JP2007006155A - Power line communication system, data transmission device and data reception device for power line communication, power line communication method, and control program of power line communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a satisfactory real-time communication quality in a power line communication system, a data transmission device and a data reception device for power line communication, a power line communication method, and the control program of the power line communication system. <P>SOLUTION: The power line communication system includes a data transmission device 5 which is connected to a power line L and transmits data by power line communication, and a data reception device 7 which receives data by power line communication. The data transmission device 5 includes a continuous transmission part 6 for changing arrangement of data to be assigned to a plurality of carrier frequencies to transmit same data continuously a plurality of times, and the data reception device 7 includes a data buffer device 11 for storing received data and a data complementing device 12 for detecting errors of previously received and recorded data and extracting correct data from next received data to complement data when detecting errors. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power line communication system that performs data communication via a power line, a data transmission device and data reception device for power line communication, a power line communication method, and a control program for the power line communication system.

  In recent years, it has been studied to perform data communication between electronic devices (electric appliances) via a power line wired in a building such as a house or a vehicle. For example, it has been studied to satisfactorily perform data communication such as an audio signal and an image signal between electronic devices such as audio devices installed in a general house using a power line in the house.

  As such a power line communication technique, for example, Patent Document 1 uses a multiple distribution line carrier communication configured to select a combination of frequencies corresponding to a control command and transmit a signal when the control command is transmitted. There has been proposed a transmission / reception apparatus. As a result, even when a power line with a lot of noise is used as a transmission line, it is intended to realize communication with a short time delay of control information transmission and excellent noise resistance.

Japanese Patent Laying-Open No. 2003-188779 (Claims, FIG. 1)

The following problems remain in the conventional technology.
In other words, with the conventional power line communication technology, when multiple electronic devices are connected and other electronic devices are operating, the impedance and noise of the power line change from moment to moment, eliminating the effects of noise and reducing signal attenuation. It is difficult to perform effectively, and there is a disadvantage that the communication quality deteriorates for a certain period of time. In particular, when communication quality deteriorates in a real-time application signal such as an audio signal or an image signal, there is a disadvantage that the reproduction reliability of sound or image is lowered. That is, there is a problem that data loss occurs, the image is disturbed, and the reproduced sound is noisy.

  The present invention has been made in view of the above-mentioned problems, and can ensure good real-time communication quality even when other electronic devices are operating, for example, even when a rapid deterioration of communication quality occurs in a short time. An object of the present invention is to provide a power line communication system, a data transmission device and a data reception device for power line communication, a power line communication method, and a control program for the power line communication system.

  The present invention employs the following configuration in order to solve the above problems. That is, the power line communication system of the present invention includes a data transmission device that is connected to a power line and transmits data by power line communication, and a data reception device that receives the data by the power line communication, and the data transmission device includes a plurality of data transmission devices. A continuous transmission means for continuously transmitting the same data a plurality of times by changing the arrangement of the data to be assigned to the carrier frequency, and the data receiving device includes a buffer means for storing the received data, Complementing means for detecting an error in the received and recorded data and extracting the correct data from the next received data and complementing the data when the error is detected. And

  A data transmission device for power line communication according to the present invention is a data transmission device that transmits data to a data reception device via a power line, and changes the arrangement of the data allocated to a plurality of carrier frequencies so that the same data Is provided with continuous transmission means for continuously transmitting a plurality of times.

  A data receiving device for power line communication of the present invention is a data receiving device that receives data from a data transmitting device via a power line, and the arrangement of the data allocated to a plurality of carrier frequencies by the data transmitting device is changed, Buffer means for receiving and storing the same data transmitted continuously a plurality of times, and detecting the error of the previously received and recorded data and receiving the next data when the error is detected Complementing means for extracting correct data from the data and complementing the data.

  The power line communication method of the present invention is the same as the power line communication method for performing power line communication between the data transmission device and the data reception device, wherein the data transmission device changes the arrangement of the data allocated to a plurality of carrier frequencies. A step of continuously transmitting the data a plurality of times, a step of storing the received data by the data receiving device, and an error of the data received and recorded by the data receiving device. A step of extracting correct data from the next received data and complementing the data when the error is detected.

  The power line communication system control program of the present invention is a power line communication system control program for performing power line communication between a data transmission device and a data reception device, wherein the data transmission device allocates the data allocated to a plurality of carrier frequencies. The same data is continuously transmitted a plurality of times, the data receiving device stores the received data, and the data receiving device previously receives and records the data And a step of causing the computer to execute a step of extracting correct data from the next received data and supplementing the data when the error is detected.

