CN111030956A

CN111030956A - Communication method and device

Info

Publication number: CN111030956A
Application number: CN201911046203.3A
Authority: CN
Inventors: 谢志鹏; 曾焱
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-04-17
Anticipated expiration: 2039-10-30
Also published as: WO2021082699A1; CN111030956B

Abstract

The application provides a communication method and device. When the dual-band concurrent signal frame is adopted, the transmitting end can modulate the first signal frame into a first OFDM symbol sequence and modulate the part of the second signal frame except the preamble sequence into a second OFDM symbol sequence. The transmitting end may transmit the first OFDM symbol sequence through the first frequency band, and transmit the first OFDM symbol in the second OFDM symbol sequence through the second frequency band at a cut-off point where an nth OFDM symbol in the first OFDM symbol sequence is transmitted. According to the method and the device, the time domain synchronization of the second signal frame can be realized according to the first signal frame, so that the preamble symbol can be omitted in the second OFDM symbol sequence, and the transmission overhead of the second frequency band is reduced. In addition, the receiving end does not need to synchronize the second signal frame according to the preamble symbol of the second OFDM symbol sequence, so that the time delay generated by synchronizing the second signal frame is saved, and the communication rate is improved.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

In Power Line Communication (PLC), signal transmission may be performed simultaneously using two frequency bands, namely, a first frequency band and a second frequency band, so as to improve communication capacity, where a sampling rate of the first frequency band is m times of a sampling rate of the second frequency band, and m is greater than or equal to 2. For example, the first frequency band is a pass band (pass band) frequency band, and the second frequency band is a base band (base band) frequency band. Wherein the baseband may be a subcarrier transmission signal of 2 to 80 megahertz (MHz), and the passband may be a subcarrier transmission signal of 110 to 400 MHz.

In performing communication, the power line communication system may perform transmission only through the first frequency band or perform transmission of a signal frame only through the second frequency band. In addition, the power line communication system may also perform transmission of signal frames through the first frequency band and the second frequency band in a common transmission timeslot, and such a transmission mode may be referred to as dual-band concurrent communication.

In the current power line communication technology, when a power line communication system employs dual-band concurrent communication, a first frequency band signal frame and a second frequency band signal frame are independently received and transmitted, so that both an OFDM symbol sequence corresponding to the first frequency band signal frame and an OFDM symbol sequence corresponding to the second frequency band signal frame need to carry preamble symbols (preambles) for signal frame synchronization, where each preamble symbol occupies one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols. However, the preamble symbol corresponding to the second frequency band signal frame occupies too much transmission resource of the second frequency band, and the overhead is large.

Disclosure of Invention

The application provides a communication method and a communication device, which are used for reducing the problem that the overhead of a second frequency band with a lower sampling rate is larger when dual-frequency-band concurrency is adopted in a power line communication system.

In a first aspect, the present application provides a communication method, which may be implemented by a transmitting-end communication device (hereinafter, may be referred to as a transmitting end) or a chip in the transmitting end, where the transmitting end may be used for transmission of signal frames. Illustratively, the communication device may be a power line communication modem such as a power modem, or other wired or wireless communication device.

According to the method, when the dual-band concurrent signal frame is adopted, the transmitting end can modulate the first signal frame into the first OFDM symbol sequence and modulate the part of the second signal frame except the leader sequence into the second OFDM symbol sequence. The first signal frame and the second signal frame respectively include a preamble sequence, the first OFDM symbol sequence may include a plurality of OFDM symbols (hereinafter, may be simply referred to as symbols), and the second OFDM symbol sequence may include at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. When transmitting the first OFDM symbol sequence and the second OFDM symbol sequence, the transmitting end may first transmit the first OFDM symbol sequence, and transmit a first OFDM symbol in the second OFDM symbol sequence at a cut-off point of an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band.

By adopting the method, the cut-off point of the nth OFDM symbol of the first OFDM symbol sequence transmitted by the transmitting end is aligned with the starting point of the first OFDM symbol of the second OFDM symbol sequence transmitted by the transmitting end. When the receiving end synchronizes the first signal frame according to the preamble symbol in the first OFDM symbol sequence and receives the second OFDM symbol sequence from the cut-off point of receiving the nth OFDM symbol, the time domain synchronization of the second signal frame can be achieved, so that the preamble symbol can be omitted in the second OFDM symbol sequence to reduce the transmission overhead of the second frequency band. In addition, the receiving end does not need to synchronize the second signal frame according to the preamble symbol of the second OFDM symbol sequence, so that the time delay generated by synchronizing the second signal frame is saved, and the communication rate is improved.

Illustratively, the second signal frame may include a pilot signal therein. The pilot signal can be used for performing channel estimation on the frame header symbol of the second signal frame to extract the management information carried by the frame header of the second signal frame, so that the difficulty in extracting the management information caused by the fact that the second OFDM symbol sequence does not contain the preamble symbol is reduced.

Illustratively, the frame header of the first signal frame may include indication information therein. The indication information may be used to determine that the transmitting end transmitted the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. And/or the indication information may be used to determine a value of n.

By adopting the method, the receiving end can acquire the cut-off point of the transmitting end in transmitting the nth OFDM symbol in the first OFDM symbol sequence according to the indication information in the first signal frame, and transmits the first OFDM symbol in the second OFDM symbol sequence, so that the receiving end can receive the first OFDM symbol in the second OFDM symbol sequence from the cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence. In addition, when the first signal frame does not include the indication information, the receiving end determines that it is not necessary to detect the OFDM symbol sequence not including the preamble symbol in the second frequency band. Therefore, the sending end can control whether the receiving end receives the OFDM symbol sequence loaded on the second frequency band according to the communication method provided by the application, and the communication reliability and flexibility are improved.

In a specific example, when the transmitting end determines that a third OFDM symbol sequence carried in the second frequency band is detected, the transmitting end may determine the nth OFDM symbol from N OFDM symbols, where the N OFDM symbols are OFDM symbols included in the first OFDM symbol sequence, a cut-off point at which the nth OFDM symbol is transmitted does not overlap with the third OFDM symbol sequence in a time domain, N is a positive integer, and N is smaller than N. And the transmitting end can generate the indication information to indicate the value of n to the receiving end through the indication information, so that the receiving end determines the truncation point of the nth OFDM symbol of the first OFDM symbol sequence and receives the first OFDM symbol of the second OFDM symbol sequence.

By adopting the method, the second OFDM symbol sequence and the third OFDM symbol sequence can be prevented from generating time domain overlapping, the signal interference is reduced, and the transmission quality is improved.

In another specific example, when the transmitting end determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected, the transmitting end may transmit the first OFDM symbol sequence and transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the preamble symbol of the first OFDM symbol sequence.

By adopting the method, the sending end sends the first OFDM symbol in the second OFDM symbol sequence at the interception point of the preamble symbol of the first OFDM symbol sequence, so that the time domain transmission resource of the second frequency band can be utilized to the maximum extent, and the utilization rate of the transmission resource is improved.

In a second aspect, the present application provides a communication method, which may be implemented by a chip in a receiving-end communication device (hereinafter, may be simply referred to as a receiving end) or a transmitting end, where the receiving end may be used for receiving a signal frame, where the signal frame may be transmitted by the transmitting end. Illustratively, the communication device may be a power line communication modem such as a power modem, or other wired or wireless communication device.

According to the method, when dual-band concurrency is employed, a receiving end may receive a first OFDM symbol sequence transmitted through a first frequency band (e.g., a passband in power line communication) and perform synchronization of the first signal frame according to a preamble symbol included in the first OFDM symbol sequence. The first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence includes a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulation according to a first signal frame, the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band. And, the receiving end may receive the first OFDM symbol in the second OFDM symbol sequence through the second frequency band (e.g., a baseband in power line communication) at a cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

Illustratively, the second signal frame may include a pilot signal therein. The pilot signal may be used to perform channel estimation on the header symbols of the second signal frame to extract the management information carried by the header of the second signal frame.

Illustratively, the frame header of the first signal frame may include indication information. The indication information may be used to determine that the transmitting end transmitted the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. And/or the indication information may be used to determine a value of n.

