JP2007306212A - Transmitter, receiver, communication system, and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitter and a receiver capable of keeping DC balance and performing high-speed communication even while errors are corrected. <P>SOLUTION: To digital transmission signal Ss, first to fourth signal processing means 11A to 11D and pluralities of identification number adding units 16, inverting units 17, and specific code inserting units 18 perform four kinds of signal processing for (0) no conversion, (1) voltage inversion, (2) specific-code insertion, and (3) voltage inversion by other signal insertion to generate a plurality of processed data, and a selecting unit 13 selects one of a plurality of processed data generated by adding error correction codes to those generated processed data by error correcting units 12A to 12D to generate transmission data, which is transmitted to the receiver 2A through a communication line 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmitter for transmitting an encoded digital signal to a communication path by DC balance, a receiver for demodulating the encoded digital signal, a communication system using these receiver and receiver, and It relates to a communication method.

  As a conventional encoding method for transmitting a digital signal, for example, “0101” is added before adding an error correction code in order to improve DC balance that occurs when an error correction code is added to data. By adding a code, a technique is known in which transmission data does not disturb DC balance so much even if the actual data portion is all 0s or all 1s (see Patent Document 1).

In addition, as a conventional encoding method when transmitting a digital signal, for example, even when the same data is transmitted, a process of dynamically deciding whether or not to perform bit inversion depending on the case and performing bit inversion appropriately After adding information on whether or not the data is bit-inverted, an error correction code is added and transmitted. On the receiving side, the original data is restored by error correction, and then the inverted bit 1 is checked and the bit is checked. Is inverted, the original data is restored by inverting the data. If the bit is not inverted, a technique of outputting only by deleting one bit is known (see Patent Document 2).
Japanese Patent Laid-Open No. 61-100059 JP 11-68859 A

  However, according to the conventional invention of Patent Document 1, since the bit string “0101” added at the time of calculating the error correction code is not transmitted, the transmission data does not increase so much, but the unit for improving the DC balance is the error correction code. Therefore, when the same data continues, the DC balance cannot be improved.

  Further, according to the invention of Patent Document 2, since it is possible to dynamically determine whether to invert a data bit, it is possible to select whether to invert the bit as appropriate in a direction in which DC balance is improved while transmitting data. However, the amount of data increases by adding a bit indicating whether or not bit inversion has been performed.

  In addition, since none of the above methods is considered for non-binary encoding, it is difficult to apply to DC balance in multi-level communication, and it is more preferable to lower the average slew rate than DC balance. When it becomes a subject etc., application becomes difficult.

  Accordingly, an object of the present invention is to provide a transmission device, a reception device, a communication system, and a communication method that can perform error correction and perform high-speed communication suitable for characteristics of a communication channel such as DC balance and slew rate. There is to do.

  In order to achieve the above object, one embodiment of the present invention provides the following transmission device, reception device, communication system, and communication method.

[1] Processing means for generating a plurality of processed data by applying a plurality of types of processing to data to be transmitted; processing means for performing processing for adding an error correction code to each of the plurality of processed data;
Selection means for selecting one processing data as a transmission data from a plurality of processing data processed by the processing means, and transmitting the transmission data without adding information indicating the type of processing by the processing means; A transmission apparatus comprising:

  According to the transmission device having the above-described configuration, the transmission device includes selection means for selecting one processing data for a plurality of processing data obtained by performing a plurality of types of signal processing on a signal to be transmitted. One optimum processing data can be selected according to the characteristics of the communication path such as the slew rate. Further, by transmitting the transmission data without adding information indicating the type of processing by the processing means, an increase in the amount of transmission data can be suppressed and high-speed communication is possible.

[2] The selection unit includes a DC balance monitoring unit that monitors a DC balance of the processing data, and selects the one processing data having a good DC balance based on a monitoring result of the DC balance monitoring unit. The transmitter according to [1], characterized in that it is characterized in that Thereby, transmission efficiency improves.

[3] The selection unit includes a slew rate setting unit for setting a slew rate, and selects the one processing data with a good slew rate based on the setting content of the slew rate setting unit. The transmission device according to [1]. This enables transmission with a low error rate.

[4] The selection unit includes a DC balance monitoring unit that monitors a DC balance of the processing data and a slew rate setting unit that sets a slew rate, and the DC balance is determined based on a monitoring result of the DC balance monitoring unit. The transmission apparatus according to [1], wherein the one processing data that is good and has a good slew rate is selected based on a setting content of the slew rate setting unit. With this configuration, transmission efficiency is improved and transmission with a low error rate is possible.

[5] Inverse conversion means for generating a plurality of inverse conversion data by applying a plurality of types of inverse conversion to the data to which the error correction code is added; processing means for performing error correction processing on the plurality of inverse conversion data; A receiving apparatus comprising: selecting means for selecting one processed data as received data from a plurality of processed data processed by the processing means.

  According to the receiving apparatus having the above configuration, a plurality of signal processing that would have been performed on the transmission side is reproduced by the inverse conversion means, and one of the inversely converted data satisfying the condition that the error rate is the smallest among them is obtained. By selecting with the selection means, communication with a low error rate, that is, high-speed communication becomes possible.

