Power line carrier modulation method, device and system for carrier chip

Abstract

The invention relates to the technical field of communication signal transmission, in particular to a power line carrier modulation method, device and system for a carrier chip, and the method comprises the steps: obtaining historical communication signals of each time period of each user node transmitted through a power line in the previous day of the current day; obtaining a standard modulation signal of each time period of each user node; extracting a noise time domain signal, and obtaining a noise spectrogram of each time period of each user node; determining the noise difference degree of each time period between each user node and each other user node; determining the channel overlap ratio of each user node and other user nodes; extracting a colored noise signal of each user node; and determining the optimal carrier frequency of each user node on the same day, and carrying out carrier communication on communication signals of the user nodes. According to the invention, noise interference on power line carrier communication can be effectively reduced, and communication transmission errors are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of communication signal transmission, and in particular to a power line carrier modulation method, device and system for a carrier chip. Background Art

[0002] A carrier chip is a communication chip that can mix baseband signals and carrier signals to generate modulated signals. Power line carrier communication (PLC) is a communication method that uses AC current as a carrier signal and power cables as channels. When a carrier chip is used in the field of power line carrier modulation, it can be used to transmit power consumption information on the user side, making it easier for the power grid to collect power consumption information from users in real time.

[0003] When transmitting modulated signals through power lines, there is a lot of noise in the power cables. The noise includes not only white noise, but also colored noise from various electrical appliances, which will interfere with the communication of PLC. Colored noise usually has a fixed frequency range and causes great interference to the communication signal, affecting the communication effect. Therefore, when obtaining the modulated signal, it is necessary to select a suitable carrier frequency and avoid the frequency range with large interference to ensure that there will be no communication errors. Therefore, when modulating the power line carrier, there is a problem of serious interference of the modulated signal caused by improper selection of the carrier frequency, which leads to information transmission errors. Summary of the invention

[0004] In order to solve the above technical problems, a power line carrier modulation method, device and system for a carrier chip are provided to overcome the existing deficiencies.

[0005] In a first aspect, the present application provides a power line carrier modulation method and system for a carrier chip, comprising the following steps:

[0006] Obtain historical communication signals of multiple user nodes in each time period after being transmitted via the power line the day before the current day;

[0007] Based on the historical communication signal, a standard modulation signal of each user node in each time period is obtained through a demodulation and modulation process; and the difference between the historical communication signal and the standard modulation signal is analyzed, the noise time domain signal is extracted, and a noise spectrum diagram of each user node in each time period is obtained;

[0008] Determine the noise difference between each user node and the other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes; and determine the channel overlap between each user node and the other user nodes based on the noise difference;

[0009] Based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes and the channel overlap, the colored noise signal of each user node is extracted; and based on the colored noise signal, the optimal carrier frequency of each user node on that day is determined, and carrier communication is performed on the communication signal of each user node.

[0010] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, obtaining the standard modulation signal of each user node in each time period through a demodulation and modulation process based on the historical communication signal includes:

[0011] Based on the carrier frequency of each user node when performing power line communication on the historical communication signal on the day before the current day, a signal demodulation algorithm is used to obtain a digital bit stream corresponding to the historical communication signal of each user node in each time period;

[0012] A signal modulation algorithm is used to modulate the digital bit stream of each user node in each time period to obtain a standard modulation signal of each user node in each time period.

[0013] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, the analyzing the difference between the historical communication signal and the standard modulation signal to extract the noise time domain signal includes:

[0014] The difference between the historical communication signal of each user node in each time period and the standard modulation signal of the corresponding time period is used as the noise time domain signal of each user node in each time period.

[0015] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, the step of obtaining a noise spectrum diagram of each user node in each time period includes:

[0016] A frequency domain analysis algorithm is used to draw a noise spectrum diagram of the noise time domain signal of each user node in each time period.

[0017] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, determining the noise difference between each user node and the remaining user nodes in each time period according to the difference in the noise spectrum diagrams in the same time period between different user nodes includes:

[0018] All energy amplitudes in the noise spectrum graph are used to form a noise frequency domain vector for each user node in each time period;

[0019] The difference degree of the noise frequency domain vector between each user node and the other user nodes in the same time period is used as the noise difference degree between each user node and the other user nodes in each time period.