  In these power line communication systems, data transmission apparatuses and data reception apparatuses for power line communication, power line communication methods, and control programs for power line communication systems, the arrangement of data allocated to a plurality of carrier frequencies is changed, and the same data is transmitted multiple times. Continuously transmit, detect errors in the data received and recorded earlier, and when errors are detected, extract the correct data from the next received data and complement the data to prevent data loss, It is possible to prevent deterioration in communication quality such as disturbance in the image and noise in the reproduced sound.

  In the power line communication system according to the present invention, the data is an audio signal or an image signal of a real-time application, and the data transmitting device and the data receiving device have a communication speed of the audio signal or the image signal in the real-time application. On the other hand, the power line communication is performed in a transmission band in which a communication speed more than twice that is obtained. In other words, in this power line communication system, power line communication is performed in a transmission band that can obtain a communication speed more than double the communication speed of audio signals or image signals in real-time applications, so that signal buffering is stabilized by high-speed communication. Done.

The present invention has the following effects.
That is, according to the power line communication system, the data transmission device and data reception device for power line communication, the power line communication method, and the control program for the power line communication system according to the present invention, the arrangement of data allocated to a plurality of carrier frequencies is changed, By transmitting the same data continuously multiple times, detecting errors in previously received and recorded data and extracting the correct data from the next received data when an error is detected to complement the data , Stable and reliable communication quality can be maintained. Therefore, in real-time applications such as images and sounds, high-quality real-time communication can be stably obtained even when abrupt signal degradation occurs in a short time such as when an electronic device is operating.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS An embodiment of a power line communication system, a data transmission device and a data reception device for power line communication, a power line communication method, and a control program for the power line communication system according to the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the power line communication system of the present embodiment includes, for example, a power line L that is wired to a vehicle such as a general house or a bus and supplies power to a plurality of electronic devices, and data is connected to the power line L through power line communication. And a receiving-side electronic device 2 that is connected to the power line L and receives data through power-line communication.

The transmitting-side electronic device 1 is an audio device having a function of reproducing an audio signal in a real-time application, and reads out the information of the audio signal recorded on a CD-ROM, HDD or the like and reproduces it as an analog signal. A playback unit 3, an AD converter 4 that converts the reproduced audio signal into a digital signal by AD conversion, and a data transmission device 5 that transmits the data of the digitized audio signal through the power line L are provided. .
The data transmission device 5 includes a continuous transmission unit (continuous transmission unit) 6 that changes the arrangement of the data allocated to a plurality of carrier frequencies and continuously transmits the same data a plurality of times.

The receiving-side electronic device 2 is a speaker device that reproduces and outputs the received audio signal, the data receiving device 7 that receives the data of the audio signal via the power line L, and DA-converts the received data. A DA converter 8 for making an analog signal, and a speaker 9 for reproducing and outputting the analog audio signal.
The data receiving device 7 includes a receiving unit 10 for receiving the data of the audio signal via the power line L, a data buffer device (buffer means) 11 for storing the received data, and an error in the data received and recorded previously. And a data complementing device (complementing means) 12 for extracting correct data from the next received data and complementing the data when this error is detected.

  Further, the data transmission device 5 and the data reception device 7 are set to perform power line communication in a transmission band in which a communication speed more than double that of the audio signal communication speed in the real-time application can be obtained.

Note that each processing unit of data in the transmission-side electronic device 1 and the reception-side electronic device 2, that is, the audio reproduction unit 3, the AD converter 4, the continuous transmission unit 6, the reception unit 10, the data buffer device 11, the data complementing device 12, and the DA The converter 8 and the like may be realized by dedicated hardware, and each processing unit is configured by a memory and a CPU (central integrated device) as a computer system, and functions of each processing unit and a book described later. The function may be realized by loading a program for realizing the power line communication method of the embodiment into a memory and executing the program.
That is, the program is a computer-readable program, and may be for realizing a part of the functions and the power line communication method described above. Furthermore, the program may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. The transmission medium refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a power line or a telephone line.
In addition, the memory includes a non-volatile memory such as a hard disk device, a magneto-optical disk device, and a flash memory, a recording medium that can only be read such as a CD-ROM, and a volatile memory such as a RAM (Random Access Memory). Or it shall consist of a computer-readable recording medium by these combination, and a writable recording medium.

