CN111541635A - PLC signal filtering method and system using t distribution - Google Patents

PLC signal filtering method and system using t distribution Download PDF

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Publication number
CN111541635A
CN111541635A CN202010463465.6A CN202010463465A CN111541635A CN 111541635 A CN111541635 A CN 111541635A CN 202010463465 A CN202010463465 A CN 202010463465A CN 111541635 A CN111541635 A CN 111541635A
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signal sequence
mth
formula
sequence
block
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翟明岳
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Guangdong University of Petrochemical Technology
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Guangdong University of Petrochemical Technology
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L25/03178—Arrangements involving sequence estimation techniques
    • H04L25/03305—Joint sequence estimation and interference removal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H04B1/1027—Means associated with receiver for limiting or suppressing noise or interference assessing signal quality or detecting noise/interference for the received signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2203/00—Indexing scheme relating to line transmission systems
    • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
    • H04B2203/5462—Systems for power line communications
    • H04B2203/5491—Systems for power line communications using filtering and bypassing

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  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

The embodiment of the invention discloses a PLC signal filtering method and a system utilizing t distribution, wherein the method comprises the following steps: step 101, acquiring a signal sequence S acquired according to a time sequence; step 102 finds the number of blocks NBLOCK(ii) a Step 103 generates an mth block signal sequence sm(ii) a Step 104, creating an iteration control parameter k and assigning the iteration control parameter k as 0; solving the initial value h of the mth block filtering sequence h0Step 105, adding 1 to the value of the iterative control parameter k, and calculating the impulse factor αk(ii) a Step 106, the kth step value h of the mth t distribution sequence h is obtainedk(ii) a Step 107 obtains an approximation error e, where e is ═ hk‑hk‑1L, |; step 108, judging whether the approximation error e is larger than or equal to a preset threshold value0Obtaining a first judgment result step; step 109 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure DDA0002511843010000011
Figure DDA0002511843010000012