In a specific example, when the receiving end determines that the third OFDM symbol sequence carried in the second frequency band is detected, the receiving end may determine the nth OFDM symbol according to the indication information, so that the first OFDM symbol of the second OFDM symbol sequence is received at a cut-off point of receiving the nth OFDM symbol of the first OFDM symbol sequence.

In another specific example, if the receiving end determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before receiving the first OFDM symbol sequence, the receiving end may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol in the first OFDM symbol sequence.

In a third aspect, the present application provides a communication apparatus, which may be a sending-end communication device or a chip in a sending-end communication device. The communication means may be adapted to perform functions or steps or operations provided in the first aspect described above or any possible design of the first aspect. The communication device may implement each function or step or operation of the above methods in the form of a hardware structure, a software module, or a hardware structure plus a software module. For example, functional modules corresponding to functions or steps or operations in the above methods may be provided in a communication device to support the communication device to execute the above methods.

When the communication device according to the third aspect is implemented by software modules, the communication device may include a communication module and a processing module, which are coupled to each other, wherein the communication module may be configured to support communication of the communication device, and the processing module may be configured to perform processing operations on the communication device, such as generating information/messages to be sent by the communication module, or processing signals received by the communication module to obtain the information/messages.

Illustratively, the processing module may be configured to modulate the first signal frame into a first OFDM symbol sequence and to modulate a portion of the second signal frame other than the preamble sequence into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. The communication module may be configured to transmit the first OFDM symbol sequence and transmit a first OFDM symbol in the second OFDM symbol sequence at a cut-off point where an nth OFDM symbol in the first OFDM symbol sequence is transmitted, where n is a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band.

Illustratively, the second signal frame includes a pilot signal.

Illustratively, the frame header of the first signal frame includes indication information. The indication information may be used to determine that the transmitting end has transmitted the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence. And/or the indication information may be used to determine a value of n.

In a specific example, when the processing module is further configured to determine that a third OFDM symbol sequence of the second frequency band is detected, the processing module is further configured to determine the nth OFDM symbol from N OFDM symbols, where the N OFDM symbols are OFDM symbols included in the first OFDM symbol sequence, a cut-off point at which the nth OFDM symbol is transmitted does not overlap with the third OFDM symbol sequence in a time domain, N is a positive integer, and N is smaller than N. And the processing module may generate the indication information, and the indication information may be used to determine a value of n.

In another specific example, when the processing module determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected, the communication module is specifically configured to transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the preamble symbol of the first OFDM symbol sequence.

When the communication device according to the third aspect is implemented by hardware components, the communication device may comprise a processor for performing the functions or steps or operations provided in the first aspect described above and/or any possible design of the first aspect. The communication device may also include a memory. Wherein the memory is operable to store instructions from which the processor is operable to invoke and execute the instructions to perform the functions or steps or operations provided in the first aspect and/or any possible design of the first aspect described above. The communication device may further include a communication interface for the communication device to communicate in a wired manner such as a power line.

Illustratively, the processor may be configured to modulate the first signal frame into a first OFDM symbol sequence and to modulate a portion of the second signal frame other than the preamble sequence into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. The communication interface may be configured to transmit a first sequence of OFDM symbols and to transmit a first OFDM symbol in a second sequence of OFDM symbols at a cut-off point where an nth OFDM symbol in the first sequence of OFDM symbols is transmitted, n being a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, when the processor is further configured to determine that a third OFDM symbol sequence of the second frequency band is detected, the processor is further configured to determine the nth OFDM symbol from N OFDM symbols, the N OFDM symbols being OFDM symbols included in the first OFDM symbol sequence, a cut-off point at which the nth OFDM symbol is transmitted not overlapping with the third OFDM symbol sequence in a time domain, N being a positive integer, N being smaller than N. And the processor may generate the indication information, and the indication information may be used to determine a value of n.

In another specific example, the communication interface is specifically operable to transmit a first OFDM symbol of the second sequence of OFDM symbols at a cut-off point where a preamble symbol of the first sequence of OFDM symbols is transmitted when the processor determines that the sequence of OFDM symbols carried in the first frequency band and the sequence of OFDM symbols carried in the second frequency band are not detected.

In a fourth aspect, the present application provides a communication apparatus, which may be a receiving-end communication device or a chip in the receiving-end communication device. The communication means may be adapted to perform the functions or steps or operations provided in the second aspect described above or any possible design of the second aspect. The communication device may implement each function or step or operation of the above methods in the form of a hardware structure, a software module, or a hardware structure plus a software module. For example, functional modules corresponding to functions or steps or operations in the above methods may be provided in a communication device to support the communication device to execute the above methods.

When the communication device of the fourth aspect is implemented by a software module, the communication device may include a communication module and a processing module, which are coupled to each other, wherein the communication module may be configured to support the communication device for communication, and the processing module may be configured to perform a processing operation on the communication device, such as generating information/message to be sent by the communication module, or processing a signal received by the communication module to obtain the information/message.

Illustratively, the communication module may be configured to receive a first sequence of OFDM symbols transmitted over a first frequency band (e.g., a passband in power line communications). The processing module may synchronize the first signal frame based on a preamble symbol included in the first sequence of OFDM symbols. The first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence includes a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulation according to a first signal frame, the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band. And the communication module may be further configured to receive the first OFDM symbol in the second OFDM symbol sequence through the second frequency band (e.g., a baseband in power line communication) at a cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

Illustratively, the second signal frame includes a pilot signal.

Illustratively, the frame header of the first signal frame may include indication information. The indication information may be used to determine that the transmitting end transmits the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence. And/or the indication information may be used to determine the value of n.

In a specific example, the indication information is used to determine a value of n, and when the processing module detects a third OFDM symbol sequence carried in the second frequency band, the processing module may determine the nth OFDM symbol according to the indication information, so that the communication module may receive the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol of the first OFDM symbol sequence.

In another specific example, if the processing module determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before the first OFDM symbol sequence is received, the communication module may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol of the first OFDM symbol sequence.

When the communication device of the fourth aspect is implemented by hardware components, the communication device may comprise a processor for performing the functions or steps or operations provided in the second aspect described above and/or any possible design of the second aspect. The communication device may also include a memory. Wherein the memory is operable to store instructions from which the processor is operable to invoke and execute the instructions to perform the functions or steps or operations provided in the second aspect described above and/or any possible design of the second aspect. The communication device may further include a communication interface for the communication device to communicate in a wired manner such as a power line.

Illustratively, the communication interface may be configured to receive a first sequence of OFDM symbols transmitted over a first frequency band (e.g., a passband in power line communications). The processor may synchronize the first signal frame based on a preamble symbol included in the first sequence of OFDM symbols. The first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence includes a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulation according to a first signal frame, the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band. And the communication interface may be further configured to receive the first OFDM symbol in the second OFDM symbol sequence via a second frequency band (e.g., a baseband in power line communication) at a cut-off point at which the nth OFDM symbol in the first OFDM symbol sequence is received, where n is a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, the indication information is used to determine a value of n, and when the processor detects a third OFDM symbol sequence carried in the second frequency band, the processor may determine the nth OFDM symbol according to the indication information, so that the communication interface may receive the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol of the first OFDM symbol sequence.

In another specific example, if the processor determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before the first OFDM symbol sequence is received, the communication interface may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol of the first OFDM symbol sequence.

In a fifth aspect, the present application provides a communication system that may include the communication apparatus shown in the third aspect and the communication apparatus shown in the fourth aspect. Wherein, the communication device shown in the third aspect may be composed of software modules and/or hardware components, and the communication device shown in the fourth aspect may be composed of software modules and/or hardware components.

Illustratively, taking the communication apparatus shown in the third aspect as a transmitting end and the communication apparatus shown in the fourth aspect as a receiving end as an example, the present application provides a communication system, in which the transmitting end may modulate a first signal frame into a first OFDM symbol sequence and modulate a portion of a second signal frame, except for a preamble sequence, into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. When transmitting the first OFDM symbol sequence and the second OFDM symbol sequence, the transmitting end may first transmit the first OFDM symbol sequence, and transmit a first OFDM symbol in the second OFDM symbol sequence at a cut-off point of an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band. Accordingly, the receiving end may receive the first OFDM symbol sequence transmitted through the first frequency band, and perform synchronization of the first signal frame according to the preamble symbol in the first OFDM symbol sequence. And the receiving end may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, n being a positive integer.

