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

Abstract

This application relates to the technical field of communication signal transmission, and specifically relates to a power line carrier modulation method, device and system for a carrier chip. The method includes: obtaining the historical communication signals of each user node at each time period after being transmitted through the power line on the day before the current day; obtaining the standard modulation signals of each user node at each time period; extracting the noise time-domain signal to obtain the noise spectrogram of each user node at each time period; determining the noise difference degree between each user node and each of the remaining user nodes at each time period; determining the channel coincidence degree between each user node and each of the remaining user nodes; extracting the colored noise signal of each user node; determining the optimal carrier frequency of each user node on the current day, and performing carrier communication on the communication signals of the user nodes. This application can effectively reduce the noise interference suffered by power line carrier communication and avoid communication transmission errors.

Description

Technical Field

[0001] The present application relates to the technical field of communication signal transmission, and particularly relates 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 a baseband signal and a carrier signal to generate a modulated signal. Power line carrier communication (PLC) is a communication method that uses alternating current as the carrier signal and power cables as the channel. When the carrier chip is used in the field of power line carrier modulation, it can be used for the transmission of electricity consumption information on the user side, facilitating the power grid to collect the electricity consumption information of users in real time.

[0003] When transmitting a modulated signal through a power line, there is a large amount of noise in the power cable. The noise not only includes white noise, but also colored noise emitted by various electrical appliances, which will interfere with the communication of PLC; colored noise usually has a fixed frequency range and causes greater interference to the communication signal, affecting the communication effect. Therefore, when obtaining the modulated signal, it is necessary to select an appropriate carrier frequency to avoid the frequency range with greater interference to ensure that the communication does not make mistakes. Therefore, in power line carrier modulation, there is a problem that the modulated signal is seriously interfered due to improper selection of the carrier frequency, resulting in 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, including the following steps:

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

[0007] Based on the historical communication signals, through the processes of demodulation and modulation, obtain the standard modulation signals of each user node at each time period; and analyze the difference between the historical communication signals and the standard modulation signals, extract the noise time-domain signals, and obtain the noise spectrograms of each user node at each time period;

[0008] According to the difference between the noise spectrograms of different user nodes at the same time period, determine the noise difference degree between each user node and the other user nodes at each time period; and based on the noise difference degree, determine the channel coincidence degree between each user node and the other user nodes;

[0009] Extract the colored noise signals of each user node based on the coincidence degree between the noise spectrograms of all time periods between each user node and the other user nodes and the channel; and determine the optimal carrier frequency of each user node on the same day based on the colored noise signals, and perform carrier communication on the communication signals of each user node.

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

[0011] Based on the carrier frequencies when each user node performs power line communication on the historical communication signals in the day before the current day, use a signal demodulation algorithm to obtain the digital bitstreams corresponding to the historical communication signals of each user node at each time period;

[0012] Use a signal modulation algorithm to modulate the digital bitstreams of each user node at each time period to obtain the standard modulation signals of each user node at each time period.

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

[0014] Take the difference between the historical communication signals of each user node at each time period and the standard modulation signals of the corresponding time periods as the noise time-domain signals of each user node at each time period.

[0015] Optionally, in the above power line carrier modulation method for a carrier chip, the obtaining of the noise spectrograms of each user node at each time period includes:

[0016] Use a frequency-domain analysis algorithm to draw the noise spectrograms of the noise time-domain signals of each user node at each time period.

[0017] Optionally, in the above power line carrier modulation method for a carrier chip, the determining of the noise difference degrees between each user node and the other user nodes at each time period according to the difference situations of the noise spectrograms of the same time periods between different user nodes includes:

[0018] Form the noise frequency-domain vectors of each user node at each time period by all the energy amplitudes in the noise spectrograms;

[0019] Take the difference degree between the noise frequency-domain vectors of the same time periods between each user node and the other user nodes as the noise difference degrees between each user node and the other user nodes at each time period.

