CN112968852A - Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment - Google Patents

Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment Download PDF

Info

Publication number
CN112968852A
CN112968852A CN202011544946.6A CN202011544946A CN112968852A CN 112968852 A CN112968852 A CN 112968852A CN 202011544946 A CN202011544946 A CN 202011544946A CN 112968852 A CN112968852 A CN 112968852A
Authority
CN
China
Prior art keywords
signal
bfdm
otfs
amplitude limiting
matrix
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.)
Pending
Application number
CN202011544946.6A
Other languages
Chinese (zh)
Inventor
王亮
冯宇
祝涛
别志松
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang Shannon Communication Technology Co ltd
Original Assignee
Zhejiang Shannon Communication Technology Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhejiang Shannon Communication Technology Co ltd filed Critical Zhejiang Shannon Communication Technology Co ltd
Priority to CN202011544946.6A priority Critical patent/CN112968852A/en
Publication of CN112968852A publication Critical patent/CN112968852A/en
Priority to CN202111046326.4A priority patent/CN113489666B/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2614—Peak power aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/264—Pulse-shaped multi-carrier, i.e. not using rectangular window
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2668—Details of algorithms
    • H04L27/2681—Details of algorithms characterised by constraints
    • H04L27/2688—Resistance to perturbation, e.g. noise, interference or fading

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Noise Elimination (AREA)

Abstract

The invention provides a method and a system for eliminating amplitude limiting noise based on peak-to-average ratio inhibition and electronic equipment. According to the method, the peak-to-average ratio of the OTFS-BFDM signal is suppressed by using an amplitude limiting and filtering method at a sending end, amplitude limiting noise is reconstructed by using the same modulation and amplitude limiting method as that at the sending end, and the residual quantity of the amplitude limiting noise in an initial receiving signal is reduced by means of iterative elimination, so that the accuracy of system decoding is improved while the peak-to-average ratio of the OTFS-BFDM signal is reduced.

