CN113765833A - Nonlinear equalization method and device based on multipath decision and storage medium - Google Patents
Nonlinear equalization method and device based on multipath decision and storage medium Download PDFInfo
- Publication number
- CN113765833A CN113765833A CN202110834588.0A CN202110834588A CN113765833A CN 113765833 A CN113765833 A CN 113765833A CN 202110834588 A CN202110834588 A CN 202110834588A CN 113765833 A CN113765833 A CN 113765833A
- Authority
- CN
- China
- Prior art keywords
- signal
- judgment
- decision
- path
- filtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 102
- 238000001914 filtration Methods 0.000 claims abstract description 124
- 238000012545 processing Methods 0.000 claims abstract description 25
- 239000011159 matrix material Substances 0.000 claims description 57
- 230000007480 spreading Effects 0.000 claims description 9
- 238000004364 calculation method Methods 0.000 claims description 4
- 238000004590 computer program Methods 0.000 claims description 3
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 7
- 230000008569 process Effects 0.000 description 20
- 238000004891 communication Methods 0.000 description 16
- 238000013507 mapping Methods 0.000 description 6
- 230000035508 accumulation Effects 0.000 description 5
- 238000009825 accumulation Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000005457 optimization Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 230000003044 adaptive effect Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000004083 survival effect Effects 0.000 description 2
- 208000001992 Autosomal Dominant Optic Atrophy Diseases 0.000 description 1
- 206010011906 Death Diseases 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000007723 transport mechanism Effects 0.000 description 1
Images
Classifications
-
- 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
-
- 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
- H04L25/0202—Channel estimation
- H04L25/0224—Channel estimation using sounding signals
-
- 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
- H04L25/03248—Arrangements for operating in conjunction with other apparatus
- H04L25/03254—Operation with other circuitry for removing intersymbol interference
- H04L25/03267—Operation with other circuitry for removing intersymbol interference with decision feedback equalisers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The application discloses a nonlinear equalization method and device based on multipath judgment and a storage medium. The nonlinear equalization method based on multipath decision comprises the following steps: acquiring a pilot signal; obtaining a filtering parameter according to the pilot signal; acquiring an initial signal; filtering the initial signal according to the filtering parameters to obtain a filtering signal; performing multi-path judgment processing on the filtering signal according to the filtering parameter to obtain a judgment path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the plurality of judgment paths; and obtaining a target signal according to the decision path. The nonlinear equalization method based on multipath judgment can improve the reliability of data transmission.
Description
Technical Field
The present application relates to, but not limited to, the field of communications, and in particular, to a method and an apparatus for nonlinear equalization based on multipath decision, and a storage medium.
Background
The power internet of things system requires that communication among all links has instantaneity and high reliability, the electromagnetic environment and the physical environment of the power system are complex and are easily affected by multipath interference and intersymbol interference, and in order to overcome the above-mentioned influence, a channel equalization technology is often adopted to eliminate the interference, such as a time domain decision feedback nonlinear equalization method based on a space-time filtering structure.
The current nonlinear equalization method adopts a single-path judgment mode, and the accuracy of signal judgment is lower, so that the error rate of a communication system is higher, and the reliability of data transmission is lower.
Disclosure of Invention
The present application is directed to solving at least one of the problems in the prior art. Therefore, the application provides a nonlinear equalization method based on multipath decision, which can solve the problem of low reliability of data transmission.
According to the nonlinear equalization method based on multipath decision in the embodiment of the first aspect of the application, the method comprises the following steps: acquiring a pilot signal; obtaining a filtering parameter according to the pilot signal; acquiring an initial signal; filtering the initial signal according to the filtering parameter to obtain a filtering signal; performing multi-path judgment processing on the filtering signal according to the filtering parameter to obtain a judgment path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the judgment paths; and obtaining a target signal according to the judgment path.
The nonlinear equalization method based on multipath decision according to the embodiment of the application has at least the following technical effects: the nonlinear equalization method based on multipath judgment improves the accuracy of signal judgment, reduces the error rate of a communication system and improves the reliability of data transmission.
According to some embodiments of the present application, the performing a multipath decision process on the filtered signal according to the filtering parameter to obtain a decision path includes: carrying out first path judgment on the filtering signal to obtain a first judgment result; the first judgment result comprises a first judgment path and a first judgment distance; performing second path judgment on the filtered signal to obtain a second judgment result; the second decision result comprises a second decision path and a second decision distance.
According to some embodiments of the present application, the performing a multipath decision process on the filtered signal according to the filtering parameter to obtain a decision path further includes: obtaining the final decision path according to the first decision distance and the second decision distance; and obtaining a target signal according to the final decision path.
According to some embodiments of the present application, the acquiring a pilot signal comprises: acquiring receiving antenna parameters; obtaining a receiving pilot signal time expansion matrix according to the receiving antenna parameters; obtaining a receiving pilot signal matrix according to the receiving pilot signal time spreading matrix; and obtaining the pilot signal according to the received pilot signal matrix.
According to some embodiments of the application, the deriving the filter parameter from the pilot signal comprises: acquiring a pilot signal; obtaining a pilot frequency autocorrelation matrix and a pilot frequency cross-correlation vector according to the pilot frequency signal; and obtaining the filtering parameters according to the pilot frequency autocorrelation matrix and the pilot frequency cross-correlation vector.