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

[0021] Calculating the dispersion degree and the mean value of the noise difference degrees between each of the user nodes and the remaining user nodes for all time periods respectively;

[0022] Taking the reciprocal of the product of the dispersion degree and the mean value as the channel overlap degree between each of the user nodes and the remaining user nodes.

[0023] Optionally, in the above power line carrier modulation method for a carrier chip, the calculation method of the colored noise signal is:

[0024]

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

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

[0027] Taking the frequency corresponding to the minimum element value in the colored noise signal of each of the user nodes in the noise spectrogram as the optimal carrier frequency of each of the user nodes on the current day;

[0028] Based on the optimal carrier frequency, modulating the digital bit stream of each of the user nodes on the current day by using a signal modulation algorithm, outputting a modulation signal, sending the modulation signal to the power line for transmission, and then using a signal demodulation algorithm to output a digital bit stream.

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

[0030] An acquisition unit, configured to acquire historical communication signals of multiple user nodes in each time period after being transmitted through the power line on the day before the current day;

[0031] The first modulation unit is configured to obtain the standard modulation signals of each user node at each time period through a demodulation and modulation process based on the historical communication signals; and analyze the difference between the historical communication signals and the standard modulation signals, extract the noise time-domain signals, and obtain the noise spectrograms of each user node at each time period.

[0032] The second modulation unit is configured to determine the noise difference degrees of each user node from the other user nodes at each time period according to the difference between the noise spectrograms of different user nodes at the same time period; and determine the channel coincidence degrees of each user node from the other user nodes based on the noise difference degrees.

[0033] The third modulation unit is configured to extract the colored noise signals of each user node based on the noise spectrograms and the channel coincidence degrees of all time periods between each user node and the other user nodes; and determine the optimal carrier frequencies of each user node on the current day based on the colored noise signals, and perform carrier communication on the communication signals of each user node.

[0034] In a third aspect, the present application further provides a power line carrier modulation system for a carrier chip, including a memory, a processor, and a computer program stored in the memory and running on the processor. The processor is characterized in that when executing the computer program, it implements the steps of the power line carrier modulation method for a carrier chip as described in any one of the foregoing.

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

[0036] Based on the historical communication signals of user nodes, through the processes of demodulation and modulation, the standard modulation signals of each user node at each time period are obtained. The standard modulation signals are communication signals that do not contain the noise in the communication channel, so as to extract the noise signals subsequently. Analyze the difference between the historical communication signals and the standard modulation signals, extract the noise time-domain signals, and obtain the noise spectrograms of each user node at each time period. This step takes into account the interference of the noise in the channel during the signal transmission process and extracts the noise signals for frequency-domain analysis. According to the difference between the noise spectrograms of different user nodes at the same time period, determine the noise difference degrees between each user node and the other user nodes at each time period. Based on the noise difference degrees, determine the channel coincidence degrees between each user node and the other user nodes. Since it takes into account the differences in the influence of the noise in the channel when different user nodes transmit signals, it reflects the coincidence situation of the channels when different user nodes transmit signals, and further indicates that the two user nodes are more likely to use the same carrier frequency for signal modulation. Based on the noise spectrograms of all time periods between each user node and the other user nodes, combined with the channel coincidence degrees, extract the colored noise signals of each user node, eliminating the random white noise in the noise time-domain signals to extract the colored noise signals. Based on the colored noise signals, determine the optimal carrier frequencies of each user node on the same day and perform carrier communication on the communication signals of the user nodes. This application can effectively reduce the noise interference suffered by power line carrier communication and avoid communication transmission errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following further elaborates on the power line carrier modulation method for a carrier chip according to the present application with reference to the accompanying drawings.