[0020] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, determining the channel overlap between each of the user nodes and the remaining user nodes based on the noise difference includes:

[0021] Calculate the discrete degree and mean value of the noise difference between each user node and the other user nodes in all time periods respectively;

[0022] The inverse of the product of the discrete degree and the mean value is used as the channel overlap degree between each of the user nodes and the remaining user nodes.

[0023] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, the colored noise signal is calculated as follows:

[0024]

[0025] Among them, U n is the colored noise signal of the nth user node, α n,m is the channel overlap between the nth user node and the mth user node, V n,h is the noise frequency domain vector of the hth time period of the nth user node, N is the number of all user nodes, and H is the number of all time periods.

[0026] Optionally, in the above-mentioned power line carrier modulation method for a carrier chip, determining the optimal carrier frequency of each user node based on the colored noise signal and performing carrier communication transmission on the communication information of the user node includes:

[0027] The frequency corresponding to the minimum element value in the colored noise signal of each user node in the noise spectrum diagram is used as the optimal carrier frequency of each user node on that day;

[0028] Based on the optimal carrier frequency, a signal modulation algorithm is used to modulate the digital bit stream of each user node on that day, and a modulated signal is output. After the modulated signal is sent to the power line for transmission, a signal demodulation algorithm is used to output it as a digital bit stream.

[0029] In a second aspect, the present application further provides a power line carrier modulation device for a carrier chip, the device comprising:

[0030] An acquisition unit, used for acquiring historical communication signals of multiple user nodes in each time period after being transmitted via the power line the day before the current day;

[0031] A first modulation unit is used to obtain a standard modulation signal of each user node in each time period through a demodulation and modulation process based on the historical communication signal; and analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time domain signal, and obtain a noise spectrum diagram of each user node in each time period;

[0032] A second modulation unit is used to determine the noise difference between each user node and the other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes; and determine the channel overlap between each user node and the other user nodes based on the noise difference;

[0033] The third modulation unit is used to extract the colored noise signal of each user node based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes and the channel overlap; and based on the colored noise signal, determine the optimal carrier frequency of each user node on that day, and perform carrier communication on the communication signal of each user node.

[0034] In a third aspect, the present application also provides a power line carrier modulation system for a carrier chip, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that when the processor executes the computer program, it implements the steps of the power line carrier modulation method for a carrier chip as described in any of the above.

[0035] This application has at least the following beneficial effects:

[0036] The present application is based on the historical communication signal of the user node, and obtains the standard modulation signal of each user node in each time period through the demodulation and modulation process. The standard modulation signal is a communication signal that does not contain noise in the communication channel, so as to extract the noise signal later; analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time domain signal, and obtain the noise spectrum diagram of each user node in each time period. This step takes into account the interference of channel noise during signal transmission, and extracts the noise signal to perform frequency domain analysis on it; according to the difference of the noise spectrum diagram of the same time period between different user nodes, determine the noise difference degree between each user node and the other user nodes in each time period; based on ... The degree of sound difference is used to determine the channel overlap between each user node and the other user nodes. Since the differences in the influence of noise in the channel when transmitting signals between different user nodes are taken into account, it reflects the overlap of the channels when different user nodes transmit signals, and further indicates that the two user nodes can use the same carrier frequency for signal modulation; based on the noise spectrum diagram of all time periods between each user node and the other user nodes, combined with the channel overlap, the colored noise signal of each user node is extracted, and the random white noise in the noise time domain signal is eliminated to extract the colored noise signal; based on the colored noise signal, the optimal carrier frequency of each user node on the day is determined, and the communication signal of the user node is carried out as a carrier communication. The present application can effectively reduce the noise interference on power line carrier communication and avoid errors in communication transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The power line carrier modulation method for a carrier chip of the present application is further described in detail below with reference to the accompanying drawings.