According to some embodiments of the application, the acquiring an initial signal comprises: acquiring the receiving antenna parameters; obtaining a receiving initial signal time expansion matrix according to the receiving antenna parameters; obtaining a receiving initial signal matrix according to the receiving initial signal time expansion matrix; and receiving initial signals according to the received initial signal matrix.
According to some embodiments of the present application, the filtering the initial signal according to the filtering parameter to obtain a filtered signal includes: acquiring an initial signal, a delay signal of the initial signal and the filtering parameter; and obtaining the filtering signal according to the delay signal of the initial signal, the initial signal and the filtering parameter.
According to the second aspect of the present application, the apparatus for multipath decision based nonlinear equalization comprises: the pilot frequency acquisition module is used for acquiring a pilot frequency signal; the parameter calculation module is used for obtaining filtering parameters according to the pilot signals; the initial signal acquisition module is used for acquiring an initial signal; the filtering module is used for carrying out filtering processing on the initial signal according to the filtering parameters to obtain a filtering signal; the multipath decision module is used for carrying out multipath decision processing on the filtering signal according to the filtering parameter to obtain a decision path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the judgment paths; and the target signal generation module is used for obtaining a target signal according to the judgment path.
According to the third aspect of the present application, the apparatus for multipath decision based nonlinear equalization comprises: a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor when executing the program implementing: the nonlinear equalization method based on multipath decision in the embodiment of the first aspect of the present application.
A computer-readable storage medium according to an embodiment of the fourth aspect of the present application, having stored thereon computer-executable instructions for: the method for multipath decision based nonlinear equalization according to the embodiment of the first aspect is performed.
Additional aspects and advantages of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the application.
Drawings
The present application is further described with reference to the following figures and examples, in which:
fig. 1 is a flowchart of a multipath decision-based non-linear equalization method according to an embodiment of the present application;
fig. 2 is a flowchart of a multipath decision based non-linear equalization method according to another embodiment of the present application;
fig. 3 is a flowchart of a multipath decision based non-linear equalization method according to another embodiment of the present application;
fig. 4 is a flowchart of a multipath decision based non-linear equalization method according to another embodiment of the present application;
fig. 5 is a flowchart of a multipath decision based non-linear equalization method according to another embodiment of the present application;
fig. 6 is a flowchart of a multipath decision-based non-linear equalization method according to another embodiment of the present application.
Detailed Description
Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.
In the description of the present application, if there are first and second described only for the purpose of distinguishing technical features, it is not understood that relative importance is indicated or implied or that the number of indicated technical features or the precedence of the indicated technical features is implicitly indicated or implied.
In the description of the present application, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The electric power internet of things system requires that information transmission among all links has instantaneity and high reliability, is influenced by functions of the electric power internet of things system, mostly has a non-line-of-sight environment in a signal transmission environment, is serious in multipath interference, and greatly reduces communication quality because signals at a receiving end are influenced by serious intersymbol interference. The channel equalization technology can effectively eliminate intersymbol interference, reduce signal distortion and reduce the error rate.
Meanwhile, due to the openness of a wireless channel and the broadcast characteristic of electromagnetic propagation, a wireless link of the power internet of things is easily interfered by an external electromagnetic environment, so that the problems of network delay and performance reduction are caused.
The existing channel equalization method generally adopts a linear equalization method based on a space-time filtering structure and a time domain decision feedback nonlinear equalization method based on the space-time filtering structure, and specifically comprises the following steps:
(1) the linear equalization method based on the space-time filtering structure carries out weight design in two dimensions of a space domain and a time domain by adding a time domain filter on each receiving antenna, has certain capacities of inhibiting interference and eliminating noise, has low algorithm complexity of linear equalization, and is relatively simple to realize in engineering. The performance of a conventional linear equalization method based on a space-time filtering structure is often inferior to that of a nonlinear equalization method with a decision feedback structure by adding a time-domain filter to each receiving antenna, for example, time-domain decision feedback and frequency-domain iterative equalization often have better interference suppression capability, so that a nonlinear equalization mode is usually adopted in an actual scene.
(2) The time domain decision feedback nonlinear equalization method based on the space-time filtering structure is designed by adopting a single-path decision mode, so that after a certain symbol is misjudged due to the influence of interference, final error propagation of information is easily caused, and the overall performance of a communication system is reduced.
In view of this, the present application provides a nonlinear equalization method based on multi-path decision, which is based on the principle of space-time filtering and utilizes multiple paths to decide a signal, so as to implement nonlinear equalization of the signal, improve demodulation performance of a target signal, and improve reliability of communication. The nonlinear equalization method based on the multipath judgment has the advantages that the nonlinear equalization method based on the multipath judgment has a complex electromagnetic environment and still has strong anti-interference capability in an electric power Internet of things system.
The nonlinear equalization method based on the multipath decision comprises the following steps: acquiring a pilot signal; obtaining a filtering parameter according to the pilot signal; acquiring an initial signal; filtering the initial signal according to the filtering parameters to obtain a filtering signal; performing multi-path judgment processing on the filtering signal according to the filtering parameter to obtain a judgment path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the plurality of judgment paths; and obtaining a target signal according to the decision path.