[0038] Figure 1 It is a schematic flowchart of the power line carrier modulation method for a carrier chip provided by an embodiment of the present application;

[0039] Figure 2 It is a schematic diagram of the historical communication signals of each user node at each time period provided by an embodiment of the present application;

[0040] Figure 3 It is a visual schematic diagram of the digital bit stream corresponding to the historical communication signals provided by an embodiment of the present application;

[0041] Figure 4 It is a schematic diagram of the standard modulation signals of each user node at each time period provided by an embodiment of the present application;

[0042] Figure 5 It is a schematic flowchart of the method for obtaining the noise spectrograms of each user node at each time period provided by an embodiment of the present application;

[0043] Figure 6Schematic flowchart of the method for obtaining the channel overlap degree between each user node provided in the embodiments of the present application and the remaining user nodes;

[0044] Figure 7 Shows a schematic structural diagram of a power line carrier modulation device for a carrier chip according to an embodiment of the present application. Detailed implementation manners

[0045] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further details the power line carrier modulation method and system for a carrier chip proposed in the present application in conjunction with the accompanying drawings and implementation examples. It should be understood that the specific implementation examples described herein are only used to explain the present application and are not used to limit the present application.

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

[0047] Please refer to Figure 1 , which shows a schematic flowchart of a power line carrier modulation method for a carrier chip provided by an embodiment of the present application. This embodiment includes steps S110 to S140:

[0048] Step S110: Obtain the historical communication signals of each of the user nodes at each time period on the day before the current day after being transmitted through the power line.

[0049] A power line carrier communication (PLC) system encodes, modulates, and couples signals for the original communication data, converts it into a signal that can be transmitted on the power line. After being transmitted 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 line is affected by different grid loads and interference conditions at different times of the day, which may affect the transmission quality of PLC signals, therefore, obtain the communication data of the day before the current day of each of the user nodes from the grid control center. The communication data refers to the modulated signals received by the grid control center from the users, and the communication signals with noise after the modulated signals are transmitted through the power line. The acquisition time interval is t, and the historical communication data of each time period is obtained. 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 signals of each of the user nodes at each time period.

[0051] Preferably, in some embodiments of the present application, the time interval t is 10 min. Every 10 min, the historical communication data of each time period is obtained. It should be noted that if every 10 min is taken as a time period, then a total of 144 time periods of communication data are collected within the day before the current day. Secondly, since the frequency of power line carrier communication is usually between 50 k and 450 k Hertz, 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 900 k Hertz, and the vector length is 540 megabytes.

[0052] Further, please refer to Figure 2 , Figure 2 which shows the schematic diagram of the historical communication signals of each of the user nodes at each time period provided by an embodiment of the present application. As shown in Figure 2 , where the abscissa represents the sampling order and the ordinate represents the signal amplitude. It can be clearly observed from Figure 2 that the historical communication signals are interfered by various noises.

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

[0054] Step S120: Based on the historical communication signals, through the demodulation and modulation processes, obtain the standard modulation signals of each of the user nodes at each time period; and analyze the difference between the historical communication signals and the standard modulation signals, extract the noise time-domain signals, and obtain the noise spectrograms of each of the user nodes at each time period.

[0055] For the historical communication signals, for the transmitted digital information, which contains the information of the noise suffered by the communication data, it is necessary to extract the noise information therefrom. When determining the carrier frequency, avoid the frequency domain where the noise is concentrated to achieve the purpose of avoiding information transmission errors.

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

[0057] Based on the carrier frequency when each of the user nodes performs power line communication on the historical communication signals in the day before the current day, use a signal demodulation algorithm to obtain the digital bit stream corresponding to the historical communication signals of each of the user nodes at each time period.

[0058] In some embodiments of the present application, the signal demodulation algorithm can be any one in the prior art and will not be elaborated here. Secondly, the carrier frequency in the signal demodulation algorithm is the carrier frequency of the day before the current day, and the signal modulation method is ASK amplitude shift keying; among them, the obtained digital bit stream is the information that the user needs to transmit.

