CN117319159A - fVD-based high-speed mobile scene windowing OFDM communication method - Google Patents

fVD-based high-speed mobile scene windowing OFDM communication method Download PDF

Info

Publication number
CN117319159A
CN117319159A CN202311245802.4A CN202311245802A CN117319159A CN 117319159 A CN117319159 A CN 117319159A CN 202311245802 A CN202311245802 A CN 202311245802A CN 117319159 A CN117319159 A CN 117319159A
Authority
CN
China
Prior art keywords
windowing
ofdm communication
communication system
frequency
module
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
CN202311245802.4A
Other languages
Chinese (zh)
Inventor
王靖
张旗
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.)
Sun Yat Sen University
Original Assignee
Sun Yat Sen University
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 Sun Yat Sen University filed Critical Sun Yat Sen University
Priority to CN202311245802.4A priority Critical patent/CN117319159A/en
Publication of CN117319159A publication Critical patent/CN117319159A/en
Pending legal-status Critical Current

Links

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
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2628—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators
    • 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
    • H04L27/2602—Signal structure
    • H04L27/2605—Symbol extensions, e.g. Zero Tail, Unique Word [UW]
    • H04L27/2607—Cyclic extensions
    • 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
    • H04L27/2649—Demodulators
    • H04L27/265—Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators
    • 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
    • H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
    • H04L27/2691—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation involving interference determination or cancellation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/30—Services specially adapted for particular environments, situations or purposes
    • H04W4/40—Services specially adapted for particular environments, situations or purposes for vehicles, e.g. vehicle-to-pedestrians [V2P]
    • H04W4/42—Services specially adapted for particular environments, situations or purposes for vehicles, e.g. vehicle-to-pedestrians [V2P] for mass transport vehicles, e.g. buses, trains or aircraft
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Discrete Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

The invention discloses a high-speed mobile scene windowing OFDM communication method based on FVVD, and relates to the technical field of wireless communication. The method comprises the following steps: at the transmitting end of the windowed OFDM communication system, carrying out serial-parallel conversion on N transmitting symbols, and then carrying out N-point inverse fast Fourier transform to obtain a time domain continuous signal x (t); adding a cyclic prefix after windowing the time domain continuous signal x (t), and transmitting the time domain continuous signal x (t) to a double-selective channel through an antenna; wherein, an Slepian window is adopted as a window function when the windowing operation is carried out; removing cyclic prefix from received channel output, performing serial-parallel conversion, and performing N-point fast Fourier transform to obtain discrete frequency domain received signals; and performing symbol detection on the frequency domain received signal by adopting a frequency-varying Viterbi detection algorithm, and obtaining a received symbol through parallel-serial conversion. Compared with the prior art, the invention improves the interference elimination capability of FVVD, reduces the residual ICI in the detection process, and can obtain better FER performance.