As shown in fig. 1, fig. 1 is a flowchart of a multipath decision-based nonlinear equalization method provided in some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S110 to S160, and specifically includes:
s110, acquiring a pilot signal;
s120, obtaining a filtering parameter according to the pilot signal;
s130, acquiring an initial signal;
s140, filtering the initial signal according to the filtering parameters to obtain a filtered signal;
s150, performing multi-path judgment processing on the filtering signal according to the filtering parameters to obtain a judgment path;
and S160, obtaining a target signal according to the decision path.
Steps S110 to S120 are a process for calculating a filtering parameter, and receive a pilot signal, and calculate a filtering parameter according to the pilot information, where the filtering parameter includes, but is not limited to, a relevant parameter of space-time filtering.
Steps S130 to S140 are a filtering process of an initial signal, where the initial signal is an expected signal received by a receiving antenna, and the filtered signal is a signal obtained after filtering, where the filtering process includes, but is not limited to, a space-time filtering process, and the filtering process can effectively reduce the influence of a channel on the signal, so as to use the obtained filtered signal for subsequent multipath decision. The space-time filtering process is a filtering process for designing weights in two dimensions of a space domain and a time domain by adding a time domain filter to each receiving antenna.
Steps S150 to S160 are a multipath decision process of the filtered signal, a decision path is obtained after the decision processing, and then a target signal is obtained according to the decision path, where the target signal is a demodulated signal and is also a signal used for characterizing information that needs to be obtained by the receiving end. The multi-path judgment processing is to acquire a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the plurality of judgment paths.
The nonlinear equalization method based on the multipath judgment utilizes the multiple paths to judge the signals, realizes nonlinear equalization of the signals, improves the demodulation performance of target signals, improves the reliability of communication, improves the anti-interference capability of the signals in complex electromagnetic environments such as an electric power internet of things system and the like, improves the accuracy of signal judgment, reduces the error rate of the communication system, and improves the reliability of data transmission.
According to some embodiments of the present application, performing a multipath decision process on a filtered signal according to a filtering parameter to obtain a decision path, includes: carrying out first path judgment on the filtering signal to obtain a first judgment result; the first judgment result comprises a first judgment path and a first judgment distance; performing second path judgment on the filtered signal to obtain a second judgment result; the second decision result comprises a second decision path and a second decision distance.
According to some embodiments of the present application, the multipath decision processing is performed on the filtered signal according to the filtering parameter to obtain a decision path, and the method further includes: obtaining a final judgment path according to the first judgment distance and the second judgment distance; and obtaining a target signal according to the final judgment path.
As shown in fig. 2, fig. 2 is a flowchart of a multipath decision-based nonlinear equalization method provided in some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S110 to S140, and specifically includes:
s210, performing first path judgment on the filtering signal to obtain a first judgment result;
s220, performing second path judgment on the filtering signal to obtain a second judgment result;
s230, obtaining a final judgment path according to the first judgment distance and the second judgment distance;
and S240, obtaining a target signal according to the final judgment path.
In steps S210 to S220, the first decision result includes a first decision path and a first decision distance; the second decision result comprises a second decision path and a second decision distance.
In some embodiments, the initial signal is also referred to as a target desired signal, and the initial signal is expressed as
Wherein N isdIs the desired signal length. Defining an i-th time delay of the initial signal as
Wherein, b (N)b-i+1) … b(Nb) For i symbols, N, after the known pilot signalbFor a known pilot signal length, I ∈ {1, 2.., I } where I is the maximum time delay; the initial signal d satisfies the following relation:
wherein the delay coefficient alphaiObtained by step S120, the space-time filtered signal d' is obtained by step S140,
first, the 1 st symbol of the original signal d is obtained:
performing multi-path judgment on the first symbol d (1) of the obtained target expected signal, reserving two constellation points closest to d (1) as useful constellation points, and judging d (1) as dA(1) And dB(1) D (1) from dA(1) And dB(1) Respectively, are denoted as D2(1) And L2(1)。
In the first path judgment process, judging d (1) as dA(1) After d by decisionA(1) In place of the initial signal d1 symbol, 2 nd symbol of the initial signal d:
recording the distance D of D (2) from each constellation point2(2) And with D2(1) Accumulating to obtain a first decision distance, i.e. the accumulated distance value S of the first decision path1＝D2(1)+D2(2) If a total of Q constellation points are assumed, there are Q different accumulated distance values.
It should be noted that, because the modulation modes used in the communication are different, each modulation mode corresponds to a respective constellation diagram, and therefore the number of constellation points is also different, in the first path decision process, if there are Q constellation points, Q path branches are corresponding, that is, the obtained first decision result includes Q first decision paths and Q first decision distances.
In the second path decision process, d (1) is decided as dB(1) After d by decisionB(1) Instead of the 1 st symbol of the original signal d, the 2 nd symbol of the original signal d, similarly:
record the distance L of d (2) from each constellation point2(2) And is combined with L2(1) Accumulating to obtain a second decision distance, i.e. a distance accumulated value S of a second decision path2＝L2(1)+L2(2) If a total of Q constellation points are assumed, there are Q different accumulated distance values.