[0059] It should be noted that when the user conducts PLC communication on the first day, a fixed frequency is used as the carrier frequency. Starting from the second day, the optimal carrier frequency for the current day is calculated based on the historical communication signals of the previous day and used as the carrier frequency for the current day. In some embodiments of the present application, the fixed frequency is 250 kHz.

[0060] Furthermore, Figure 3 Fig. shows a visualization diagram of the digital bit stream corresponding to the historical communication signal provided by an embodiment of the present application, as Figure 3 shown, where the abscissa represents the sampling order and the ordinate represents the signal amplitude.

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

[0062] Using a signal modulation algorithm, the digital bit streams of each user node at each time period are modulated to obtain the standard modulation signals of each user node at each time period;

[0063] In some embodiments of the present application, the signal modulation algorithm can be any one in the prior art and will not be elaborated here; the carrier frequency in the signal modulation algorithm is the carrier frequency of the day before the current day, and the signal modulation method is ASK amplitude shift keying.

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

[0065] Furthermore, Figure 4 Fig. shows a schematic diagram of the standard modulation signals of each user node at each time period provided by an embodiment of the present application, as Figure 4 shown, where the abscissa represents the sampling order and the ordinate represents the signal amplitude. The standard modulation signal is not interfered by noise compared with the historical communication signal, and the noise information in the historical communication signal can be extracted subsequently.

[0066] Furthermore, analyze the difference between the historical communication signal and the standard modulation signal, and extract the noise time-domain signal, specifically including:

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

[0068] It should be noted that the historical communication signals and the standard modulation signals are vectors of the same length. Therefore, the difference between the historical communication signals of each user node in each time period and the standard modulation signals in the corresponding time period is used as the noise time-domain signal. Here, 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 that of the historical communication signal and the standard modulation signal, indicating the waveform distortion suffered by the user information during transmission in the channel and including the noise encountered by the user node during information transmission.

[0069] Furthermore, perform frequency-domain analysis on the noise time-domain signal to obtain the noise spectrograms of each user node in each time period, specifically including:

[0070] Adopt a frequency-domain analysis algorithm to obtain the noise spectrograms of the noise time-domain signals of each user node in each time period.

[0071] Preferably, in this embodiment, the fast Fourier transform algorithm is used for frequency-domain analysis to obtain the noise spectrogram. Among them, the fast Fourier transform algorithm is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the existing technology, such as the Hilbert transform, etc. This embodiment does not make special restrictions on this.

[0072] It should be noted that in the noise spectrogram, the noise frequency information of the transmission channel of the user node is included. The abscissa of the spectrogram is the frequency, and the ordinate is the energy amplitude. The frequency range is limited to 50k to 450k Hertz. Among them, the frequency position corresponding to a large energy amplitude represents the frequency position where the noise is dense, and this frequency range should be avoided when selecting the carrier frequency.

[0073] Furthermore, the step flow chart of the method for obtaining the noise spectrograms of each user node in each time period provided by an embodiment of the present application is as Figure 5 shown.

[0074] Thus, the noise spectrograms of each user node in each time period are obtained.

[0075] Step S130, determine the noise difference degree between each user node and each of the remaining user nodes in each time period according to the difference situation of the noise spectrograms of the same time period between different user nodes; and determine the channel coincidence degree between each user node and each of the remaining user nodes based on the noise difference degree.

[0076] When using the power grid for communication, the noise is divided into white noise and colored noise. Among them, white noise is randomly distributed in the frequency domain and cannot achieve the purpose of avoiding noise by adjusting the carrier frequency; colored noise has a relatively fixed position in the frequency domain and can achieve the purpose of avoiding noise by adjusting the carrier frequency. Therefore, extract the colored noise.