In a sixth aspect, the present application provides a computer-readable storage medium, which stores instructions (or programs) that, when executed by a computer, cause the computer to perform the method described in the first aspect or any one of the possible designs of the first aspect, or the second aspect or any one of the possible designs of the second aspect.

When carrying out the first aspect or any one of the possible designs of the first aspect as described above, the computer may modulate the first signal frame into a first OFDM symbol sequence and modulate a portion of the second signal frame other than the preamble sequence into a second OFDM symbol sequence when invoked for execution on the computer. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. And the computer may transmit, via the communication interface, the first sequence of OFDM symbols in the first frequency band and transmit the first OFDM symbol in the second sequence of OFDM symbols in the second frequency band at a cut-off point where the nth OFDM symbol in the first sequence of OFDM symbols is transmitted, n being a positive integer.

When carrying out any one of the above-mentioned second aspects or possible designs of the second aspect, when invoked to be executed on a computer, the computer may control the communication interface to receive a first OFDM symbol sequence transmitted in a first frequency band (e.g. a passband in power line communication) and to perform synchronization of the first signal frame according to a preamble symbol in the first OFDM symbol sequence, and to receive a first OFDM symbol in a second OFDM symbol sequence through a second frequency band (e.g. a baseband in power line communication) at a cut-off point of receiving an nth OFDM symbol of the first OFDM symbol sequence, n being a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

In a seventh aspect, the present application provides a computer program product, which may contain instructions, when run on a computer, cause the computer to perform the method as described in the first aspect or any one of the possible designs of the first aspect, or in the second aspect or any one of the possible designs of the second aspect.

In an eighth aspect, the present application provides a chip and/or a chip system comprising a chip, which chip may comprise a processor. The chip may also include a memory (or storage module) and/or a communication interface (or communication module). The chip may be adapted to perform the method as described in the first aspect or any one of the possible designs of the first aspect, or in the second aspect or any one of the possible designs of the second aspect. The chip system may be formed by the above chip, and may also include the above chip and other discrete devices, such as a memory (or a storage module), a communication interface and/or a communication interface (or a communication module).

Advantageous effects in the second to eighth aspects and possible designs thereof described above reference may be made to the description of advantageous effects of the method described in the first aspect and possible designs thereof.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

fig. 2 is a schematic structural flow chart of an OFDM symbol sequence corresponding to a signal frame according to an embodiment of the present disclosure;

fig. 3 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 4 is a schematic structural flow chart of another OFDM symbol sequence corresponding to a signal frame according to an embodiment of the present application;

fig. 5 is a schematic diagram of a frame header structure of a signal frame according to an embodiment of the present disclosure;

fig. 6 is a schematic diagram of a signal frame transmission timing sequence according to an embodiment of the present application;

fig. 7 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 8 is a schematic diagram of another signal frame transmission timing sequence provided in the embodiment of the present application;

fig. 9 is a flowchart illustrating another communication method according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

The communication method provided by the embodiment of the application can be used in wired or wireless communication systems such as a Power Line Communication (PLC) system or a broadband over power line (BPL) communication system, and is used for solving the problem that when the communication systems transmit signal frames through a first frequency band and a second frequency band simultaneously, the overhead of signals in the second frequency band is high.

An exemplary PLC communication system may have the architecture shown in fig. 1. As shown in fig. 1, the power line communication system may include a power line, a gateway device, a plurality of power line communication devices, and a terminal or other network-using device. The power line is used for transmitting power signals, and the voltage signals can be used for driving electric appliances. The gateway device is connected with the Internet and used for providing access to the Internet. The power line communication device may include a gateway-side power line communication device (e.g., a first power line communication device shown in fig. 1) to which the gateway-side power line communication device is connected. The power line communication device may further include a terminal-side power line communication device (e.g., a second power line communication device shown in fig. 1) for providing a network signal to a network-using device such as a terminal.

The first power line communication device may receive data transmitted from the gateway device to the terminal from the internet when transmitting the data to the terminal from the internet. The first power line communication device may also modulate data from the gateway onto the PLC signal and couple to the power line so that the data may be forwarded using the power line. The second power line communication device may be configured to demodulate a PLC signal transmitted by the power line to obtain data, and forward the data obtained after demodulation to the terminal in a wireless manner or the like, so that a network device such as the terminal receives the data from the internet side. Similarly, the system shown in fig. 1 may also implement data transmission from the terminal to the internet side.

The above power line communication device may be specifically a modem for power line communication or other types of power line communication, and the present application is not limited specifically.

At present, when data is transmitted by the first power line communication device and/or the second power line communication device as shown in fig. 1, the first power line communication device and/or the second power line communication device carries a data packet to be transmitted in a signal frame, modulates the signal into an OFDM symbol sequence, and further transmits the OFDM symbol sequence through the first frequency band signal and/or the second frequency band signal. Accordingly, after receiving the OFDM symbol sequence transmitted by the first frequency band signal and/or the second frequency band signal in the power line, the receiving-end power line communication device may obtain a signal frame through demodulation, and further may parse the data packet according to the signal frame.

As shown in fig. 2, in one possible example, the OFDM symbol sequence obtained by converting the signal frame into the time domain may include preamble symbols, header symbols, and data carrier symbols.

The preamble symbol is obtained by converting a preamble sequence (preamble) of the signal frame, and can be used for synchronization. In addition, the preamble symbol may also be used for initial channel estimation (initial channel estimation), Automatic Gain Control (AGC), and the like.

The frame header symbol may be converted from a frame header (header) of the signal frame. The frame header symbol may include some parameter information of a Physical (PHY) layer, such as an Identification (ID) of the transmitting-side power line communication device (also referred to as a Source Identification (SID)), an ID of the receiving-side power line communication device (also referred to as a Destination Identification (DID)), and the like. For example, the frame header symbol may be composed of at least one consecutive OFDM symbol.

Data carrier symbols, which may be used to carry a payload (payload) of signal frames, carry data information, such as data packets.

In some embodiments, the OFDM symbol sequence corresponding to the signal frame may further include an Additional Channel Estimation (ACE) symbol, and the additional channel estimation symbol is converted from additional channel estimation information of the signal frame. Specifically, the additional channel estimation symbol may be located between the frame header symbol and the data carrier symbol, and may be carried on at least one OFDM symbol, which is not limited in this application. The additional channel estimation symbols may be used to extract the data information carried by the data carrier symbols.

According to the communication method provided by the embodiment of the application, when the first frequency band signal frame and the second frequency band signal frame are transmitted simultaneously, the second frequency band signal frame can be synchronized through the preamble symbol of the first frequency band signal frame, so that the OFDM symbol sequence of the second frequency band signal frame may not include the preamble symbol, thereby reducing the overhead of the second frequency band communication.

The communication method provided by the embodiment of the application can be executed by the power line communication equipment (or called transmitting end) at the transmitting end and the power line communication equipment (or called receiving end) at the receiving end. As shown in fig. 3, the method may specifically include the following steps:

s101: the sending end modulates the first signal frame into a first OFDM symbol sequence and modulates the part of the second signal frame except the leader sequence into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a leader sequence, the first OFDM symbol sequence comprises a plurality of OFDM symbols, and the second OFDM symbol sequence comprises at least one OFDM symbol; the first signal frame is translated from a signal obtained at a first sampling rate over a first frequency band, the second signal frame is translated from a signal obtained at a second sampling rate over a second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer and m is greater than or equal to 2.

Illustratively, the first signal frame and the second signal frame are data signals, which are obtained by sampling and converting analog signals in a device. Wherein the first signal frame is sampled at the first sampling rate and the second signal frame is sampled at the second sampling rate. The sampling rate is used to indicate how many mega samples per second can be sampled, and the unit can be the number of mega samples per second (MSa/s). If the first frequency band is a pass band in power line communication, the first sampling rate is 200 MSa/s. If the second frequency band is a baseband in power line communication, the second sampling rate is 800 MSa/s.