[0038] Figure 1 A schematic flow chart of a power line carrier modulation method for a carrier chip provided in one embodiment of the present application;

[0039] Figure 2 A schematic diagram of historical communication signals of each user node in each time period provided for one embodiment of the present application;

[0040] Figure 3 A visual schematic diagram of a digital bit stream corresponding to a historical communication signal provided by one embodiment of the present application;

[0041] Figure 4 A schematic diagram of a standard modulation signal for each user node in each time period provided for an embodiment of the present application;

[0042] Figure 5 A schematic flow chart of a method for obtaining a noise spectrum diagram of each user node in each time period provided by an embodiment of the present application;

[0043] Figure 6A schematic flow chart of a method for obtaining the channel overlap between each user node and other user nodes provided in an embodiment of the present application;

[0044] Figure 7 A schematic structural diagram of a power line carrier modulation device for a carrier chip according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clear, the power line carrier modulation method and system for the carrier chip proposed in the present application are further described in detail below in conjunction with the accompanying drawings and implementation examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0047] See also Figure 1 , which shows a schematic flow chart of a power line carrier modulation method for a carrier chip provided by an embodiment of the present application, and this embodiment includes steps S110 to S140:

[0048] Step S110, obtaining the historical communication signals of each user node in each time period after being transmitted via the power line the day before the current day.

[0049] The power line carrier communication (PLC) system encodes, modulates, and couples the original communication data to convert it into a signal that can be transmitted on the power line. After transmission through the power line, the original communication data is obtained through signal coupling, demodulation, and decoding, thereby completing the transmission of the carrier signal.

[0050] Since the power lines are subject to different grid loads and interference at different times of the day, the transmission quality of the PLC signal may be affected. Therefore, the communication data of the previous day of each user node is obtained from the grid control center. The communication data refers to the modulated signal from the user received by the grid control center, which is a communication signal with noise after the modulated signal is transmitted through the power line. The time interval t is collected to obtain the historical communication data of each time period, wherein the storage form of the historical communication data of each time period is a vector, and the kth element in the vector represents the signal strength of the modulated signal sent by the user at time k. Therefore, the historical communication data of each time period is recorded as the historical communication signal of each user node in each time period.

[0051] Preferably, in some embodiments of the present application, the time interval t is 10 minutes, and the historical communication data of each time period is obtained every 10 minutes. It should be noted that if every 10 minutes is regarded as a time period, then a total of 144 time periods of communication data are collected in the day before the current day; secondly, since the frequency of power line carrier communication is usually between 50k and 450k Hz, according to the Nyquist sampling theorem, the sampling frequency is at least twice the signal frequency. Therefore, the sampling frequency of the historical communication data is 900k Hz, and the vector length is 540 MHz.

[0052] For further information, please refer to Figure 2 , Figure 2 FIG. 1 shows a schematic diagram of historical communication signals of each user node in each time period provided by an embodiment of the present application, such as Figure 2 As shown, the horizontal axis represents the sampling order, and the vertical axis represents the signal amplitude. Figure 2 It can be clearly observed that the historical communication signals are interfered by various noises.

[0053] So far, the historical communication signals of each user node in each time period on the day before the current day have been obtained.

[0054] Step S120, based on the historical communication signal, obtain the standard modulation signal of each user node in each time period through demodulation and modulation process; and analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time domain signal, and obtain the noise spectrum diagram of each user node in each time period.

[0055] For historical communication signals, the transmitted digital information contains information about the noise to which the communication data is subject. Therefore, it is necessary to extract the noise information from it and avoid the frequency domain where the noise is more concentrated when determining the carrier frequency to avoid information transmission errors.

[0056] For historical communication signals, a signal demodulation method is used to obtain the bit information hidden therein, including:

[0057] Based on the carrier frequency of each user node when performing power line communication on the historical communication signal on the day before the current day, a signal demodulation algorithm is used to obtain the digital bit stream corresponding to the historical communication signal of each user node in each time period.

[0058] In some embodiments of the present application, the signal demodulation algorithm may be any one of the existing technologies, which will not be repeated here; secondly, the carrier frequency in the signal demodulation algorithm is the carrier frequency of the previous day, and the signal modulation method is ASK amplitude shift keying; wherein, the obtained digital bit stream is the information that the user needs to transmit.

[0059] It should be noted that when the user performs PLC communication on the first day, a fixed frequency is used as the carrier frequency. Starting from the second day, the optimal carrier frequency of the day is calculated by the historical communication signal of the previous day as the carrier frequency of the day. In some embodiments of the present application, the fixed frequency is 250k Hz.

