CN101944935A - Self-adaptive adjustment system and method for carrier communication of low-voltage power line - Google Patents

Abstract

The invention provides a self-adaptive adjustment system and a method for the carrier communication of a low-voltage power line for automatically adjusting key parameters of the spread spectrum carrier communication of a power line so as to improve the carrier communication reliability of the power line and reduce the bit error rate. The self-adaptive adjustment system comprises an input signal conditioning module, a sampling and filtering module, a link quality detection module, a signal intensity detection module, a comprehensive error detection module, a self-adaptive algorithm adjustment module and a symbol decision module, wherein the self-adaptive algorithm adjustment module comprises a fuzzy normalization part, a fuzzy rule part, an inference engine part and a decision threshold value part. In the invention, a spread spectrum communication decision threshold value is automatically tracked and adjusted through checking the parameters of the link quality, the signal intensity, the comprehensive error, and the like of the communication system so as to ensure that the performance of the communication system reaches the optimum, i.e. the communication success rate reaches a maximum value under the current working condition.

Description

The self-adapted adjustment system of low-voltage powerline carrier communication and method

Technical field

The present invention relates to be used for the system and method that the self adaptation of low-voltage powerline carrier communication is adjusted.

Background technology

Low-voltage powerline carrier communication is a kind of communication mode the most basic in the power communication system, it is to utilize power line as transmission channel, do not need the independent construction of line and maintenance line, and power circuit is firm in structure, therefore power line carrier communication also is a distinctive communication mode in the electric power system, has been widely used in fields such as centralized automatic meter-reading, Smart Home, intelligent building at present.Yet low-voltage power line network configuration and load complexity, work under bad environment, signal attenuation are big, the low-voltage power line interchannel noise disturb and the time become that to decay be its intrinsic defective, this has caused, and the power line transmission data rate is lower, reliability is also poor, has seriously restricted applying of power-line carrier communication.Country is promoting the construction of intelligent grid energetically at present, and low-voltage carrier communication will be played a greater and greater role as a kind of important technical that solves " last kilometer " problem that exists in the intelligent grid.Therefore solve the reliability of low-voltage powerline carrier communication, the key that the raising traffic rate becomes development low-voltage carrier communication technology.

Spread spectrum communication is the widely used a kind of communication technology in present power line carrier communication field.Though it is strong that this technology has an antijamming capability, good confidentiality, anti-fading, the anti-multipath interference performance is strong, have the multiple access ability, be easy to realize advantages such as Code Division Multiple Access (CDMA), yet also not fully up to expectations in actual application, existence communication success rate is not high, traffic rate waits problem more slowly.

Summary of the invention

The purpose of this invention is to provide a kind of self-adapted adjustment system and method for low-voltage powerline carrier communication, the key parameter of power line spread spectrum carrier communication is adjusted automatically,, reduce the error rate to improve the power line carrier communication reliability.

For achieving the above object, technical scheme of the present invention is as follows: a kind of self-adapted adjustment system of low voltage power line carrier communication, it is characterized in that, comprising: the input signal conditioning module converts input signal to standard signal that collecting device can be discerned by operations such as amplification, filtering; Sampling and filtration module will the time be gone up, continuous analog signal all on the amplitude, and the time that converts to is gone up continuous discrete analog signal on discrete, the amplitude, and carries out digital Filtering Processing; The link-quality detection module detects current communication link quality, and testing result is input to Adaptive adjusting algorithm; The signal strength detection module detects the signal strength signal intensity under the current environment, and testing result is input to Adaptive adjusting algorithm; Comprehensive error detection modules detects parameter such as the final error rate, communication success rate in the current communication system, and testing result is input to the Adaptive adjusting algorithm module; The Adaptive adjusting algorithm module, according to the link-quality that dynamically detects, signal strength signal intensity, these parameters of composition error, Automatic Optimal is adjusted the threshold value of symbol judgement; And the symbol judgement module, according to detected signal, the combined symbol decision threshold rules out traffic symbols.