[6] The selection unit according to [5], wherein the selection unit selects, as the reception data, the one processing data having the lowest error rate based on an error correction code among the plurality of processing data. Receiver device. As a result, the transmission data can be restored.

[7] The selection unit includes a DC balance monitoring unit that monitors a DC balance of the processing data, has the lowest error rate, and has a good DC balance based on a monitoring result of the DC balance monitoring unit. The receiving apparatus according to [6], wherein two pieces of processing data are selected. Thereby, transmission efficiency improves.

[8] The selection means includes a slew rate setting unit for setting a slew rate, and has the lowest error rate and the one processing data with a good slew rate based on the setting contents of the slew rate setting unit. The receiving apparatus according to [6], wherein the receiving apparatus is selected. This enables transmission with a low error rate.

[9] The selection unit includes a DC balance monitoring unit that monitors the DC balance of the previous processing data and a slew rate setting unit that sets a slew rate, and has the lowest error rate, and is monitored by the DC balance monitoring unit. The method [6] is characterized in that the one processing data having a good DC balance based on the result and a good slew rate is selected based on the setting content of the slew rate setting unit. Receiver device. With this configuration, transmission efficiency is improved and transmission with a low error rate is possible.

[10] The transmission apparatus according to any one of [1] to [4] and any one of [5] to [9] connected to the transmission apparatus via a communication path. A communication system comprising the receiving device described above.

[11] A plurality of types of processing are performed on the data to be transmitted to generate a plurality of processing data, an error correction code is added to each of the plurality of processing data, and the plurality of processing data is processed Selecting one processing data from a plurality of processing data as transmission data, transmitting the transmission data without adding information indicating the type of processing, and performing a plurality of types of inverse transformation on the received data received, An error correction process is performed on the plurality of inverse transform data,
One communication data is selected as received data from a plurality of processed data processed for the plurality of inversely transformed data.

  According to the communication system and the communication method configured as described above, on the transmission side, depending on the DC balance, the characteristics of the communication path, etc., for a plurality of processing data obtained by performing a plurality of types of signal processing on the signal to be transmitted. Select and transmit one optimal processing data, perform multiple inverse transforms corresponding to multiple signal processing performed on the receiving side on the receiving side, and reverse the conditions that satisfy the minimum error rate among them By selecting one of the conversion data, high-speed communication with a low error rate becomes possible.

  According to the present invention, error correction is possible, and high-speed communication suitable for characteristics of a communication path such as DC balance and slew rate can be performed.

[First Embodiment]
(Configuration of communication system)
FIG. 1 shows a configuration of a communication system and a transmission apparatus according to the first embodiment of the present invention. The configuration of the transmission device is shown in FIG. The communication system 10 transmits a multi-value data string from the transmission device 1A to the reception device 2A via the communication path 3.

(Configuration of transmitter)
As shown in FIG. 1, the transmission apparatus 1A includes first to fourth signal processing means 11A to 11D that perform four types of signal processing on the transmission signal Ss to be transmitted to the reception apparatus 2A, and first to fourth signal processing units 11A to 11D. First to fourth error correction units 12A to 12D as processing means for adding an error correction code (ECC) to the output signals of the fourth signal processing means 11A to 11D, and first to fourth A selection unit 13 that selects any one of the processing results by the error correction units 12A to 12D, a slew rate setting unit 15 that is connected to the selection unit 13 and sets a slew rate, and a processing result that is selected by the selection unit 13 And a multi-value conversion unit 19 that outputs the signal to the communication path 3 as a transmission signal St. The slew rate refers to a voltage that can transition in unit time.

(Signal processing means)
The first signal processing unit 11A includes an identification number adding unit 16 that adds an identification number indicating what kind of signal processing the self has performed to the head of the output data. The second signal processing unit 11B includes an identification number adding unit 16 and an inversion unit 17 that inverts data. The third signal processing means 11C includes an identification number adding unit 16 and a specific code inserting unit 18 for inserting a specific code for DC balance in the data. The fourth signal processing unit 11 </ b> D includes an identification number adding unit 16, an inverting unit 17, and a specific code inserting unit 18.

(Error correction part)
The first to fourth error correction units 12A to 12D generate a correction code using a known technique such as a Bose-Chaudhuri hocquenghem Code (BCH) code, a Hamming code, or a Reed-Solomon code, for example. To do.

(Selection part)
The selection unit 13 includes an integrator 14 as a DC balance monitoring unit that integrates a transmission signal, and among the processing results of the first to fourth error correction units 12A to 12D, the integration value by the integrator 14 and the slew rate One processing result is selected based on the setting content of the setting unit 15.