Description

fVD-based high-speed mobile scene windowing OFDM communication method
Technical Field
The invention relates to the technical field of wireless communication, in particular to a high-speed mobile scene windowing OFDM communication method based on FVVD.
Background
Orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) is a core modulation technique for fourth and fifth generation mobile communications, and is of great interest for its high spectral efficiency, flexible resource allocation, and strong resistance to frequency selective interference. However, the conventional CP-OFDM based on Cyclic Prefix (CP) is severely degraded in a high-speed wireless communication scenario (e.g., high-speed railway communication), and cannot fully meet the requirements of the next-generation communication system.
In a high speed scenario, the wireless channel is typically a dual selective fading channel. The dual selective fading channel causes very high inter-subcarrier interference (inter-carrier interferences, ici), i.e. severe interference to adjacent subcarriers. In order to solve ICI, the existing methods can be mainly divided into two categories, ICI self-cancellation and ICI suppression; the former mainly includes paired data modulation, frequency domain filtering and time windowing, and the latter mainly includes viterbi detection and iterative equalization. However, when more OFDM subcarriers are involved, the existing methods face extremely high complexity, which makes them difficult to use in practical applications; furthermore, these methods have limited interference cancellation capability in high doppler scenarios, which may lead to residual ICI problems.
In a dual selective fading channel, ICI resulting from fractional doppler shift is distributed over almost all subcarriers. By selecting a suitable window function, windowed OFDM can limit ICI between several adjacent subcarriers, so that the input-output equivalent channel matrix has sparse and band-limited characteristics, which is an application condition of a Frequency-dependent viterbi detection (fvd) algorithm, and can greatly reduce processing complexity of a receiving end. However, fvd only considers raised cosine roll-off window, its interference cancellation capability is limited, and there is more residual ICI in high doppler scene, resulting in reduced performance of detecting Frame Error Rate (FER) and even serious Error floor, so the practical value is not high.
Disclosure of Invention
The invention provides a high-speed mobile scene windowing OFDM communication method based on FVVD, which aims to overcome the defects that the FVVD algorithm in the dual-selective fading channel has limited interference elimination capability and more residual ICI in the prior art.
In order to solve the technical problems, the technical scheme of the invention is as follows:
in a first aspect, a fvd-based high speed mobile scene windowing OFDM communication method includes:
at the transmitting end of a windowed OFDM communication system:
performing serial-parallel conversion on N sending symbols, and then performing N-point inverse fast Fourier transform to obtain a time domain continuous signal x (t);
adding a cyclic prefix after windowing the time domain continuous signal x (t), and transmitting the time domain continuous signal x (t) to a double-selective channel through an antenna; wherein, an Slepian window is adopted as a window function when the windowing operation is carried out;
at the receiving end of the windowed OFDM communication system:
removing cyclic prefix from received channel output, performing serial-parallel conversion, and performing N-point fast Fourier transform to obtain discrete frequency domain received signals;
and performing symbol detection on the frequency domain received signal by adopting a frequency-varying Viterbi detection algorithm, and obtaining a received symbol through parallel-serial conversion.
The high-speed mobile scene windowing OFDM communication system based on the FVVD comprises a transmitting end and a receiving end, wherein the transmitting end is in communication connection with the receiving end through an antenna, and the transmitting end comprises a serial-parallel conversion module, an inverse fast Fourier transform module, a windowing module, a parallel-serial conversion module and a cyclic prefix adding module which are sequentially connected; the receiving end comprises a cyclic prefix removal module, a serial-parallel conversion module, a fast Fourier transform module, a frequency-variable Viterbi detection module and a parallel-serial conversion module which are connected in sequence;
when the windowing module operates, the window function is used for windowing the time domain continuous signal by using the Slepian window; the OFDM communication system employs dual selective channels.
Compared with the prior art, the technical scheme of the invention has the beneficial effects that: the invention discloses a high-speed mobile scene windowing OFDM communication method based on FVVD, which improves interference elimination capability and reduces residual ICl in a detection process by adopting an Slepian window as a window function. Compared with the prior art, the invention can obtain better FER performance, and can be better suitable for high carrier frequency communication under a high-speed moving scene, such as using 5G (Fifth Generation) mobile communication on a high-speed railway.