When modulating the portion of the second signal frame except the preamble sequence into the second OFDM symbol sequence, the transmitting end may first identify the preamble sequence in the signal frame, discard the preamble sequence, and modulate the other portion of the second signal frame. Alternatively, the transmitting end may identify other portions of the second signal frame except for the preamble sequence and modulate the portions (or neglect to modulate the preamble sequence of the second signal frame).

S102: the transmitting end transmits the first OFDM symbol sequence and transmits the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. Or, the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence is aligned with the start point of the first OFDM symbol in the second OFDM symbol sequence (aligned means time-aligned). Or in other words, the transmitting end transmits the second OFDM symbol sequence starting from the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. It should be understood that, in the present application, the cut-off point for sending the nth OFDM symbol refers to a cut-off time for sending the nth OFDM symbol by the sending end; the starting point of transmitting the first OFDM symbol refers to a time when the transmitting end starts to transmit the first OFDM symbol.

The first OFDM symbol sequence is carried in the first frequency band (or the first OFDM symbol sequence is transmitted through the first frequency band), and the second OFDM symbol sequence is carried in the second frequency band (or the second OFDM symbol sequence is transmitted through the second frequency band).

Accordingly, the receiving end receives the first OFDM symbol sequence.

S103: and the receiving end carries out the synchronization of the first signal frame according to the preamble symbol contained in the first OFDM symbol sequence.

S104: the receiving end receives the first OFDM symbol in the second OFDM symbol sequence from the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. Or in other words, the receiving end receives the second OFDM symbol sequence starting from the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence. It should be understood that, in the present application, the cut-off point for receiving the nth OFDM symbol refers to the cut-off time for the receiving end to receive the nth OFDM symbol; the starting point of receiving the first OFDM symbol refers to the time when the receiving end starts receiving the first OFDM symbol.

The second OFDM symbol sequence does not include a preamble symbol, the first signal frame is carried in a first frequency band, the second signal frame is carried in a second frequency band, and n is a positive integer.

By adopting the above mode, the cut-off point of the n-th OFDM symbol of the first OFDM symbol sequence transmitted by the transmitting end and the start point of the first OFDM symbol of the second OFDM symbol sequence transmitted by the transmitting end are aligned. When the receiving end synchronizes the first signal frame according to the preamble symbol of the first OFDM symbol sequence and receives the second signal frame from the cut-off point of receiving the nth OFDM symbol, the time domain synchronization of the second signal frame can be achieved, so that the preamble symbol can be omitted in the second OFDM symbol sequence to reduce the transmission overhead of the second frequency band. In addition, the receiving end does not need to synchronize the second signal frame, so that the time delay generated by synchronizing the second signal frame is saved, and the communication speed is improved.

Illustratively, the above first frequency band may be a pass band in power line communication. The second frequency band may be a baseband in power line communication.

As shown in fig. 4, the second OFDM symbol sequence may include a frame header symbol and a data carrier symbol. Because the preamble symbol is not included, when carrying the same data, the length of the second OFDM symbol sequence is smaller than the length of the OFDM symbol sequence corresponding to the signal frame including the preamble symbol.

In one possible example, a header of the second signal frame may include a pilot signal (pilot tone), wherein the pilot signal may be used by the receiving end to extract the management information carried by the header. The management information may be used for receiving data carrier symbols in the second sequence of OFDM symbols and for the reception of additional channel estimation symbols if included in the second sequence of OFDM symbols.

Specifically, as shown in fig. 5, the pilot signal may be disposed at the frame header of the second signal frame at equal intervals in units of subcarriers. For example, each pilot signal may occupy one subcarrier, the interval between two adjacent pilot signals may be k subcarriers, and the remaining subcarriers not occupied by the pilot signal may be used to carry Forward Error Correction (FEC) encoded and repeated (repeat) frame header information, such as management information, where k is a positive integer. For example, k is 7.

In an implementation of the present application, the transmitting end may further indicate to the receiving end that the first OFDM symbol in the second OFDM symbol sequence is transmitted at a cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence.

In a first possible example, the indication information may be carried in a first signal frame. The indication information may be used to determine that the transmitting end transmits the first OFDM symbol of the second signal frame from a cut-off point at which the nth OFDM symbol of the first OFDM symbol sequence is transmitted. Or in other words, the indication information may be used to determine that the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence is aligned with the start point of the first OFDM symbol in the second OFDM symbol sequence. Or in other words, the indication information may be used to determine that the transmitting end transmits the second signal frame starting from a cut-off point at which the nth OFDM symbol in the first OFDM symbol sequence is transmitted. Therefore, the receiving end may receive the first OFDM symbol in the second OFDM symbol sequence from the cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence according to the indication information in the first signal frame.

Specifically, the indication information may be represented by a specific bit in the first signal frame, for example, when the specific bit in the first signal frame takes a value of 0, it indicates that the transmitting end does not transmit the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence; when the specific bit in the first signal frame is 1, it indicates that the transmitting end transmits the first OFDM symbol alignment in the second OFDM symbol sequence at the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence.

For example, when n is a fixed value, such as 1 or another value, if the receiving end parses that the frame header symbol of the first signal frame carries the indication information, the receiving end may determine to receive the 1 st OFDM symbol of the second OFDM symbol sequence from the cut-off point of receiving the 1 st OFDM symbol of the first OFDM symbol sequence. The value of n may be indicated by other information in the first signal frame or information other than the first signal frame.

With this example, the sending end may instruct the receiving end through the indication information, so as to enable the receiving end to determine whether to detect the OFDM symbol sequence not including the preamble symbol in the second frequency band (i.e., the second signal frame provided in this application), and when the first signal frame does not include the indication information, the receiving end determines that the OFDM symbol sequence not including the preamble symbol in the second frequency band is not required to be detected. At this time, the receiving end may detect the OFDM symbol sequence carrying the preamble symbol transmitted in the second frequency band, or the receiving end may synchronize the signal frame according to the preamble symbol of the signal frame transmitted in the second frequency band.

In a second possible example, the indication information may also be used to determine a value of n, so that the receiving end may determine which OFDM symbol of the first OFDM symbol sequence is being transmitted by the transmitting end, and transmit the first OFDM symbol of the second OFDM symbol sequence, so as to improve transmission reliability. For example, the indication information may indicate the value of n through a field, such as a field "001" indicating that n is 1, a field "111" indicating that n is 7, and so on.

In the above example, when the indication information is not carried in the first signal frame, the receiving end may not receive the first OFDM symbol in the second OFDM symbol sequence from the cut-off point at which the nth OFDM symbol in the first OFDM symbol sequence is received. For example, when it is determined that the indication information is not detected to be carried in the first signal frame, the receiving end may detect, according to the existing method, an OFDM symbol sequence carrying a preamble symbol transmitted in the second frequency band (for example, an OFDM symbol sequence carrying a preamble symbol carried in the second frequency band in the prior art or in a future technique), and demodulate to obtain a signal frame corresponding to the OFDM symbol sequence.

In addition, the indication information may further include: information for determining that the transmitting end transmits the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence (the specific setting manner may refer to the description of the indication information in the first possible example), and information for indicating the value of n (the specific setting manner may refer to the description of the indication information in the second possible example).

Illustratively, the indication information may be included in a header of the first signal frame. In addition, the indication information may also be sent separately from the first signal frame, for example, the sending end sends the OFDM symbol sequence corresponding to the indication information before sending the first OFDM symbol sequence.

Next, a communication method provided in an embodiment of the present application is described with reference to fig. 6 and fig. 7. In the communication method, before transmitting the first OFDM symbol sequence, as shown in fig. 6, if the transmitting end determines that it is not detected that the OFDM symbol sequence carried in the first frequency band is being transmitted in the communication medium (or, the transmitting end does not detect that the communication medium has the OFDM symbol sequence carried in the first frequency band to be transmitted), and the transmitting end determines that it is not detected that the OFDM symbol sequence carried in the second frequency band is being transmitted (or, the transmitting end does not detect that the communication medium has the OFDM symbol sequence carried in the second frequency band to be transmitted), the transmitting end may transmit the first OFDM symbol sequence and transmit the first OFDM symbol in the second OFDM symbol sequence at a cutoff point of transmitting a preamble symbol in the first OFDM symbol sequence (e.g., a first OFDM symbol in the first OFDM symbol sequence). It should be appreciated that when conducting wired and/or wireless communications, a transmitting or receiving end may detect whether there is transmission of a sequence of OFDM symbols in the current communication medium. Taking PLC communication as an example, the communication medium may refer to a power line, and the transmitting end or the receiving end may detect whether an OFDM symbol sequence is transmitted in the power line. Additionally, for wireless communications, the communication medium may be a wireless air interface.

