CN102025398B - Wired carrier communication method and device - Google Patents
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Abstract
The invention discloses a wired carrier communication method and a wired carrier communication device. A dual-mode communication method of spread-spectrum modulation technology and narrow-band modulation technology is utilized to improve the reliability and environmental adaptation of wired channel transmission and improve the critical physical layer communication capacity which limits the large-scale promotion and application of carrier communication currently. The wired carrier communication method comprises the following steps of: modulating a baseband signal by adopting a dual-mode modulation mode of spread-spectrum modulation and narrow-band modulation to obtain modulated signals of two modes; sending the modulated signals of the two modes; receiving the modulated signals of the two modes; and demodulating the modulated signals of the two modes by adopting the dual-mode modulation mode of spread-spectrum modulation and narrow-band modulation.
Description
Technical Field
The present invention relates to the field of wired communication technologies, and in particular, to a wired carrier communication method and apparatus.
Background
The current communication methods include wireless communication and wired communication, and among them, Power Line Communication (PLC) is a wired communication technology for transmitting information by using power line resources of a power system. It is also called power line carrier communication because it uses a carrier modulation technique. The method has the advantages of wide coverage range, online forever, no need of additional auxiliary lines and the like, so that the power line communication is widely applied to modern household intelligentization, broadband access and remote meter reading systems.
However, the power line channel is a special channel, and is laid for transmitting power rather than data, so that the transmission characteristics of the power line channel are often difficult to meet the requirements of data communication. For example, the power line channel has basic characteristics of high attenuation, high noise, high distortion, time-varying property, and the like, which all have great influence on communication. Therefore, power line carrier communication necessarily requires a more complex modulation and demodulation method from the beginning to overcome the above adverse effects.
Modulation techniques such as spread spectrum techniques, multi-carrier techniques, etc. all solve the inherent deficiency of power line channels for communication in some ways, but due to the complexity and diversity of power line channels, these techniques have some limitations.
Such as multi-carrier technology, the main objective is to improve the spectrum utilization and increase the transmission rate. The application based on the current power line carrier communication mainly focuses on the fields of automatic meter reading and automatic control, and the most important aim is to provide reliable and stable low-speed transmission performance, so that the spread spectrum technology is widely used in actual situations.
The spread spectrum technology is the most commonly used modulation technology in the field of power line carrier communication, and can extract signals submerged in noise through spread spectrum gain, so that the spread spectrum communication generally has extremely high sensitivity and can effectively resist high attenuation of a power line channel. Specifically, please refer to shannon (c.e. shannon) channel capacity theorem:
c-channel capacity (in terms of information transfer rate);
bandwidth of W-signal
Power of S-signal
Power of N-noise
The shannon formula shows that: when the signal transmission rate C is constant, the signal bandwidth W and the signal-to-noise ratio S/N are interchangeable, i.e. the signal bandwidth can be increased to reduce the signal-to-noise ratio. Spread spectrum communications are traded for increased signal bandwidth for signal-to-noise ratio, which is the basis for spread spectrum techniques to improve sensitivity and resistance to fading. With the increase of bandwidth, in-band noise and various interferences are also increased, especially in a noisy channel environment such as a power line channel, due to the fact that electrical appliances on a line are various, released interferences and noises are also different, besides background noises which are widely existed, various burst noises and impulse noises exist, the frequency range of the burst noises even covers the whole communication frequency band, the frequency spectrum and white noises of the noises are different absolutely, and sufficient spread spectrum gain cannot be obtained completely through a spread spectrum technology. In addition, the power line channel is also a non-linear and non-stationary communication channel, and the signal distortion becomes more serious as the signal bandwidth increases, and the resistance of the spread spectrum signal to such signal distortion is also poor. Therefore, in many cases, carrier communication using spread spectrum technology does not fully obtain its spread spectrum gain, and the actual sensitivity is much lower than the theoretical sensitivity. The simple spread spectrum technique cannot solve the problem of reliable communication of the power line channel.