Description

PLC signal filtering method and system using t distribution
Technical Field
The invention relates to the field of communication, in particular to a PLC signal filtering method and system.
Background
Compared with various wired communication technologies, the power line communication has the advantages of no need of rewiring, easiness in networking and the like, and has wide application prospect. The power line communication technology is divided into Narrowband over power line (NPL) and Broadband over power line (BPL); the narrow-band power line communication refers to a power line carrier communication technology with the bandwidth limited between 3k and 500 kHz; the power line communication technology includes a prescribed bandwidth (3148.5kHz) of european CENELEC, a prescribed bandwidth (9 to 490kHz) of the Federal Communications Commission (FCC) in the united states, a prescribed bandwidth (9 to 450kHz) of the Association of Radio Industries and Businesses (ARIB) in japan, and a prescribed bandwidth (3 to 500kHz) in china. The narrow-band power line communication technology mainly adopts a single carrier modulation technology, such as a PSK technology, a DSSS technology, a Chirp technology and the like, and the communication speed is less than 1 Mbits/s; the broadband power line communication technology refers to a power line carrier communication technology with a bandwidth limited between 1.6 and 30MHz and a communication rate generally above 1Mbps, and adopts various spread spectrum communication technologies with OFDM as a core.
Although power line communication systems are widely used and the technology is relatively mature, a large number of branches and electrical devices in the power line communication system generate a large amount of noise in the power line channel; random impulse noise has high randomness and high noise intensity, and seriously damages a power line communication system, so that the technology for inhibiting the random impulse noise is always the key point for the research of scholars at home and abroad; and the noise model does not fit into a gaussian distribution. Therefore, the traditional communication system designed aiming at the gaussian noise is not suitable for a power line carrier communication system any more, and a corresponding noise suppression technology must be researched to improve the signal-to-noise ratio of the power line communication system, reduce the bit error rate and ensure the quality of the power line communication system.
In practical applications, some simple non-linear techniques are often applied to eliminate power line channel noise, such as Clip-ping, Blanking and Clipping/Blanking techniques, but these research methods all have to work well under a certain signal-to-noise ratio condition, and only consider the elimination of impulse noise, in a power line communication system, some commercial power line transmitters are characterized by low transmission power, and in some special cases, the transmission power may be even lower than 18w, so that in some special cases, signals are submerged in a large amount of noise, resulting in a low signal-to-noise ratio condition of the power line communication system.
Disclosure of Invention
With the application and popularization of nonlinear electrical appliances, background noise in a medium and low voltage power transmission and distribution network presents obvious non-stationarity and non-Gaussian characteristics, a common low-pass filter is difficult to achieve an ideal filtering effect in a non-stationarity and non-Gaussian noise environment, the non-stationarity and non-Gaussian noise is difficult to filter, and the performance of a PLC communication system is seriously influenced. .
The invention aims to provide a PLC signal filtering method and a system utilizing t distribution. The method has good noise filtering performance and is simple in calculation.
In order to achieve the purpose, the invention provides the following scheme:
a PLC signal filtering method using a t-profile, comprising:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102 finds the number of blocks NBLOCKThe formula is obtained as
Figure BDA0002511840990000021
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure BDA0002511840990000022
is the variance of the signal sequence S;
Figure BDA0002511840990000023
represents lower rounding; n is the length of the signal sequence S;
step 103 generates an mth block signal sequence smThe formula is obtained as
Figure BDA0002511840990000024
Figure BDA0002511840990000025
Wherein, m is the serial number of the block signal sequence, and the value range is m ═ 1,2, ·, NBLOCK；
Figure BDA00025118409900000221
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure BDA00025118409900000222
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure BDA00025118409900000220
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure BDA0002511840990000026
Figure BDA0002511840990000027
Representing upper rounding;
step 104, creating an iteration control parameter k and assigning the iteration control parameter k as 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
Step 105, adding 1 to the value of the iterative control parameter k, and solving the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
Step 106, the kth step value h of the mth t distribution sequence h is obtainedkThe formula is obtained as
Figure BDA0002511840990000028
Figure BDA0002511840990000029
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure BDA00025118409900000210
pijIs a first adjacent vector, and the calculation formula is
Figure BDA00025118409900000211
Figure BDA00025118409900000212
qijIs a second adjacent vector, and the calculation formula is
Figure BDA00025118409900000213
Figure BDA00025118409900000214
Figure BDA00025118409900000215
For the mth block signal sequence smI is the first serial number of the element, and the value range is i ═ 1,2, ·, Ns；
Figure BDA00025118409900000216
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j ═ 1,2, ·, Ns；
Step 107 obtains an approximation error e, where e is ═ hk-hk-1|；