(Integrator)
FIG. 2 shows the processing of the integrator. When the transmission signal St is given as shown in the upper part of FIG. 2, the low frequency component may be limited by the frequency filter on the communication path 3. In this case, low frequency components that could not be passed are accumulated, and if a certain value is exceeded, the transmission signal may be distorted or lost. In the example of FIG. 2, the communication is started at time t0, and the integral value once reaches the lower limit at time t1, but then the accumulation of low frequency components is canceled by the high voltage level signals such as code 2 and code 3. Has been. However, it can be seen that the subsequent signal exceeds the lower limit at time tL, causing a problem in signal transmission. Therefore, a limit is provided for DC balance so that the integrated value of the signal voltage does not exceed ± 3 V, for example.

(Slew rate setting part)
FIG. 3 is a diagram for explaining the slew rate setting unit 15 and shows a signal waveform of the transmission signal St by a quaternary code. The communication path 3 transmits multi-valued data consisting of code 0 to code 3 as a transmission signal St. Here, as shown in FIG. 2, it is assumed that the quaternion code is constituted by four kinds of voltages of + 1.5V, + 0.5V, -0.5V, and -1.5V. When performing high-speed communication, the slew rate becomes a problem, and the signal quality is remarkably observed at the transition from +1.5 V to -1.5 V and from -1.5 V to +1.5 V between adjacent codes. Getting worse. For example, in the transition from the code 0 to the code 1 or 2, the specified voltage is reached between the time t0 and the measurement point ts, but the transition from the code 0 to the code 3 is insufficient. May be mistaken for code 2.

  Therefore, the slew rate setting unit 15 is configured to be able to set a voltage that can transition between adjacent signals. For example, when 2V is set, transition from code 0 to code 1 or code 2 is possible, but when transition to code 3 is made, there is a possibility that a transition to code 2 may be mistaken.

(Four rules for selection by the selector)
4 to 7 are waveform diagrams before and after processing by the first to fourth signal processing means. 4 to 7, (a) shows a waveform before signal processing, and (b) shows a waveform after signal processing.

  The selection unit 13 selects a signal sequence according to four rules (1) to (4) described below.

  Rule (1): Based on the output of the integrator 14, the selection unit 13 can determine that the DC balance is currently sufficient and that the DC balance will not be deteriorated by the next signal to be transmitted. If it can be determined that there is no problem in the slew rate in terms of performance of the communication path 3 based on the setting contents of the setting unit 15, no conversion is applied. That is, the signal is processed by the first signal processing means 11A, and the processing result by the first error correction unit 12A is selected.

  For example, when the integration value of the current signal voltage is 0V and the signal changes to + 0.5V, -0.5V, + 0.5V, and -0.5V as shown in FIG. As shown in FIG. 4B, no conversion is applied.

  Rule (2): Based on the output of the integrator 14, the selection unit 13 currently has a DC balance that is unbalanced above a certain level, and the signal to be transmitted next may exceed the limit of the communication path 3. If it can be determined that there is no problem in the slew rate in terms of performance of the communication path 3 based on the setting contents of the slew rate setting unit 15, voltage inversion is applied. That is, the signal is processed by the second signal processing unit 11B and the processing result by the second error correction unit 12B is selected.

  For example, as shown in FIG. 5A, the integration value of the current signal voltage by the integrator 14 is 2V, and the signal is changed to + 0.5V, + 1.5V, -0.5V, + 0.5V. In this case, if signal transmission is performed as it is, the integral value exceeds the limit of the communication path 3 when the second code (+1.5 V) is transmitted. Therefore, as shown in FIG. 5B, the voltage is inverted by the inversion unit 25 to invert the signal so as not to exceed the limit, and the DC balance imbalance is improved.

  Rule (3): Based on the output of the integrator 14, the selector 13 can determine that the DC balance is currently sufficiently high and that the DC balance will not be deteriorated by the next signal to be transmitted. If it can be determined that there is a problem with the slew rate in terms of performance of the communication path 3 based on the setting contents of the setting unit 15, insertion of another code is applied. That is, the signal is processed by the third signal processing means 11C and the processing result by the third error correction unit 12C is selected.

  For example, as shown in FIG. 6A, the integral value of the signal voltage is currently 0.5V, and the signal changes to + 1.5V, −1.5V, + 0.5V, and −0.5V. In this case, if the signal transmission is performed as it is, the amplitude from the first code (+ 1.5V) to the second code (−1.5V) is too large, and the second code may be mistaken. Therefore, as shown in (b) of FIG. 6, another code (here, −0.5 V) is inserted between +1.5 V and −1.5 V by the specific code insertion unit 18 of the transmission apparatus 1A. . Note that the signal width increases as the code is inserted.

  Rule (4): Based on the output of the integrator 14, the selection unit 13 is currently unbalanced beyond a certain DC balance, and may exceed the limit of the communication path 3 depending on a signal to be transmitted next. If it can be determined that there is a problem with the slew rate due to the performance of the communication path 3 based on the setting contents of the slew rate setting unit 15, the process of inverting the voltage after inserting another signal Apply. That is, the signal is processed by the fourth signal processing means 11D and the processing result by the fourth error correction unit 12D is selected.