In addition, at present, power line carrier communication products are still limited by physical layer communication capacity, a lot of systems need a lot of manual work to debug and install on site, one product or scheme is used well at a certain test point, but the same effect cannot be received in an individual changing environment, one product runs well at the initial stage of installation, but cases of performance reduction after running for a period of time are not enumerated, and the situations are mainly caused by the reasons that the bottom layer communication scheme is not flexible enough, the system redundancy is not enough, the robustness is poor and the like. Due to the current situation, a large amount of manpower and material resources are needed for system maintenance in the later period, the complexity and the cost of power line carrier application are increased, and the large-scale popularization and application of power line carrier communication are restricted.
Disclosure of Invention
The invention aims to provide a wired carrier communication method and a wired carrier communication device, which are used for solving the reliability problem of wired channels such as a power line channel and the like and improving the key physical layer communication capacity which restricts the large-scale popularization and application of carrier communication at present.
To solve the above technical problems, the present invention provides a wired carrier communication method, including: modulating a baseband signal by adopting a dual-mode modulation mode of spread spectrum modulation and narrow band modulation to obtain modulated signals of two modes; transmitting the modulated signals of the two modes; receiving the modulated signals of the two modes; and demodulating the modulated signals of the two modes by adopting a dual-mode modulation mode of spread spectrum modulation and narrow-band modulation.
Further, the process of transmitting the modulated signals in the two modes includes: and transmitting the modulated signals of the two modes simultaneously on two channels respectively.
Further, the process of transmitting the modulated signals in the two modes includes: and transmitting the modulated signals of the two modes in a time-sharing manner on the same channel.
Further, the transmitting the modulated signal includes: setting an auxiliary preamble signal in front of a modulated signal obtained by spread spectrum modulation; transmitting a modulated signal provided with an auxiliary preamble signal in a spread spectrum mode; the modulated signal resulting from the narrowband modulation is transmitted in a narrowband mode.
Further, the receiving the modulated signal includes: receiving in a spread spectrum mode; detecting whether an auxiliary preamble signal is received; when the auxiliary preamble signal is received, after a first preset time slot, converting a receiving mode into a narrow-band mode; and after the second preset time slot, converting the receiving mode into a spread spectrum mode.
Further, the transmitting the modulated signal includes: setting an auxiliary preamble signal in front of a modulated signal obtained by narrow-band modulation; transmitting a modulated signal provided with an auxiliary preamble signal in a narrowband mode; the modulated signal resulting from the spread spectrum modulation is transmitted in a spread spectrum mode.
Further, the receiving the modulated signal includes: receiving in a narrowband mode; detecting whether an auxiliary preamble signal is received; when the auxiliary preamble signal is received, after a third preset time slot, converting the receiving mode into a spread spectrum mode; and after the fourth preset time slot, converting the receiving mode into a narrow-band mode.
Further, the transmitting the modulated signal includes: the modulated signal obtained by the spread spectrum modulation and the narrowband modulation is transmitted alternately a plurality of times in a spread spectrum mode and a narrowband mode.
Further, the receiving the modulated signal includes: and receiving the modulated signal alternately in a spread spectrum mode and a narrow band mode in a first preset time and a second preset time respectively.
The present invention also provides a wired carrier communication apparatus, comprising: the carrier module controls the logic unit, spread spectrum modulation module, narrow band modulation module, spread spectrum demodulation module, narrow band demodulation module, sending circuit and receiving circuit, and: the spread spectrum modulation module and the narrow band modulation module are connected in parallel between the carrier module control logic unit and the sending circuit so as to respectively perform spread spectrum modulation and narrow band modulation on baseband signals; the transmitting circuit transmits modulated signals obtained by spread spectrum modulation and modulated signals obtained by narrow band modulation in a time-sharing manner; the receiving circuit is used for receiving signals, and the received signals comprise spread spectrum signals and narrowband signals; the spread spectrum demodulation module and the narrow band demodulation module are connected in parallel between the receiving circuit and the carrier module control logic unit so as to respectively carry out spread spectrum demodulation and narrow band demodulation on the received spread spectrum signal and narrow band signal.