Drawings
Fig. 1 is a flow chart of a windowed OFDM communication method according to embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a design flow of an optimal window function in embodiment 1 of the present invention;
FIG. 3 is a time domain waveform diagram of an Slepian window of example 1 of the present invention;
FIG. 4 is a spectrum of an Slepian window of example 1 of the present invention;
fig. 5 is a schematic structural diagram of a windowed OFDM communication system according to embodiment 2 of the present invention;
fig. 6 is a diagram showing FER curve based on the viterbi detection algorithm in accordance with embodiment 3 of the present invention.
Detailed Description
The terms first, second and the like in the description and in the claims of the present application and in the above-described figures, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and are merely illustrative of the manner in which the embodiments of the application described herein have been described for objects of the same nature. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The drawings are for illustrative purposes only and are not to be construed as limiting the present patent;
for the purpose of better illustrating the embodiments, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the actual product dimensions;
it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The technical scheme of the invention is further described below with reference to the accompanying drawings and examples.
Example 1
The present embodiment proposes a fvd-based high-speed mobile scene windowing OFDM communication method, referring to fig. 1, including:
at the transmitting end of a windowed OFDM communication system:
performing serial-parallel conversion on N sending symbols, and then performing N-point inverse fast Fourier transform to obtain a time domain continuous signal x (t);
adding a cyclic prefix after windowing the time domain continuous signal x (t), and transmitting the time domain continuous signal x (t) to a double-selective channel through an antenna; wherein, an Slepian window is adopted as a window function when the windowing operation is carried out;
at the receiving end of the windowed OFDM communication system:
removing cyclic prefix from received channel output, performing serial-parallel conversion, and performing N-point fast Fourier transform to obtain discrete frequency domain received signals;
and performing symbol detection on the frequency domain received signal by adopting a frequency-varying Viterbi detection algorithm, and obtaining a received symbol through parallel-serial conversion.
In a preferred embodiment, at the transmitting end of the windowed OFDM communication system, every N serial transmission symbolsTo convert into a group of parallel symbols and then to make N-point inverse fast Fourier transform (Inverse Fast Fourier Transform, IFFT) to obtain time domain continuous signal x (t), namely
Where Δf represents the subcarrier spacing, T represents the OFDM symbol duration, both satisfying tΔf=1. Multiplying x (T) by window function u (T) of duration T to obtain x u (t) =x (t) ·u (t) and then adding a Cyclic Prefix (CP), and transmitting the Cyclic Prefix (CP) to a receiving end through an antenna.
Consider a dual selective channel comprising L independent scattering components, each independent scattering component having a fading coefficient h l Time delay of tau l Doppler shift f l The channel outputs are as follows
Where v (t) is typically additive white gaussian noise.
In an alternative embodiment, at a receiving end of the windowed OFDM communication system, after removing a cyclic prefix and performing serial-to-parallel conversion on a receiving channel output, performing N-point fast fourier transform (Fast Fourier Transform, FFT) to obtain a discrete frequency domain received signal as follows:
therefore, the input/output of the windowed OFDM communication system satisfies the following relation
In the method, in the process of the invention,respectively representing a transmitting symbol and a receiving symbol on a kth subcarrier, wherein k is more than or equal to 0 and less than N; />Representing a time delay tau at the kth subcarrier l The frequency offset is f l Frequency domain sample values of a window function, i.ep > 0, indicated in the calculation +.>Time-to-window function frequency domain response +.>A cut-off range of the side lobe; Δf represents a subcarrier spacing satisfying tΔf=1, and T represents an OFDM symbol duration;/>representing independent co-distributed additive gaussian noise. k' is a sequence number index of a subcarrier affecting the received signal on the kth subcarrier.
In this embodiment, the window function is a window function in which the side lobe level is rapidly attenuated, and thus only calculation is performedResponses in the (-pΔf, pΔf) range; p > 0 is represented in the calculation +.>Time-to-window function frequency domain response +.>And the cut-off range of the side lobe.
Further, let the transmission symbols and the reception symbols in the frequency domain be:
wherein,respectively representing a transmitting symbol and a receiving symbol on a kth subcarrier, wherein k is more than or equal to 0 and less than N;
it may be noted that the input and output of a windowed OFDM communication system is related toAnd->Is therefore abbreviated as matrix form
Wherein the method comprises the steps ofRepresenting a frequency domain equivalent channel matrix with a bandwidth q; q=2p+1.