  For example, as shown in FIG. 7A, when the integration value of the signal voltage is 2V and the signal changes to + 1.5V, −1.5V, and + 0.5V at present, As shown in b), the insertion of another code (here, -0.5 V) by the specific code insertion unit 18 and the inversion processing by the inversion unit 17 are simultaneously performed.

(Receiver configuration)
FIG. 8 shows a communication system and a receiving apparatus according to the first embodiment of the present invention. This receiving device 2A is connected to the transmitting device 1A of FIG.

  As shown in FIG. 8, the receiving device 2A performs first to second inverse transformations of four types of signal processing performed on the transmission side with respect to the transmission signal St transmitted from the transmitting device 1A via the communication path 3. Four inverse conversion units 21A to 21D, and first to fourth error correction units 22A to 22D as processing units for performing error correction on the output signals of the first to fourth inverse conversion units 21A to 21D; And a selection unit 23 that selects any one of the processing results of the first to fourth error correction units 22A to 22D and outputs the selected result as an output signal So. The selection unit 23 incorporates an integrator 27 similar to the transmission device 1A and is connected to a slew rate setting unit 28 similar to the transmission device 1A.

(Inverse conversion means)
The first inverse conversion means 21A includes an identification number adding unit 24 that adds an identification number to the input transmission signal St. The second inverse conversion means 21B includes an identification number adding unit 24 and an inversion unit 25 that inverts data for DC balance. The third inverse conversion means 21C includes an identification number adding unit 24 and a specific code extracting unit 26 that extracts a specific code from the data string. The fourth inverse conversion means 21D includes an identification number adding unit 24, an inverting unit 25, and a specific code extracting unit 26.

(Selection part)
1st thru | or 4th reverse conversion means 21A-21D performs reverse conversion with respect to four types of methods which the transmitter 1A performed, but if the communication path 3 is completely reliable, selection by the receiver 2A side Which of the first to fourth inverse transforming units 21A to 21D is used can be identified from the integral value of the signal voltage prepared by the unit 23 and the signal transition.

  However, if the communication path 3 cannot be trusted, there is a possibility that it may be mistaken for the mixed noise as if other signal processing means were used. Since the identification number is not transmitted through the communication path 3, no bit error occurs in the identification number. Therefore, the number of error bits is the smallest for other data string portions other than the identification number, and error correction is performed. When it is performed, when the load on the communication path 3 is the lowest, that is, when the above rules (1) to (4) are reasonably satisfied, it is applied by the signal processing means 11A to 11D selected on the transmission side. It can be estimated that the original information.

  Therefore, the selection unit 23 selects a data string that can be corrected with the least error among the four errors corrected by the first to fourth error correction units 22A to 22D, and the data string is integrated by the integrator 27. Based on the value and the setting content of the slew rate setting unit 28, a signal that satisfies any one of the rules (1) to (4) (lowest load) is output as the output signal So.

  However, if the code subjected to error correction has a high load on the communication path 3, that is, if the decoding result is in violation of the rules (1) to (4), error correction is performed. An impossible fatal error has occurred. In this case, the receiving device 2A takes measures such as requesting the transmitting device 1A to retransmit.

(Operation of the communication system according to the first embodiment)
Next, the operation of the communication system 10 according to the first embodiment will be described separately for the transmission operation by the transmission device 1A and the reception operation by the reception device 2A.

(Transmission operation of the transmitter)
Next, the transmission operation of the transmission apparatus 1A will be described with reference to FIG.

  FIG. 9 shows the processing flow of the transmission signal. First, as shown in FIG. 9A, the first to fourth signal processing means 11A to 11D perform four types of signal processing on the transmission signal Ss, and the identification number adding unit 16 starts the transmission signal Ss. Are added to the first to fourth error correction units 12A to 12D with the two-digit identification numbers “00”, “01”, “10”, and “11” added thereto.

  That is, the first signal processing unit 11A outputs the transmission signal Ss to the first error correction unit 12A without conversion. The second signal processing unit 11B inverts the voltage with respect to the transmission signal Ss by the inversion unit 17 and outputs the inverted signal to the second error correction unit 12B. The third signal processing unit 11C inserts a specific code into the transmission signal Ss by the specific code insertion unit 18 and outputs the signal to the third error correction unit 12C. The fourth signal processing means 11D inverts the voltage with respect to the transmission signal Ss by the inverting unit 17 and further inserts the specific code by the specific code inserting unit 18 and outputs it to the fourth error correcting unit 12D.

  As shown in FIG. 8B, the first to fourth error correction units 12A to 12D add the error correction codes ECC0 to ECC3 to the end of the transmission signal Ss to which the identification number is added, and send it to the selection unit 13. Output. The transmission signals Ss output from the first to fourth error correction units 12A to 12D are subjected to four types of signal processing by the first to fourth signal processing units 11A to 11D. There are four types of signal sequences as shown in c).

  Next, the selection unit 13 integrates the waveform of the transmission signal Ss with the integrator 14, and the first to fourth error correction units 12 </ b> A to 12 </ b> D based on the integration value and the setting content of the slew rate setting unit 15. Among the four data strings shown in (c) of FIG. 8, one of the data strings that is considered to be the most secure transmission without placing a burden on the communication path 3 is described above (1) to The selection is made according to the rule of (4), and the leading identification number is deleted and sent to the multi-value conversion unit 19.