Step 108, judging whether the approximation error e is larger than or equal to a preset threshold value0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to the step 105, the step 106, the step 107 and the step 108; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Step 109 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure BDA00025118409900000223
Figure BDA00025118409900000224
A PLC signal filtering system using a t-profile, comprising:
the module 201 acquires a signal sequence S acquired in time sequence;
module 202 finds the number of blocks NBLOCKThe formula is obtained as
Figure BDA00025118409900000217
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure BDA00025118409900000218
is the variance of the signal sequence S;
Figure BDA00025118409900000219
represents lower rounding; n is the length of the signal sequence S;
the module 203 generates the mth block signal sequence smThe formula is obtained as
Figure BDA0002511840990000031
Figure BDA0002511840990000032
Wherein, m is the serial number of the block signal sequence, and the value range is m ═ 1,2, ·, NBLOCK；
Figure BDA00025118409900000314
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure BDA00025118409900000315
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure BDA00025118409900000316
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure BDA0002511840990000033
Figure BDA0002511840990000034
Representing upper rounding;
the module 204 creates an iteration control parameter k and assigns a value of 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
The iterative control parameter k of block 205 is incremented by 1 to find the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
The module 206 calculates the kth step h of the mth t distribution sequence hkThe formula is obtained as
Figure BDA0002511840990000035
Figure BDA0002511840990000036
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure BDA0002511840990000037
pijIs a first adjacent vector, and the calculation formula is
Figure BDA0002511840990000038
Figure BDA0002511840990000039
qijIs a second adjacent vector, and the calculation formula is
Figure BDA00025118409900000310
Figure BDA00025118409900000311
Figure BDA00025118409900000312
For the mth block signal sequence smI is the first serial number of the element, and the value range is i ═ 1,2, ·, Ns；
Figure BDA00025118409900000313
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j ═ 1,2, ·, Ns；
The module 207 finds the approximation error e, which is given by the equation e ═ hk-hk-1|；
Module 208 determines whether the approximation error e is greater than or equal to a predetermined threshold0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to said module 201, said module 202, said module 203 and said module 204; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Module 209 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure BDA00025118409900000317
Figure BDA00025118409900000318
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
with the application and popularization of nonlinear electrical appliances, background noise in a medium and low voltage power transmission and distribution network presents obvious non-stationarity and non-Gaussian characteristics, a common low-pass filter is difficult to achieve an ideal filtering effect in a non-stationarity and non-Gaussian noise environment, the non-stationarity and non-Gaussian noise is difficult to filter, and the performance of a PLC communication system is seriously influenced. .
The invention aims to provide a PLC signal filtering method and a system utilizing t distribution. The method has good noise filtering performance and is simple in calculation.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic flow diagram of the process of the present invention;
FIG. 2 is a schematic flow chart of the system of the present invention;
FIG. 3 is a flow chart illustrating an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
FIG. 1 is a flow chart illustrating a PLC signal filtering method using t-distribution
Fig. 1 is a flow chart illustrating a PLC signal filtering method using a t-profile according to the present invention. As shown in fig. 1, the PLC signal filtering method using t-profile specifically includes the following steps:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102 finds the number of blocks NBLOCKThe formula is obtained as
Figure BDA0002511840990000041
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure BDA0002511840990000042
is the variance of the signal sequence S;
Figure BDA0002511840990000043
represents lower rounding; n is the length of the signal sequence S;
step 103 generates an mth block signal sequence smThe formula is obtained as
Figure BDA0002511840990000044
Figure BDA0002511840990000045
Wherein, m is the serial number of the block signal sequence, and the value range is m ═ 1,2, ·, NBLOCK；
Figure BDA00025118409900000410
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure BDA00025118409900000411
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure BDA00025118409900000412
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure BDA0002511840990000046
Figure BDA0002511840990000047
Representing upper rounding;
step 104, creating an iteration control parameter k and assigning the iteration control parameter k as 0; obtaining an initial value h of the mth t distribution sequence h0To find outTake the formula as h0＝sm；
Step 105, adding 1 to the value of the iterative control parameter k, and solving the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
Step 106, the kth step value h of the mth t distribution sequence h is obtainedkThe formula is obtained as
Figure BDA0002511840990000048
Figure BDA0002511840990000049
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure BDA0002511840990000051
pijIs a first adjacent vector, and the calculation formula is
Figure BDA0002511840990000052
Figure BDA0002511840990000053
qijIs a second adjacent vector, and the calculation formula is
Figure BDA0002511840990000054
Figure BDA0002511840990000055
Figure BDA0002511840990000056
For the mth block signal sequence smI is the first serial number of the element, and the value range is i ═ 1,2, ·, Ns；
Figure BDA0002511840990000057
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j ═ 1,2, ·, Ns；
Step 107 obtains an approximation error e, where e is ═ hk-hk-1|；