[0077] Colored noise is usually caused by fixed devices such as the impedance of power cables and the user's electrical appliances. Therefore, this kind of noise has strong periodicity and usually has a daily cycle. For example, at certain times of the day, an electrical appliance works and causes current fluctuations in the power cable, resulting in noise, which interferes with the nearby communication channels. At certain times of the day, the electrical appliance goes into standby and the noise disappears. Due to the periodicity of colored noise and the regional characteristics of the noise influence range, by analyzing the similarity degree of colored noise between different user nodes, the difference situation of the communication channels of two users can be judged, and the channel overlap degree can be determined. Thus, for two user nodes with a high channel overlap degree, when selecting the carrier frequency, the noise frequency domain characteristics of both can be considered mutually.

[0078] First, analyze the similarity degree of colored noise between different user nodes, that is, determine the noise difference degree of each time period between each of the user nodes and the remaining user nodes according to the difference situation of the noise spectrograms of the same time period between different user nodes. Specifically, it includes:

[0079] Form the noise frequency domain vectors of each time period of each user node by all the energy amplitudes in the noise spectrogram; record the difference degree of the noise frequency domain vectors of the same time period between each user node and the remaining user nodes as the noise difference degree of each time period.

[0080] Preferably, in this embodiment, the Euclidean distance of the noise frequency domain vectors of the same time period between each user node and the remaining user nodes is recorded as the noise difference degree. Among them, the Euclidean distance is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the existing technology, such as the DTW distance, etc. This embodiment does not make special restrictions on this.

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

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

[0083] Furthermore, at different times of the day, the causes of colored noise are different, and the locations where colored noise is generated also have differences. If the channels of two users are more overlapping in the residential area and not overlapping when passing through the industrial area, or there are more electrical appliances in the residential area at night and the noise is stronger, and there are more electrical appliances in the industrial area during the day and the noise is stronger, there will be a situation where the difference between the noise frequency domain vectors during the day communication of the two user nodes is small, and the difference between the noise frequency domain vectors during the night communication is large.

[0084] Therefore, if the difference between the noise frequency domain vectors of two user nodes is relatively stable within a day, it indicates that the channels of the two user nodes do not have a high degree of overlap in a certain section, but rather have a high degree of overlap in the entire transmission process. Therefore, it is necessary to observe the difference in the noise frequency domain vectors at all times within a day, analyze the channel overlap of the two nodes, and determine the channel overlap degree between each of the user nodes and the other user nodes based on the noise difference degree. Specifically, it includes:

[0085] Calculate the dispersion degree and mean value of the noise difference degree at all time periods between each of the user nodes and the other user nodes respectively; take the reciprocal of the product of the dispersion degree and the mean value as the channel overlap degree between each of the user nodes and the other user nodes.

[0086] Preferably, in some embodiments of the present application, calculate the standard deviation of the noise difference degree at all time periods between each of the user nodes and the other user nodes. As other implementation manners, implementers can use other methods in the prior art to measure the dispersion degree, such as variance, coefficient of variation, information entropy, etc. This embodiment does not make special restrictions on this.

[0087] It should be noted that the smaller the dispersion degree, the more the channels of the two user nodes overlap in the entire communication channel, and the higher the obtained channel overlap degree. The smaller the mean value, the more the two user nodes overlap at different channel positions at each power consumption moment within a day, and the higher the obtained channel overlap degree, indicating that the communication channels of the two user nodes overlap more, and they should learn from each other more when selecting carrier frequencies.

[0088] It should be noted that the channel overlap degree of a user node with itself is 1, representing that the channel of the node itself completely overlaps.

[0089] Furthermore, the step flow chart of the method for obtaining the channel overlap degree between each of the user nodes and the other user nodes provided by an embodiment of the present application is as Figure 6 shown.

[0090] Thus, the channel overlap degree between each of the user nodes and the other user nodes is obtained.

[0091] Step S140, based on the noise spectrograms at all time periods between each of the user nodes and the other user nodes, and in combination with the channel overlap degree, extract the colored noise signals of each of the user nodes; and based on the colored noise signals, determine the optimal carrier frequency of each of the user nodes, and perform carrier communication on the communication signals of the user nodes.