  For example, if the communication path 3 strictly requires that the DC balance is satisfied, the encoded data string has a small DC component, and the communication path 3 has a characteristic in which the slew rate cannot be increased too much. The data string with the lowest slew rate is selected.

  The multi-value conversion unit 19 performs multi-value conversion on the data string from the selection unit 13 and then sends it to the communication path 3.

(Receiving operation of receiving device)
Next, the receiving operation of the receiving apparatus 2A will be described with reference to FIGS.

  FIG. 10 shows a flow of transmission signal processing. In the figure, the number before the code error indicates the number of error bits. As shown in FIG. 10, it is assumed that an error (Er) occurs in the data string of the transmission signal St on the communication path 3. The receiving device 2A inputs the transmission signal St received from the transmitting device 1A via the communication path 3 to the first to fourth inverse conversion units 21A to 21D. The first to fourth inverse transforming units 21A to 21D perform four types of inverse transforms on the transmission signal St, and the identification number adding unit 24 adds a two-digit identification number “00”, “ 01 "," 10 ", and" 11 "are added and output to the first to fourth error correction units 22A to 22D.

  That is, the first inverse conversion means 21A outputs the transmission signal St to the first error correction unit 22A by non-inverse conversion. The second inverse conversion means 21B inverts the data with respect to the transmission signal St by the inversion unit 25 and outputs the inverted data to the second error correction unit 22B. The third inverse conversion means 21C extracts the specific code from the transmission signal St by the specific code extraction unit 26 and outputs it to the third error correction unit 22C. The fourth inverse conversion means 21D inverts the data by the inverting unit 25 with respect to the transmission signal St, further extracts the specific code by the specific code extracting unit 26, and outputs it to the fourth error correcting unit 22D.

  As shown in FIG. 10, the first to fourth error correction units 22A to 22D add error correction codes ECC0 to ECC3 at the end of the transmission signal St output from the first to fourth inverse transforming units 21A to 21D. In addition, the selection unit 23 outputs the result.

  The selector 23 selects one code error (circled in FIG. 10) of the identification number “10” that can be corrected with the least error among the four errors corrected by the first to fourth error correction units 22A to 22D. A data string is selected, and the data string that satisfies any of the rules (1) to (4) (the lowest load) is output as the output signal So. In this way, an output signal So corresponding to the original transmission signal Ss is obtained.

(Effects of the first embodiment)
According to the first embodiment, the following effects are obtained.
(A) Since one output signal is selected from the output signals of the plurality of error correction units based on the integration value by the integrator and the setting contents of the slew rate setting unit, the communication path such as DC balance and slew rate is selected. Multi-value communication corresponding to the characteristics of.
(B) By transmitting without adding an identification number indicating which signal processing means is applied on the transmission side, it is possible to suppress an increase in the amount of transmitted data, and high-speed communication is possible even if error correction is performed. It becomes.
(C) In information communication, the encoding method is greatly limited by the characteristics of the communication path 3, but according to the first embodiment, a relatively free encoding method can be selected. For example, it is possible to select an encoding method that enables higher-speed communication depending on transmitted information. Further, by providing a degree of freedom in selecting the encoding method, it is possible to select means that can be implemented within the resources allowed for the communication device.
(D) The signal is encoded by the transmitting device 1A according to one or a plurality of rules shared by the transmitting device 1A and the receiving device 2A, and the receiving device 2A indicates which signal processing means is applied from the received data sequence by using an error correction code. Therefore, since the error can be estimated and decoded so that there are fewer errors, error correction can be performed with a simple configuration.

[Second Embodiment]
FIG. 11 shows the configuration of a communication system and a transmission device according to the second embodiment of the present invention, and FIG. 12 shows the configuration of a communication system and a reception device according to the second embodiment of the present invention. The communication system 10 transmits a binary data string from the transmission device 1B to the reception device 2B via the communication path 3.

  The transmission apparatus 1B according to the present embodiment targets a binary data string. In the transmission apparatus 1A according to the first embodiment, the third and fourth signal processing means 11, 11D, third, and fourth The error correction units 12C and 12D and the multi-value conversion unit 19 are removed, and a 1/0 counter 20 as a DC balance monitoring unit is provided in place of the integrator 14, and other configurations are the same as those in the first embodiment. It is the same as the form.

  The receiving apparatus 2B according to the present embodiment removes the third and fourth inverse transform units 21C and 21D and the third error correction units 22C and 22D from the receiving apparatus 2A according to the first embodiment, and integrates them. A 1/0 counter 29 is provided instead of the device 27, and the other configuration is the same as that of the first embodiment.

(Operation of the communication system according to the second embodiment)
Next, the operation of the communication system 10 according to the second embodiment will be described separately for the transmission operation by the transmission device 1B and the reception operation by the reception device 2B.