Accordingly, before the receiving end detects the first OFDM symbol sequence transmitted in the communication medium, if the receiving end determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected, the receiving end may receive the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol in the first OFDM symbol sequence.

In addition, the header symbol of the first signal frame may carry indication information for determining that the transmitting end transmits the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the preamble symbol in the first OFDM symbol sequence. The header symbol of the first signal frame may carry the indication information. Correspondingly, when the first signal frame includes the indication information, the receiving end may also know, according to the indication information, that the first OFDM symbol in the second OFDM symbol sequence is received from the cut-off point of receiving the preamble symbol in the first OFDM symbol sequence. Furthermore, when the first signal frame does not include the indication information, the receiving end may also be configured to detect the OFDM symbol sequence of the signal frame transmitted in the second frequency band according to the prior art. Or, when the first signal frame does not include the indication information, the OFDM symbol sequence of the signal frame transmitted by the second frequency band includes a preamble symbol, and the receiving end may perform synchronization according to the preamble symbol and extract the management information in the header symbol of the OFDM symbol sequence according to the preamble symbol.

Taking the power line communication scenario shown in fig. 1 as an example, when the first power line communication device is used as a sending end of a signal frame and the second power line communication device is used as a receiving end of the signal frame, as shown in fig. 7, the communication method provided in the embodiment of the present application may include the following steps:

s201: the first power line communication device determines that the transmission of the OFDM symbol sequence carried in the pass band and the OFDM symbol sequence carried in the baseband in the power line is not detected.

S202: the first power line communication device modulates the first signal frame into a first OFDM symbol sequence, and modulates a portion of the second signal frame other than the preamble sequence into a second OFDM symbol sequence. So that the second OFDM symbol sequence does not contain preamble symbols.

The frame header of the second signal frame may include a pilot signal for extracting the management information in the frame header symbol of the second signal frame. The first signal frame is converted from a signal obtained at a first sampling rate at the pass band and the second signal frame is converted from a signal obtained at a second sampling rate at the baseband.

S203: the first power line communication device transmits a first OFDM symbol sequence, and transmits a first OFDM symbol in a second OFDM symbol sequence at a cut-off point of transmitting a preamble symbol in the first OFDM symbol sequence.

The OFDM symbol sequence of the first signal frame is carried in the passband, and the second OFDM symbol sequence is carried in the baseband.

S204: the second power line communication device receives the first OFDM symbol sequence, and determines that the OFDM symbol sequence in which the signal frame carried in the passband and the OFDM symbol sequence of the signal frame carried in the baseband are transmitted in the power line are not detected before the first OFDM symbol sequence is detected.

S205: the second power line communication device synchronizes according to the preamble symbol of the first OFDM symbol sequence and receives the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol of the first OFDM symbol sequence.

S206: and the second power line communication equipment extracts the management information in the frame header symbol of the first signal frame according to the preamble symbol in the first OFDM symbol sequence, and determines that the sending end sends the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the preamble symbol in the first OFDM symbol sequence according to the indication information contained in the management information.

The second power line communication device can perform passband channel estimation according to the preamble symbol in the first OFDM symbol sequence to obtain a passband channel equalization coefficient, and extract management information in the frame header symbol of the first signal frame according to the coefficient.

Furthermore, the second power line communication device may obtain information carried by the data carrier symbols of the first signal frame according to the management information in the frame header symbols of the first signal frame.

Specifically, the second power line communication device may receive the extra channel estimation symbol and the data carrier symbol of the first signal frame according to the management information in the frame header symbol of the first signal frame, and perform channel estimation according to the extra channel estimation symbol to obtain a channel equalization coefficient, which is used to obtain information carried by the data carrier symbol of the first signal frame.

S207: the second power line communication device obtains a frame header of the frequency domain of the second signal frame according to a frame header symbol (i.e. the first OFDM symbol, since the second OFDM symbol sequence does not include the preamble symbol, the first OFDM symbol is the frame header symbol) in the second OFDM symbol sequence.

Specifically, the second power line communication device may perform automatic power gain adjustment of the signal according to the first 1024 time domain points in the cyclic preamble of the frame header symbol in the second OFDM symbol sequence, and perform fourier transform on the first OFDM symbol of the second signal frame to obtain the frame header of the second signal frame.

S208: and the second power line communication equipment extracts the management information in the second signal frame according to the pilot signal in the frame header of the second signal frame.

For example, the second power line communication device may extract the pilot signal in the frame header of the second signal frame, and perform channel estimation by interpolation to obtain the baseband channel equalization coefficient, so as to extract the management information in the second signal frame.

S209: and the second power line communication equipment acquires the information carried by the data carrier symbol of the second signal frame according to the management information in the frame header of the second signal frame.

Specifically, the second power line communication device may receive an extra channel estimation symbol and a data carrier symbol of the second signal frame according to the management information, and perform channel estimation according to the extra channel estimation symbol to obtain a channel equalization coefficient, which is used to obtain data information carried by the data carrier symbol.

Next, with reference to fig. 8 and fig. 9, another communication method provided in the embodiment of the present application is described. In this communication method, before sending the first OFDM symbol sequence, if the sending end determines that the OFDM symbol sequence carried in the second frequency band and transmitted in the communication medium is detected (hereinafter, this OFDM symbol sequence may be referred to as a third OFDM symbol sequence), as shown in fig. 8, the sending end may carry indication information in the first signal frame. The indication information may be used to determine that the transmitting end transmits the first OFDM symbol in the second OFDM symbol sequence at a cut-off point where the nth OFDM symbol in the first OFDM symbol sequence is transmitted. The header symbol of the first signal frame may carry the indication information. And, the transmitting end may transmit the first OFDM symbol sequence and transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point where the nth OFDM symbol in the first OFDM symbol sequence is transmitted. And the cut-off point of the nth OFDM symbol is not overlapped with the third OFDM symbol sequence in a time domain. The transmitting end can also determine the nth modulation symbol from N OFDM symbols contained in the first OFDM symbol sequence, wherein N and N are positive integers, and N is more than or equal to N.

Correspondingly, when the receiving end detects the first OFDM symbol sequence carried in the first frequency band, if the receiving end determines that the communication medium further transmits the third OFDM symbol sequence carried in the second frequency band, the receiving end may determine, according to the indication information carried in the first signal frame, the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence sent by the sending end, and send the first OFDM symbol in the second OFDM symbol sequence. So that the receiving end can start receiving the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence.

Furthermore, when the first signal frame does not include the indication information, the receiving end may also be configured to detect the OFDM symbol sequence of the signal frame transmitted in the second frequency band according to the prior art. Or, when the first signal frame does not include the indication information, the OFDM symbol sequence of the signal frame transmitted in the second frequency band includes a preamble symbol, and the receiving end may perform synchronization according to the preamble symbol and extract the management information in the header symbol according to the preamble symbol.

In this example, when it is determined that there is currently transmission of the OFDM symbol sequence of the second frequency band, the transmitting end may determine whether to trigger transmission of the second OFDM symbol sequence according to the OFDM symbol sequence of the first signal frame (or, to say, whether to transmit the first OFDM symbol of the second signal frame at the cut-off point of transmitting the nth OFDM symbol of the first signal frame) according to the resource scheduling condition. For example, if the time domain resources available for transmitting the OFDM symbol sequence of the second frequency band are not sufficient for transmitting the second OFDM symbol sequence, the transmitting end may determine not to use the first signal frame to trigger the transmission of the second signal frame. For another example, if the cut-off points of all N OFDM symbols of the first signal frame are overlapped with the OFDM symbol sequence (including but not limited to the third OFDM symbol sequence) of the signal frame carried by the second frequency band in the time domain, and signal collision may be caused by transmitting the second signal frame, it may be determined that the first OFDM symbol sequence is not used to trigger the transmission of the second OFDM symbol sequence.