[0092] For each of the user nodes, the noise frequency domain vector contains colored noise and white noise. Among them, the colored noise is the noise that needs to be concerned about when selecting the carrier frequency, and the 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 the nodes with a high channel overlap degree with each of the user nodes, the greater the mutual influence degree of the noise characteristics of the two user nodes, the more similar their colored noises are. At the same time, the white noise is the same in all noise frequency domain vectors. Therefore, using the channel overlap degree as the weight, the noise frequency domain vectors are weighted and summed to eliminate the white noise component in the noise frequency domain vector and achieve the purpose of highlighting the colored noise component, which specifically includes:

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

[0094] It should be noted that V n,h is expressed as a vector, and α n,m ×V n,h is also a vector. The noise frequency domain vectors of the nth user node and all other user nodes in the same period are weighted and summed to obtain which is also expressed as a vector. The mean vector of the vector is calculated, so the obtained U n is also expressed as a vector; secondly, when m = n, α n,n represents the channel overlap degree of the nth user node with itself, and at this time α n,n takes the value of 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 spectrogram. Therefore, each element in U n also corresponds to a frequency. The larger the value of the element corresponding to α n,m ×V n,j in the vector, the more obvious the colored noise at the frequency corresponding to the element; the larger the value of the element in U n , the more serious the colored noise component at the corresponding frequency position, and the more the frequency position should be avoided when selecting the carrier frequency finally.

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

[0098] Use the frequency corresponding to the minimum element value in the colored noise signal of each user node in the noise spectrogram as the optimal carrier frequency for each user node on the current 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 channels of each user node. Selecting a frequency with less colored noise as the carrier frequency can effectively reduce the noise interference suffered by power line carrier communication and avoid communication errors.

[0100] Further, based on the optimal carrier frequency, modulate the signal and perform carrier communication on the communication signals of the user nodes, specifically including:

[0101] Obtain the digital bitstreams that each user needs to transmit on the current day, and use a signal modulation algorithm. Among them, set the carrier frequency on the current day as the optimal carrier frequency on the current day, and the signal modulation method as ASK amplitude shift keying, and output the modulated signal.

[0102] At the same time, after sending the modulated signal to the power line for transmission, use a signal demodulation algorithm. Among them, set the carrier frequency as the optimal carrier frequency, the signal modulation method as ASK amplitude shift keying, and the output as a digital bitstream. The digital bitstream is the information that the user needs to transmit, thereby completing power line carrier communication.

[0103] By Figure 1As can be seen from the method shown, based on the historical communication signals of user nodes, through the demodulation and modulation processes, the standard modulation signals of each user node at each time period are obtained. The standard modulation signal is a communication signal that does not contain the noise in the communication channel, so as to extract the noise signal subsequently; analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time-domain signal, and obtain the noise spectrogram of each user node at each time period. This step takes into account the interference of the noise in the channel during the signal transmission process and extracts the noise signal for frequency-domain analysis; according to the difference in the noise spectrograms of different user nodes at the same time period, determine the noise difference degree between each user node and the other user nodes at each time period; based on the noise difference degree, determine the channel coincidence degree between each user node and the other user nodes. Since the difference in the influence of the noise in the channel on the transmitted signals between different user nodes is considered, it reflects the coincidence of the channels when different user nodes transmit signals, and further indicates that the two user nodes are more likely to use the same carrier frequency for signal modulation; based on the noise spectrograms of all time periods between each user node and the other user nodes, combined with the channel coincidence degree, extract the colored noise signal of each user node, eliminating the random white noise in the noise time-domain signal to extract the colored noise signal; based on the colored noise signal, determine the optimal carrier frequency of each user node on the same day, and perform carrier communication on the communication signals of the user nodes. This application can effectively reduce the noise interference suffered by power line carrier communication and avoid communication transmission errors.