Above-mentioned Adaptive adjusting algorithm module comprises: fuzzy normalization module, the detected unit different data of dimension are converted to nondimensional data, and carry out Fuzzy processing simultaneously; The fuzzy rule module comprises a series of fuzzy inference rules, for the inference machine module provides the reasoning foundation; The inference machine module is carried out fuzzy reasoning according to fuzzy rule, determines The reasoning results, i.e. the fuzzy language value of optimum decision threshold value adjustment amount; Decision-making decision threshold module, the fuzzy language value of the decision threshold adjustment amount that inference machine is definite carries out the defuzzification processing, but is transformed into the symbol judgement threshold value of practical application.

A kind of self-adapting regulation method of low voltage power line carrier communication is characterized in that, comprising: (1) converts input signal to standard signal that collecting device can be discerned by operations such as amplification, filtering; (2) will the time go up, all continuous standard signal on the amplitude, the time that converts to is gone up continuous discrete analog signal on discrete, the amplitude, and carries out digital Filtering Processing; (3) according to detected signal, the combined symbol decision threshold rules out communications data symbols; Wherein, by detecting the signal strength signal intensity under current communication link quality, the current environment, the composition error in the current communication system, and testing result is input to Adaptive adjusting algorithm, Automatic Optimal is adjusted the threshold value of symbol judgement.

Self-adapted adjustment system and method that the present invention proposes, parameters such as link-quality, signal strength signal intensity and comprehensive mistake by the check communication system, from motion tracking and adjust the spread spectrum communication decision threshold, make communication system performance reach optimum, the success rate of promptly communicating by letter is issued to peak at the work at present environment.Solve the not high problem of carrier wave spread spectrum communication communication success rate, improved the communication success rate.

Description of drawings

Fig. 1 is the principle schematic of carrier communication self-adapting regulation method of the present invention.

Fig. 2 is input signal and standard signal schematic diagram.

Fig. 3 is the sampling process schematic diagram.

Fig. 4 is an Adaptive adjusting algorithm module principle block diagram.

The invention will be further described below in conjunction with drawings and Examples.

Embodiment

As shown in Figure 1, the self-adapted adjustment system of the low voltage power line carrier communication that present embodiment provides comprises seven functional modules, illustrates respectively below in conjunction with accompanying drawing.

The input signal conditioning module converts input signal to standard signal that collecting device (AD converting unit) can be discerned by amplification, filtering operation; This functional module is realized by hardware circuit, finishes the signal condition function by integrated transporting discharging, RC bandwidth-limited circuit.Fig. 2 a is the input signal schematic diagram, and Fig. 2 b is through the standard signal schematic diagram after amplification, the Filtering Processing.

Sampling and filtration module, with the above-mentioned time go up, all continuous standard signal on the amplitude, the time that converts to is gone up continuous discrete analog signal on discrete, the amplitude, and carries out digital Filtering Processing.Fig. 3 a is an analog signal, and Fig. 3 b is the discrete analog signal behind the equal interval sampling.According to nyquist sampling theorem, sample frequency will be the twice of signal highest frequency at least, and the present invention adopts sampling of 4 frequencys multiplication and Tchebyshev band pass filter to carry out digital filtering in the specific implementation.

The link-quality detection module detects current communication link quality, and testing result is input to Adaptive adjusting algorithm; Link-quality detects and comprises three steps: digital frequency discrimination, digital demodulation, related operation, the related operation result is link-quality.

The signal strength detection module detects the signal strength signal intensity under the current environment, and testing result is input to Adaptive adjusting algorithm; Signal strength detection adopts sliding window formula computational methods, and the data that sample by the time integration, are promptly obtained current demand signal intensity.

Comprehensive error detection modules detects the comprehensive mistake of current communication system, and comprehensive mistake comprises the error rate and communication success rate in the present embodiment, and testing result is input to the Adaptive adjusting algorithm module.The error rate detects by the method for code element coupling, i.e. the code element matching rate; The communication success rate detects by frame check, if frame check mistake or the imperfect then communication failure of frame are once, otherwise then communicates by letter successfully once, and number of communications in statistics a period of time and communication number of success, and then calculate the communication success rate.Take all factors into consideration the error rate and communication success rate, give the error rate and the weight of success rate of communicating by letter respectively, promptly obtain comprehensive error rate.

The Adaptive adjusting algorithm module, according to the link-quality that dynamically detects, signal strength signal intensity, comprehensive these parameters of mistake, Automatic Optimal is adjusted the threshold value of symbol judgement.