It should be noted that, in the second path decision process, if there are Q constellation points, Q path branches are corresponded, that is, the obtained second decision result includes Q second decision paths and Q second decision distances.
In step S230, two of the 2Q decision distances with the smallest value are selected to obtain two decision paths corresponding to the two decision distances as the final decision path, and d (1) and d (2) decided in the final decision path are used according to the two decision paths
To obtain d (3), andd (3) performing multipath judgment the same as d (2), namely taking two judgment paths obtained by the multipath judgment for the first time as two initial paths of d (2), performing first path judgment and second path judgment on the basis, obtaining 2Q judgment distances and 2Q judgment paths corresponding to the judgment distances in the judgment process from d (2) to d (3), selecting two paths with the minimum value from the judgment distances, and continuously judging the symbols of the subsequent initial signals until all judged symbols in the target expected signal d are obtained.
It should be noted that, when the symbol of the last initial signal is decided, the decision path with the smallest accumulated distance value is selected as the final decision path, and the feedback equalization is completed.
In step S240, a target signal is obtained according to the obtained final decision path and the rule corresponding to the constellation diagram, and the data demodulation process is completed.
According to some embodiments of the present application, acquiring a pilot signal comprises: acquiring receiving antenna parameters; obtaining a receiving pilot signal time expansion matrix according to the receiving antenna parameters; obtaining a receiving pilot signal matrix according to the receiving pilot signal time spreading matrix; and obtaining a pilot signal according to the received pilot signal matrix.
As shown in fig. 3, fig. 3 is a flowchart of a multipath decision-based nonlinear equalization method according to some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S310 to S340, and specifically includes:
s310, acquiring receiving antenna parameters;
s320, obtaining a receiving pilot signal time expansion matrix according to the receiving antenna parameters;
s330, obtaining a receiving pilot signal matrix according to the receiving pilot signal time spreading matrix;
and S340, obtaining a pilot signal according to the received pilot signal matrix.
In a specific embodiment, the principle of the process of calculating the space-time filtering parameters according to the pilot signals is to solve an optimization problem:
wherein, arg is parameter solving function, Y is receiving pilot signal matrix, W is space-time filtering self-adapting weight, b' is pilot signal containing partial residual time delay component, alphaiThe delay coefficient corresponding to the ith time delay of the known pilot signal. The space-time filtering parameters include, but are not limited to, the adaptive weight W of the space-time filtering, and the delay coefficient α corresponding to the ith time delay of the pilot signali。
In the above-described embodiment of the present invention,
for the known pilot signal, NbFor the known pilot signal length, biFor the ith time delay of the known pilot signal, αibiThe corresponding delay factor, I, is the maximum value of the time delay.
In step S310, the receiving antenna parameters include, but are not limited to, the number M of receiving antennas, the number K of time-domain taps of each receiving antenna filter, and the length N of the pilot signalb。
In step S320, the k-bit delayed pilot signal on the mth receiving antenna is recorded as
K belongs to {0, 1, …, K-1}, and the time spreading matrix of the received pilot signal on the mth receiving antenna can be obtained as
M ∈ {1, 2., M }, where N isbThe known pilot signal length.
In steps S330 to S340, a received pilot signal matrix is obtained according to the received pilot signal time spreading matrix
The receive pilot signal matrix is used to receive pilot signals.
According to some embodiments of the application, deriving the filter parameter from the pilot signal comprises: acquiring a pilot signal; obtaining a pilot autocorrelation matrix and a pilot cross-correlation vector according to the pilot signal; and obtaining filtering parameters according to the pilot frequency autocorrelation matrix and the pilot frequency cross-correlation vector.
As shown in fig. 4, fig. 4 is a flowchart of a multipath decision-based nonlinear equalization method provided in some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S410 to S430, and specifically includes:
s410, acquiring a pilot signal;
s420, obtaining a pilot autocorrelation matrix and a pilot cross-correlation vector according to the pilot signal;
and S430, obtaining filtering parameters according to the pilot autocorrelation matrix and the pilot cross-correlation vector.
In steps S410 to S420, the pilot autocorrelation matrix R ═ Y')HY ', pilot cross-correlation vector p ═ Y')Hb，
The matrix is combined for the pilot signals.
In step S430, the adaptive weight of the space-time filter is
Wherein the content of the first and second substances,
m belongs to {1, 2,. and M } is a self-adaptive weight corresponding to the mth receiving antenna; in the parameter solving process, the solution for solving the parameter optimization problem is as follows: w ═ R-1p, obtaining the space-time filtering related parameter as
The solution of the space-time filtering parameters is completed.
According to some embodiments of the present application, acquiring an initial signal comprises: acquiring receiving antenna parameters; obtaining a time expansion matrix of the received initial signal according to the parameters of the receiving antenna; obtaining a receiving initial signal matrix according to the receiving initial signal time expansion matrix; an initial signal is received according to a received initial signal matrix.