[0060] further, Figure 3 FIG. 1 shows a visualization diagram of a digital bit stream corresponding to a historical communication signal provided by an embodiment of the present application, such as Figure 3 As shown, the horizontal axis represents the sampling order and the vertical axis represents the signal amplitude.

[0061] Further, the digital bit stream is modulated to obtain a standard modulation signal without noise, specifically including:

[0062] Using a signal modulation algorithm, modulate the digital bit stream of each user node in each time period to obtain a standard modulation signal of each user node in each time period;

[0063] In some embodiments of the present application, the signal modulation algorithm may be any one of the prior art, which will not be described in detail here; the carrier frequency in the signal modulation algorithm is the carrier frequency of the previous day, and the signal modulation method is ASK amplitude shift keying.

[0064] It should be noted that the standard modulation signal is a signal directly output after modulation, and is not transmitted through a channel, so it does not contain noise in the communication channel, while noise exists in historical communication signals.

[0065] further, Figure 4 A schematic diagram of standard modulation signals of each user node in each time period provided by an embodiment of the present application is shown as follows: Figure 4 As shown, the horizontal axis represents the sampling order, the vertical axis represents the signal amplitude, and the standard modulation signal is not interfered by noise compared to the historical communication signal, and the noise information in the historical communication signal can be extracted later.

[0066] Further, analyzing the difference between the historical communication signal and the standard modulation signal to extract the noise time domain signal specifically includes:

[0067] The difference between the historical communication signal of each user node in each time period and the standard modulation signal in the corresponding time period is used as the noise time domain signal.

[0068] It should be noted that the historical communication signal and the standard modulation signal are vectors of the same length. Therefore, the difference between the historical communication signal of each user node in each time period and the standard modulation signal of the corresponding time period is used as the noise time domain signal, wherein the noise time domain signal also represents a vector, and the length of the vector represented by the noise time domain signal is the same as the length of the historical communication signal and the standard modulation signal, indicating that the waveform distortion of the user information when it is transmitted in the channel includes the noise encountered by the user node when transmitting information.

[0069] Further, the noise time domain signal is subjected to frequency domain analysis to obtain the noise spectrum diagram of each user node in each time period, specifically including:

[0070] A frequency domain analysis algorithm is used to obtain a noise spectrum diagram of the noise time domain signal of each user node in each time period.

[0071] Preferably, in this embodiment, a fast Fourier transform algorithm is used to perform frequency domain analysis to obtain a noise spectrum diagram, wherein the fast Fourier transform algorithm is a well-known technology and will not be described in detail here. As other implementation methods, implementers can adopt other methods of the prior art, such as Hilbert transform, etc., and this embodiment does not impose any special restrictions on this.

[0072] It should be noted that the noise spectrum diagram contains the noise frequency information of the user node transmission channel. The horizontal axis of the spectrum diagram is frequency, and the vertical axis is energy amplitude. The frequency range is limited to 50k to 450k Hz. The frequency position corresponding to the large energy amplitude is represented as the noise-intensive frequency position. This frequency range should be avoided when selecting the carrier frequency.

[0073] Furthermore, a flowchart of the steps of a method for obtaining a noise spectrum diagram of each user node in each time period provided by an embodiment of the present application is as follows: Figure 5 shown.

[0074] At this point, the noise spectrum diagram of each user node in each time period is obtained.

[0075] Step S130, determining the noise difference between each user node and the remaining user nodes in each time period according to the difference in noise spectrum diagrams of different user nodes in the same time period; and determining the channel overlap between each user node and the remaining user nodes based on the noise difference.

[0076] When using the power grid for communication, noise is divided into white noise and colored noise. White noise is noise randomly distributed in the frequency domain, and it is impossible to avoid noise by adjusting the carrier frequency; colored noise has a relatively fixed position in the frequency domain, and it can be avoided by adjusting the carrier frequency. Therefore, colored noise is extracted.

[0077] Colored noise is usually caused by fixed devices such as power cable impedance and user electrical appliances. Therefore, this noise has a strong periodicity and is usually a daily cycle. For example, at certain times of the day, an electrical appliance works and causes current fluctuations in the power cable, causing noise and interfering with nearby communication channels. At certain times of the day, the electrical appliance is dormant and the noise disappears. Due to the periodicity of colored noise and the regional characteristics of the impact range of noise, the similarity of colored noise between different user nodes is analyzed to judge the difference in communication channels of two users and determine the channel overlap. Therefore, for two user nodes with high channel overlap, the noise frequency domain characteristics of the two can be considered when selecting the carrier frequency.

