POWER-LINE COMMUNICATION METHOD, POWER-LINE COMMUNICATION DEVICE, AND POWER-LINE COMMUNICATION SYSTEM

• US 20080304577A1
• Filed: 05/29/2008
• Published: 12/11/2008
• Est. Priority Date: 05/30/2007
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kodama, Nobutaka, KOGA, Hisao
• Granted Patent: US 8,121,202 B2
• Time in Patent Office: Days
• US Class Current: 375/257
• CPC Class Codes: H04B 2203/5416 by adding signals to the wave form of the power source
• CPC Class Codes: H04B 2203/5454 Adapter and plugs
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/203 Details of error rate determination, e.g. BER, FER or WER
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/03878 Line equalisers; line build-out devices
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

To provide a power-line communication method, a power-line communication device, and a power-line communication system, which can make communication with high communication efficiency even when the condition of a power line is changed. In step S101, a noise detection process is performed in correspondence to a time domain synchronized with a power source cycle of a power line. In step S102, a communication channel decision process of generating communication channels in the time domain is performed on the basis of the noise condition detected in step S101. In step S103, tone maps are prepared for the communication channels generated in step S102. When the preparation of the tone maps is ended, the tone maps are transmitted to a destination PLC and data are transmitted and received between a transmission-side PLC and a reception-side PLC by the use of the same tone map (step S104).

Claims

1. A power-line communication method of performing multi-carrier communication with a communication device using a power line as a communication medium, the power-line communication method comprising:

detecting a noise condition in the communication medium in correspondence to a period synchronized with a power source cycle of the power line;

generating a plurality of communication channels in a time domain in accordance with a comparison result of the noise condition with a predetermined value on the basis of the noise condition detected in the noise detection process;

preparing tone maps corresponding to the plurality of communication channels generated in the communication channel decision process; and

transmitting and receiving data on the basis of the tone maps prepared in the tone map preparation process,

wherein the communication channel decision process and the tone map preparation process are performed again after the communication process is performed.

2. The power-line communication method according to claim 1, wherein the noise detection process includes:

transmitting a packet for detecting the noise condition in the communication medium; and

detecting the noise condition on the basis of a received signal in response to the packet transmitted in the noise detection packet transmission process.

3. The power-line communication method according to claim 2, wherein the packet transmitted in the noise detection packet transmission process is transmitted in synchronization with the power source cycle.

4. The power-line communication method according to claim 1, further comprising:

detecting a variation of condition in the communication medium,

wherein when it is detected in the communication medium variation detection process that the condition in the communication medium varies more than a predetermined amount, the noise detection process, the communication channel generation process, and the tone map preparation process are performed again.

5. The power-line communication method according to claim 1, further comprising:

receiving a measurement result in the communication medium from the communication device and detecting a variation of condition in the communication medium, during communication with the communication device in the communication process,

wherein when it is detected in the communication medium condition variation detection process that the condition in the communication medium varies more than a predetermined amount, the communication channel decision process and the tone map preparation process are performed again.

6. The power-line communication method according to claim 1, further comprising:

detecting a variation of condition in the communication medium, during communication in the communication process,

wherein when it is detected in the communication medium condition variation detection process that the condition in the communication medium varies more than a predetermined amount, a transmission time of a transmission packet with respect to the power source period is changed in the communication process.

7. The power-line communication method according to claim 1, wherein the tone maps are information indicating a modulation scheme of each of a plurality of carriers used in communication using the communication media.

8. A power-line communication method of performing multi-carrier communication with a communication device using a power line as a communication medium, the power-line communication method comprising:

detecting a noise condition in the communication medium in correspondence to a period synchronized with a power source cycle of the power line;

generating a plurality of communication channels in a time domain in accordance with a comparison result of the noise condition with a predetermined value on the basis of the noise condition detected in the noise detection process;

preparing tone maps corresponding to the plurality of communication channels generated in the communication channel decision process;

transmitting and receiving data on the basis of the tone maps prepared in the tone map preparation process; and

receiving a measurement result of the communication medium from the communication device and detecting a variation in state of the communication medium, during communication with the communication device in the communication process,

wherein when it is detected in the communication medium condition variation detection process that the condition in the communication medium varies more than a predetermined amount, the communication channel decision process and the tone map preparation process are performed again.

9. A power-line communication device for performing multi-carrier communication using a power line as a communication medium, the power-line communication device comprising:

a reception section which receives a noise condition in the communication medium sent from a reception-side power-line communication device through the power line;

a transmission section which transmits a signal through the power line; and

a control section which detects the noise condition in the communication medium received by the reception section in correspondence to a time domain synchronized with a power source period of the power line, generates a plurality of communication channels in the time domain on the basis of the noise condition in the communication medium, and controls the transmission section to transmit data using tone maps corresponding to the plurality of communication channels.

10. The power-line communication device according to claim 9, wherein the transmission section transmits a packet for detecting the noise condition in the communication medium;

wherein the reception section receives the noise condition in the communication medium transmitted from a different power-line communication device which receives the packet, and

wherein the control section generates the communication channels on the basis of the condition of noise.