Description

Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment
[ technical field ] A method for producing a semiconductor device
The present application relates to the field of wireless communication technologies, and in particular, to a method, a system, and an electronic device for eliminating clipping noise based on peak-to-average power ratio suppression.
[ background of the invention ]
Next generation wireless systems (5G and beyond) are intended to facilitate seamless and reliable communications in high mobility environments, including high speed train, airplane, vehicle-to-vehicle, and vehicle-to-infrastructure communications. While Orthogonal Frequency Division Multiplexing (OFDM) systems can achieve high spectral efficiency over time-invariant, frequency-selective channels, they exhibit insufficient robustness over time-variant channels with high doppler spread. Recently proposed Orthogonal Time Frequency Space (OTFS) systems have proven to have significant advantages over OFDM in high mobility environments. And further, OTFS transformation and dual-orthogonal frequency division multiplexing (BFDM) modulation are combined to form an OTFS-BFDM system, the system has a longer non-rectangular prototype window function, flexible waveform design and lower out-of-band dispersion can be realized, and the sparse connectivity of the system is ensured. However, the peak-to-average ratio (PAPR) of the OTFS-BFDM signal becomes higher as the number of symbols in the transmission interval increases. When the PAPR is too high, the transmitter may cause nonlinear distortion of the signal, ultimately affecting the BER performance of the system. Therefore, it is urgent to take effective measures to suppress the PAPR of the OTFS-BFDM system.
In a multi-carrier system based on a Message Passing (MP) signal detection algorithm, in order to not destroy the sparse connectivity of the system, a selective mapping method and an MP auxiliary amplitude limiting method are mostly adopted to inhibit the PAPR of a signal at present, the former causes signal distortion, but requires sideband information transmission and reduces the spectrum utilization rate, and the latter takes amplitude limiting noise and channel noise as the noise input of the MP algorithm, so that the amplitude limiting interference is relieved, but the influence on the system BER is still large.
In view of this, the present invention provides a method for eliminating clipping noise for peak-to-average power ratio suppression in an OTFS-BFDM system, which can recover the BER performance of the system as much as possible while solving the problem of too high PAPR of the system.
[ summary of the invention ]
The invention provides a method, a system and electronic equipment for eliminating amplitude limiting noise based on peak-to-average ratio suppression, wherein the following technical scheme is adopted, under the assumption that a channel state, an amplitude limiting parameter and a window function are completely known at a receiving end, and a modulation symbol (such as 4QAM) of an OTFS-BFDM system is transmitted on a delay Doppler grid, wherein the sum respectively represents the maximum Doppler and delay offset:
a clipping noise elimination method based on peak-to-average ratio suppression is applied to a clipping noise elimination system and comprises the following steps:
step 1, at a sending end, carrying out primary amplitude limiting and filtering on an OTFS-BFDM modulation signal to obtain an amplitude limiting processing signal s';
and step 2, at the receiving end,after the initial receiving signal r is subjected to attenuation removing processing, an observation signal vector on a time domain is obtained through BFDM demodulation and octant-limited Fourier transform (SFFT)
Figure RE-GDA0003053199250000021
Will be provided with
Figure RE-GDA0003053199250000022
Substituting MP algorithm for channel equalization and decoding judgment, and outputting variable signal vector
Figure RE-GDA0003053199250000023
Step 3, outputting the judgment output variable signal vector
Figure RE-GDA0003053199250000024
The OTFS-BFDM is modulated and then divided into two paths, one path is subjected to amplitude limiting and filtering processing which are the same as those of a sending end, so that a first path of amplitude limiting processing signal is obtained
Figure RE-GDA0003053199250000025
The other path is multiplied by a limiting attenuation factor to obtain a second path of attenuation processing signals
Figure RE-GDA0003053199250000026
Limiting the first path of amplitude-limiting processing signal
Figure RE-GDA0003053199250000027
And the second path of attenuation processing signal
Figure RE-GDA0003053199250000028
Subtracting to obtain a reconstructed amplitude limiting noise vector delta ', and obtaining a reconstructed amplitude limiting noise estimation H delta ' at the receiver end after the amplitude limiting noise vector delta ' passes through a channel convolution matrix;
step 4, subtracting the reconstructed clipping noise H delta' from the original received signal r to obtain a modified received signal r1The next iteration is performed on the modified received signal r ═ Hs '+ w-H δ ═ H' + w-H δ1Performing attenuation removal processing and OTFS-BFDM demodulation to obtain a corrected observation signal vector
Figure RE-GDA0003053199250000029