As shown in fig. 5, fig. 5 is a flowchart of a multipath decision-based nonlinear equalization method according to some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S510 to S540, and specifically includes:
s510, obtaining receiving antenna parameters;
s520, obtaining a time expansion matrix of the received initial signal according to the parameters of the receiving antenna;
s530, obtaining a receiving initial signal matrix according to the receiving initial signal time expansion matrix;
and S540, receiving the initial signal according to the initial signal receiving matrix.
In step S510, the receiving antenna parameters further include an initial signal length NdAlso known as the desired signal length.
In step S520, the k-bit delayed initial signal is received on the mth receiving antenna
Wherein K belongs to {0, 1.,. K-1}, and further obtains a time expansion matrix of the received initial signal on the mth receiving antenna
Where M is in {1, 2,. multidot.M },
in steps S530 to S540, a received initial signal matrix is obtained according to the received initial signal time spreading matrix on the m-th receiving antenna
And then receiving the signal according to the initial signal receiving matrix.
According to some embodiments of the present application, the filtering the initial signal according to the filtering parameter to obtain a filtered signal includes: acquiring an initial signal, a delay signal of the initial signal and a filtering parameter; and obtaining a filtering signal according to the delay signal, the initial signal and the filtering parameter of the initial signal.
As shown in fig. 6, fig. 6 is a flowchart of a multipath decision-based nonlinear equalization method provided in some embodiments, where the multipath decision-based nonlinear equalization method includes, but is not limited to, steps S610 to S630, and specifically includes:
s610, acquiring an initial signal, a delay signal of the initial signal and a filtering parameter;
and S620, obtaining a filtering signal according to the delay signal of the initial signal, the initial signal and the filtering parameter.
In steps S610 to S620, the filtered signal obtained after the space-time filtering process is denoted as d',
wherein the content of the first and second substances,
for the target desired signal, diIs the ith time delay of the target desired signal, I is the maximum time delay, the space-time filtering self-adaptive weight W and the delay coefficient alphaiAre filter parameters.
The following describes the multipath decision based non-linear equalization method in detail in a specific embodiment. It is to be understood that the following description is illustrative only and is not intended to be in any way limiting.
In the existing design of the space-time filtering scheme, signals after timing synchronization are equalized through space-time filtering, all multipath interference is hopefully eliminated at one time, and the signals after space-time equalization are directly subjected to symbol judgment. The advantages of this are convenient processing and simple hardware implementation, but such processing is too aggressive and often difficult to obtain optimal performance. Based on the method, a nonlinear equalization method based on multipath judgment is provided for the power internet of things, a part of multipath interference is eliminated in a space-time filtering part, and the remaining interference is further eliminated in a subsequent judgment feedback part. All multipath interference of the signal after space-time filtering and equalization is eliminated, and symbol judgment can be directly carried out. The way of dividing the space-time filtering and the judgment into two steps can improve the performance of the system to a certain extent.
In a particular embodiment, the receiving is performed without interferenceThe end uses 4 omnidirectional antennas to receive signals, non-line-Of-sight channel modeling is adopted, the equivalent channel length is 10 baseband symbols, the time domain tap number K Of each receiving antenna filter is 20, the DOA (Direction Of Arrival) number Of each path is 100, the angle spread Of incoming wave signals is 360 degrees, the tap number Of feedback filters is 7, and the pilot signal length N is Nb352, desired signal length Nd1280, simulation experiments are carried out by adopting two constellation mapping modes of QPSK and 16 QAM.
In the original space-time filter equalization scheme, the core of weight design is to minimize the difference between the pilot part after space-time equalization and the known pilot b. The weight value designed in this way can make the data part after space-time equalization consistent with the ideal data as much as possible. In the method of the present invention, in order to prevent the space-time filtering from eliminating all multipath interference and external interference, the pilot frequency part after space-time equalization is equal to the pilot frequency containing part of residual delay components.
Firstly, calculating a space-time filtering related parameter through a pilot signal received by a receiving end, and solving the following optimization problem:
wherein the content of the first and second substances,
for pilots that contain a portion of the residual delay component,
for the known pilot signal, biFor the ith time delay, alpha, of the known pilot signaliIs b isiCorresponding delay coefficient, I-7 is the maximum time delay value, i.e. the number of taps of the feedback filter;
in order to receive the matrix of pilot signals,
m∈{1，2，...，Mis the received pilot signal time spreading matrix on the mth receive antenna,
k belongs to {0, 1.,. K-1} and is a received pilot signal with a delay of K bits on the mth receiving antenna;
the weights are adapted for the space-time filtering,
and M belongs to {1, 2.,. M } and is the self-adaptive weight corresponding to the mth receiving antenna.
The solution to the above optimization problem is: w ═ R-1p, where the autocorrelation matrix R ═ Y')HY ', cross-correlation vector p ═ Y')Hb，
The matrix is combined for the pilot signals, thus completing the solution of the space-time filtering parameters.
Then, the initial signal is subjected to space-time filtering according to the space-time filtering related parameters. Defining a matrix of received desired signals
Wherein the content of the first and second substances,
m ∈ {1, 2.,. M } is a time spreading matrix of a received desired signal on the mth receiving antenna,
k belongs to {0, 1.,. K-1} and is a received expected signal with a delay of K bits on the mth receiving antenna; after receiving the expected signal and performing space-time filtering, the following results are obtained:
wherein d' is a space-time filtering post-expectation signal,
for the target desired signal, diThe ith time delay of the target desired signal.