It should be noted that the sidelobe level of the rapid decay of the window function may be such thatThe method has the characteristics of sparseness and band limitation, so that a frequency-variable Viterbi detection algorithm can be adopted to detect data.
In the present embodiment, for a given constraint length q=2p+1, subcarrier spacing Δf, and maximum doppler shift f D Window function spectrumThe energy of (2) should be as concentrated as possible
|f|＜pΔf-f D
Only in this way can the residual ICI at detection be minimized and the effective signal maximized.
When (when)Is concentrated in the region |f| < pΔf-f D The energy in is maximum, then u (t) is the optimal window function design.
Further, given a constant Ω > 0, u (t) is an absolute square integrable function in the real domain,fourier transform of u (t) such that the functional
The maximized u (t) is the integral equation
Of all solutions, the one that maximizes λ. Those skilled in the art will appreciate that all solutions to this integral equation are collectively referred to as the long ellipsoidal wave function (prolate spheroidal wave functions), also known as the Slepian function. Only let Ω=pΔf-f D Solving the integral equation to obtain a solution u (t) corresponding to the maximum lambda, and obtaining an optimal window function, see fig. 2.
It should be noted that, in this embodiment, the spectrum of the optimal window function can be concentrated in the region corresponding to the given constraint length and the maximum doppler shift as much as possible, so as to minimize the residual ICI during detection, maximize the energy of the effective signal, and enable better FER performance.
The embodiment discloses that the upper bound of the FER performance of the window function when the windowed OFDM communication system uses the frequency-variable Viterbi detection algorithm to detect symbols is a supplement to the theoretical analysis of the frequency-variable Viterbi detection algorithm, the energy of the optimal window function is concentrated in the bandwidth area corresponding to the constraint length more, the residual ICI in the detection process is lower, the FER performance can be improved, and the out-of-band leakage of the communication system can be reduced.
In some examples, consider a high doppler shift scene, such as f D If a raised cosine roll-off window is used, the frequency-variant viterbi symbol detection FER at q=3 has poor performance, and even a significant error floor occurs. This is because the raised cosine roll-off window has not been able to constrain most of the ICI to within 3 sub-carriers when the doppler shift reaches 10kHz, so that a large residual ICI exists for q=3 frequency-dependent viterbi symbol detection. If the designed Slepian window is adopted, the FER when the transmission signal-to-noise ratio is larger can be more than one order of magnitude lower than the raised cosine roll-off window due to lower residual ICI in the detection process, and the error leveling effect is slowed down.
In some examples, f D Let q=5, Ω=pΔf-f, =10 kHz D =20khz, constructing the corresponding Slepian window, the resulting u (t) sumAs shown in fig. 3 and 4, it can be seen that the main energy of the window function is substantially concentrated at [ - Ω, Ω]Inside (within the two vertical dashed lines in fig. 4).
Example 2
The embodiment provides a fvd-based high-speed mobile scene windowing OFDM communication system, referring to fig. 5, and the method described in application embodiment 1 includes a transmitting end and a receiving end, where the transmitting end is connected with the receiving end through an antenna in a communication manner, and the transmitting end includes a serial-parallel conversion module, an inverse fast fourier transform module, a windowing module, a parallel-serial conversion module, and a cyclic prefix module that are sequentially connected; the receiving end comprises a cyclic prefix removal module, a serial-parallel conversion module, a fast Fourier transform module, a frequency-variable Viterbi detection module and a parallel-serial conversion module which are connected in sequence;
when the windowing module operates, the window function is used for windowing the time domain continuous signal by using the Slepian window; the OFDM communication system employs dual selective channels.
In a preferred embodiment, the dual selective channel comprises L independent scattering components, the fading coefficient of the independent scattering component is h l Time delay of tau l Doppler shift of f l The method comprises the steps of carrying out a first treatment on the surface of the The channel outputs of the dual selective channels are:
where v (t) represents typical additive white gaussian noise; x is x u (t) =x (t) ·u (t) represents the output of the time domain continuous signal x (t) after processing by the windowing module.
In an alternative embodiment, in the windowed OFDM communication system, the input of the transmitting end and the output of the receiving end satisfy the following relation:
in the method, in the process of the invention,respectively representing a transmitting symbol and a receiving symbol on a kth subcarrier, wherein k is more than or equal to 0 and less than N; />Representing a time delay tau at the kth subcarrier l The frequency offset is f l Frequency domain sample values of a window function, i.ep > 0, indicated in the calculation +.>Time-to-window function frequency domain response +.>A cut-off range of the side lobe; Δf represents a subcarrier spacing satisfying tΔf=1, and T represents an OFDM symbol duration; />Representing independent co-distributed additive gaussian noise.