[0078] First, the similarity of colored noise between different user nodes is analyzed, that is, according to the difference of noise spectrum diagrams of different user nodes in the same period, the difference of noise between each user node and other user nodes in each period is determined, specifically including:

[0079] All energy amplitudes in the noise spectrum diagram are used to form the noise frequency domain vector of each user node in each time period; the difference degree of the noise frequency domain vector between each user node and the other user nodes in the same time period is recorded as the noise difference degree of each time period.

[0080] Preferably, in this embodiment, the Euclidean distance of the noise frequency domain vector between each user node and the other user nodes in the same time period is recorded as the noise difference, wherein the Euclidean distance is a well-known technology and will not be repeated here. As other implementation methods, the implementer can adopt other methods of the prior art, such as DTW distance, etc., and this embodiment does not impose any special restrictions on this.

[0081] It should be noted that the noise difference indicates the similarity of the noise spectra of two user nodes at corresponding moments in the same time period. The smaller the noise difference, the more similar the noises of the two user nodes in the same time period.

[0082] Since white noise is random noise with stable energy in the spectrum, the difference brought by white noise for any two noise frequency domain vectors is fixed. Therefore, the greater the noise difference, the greater the difference in the colored noise of the channels where the two user nodes are located, and the lower the channel overlap.

[0083] Furthermore, at different times of the day, the causes of colored noise are different, and the locations where colored noise is generated are also different; if the channels of two users overlap in residential areas but do not overlap when passing through industrial areas, or if more electrical appliances are used in residential areas at night and the noise is stronger, while more electrical appliances are used in industrial areas during the day and the noise is stronger, then the difference between the noise frequency domain vectors of the two user nodes will be small when communicating during the day, and large when communicating at night.

[0084] Therefore, if the difference in the noise frequency domain vectors of two user nodes is relatively stable within a day, it means that the channels of the two user nodes do not overlap highly in a certain section, but the channel overlap is high during the entire transmission process. Therefore, it is necessary to analyze the channel overlap of the two nodes by observing the difference in the noise frequency domain vectors at all times within a day, and determine the channel overlap between each user node and the remaining user nodes based on the noise difference, specifically including:

[0085] The discrete degree and the mean value of the noise difference between each user node and the other user nodes in all time periods are calculated respectively; and the inverse of the product of the discrete degree and the mean value is used as the channel overlap between each user node and the other user nodes.

[0086] Preferably, in some embodiments of the present application, the standard deviation of the noise difference between each user node and the remaining user nodes in all time periods is calculated. As other implementation methods, the implementer can use other methods of the prior art to measure the degree of discreteness, such as variance, coefficient of variation, information entropy, etc. This embodiment does not impose any special restrictions on this.

[0087] It should be noted that the smaller the degree of discreteness, the more the channels of the two user nodes overlap in the entire communication channel. The higher the obtained channel overlap, the smaller the mean, which means that the different channel positions of the two user nodes overlap more at various power usage times in a day. The higher the obtained channel overlap, the more the communication channels of the two user nodes overlap, and the more they should learn from each other when selecting carrier frequencies.

[0088] It should be noted that the channel overlap between a user node and itself is 1, which means that the node's own channel completely overlaps.

[0089] Furthermore, a flowchart of a method for obtaining the channel overlap between each user node and other user nodes provided in an embodiment of the present application is as follows: Figure 6 shown.

[0090] At this point, the channel overlap between each of the user nodes and the remaining user nodes is obtained.

[0091] Step S140, based on the noise spectrum diagram of all time periods between each of the user nodes and the remaining user nodes, combined with the channel overlap, extract the colored noise signal of each of the user nodes; and based on the colored noise signal, determine the optimal carrier frequency of each of the user nodes, and perform carrier communication on the communication signal of the user node.