And finally, carrying out multipath decision feedback equalization on the space-time filtered expected signal. Defining a target desired signal as
Wherein N isd1280 is the expected signal length; defining an ith time delay of the target desired signal as
Wherein, b (N)b-i+1) … b(Nb) For i symbols, N, after the known pilot signalb352 is the known pilot signal length, I ∈ {1, 2., I }, and I ═ 7 is the maximum time delay value, i.e., the number of taps of the feedback filter; the initial signal d satisfies the following relation:
wherein the content of the first and second substances,
it should be noted that, since the interference of the last 1 to I symbols in the pilot signal to the 1 st symbol of the target desired signal d remains, this interference needs to be subtracted before the decision, and the calculation method for subtracting the interference is as follows
In a specific embodiment, constellation mapping is QPSK mapping, multipath decision is performed on the first symbol d (1) of the obtained target desired signal, two constellation points closest to d (1) are reserved as useful constellation points, and d (1) is decided as dA(1) And dB(1) D (1) from dA(1) And dB(1) Respectively, are denoted as D2(1) And L2(1). After the 1 st symbol of the initial signal d is decided, the decided result is retained, and the result is usedThe result of the secondary decision is used for deciding the next symbol, and the decision is respectively considered as dA(1) And dB(1) Two different decision cases.
A first decision path for deciding d (1) as dA(1) After d by decisionA(1) After subtracting the interference caused by other symbols instead of the 1 st symbol of the original signal d, the 2 nd symbol of the original signal d is:
respectively recording the distances D of D (2) from four constellation points2(2) And with D2(1) Accumulation, distance accumulation value S of first decision path1＝D2(1)+D2(2) Note D2(2) There are 4 different results, so there are 4 different distance accumulations in this case.
A second decision path for deciding d (1) as dB(1) After d by decisionB(1) After subtracting the interference caused by other symbols instead of the 1 st symbol of the original signal d, the 2 nd symbol of the original signal d:
respectively recording the distances L of d (2) from four constellation points2(2) And is combined with L2(1) Accumulation, distance accumulation value S of the second path2＝L2(1)+L2(2)，L2(2) There are 4 different results, so there are 4 different accumulated distance values under this situation, in these 8 accumulated distance values, choose the minimum two, get two new decision paths, utilize d (1) and d (2) after the decision in these two decision paths, get d (3) according to the relational expression, and carry on the multipath decision the same as d (2) to d (3), until obtaining all symbol after decision in the target desired signal d, choose the minimum one of accumulated distance value as the final decision path at this moment, finish feedback equalization.
Under the condition of no external interference, the nonlinear equalization method based on the multipath decision provided by the application is mistakenly applied to two different constellation mapping modes, namely QPSK and 16QAMThe bit rate is compared with other equalization methods, and other methods comprise an original space-time filtering linear equalization method, a single-path decision feedback method and a frequency domain iterative equalization method. Under two constellation mapping modes, the nonlinear equalization method based on multipath decision can achieve the best performance, and the QPSK modulation is performed at 10 DEG-4The performance of the bit error rate can be improved by 1.3dB compared with the original space-time equalization, and the 16QAM is improved by nearly 2 dB.
When external interference exists, on the basis of the simulation condition that the external interference does not exist, non-line-of-sight interference is additionally added, an interference signal also passes through a non-line-of-sight channel, the length of the channel is also set to be 10 baseband symbol rates, the number of DOAs is 100, the incoming wave center angle of an expected signal is 0 degree, the incoming wave center angle of the interference signal is 90 degrees, and the signal-to-interference ratio is set to be 0 dB. The nonlinear equalization method based on multipath decision can obtain performance improvement larger than that of the original equalization scheme. Wherein, the single path decision feedback based on the space-time filtering structure is close to the frequency domain iterative equalization performance, and the signal path decision feedback based on the space-time filtering structure is 10 times in QPSK modulation-4The bit error rate can be improved by 1.3dB compared with the original space-time equalization, and the bit error rate is 10 ℃ during 16QAM modulation-3The bit error rate is improved by nearly 2dB compared with the original space-time equalization. The nonlinear equalization method based on the multi-path judgment can respectively obtain 2.5dB and 3dB performance improvement under QPSK and 16QAM constellation mapping modes. In conclusion, under the condition that extra non-line-of-sight interference exists, the nonlinear equalization method based on multipath judgment provided by the application shows better anti-interference performance than various traditional methods, and effectively improves the survival capability of a communication link in a complex electromagnetic environment.
The nonlinear equalization method based on multipath decision comprises a nonlinear decision feedback part, and compared with the traditional linear space-time filtering scheme, the nonlinear equalization method based on multipath decision has the advantages of higher performance; compared with the traditional single-path judgment, the multi-path judgment-based nonlinear equalization method can correct the misjudgment result according to the accumulated value of the paths during subsequent path selection after a certain signal is misjudged due to the influence of interference in the middle in the multi-path judgment mode, thereby well reducing the error propagation probability; in addition, under the condition that extra non-line-of-sight interference exists, the multi-path-decision-based nonlinear equalization method is superior to a traditional single-path decision equalization method and a traditional frequency domain iterative equalization method which adopt a space-time filtering structure, good anti-interference capacity is shown, safe and reliable signal transmission can be achieved in a complex electromagnetic interference environment, and the survival capacity of the power internet-of-things communication link in the complex electromagnetic interference environment is effectively improved.
