Carrier communication method, device and system for low-voltage power line
Disclosed in the present invention is a carrier communication method, device and system of low-voltage power lines, wherein, the carrier communication method includes: acquiring communication data comprising user data transmitted during communication and frame control data for assisting decoding of the user data; encoding the communication data using orthogonal space-time block codes and generating multipath transmission signals, in the case of unknown channel status; and transmitting the multipath transmission signals to an electric energy meter respectively via three-phase power lines. The present invention fully employs the characteristic of distinct inter-phase coupling of electrical signals at medium-and-high frequencies along power lines, and adopts various space-time encoding and decoding technologies, thereby improving the reliability of power line carrier communication between the concentrator and the electric energy meter.
1. A carrier communication method of low-voltage power lines, the method comprising:
acquiring communication data comprising user data transmitted during communication and frame control data for assisting decoding of the user data;
encoding the communication data using orthogonal space-time block codes and, in the case of unknown channel status, generating multipath transmission signals based on the encoded communication data; and
transmitting the multipath transmission signals to an electric energy meter via three-phase power lines;
wherein the multipath transmission signals are transmitted using two paths of transmission signals, and transmitting the multipath transmission signals to an electric energy meter via three-phase power lines further comprises:
transmitting one path of the multipath transmission signals to any one phase of the three-phase power lines while transmitting a second path of the multipath transmission signals simultaneously to the other two phases of the three-phase power lines.
2. The method of claim 1 , further comprising:
receiving status information of a downlink channel transmitted by the electric energy meter after an initial bidirectional link is established by a concentrator and the electric energy meter; and
encoding the communication data through weighting of one right singular value vector of a channel transfer function matrix and transmission frequency domain complex signals.
3. The method of claim 2 , wherein an encoding matrix used in encoding the communication data is:
Z spot_bf,k =V 0 *S k
wherein, Z spot_bf,k is three frequency domain complex signals respectively transmitted at three ports corresponding to sub-carrier k, S k is a post-mapping complex signal of a to-be-encoded constellation, and V 0 is a three-row one-column right singular value vector.
4. The method of claim 1 , wherein generating multipath transmission signals further comprises:
conducting fast inverse Fourier transform of the encoded multiple initial signals, and then inserting a cyclic prefix and a leading symbol to obtain the multipath transmission signal.
5. A carrier communication device for low-voltage power lines, the device comprising:
an acquisition unit configured to acquire communication data comprising user data transmitted during a communication and comprising frame control data for assisting with decoding of the user data;
a first modulation unit configured to encode the communication data using orthogonal space-time block codes and, in the case of unknown channel status, to generate multipath transmission signals based on the encoded communication data; and
a transmission unit configured to transmit the multipath transmission signals to an electric energy meter via three-phase power lines;
wherein the multipath transmission signals are transmitted using two paths of transmission signals, and the transmission unit further comprises:
a transmission module configured to transmit one path of the transmission signals to any one phase of the three-phase power lines, while transmitting a second path of the transmission signals simultaneously to the other two phases of the three-phase power lines.
6. The device of claim 5 , further comprising:
a receiving unit configured to receive status information of a downlink channel transmitted by the electric energy meter after an initial bidirectional link is established by a concentrator and the electric energy meter; and
a second modulation unit configured to encode the communication data through weighting of one right singular value vector of a channel transfer function matrix and transmission frequency domain complex signals.
7. The device of claim 5 , wherein the first modulation unit comprises:
a processing module conducting fast inverse Fourier transform of the encoded multiple initial signals, and then inserting a cyclic prefix and a leading symbol to obtain the multipath transmission signal.