Further, the transmission circuit includes: and the auxiliary leading signal setting module is used for setting an auxiliary leading signal in front of a modulated signal obtained by spread spectrum modulation or narrow band modulation.
Further, the receiving circuit includes: the detection module is used for detecting whether the front end of the received spread spectrum signal or narrowband signal is provided with an auxiliary preamble signal; and the switching module is connected with the detection module and realizes the switching between the spread spectrum demodulation module and the narrow-band demodulation module when the auxiliary preamble signal is detected.
Further, the receiving circuit includes: and the automatic switching module is used for alternately switching the spread spectrum demodulation module and the narrow-band demodulation module at a first preset time and a second preset time respectively.
The present invention further provides a wired carrier communication apparatus, comprising: a carrier module control logic unit; a spread spectrum transmission circuit and a narrowband transmission circuit; the spread spectrum modulation module is connected between the carrier module control logic unit and the spread spectrum sending circuit; the narrow-band modulation module is connected between the carrier module control logic unit and the narrow-band transmitting circuit; a spread spectrum receiving circuit and a narrow band receiving circuit; the spread spectrum demodulation module is connected between the spread spectrum receiving circuit and the carrier module control logic unit; and the narrow-band demodulation module is connected between the narrow-band receiving circuit and the carrier module control logic unit.
The wired carrier communication method and the device provided by the invention aim at the characteristics of low-frequency power line carrier communication and the characteristics of a power line channel, and provide a dual-mode communication method of a spread spectrum technology and a narrow band modulation technology to solve the problems of the current mainstream spread spectrum technology, so that the reliability and the environmental adaptability of wired channel transmission are enhanced, and the key physical layer communication capacity which restricts the large-scale popularization and application of carrier communication at present is improved.
Drawings
Fig. 1 is a flowchart illustrating a wired carrier communication method according to an embodiment of the present invention;
fig. 2 and fig. 3 are schematic diagrams illustrating two implementations of transmission of two modes of modulated signals in a channel, respectively;
FIGS. 4 and 5 are schematic diagrams of a preamble assisted mode synchronization method and a mode blind synchronization method without preamble assistance, respectively;
fig. 6 is a block diagram of a wired carrier communication device according to an embodiment of the present invention;
fig. 7 is a block diagram of a wired carrier communication device according to a second embodiment of the present invention;
fig. 8 and 9 are schematic diagrams of two types of power line noises, respectively.
Detailed Description
In order to make the aforementioned and other features and advantages of the invention more comprehensible, exemplary embodiments accompanied with figures are described in detail below.
As can be known from the description of the background art, the spread spectrum modulation technique has very high sensitivity and can effectively resist high attenuation of the power line channel, but the resistance of the spread spectrum signal to signal distortion is poor, and the spread spectrum signal also has poor resistance to various kinds of burst interference and impulse interference, which are common interference sources on the power line channel. For this reason, the inventors apply a narrowband modulation technique to power line communication, where the narrowband modulation technique refers to various analog or digital modulation techniques having a bandwidth much lower than a carrier frequency, such as analog FM modulation and digital ASK, PSK, FSK, and the like. After research, the narrow-band modulation technology is inferior to the spread spectrum modulation technology in the aspect of resisting random noise, but because the bandwidth is narrow, the in-band interference is less, and some single-tone interference and narrow-band interference can be easily avoided; and the ability to resist phase distortion is greatly enhanced after adopting proper modulation modes (such as PSK and FSK). Therefore, the invention provides a wired carrier dual-mode communication technology of a spread spectrum modulation technology and a narrow band modulation technology. The specific description is as follows:
please refer to fig. 1, which is a flowchart illustrating a wired carrier communication method according to an embodiment of the present invention, where the method includes the following steps:
s1: modulating a baseband signal by adopting a dual-mode modulation mode of spread spectrum modulation and narrow band modulation to obtain modulated signals of two modes;
s2: transmitting the modulated signals of the two modes;
s3: receiving the modulated signals of the two modes;
s4: and demodulating the modulated signals of the two modes by adopting a dual-mode modulation mode of spread spectrum modulation and narrow-band modulation.