  Next, the power line communication method by the power line communication system of this embodiment is demonstrated with reference to FIGS.

First, an analog audio signal reproduced by the audio reproduction unit 3 is converted into digital signal data by the AD converter 4, and then the same data is continuously transmitted a plurality of times by the continuous transmission unit 6 of the data transmission device 5. Send through.
At this time, the continuous transmission unit 6 performs power line communication in a transmission band in which a communication speed more than double the audio signal communication speed in the real-time application can be obtained. For example, when the communication speed of an audio signal in a real-time application is 2 Mbps, communication is performed at a communication speed of 4 Mbps or more by setting the transmission band of power line communication to a band that can obtain a communication speed of 4 Mbps or more.

Moreover, the continuous transmission part 6 changes the arrangement | positioning of the said data allocated to a some carrier frequency, and transmits the same data continuously several times. For example, as shown in FIG. 2, a case will be described in which data d is divided into four data frames d _{0 to} d ₃ and these are allocated to four carrier frequencies f _{0 to} f ₃ for transmission.

First, the data d to be transmitted is divided into four data frames d _{0 to} d ₃ , and in the first transmission (t 1), the data d is divided into data frames d ₀ _ _{t 1} , d ₁ _ _{t 1} , d ₂ _ _{t 1} , transmitting assigned respectively to the carrier frequency _f 0 ~f ₃ in the order of d ₃ _ _t1. Then, in the next transmission (t2), the same data _{d d 1 _ t2, d 2} _ t2, d 3 _ t2, d 0 and relocated in the order of _ _t2 carrier frequency in the order _f 0 ~f ₃ Assign to each and send. That is, the arrangement of the data frame _d 0 to d ₃ is assigned offset one by one when the first transmission (t1) 2 nd transmission to time (t2) to each carrier frequency _f 0 ~f _3. The transmitted data d is received by the receiving unit 10 of the receiving-side electronic device 2 via the power line L and is once recorded in the data buffer device 11.

At this time, such as in operation of other electronic devices, deterioration of rapid communication quality occurs in a short time, assuming that the notch X occurs in the carrier frequency f _2, when the first transmission (t1) in, the data loss of the data frame d ₂ _ _t1 transmitted on carrier frequency f ₂ of the received data d occurs, when the second transmission (t2), the carrier frequency of the received data d f ₂ in data loss of a data frame d ₃ _ _t2 to be transmitted occurs. For this reason, if the received data d is reproduced as it is, communication quality deteriorates such as noise in the reproduced sound due to data loss.

  Therefore, the data complementing device 12 performs a data d complementing process using the data d of the first transmission (t1) and the second transmission (t2) recorded in the data buffer device 11. That is, the data complementing device 12 detects an error in the data d of the first transmission (t1) received and recorded previously, and from the data d of the second transmission (t2) received next when the error is detected. Correct data is extracted and the data d of the first transmission (t1) is complemented.

For example, the data interpolation apparatus 12, when detecting an error in data d by data loss of the data frame d ₂ _ _t1 of the first transmission (t1) at the received data d, received at the first transmission (t1) while the data frame _{d 0 _ t1, d 1 _} t1, d 2 _ t1, d 3 _ t1 to a reference, instead of the data frame _{d 2} _ _t1 of the carrier frequency _{f 2} there is data loss in time, Data d is complemented by arranging data frame d ₂ _ _t2 of carrier frequency f _{1 in} which there was no data loss during the second transmission (t2).

Thus, the first transmission (t1) than the second transmission (t2), will be both time and carrier frequency, each data frame d ₀ to d ₃ is transmitted is changed, a constant Even if a notch X or the like occurs at a carrier frequency of 1, a normal data frame can be obtained individually in either the first transmission (t1) or the second transmission (t2), and the data complementation as a whole Data d without data loss can be obtained.
Further, the complemented data d is converted into an analog signal by the DA converter 8 and reproduced and output by the speaker 9.