According to the nonlinear equalization device based on multipath decision of the embodiment of the application, the nonlinear equalization device based on multipath decision comprises: the pilot frequency acquisition module is used for acquiring a pilot frequency signal; the parameter calculation module is used for obtaining filtering parameters according to the pilot signals; the initial signal acquisition module is used for acquiring an initial signal; the filtering module is used for filtering the initial signal according to the filtering parameters to obtain a filtering signal; the multipath decision module is used for carrying out multipath decision processing on the filtering signal according to the filtering parameter to obtain a decision path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the plurality of judgment paths; and the target signal generation module is used for obtaining a target signal according to the judgment path.
The nonlinear equalization device based on the multipath judgment realizes a nonlinear equalization method based on the multipath judgment, judges signals by utilizing a plurality of paths, realizes nonlinear equalization of the signals, improves the demodulation performance of target signals, improves the reliability of communication, improves the anti-interference capability of the signals in complex electromagnetic environments such as an electric power internet of things system and the like, improves the accuracy of signal judgment, reduces the error rate of a communication system, and improves the reliability of data transmission.
According to the nonlinear equalization device based on multipath decision of the embodiment of the application, the nonlinear equalization device based on multipath decision comprises: a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor when executing the program implementing: the nonlinear equalization method based on multipath decision according to any of the above embodiments of the present application.
A computer-readable storage medium according to an embodiment of the present application stores computer-executable instructions for: the multipath decision based non-linear equalization method of any of the above embodiments is performed.
The above-described embodiments of the apparatus are merely illustrative, wherein the units illustrated as separate components may or may not be physically separate, i.e. may be located in one place, or may also be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.
It will be understood by those of ordinary skill in the art that all or some of the steps, means, and methods disclosed above may be implemented as software, firmware, hardware, or suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
The embodiments of the present application have been described in detail with reference to the drawings, but the present application is not limited to the embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present application. Furthermore, the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
Claims (10)
1. A nonlinear equalization method based on multipath decision is characterized by comprising the following steps:
acquiring a pilot signal;
obtaining a filtering parameter according to the pilot signal;
acquiring an initial signal;
filtering the initial signal according to the filtering parameter to obtain a filtering signal;
performing multi-path judgment processing on the filtering signal according to the filtering parameter to obtain a judgment path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the judgment paths;
and obtaining a target signal according to the judgment path.
2. The method for multipath decision based nonlinear equalization according to claim 1, wherein the multipath decision processing of the filtered signal according to the filter parameter to obtain a decision path comprises:
carrying out first path judgment on the filtering signal to obtain a first judgment result; the first judgment result comprises a first judgment path and a first judgment distance;
performing second path judgment on the filtered signal to obtain a second judgment result; the second decision result comprises a second decision path and a second decision distance.
3. The method for multipath decision based nonlinear equalization according to claim 2, wherein the multipath decision processing is performed on the filtered signal according to the filter parameter to obtain a decision path, further comprising:
obtaining the final decision path according to the first decision distance and the second decision distance;
and obtaining a target signal according to the final decision path.
4. The multi-path decision based nonlinear equalization method as claimed in claim 1, wherein the acquiring the pilot signal comprises:
acquiring receiving antenna parameters;
obtaining a receiving pilot signal time expansion matrix according to the receiving antenna parameters;
obtaining a receiving pilot signal matrix according to the receiving pilot signal time spreading matrix;
and obtaining the pilot signal according to the received pilot signal matrix.
5. The method of multipath decision based nonlinear equalization according to claim 4, wherein the deriving filter parameters from the pilot signal comprises:
acquiring a pilot signal;
obtaining a pilot frequency autocorrelation matrix and a pilot frequency cross-correlation vector according to the pilot frequency signal;
and obtaining the filtering parameters according to the pilot frequency autocorrelation matrix and the pilot frequency cross-correlation vector.
6. The method of multipath decision based nonlinear equalization according to claim 1, wherein the acquiring an initial signal comprises:
acquiring the receiving antenna parameters;
obtaining a receiving initial signal time expansion matrix according to the receiving antenna parameters;
obtaining a receiving initial signal matrix according to the receiving initial signal time expansion matrix;
and receiving initial signals according to the received initial signal matrix.
7. The method for multipath decision based nonlinear equalization according to claim 6, wherein the filtering the initial signal according to the filter parameter to obtain a filtered signal comprises:
acquiring an initial signal, a delay signal of the initial signal and the filtering parameter;
and obtaining the filtering signal according to the delay signal of the initial signal, the initial signal and the filtering parameter.