If the sending end determines that the sending of the second OFDM symbol sequence can be triggered according to the first OFDM symbol sequence corresponding to the first signal frame, the sending end can carry the indication information in the first signal frame, so that the receiving end determines to start receiving the second signal frame at the cut-off point of receiving the nth OFDM symbol of the first signal frame according to the indication information. Otherwise, if the sending end determines that the sending of the second OFDM symbol sequence cannot be triggered according to the OFDM symbol sequence of the first signal frame, the sending end does not carry indication information in the first signal frame, so that the receiving end determines that the receiving end does not receive the second signal frame according to the cut-off point of the nth OFDM symbol of the first signal frame, and at this time, the sending end can transmit the OFDM symbol sequence including the preamble symbol through the second frequency band, so that the receiving end detects and receives the OFDM symbol sequence carrying the preamble symbol. Or, if the transmitting end determines that the transmission of the second OFDM symbol sequence cannot be triggered according to the OFDM symbol sequence of the first signal frame, the transmitting end may carry another indication information in the first signal frame, for indicating the receiving end not to receive the second signal frame according to the cut-off point of the nth OFDM symbol of the first signal frame.

Taking the power line communication scenario shown in fig. 1 as an example, when the first power line communication device is used as a sending end of a signal frame and the second power line communication device is used as a receiving end of the signal frame, as shown in fig. 9, the communication method provided in the embodiment of the present application may include the following steps:

s301: the first powerline communication device determines that a third OFDM symbol sequence carried in the baseband is detected.

S302: the first power line communication device determines an nth OFDM symbol from the N OFDM symbols and modulates the first signal frame into a first OFDM symbol sequence and modulates a portion of the second signal frame excluding the preamble sequence into a second OFDM symbol sequence. So that the second OFDM symbol sequence does not contain preamble symbols.

The N OFDM symbols are OFDM symbols included in the first OFDM symbol sequence, and a cut-off point at which the nth OFDM symbol is transmitted does not overlap with the third OFDM symbol sequence in a time domain. The frame header symbol of the first signal frame comprises indication information used for determining that the first OFDM symbol in the second OFDM symbol sequence is sent at the cut-off point of the preamble symbol in the first OFDM symbol sequence.

In addition, the frame header of the second signal frame may include a pilot signal for extracting the management information in the frame header symbol of the second signal frame. The first signal frame is converted from a signal obtained at a first sampling rate at the pass band and the second signal frame is converted from a signal obtained at a second sampling rate at the baseband.

S303: the first power line communication device transmits a first OFDM symbol sequence, and transmits a first OFDM symbol in a second OFDM symbol sequence at a cut-off point of transmitting the nth OFDM symbol in the first OFDM symbol sequence.

S304: the second powerline communication device receives the first OFDM symbol sequence and determines that a third OFDM symbol sequence carried on the baseband is detected before receiving the first OFDM symbol sequence.

S305: the second power line communication device synchronizes according to the preamble symbol in the first OFDM symbol sequence.

S306: and the second power line communication equipment extracts the management information in the frame header symbol of the first signal frame according to the preamble symbol in the first OFDM symbol sequence, determines the cut-off point of the nth OFDM symbol in the first OFDM symbol sequence sent by the sending end according to the indication information contained in the management information, and sends the first OFDM in the second OFDM symbol sequence.

Specifically, the second powerline communication device may receive the extra channel estimation symbol and the data carrier symbol of the first signal frame according to the management information in the frame header symbol of the first signal frame, and perform channel estimation according to the extra channel estimation symbol to obtain a channel equalization coefficient for obtaining information carried by the data carrier symbol.

S307: the second power line communication device receives the first OFDM symbol in the second OFDM symbol sequence at a cut-off point at which the nth OFDM symbol in the first OFDM symbol sequence is received.

S308: and the second power line communication equipment obtains the frame header of the frequency domain of the second signal frame according to the frame header symbol in the second OFDM symbol sequence.

Specifically, the second plc device may perform automatic power gain adjustment on the signal according to the first 1024 time-domain points in the cyclic preamble of the frame header symbol (i.e., the first OFDM symbol) in the second OFDM symbol sequence, and perform fourier transform on the first OFDM symbol of the second signal frame to obtain the frame header of the second signal frame.

S309: and the second power line communication equipment extracts the management information in the second signal frame according to the pilot signal in the frame header of the second signal frame.

S310: and the second power line communication equipment acquires the information carried by the data carrier symbol of the second signal frame according to the management information in the frame header of the second signal frame.

Specifically, the second power line communication device may manage information to receive an additional channel estimation symbol and a data carrier symbol of the second signal frame, and perform channel estimation according to the additional channel estimation symbol to obtain a channel equalization coefficient for obtaining information carried by the data carrier symbol.

In the embodiments provided in the present application, the communication method and the method flow provided in the embodiments of the present application are introduced from the perspective of functions respectively implemented by the sending end and the receiving end. In order to implement each function in the method provided in the embodiment of the present application, the sending end and the receiving end may respectively include a hardware structure and/or a software module, and the functions are implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module. In the transmitting end and the receiving end, some of the above functions are executed in a hardware structure, a software module, or a hardware structure plus a software module, depending on the specific application and design constraints of the technical solution.

As shown in fig. 10, a communication apparatus 1000 according to an embodiment of the present disclosure may include a communication module 1001 and a processing module 1002, where the communication module 1001 and the processing module 1002 are coupled to each other. The communication apparatus 1000 may be configured to perform the steps performed by the transmitting end in the above method embodiments. The communication module 1001 may be used to support the communication device 1000 for communication, and the communication module 1001 may have a communication function, such as receiving and/or transmitting data frames via a wired and/or wireless communication medium, such as a power line. The processing module 1002 may be configured to support the communication apparatus 1000 to perform the processing actions of the transmitting end in the foregoing method embodiments, including but not limited to: generate information, messages, etc. sent by the communications module 1001, and/or demodulate and decode signals received by the communications module 1001, determine communications parameters from received data frames, etc.

In performing the steps performed by the power line communication device in the above method embodiments, the above processing module 1002 may be configured to modulate the first signal frame into a first OFDM symbol sequence, and modulate the portion of the second signal frame excluding the preamble sequence into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. The communication module 1001 may be configured to transmit a first OFDM symbol sequence and transmit a first OFDM symbol in a second OFDM symbol sequence at a cut-off point where an nth OFDM symbol in the first OFDM symbol sequence is transmitted, where n is a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, when the processing module 1002 may further determine that a third OFDM symbol sequence of the second frequency band is detected, the processing module 1002 may be further configured to determine the nth OFDM symbol from N OFDM symbols, where the N OFDM symbols are OFDM symbols included in the first OFDM symbol sequence, a cut-off point at which the nth OFDM symbol is transmitted does not overlap with the third OFDM symbol sequence in a time domain, N is a positive integer, and N is smaller than N. And, the processing module 1002 may generate the above indication information, which may be used to determine a value of n.

In another specific example, when the processing module 1002 determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected, the communication module 1001 is specifically configured to transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the preamble symbol of the first OFDM symbol sequence.

When the communication method provided by the present application is applied to a power line communication system, the communication device may further include a structure as shown in fig. 11, and it can be seen that the communication device 1100 may include a processor 1101, a memory 1102, and a communication interface 1103.

The processor 1101 can be used for processing communication protocols and communication data, controlling the communication device, executing software programs, processing data of the software programs, and the like. The memory 1102 may be used for storing instructions (or programs) and data, and the processor 1101 may execute the method performed by the transmitting end in the embodiment of the present application based on the instructions. The communication interface 1103 can be used in the present application for the communication device 1100 to perform wired communication, for example, receiving signals transmitted over a power line, and sending signals over the power line.

Illustratively, the above processor 1101 may be used to perform the steps performed by the processing module 1002 as described above. The communication interface 1103 may be used to perform the steps performed by the communication module 1001 described above.