Further, the input-output relationship of the windowed OFDM communication system is abbreviated as a matrix form:
in the method, in the process of the invention,representing a frequency domain equivalent channel matrix with a bandwidth q, q=2p+1; />
When the frequency-domain received signal is subjected to symbol detection by adopting the frequency-varying Viterbi detection algorithm, q is set to be less than or equal to 5.
Further, the parameter Ω=pΔf-f is defined D In the windowing module, the window function u (t) is an integral equation
One of all solutions that maximizes λ;
wherein f D Indicating the maximum doppler shift.
It will be appreciated that the system of this embodiment corresponds to the method of embodiment 1 described above, and the alternatives in embodiment 1 described above are equally applicable to this embodiment, so that the description will not be repeated here.
Example 3
The windowed OFDM communication method proposed by embodiment 1 and/or the windowed OFDM communication system proposed by embodiment 2 are applied to this embodiment, and a 3GPP TR 38.901 protocol TDL-A model is adopted for simulation, so as to set the delay spread of a channel to D s =300 ns, maximum doppler shift considering f D =2khz and f D =10khz, specific parameter configurations are shown in table 1:
table 1 windowed OFDM communication system simulation parameter configuration
FIG. 6 shows FER performance at different normalized Doppler shifts and different constraint lengths, as can be seen for f D Δf=0.13, i.e. f D =2khz, the Slepian window can obtain better FER performance and phase no matter constraint length q=3 or q=5, the Slepian window can obtain better FER performance and phaseThis is not so great because OFDM ICl is essentially constrained to be within 3 contiguous sub-carriers under the action of the Slepian window, so q=3 is sufficient to handle the vast majority of ICl at this time. FIG. 6 also shows the maximum likelihood detector lower bound (Lower Bound of Maximum Likelihood Detector, LB-MLD), labeled "f D Δf=0.13, LB-MLD "and" f D /Δf=0.67, LB-MLD). By comparison, it can be found that fvd algorithm performance at q=5 is already very close to that of the optimal MLD.
Note that, general MLD is of exponential complexity, and it is almost impossible to directly implement maximum likelihood detection for n=128 used in simulation. In fact, the MLD lower bound curve is generated as follows: is provided withAnd->Representing the actually transmitted OFDM symbol and the detection output result, respectively, each time a detection error occurs in the simulation of q=5, namelyIf->Likelihood function value of greater than +.>The MLD in this case must also be erroneous. By counting the frequency of occurrence of the events, a lower bound for the error rate of the MLD can be obtained.
Preferably, q=5 is chosen instead of q=3 to calculate the MLD lower bound, since q=5 gives a tighter lower bound because of the greater probability of occurrence of the event. For f D Δf=0.67, i.e. f D Because ICI is very large, FER performance for q=3 drops significantly, q=5 still shows performance approaching maximum likelihood detection. But when q=3 and snr=35 dB,the FER of the Slepian window is more than one order of magnitude lower than that of the raised cosine roll-off window, and the main reason is that the residual ICI of the Slepian window in the detection process is lower, which shows that the FVVD algorithm can be more suitable for a high Doppler frequency shift scene by adopting the Slepian window.
The same or similar reference numerals correspond to the same or similar components;
the terms describing the positional relationship in the drawings are merely illustrative, and are not to be construed as limiting the present patent;
all parts of the specification are described in a progressive manner, and all parts of the embodiments which are the same and similar to each other are referred to each other, and each embodiment is mainly described as being different from other embodiments. In particular, for apparatus and system embodiments, the description is relatively simple, as it is substantially similar to method embodiments, with reference to the description of the method embodiments section. It is to be understood that the above examples of the present invention are provided by way of illustration only and not by way of limitation of the embodiments of the present invention. It will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made, and the functional modules or units can be integrated together to form a single unit, or the modules can reside individually or two or more modules can be integrated to form a single unit. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.
The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. The storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes one or more integration of the available media. The usable medium may be a magnetic medium, an optical medium, a semiconductor medium, or the like. The magnetic medium may be a floppy disk, a hard disk, or a magnetic tape. The optical medium may be a digital versatile disc (digital versatiledisc, DVD). The semiconductor medium may be a Solid State Disk (SSD).