8. A nonlinear equalization apparatus based on multipath decision, comprising:
the pilot frequency acquisition module is used for acquiring a pilot frequency signal;
the parameter calculation module is used for obtaining filtering parameters according to the pilot signals;
the initial signal acquisition module is used for acquiring an initial signal;
the filtering module is used for carrying out filtering processing on the initial signal according to the filtering parameters to obtain a filtering signal;
the multipath decision module is used for carrying out multipath decision processing on the filtering signal according to the filtering parameter to obtain a decision path; the multi-path judgment processing is to obtain a plurality of judgment paths and obtain a final judgment path according to judgment distances corresponding to the judgment paths;
and the target signal generation module is used for obtaining a target signal according to the judgment path.
9. A multipath decision based nonlinear equalization apparatus, wherein the multipath decision based nonlinear equalization method apparatus comprises: a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor when executing the program implementing:
a multi-path decision based non-linear equalization method as claimed in any one of claims 1 to 7.
10. A storage medium having stored thereon computer-executable instructions for:
performing the multipath decision based non-linear equalization method of any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110834588.0A CN113765833B (en) | 2021-07-23 | 2021-07-23 | Nonlinear equalization method, device and storage medium based on multipath decision |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110834588.0A CN113765833B (en) | 2021-07-23 | 2021-07-23 | Nonlinear equalization method, device and storage medium based on multipath decision |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113765833A true CN113765833A (en) | 2021-12-07 |
| CN113765833B CN113765833B (en) | 2023-12-29 |
Family
ID=78787862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110834588.0A Active CN113765833B (en) | 2021-07-23 | 2021-07-23 | Nonlinear equalization method, device and storage medium based on multipath decision |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113765833B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1627739A (en) * | 2003-12-10 | 2005-06-15 | 日本电气株式会社 | Equalizer and method of setting initial value for same |
| CN102882817A (en) * | 2012-09-26 | 2013-01-16 | 华为技术有限公司 | Equalizer circuit, data transmission system and equalization method |
| CN110061761A (en) * | 2018-01-19 | 2019-07-26 | 华为技术有限公司 | Signal equalizing method and device, photoreceiver |
-
2021
- 2021-07-23 CN CN202110834588.0A patent/CN113765833B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1627739A (en) * | 2003-12-10 | 2005-06-15 | 日本电气株式会社 | Equalizer and method of setting initial value for same |
| CN102882817A (en) * | 2012-09-26 | 2013-01-16 | 华为技术有限公司 | Equalizer circuit, data transmission system and equalization method |
| CN110061761A (en) * | 2018-01-19 | 2019-07-26 | 华为技术有限公司 | Signal equalizing method and device, photoreceiver |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113765833B (en) | 2023-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1119953B1 (en) | Channel estimator with variable number of taps | |
| US7564912B2 (en) | Method and apparatus for channel state information generation in a DVB-T receiver | |
| US6912249B2 (en) | Method and system for training a radio receiver | |
| EP1422850A1 (en) | Multi-pass interference removal apparatus and multi-pass interference removal method | |
| US5455844A (en) | Selection diversity system using decision feedback equalizer in digital mobile telecommunication systems | |
| US6898239B2 (en) | Method of detecting a sequence of information symbols, and a mobile station adapted to performing the method | |
| US20060200511A1 (en) | Channel equalizer and method of equalizing a channel | |
| US20110268169A1 (en) | Equalization apparatus and broadcasting receiving apparatus | |
| JPH06197032A (en) | Adaptive equalizer | |
| EP1349338A2 (en) | Compensation of phase and frequency errors in a multicarrier receiver | |
| KR101106684B1 (en) | Apparatus and method for receiver in multiple antenna system | |
| US10924248B2 (en) | Signal-to-noise ratio determining method and device, and channel equalization method and device | |
| US7173991B2 (en) | Methods and apparatus for spectral filtering channel estimates | |
| US8180005B2 (en) | Apparatus and method for selecting optimal signal using auxiliary equalization in diversity receiver | |
| US7143013B2 (en) | Reliable symbols as a means of improving the performance of information transmission systems | |
| JP2001251226A (en) | Two-way viterbi equalizer | |
| JP2007158721A (en) | Receiver, and symbol section extraction method | |
| CN113765833B (en) | Nonlinear equalization method, device and storage medium based on multipath decision | |
| US20020167999A1 (en) | Equalizer, receiver, and equalization method and reception method | |
| CN113037658B (en) | Signal detection method, signal detection device, communication equipment and computer storage medium | |
| WO2013171823A1 (en) | Receiving device and receiving method | |
| EP4094411A1 (en) | Receiver devices and methods for multicarrier modulation schemes | |
| JP2000068910A (en) | Diversity reception device | |
| US20120243628A1 (en) | Reception device, reception method, and reception program | |
| CN114938321B (en) | Method for channel estimation by using data symbol as reference signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 518000, 3rd Floor, Building 40, Baotian Industrial Zone, Chentian Community, Xixiang Street, Bao'an District, Shenzhen City, Guangdong Province Applicant after: China Southern Power Grid Digital Platform Technology (Guangdong) Co.,Ltd. Address before: 510000 501, 502, 601 and 602, building D, wisdom Plaza, Qiaoxiang Road, Gaofa community, Shahe street, Nanshan District, Shenzhen, Guangdong Applicant before: China Southern Power Grid Shenzhen Digital Power Grid Research Institute Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |