company. Further, no special limitation is required for the physical layer, the data link layer, and the network layer.

  In the communication system 100, the connection means between the communication device 1 and the network 101 is at least one or more of power lines, copper wires, twist lines, coaxial cables, wireless, Ethernet (registered trademark), telephone lines, and the like. Any connection means may be used as long as they are connected by means, and the type and number of physical layers of the interface are not limited.

  The present invention can be applied to a communication device, a receiving device, a communication method, and a communication system that perform error correction of communication data based on an error correction code, and the communication state of communication data is not stable. However, the communication speed can be reduced as much as possible while maintaining the communication reliability.

FIG. 2 is a block diagram illustrating a communication device according to the first embodiment. FIG. 3 is a block diagram illustrating an error correction modulator of a transmission unit according to the first embodiment. FIG. 3 is a block diagram illustrating an error correction demodulator of a receiving unit in the first embodiment. FIG. 9 is a block diagram showing an error correction modulator of a transmission unit in the second embodiment. FIG. 9 is a block diagram showing an error correction demodulator of a receiving unit in the second embodiment. FIG. 9 is a block diagram illustrating a communication device according to a third embodiment. Block diagram showing a communication system according to Embodiment 4

Explanation of symbols

1 PLC adapter, communication device (communication device, receiving device)
2 Power Line 5 Transmitting Unit 6 Receiving Unit 8 Control Unit (Code Setting Unit)
9 Controller (sign setting control unit, communication state monitoring unit, communication state output unit, communication state notification unit)
10 Setting information part (code setting control part)
11 Display (predetermined user interface)
51 Error correction modulator (encoder)
52 Wavelet inverse transformer (wavelet inverse transformer)
57 Transmission selector (code setting unit)
64 Wavelet transformer (wavelet transformer)
65 Error correction demodulator (decoding unit)
67 Receive selector (sign setting part)
100 communication system 101 network 103 server RD transmission data (communication data)
SD received data (communication data)

Claims (9)

A communication device that transmits and receives communication data and performs error correction of the communication data based on an error correction code,
A code setting unit for setting the error correction code;
An encoding unit for adding redundant bits based on the error correction code set by the code setting unit to the communication data;
A transmission unit for transmitting communication data to which redundant bits are added by the encoding unit;
A receiving unit for receiving transmitted communication data;
Based on the error correction code set by the code setting unit, a decoding unit that detects an error in the communication data received by the receiving unit and corrects the detected error;
A code setting control unit that controls the code setting unit so as to change and set the error correction code set by the code setting unit according to the degree of error detected by the decoding unit;
A communication device. The code setting control unit controls the code setting unit to change and set the data length of redundant bits based on the error correction code set by the code setting unit;
The communication apparatus according to claim 1. The code setting control unit controls the code setting unit to change and set the error correction code method set by the code setting unit to a different method;
The communication apparatus according to claim 1. The transmission unit transmits the communication data to which the redundant bit is added via a power line,
The receiving unit receives the transmitted communication data via the power line;
The communication apparatus according to claim 1. The transmission unit has a wavelet inverse transform unit for performing wavelet inverse transform and transmitting communication data to which redundant bits are added by the encoding unit,
The receiving unit includes a wavelet transform unit that receives the transmitted communication data by wavelet transform,
The communication apparatus according to claim 1. A communication state monitoring unit that monitors a communication state of communication data received by the receiving unit;
A communication state output unit that outputs a communication state of communication data monitored by the communication state monitoring unit to a predetermined user interface;
The communication apparatus according to claim 1. A communication system having a communication device and a server according to claim 6 connected to a network,
The communication device further includes a communication state notification unit that notifies the server of a communication state of communication data monitored by the communication state monitoring unit.
A communication system characterized by the above. A receiving device that receives communication data and performs error correction on the communication data based on an error correction code,
A code setting unit for setting the error correction code;
A receiving unit for receiving transmitted communication data;
Based on the error correction code set by the code setting unit, a decoding unit that detects an error in the communication data received by the receiving unit and corrects the detected error;
A code setting control unit that controls the code setting unit so as to change and set the error correction code set by the code setting unit according to the degree of error detected by the decoding unit;
A receiving apparatus. A communication method for transmitting and receiving communication data and performing error correction on the communication data based on an error correction code,
Set the error correction code,
A redundant bit based on the set error correction code is added to the communication data,
Sending communication data with the redundant bit added;
Receive incoming communication data,
Detecting an error in the received communication data based on the set error correction code, and correcting the detected error;
Changing and setting the set error correction code according to the detected error degree;
A communication method characterized by the above.

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