(Transmission operation of the transmitter)
Next, the transmission operation of the transmission apparatus 1B according to the second embodiment will be described. In the present embodiment, the transmission signal St on the communication path 3 is a binary encoded signal that takes only “0” or “1”, and the communication path 3 is a line that is severe in imbalance of DC balance. And Furthermore, if the data length is 3 bits and the signal processing by the first and second error correction units 12A and 12B is two types, that is, nothing is done (identification number: 0), linear conversion of the output value, specifically, 1-x is assigned to the code x to invert the bits (identification number: 1). The error correction code is assumed to be a Hamming code.

  First, the transmission signal Ss is input to the first and second signal processing means 11A and 11B. The first signal processing unit 11A performs two types of signal processing and adds “0” and “1” to the head of the transmission signal Ss by the identification number adding unit 16 to provide first and second error correction units. Output to 12A and 12B.

  That is, the first signal processing unit 11A outputs the transmission signal Ss to the first error correction unit 12A without conversion. The second signal processing unit 11B inverts the transmission signal Ss by the inversion unit 17 and outputs the inverted signal to the second error correction unit 12B. The first and second error correction units 12A. 12B adds error correction codes ECC0 and ECC1 to the end of the transmission signal Ss to which the identification number is added, and outputs it to the selection unit 13.

  Next, the selection unit 13 performs 0/1 counting on the data of the transmission signal Ss by the 0/1 counter 20, and the first and first counts are based on the 0/1 count and the setting contents of the slew rate setting unit 15. One of the two data strings from the two error correction units 12A, 12B is selected from one of the data strings that is considered to be the safest transmission without burdening the communication path 3, and The head identification number is deleted and sent to the communication path 3.

(2) Reception Operation Next, the operation of the reception device 2B will be described. The reception device 2B inputs the transmission signal St received from the transmission device 1A via the communication path 3 to the first and second inverse conversion units 21A and 21B. The first and second reverse conversion means 21A and 21B perform reverse conversion on the two methods that may have been performed by the transmission apparatus 1B. Specifically, when the above rules (1) and (2) are reasonably satisfied, the received signal is estimated to be the original information applied by the signal processing means selected on the transmission side. For all signal processing that may have been performed on the transmission side for the column, an identification number corresponding to each signal processing is added to the head of the data sequence by the identification number adding unit 24, and the inversion unit 25 is provided. Used to perform reverse conversion according to the identification number.

  The first and second error correction units 22A and 22B perform error correction on the output signals of the first and second inverse conversion units 21A and 21B. Finally, one of the output signals of the first and second error correction units 22A and 22B that seems to have been optimally processed is selected by the selection unit 23, whereby the output signal So is extracted as original data.

(Specific operation example)
Here, a specific operation example will be described. For example, as shown in Table 1, all data strings that can be considered when 3 bits of Hamming code are added to 4 bits obtained by adding 3 bits of data and identification numbers 1 bit of the first and second signal processing means 11A and 11B are as shown in Table 1. become.

実際に送信装置１Ｂから送信されるデータは、識別番号である先頭の１ｂｉｔを削除した６ｂｉｔである。この「００００００」の６ｂｉｔのデータは、元々「１１１１１１」であったデータを、０／１バランスを合わせるために反転したデータの可能性も、元々「１１１１１１」であった可能もある。

The data that is actually transmitted from the transmitting apparatus 1B is 6 bits obtained by deleting the first 1 bit that is the identification number. The 6-bit data of “000000” may be the data that was originally “111111” and inverted to match the 0/1 balance, or may be “111111”.

  Since it is impossible to decode without knowing either one, a common rule is determined as to when to invert data in both transmission and reception. Here, if the DC balance is improved with the following data, it is decided to “invert”. However, if the balance of “0” or “1” does not change, the data is transmitted without being inverted.

  For example, when the transmission device 1B wants to send data “000001010000” to the reception device 2B such as “000”, “001”, “010”, and “000” every three digits, the following encoding is performed. Note that the first digit after encoding represents the identification number, the next three digits represent the original data, and the last three digits represent the error correction code.

  The original data “000” is “0000000” or “1111111”, the original data “001” is “0001111” or “1110000”, and the original data “010” is “0010110” or “1101001”.

  Initially, since 0/1 count by the 0/1 counter 20 indicating the balance of DC balance is 0/0, “000000” is transmitted non-inverted. This gives a 0/1 count of 6/0. Next, the data to be transmitted is selected as non-inverted so as to improve the 0/1 count, and “001111” is transmitted. This gives a 0/1 count of 8/4. Next, it sends in reverse “101001” and 0/1 count is 11/7. If the next “000” is non-inverted and “000000” is sent, the 0/1 count becomes 17/7, which deteriorates the balance. Therefore, the inversion unit 17 inverts and transmits “111111”. In this case, 0/1 count is 11/13, and the balance is good.

  Therefore, the data reaching the receiving device 2B is “000000001111101001111111”. When this is decoded on the receiving side by the opposite procedure for “000000”, “001111”, “101001”, and “111111” every six digits, the original data “from“ 000000 ”is assumed to be non-inverted at first. 000 "is taken out. Assuming that the next data “001111” is “110000” assuming inversion, the DC balance is deteriorated. Therefore, the data “001” is taken out as “001111”. Similarly, since only the last data is improved by inversion, it is inverted and “000” is extracted.

  The processing up to this point is the same as the processing of 8B10B, but bit errors are considered here. There are two types of possible bit errors: a normal bit error and a decoding error due to a wrong DC balance determination due to the bit error.

  First, if the DC balance determination is not wrong, it is possible to know whether the data is inverted or non-inverted. Therefore, it is only necessary to perform error correction of 4 bits + 3 bits normally by adding the bit to the head. .

  On the other hand, in the case of an error due to a DC balance determination error, that is, “001111”, it is not known whether it is inverted data or non-inverted data. In this case, if “0001111” is assumed as non-inversion, there is no error, and “1001111” results in at least a 2-bit error, so “001” is adopted as non-inversion. If the original data does not fall within a 1-bit error regardless of whether it is inverted or non-inverted, an error of 2 bits or more must occur at the same time. Adopted by the selector 23.

(Effect of the second embodiment)
According to the second embodiment, the same effect as that of the first embodiment can be obtained with a simple configuration for binary data.

[Third Embodiment]
FIG. 13 shows a configuration of a communication system and a transmission device according to the third embodiment of the present invention, and FIG. 14 shows a configuration of a communication system and a reception device according to the third embodiment of the present invention.

  In the first embodiment, the transmission apparatus 1C according to the present embodiment is configured so that one error correction unit 12 instead of the four error correction units 12A to 12D outputs the first to fourth signal processing units 11A to 11D. The output signal is subjected to error correction, and the other configuration is the same as that of the first embodiment.

  The receiving apparatus 2C according to the present embodiment performs error correction on the output signals from the first to fourth inverse transform units 21A to 21D by one error correction unit 22 instead of the four error correction units 22A to 22D. The other configuration is the same as that of the first embodiment.

(Operation of the communication system according to the third embodiment)
Next, the operation of the communication system 10 according to the third embodiment will be described. First, as shown in FIG. 9A, the first to fourth signal processing units 11A to 11D of the transmission apparatus 1C are configured to perform four types of signal processing on the transmission signal Ss, that is, (1) no conversion described above ( 2) Voltage inversion, (3) Specific code insertion, (4) Voltage inversion and specific code insertion are performed, and the identification number adding unit 16 adds a two-digit identification number to the head of the transmission signal Ss, “00”, “01” , “10”, “11” are added.

  When the processing by the first to fourth signal processing units 11A to 11D is completed, the output signals are sequentially input to the error correction unit 22, and the error correction codes ECC0 to ECC3 are converted to the first to fourth signal processing units 11A. To the end of each transmission signal Ss from ˜11D.

  Next, the selection unit 13 selects one of the four data strings from the error correction unit 12A as one of the data strings that is considered to be the safest transmission without imposing a burden on the communication path 3. The selection is made according to the rules (1) to (4), the head identification number is deleted, and the result is sent to the multi-value conversion unit 19. At this time, the integrator 14 integrates the waveform of the transmission signal St, and the selection unit 13 selects a data string that averages the integral values, that is, can achieve DC balance. The multi-level conversion unit 19 performs multi-level modulation on the data string from the selection unit 13 and then transmits it to the communication path 3.

  The first to fourth inverse transforming units 21A to 21D of the receiving device 3C perform four types of inverse transforms on the transmission signal St, and the identification number adding unit 24 adds a two-digit identification number to the head of the transmission signal St, “ 00, “01”, “10”, and “11” are added.

  When the processing by the first to fourth inverse transform units 21A to 21D is completed, the output signals are sequentially input to the error correction unit 22, and the error correction codes ECC0 to ECC3 are converted to the first to fourth inverse transform units 21A. To the end of each transmission signal St from 21D.

  The selection unit 23 selects a data string that can be corrected with the least error among the four errors corrected by the error correction unit 22, and satisfies one of the rules (1) to (4) (the lowest load). ) Is output as the output signal So.

(Effect of the third embodiment)
According to the third embodiment, the same effects as those of the first embodiment can be obtained, and the configuration can be simplified as compared with the first embodiment.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the combination of the components between the embodiments can be arbitrarily performed.

  In the second embodiment, similarly to the third embodiment, the first and second error correction units 12A and 12B of the transmission device 1B are configured by one error correction unit 12, and the first of the reception device 2B. The first and second error correction units 22A and 22B may be configured by one error correction unit 22.

  For example, the transmission device may have a reception function as well as the reception device together with the transmission function, and the reception device may have a transmission function similar to that of the transmission device together with the reception function so that bidirectional communication is possible.

  As the signal processing means, four types of no conversion, voltage inversion, insertion of a specific code, voltage inversion and insertion of a specific code have been described. However, the present invention is not limited to this, and code position exchange, code string reduction, code Signal processing such as linear conversion of the output level, sum with a specific pattern, product with a specific pattern, etc. may be performed. You may make it the structure which performs conversion.