[0104] Figure 7 FIG. shows a schematic structural diagram of a power line carrier modulation device for a carrier chip according to an embodiment of the present application. From Figure 7 it can be seen that the power line carrier modulation device 700 for a carrier chip includes:

[0105] An acquisition unit 710, configured to acquire the historical communication signals of multiple user nodes at each time period after being transmitted through the power line on the day before the current day;

[0106] A first modulation unit 720, configured to obtain the standard modulation signals of each of the user nodes at each time period based on the historical communication signals through the demodulation and modulation processes; and analyze the difference between the historical communication signal and the standard modulation signal, extract the noise time-domain signal, and obtain the noise spectrogram of each of the user nodes at each time period;

[0107] A second modulation unit 730, configured to determine the noise difference degree between each of the user nodes and the other user nodes at each time period according to the difference in the noise spectrograms of different user nodes at the same time period; and determine the channel coincidence degree between each of the user nodes and the other user nodes based on the noise difference degree;

[0108] A third modulation unit 740, configured to extract the colored noise signals of each user node based on the coincidence degree between the noise spectrograms of all time periods between each user node and the remaining user nodes and the channel; and determine the optimal carrier frequency of each user node on the current day based on the colored noise signals, and perform carrier communication on the communication signals of each user node.

[0109] In some embodiments of the present application, in the above device, a first modulation unit 720 is configured to obtain the digital bitstreams corresponding to the historical communication signals of each user node in each time period by using a signal demodulation algorithm based on the carrier frequencies when each user node performs power line communication on the historical communication signals on the day before the current day; and modulate the digital bitstreams of each user node in each time period by using a signal modulation algorithm to obtain the standard modulation signals of each user node in each time period.

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

[0111] In some embodiments of the present application, in the above device, the first modulation unit 720 is configured to draw the noise spectrograms of the noise time domain signals 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 device, a second modulation unit 730 is configured to form the noise frequency domain vectors of each user node in each time period by using all the energy amplitudes in the noise spectrograms; 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 device, the second modulation unit 730 is configured to calculate the dispersion degree and the mean value of the noise difference degrees between each user node and the remaining user nodes in all time periods respectively; and use the reciprocal of the product of the dispersion degree and the mean value as the channel coincidence degree between each user node and the remaining user nodes.

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

[0115]

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

[0117] In some embodiments of the present application, in the above device, the third modulation unit 740 is configured to use the frequency corresponding to the minimum element value in the colored noise signal of each of the user nodes in the noise spectrogram as the optimal carrier frequency of each of the user nodes on the current day; based on the optimal carrier frequency, use a signal modulation algorithm to modulate the digital bit stream of each of the user nodes on the current day, output a modulation signal, send the modulation signal to the power line for transmission, and then use a signal demodulation algorithm to output a digital bit stream.

[0118] It should be noted that the power line carrier modulation device for a carrier chip in the present application can implement the foregoing power line carrier modulation method for a carrier chip one by one, and details are not described herein again.

[0119] Based on the same inventive concept as the above method, an embodiment of the present application further provides a power line carrier modulation system for a carrier chip. 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. When the processor executes the computer program, the steps of any one of the above 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 according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 at least a part of the steps in

[0121] can 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 alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0122] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made. Therefore, any simple modification, equivalent change, and decoration made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application all 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; Extracting the colored noise signal of each user node based on the noise spectrum diagram of all time periods between each user node and other user nodes and the channel overlap; and determining the optimal carrier frequency of each user node on that day based on the colored noise signal, and performing carrier communication on the communication signal of each user node; 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.

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 colored noise signal is calculated as follows: 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.

7. 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.

8. 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; A 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 determine the optimal carrier frequency of each user node on the day based on the colored noise signal, and perform carrier communication on the communication signal of each user node; The second modulation unit is used to respectively calculate the discrete degree and the mean value of the noise difference between each user node and the remaining user nodes in all time periods; and use the inverse of the product of the discrete degree and the mean value as the channel overlap between each user node and the remaining user nodes.

9. 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 7 are implemented.

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