The symbol judgement module, according to detected signal, the combined symbol decision threshold rules out traffic symbols.

As shown in Figure 4, in the present embodiment, the Adaptive adjusting algorithm module comprises four submodules, describes in detail respectively below.

Fuzzy normalization module:, carry out Fuzzy processing simultaneously, so that carry out follow-up fuzzy reasoning because the unit dimension difference of detected data need be converted to nondimensional data.Following normalization formula is adopted in the normalization of data, and normalization is in the scope of [1 1]: $y=\frac{Y-(b+a)/2}{(b-a)/2}$ Wherein, Y is an input variable, and [a, b] is the range ability of Y, and y is the output of normalization.

Data after the normalization will be carried out Fuzzy processing, divide according to each fuzzy class that detects data (link-quality, signal strength signal intensity, composition error) respectively, obtain the fuzzy language value E of each data volume respectively _LQU, E _RSSI, E _FCSDivide no aliasing, no neutral gear for the fuzzy domain that makes variable Y in addition, zero span is divided and will be guaranteed control precision simultaneously, and present embodiment obfuscation rule is as follows: fuzzy class is divided and is adopted inhomogeneous stepping, is divided into 7 class.And design zero span interval value minimum, along with class increases, corresponding interval value strengthens successively. $E_{\mathrm{LQV}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$ $E_{\mathrm{RSSI}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$ $E_{\mathrm{FCS}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$ In the following formula: sgn (y) is the symbol of peek value y.

The fuzzy rule module: comprising a series of fuzzy inference rules, for inference machine provides the reasoning foundation, is the core of Adaptive adjusting algorithm; Fuzzy control rule is the foundation of fuzzy control, and its form is as follows: 1 AND condition 2...AND condition n THEN conclusion or the action of IF condition.

The fuzzy rule that present embodiment adopted includes three conditions, is respectively link-quality condition, signal strength conditions and composition error condition, the fuzzy language value E that the conclusion of fuzzy rule is adjusted for the symbol judgement threshold value _ValList a rule below: IF E _FCS=0 AND E _LQU=-2 AND E _RSSI=-1 THEN E _Val=-2; With E _FCS=0 o'clock series of rules is summarised in together, has just obtained E as shown in the table _FCS=0 o'clock, by E _RSSIAnd E _LQUInfer E _ValInference rule.E is worked as in same also can putting in order out _FCSInference rule during for other numerical value.

Inference machine module: carry out the fuzzy reasoning computing according to fuzzy rule, determine the fuzzy language value of the adjustment amount of The reasoning results (being the optimum decision threshold value); Decision-making decision threshold module: the fuzzy language value that inference machine is determined carries out the defuzzification processing, but is transformed into the symbol judgement threshold value of practical application.The process of defuzzification adopts following formula: In the following formula: V _N+1: the symbol judgement threshold value V when next time adjudicating _N: the symbol judgement threshold value V during this judgement _T: symbol judgement upper threshold V _B: symbol judgement threshold value lower limit V _P: the adjustment step-length E of symbol judgement threshold value _Val: the The reasoning results of inference machine output, the fuzzy class of decision threshold, span [3,3] E _MAX: the fuzzy class maximum of decision threshold, get among the present invention and illustrate above-mentioned adaptive fuzzy adjustment algorithm below " 3 ".

With the link-quality is example explanation normalization and fuzzification process.The span of supposing link-quality is [10 60], i.e. a=10, b=60.Certain detected link-quality of the moment is 45, promptly imports Y=45, and this moment, the normalization of link-quality was exported: $y=\frac{Y-(b+a)/2}{(b-a)/2}=\frac{47-(60+10)/2}{(60-10)/2}=\frac{12}{25}=0.48$ So the fuzzy language value of link-quality is: $E_{\mathrm{LQV}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.=2*\mathrm{sgn}\left(0.48\right)=2$ The following describes fuzzy reasoning process.Suppose to obtain the fuzzy language value of link-quality, signal strength signal intensity, three data of composition error, numerical value is as follows respectively: E _LQU=2, E _PSSI=1, E _FCS=0; By fuzzy inference rule, promptly look into E _FCS=0 pairing fuzzy reasoning table gets the fuzzy language value that decision threshold is adjusted: E _Val=2.