  Both the transmission device and the reception device may include encryption means that makes it difficult for a third party who is not time-synchronized to change by changing the set of conversion means by time-synchronization.

It is a block diagram which shows the structure of the communication system and transmission apparatus which concern on the 1st Embodiment of this invention. It is a wave form diagram which shows the process of an integrator. It is a wave form diagram which shows the signal waveform of the transmission signal St by a quaternary code for demonstrating a slew rate setting part. (A), (b) is a wave form diagram which shows the waveform before and after a process of a 1st signal processing means, respectively. (A), (b) is a wave form diagram which shows the waveform before a process of a 2nd signal processing means, and after a process, respectively. (A), (b) is a wave form diagram which shows the waveform before a process of a 3rd signal processing means, and after a process, respectively. (A), (b) is a wave form diagram which shows the waveform before and after a process of a 4th signal processing means, respectively. It is a block diagram which shows the structure of the communication system and receiving device which concern on the 1st Embodiment of this invention. (A)-(c) is a figure which shows the flow of a process of a transmission signal. It is a figure which shows the flow of a process of a transmission signal. It is a block diagram which shows the structure of the communication system and transmission apparatus which concern on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the communication system and receiving device which concern on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the communication system and transmission device which concern on the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the communication system and receiver which concern on the 3rd Embodiment of this invention.

Explanation of symbols

1A, 1B, 1C Transmitting device 2A, 2B Receiving device 3 Communication path 10 Communication systems 11A to 11D First to fourth signal processing means 12A to 12D First to fourth error correction units 13 Selection unit 14 Integrator 15 Through Rate setting unit 16 Identification number addition unit 17 Inversion unit 18 Specific code insertion unit 19 Multi-level conversion unit 20 1/0 counters 21A to 21D First to fourth inverse conversion means 22A to 22D First to fourth error correction units 23 selection unit 24 specific code extraction unit 25 inversion unit 26 identification number addition unit 27 integrator 28 slew rate setting unit 29 1/0 counter So output signal Ss transmission signal St transmission signal

Claims (11)

Processing means for generating a plurality of processing data by applying a plurality of types of processing to the data to be transmitted;
Processing means for performing processing for adding an error correction code to each of the plurality of processed data;
Selection means for selecting one processing data as a transmission data from a plurality of processing data processed by the processing means, and transmitting the transmission data without adding information indicating the type of processing by the processing means; A transmission apparatus comprising:   The selection unit includes a DC balance monitoring unit that monitors a DC balance of the processing data, and selects the one processing data having a good DC balance based on a monitoring result of the DC balance monitoring unit. The transmission device according to claim 1.   The selection means includes a slew rate setting unit for setting a slew rate, and selects the one processing data with a good slew rate based on the setting content of the slew rate setting unit. The transmitting device according to 1.   The selection unit includes a DC balance monitoring unit that monitors the DC balance of the previous processing data and a slew rate setting unit that sets a slew rate, and the DC balance is good based on the monitoring result of the DC balance monitoring unit. 2. The transmission apparatus according to claim 1, wherein the one processing data having a good slew rate is selected based on the setting content of the slew rate setting unit. Inverse conversion means for generating a plurality of inversely converted data by applying a plurality of types of inverse conversion to the data to which the error correction code is added;
Processing means for performing error correction processing on the plurality of inverse transform data;
A receiving apparatus comprising: selecting means for selecting one processed data as received data from a plurality of processed data processed by the processing means.   6. The receiving apparatus according to claim 5, wherein the selecting unit selects the one processed data having the lowest error rate as the received data based on an error correction code among the plurality of processed data.   The selection means includes a DC balance monitoring unit that monitors the DC balance of the processing data, and has the lowest error rate and the one processing data having a good DC balance based on the monitoring result of the DC balance monitoring unit. The receiving device according to claim 6, wherein the receiving device is selected.   The selection means includes a slew rate setting unit for setting a slew rate, and selects the one processing data with the lowest error rate and the good slew rate based on the setting contents of the slew rate setting unit. The receiving apparatus according to claim 6.   The selection unit includes a DC balance monitoring unit that monitors the DC balance of the processing data and a slew rate setting unit that sets a slew rate, and has the lowest error rate, based on the monitoring result of the DC balance monitoring unit. The receiving apparatus according to claim 6, wherein the one processing data having a good DC balance and a good slew rate is selected based on a setting content of the slew rate setting unit. The transmission device according to any one of claims 1 to 4,
A communication system comprising: the receiving device according to claim 5 connected to the transmitting device via a communication path. Multiple types of processing are performed on the data to be transmitted to generate multiple processing data,
A process of adding an error correction code to each of the plurality of processed data is performed,
One processing data is selected as transmission data from the plurality of processing data processed for the plurality of processing data,
The transmission data is transmitted without adding information indicating the type of processing,
Applying multiple types of inverse transformation to the received data received,
An error correction process is performed on the plurality of inverse transform data,
One communication data is selected as received data from a plurality of processed data processed for the plurality of inversely transformed data.

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