Step 108, judging whether the approximation error e is larger than or equal to a preset threshold value0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to the step 105, the step 106, the step 107 and the step 108; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Step 109 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure BDA00025118409900000520
Figure BDA00025118409900000521
FIG. 2 structural intention of a PLC signal filtering system using t-distribution
Fig. 2 is a schematic structural diagram of a PLC signal filtering system using t-profile according to the present invention. As shown in fig. 2, the PLC signal filtering system using t-profile includes the following structure:
the module 201 acquires a signal sequence S acquired in time sequence;
module 202 finds the number of blocks NBLOCKThe formula is obtained as
Figure BDA0002511840990000058
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure BDA0002511840990000059
is the variance of the signal sequence S;
Figure BDA00025118409900000510
represents lower rounding; n isThe length of the signal sequence S;
the module 203 generates the mth block signal sequence smThe formula is obtained as
Figure BDA00025118409900000511
Figure BDA00025118409900000512
Wherein, m is the serial number of the block signal sequence, and the value range is m ═ 1,2, ·, NBLOCK；
Figure BDA00025118409900000517
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure BDA00025118409900000518
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure BDA00025118409900000519
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure BDA00025118409900000513
Figure BDA00025118409900000514
Representing upper rounding;
the module 204 creates an iteration control parameter k and assigns a value of 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
The iterative control parameter k of block 205 is incremented by 1 to find the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
The module 206 calculates the kth step h of the mth t distribution sequence hkThe formula is obtained as
Figure BDA00025118409900000515
Figure BDA00025118409900000516
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure BDA0002511840990000061
pijIs a first adjacent vector, and the calculation formula is
Figure BDA0002511840990000062
Figure BDA0002511840990000063
qijIs a second adjacent vector, and the calculation formula is
Figure BDA0002511840990000064
Figure BDA0002511840990000065
Figure BDA0002511840990000066
For the mth block signal sequence smI is the first serial number of the element, and the value range is i ═ 1,2, ·, Ns；
Figure BDA0002511840990000067
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j ═ 1,2, ·, Ns；
The module 207 finds the approximation error e, which is given by the equation e ═ hk-hk-1|；
Module 208 determines whether the approximation error e is greater than or equal to a predetermined threshold0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to said module 201, said module 202, said module 203 and said module 204; until the first judgment result shows the approachThe near error e is less than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Module 209 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure BDA00025118409900000617
Figure BDA00025118409900000618
The following provides an embodiment for further illustrating the invention
FIG. 3 is a flow chart illustrating an embodiment of the present invention. As shown in fig. 3, the method specifically includes the following steps:
step 301, acquiring a signal sequence S acquired according to a time sequence;
step 302 finds the number of block NBLOCKThe formula is obtained as
Figure BDA0002511840990000068
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure BDA0002511840990000069
is the variance of the signal sequence S;
Figure BDA00025118409900000610
represents lower rounding; n is the length of the signal sequence S;
step 303 generates the mth block signal sequence smThe formula is obtained as
Figure BDA00025118409900000611
Figure BDA00025118409900000612
Wherein, m is the serial number of the block signal sequence, and the value range is m ═ 1,2, ·, NBLOCK；
Figure BDA00025118409900000619
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure BDA00025118409900000620
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure BDA00025118409900000621
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure BDA00025118409900000613
Figure BDA00025118409900000614
Representing upper rounding;
step 304, creating an iteration control parameter k and assigning the iteration control parameter k as 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
Step 305, adding 1 to the value of the iterative control parameter k, and solving the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
Step 306, calculating the kth step value h of the mth t distribution sequence hkThe formula is obtained as
Figure BDA00025118409900000615
Figure BDA00025118409900000616
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure BDA0002511840990000071
pijIs a first adjacent vector, and the calculation formula is
Figure BDA0002511840990000072
Figure BDA0002511840990000073
qijIs a second adjacent vector, and the calculation formula is
Figure BDA0002511840990000074
Figure BDA0002511840990000075
Figure BDA0002511840990000076
For the mth block signal sequence smI is the first serial number of the element, and the value range is i ═ 1,2, ·, Ns；
Figure BDA0002511840990000077
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j ═ 1,2, ·, Ns；
Step 307 obtains an approximation error e, where the equation is e ═ hk-hk-1|；
Step 308, determining whether the approximation error e is greater than or equal to a preset threshold0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to said step 305, said step 306, said step 307 and said step 308; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Step 309 records the noise filtered signal sequence SNEWIs concretely provided with
Figure BDA0002511840990000078
Figure BDA0002511840990000079
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is simple because the system corresponds to the method disclosed by the embodiment, and the relevant part can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (2)