It can be seen that the wired carrier communication method integrates the spread spectrum modulation technique and the narrow band modulation technique to form a carrier dual-mode communication mode, which is a mode redundancy technique, and adopts different methods to transmit the same data to achieve the purpose of reliable communication, thereby enhancing the adaptability and robustness of power line carrier transmission in various different environments. Has the following advantages: on one hand, good anti-attenuation performance is obtained through spread spectrum modulation, so that the sensitivity is guaranteed, and on the other hand, good anti-interference and anti-distortion performance is obtained through a narrow band, so that the environmental adaptability is greatly improved.
The implementation of step S2 (i.e., transmitting the modulated signals in two modes) is described in detail below. Please refer to fig. 2 and fig. 3, which show two basic implementations respectively. The first mode is as follows: as shown in fig. 2, the modulated signals of the two modes are transmitted simultaneously on two channels, respectively, and the two channels are typically tuned to different carrier frequencies to avoid the signals of the two modes interfering with each other. The method has the advantages of high efficiency, only one-time transmission of the same information, high modem overhead at the transmitting and receiving ends, and need of two independent channels to simultaneously modulate and demodulate the modulated data of two formats. The second mode is as follows: as shown in fig. 3, the two modes of modulated signals are transmitted in time-sharing manner on the same channel, and the two channels are tunable on the same carrier frequency because the two modes are separated in time. The method only requires one transmission channel, the two modulation formats are modulated and demodulated in sequence, a plurality of hardware resources can be multiplexed in the channel, the cost is low, and the cost is that twice time is required for transmitting the same information. Therefore, a person skilled in the art can select a specific dual-mode implementation method by comprehensively considering hardware overhead and transmission efficiency requirements.
In addition, when the second mode, that is, the same channel time-sharing transmission mode is selected, the transmitting end alternately transmits the modulated signal obtained by spreading and narrowband modulation, and the receiving end needs to synchronously track the mode switching operation of the transmitting end, otherwise, the mode mismatch is caused. To this end, the present invention provides two methods to achieve synchronization of the dual mode handover. One of them is to use a preamble assisted mode synchronization method; the other is a mode blind synchronization method without leading assistance. The former uses pilot frequency or other synchronous leading, and the receiving end switches the receiving channel to the next mode according to time slot after detecting leading in the current mode; the method has the advantages of high efficiency, and the dual-mode effect can be realized only by transmitting each mode once, and the method has the disadvantages that the mode synchronization depends on the reliability of preamble detection, and once the preamble is interfered, the dual-mode function is easy to fail. Another approach is blind synchronization without a preamble-assisted pattern, relying on temporal redundancy to achieve a perfect match of the patterns.
First, a specific implementation of the preamble-assisted mode synchronization method is described in detail: a transmitting end sets an auxiliary preamble signal in front of a modulated signal obtained by spread spectrum modulation; then transmitting the modulated signal provided with the auxiliary preamble signal in a spread spectrum (DS) mode; the modulated signal resulting from the narrowband modulation is then transmitted in a Narrowband (NB) mode. Correspondingly, the receiving end firstly receives in a spread spectrum (DS) mode; and detecting whether an auxiliary preamble signal is received; when the auxiliary preamble signal is received, after a first preset time slot, converting a receiving mode into a narrow-band mode; and after the second preset time slot, converting the receiving mode into a spread spectrum mode. The first preset time slot and the second preset time slot are set according to the transmission time of the modulated signals in the channels in the two modes respectively.
The above implementation is described in detail below by taking a Packet Detection (PD) preamble as an example of the secondary preamble. Please refer to fig. 4, which illustrates a preamble-assisted mode synchronization method. As shown in the figure, in the present embodiment, a Packet Detection (PD) preamble is used as an auxiliary preamble signal, and the transmitting end transmits data once per frame in a spread spectrum (DS) mode and a Narrowband (NB) mode. The detection of PD is successful and the detection of PD is failed. The receiving end of the former switches the receiving channel to NB mode for receiving after T1 time after detecting PD, and restores the receiving channel to DS mode for receiving after T2 time, thus completing a receiving process. The latter receiving end does not detect the PD, stays in the DS receiving mode all the time, and fails to achieve the effect of dual mode reception.
The above embodiment places the auxiliary preamble signal before the modulated signal modulated by spread spectrum, but the invention is not limited to this, and the auxiliary preamble signal may also be placed before the modulated signal modulated by narrow band. The specific implementation mode is as follows:
a transmitting end sets an auxiliary preamble signal in front of a modulated signal obtained by narrow-band modulation; then transmitting the modulated signal provided with the auxiliary preamble signal in a Narrowband (NB) mode; the modulated signal obtained by spread spectrum modulation is then transmitted in a spread spectrum (DS) mode. The receiving end firstly receives in a Narrow Band (NB) mode; and detecting whether an auxiliary preamble signal is received; when the auxiliary preamble signal is received, after a third preset time slot, converting the receiving mode into a spread spectrum (DS) mode; and after a fourth preset time slot, converting the receiving mode into a Narrow Band (NB) mode. Similarly, the third preset time slot and the fourth preset time slot are respectively set according to the transmission time of the two mode modulated signals in the channel. And when the auxiliary preamble signal is not detected, the receiving end stays in the NB reception mode all the time, failing to achieve the effect of dual mode reception.
In addition, when the receiving end fails to achieve the effect of dual-mode reception, the current frame may be discarded, and the transmitting end may retransmit the current frame. In addition, the detection method of the auxiliary preamble may be frequency detection and correlation detection, and the corresponding transmitting end may use a sinusoidal signal with a fixed frequency as the auxiliary preamble signal, and may also use fixed data as the auxiliary preamble signal, which is not limited in the present invention.
Secondly, a specific implementation manner of the mode blind synchronization method without preamble assistance is specifically described: the transmitting end transmits a modulated signal obtained by spread spectrum modulation and narrowband modulation alternately a plurality of times in a spread spectrum (DS) mode and a Narrowband (NB) mode. The receiving end receives the modulated signal alternately in a spread spectrum mode and a narrow band mode within a first preset time and a second preset time respectively.
Specifically, please refer to fig. 5, which shows a schematic diagram of a mode blind synchronization method without preamble assistance. As shown in the figure, each frame of data at the sending end is sent alternately in a DS mode NB mode, and the receiving end independently switches between the DS and NB receiving modes according to Ta and Tb intervals without synchronization with the sending mode switching. Generally, the number of times of sending data per frame is not less than 6, so as to ensure that the DS mode and the NB mode have at least one chance of being completely matched with the sending end, thereby achieving the effect of dual-mode transmission.
Compared with the two methods, the mode synchronization method assisted by the preamble has higher efficiency, but depends on the detection of the auxiliary preamble signal; the blind synchronization method without the pilot assistance is relatively inefficient, but does not rely on the detection of the auxiliary pilot signal. The skilled person can select as desired.
Reference is now made to the following two embodiments, which are two implementations of a wired carrier communication device provided corresponding to the above method.
The first embodiment is as follows:
please refer to fig. 6, which is a block diagram illustrating a wired carrier communication device according to an embodiment of the present invention. As shown in the figure, the wired carrier communication device includes: the carrier module comprises a carrier module control logic unit 10, a spread spectrum modulation module 22, a narrow band modulation module 24, a spread spectrum demodulation module 32, a narrow band demodulation module 34, a transmitting circuit 40 and a receiving circuit 50. Wherein, the carrier module control logic unit 10 is connected with a control interface; the spread spectrum modulation module 22 and the narrow band modulation module 24 are connected in parallel between the carrier module control logic unit 10 and the transmission circuit 40 to perform spread spectrum modulation and narrow band modulation on the baseband signal respectively; the transmission circuit 40 time-divisionally transmits the modulated signal obtained by spread spectrum modulation and the modulated signal obtained by narrow band modulation; the receiving circuit 50 is used for receiving signals, and the received signals comprise spread spectrum signals and narrow-band signals; the spread spectrum demodulation module 32 and the narrowband demodulation module 34 are connected in parallel between the receiving circuit 50 and the carrier module control logic unit 10 to perform spread spectrum demodulation and narrowband demodulation on the received spread spectrum signal and narrowband signal, respectively.
Generally, an auxiliary preamble setting module may be disposed in the transmitting circuit 40, and the auxiliary preamble is set before the modulated signal obtained by the spread spectrum modulation or the narrow band modulation. The receiving circuit 50 may be provided with a detecting module and a switching module, wherein the detecting module detects whether an auxiliary preamble signal is placed at the front end of the received spread spectrum signal or narrowband signal; the switching module is connected to the detecting module, and when the auxiliary preamble signal is detected, the switching between the spread spectrum demodulating module 32 and the narrowband demodulating module 34 is realized. In addition, an automatic switching module may be provided in the receiving circuit, instead of the above detecting module and switching module, to alternately switch the spread spectrum demodulating module 32 and the narrow band demodulating module 34 at the first preset time and the second preset time, respectively.
The spread spectrum modulation module 22 may be implemented by direct sequence spread spectrum modulation, and the narrowband modulation module 24 may be implemented by FM, ASK, FSK, and PSK, and preferably selects modulation modes such as BFSK, BPSK, QPSK, and the like.
It can be seen that the wired communication carrier apparatus in this embodiment corresponds to the second mode shown in fig. 3, that is, the modulated signals of the two modes are transmitted in a time-sharing manner on the same channel. The two modulation and demodulation modules multiplex most hardware circuits including a transceiving circuit, an analog front-end circuit and the like, so that the two modulation modes can only be selected in a time-sharing mode, and the design is a result of comprehensively considering various factors such as application requirements, implementation cost and the like.
Example two:
different from the first embodiment, the first way shown in fig. 2 is adopted, that is, modulated signals of two modes are transmitted on two channels respectively and simultaneously. Thus, their two modulation and demodulation modules require separate hardware circuitry to construct the two independent channels.
Fig. 7 is a block diagram of a wired carrier communication device according to a second embodiment of the present invention. As shown in the figure, the wired carrier communication apparatus includes a carrier module control logic unit 100, a spread spectrum modulation module 220 and a narrowband modulation module 240, a spread spectrum demodulation module 320 and a narrowband demodulation module 340, a spread spectrum transmission circuit 420 and a narrowband transmission circuit 440, a spread spectrum reception circuit 520 and a narrowband reception circuit 540. The spread spectrum modulation module 220 is connected between the carrier module control logic unit 100 and the spread spectrum transmission circuit 420; the narrowband modulation module 240 is connected between the carrier module control logic unit 100 and the narrowband transmission circuit 440; the spread spectrum demodulation module 320 is connected between the spread spectrum receiving circuit 520 and the carrier module control logic unit 100; the narrowband demodulation block 340 is connected between the narrowband receive circuit 540 and the carrier block control logic unit 100.
As can be seen from the figure, in the second embodiment, hardware circuits need to be respectively constructed for two modulation modes, namely spread spectrum modulation and narrowband modulation, so as to establish two independent channels for information transmission, which is higher in efficiency compared to the first embodiment, and the same piece of information only needs to be transmitted once, but the hardware overhead is relatively large. Those skilled in the art can select a specific configuration by considering the hardware overhead and transmission efficiency requirements.