The following describes the defuzzification process.Suppose that corresponding data is as follows: the symbol judgement threshold value V during this judgement _N=56; Symbol judgement upper threshold V _T=70; Symbol judgement threshold value lower limit V _B=50; The adjustment step-length V of symbol judgement threshold value _P=3; Get by the defuzzification formula: $V_{N+1}=V_N+\frac{E_{\mathrm{val}}}{E_{\max }}*V_P=56+\frac{2}{3}*3=58$ Promptly obtain optimum decision threshold value V next time _N+1=58.

If above-mentioned defuzzification formula obtains optimum decision threshold value V _N+1〉=V _T, then get V _N+1=V _T=70, if above-mentioned defuzzification formula obtains optimum decision threshold value V _N+1≤ V _B, then get V _N+1=V _B=50.

Above embodiment only is fully open unrestricted the present invention, for example, three features that the foregoing description is selected: the composition error in the signal strength signal intensity under current communication link quality, the current environment, the current communication system, only think and necessary and important feature should not limit the feature that adds other for present embodiment; In like manner, described comprehensive mistake should not limit the factor that also has other yet except that comprising the error rate and communication success rate, can depend on the circumstances; In addition, the setting of the parameter in the specific algorithm, threshold value, condition only is the preferred embodiment under the application-specific.So, replace based on any non-creativeness of keynote idea of the present invention, should belong to the scope that the present invention discloses.

Claims (13)

1. the self-adapted adjustment system of a low voltage power line carrier communication is characterized in that, comprising:

The input signal conditioning module converts input signal to standard signal that collecting device can be discerned by operations such as amplification, filtering;

Sampling and filtration module will the time be gone up, continuous analog signal all on the amplitude, and the time that converts to is gone up continuous discrete analog signal on discrete, the amplitude, and carries out digital Filtering Processing;

The link-quality detection module detects current communication link quality, and testing result is input to Adaptive adjusting algorithm;

The signal strength detection module detects the signal strength signal intensity under the current environment, and testing result is input to Adaptive adjusting algorithm;

Comprehensive error detection modules detects parameter such as the final error rate, communication success rate in the current communication system, and testing result is input to the Adaptive adjusting algorithm module;

The Adaptive adjusting algorithm module, according to the link-quality that dynamically detects, signal strength signal intensity, these parameters of composition error, Automatic Optimal is adjusted the threshold value of symbol judgement;

The symbol judgement module, according to detected signal, the combined symbol decision threshold rules out communications data symbols.

2. the self-adapted adjustment system of low voltage power line carrier communication according to claim 1 is characterized in that, described Adaptive adjusting algorithm module comprises:

Fuzzy normalization module is converted to nondimensional data with the detected unit different data of dimension, carries out Fuzzy processing simultaneously;

The fuzzy rule module comprises a series of fuzzy inference rules, for the inference machine module provides the reasoning foundation;

The inference machine module is carried out fuzzy reasoning according to fuzzy rule, determines the fuzzy language value of optimum decision threshold value adjustment amount;

Decision-making decision threshold module, the fuzzy language value of the decision threshold adjustment amount that inference machine is definite carries out the defuzzification processing, but is transformed into the symbol judgement threshold value of practical application.

3. the self-adapting regulation method of a low voltage power line carrier communication is characterized in that, comprising:

(1) converts input signal to standard signal that collecting device can be discerned by operations such as amplification, filtering;

(2) will the time go up, all continuous standard signal on the amplitude, the time that converts to is gone up continuous discrete analog signal on discrete, the amplitude, and carries out digital Filtering Processing;

(3) according to detected signal, the combined symbol decision threshold rules out traffic symbols; Wherein, by detecting the signal strength signal intensity under current communication link quality, the current environment, the composition error in the current communication system, and testing result is input to Adaptive adjusting algorithm, Automatic Optimal is adjusted the threshold value of symbol judgement.

4. the self-adapting regulation method of low voltage power line carrier communication according to claim 3 is characterized in that: adopt quadruple sampling and Tchebyshev band pass filter to carry out digital filtering when in the step (2) continuous signal being converted into discrete signal.

5. the self-adapting regulation method of low voltage power line carrier communication according to claim 3, it is characterized in that: detect current communication link quality by three steps, these three steps comprise: digital frequency discrimination, digital demodulation, related operation, the related operation result is link-quality.