[0092] For each of the user nodes, its noise frequency domain vector contains colored noise and white noise, wherein colored noise is the noise that needs to be paid attention to when selecting the carrier frequency, and white noise is the random noise with stable energy in the entire system. Therefore, it is necessary to remove the white noise part in the noise frequency vector. For nodes with a high channel overlap with each of the user nodes, the greater the degree of mutual influence between the noise characteristics of the two user nodes, the more similar the colored noise of the two are. At the same time, the white noise is the same in all noise frequency domain vectors. Therefore, the noise frequency domain vectors are weighted and summed with the channel overlap as the weight to eliminate the white noise component of the noise frequency domain vector and achieve the purpose of highlighting the colored noise component, which specifically includes:

[0093] The calculation formula of the colored noise signal of the nth user node is: Among them, U n is the colored noise signal of the nth user node, α n,m is the channel overlap between the nth user node and the mth user node, V n,h is the noise frequency domain vector of the hth time period of the nth user node, N is the number of all user nodes, and H is the number of all time periods.

[0094] It should be noted that V n,h Represented as a vector, α n,m ×V n,h is also a vector. The noise frequency domain vectors of the nth user node and all its user nodes in the same period are weighted and summed to obtain Also expressed as a vector, the vector is averaged, so the obtained U n Also expressed as a vector; secondly, when m = n, α n,n Indicates the channel overlap between the nth user node and itself, at this time α n,n The value is 1; assuming two vectors [a1, a2, α3] and [b1, b2, b3], the sum of the two vectors is: [a1+b1, a2+b2, a3+b3], and the mean vector of the two vectors is:

[0095]

[0096] It should be noted that each element in the noise frequency domain vector corresponds to a frequency in the noise spectrum, so U n Each element in it also corresponds to a frequency, α n,m ×V n,j The larger the value of the element in the corresponding vector, the more obvious the colored noise at the frequency corresponding to the element; n The frequency position with a larger internal element value has a more serious colored noise component, and finally this frequency position should be avoided when selecting the carrier frequency.

[0097] Further, based on the colored noise signal, determining the optimal carrier frequency of each of the user nodes specifically includes:

[0098] The frequency corresponding to the minimum element value in the colored noise signal of each user node in the noise spectrum diagram is used as the optimal carrier frequency of each user node on that day.

[0099] It should be noted that the frequency corresponding to the minimum element value is the frequency with the least noise interference in the channel of each user node. Selecting a frequency with small colored noise as the carrier frequency can effectively reduce the noise interference of power line carrier communication and avoid communication errors.

[0100] Further, based on the optimal carrier frequency, the modulation signal is used to perform carrier communication on the communication signal of the user node, specifically including:

[0101] The digital bit stream that each user needs to transmit on that day is obtained, and a signal modulation algorithm is adopted, wherein the carrier frequency of the day is set to the optimal carrier frequency of the day, the signal modulation mode is ASK amplitude shift keying, and a modulated signal is output.

[0102] At the same time, after the modulated signal is sent to the power line for transmission, a signal demodulation algorithm is used, in which the carrier frequency is set to the optimal carrier frequency, the signal modulation method is ASK amplitude shift keying, and the output is a digital bit stream. The digital bit stream is the information that the user needs to transmit, thereby completing the power line carrier communication.

[0103] Depend on Figure 1It can be seen from the method shown that the present application is based on the historical communication signal of the user node, and obtains the standard modulation signal of each user node in each time period through the demodulation and modulation process. The standard modulation signal is a communication signal that does not contain noise in the communication channel, so as to extract the noise signal later; the difference between the historical communication signal and the standard modulation signal is analyzed, the noise time domain signal is extracted, and the noise spectrum diagram of each user node in each time period is obtained. This step takes into account the interference of the channel noise during the signal transmission process, and extracts the noise signal to perform frequency domain analysis on it; according to the difference in the noise spectrum diagram of the same time period between different user nodes, the noise difference degree between each user node and the remaining user nodes in each time period is determined; Based on the noise difference, the channel overlap between each user node and the remaining user nodes is determined. Since the differences in the influence of noise in the channel when transmitting signals between different user nodes are taken into account, it reflects the overlap of the channels when different user nodes transmit signals, and further indicates that the two user nodes can use the same carrier frequency for signal modulation; based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes, combined with the channel overlap, the colored noise signal of each user node is extracted, and the random white noise in the noise time domain signal is eliminated to extract the colored noise signal; based on the colored noise signal, the optimal carrier frequency of each user node on the day is determined, and the communication signal of the user node is carried out as a carrier communication. The present application can effectively reduce the noise interference on power line carrier communication and avoid errors in communication transmission.