11. The power-line communication device according to claim 10, wherein the transmission section transmits the packet for detecting the noise condition in the communication medium in synchronization with the power source cycle.

12. The power-line communication device according to claim 9, wherein when a variation of condition in the communication medium is detected during transmission from the transmission section, the control section generates a new communication channel on the basis of a new noise condition in the communication medium and the transmission section transmits data using a tone map corresponding to the new communication channel generated by the control section.

13. The power-line communication device according to claim 9, wherein when a variation of condition in the communication medium is detected during transmission from the transmission section, the control section generates a new communication channel on the basis of the noise condition used in preparing the tone maps used for the transmission and the transmission section transmits data using a tone map corresponding to the new communication channel generated by the control section.

14. The power-line communication device according to claim 9, wherein when a variation of condition in the communication medium is detected during transmission from the transmission section, the transmission section changes the transmission time of the packet with respect to the power source cycle.

15. The power-line communication device according to claim 9, wherein the transmission section transmits a beacon to other power-line communication device connected to the power line, and

wherein the control section determines a beacon transmission time using the generated communication channels with other power-line communication devices.

16. The power-line communication device according to claim 9, wherein the control section manages communication between all the power-line communication devices connected to the power line and assigns communication bands between the power-line communication devices on the basis of the communication channels between all the power-line communication devices.

17. The power-line communication device according to claim 9, wherein the tone maps are information indicating a modulation manner of each of a plurality of carriers used in communication using the communication channels.

18. A power-line communication device for performing multi-carrier communication using a power line as a communication medium, the power-line communication device comprising:

a reception section which receives a signal from the power line;

a transmission section which transmits a noise condition in the communication medium to a transmission-side power-line communication devices through the power line; and

a control section which detects the noise condition in the communication medium in correspondence to a time domain synchronized with a power source cycle of the power line on the basis of the signal received by the reception section, prepares tone maps corresponding to each of a plurality of communication channels in the time domain generated by the transmission-side power-line communication device on the basis of the noise condition, and controls the reception section to receive data using the prepared tone maps.

19. The power-line communication device according to claim 18, wherein the control section detects the noise condition on the basis of a reception state of a noise detection packet in the reception section from a different power-line communication device.

20. The power-line communication device according to claim 18, wherein the control section stores the tone maps received from the different power-line communication device.

21. The power-line communication device according to claim 18, wherein the control section detects the noise condition using at least one of a carrier power to interference power plus noise power ratio of a signal transmitted through the communication medium, the carrier power to the noise power ratio of the signal, an error rate of transmission data, the number of re-transmission or a re-transmission rate of the transmission data, and an error rate of the transmission data.

22. The power-line communication device according to claim 18, wherein the control section detects the noise condition in the communication medium in the unit of slots synchronized with the power source period of the power line.

23. The power-line communication device according to claim 18, wherein the tone maps are information indicating a modulation scheme of each of a plurality of carriers used in communication using the communication channels.

24. A power-line communication system for performing multi-carrier communication using a power line as a communication medium, the power-line communication system comprising:

a first power-line communication device including;

a reception section which receives a noise condition in the communication medium sent from a reception-side power-line communication device through the power line;

a transmission section which transmits a signal through the power line; and

a control section which detects the noise condition in the communication medium received by the reception section in correspondence to a time domain synchronized with a power source cycle of the power line, generates a plurality of communication channels in the time domain on the basis of the noise condition in the communication medium, and controls the transmission section to transmit data using tone maps corresponding to the plurality of communication channels; and

a second power-line communication device including;

a reception section which receives a signal from the power line;

a transmission section which transmits a noise condition in the communication medium to a transmission-side power-line communication device through the power line; and

a control section which detects the noise condition in the communication medium in correspondence to a time domain synchronized with a power source cycle of the power line on the basis of the signal received by the reception section, prepares tone maps corresponding to each of a plurality of communication channels in the time domain generated by the transmission-side power-line communication device on the basis of the noise condition, and controls the reception section to receive data using the prepared tone maps.

25. An integrated circuit used for multi-carrier communication using a power line as a communication medium, the integrated circuit comprising:

a noise detection section connected to a coupler interfacing with the power line so as to detect a noise condition in the communication medium through the coupler in correspondence to a time domain synchronized with a power source cycle of the power line;

a tone map preparation section which prepares tone maps corresponding to communication channels in the time domain generated on the basis of the noise condition; and

a communication control section which controls a communication section to transmit and receive data using the tone maps prepared by the tone map preparation section.

26. A circuit module used for multi-carrier communication using a power line as a communication medium, the circuit module comprising:

a coupler which interfaces with the power line; and

a control section which detects a noise condition in the communication medium through the coupler in correspondence to a time domain synchronized with a power source cycle of the power line, prepares tone maps corresponding to communication channels in the time domain generated on the basis of the noise condition, and controls a communication section to transmit and receive data using the prepared tone maps.