In particular, the processor 1101 may be configured to modulate a first signal frame into a first OFDM symbol sequence and to modulate a portion of a second signal frame other than the preamble sequence into a second OFDM symbol sequence. The first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence can comprise a plurality of OFDM symbols, and the second OFDM symbol sequence can comprise at least one OFDM symbol. The first signal frame is converted from a signal obtained at a first sampling rate in a first frequency band (e.g., a pass band in power line communication), the second signal frame is converted from a signal obtained at a second sampling rate in a second frequency band (e.g., a baseband in power line communication), the first sampling rate is m times the second sampling rate, m is a positive integer, and m is equal to or greater than 2. Communication interface 1103 may be configured to transmit the first sequence of OFDM symbols and transmit the first OFDM symbol in the second sequence of OFDM symbols at a cutoff point where the nth OFDM symbol in the first sequence of OFDM symbols is transmitted, n being a positive integer. The first signal frame is carried in the first frequency band, and the second signal frame is carried in the second frequency band.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, when the processor 1101 can further determine that a third OFDM symbol sequence of the second frequency band is detected, the processor 1101 can be further configured to determine the nth OFDM symbol from N OFDM symbols, the N OFDM symbols being OFDM symbols included in the first OFDM symbol sequence, a cut-off point at which the nth OFDM symbol is transmitted not overlapping with the third OFDM symbol sequence in a time domain, N being a positive integer, N being smaller than N. And, the processor 1101 may generate the above-mentioned indication information, which may be used to determine the value of n.

In another specific example, when the processor 1101 determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected, the communication interface 1103 is specifically configured to transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the preamble symbol of the first OFDM symbol sequence.

It should be understood that the above communication means may also be constituted by a chip. For example, the chip contains a processor 1101. In addition, the chip may be coupled to any one or more components of memory 1102 or communication interface 1103.

As shown in fig. 12, another communication apparatus 1200 provided in an embodiment of the present application may include a communication module 1201 and a processing module 1202, where the communication module 1201 and the processing module 1202 are coupled to each other. The communication apparatus 1200 may be configured to perform the steps performed by the transmitting end in the above method embodiments. The communication module 1201 may be used to support the communication device 1200 for communication, and the communication module 1201 may have a communication function, such as receiving and/or transmitting a data frame through a wired and/or wireless communication medium, such as a power line. The processing module 1202 may be configured to support the communication apparatus 1200 to perform the processing actions of the transmitting end in the foregoing method embodiments, including but not limited to: generate information, messages, etc. sent by the communication module 1201, and/or demodulate and decode signals received by the communication module 1201, determine communication parameters from received data frames, etc.

In performing the steps performed by the power line communication device in the above method embodiments, the communication module 1201 may be configured to receive a first OFDM symbol sequence transmitted over a first frequency band (e.g., a passband in power line communication). The processing module 1202 may perform synchronization of the first signal frame according to a preamble symbol included in the first OFDM symbol sequence. The first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence includes a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulation according to a first signal frame, the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band. And, the communication module 1201 may be further configured to receive the first OFDM symbol in the second OFDM symbol sequence through the second frequency band (e.g., a baseband in power line communication) at a cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, the indication information is used to determine a value of n, and when the processing module 1202 detects a third OFDM symbol sequence carried in the second frequency band, the processing module 1202 may determine the nth OFDM symbol according to the indication information, so that the communication module 1201 may receive the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol of the first OFDM symbol sequence.

In another specific example, if the processing module 1202 determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before the first OFDM symbol sequence is received, the communication module 1201 can receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of the preamble symbol of the first OFDM symbol sequence.

When the communication method provided by the present application is applied to a power line communication system, the communication apparatus may further include a structure as shown in fig. 13. As can be seen, communications device 1300 may include a processor 1301, memory 1302, and a communications interface 1303.

The processor 1301 can be used to process communication protocols and communication data, control a communication device, execute a software program, process data of the software program, and the like. The memory 1302 may be used for storing instructions (or programs) and data, and the processor 1301 may execute the method executed by the receiving end in the embodiment of the present application based on the instructions. The communication interface 1303 can be used in the present application for the communication apparatus 1300 to perform wired communication, for example, receiving a signal transmitted through a power line, and transmitting a signal through the power line.

Illustratively, the above processor 1301 can be used to perform the steps described above as being performed by the processing module 1202. The communication interface 1303 may be used to perform the steps described above as being performed by the communication module 1201.

Specifically, the communication interface 1303 may be configured to receive a first OFDM symbol sequence transmitted over a first frequency band (e.g., a passband in power line communication). Processor 1301 may perform synchronization of the first signal frame according to a preamble symbol included in the first OFDM symbol sequence. The first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence includes a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulation according to a first signal frame, the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band. And, the communication interface 1303 is further configured to receive the first OFDM symbol in the second OFDM symbol sequence through the second frequency band (e.g., the baseband in power line communication) at the cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. Wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

Illustratively, the second signal frame includes a pilot signal.

In a specific example, the indication information is used to determine a value of n, and when the processor 1301 detects a third OFDM symbol sequence carried in the second frequency band, the processor 1301 may determine the nth OFDM symbol according to the indication information, so that the communication interface 1303 may receive the first OFDM symbol of the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol of the first OFDM symbol sequence.

In another specific example, if the processor 1301 determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before the first OFDM symbol sequence is received, the communication interface 1303 may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the preamble symbol of the first OFDM symbol sequence.

It should be understood that the above communication means may also be constituted by a chip. For example, the chip includes a processor 1301. Additionally, the chip may be coupled to any one or more components of memory 1302 or communication interface 1303.

Based on the same concept as the method embodiments, embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program causes the computer to perform the method performed by the transmitting end and/or the receiving end in any one of the possible implementations of the method embodiments and the method embodiments.

Based on the same concept as the method embodiments, the present application further provides a computer program product, which, when being invoked by a computer, enables the computer to implement the method performed by the transmitting end and/or the receiving end in any one of the possible implementation manners of the method embodiments and the method embodiments.

Based on the same concept as the method embodiments described above, the present application also provides a chip or a chip system, which may include a processor. The chip may further include or be coupled with a memory (or a storage module) and/or a communication interface (or a communication module), where the communication interface (or the communication module) may be used to support the chip to perform wired and/or wireless communication, and the memory (or the storage module) may be used to store a program, and the processor may be used to call the program to implement the method performed by the transmitting end and/or the receiving end in any one of the possible implementations of the method embodiment and the method embodiment described above. The chip system may include the above chip, and may also include the above chip and other discrete devices, such as a memory (or a storage module) and/or a communication interface (or a communication module).

Based on the same concept as the method embodiment, the application also provides a communication system which can comprise the communication device and the transmitter. The communication system may be adapted to implement the method described above in any one of the possible implementations of the method embodiments. Illustratively, the communication system may have a structure as shown in fig. 1.

The transmitting end may be configured to modulate the first signal frame into an OFDM symbol sequence including the preamble symbol, and may modulate the second signal frame into an OFDM symbol sequence not including the preamble symbol. When transmitting the OFDM symbol sequences corresponding to the first signal frame and the second signal frame, the transmitting end may first transmit the first OFDM symbol sequence, and transmit the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer. The first signal frame is carried in a first frequency band (e.g., a passband in power line communication), and the second signal frame is carried in a second frequency band (e.g., a baseband in power line communication). Accordingly, the receiving end may receive the first OFDM symbol sequence and perform synchronization of the first signal frame according to a preamble symbol included in the first OFDM symbol sequence. And the receiving end may receive the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, n being a positive integer. The transmitting end may be a first power line communication device in the power line communication system shown in fig. 1, and the receiving end may be a second power line communication device in the power line communication system shown in fig. 1. Alternatively, the transmitting end may be a second power line communication device in the power line communication system of fig. 1, and the receiving end may be a first power line communication device in the power line communication system of fig. 1.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus, and computer program products according to embodiments. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Claims

1. A method of communication, comprising:

the sending end modulates the first signal frame into a first OFDM symbol sequence and modulates the part of the second signal frame except the leader sequence into a second OFDM symbol sequence; wherein the first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence comprises a plurality of OFDM symbols, and the second OFDM symbol sequence comprises at least one OFDM symbol; the first signal frame is converted from a signal obtained at a first sampling rate over a first frequency band, the second signal frame is converted from a signal obtained at a second sampling rate over a second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer and m is greater than or equal to 2;

the sending end sends the first OFDM symbol sequence, and sends a first OFDM symbol in the second OFDM symbol sequence at a cut-off point of sending an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer, where the first OFDM symbol sequence is carried in the first frequency band, and the second OFDM symbol sequence is carried in the second frequency band.