Claims (10)

1. A fvd-based high speed mobile scene windowing OFDM communication method, comprising:
at the transmitting end of a windowed OFDM communication system:
performing serial-parallel conversion on N sending symbols, and then performing N-point inverse fast Fourier transform to obtain a time domain continuous signal x (t);
adding a cyclic prefix after windowing the time domain continuous signal x (t), and transmitting the time domain continuous signal x (t) to a double-selective channel through an antenna; wherein, an Slepian window is adopted as a window function when the windowing operation is carried out;
at the receiving end of the windowed OFDM communication system:
removing cyclic prefix from received channel output, performing serial-parallel conversion, and performing N-point fast Fourier transform to obtain discrete frequency domain received signals;
and performing symbol detection on the frequency domain received signal by adopting a frequency-varying Viterbi detection algorithm, and obtaining a received symbol through parallel-serial conversion.
2. The fvd-based high speed mobile scene windowing OFDM communication method according to claim 1, wherein the dual selective channel comprises L independent scattering components, and the fading coefficient of the independent scattering component is h l Time delay of tau l Doppler shift of f l The method comprises the steps of carrying out a first treatment on the surface of the The channel outputs of the dual selective channels are:
where v (t) represents typical additive white gaussian noise; x is x u (t) =x (t) ·u (t) representing the time-domain continuous signal after the windowing operation.
3. The fvd-based high speed moving scene windowing OFDM communication method according to claim 2, wherein the input/output of the windowing OFDM communication system satisfies the following relationship:
in the method, in the process of the invention,representing the transmitted symbols and received symbols on the kth subcarrier, respectively, 0.ltoreq.k<N；/>Representing a time delay tau at the kth subcarrier l The frequency offset is f l Frequency domain sample values of a window function, i.ep>0, indicated in the calculation->Time-to-window function frequency domain response +.>A cut-off range of the side lobe; Δf represents a subcarrier spacing satisfying tΔf=1, and T represents an OFDM symbol duration; />Representing independent co-distributed additionsGaussian noise.
4. A fvd-based high speed moving scene windowing OFDM communication method according to claim 3, wherein the input-output relationship of the windowing OFDM communication system is abbreviated as a matrix form:
in the method, in the process of the invention,representing a frequency domain equivalent channel matrix with a bandwidth q, q=2p+1; />
When the frequency-domain received signal is subjected to symbol detection by adopting the frequency-varying Viterbi detection algorithm, q is set to be less than or equal to 5.
5. A fvd-based high speed mobile scene windowing OFDM communication method according to any of claims 3-4, wherein: definition parameter Ω=pΔf-f D The window function u (t) is an integral equation
One of all solutions that maximizes λ;
wherein f D Indicating the maximum doppler shift.
6. The utility model provides a high-speed mobile scene windowing OFDM communication system based on FVVD, includes transmitting end and receiving end, the transmitting end with the receiving end is through antenna communication connection, its characterized in that:
the transmitting end comprises a serial-parallel conversion module, an inverse fast Fourier transform module, a windowing module, a parallel-serial conversion module and a cyclic prefix adding module which are connected in sequence;
the receiving end comprises a cyclic prefix removal module, a serial-parallel conversion module, a fast Fourier transform module, a frequency-variable Viterbi detection module and a parallel-serial conversion module which are connected in sequence;
when the windowing module operates, the window function is used for windowing the time domain continuous signal by using the Slepian window; the OFDM communication system employs dual selective channels.
7. The fvd-based high speed mobile scene windowing OFDM communication system as claimed in claim 6, wherein the dual selective channel comprises L independent scattering components, the fading coefficient of the independent scattering component is h l Time delay of tau l Doppler shift of f l The method comprises the steps of carrying out a first treatment on the surface of the The channel outputs of the dual selective channels are:
where v (y) represents typical additive white gaussian noise; x is x u (t) =x (t) ·u (t) represents the output of the time domain continuous signal x (t) after processing by the windowing module.
8. The fvd-based high speed mobile scene windowing OFDM communication system according to claim 7, wherein the input of the transmitting end and the output of the receiving end satisfy the following relation in the windowing OFDM communication system:
in the method, in the process of the invention,representing the transmitted symbols and received symbols on the kth subcarrier, respectively, 0.ltoreq.k<N；/>Representing a time delay tau at the kth subcarrier l The frequency offset is f l Frequency domain sample values of a window function, i.ep>0, indicated in the calculation->Time-to-window function frequency domain response +.>A cut-off range of the side lobe; Δf represents a subcarrier spacing satisfying tΔf=1, and T represents an OFDM symbol duration; />Representing independent co-distributed additive gaussian noise.
9. The fvd-based high speed moving scene windowing OFDM communication system as claimed in claim 8, wherein the input-output relationship of the windowing OFDM communication system is abbreviated as a matrix form:
in the method, in the process of the invention,representing a frequency domain equivalent channel matrix with a bandwidth q, q=2p+1; />
In the frequency-variable Viterbi detection module, q is set to be less than or equal to 5 when a frequency-variable Viterbi detection algorithm is adopted for symbol detection.
10. A fvd-based high speed mobile scene windowing OFDM communication system according to any of claims 8-9, wherein:
definition parameter Ω=pΔf-f D In the windowing module, the window function u (t) is an integral equation
One of all solutions that maximizes λ;
wherein f D Indicating the maximum doppler shift.
CN202311245802.4A 2023-09-25 2023-09-25 fVD-based high-speed mobile scene windowing OFDM communication method Pending CN117319159A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311245802.4A CN117319159A (en) 2023-09-25 2023-09-25 fVD-based high-speed mobile scene windowing OFDM communication method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311245802.4A CN117319159A (en) 2023-09-25 2023-09-25 fVD-based high-speed mobile scene windowing OFDM communication method

Publications (1)

Publication Number Publication Date
CN117319159A true CN117319159A (en) 2023-12-29

Family

ID=89287771

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311245802.4A Pending CN117319159A (en) 2023-09-25 2023-09-25 fVD-based high-speed mobile scene windowing OFDM communication method

Country Status (1)

Country Link
CN (1) CN117319159A (en)

Similar Documents

Publication Publication Date Title
Muquet et al. Subspace-based blind and semi-blind channel estimation for OFDM systems
WO2009089753A1 (en) A method and device for peak-to-average ratio suppression in multi-carrier orthogonal frequency division multiplexing system
CN109462443B (en) 5G multi-carrier underwater acoustic communication method
CN113452641B (en) FBMC channel estimation method, system, computer equipment and terminal
Sharma et al. On BER assessment of conventional-and wavelet-OFDM over AWGN channel
An et al. WR-OFDM system and OOB spectrum comparison
KR101145002B1 (en) Blind estimation method and apparatus for ofdm frequency offset
KR102132253B1 (en) Orthogonal frequency division multiplexing system using windowed Cyclic Prefix and Cyclic Postfix
CN112039815B (en) Interference elimination method applied to filter bank multi-carrier system and application thereof
CN108880777B (en) Channel detection reference signal sending and receiving method suitable for UFMC waveform
CN107566311B (en) Transmission method based on resource block filtering RB F-OFDM system
Yu et al. Reducing out-of-band radiation of OFDM-based cognitive radios
Cruz-Roldán et al. Intersymbol and intercarrier interference in OFDM systems: Unified formulation and analysis
CN117319159A (en) fVD-based high-speed mobile scene windowing OFDM communication method
Peng et al. Discrete Fourier transform‐based block transmission for multi‐carrier faster‐than‐Nyquist signalling
Sheu et al. A low complexity ICI cancellation scheme with multi-step windowing and modified SIC for high-mobility OFDM systems
Al Soufy An efficient transmission of image over SC-FDMA system in the presence of CFO
Jose et al. Peak to average power ratio reduction and inter symbol interference cancellation of FBMC-OQAM signals
CN108462665B (en) Construction method for UFMC sending signal waveform
Shen et al. Narrowband interference suppression in underwater acoustic OFDM system
CN113411281B (en) F-OFDM wireless transmission method based on parallel interference elimination
Indiarto et al. Analysis of Equalizer Performance against Bit Error Rate in Filter Bank Multicarrier System with AWGN and Multipath Channel
Chen et al. Symbol cyclic reconstruction scheme for UFMC‐based systems
Rahman et al. The study of OFDM ICI cancellation schemes in 2.4 GHz frequency band using software defined radio
KR101492641B1 (en) Method for estimating and compensating channel and receiver using the same

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