Step 5, the corrected received signal r1Replacing the initial received signal r, returning to the step 2 and repeatedly executing the step 2, and according to a preset maximum iteration time taumaxWhen the number of iterations reaches τmaxAnd then jumping out and finishing the amplitude limiting noise elimination.
Further, the performing of primary amplitude limiting and filtering on the OTFS-BFDM modulated signal specifically includes:
the relation between the OTFS-BFDM modulation signal and the amplitude limiting processing signal s 'is expressed as s' ═ α s + δ, wherein s is the OTFS-BFDM modulation signal, α represents the amplitude limiting attenuation factor, and δ is the amplitude limiting noise vector;
the clipping attenuation factor α is calculated by the following formula:
Figure RE-GDA0003053199250000031
the signal of the sending end after amplitude limiting processing is
Figure RE-GDA0003053199250000032
Wherein d represents a modulation symbol vector;
p is a block circulant matrix and,
Figure RE-GDA0003053199250000033
Λ is a diagonal matrix, Λ ═ diag (Λ)0,Λ1,…,ΛN-1) And is obtained by the following formula:
Figure RE-GDA0003053199250000034
for each sub-matrix in Λ, the matrix Φ (i, j) is not empty only if the i ═ j element is not equal to 0.
Further, the OTFS-BFDM modulation signal is calculated by a transmission matrix of an OTFS-BFDM system, wherein the transmission matrix of the OTFS-BFDM system is
Figure RE-GDA0003053199250000035
Wherein
Figure RE-GDA0003053199250000036
Is the ISSFT transform and is,
Figure RE-GDA0003053199250000037
and IMRespectively representing a normalized N-point IDFT matrix and an M-dimensional identity matrix,
Figure RE-GDA0003053199250000038
representing the kronecker product, P is the filter coefficient matrix of the BFDM analysis, and P is represented by
Figure RE-GDA0003053199250000039
Where p (N) is an analysis filter prototype window function of length L ═ MN, 0 ≦ i ≦ N-1.
Further, the PAPR of the clipping noise cancellation system is preset, and the PAPR of the discrete time sample of a frame of OTFS-BFDM transmission signal is defined as:
Figure RE-GDA0003053199250000041
wherein s (l) is an output signal of the OTFS-BFDM transmitter in the time domain, and l is more than or equal to 0 and less than or equal to MN;
the PAPR performance of the clipping noise cancellation system is measured by a complementary cumulative distribution function CCDF that calculates that the peak power ratio of each transmitted sample value exceeds a predefined threshold (PAPR)0) The complementary cumulative distribution function CCDF has statistical properties, and is calculated by the following formula:
CPAPR(PAPR0)＝Pr(PAPR＞PAPR0)＝1-Pr(PAPR≤PAPR0)＝1-(1-exp(-PAPR0))L。
further, the performing attenuation-removing processing on the initial received signal r specifically includes:
after the amplitude limiting processing signal s 'passes through a Doppler frequency shift frequency fading channel, obtaining an initial receiving signal r ═ Hs' + w, wherein H is a channel convolution matrix, w is a channel additive white Gaussian noise vector, and the receiving matrix of the OTFS-BFDM system is
Figure RE-GDA0003053199250000042
Wherein
Figure RE-GDA0003053199250000043
Is a SFFT transform, FNRepresenting a normalized N-point DFT matrix, wherein Q is a BFDM comprehensive filter coefficient matrix;
Figure RE-GDA0003053199250000044
wherein q (N) is a synthesis filter prototype window function of length L ═ MN, i ≦ 0 ≦ N-1;
further, the coefficient matrix Q of the BFDM synthesis filter is expressed as
Figure RE-GDA0003053199250000045
Obtaining an observation signal vector after a receiving signal r passes through an OTFS-BFDM system receiving matrix
Figure RE-GDA0003053199250000046
Figure RE-GDA0003053199250000047
Wherein,
Figure RE-GDA0003053199250000048
is HeffRepresenting channel effective moments of a systemThe number of the arrays is determined,
Figure RE-GDA0003053199250000049
in order to clip the noise, it is,
Figure RE-GDA00030531992500000410
is the channel noise;
or
Figure RE-GDA00030531992500000411
Wherein,
Figure RE-GDA00030531992500000412
is HeffA channel effective matrix representing the system is shown,
Figure RE-GDA00030531992500000413
in order to clip the noise, it is,
Figure RE-GDA00030531992500000414
is the channel noise.
Further, the step 3 specifically includes:
step 301, output variable signal vector
Figure RE-GDA0003053199250000059
Carrying out OTFS-BFDM modulation to obtain a new OTFS-BFDM signal;
step 302, after performing amplitude limiting processing on the new OTFS-BFDM signal, obtaining a first path of amplitude limiting processed signal
Figure RE-GDA0003053199250000051
Step 303, after the new OTFS-BFDM signal is attenuated, a second path of attenuated signal is obtained
Figure RE-GDA0003053199250000052
Step 304, limiting the first path of amplitude limiting partReason signal
Figure RE-GDA0003053199250000053
And the second path of attenuation processing signal
Figure RE-GDA0003053199250000054
Subtracting to obtain reconstructed clipping noise
Figure RE-GDA0003053199250000055
And 305, obtaining a reconstructed clipping noise estimate H δ 'at the receiver end by passing the reconstructed clipping noise δ' through a channel convolution matrix.
Further, the modified observation signal vector
Figure RE-GDA0003053199250000056
Calculated by the following formula:
Figure RE-GDA0003053199250000057
or
Figure RE-GDA0003053199250000058
Wherein δ - δ' is a residual clipping noise, obtained by calculating a difference between an initial clipping noise and a reconstructed clipping noise, obtained before an observed signal enters the detector, and further reduced in the next iteration.
A clipping noise elimination system based on peak-to-average ratio suppression applies the clipping noise elimination method, and the system comprises: the system comprises a transmitter and a receiver, wherein the transmitter is positioned at a transmitting end, the receiver is positioned at a receiving end, and the transmitter and the receiver are connected through a wireless communication link.
An electronic device comprising a memory unit having a computer program stored thereon and a processor unit implementing the above method when executing the program.
Through the embodiment of the application, the following technical effects can be obtained: the PAPR of the OTFS-BFDM signal is restrained by using a method of once amplitude limiting and filtering at a sending end, amplitude limiting noise is reconstructed at a receiving end, and the amplitude limiting noise is eliminated from an initial receiving signal as far as possible through an iteration mode, so that the accuracy of signal decoding is improved.
[ description of the drawings ]
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to the drawings without inventive labor.
FIG. 1 is a flow chart of the algorithm of the clipping noise cancellation method of the present invention;
FIG. 2 is a schematic diagram of the system components of the present invention;
FIG. 3 is a diagram of the PAPR complementary cumulative distribution function of the present invention;
fig. 4 is a schematic diagram of bit error rate simulation according to the present invention.
[ detailed description ] embodiments
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. 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 application.
The invention provides an amplitude limiting noise elimination scheme aiming at the peak-to-average power ratio inhibition of an OTFS-BFDM system based on the OTFS-BFDM system architecture, and the problem that the PAPR of the system is too high especially under the condition of a large data packet is considered. The invention uses a method of amplitude limiting and filtering at the sending end once, ensures the linear relation between the original signal and the amplitude limiting processing signal and reduces the PAPR of the system, and reduces the interference of the amplitude limiting noise to the signal decoding by a method of reconstructing the amplitude limiting noise and iteratively eliminating at the receiving end.
Fig. 1 is a flowchart of an algorithm of a clipping noise removing method according to the present invention, which is applied to a clipping noise removing system, and the clipping noise removing method includes the following steps:
step 1, at a sending end, carrying out primary amplitude limiting and filtering on an OTFS-BFDM modulation signal to obtain an amplitude limiting processing signal s';
when a Gaussian random signal enters the amplitude limiting device, the output signal of the Gaussian random signal can be statistically decomposed into the sum of two parts of uncorrelated signals, and the purpose of using one-time amplitude limiting and filtering is to keep the linear relation and filter out-of-band noise;
the performing primary amplitude limiting and filtering on the OTFS-BFDM modulated signal specifically includes:
the relation between the OTFS-BFDM modulation signal and the amplitude limiting processing signal s 'is expressed as s' ═ α s + δ, wherein s is the OTFS-BFDM modulation signal, α represents the amplitude limiting attenuation factor, and δ is the amplitude limiting noise vector;
the clipping attenuation factor α is calculated by the following formula:
Figure RE-GDA0003053199250000071
the signal of the sending end after amplitude limiting processing is
Figure RE-GDA0003053199250000072
Where d represents a modulation symbol vector, e.g., 4 QAM;
p is a block circulant matrix and,
Figure RE-GDA0003053199250000073
Λ is a diagonal matrix, Λ ═ diag (Λ)0,Λ1,…,ΛN-1) Go to and froObtained by the following formula:
Figure RE-GDA0003053199250000074
for each sub-matrix in Λ, the matrix Φ (i, j) is not null only if the i ═ j element is not equal to 0;
the OTFS-BFDM modulation signal is calculated through a transmission matrix of an OTFS-BFDM system, wherein the transmission matrix of the OTFS-BFDM system is
Figure RE-GDA0003053199250000075
Wherein
Figure RE-GDA0003053199250000076
Is the ISSFT transform and is,
Figure RE-GDA0003053199250000077
and IMRespectively representing a normalized N-point IDFT matrix and an M-dimensional identity matrix,
Figure RE-GDA0003053199250000078
representing the kronecker product, P is the filter coefficient matrix of the BFDM analysis, and P is represented by
Figure RE-GDA0003053199250000079
Where p (N) is an analysis filter prototype window function of length L ═ MN, 0 ≦ i ≦ N-1;
at a sending end, presetting the PAPR of the clipping noise elimination system, and defining the PAPR of a discrete time sample of a frame of OTFS-BFDM transmitting signal as:
Figure RE-GDA0003053199250000081
wherein s (l) is an output signal of the OTFS-BFDM transmitter in the time domain, and l is more than or equal to 0 and less than or equal to MN;
in practical application, theThe PAPR performance of a clipping noise cancellation system is measured by a complementary cumulative distribution function CCDF that calculates that the peak power ratio of each transmitted sample value exceeds a predefined threshold (PAPR)0) The complementary cumulative distribution function CCDF has statistical properties, and is calculated by the following formula:
CPAPR(PAPR0)＝Pr(PAPR＞PAPR0)＝1-Pr(PAPR≤PAPR0)＝1-(1-exp(-PAPR0))L
step 2, at a receiving end, after the attenuation of an initial receiving signal r is removed, an observation signal vector on a time domain is obtained through BFDM demodulation and octant-limited Fourier transform (SFFT)
Figure RE-GDA0003053199250000082
Will be provided with
Figure RE-GDA0003053199250000083
Substituting MP algorithm for channel equalization and decoding judgment, and outputting variable signal vector
Figure RE-GDA0003053199250000084
The performing attenuation-removing processing on the initial received signal r specifically includes:
after the amplitude limiting processing signal s 'passes through a Doppler frequency shift frequency fading channel, obtaining an initial receiving signal r ═ Hs' + w, wherein H is a channel convolution matrix, w is a channel additive white Gaussian noise vector, and the receiving matrix of the OTFS-BFDM system is
Figure RE-GDA0003053199250000085
Wherein
Figure RE-GDA0003053199250000086
Is a SFFT transform, FNRepresenting a normalized N-point DFT matrix, wherein Q is a BFDM comprehensive filter coefficient matrix;
Figure RE-GDA0003053199250000087
wherein q (N) is a synthesis filter prototype window function of length L ═ MN, i ≦ 0 ≦ N-1;
similarly, according to the method in step 1, Q can be expressed as
Figure RE-GDA0003053199250000088
Obtaining an observation signal vector after a receiving signal r passes through an OTFS-BFDM system receiving matrix
Figure RE-GDA0003053199250000089
Figure RE-GDA00030531992500000810
Wherein,
Figure RE-GDA00030531992500000811
is HeffA channel effective matrix representing the system is shown,
Figure RE-GDA0003053199250000091
in order to clip the noise, it is,
Figure RE-GDA0003053199250000092
is the channel noise;
or
Figure RE-GDA0003053199250000093
Wherein,
Figure RE-GDA0003053199250000094
is HeffA channel effective matrix representing the system is shown,
Figure RE-GDA0003053199250000095
in order to clip the noise, it is,
Figure RE-GDA0003053199250000096
is the channel noise;
in the above-mentioned calculation formula,
Figure RE-GDA0003053199250000097
proved to be sparsely connected, simultaneous multiplication with a diagonal matrix before and after it does not change the sparse connectivity, so HeffThe signal detection is also sparse and connected, so that the signal detection can be carried out by using an MP algorithm based on a factor graph; the system noise comprises amplitude limiting noise and channel noise, and the system defaults to use the channel noise as noise input of an MP detection algorithm when signal decoding is carried out, so that the decoding accuracy is influenced, the BER performance is reduced, and the amplitude limiting noise needs to be eliminated;
step 3, outputting the judgment output variable signal vector
Figure RE-GDA0003053199250000098
The OTFS-BFDM is modulated and then divided into two paths, one path is subjected to amplitude limiting and filtering processing which are the same as those of a sending end, so that a first path of amplitude limiting processing signal is obtained
Figure RE-GDA0003053199250000099
The other path is multiplied by a limiting attenuation factor to obtain a second path of attenuation processing signals
Figure RE-GDA00030531992500000910
Limiting the first path of amplitude-limiting processing signal
Figure RE-GDA00030531992500000911
And the second path of attenuation processing signal
Figure RE-GDA00030531992500000912
Subtracting to obtain a reconstructed amplitude limiting noise vector delta ', and obtaining a reconstructed amplitude limiting noise estimation H delta ' at the receiver end after the amplitude limiting noise vector delta ' passes through a channel convolution matrix;
the step 3 specifically includes:
step 301, output variable signal vector
Figure RE-GDA00030531992500000913
Carrying out OTFS-BFDM modulation to obtain a new OTFS-BFDM signal;
step 302, after performing amplitude limiting processing on the new OTFS-BFDM signal, obtaining a first path of amplitude limiting processed signal
Figure RE-GDA00030531992500000914
Step 303, after the new OTFS-BFDM signal is attenuated, a second path of attenuated signal is obtained
Figure RE-GDA00030531992500000915
Step 304, limiting the first path of amplitude limiting processing signal
Figure RE-GDA00030531992500000916
And the second path of attenuation processing signal
Figure RE-GDA00030531992500000917
Subtracting to obtain reconstructed clipping noise
Figure RE-GDA00030531992500000918
Step 305, obtaining a reconstructed clipping noise estimation H δ 'at the receiver end by passing the reconstructed clipping noise δ' through a channel convolution matrix;
step 4, subtracting the reconstructed clipping noise H delta' from the original received signal r to obtain a modified received signal r1The next iteration is performed on the modified received signal r ═ Hs '+ w-H δ ═ H' + w-H δ1Performing attenuation removal processing and OTFS-BFDM demodulation to obtain a corrected observation signal vector
Figure RE-GDA0003053199250000101
Wherein the modified observation signal vector
Figure RE-GDA0003053199250000102
Calculated by the following formula:
Figure RE-GDA0003053199250000103
or
Figure RE-GDA0003053199250000104
Wherein, δ - δ' is residual clipping noise obtained by calculating the difference between the initial clipping noise and the reconstructed clipping noise, and the residual clipping noise is obtained before the observed signal enters the detector and is further reduced in the next iteration;
step 5, the corrected received signal r1Replacing the initial received signal r, returning to the step 2 and repeatedly executing the step 2, and according to a preset maximum iteration time taumaxWhen the number of iterations reaches τmaxJumping out and finishing the amplitude limiting noise elimination;
fig. 2 is a schematic diagram of a system composition structure of the present invention, where the clipping noise canceling system includes two parts, i.e., a transmitter and a receiver, the transmitter is located at a transmitting end, the receiver is located at a receiving end, and the transmitter and the receiver are connected through a wireless communication link.
The transmitter performs ISSFT conversion, BFDM modulation, amplitude limiting and filtering processing at a transmitting end, and the receiver performs BFDM demodulation, octal finite Fourier transform (SFFT), ISFFT and BFDM modulation, amplitude limiting and filtering processing at a receiving end.
In the simulation experiments of the present invention, the delay-doppler spectrum parameters considered are shown in table i, where the power gain of each path is uniformly distributed.
Table I: delay-doppler spectrum parameter with path 5
Figure RE-GDA0003053199250000111
Table ii summarizes other relevant simulation parameters.
Table ii: simulation parameters
Figure RE-GDA0003053199250000112
Fig. 3 is a diagram illustrating PAPR complementary cumulative distribution function of the present invention, wherein OTFS-BFDM uses CCDF of PAPR of RRC window function. In order to better study the PAPR of the signal, the value of the oversampling factor is O-4. As shown in the figure, after the clipping process, the PAPR of the OTFS-BFDM signal is greatly reduced. When the CCDF probability is 10-3When the signal is processed, the PAPR of the signal adopting the amplitude limiting method is 1.015dB less than that of the SLM method and 4.38dB less than that of the original signal. In addition, as N increases, the CCDF of the signal PAPR also increases.
Fig. 4 is a schematic diagram of bit error rate simulation according to the present invention. In the invention, the BER performance of an OTFS-BFDM system adopting RRC under the condition that the Doppler frequency shift is 1935Hz is evaluated. It can be seen from the figure that OTFS-BFDM using the iterative clipping noise cancellation method has better and better BER performance as the number of iterations increases, since the residual clipping noise decreases as the number of iterations increases. Whether an iterative clipping noise cancellation method or an MP assisted clipping method is used (referred to as OTFS _ RCwithCN in the figure), the BER rate of the OTFS-BFDM system gets better as the clipping rate increases, since the higher the signal distortion, the smaller the signal distortion. While the latter allows for clipping noise as part of the system noise, the BER of systems employing the latter is generally greater than the former.
The invention discloses a method for eliminating amplitude limiting noise aiming at peak-to-average power ratio (PAPR) suppression in an OTFS-BFDM system. The method uses the amplitude limiting and filtering method to restrain the peak-to-average ratio of the OTFS-BFDM signal, reconstructs the amplitude limiting noise at the receiving end by using the same modulation and amplitude limiting method as the transmitting end, and reduces the residual quantity of the amplitude limiting noise in the initial receiving signal by an iterative elimination mode, thereby reducing the peak-to-average ratio of the OTFS-BFDM signal and improving the accuracy of system decoding. By comparing the PAPR and BER performance of the OTFS-BFDM system using the RRC window function under different methods, the method for amplitude limiting and filtering can better inhibit the PAPR than the SLM method, and the amplitude limiting noise elimination method aiming at the peak-to-average ratio inhibition has better BER performance than the MP auxiliary amplitude limiting method.
In some embodiments, part or all of the computer program may be loaded and/or installed onto the device via ROM. When being loaded and executed, may carry out one or more of the steps of the method described above.
The functions described herein above may be performed, at least in part, by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), an Application Specific Standard Product (ASSP), a system on a chip (SOC), a load programmable logic device (CPLD), and the like.
Program code for implementing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.
In the context of this disclosure, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
Further, while operations are depicted in a particular order, this should be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Under certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims (10)