1. The PLC signal filtering method using t-distribution is characterized by comprising the following steps:
step 101, acquiring a signal sequence S acquired according to a time sequence;
step 102 finds the number of blocks NBLOCKThe formula is obtained as
Figure FDA0002511840980000011
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure FDA0002511840980000012
is the variance of the signal sequence S;
Figure FDA0002511840980000013
represents lower rounding; n is the length of the signal sequence S;
step 103 generates an mth block signal sequence smThe formula is obtained as
Figure FDA0002511840980000014
Figure FDA0002511840980000015
Wherein, m is the serial number of the block signal sequence, and the value range is m-1, 2, …, NBLOCK；
Figure FDA00025118409800000117
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure FDA00025118409800000118
is the (m-1) N th of the signal sequence Ss+2 elements;
Figure FDA00025118409800000119
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure FDA0002511840980000016
Figure FDA0002511840980000017
Representing upper rounding;
step 104, creating an iteration control parameter k and assigning the iteration control parameter k as 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
Step 105, adding 1 to the value of the iterative control parameter k, and solving the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
Step 106, the kth step value h of the mth t distribution sequence h is obtainedkThe formula is obtained as
Figure FDA0002511840980000018
Figure FDA0002511840980000019
Wherein h isk-1Is that it isThe step k-1 value of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure FDA00025118409800000110
pijIs a first adjacent vector, and the calculation formula is
Figure FDA00025118409800000111
qijIs a second adjacent vector, and the calculation formula is
Figure FDA00025118409800000112
Figure FDA00025118409800000113
For the mth block signal sequence smI is the first serial number of the element, and the value range is that i is 1,2, …, Ns；
Figure FDA00025118409800000114
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j equals to 1,2, …, Ns；
Step 107 obtains an approximation error e, where e is ═ hk-hk-1|；
Step 108, judging whether the approximation error e is larger than or equal to a preset threshold value0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then returning to the step 105, the step 106, the step 107 and the step 108; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Step 109 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure FDA00025118409800000115
Figure FDA00025118409800000116
2. The PLC signal filtering system using a t-profile includes:
the module 201 acquires a signal sequence S acquired in time sequence;
module 202 finds the number of blocks NBLOCKThe formula is obtained as
Figure FDA0002511840980000021
Wherein, SNR is the signal-to-noise ratio of the signal sequence S;
Figure FDA0002511840980000022
is the variance of the signal sequence S;
Figure FDA0002511840980000023
represents lower rounding; n is the length of the signal sequence S;
the module 203 generates the mth block signal sequence smThe formula is obtained as
Figure FDA0002511840980000024
Figure FDA0002511840980000025
Wherein, m is the serial number of the block signal sequence, and the value range is m-1, 2, …, NBLOCK；
Figure FDA00025118409800000217
Is the (m-1) N th of the signal sequence Ss+1 elements;
Figure FDA00025118409800000218
is the (m-1) N th of the signal sequence Ss+2 unitsA peptide;
Figure FDA00025118409800000219
is the mN th of the signal sequence SsAn element; n is a radical ofsFor the mth block signal sequence smIs calculated by the formula
Figure FDA0002511840980000026
Figure FDA0002511840980000027
Representing upper rounding;
the module 204 creates an iteration control parameter k and assigns a value of 0; obtaining an initial value h of the mth t distribution sequence h0The formula is found to be h0＝sm；
The iterative control parameter k of block 205 is incremented by 1 to find the impulse factor αkThe formula is αk＝[1/ln(SNR+1)]k；
The module 206 calculates the kth step h of the mth t distribution sequence hkThe formula is obtained as
Figure FDA0002511840980000028
Figure FDA0002511840980000029
Wherein h isk-1Step k-1 of the mth t distribution sequence h, η is the descending speed, and the calculation formula is
Figure FDA00025118409800000210
pijIs a first adjacent vector, and the calculation formula is
Figure FDA00025118409800000211
qijIs a second adjacent vector, and the calculation formula is
Figure FDA00025118409800000212
Figure FDA00025118409800000213
For the mth block signal sequence smI is the first serial number of the element, and the value range is that i is 1,2, …, Ns；
Figure FDA00025118409800000214
For the mth block signal sequence smJ is the second serial number of the element, and the value range is j equals to 1,2, …, Ns；
The module 207 finds the approximation error e, which is given by the equation e ═ hk-hk-1|；
Module 208 determines whether the approximation error e is greater than or equal to a predetermined threshold0And obtaining a first judgment result. If the first judgment result shows that the approximation error e is greater than or equal to the preset threshold value0Then return to said module 205, said module 206, said module 207, and said module 208; until the first judgment result shows that the approximation error e is smaller than the preset threshold value0(ii) a And obtaining the mth block filtering signal sequence BmThe calculation formula is Bm＝hkWherein the preset threshold ∈0Is composed of0＝0.001；
Module 209 records the noise-filtered signal sequence SNEWIs concretely provided with
Figure FDA00025118409800000215
Figure FDA00025118409800000216
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112362967A (en) * 2020-10-25 2021-02-12 广东石油化工学院 Power signal filtering method and system by utilizing KL divergence

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112362967A (en) * 2020-10-25 2021-02-12 广东石油化工学院 Power signal filtering method and system by utilizing KL divergence

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