[0104] Figure 7 A schematic diagram of the structure of a power line carrier modulation device for a carrier chip according to an embodiment of the present application is shown. Figure 7 It can be seen that the power line carrier modulation device 700 for the carrier chip includes:

[0105] An acquisition unit 710 is used to acquire historical communication signals of multiple user nodes in each time period after being transmitted via the power line the day before the current day;

[0106] The first modulation unit 720 is used to obtain the standard modulation signal of each user node in each time period through demodulation and modulation process based on the historical communication signal; and analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time domain signal, and obtain the noise spectrum diagram of each user node in each time period;

[0107] The second modulation unit 730 is used to determine the noise difference between each user node and the other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes; and determine the channel overlap between each user node and the other user nodes based on the noise difference;

[0108] The third modulation unit 740 is used to extract the colored noise signal of each user node based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes and the channel overlap; and based on the colored noise signal, determine the optimal carrier frequency of each user node on that day, and perform carrier communication on the communication signal of each user node.

[0109] In some embodiments of the present application, in the above-mentioned device, the first modulation unit 720 is used to adopt a signal demodulation algorithm to obtain a digital bit stream corresponding to the historical communication signal of each user node in each time period based on the carrier frequency when each user node performed power line communication on the historical communication signal on the day before the current day; and adopt a signal modulation algorithm to modulate the digital bit stream of each user node in each time period to obtain a standard modulation signal of each user node in each time period.

[0110] In some embodiments of the present application, in the above-mentioned device, the first modulation unit 720 is used to use the difference between the historical communication signal of each user node in each time period and the standard modulation signal of the corresponding time period as the noise time domain signal of each user node in each time period.

[0111] In some embodiments of the present application, in the above-mentioned device, the first modulation unit 720 is used to draw a noise spectrum diagram of the noise time domain signal of each user node in each time period by using a frequency domain analysis algorithm.

[0112] In some embodiments of the present application, in the above-mentioned device, the second modulation unit 730 is used to form a noise frequency domain vector of each user node in each time period with all energy amplitudes in the noise spectrum diagram; and use the degree of difference between the noise frequency domain vectors of the same time period between each user node and the remaining user nodes as the noise difference degree between each user node and the remaining user nodes in each time period.

[0113] In some embodiments of the present application, in the above-mentioned device, the second modulation unit 730 is used to respectively calculate the discrete degree and the mean value of the noise difference between each of the user nodes and the remaining user nodes in all time periods; and take the inverse of the product of the discrete degree and the mean value as the channel overlap between each of the user nodes and the remaining user nodes.

[0114] In some embodiments of the present application, in the above device, the colored noise signal is calculated as follows:

[0115]

[0116] Among them, U n is the colored noise signal of the nth user node, α n,mis the channel overlap between the nth user node and the mth user node, V n,h is the noise frequency domain vector of the hth time period of the nth user node, N is the number of all user nodes, and H is the number of all time periods.

[0117] In some embodiments of the present application, in the above-mentioned device, the third modulation unit 740 is used to use the frequency corresponding to the minimum element value in the colored noise signal of each user node in the noise spectrum diagram as the optimal carrier frequency of each user node on that day; based on the optimal carrier frequency, a signal modulation algorithm is used to modulate the digital bit stream of each user node on that day, and a modulated signal is output. After the modulated signal is sent to the power line for transmission, a signal demodulation algorithm is used to output it as a digital bit stream.

[0118] It should be noted that the power line carrier modulation device for the carrier chip of the present application can implement the aforementioned power line carrier modulation method for the carrier chip in a one-to-one correspondence, which will not be described in detail here.

[0119] Based on the same inventive concept as the above method, an embodiment of the present application also provides a power line carrier modulation system for a carrier chip, and the power line carrier modulation system for a carrier chip includes: a processor and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, the steps of any one of the above-mentioned power line carrier modulation methods for a carrier chip are implemented.

[0120] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0121] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the present application. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solution of the present application, shall fall within the protection scope of the technical solution of the present application.