Referring now to fig. 8 and 9, two spectral plots of power line noise are shown, the first one featuring a high, but relatively smooth, noise level that approximates random noise characteristics over a wide bandwidth. The second is characterized by a low noise level, but rich harmonics and narrow-band interference. The spread spectrum technology, the narrow-band modulation technology and the carrier dual-mode technology provided by the invention are respectively tested in the two environments, 1000 pseudo-random data frames with 30 bytes are respectively transmitted in an experiment, and the receiving frame error rate (PER) is counted, wherein:
environment 1: spread spectrum PER is 2.9 percent, narrow band PER is 16.7 percent, dual mode PER is 0.3 percent
Environment 2: spread spectrum PER is 23.3 percent, narrow band PER is 3.2 percent, dual mode PER is 0.4 percent
Tests show that although the channel environment is greatly different, the carrier dual-mode test results are relatively close, the environment consistency is relatively good, the performance is greatly improved compared with that of a single modulation technology, and the transmission reliability and the environment adaptability are greatly improved. In addition, various power line environments were tested, and similar results were obtained. Therefore, the method is also suitable for communication systems of other low-frequency (9 KHz-500 KHz) or high-frequency (more than 500KHz) wired carrier channels, including twisted pair channels, coaxial cable channels and other various wired channels.
The above description is only exemplary and not intended to limit the present invention, and the protection scope of the present invention shall be subject to the scope covered by the claims.
Claims (12)
1. A wired carrier communication method, comprising:
modulating a baseband signal by adopting a dual-mode modulation mode of spread spectrum modulation and narrow band modulation to obtain modulated signals of two modes, wherein the baseband signals are the same application data;
respectively transmitting modulated signals of the two modes on two channels with different frequencies simultaneously or transmitting the modulated signals of the two modes on the same channel in a time-sharing manner;
receiving the modulated signals of the two modes;
and demodulating the modulated signals of the two modes by adopting a dual-mode demodulation mode of spread spectrum demodulation and narrow-band demodulation.
2. The wired carrier communication method of claim 1, wherein the transmitting the modulated signal comprises:
setting an auxiliary preamble signal in front of a modulated signal obtained by spread spectrum modulation;
transmitting a modulated signal provided with an auxiliary preamble signal in a spread spectrum mode;
the modulated signal resulting from the narrowband modulation is transmitted in a narrowband mode.
3. The wired carrier communication method of claim 2, wherein the receiving the modulated signal comprises:
receiving in a spread spectrum mode;
detecting whether an auxiliary preamble signal is received;
when the auxiliary preamble signal is received, after a first preset time slot, converting a receiving mode into a narrow-band mode;
and when the auxiliary preamble signal is received, converting the receiving mode into a spread spectrum mode after a second preset time slot.
4. The wired carrier communication method of claim 1, wherein the transmitting the modulated signal comprises:
setting an auxiliary preamble signal in front of a modulated signal obtained by narrow-band modulation;
transmitting a modulated signal provided with an auxiliary preamble signal in a narrowband mode;
the modulated signal resulting from the spread spectrum modulation is transmitted in a spread spectrum mode.
5. The wired carrier communication method of claim 4, wherein the receiving the modulated signal comprises:
receiving in a narrowband mode;
detecting whether an auxiliary preamble signal is received;
when the auxiliary preamble signal is received, after a third preset time slot, converting the receiving mode into a spread spectrum mode;
and when the auxiliary preamble signal is received, converting the receiving mode into a narrow-band mode after a fourth preset time slot.
6. The wired carrier communication method of claim 1, wherein the transmitting the modulated signal comprises:
the modulated signal obtained by the spread spectrum modulation and the narrowband modulation is transmitted alternately a plurality of times in a spread spectrum mode and a narrowband mode.
7. The wired carrier communication method of claim 6, wherein the receiving the modulated signal comprises:
and receiving the modulated signal alternately in a spread spectrum mode and a narrow band mode in a first preset time and a second preset time respectively.
8. A wired carrier communication apparatus, comprising: the carrier module controls the logic unit, spread spectrum modulation module, narrow band modulation module, spread spectrum demodulation module, narrow band demodulation module, sending circuit and receiving circuit, and:
the carrier module control logic unit is used for controlling the time sequence of the time-sharing transmitting process in the transmitting path and controlling the time sequence of the time-sharing receiving process in the receiving path;
the spread spectrum modulation module and the narrow band modulation module are connected in parallel between the carrier module control logic unit and the sending circuit so as to respectively perform spread spectrum modulation and narrow band modulation on baseband signals;
the transmitting circuit transmits modulated signals obtained by spread spectrum modulation and modulated signals obtained by narrow band modulation in a time-sharing manner;
the receiving circuit is used for receiving signals, and the received signals comprise spread spectrum signals and narrowband signals;
the spread spectrum demodulation module and the narrow band demodulation module are connected in parallel between the receiving circuit and the carrier module control logic unit so as to respectively carry out spread spectrum demodulation and narrow band demodulation on the received spread spectrum signal and narrow band signal.