2. The method of claim 1, wherein the second signal frame includes a pilot signal.

3. The method according to claim 1 or 2, wherein the frame header of the first signal frame includes indication information;

the indication information is used for determining that a transmitting end transmits a first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting an nth OFDM symbol in the first OFDM symbol sequence; and/or the presence of a gas in the gas,

the indication information is used for determining the value of the n.

4. The method of claim 3, wherein the method further comprises:

the sending end determines that a third OFDM symbol sequence transmitted in the second frequency band is detected;

the sending end determines the nth OFDM symbol from N OFDM symbols, wherein the N OFDM symbols are OFDM symbols contained in the first OFDM symbol sequence, a cut-off point for sending the nth OFDM symbol is not overlapped with the third OFDM symbol sequence in a time domain, N is a positive integer, and N is smaller than N;

and the sending end generates the indication information, and the indication information is used for determining the value of the n.

5. The method of any one of claims 1-3, wherein the method further comprises:

the sending end determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected;

the sending end sends the first OFDM symbol sequence and sends the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of sending the nth OFDM symbol in the first OFDM symbol sequence, including:

and the transmitting end transmits the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of the leading symbol in the first OFDM symbol sequence.

6. The method of any of claims 1-5, wherein the first frequency band comprises a pass band of power line communications and the second frequency band comprises a baseband of power line communications.

7. A method of communication, comprising:

a receiving end receives a first OFDM symbol sequence transmitted through a first frequency band, wherein the first OFDM symbol sequence is carried in the first frequency band, the first OFDM symbol sequence comprises a plurality of OFDM symbols, the first OFDM symbol sequence is obtained by modulating according to a first signal frame, the first signal frame comprises a preamble sequence, and the first signal frame is converted from a signal obtained by a first sampling rate on the first frequency band;

the receiving end carries out the synchronization of the first signal frame according to a leading symbol of the first OFDM symbol sequence, wherein the leading symbol is contained in the first OFDM symbol sequence;

the receiving end receives a first OFDM symbol in a second OFDM symbol sequence through a second frequency band at a cut-off point of an nth OFDM symbol in the first OFDM symbol sequence, wherein n is a positive integer; wherein the second OFDM symbol sequence includes at least one OFDM symbol, the second OFDM symbol sequence is modulated according to a portion of a second signal frame excluding a preamble sequence, the second signal frame includes the preamble sequence, the second signal frame is converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer, and m is greater than or equal to 2.

8. The method of claim 7, wherein a frame header of the first signal frame includes indication information;

the indication information is used for determining the value of the n.

9. The method of claim 8, wherein the indication information is used to determine a value of the n, the method further comprising:

the receiving end determines that a third OFDM symbol sequence transmitted in the second frequency band is detected;

and the receiving end determines the nth OFDM symbol according to the indication information.

10. The method of claim 7 or 8, wherein the method further comprises:

the receiving end determines that the OFDM symbol sequence carried in the first frequency band and the OFDM symbol sequence carried in the second frequency band are not detected before the first OFDM symbol sequence is received;

the receiving end receives the first OFDM symbol in the second OFDM symbol sequence through the second frequency band at the cut-off point of receiving the nth OFDM symbol in the first OFDM symbol sequence, including:

and the receiving end receives the first OFDM symbol in the second OFDM symbol sequence at the cut-off point of receiving the preamble symbol.

11. The method of any of claims 7-10, wherein the first frequency band comprises a passband of a power line communication and the second frequency band comprises a baseband of the power line communication.

12. A communication device is characterized by comprising a processing module and a communication module;

the processing module is used for modulating the first signal frame into a first OFDM symbol sequence and modulating the part of the second signal frame except the leader sequence into a second OFDM symbol sequence; wherein the first signal frame and the second signal frame respectively comprise a preamble sequence, the first OFDM symbol sequence comprises a plurality of OFDM symbols, and the second OFDM symbol sequence comprises at least one OFDM symbol; the first signal frame is converted from a signal obtained at a first sampling rate over a first frequency band, the second signal frame is converted from a signal obtained at a second sampling rate over a second frequency band, the first sampling rate is m times the second sampling rate, m is a positive integer and m is greater than or equal to 2;

the communication module is configured to send the first OFDM symbol sequence, and send a first OFDM symbol in the second OFDM symbol sequence at a cut-off point of an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer, where the first OFDM symbol sequence is carried in the first frequency band, and the second OFDM symbol sequence is carried in the second frequency band.

13. The communications apparatus of claim 12, wherein a frame header of the first signal frame includes indication information;

the indication information is used for determining the value of the n.

14. The communications apparatus of claim 13, wherein the processing module is further configured to:

determining that a third sequence of OFDM symbols transmitted in the second frequency band is detected;

determining the nth OFDM symbol from N OFDM symbols, wherein the N OFDM symbols are OFDM symbols contained in the first OFDM symbol sequence, a cut-off point for transmitting the nth OFDM symbol is not overlapped with the third OFDM symbol sequence in a time domain, N is a positive integer, and N is smaller than N;

and generating the indication information, wherein the indication information is used for determining the value of the n.

15. The communications apparatus of any of claims 12-14, wherein the processing module is further configured to:

determining that no OFDM symbol sequence carried in the first frequency band and no OFDM symbol sequence carried in the second frequency band are detected;

the communication module is specifically configured to:

and transmitting the first OFDM symbol in the second OFDM symbol sequence at a cut-off point of transmitting the preamble symbol in the first OFDM symbol sequence.

16. The communication apparatus according to any of claims 12-15, wherein the first frequency band comprises a pass band of a power line communication, and the second frequency band comprises a baseband of the power line communication.

17. A communication device is characterized by comprising a processing module and a communication module;

the communication module is configured to receive a first OFDM symbol sequence transmitted through a first frequency band, where the first OFDM symbol sequence is carried in the first frequency band, where the first OFDM symbol sequence is obtained by modulating according to a first signal frame, where the first signal frame includes a preamble sequence, and the first signal frame is converted from a signal obtained at a first sampling rate on the first frequency band;

the processing module is configured to synchronize the first signal frame according to a preamble symbol of the first OFDM symbol sequence, where the preamble symbol is included in the first OFDM symbol sequence;

the communication module is further configured to receive a first OFDM symbol in a second OFDM symbol sequence through a second frequency band at a cut-off point of receiving an nth OFDM symbol in the first OFDM symbol sequence, where n is a positive integer; the second OFDM symbol sequence is obtained by modulating a portion of a second signal frame, excluding a preamble sequence, the second signal frame including the preamble sequence, the second signal frame being converted from a signal obtained at a second sampling rate on the second frequency band, the first sampling rate being m times the second sampling rate, m being a positive integer and m being greater than or equal to 2.

18. The communications apparatus of claim 17, wherein a frame header of the first signal frame includes indication information;

the indication information is used for determining the value of the n.

19. The communications apparatus of claim 18, wherein the indication information is configured to determine a value of the n, the processing module is further configured to:

determining that a third sequence of OFDM symbols transmitted in the second frequency band is detected:

and determining the nth OFDM symbol according to the indication information.

20. The communications apparatus of claim 17 or 18, wherein the processing module is further configured to:

determining that no sequence of OFDM symbols carried in the first frequency band and no sequence of OFDM symbols carried in the second frequency band are detected before the first sequence of OFDM symbols is received;

the communication module is specifically configured to:

receiving a first OFDM symbol in the second sequence of OFDM symbols at a cut-off point where the preamble symbol is received.

21. The communication apparatus according to any of claims 17-20, wherein the first frequency band comprises a pass band of power line communication, and the second frequency band comprises a baseband of power line communication.