Claims

1. A power line carrier modulation method for a carrier chip, characterized in that: include: Obtain historical communication signals of multiple user nodes in each time period after being transmitted via the power line the day before the current day; Based on the historical communication signal, a standard modulation signal of each user node in each time period is obtained through a demodulation and modulation process; and the difference between the historical communication signal and the standard modulation signal is analyzed, the noise time domain signal is extracted, and a noise spectrum diagram of each user node in each time period is obtained; Determine the noise difference between each user node and the other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes; and determine the channel overlap between each user node and the other user nodes based on the noise difference; Based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes and the channel overlap, the colored noise signal of each user node is extracted; and based on the colored noise signal, the optimal carrier frequency of each user node on that day is determined, and carrier communication is performed on the communication signal of each user node.

2. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The method of obtaining the standard modulation signal of each user node in each time period through a demodulation and modulation process based on the historical communication signal includes: Based on the carrier frequency of each user node when performing power line communication on the historical communication signal on the day before the current day, a signal demodulation algorithm is used to obtain a digital bit stream corresponding to the historical communication signal of each user node in each time period; A signal modulation algorithm is used to modulate the digital bit stream of each user node in each time period to obtain a standard modulation signal of each user node in each time period.

3. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The step of analyzing the difference between the historical communication signal and the standard modulation signal to extract the noise time domain signal includes: The difference between the historical communication signal of each user node in each time period and the standard modulation signal of the corresponding time period is used as the noise time domain signal of each user node in each time period.

4. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The obtaining of the noise spectrum diagram of each user node in each time period includes: A frequency domain analysis algorithm is used to draw a noise spectrum diagram of the noise time domain signal of each user node in each time period.

5. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: Determining the noise difference between each user node and other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes includes: All energy amplitudes in the noise spectrum graph are used to form a noise frequency domain vector for each user node in each time period; The difference degree of the noise frequency domain vector between each user node and the other user nodes in the same time period is used as the noise difference degree between each user node and the other user nodes in each time period.

6. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The determining, based on the noise difference, the channel overlap between each of the user nodes and the remaining user nodes comprises: Calculate the discrete degree and mean value of the noise difference between each user node and the other user nodes in all time periods respectively; The inverse of the product of the discrete degree and the mean value is used as the channel overlap degree between each of the user nodes and the remaining user nodes.

7. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The colored noise signal is calculated as follows: Among them, U m is the colored noise signal of the nth user node, α n,m is the channel overlap between the nth user node and the mth user node, V n,h is the noise frequency domain vector of the hth time period of the nth user node, N is the number of all user nodes, and H is the number of all time periods.

8. The power line carrier modulation method for a carrier chip according to claim 1, characterized in that: The determining the optimal carrier frequency of each user node based on the colored noise signal and performing carrier communication transmission on the communication information of the user node comprises: The frequency corresponding to the minimum element value in the colored noise signal of each user node in the noise spectrum diagram is used as the optimal carrier frequency of each user node on that day; Based on the optimal carrier frequency, a signal modulation algorithm is used to modulate the digital bit stream of each user node on that day, and a modulated signal is output. After the modulated signal is sent to the power line for transmission, a signal demodulation algorithm is used to output it as a digital bit stream.

9. A power line carrier modulation device for a carrier chip, characterized in that: The device comprises: An acquisition unit, used for acquiring historical communication signals of multiple user nodes in each time period after being transmitted via the power line the day before the current day; A first modulation unit is used to obtain a standard modulation signal of each user node in each time period through a demodulation and modulation process based on the historical communication signal; and analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time domain signal, and obtain a noise spectrum diagram of each user node in each time period; A second modulation unit is used to determine the noise difference between each user node and the other user nodes in each time period according to the difference of the noise spectrum diagrams in the same time period between different user nodes; and determine the channel overlap between each user node and the other user nodes based on the noise difference; The third modulation unit is used to extract the colored noise signal of each user node based on the noise spectrum diagram of all time periods between each user node and the remaining user nodes and the channel overlap; and based on the colored noise signal, determine the optimal carrier frequency of each user node on that day, and perform carrier communication on the communication signal of each user node.

10. A power line carrier modulation system for a carrier chip, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the power line carrier modulation method for a carrier chip as described in any one of claims 1 to 8 are implemented.

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