9. A wired carrier communication device according to claim 8, wherein the transmission circuit comprises:
and the auxiliary leading signal setting module is used for setting an auxiliary leading signal in front of a modulated signal obtained by spread spectrum modulation or narrow band modulation.
10. A wired carrier communication device according to claim 8, wherein the receiving circuit comprises:
the detection module is used for detecting whether the front end of the received spread spectrum signal or narrowband signal is provided with an auxiliary preamble signal;
and the switching module is connected with the detection module and realizes the switching between the spread spectrum demodulation module and the narrow-band demodulation module when the auxiliary preamble signal is detected.
11. A wired carrier communication device according to claim 8, wherein the receiving circuit comprises:
and the automatic switching module is used for alternately switching the spread spectrum demodulation module and the narrow-band demodulation module at a first preset time and a second preset time respectively.
12. A wired carrier communication apparatus, comprising:
the carrier module control logic unit is used for controlling the time sequence of the simultaneous transmission process in the transmission path and controlling the time sequence of the simultaneous receiving process in the receiving path;
a spread spectrum transmission circuit and a narrowband transmission circuit;
the spread spectrum modulation module is connected between the carrier module control logic unit and the spread spectrum sending circuit;
the narrow-band modulation module is connected between the carrier module control logic unit and the narrow-band transmitting circuit;
a spread spectrum receiving circuit and a narrow band receiving circuit;
the spread spectrum demodulation module is connected between the spread spectrum receiving circuit and the carrier module control logic unit;
and the narrow-band demodulation module is connected between the narrow-band receiving circuit and the carrier module control logic unit.
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| CN200910195583.7A CN102025398B (en) | 2009-09-11 | 2009-09-11 | Wired carrier communication method and device |
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| CN200910195583.7A CN102025398B (en) | 2009-09-11 | 2009-09-11 | Wired carrier communication method and device |
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| CN103117774A (en) * | 2013-01-31 | 2013-05-22 | 北京中宸泓昌科技有限公司 | Chip used for power carrier communication |
| CN103166675B (en) * | 2013-03-03 | 2016-02-17 | 北京福星晓程电子科技股份有限公司 | Power line signal based on spread spectrum detects and acquisition methods and system |
| CN103795441B (en) * | 2013-12-12 | 2016-02-03 | 青岛东软载波科技股份有限公司 | A kind of low-voltage power line carrier communication circuit based on BFSK, BPSK, DBPSK mode modulation |
| CN105225455B (en) * | 2015-10-20 | 2019-04-19 | 中北大学 | A kind of turntable wireless proximity telemetry system |
| CN107947829B (en) * | 2017-12-27 | 2023-07-25 | 上海道生物联技术有限公司 | Time division duplex communication system and method combining spread spectrum and narrowband MIMO |
| CN109274400A (en) * | 2018-10-25 | 2019-01-25 | 东莞市慧眼数字技术有限公司 | The information transferring method and system of conveying length in a kind of raising cable |
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| CN2657294Y (en) * | 2003-07-24 | 2004-11-17 | 宝山钢铁股份有限公司 | Digital voice electric power-line carrier communication device |
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| JP2001292077A (en) * | 2000-04-04 | 2001-10-19 | Osaki Electric Co Ltd | Communication method using channel occupy signal |
| EP1432099A2 (en) * | 2002-12-19 | 2004-06-23 | Panasonic Communications Co., Ltd. | Control apparatus and control method for managing communications between multiple electrical appliances through a household power line network |
| CN2657294Y (en) * | 2003-07-24 | 2004-11-17 | 宝山钢铁股份有限公司 | Digital voice electric power-line carrier communication device |
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