1. A clipping noise elimination method based on peak-to-average power ratio suppression is applied to a clipping noise elimination system and is characterized by comprising the following steps:
step 1, at a sending end, carrying out primary amplitude limiting and filtering on an OTFS-BFDM modulation signal to obtain an amplitude limiting processing signal s';
step 2, at a receiving end, after the attenuation of an initial receiving signal r is removed, an observation signal vector on a time domain is obtained through BFDM demodulation and octane-limited Fourier transform (SFFT)
Figure RE-FDA0003007419440000011
Will be provided with
Figure RE-FDA0003007419440000012
Substituting MP algorithm for channel equalization and decoding judgment, and outputting variable signal vector
Figure RE-FDA0003007419440000013
Step 3, outputting the judgment output variable signal vector
Figure RE-FDA0003007419440000014
The OTFS-BFDM is modulated and then divided into two paths, one path is subjected to amplitude limiting and filtering processing which are the same as those of a sending end, so that a first path of amplitude limiting processing signal is obtained
Figure RE-FDA0003007419440000015
The other path is multiplied by a limiting attenuation factor to obtain a second path of attenuation processing signals
Figure RE-FDA0003007419440000016
Limiting the first path of amplitude-limiting processing signal
Figure RE-FDA0003007419440000017
And the second path of attenuation processing signal
Figure RE-FDA0003007419440000018
Subtracting to obtain a reconstructed clipping noise vector δ ', and after passing through a channel convolution matrix, obtaining a reconstructed clipping noise estimate h δ' at the receiver end;
step 4, subtracting the reconstructed clipping noise Η δ' from the initial received signal r to obtain a modified received signal r1The next iteration is performed on the modified received signal r ═ Hs '+ w-H δ ═ H' + w-H δ1Performing attenuation removal processing and OTFS-BFDM demodulation to obtain a corrected observation signal vector
Figure RE-FDA0003007419440000019
Step 5, the corrected received signal r1Replacing the initial received signal r, returning to the step 2 and repeatedly executing the step 2, and according to a preset maximum iteration time taumaxWhen the number of iterations reaches τmaxAnd then jumping out and finishing the amplitude limiting noise elimination.
2. The clipping noise removing method according to claim 1, wherein the clipping and filtering the OTFS-BFDM modulated signal for one time specifically includes:
the relation between the OTFS-BFDM modulation signal and the amplitude limiting processing signal s 'is expressed as s' ═ α s + δ, wherein s is the OTFS-BFDM modulation signal, α represents the amplitude limiting attenuation factor, and δ is the amplitude limiting noise vector;
the clipping attenuation factor α is calculated by the following formula:
Figure RE-FDA0003007419440000021
the signal of the sending end after amplitude limiting processing is
Figure RE-FDA0003007419440000022
Wherein d represents a modulation symbol vector;
p is a block circulant matrix and,
Figure RE-FDA0003007419440000023
Λ is a diagonal matrix, Λ ═ diag (Λ)0,Λ1,L,ΛN-1) And is obtained by the following formula:
Figure RE-FDA0003007419440000024
for each sub-matrix in Λ, the matrix Φ (i, j) is not empty only if the i ═ j element is not equal to 0.
3. The clipping noise cancellation method according to claim 2, wherein the OTFS-BFDM modulated signal is calculated by a transmission matrix of an OTFS-BFDM system, the transmission matrix of the OTFS-BFDM system being
Figure RE-FDA0003007419440000025
Wherein
Figure RE-FDA0003007419440000026
Is the ISSFT transform and is,
Figure RE-FDA0003007419440000027
and IMRespectively representing a normalized N-point IDFT matrix and an M-dimensional identity matrix,
Figure RE-FDA0003007419440000028
representing the kronecker product, P is the filter coefficient matrix of the BFDM analysis, and P is represented by
Figure RE-FDA0003007419440000029
Where p (N) is an analysis filter prototype window function of length L ═ MN, 0 ≦ i ≦ N-1.
4. The clipping noise cancellation method according to one of claims 1 to 3,
presetting the PAPR of the clipping noise elimination system, and defining the PAPR of discrete time samples of a frame of OTFS-BFDM transmitting signals as follows:
Figure RE-FDA00030074194400000210
wherein s (l) is an output signal of the OTFS-BFDM transmitter in the time domain, and l is more than or equal to 0 and less than or equal to MN;
the PAPR performance of the clipping noise cancellation system is measured by a complementary cumulative distribution function CCDF that calculates that the peak power ratio of each transmitted sample value exceeds a predefined threshold (PAPR)0) The complementary cumulative distribution function CCDF has statistical properties, and is calculated by the following formula:
CPAPR(PAPR0)＝Pr(PAPR＞PAPR0)＝1-Pr(PAPR≤PAPR0)＝1-(1-exp(-PAPR0))L。
5. the clipping noise removing method according to claim 1, wherein the performing the de-attenuation process on the initial received signal r specifically includes:
after the amplitude limiting processing signal s 'passes through a Doppler frequency shift frequency fading channel, obtaining an initial receiving signal r ═ Hs' + w, wherein H is a channel convolution matrix, w is a channel additive white Gaussian noise vector, and the receiving matrix of the OTFS-BFDM system is
Figure RE-FDA0003007419440000031
Wherein
Figure RE-FDA0003007419440000032
Is a SFFT transform, FNRepresenting a normalized N-point DFT matrix, wherein Q is a BFDM comprehensive filter coefficient matrix;
Figure RE-FDA0003007419440000033
where q (N) is the synthesis filter prototype window function with length L ═ MN, 0 ≦ i ≦ N-1.
6. The clipping noise cancellation method according to claim 5, wherein the BFDM synthesis filter coefficient matrix Q is expressed as
Figure RE-FDA0003007419440000034
Obtaining an observation signal vector after a receiving signal r passes through an OTFS-BFDM system receiving matrix
Figure RE-FDA0003007419440000035
Figure RE-FDA0003007419440000036
Wherein,
Figure RE-FDA0003007419440000037
is HeffA channel effective matrix representing the system is shown,
Figure RE-FDA0003007419440000038
in order to clip the noise, it is,
Figure RE-FDA0003007419440000039
is the channel noise;
or
Figure RE-FDA00030074194400000310
Wherein,
Figure RE-FDA00030074194400000311
is HeffA channel effective matrix representing the system is shown,
Figure RE-FDA0003007419440000041
in order to clip the noise, it is,
Figure RE-FDA0003007419440000042
is the channel noise.
7. The clipping noise removing method according to claim 1, wherein the step 3 specifically includes:
step 301, output variable signal vector
Figure RE-FDA0003007419440000043
Carrying out OTFS-BFDM modulation to obtain a new OTFS-BFDM signal;
step 302, after performing amplitude limiting processing on the new OTFS-BFDM signal, obtaining a first path of amplitude limiting processed signal
Figure RE-FDA0003007419440000044
Step 303, after the new OTFS-BFDM signal is attenuated, a second path of attenuated signal is obtained
Figure RE-FDA0003007419440000045
Step 304, limiting the first path of amplitude limiting processing signal
Figure RE-FDA0003007419440000046
And the second path of attenuation processing signal
Figure RE-FDA0003007419440000047
Subtracting to obtain reconstructed clipping noise
Figure RE-FDA0003007419440000048
Step 305, obtaining a reconstructed clipping noise estimate h δ 'at the receiver end by passing the reconstructed clipping noise δ' through a channel convolution matrix.
8. The clipping noise cancellation method according to claim 1, wherein the modified observation signal vector is
Figure RE-FDA0003007419440000049
Calculated by the following formula:
Figure RE-FDA00030074194400000410
or
Figure RE-FDA00030074194400000411
Wherein δ - δ' is a residual clipping noise, obtained by calculating a difference between an initial clipping noise and a reconstructed clipping noise, obtained before an observed signal enters the detector, and further reduced in the next iteration.
9. A clipping noise removing system based on peak-to-average ratio suppression, which applies the clipping noise removing method according to one of the claims 1 to 8, wherein the system comprises two parts, a transmitter and a receiver, the transmitter is located at a transmitting end, the receiver is located at a receiving end, and the transmitter and the receiver are connected through a wireless communication link.
10. An electronic device comprising a memory unit and a processor unit, the memory unit having stored thereon a computer program, characterized in that the processor unit, when executing the program, implements the method according to one of claims 1 to 8.
CN202011544946.6A 2020-12-24 2020-12-24 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment Pending CN112968852A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202011544946.6A CN112968852A (en) 2020-12-24 2020-12-24 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment
CN202111046326.4A CN113489666B (en) 2020-12-24 2021-09-08 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011544946.6A CN112968852A (en) 2020-12-24 2020-12-24 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment

Publications (1)

Publication Number Publication Date
CN112968852A true CN112968852A (en) 2021-06-15

Family

ID=76271656

Family Applications (2)

Application Number Title Priority Date Filing Date
CN202011544946.6A Pending CN112968852A (en) 2020-12-24 2020-12-24 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment
CN202111046326.4A Active CN113489666B (en) 2020-12-24 2021-09-08 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment

Family Applications After (1)

Application Number Title Priority Date Filing Date
CN202111046326.4A Active CN113489666B (en) 2020-12-24 2021-09-08 Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment

Country Status (1)

Country Link
CN (2) CN112968852A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113556306A (en) * 2021-07-19 2021-10-26 上海交通大学 Discrete Fourier transform extended orthogonal time-frequency-space modulation method
CN114189261A (en) * 2021-11-02 2022-03-15 广州慧睿思通科技股份有限公司 Time-frequency graph processing method and device, network equipment and computer readable storage medium

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116366169B (en) * 2023-06-01 2023-10-24 浙江大学 Ultrasonic channel modeling method, electronic device and storage medium

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102697299B1 (en) * 2015-09-07 2024-08-23 코히어 테크널러지스, 아이엔씨. Multiple access using orthogonal time-frequency spatial modulation
CN106130946A (en) * 2016-06-08 2016-11-16 重庆邮电大学 A kind of biorthogonal frequency-division multiplex multi-carrier modulation/demodulation methods and system
CN111555780A (en) * 2020-01-09 2020-08-18 北京邮电大学 Multi-antenna receiver design based on orthogonal time-frequency-space modulation

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113556306A (en) * 2021-07-19 2021-10-26 上海交通大学 Discrete Fourier transform extended orthogonal time-frequency-space modulation method
CN113556306B (en) * 2021-07-19 2022-04-08 上海交通大学 Discrete Fourier transform extended orthogonal time-frequency-space modulation method and system
CN114189261A (en) * 2021-11-02 2022-03-15 广州慧睿思通科技股份有限公司 Time-frequency graph processing method and device, network equipment and computer readable storage medium

Also Published As

Publication number Publication date
CN113489666A (en) 2021-10-08
CN113489666B (en) 2021-11-30

Similar Documents

Publication Publication Date Title
CN113489666B (en) Amplitude limiting noise elimination method and system based on peak-to-average ratio inhibition and electronic equipment
CN103457638B (en) Restraining device and restraining method for burst impulse noise of power line communication channel
CN106506042B (en) Based on L1/2The electric line communication system impulse noise suppression method of norm regularization
CN101771652B (en) Amplitude limiting reserved sub carrier wave reduction PAPR method and system based on amplitude proportion factors
CN105072072B (en) A kind of OFDM-TDCS waveform design methods of low PAPR
CN107528806B (en) SACI-TR algorithm for reducing peak-to-average ratio of FBMC-OQAM
WO2009070441A1 (en) Digital pre-distortion for orthogonal frequency division multiplexing (ofdm) signals
US20070258528A1 (en) Apparatus for reducing clipping noise in a broadband wireless communication system and method thereof
CN113259298B (en) OTFS signal processing method, device, equipment and storage medium
Wang et al. Compensation of nonlinear distortions with memory effects in OFDM transmitters
Padarti et al. An improved ASOICF algorithm for PAPR reduction in OFDM systems
CN101414994A (en) Method and apparatus for reducing peak average power ratio of multi-carrier system
CN107426129B (en) Method and device for modulating and demodulating GFDM signal
Ikni et al. PAPR reduction in FBMC-OQAM systems based on discrete sliding norm transform technique
JP6278499B2 (en) Peak power reduction device in communication system
TWI383610B (en) Method for detecting a signal, detector and computer program product
CN109155769B (en) Clipping method and device for orthogonal frequency division multiplexing
CN106789814A (en) A kind of low complex degree SLM algorithms of reduction FBMC OQAM systems PAPR
CN101662447B (en) Process method of despiking and device thereof
CN108881095B (en) OFDM data processing method and device
Lajnef et al. The Nonlinear Distortion cancellation for the effect of HPA nonlinearities in filter bank based multi-carrier (FBMC) for Cognitive Radio systems
KR101740441B1 (en) Apparatus and method for interference cancellation in wireless communication system
CN117134783B (en) Pre-compensation method and device for transmitter signal, electronic equipment and storage medium
CN117155753B (en) Peak clipping method and system for reducing peak-to-average ratio of transmitter
CN115801528B (en) OTFS waveform peak-to-average ratio suppression method based on time delay grid grouping

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
WD01 Invention patent application deemed withdrawn after publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20210615