6. the self-adapting regulation method of low voltage power line carrier communication according to claim 3 is characterized in that: adopt sliding window formula computational methods, the data that sample by the time integration, are promptly obtained the signal strength signal intensity under the current environment.

7. the self-adapting regulation method of low voltage power line carrier communication according to claim 3 is characterized in that: described comprehensive mistake comprises the error rate and communication success rate; The error rate detects by the method for code element coupling; The communication success rate detects by frame check, if frame check mistake or the imperfect then communication failure of frame are once, otherwise then communicates by letter successfully once, and number of communications in statistics a period of time and communication number of success, and then calculate the communication success rate; Take all factors into consideration the error rate and communication success rate, give the error rate and the weight of success rate of communicating by letter respectively, promptly obtain comprehensive error rate.

8. according to the self-adapting regulation method of any described low voltage power line carrier communication of claim 3 to 7, it is characterized in that: the described threshold value that testing result is input to Adaptive adjusting algorithm Automatic Optimal adjustment symbol judgement, specifically comprise: 1. the signal strength signal intensity under detected current communication link quality, the current environment, the data of composition error in the current communication system are converted to nondimensional data, carry out the normalizing Fuzzy processing simultaneously; 2. provide a series of fuzzy inference rules, as the reasoning foundation; 3. carry out fuzzy reasoning according to fuzzy rule, determine the fuzzy language value of optimum decision threshold value adjustment amount; 4. the fuzzy language value of the decision threshold adjustment amount that reasoning is determined carries out the defuzzification processing, but is transformed into the symbol judgement threshold value of practical application.

9. the self-adapting regulation method of low voltage power line carrier communication according to claim 8 is characterized in that: following normalization formula is adopted in the normalization of described data, and normalization is in the scope of [1 1]:

$y=\frac{Y-(b+a)/2}{(b-a)/2}$

Wherein, Y is an input variable, and [a, b] is the range ability of Y, and y is the output of normalization.

10. the self-adapting regulation method of low voltage power line carrier communication according to claim 9, it is characterized in that: in the described Fuzzy processing of data, divide according to the fuzzy class of the composition error in the signal strength signal intensity under current communication link quality, the current environment, the current communication system respectively, obtain the fuzzy language value E of each data volume respectively _LQU, E _RSSI, E _FCSThe obfuscation rule is as follows: fuzzy class is divided and is adopted inhomogeneous stepping, is divided into 7 class, and design zero span interval value minimum, and along with class increases, corresponding interval value strengthens successively.

11. the self-adapting regulation method of low voltage power line carrier communication according to claim 10 is characterized in that: described obfuscation rule is as follows:

$E_{\mathrm{LQU}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$ $E_{\mathrm{RSSI}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$

$E_{\mathrm{FCS}}=\left\{\begin{array}{cc}3\mathrm{sgn}\left(y\right)& 1\≥\left|y\right|\≥0.7\\ 2\mathrm{sgn}\left(y\right)& 0.7>\left|y\right|\≥0.4\\ 1\mathrm{sgn}\left(y\right)& 0.4>\left|y\right|\≥0.1\\ 0& \left|y\right|\≤0.1\end{array}\right.$

In the following formula: sgn (y) is the symbol of peek value y.

12. the self-adapting regulation method of low voltage power line carrier communication according to claim 11 is characterized in that: described fuzzy inference rule form is as follows:

IF E _FCS=? AND E _LQU=? AND E _RSSI=? THEN E _Val=? E _ValFuzzy language value for the adjustment of symbol judgement threshold values.

13. the self-adapting regulation method of low voltage power line carrier communication according to claim 12 is characterized in that: the process of described defuzzification adopts following formula:

In the following formula: V _N+1: the symbol judgement threshold value when next time adjudicating; V _N: the symbol judgement threshold value during this judgement; V _T: the symbol judgement upper threshold; V _B: symbol judgement threshold value lower limit; V _P: the adjustment step-length of symbol judgement threshold value; E _Val: the The reasoning results of inference machine output, the fuzzy class of decision threshold, span [3,3]; E _MAX: the fuzzy class maximum of decision threshold, get " 3 ".

Images