As described above, in the present embodiment, the arrangement of the data d allocated to the plurality of carrier frequencies f _{0 to} f ₃ is changed, the same data d is continuously transmitted a plurality of times, and the data d received and recorded first is recorded. When an error is detected and the error is detected, the correct data d is extracted from the next received data d and complemented with the data d. Therefore, rapid signal degradation occurs in a short time such as when an electronic device is operating. However, loss of data d can be prevented, and deterioration in communication quality such as disturbance in the image and noise in the reproduced sound can be prevented. Therefore, high-quality real-time communication can be stably obtained in real-time applications such as images and sounds.
In addition, since power line communication is performed in a transmission band in which a communication speed more than double the audio signal communication speed in a real-time application is obtained, signal buffering is stably performed by high-speed communication.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the above embodiment, the same data d is continuously transmitted twice from the data transmission device 5, but the same data d may be transmitted three or more times continuously. In this case, the data reception device 7 can perform data complement with higher reliability by performing the complement processing based on the data d continuously received three times or more. In this case, the data transmission device 5 and the data reception device 7 can perform better in power line communication in a transmission band that can obtain a communication speed three times higher than the communication speed of the audio signal in the real-time application. Real-time communication quality can be obtained.

  The above embodiment is applied to power line communication in a building or vehicle of a general house. For example, in the case of a vehicle, as an electronic device to be mounted, it is retrofitted via a device mounted in advance in the vehicle, a cigar socket, or the like. Any device connected to the power line L may be used. For example, devices preinstalled in the vehicle include car audio devices and car navigation devices. In addition, examples of devices that are retrofitted to the vehicle include ETC in-vehicle devices and back monitor cameras.

In the above embodiment, the audio signal is transmitted and received as data in the real-time application, but the image signal may be transmitted and received as data. In this case, the data receiving device is provided with an image display unit such as a liquid crystal display for reproducing and outputting an image signal.
Moreover, although the said embodiment demonstrated the transmission side electronic device 1 and the reception side electronic device 2 which mounted one of the data transmission device 5 and the data reception device 7, both the data transmission device 5 and the data reception device 7 are mounted. You may use the electronic device which was made.

1 is a block configuration diagram illustrating a power line communication system in a power line communication system, a data transmission device and data reception device for power line communication, a power line communication method, and a control program for the power line communication system according to an embodiment of the present invention. FIG. In this embodiment, it is explanatory drawing for demonstrating the continuous transmission of data. In this embodiment, it is explanatory drawing for demonstrating the complementary process of data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transmission side electronic device, 2 ... Reception side electronic device, 5 ... Data transmission apparatus, 6 ... Continuous transmission part (continuous transmission means), 7 ... Data reception apparatus, 11 ... Data buffer apparatus (buffer means), 12 ... Data Complementary device (complementing means), d ... data, L ... power line

Claims (6)

A data transmission device connected to the power line and transmitting data by power line communication;
A data receiving device for receiving the data by the power line communication,
The data transmission device comprises continuous transmission means for changing the arrangement of the data allocated to a plurality of carrier frequencies and continuously transmitting the same data a plurality of times,
Buffer means for storing the received data by the data receiving device;
Complementing means for detecting an error in the data received and recorded earlier and extracting correct data from the data received next when the error is detected, and complementing the data A characteristic power line communication system. The power line communication system according to claim 1,
The data is an audio signal or an image signal of a real-time application;
The power line, wherein the data transmission device and the data reception device perform the power line communication in a transmission band in which a communication speed more than double the communication speed of the audio signal or image signal in the real-time application is obtained. Communications system. A data transmission device that transmits data to a data reception device via a power line,
A data transmission apparatus for power line communication, comprising: continuous transmission means for changing the arrangement of the data allocated to a plurality of carrier frequencies and continuously transmitting the same data a plurality of times. A data receiving device for receiving data from a data transmitting device via a power line,
Buffer arrangement for receiving and storing the same data that is continuously transmitted a plurality of times by changing the arrangement of the data allocated to a plurality of carrier frequencies by the data transmission device;
Complementing means for detecting an error in the data received and recorded earlier and extracting correct data from the data received next when the error is detected, and complementing the data A data receiving device for power line communication. In a power line communication method for performing power line communication between a data transmission device and a data reception device,
The data transmission device changing the arrangement of the data allocated to a plurality of carrier frequencies and continuously transmitting the same data a plurality of times;
The data receiving device storing the received data;
The data receiving apparatus detects an error in the data received and recorded previously, and extracts the correct data from the data received next when the error is detected, and complements the data. A power line communication method comprising: In a control program for a power line communication system that performs power line communication between a data transmission device and a data reception device,
The data transmission device changing the arrangement of the data allocated to a plurality of carrier frequencies and continuously transmitting the same data a plurality of times;
The data receiving device storing the received data;
The data receiving apparatus detects an error in the data received and recorded previously, and extracts the correct data from the data received next when the error is detected, and complements the data. A control program for a power line communication system, which is executed by a computer.

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