CN117978286B - Preprocessing ABLO-OFDM method, device, medium and equipment integrating high-precision dimming - Google Patents
Preprocessing ABLO-OFDM method, device, medium and equipment integrating high-precision dimming Download PDFInfo
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Abstract
The invention discloses a pre-processing ABLO-OFDM method, a device, a medium and equipment for fusing high-precision dimming, wherein the method comprises the following steps: acquiring an original ABLO-OFDM frequency domain signal and a PWM signal; processing and adjusting the PWM signals to obtain two-stage PWM dimming signals; preprocessing an original frequency domain signal, and performing inverse discrete Fourier transform to obtain a transformed signal; superposing the transformed signals with self-adaptive bias to obtain superposed signals; carrying out reverse processing on the superimposed signals to obtain reverse signals; and combining the inverted signal with the two-stage PWM dimming signal and outputting the combined signal to an optical channel. On the premise of ensuring that the transmission rate is not reduced, the PWM signal is identical to the number of the ABLO-OFDM symbols occupied, the subcarrier scale adjustment is carried out on the dimming precision, the dimming fineness is improved, the frequency spectrum resource is fully utilized, the complexity of a receiver is reduced, and the receiver has better transmission performance.
Description
Technical Field
The invention relates to a pre-processing ABLO-OFDM method, device, medium and equipment integrating high-precision dimming, belonging to the technical field of visible light communication.
Background
VLC (Visible Light Communications, visible light communication) is considered as a key candidate of 6G, and has the characteristics of high transmission rate, wide frequency band and the like. The combination of the visible light communication and the solid-state lighting technology is tight, and the improvement of the dimming fineness is a direction to be developed under the condition of ensuring the constant transmission rate.
In the field of visible light communication, low cost intensity modulation/direct detection schemes are widely used. This scheme requires that the signal appear in positive form.
The main idea of the OFDM (Orthogonal Frequency Division Multiplexing ) technology is to divide a channel in a frequency domain into a plurality of orthogonal subchannels, which has the capability of high frequency band utilization and interference resistance. To meet the intensity modulation/direct detection scheme LACO-OFDM (LAYERED ASYMMETRICALLY CLIPPED Optical-Orthogonal Frequency Division Multiplexing, layered asymmetric tailored Optical orthogonal frequency division multiplexing technique) is widely used. This scheme has high spectral efficiency but the receiver is more complex.
ABLO-OFDM (Layered Optical-Orthogonal Frequency Division Multiplexing WITH ADAPTIVE Bias adaptive offset layered optical orthogonal frequency division multiplexing) is a LACO-OFDM based technique, and uses specific carriers without information to add adaptive offset to the subcarriers, so that signals appear in positive form. The sub-carrier of the self-adaptive bias is orthogonal with the sub-carrier for transmitting information, and the transmission of the information is not affected. ABLO-OFDM has the characteristics of high spectrum efficiency and low complexity of a receiver.
PWM (Pulse Width Modulation ) is an analog control scheme that adjusts the average voltage by adjusting the pulse width. The method is widely applied to dimming systems and has the characteristics of simplicity in implementation and high precision.
In order to integrate the PWM-based dimming procedure well into ABLO-OFDM transmission, the period of the PWM signal is set to an integer multiple of the single ABLO-OFDM symbol duration, which means that the PWM signal remains constant for a single ABLO-OFDM symbol duration T 0 seconds, the PWM signal only affecting the 0 th subcarrier, without contaminating the transmitted information data. However, this method results in the PWM signal period being limited to ABLO-OFDM symbol period, and in practical applications, the dimming fineness cannot well meet the user demand.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a pre-processing ABLO-OFDM method, a device, a medium and equipment for fusing high-precision dimming, wherein the number of PWM signals is the same as that of occupied ABLO-OFDM symbols on the premise of ensuring that the transmission rate is not reduced, the dimming precision is subjected to subcarrier scale adjustment, and the dimming fineness is improved.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
in a first aspect, the present invention provides a preprocessing ABLO-OFDM method incorporating high-precision dimming, including:
Obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
processing the PWM signal according to dimming control to generate a two-stage PWM signal; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
for the original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal/>Performing reverse processing to obtain a reverse signal/>；
The signal after the reverse direction is processedAnd combining the two-stage PWM dimming signals and outputting the two-stage PWM dimming signals to an optical channel.
With reference to the first aspect, optionally, the pair of original ABLO-OFDM frequency domain signalsSequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>Comprising:
according to the dimming control, the original ABLO-OFDM frequency domain signal Preprocessing to obtain the frequency domain signal/>, of ABLO-OFDM after preprocessingRepresented by the following formula:
（1）
In the formula (1), the components are as follows, Is a frequency domain signal of ABLO-OFDM after pretreatment,/>Is the original ABLO-OFDM frequency domain signal,/>Is a pre-processed signal, wherein k=0, …, N-1, N is the number of subcarriers; /(I)Representing a cyclic convolution operation;
for the frequency domain signal of ABLO-OFDM after pretreatment Performing inverse discrete Fourier transform to obtain transformed signal/>Represented by the following formula:
（2）
in the formula (2), the amino acid sequence of the compound, N=0, …, N-1, N is the number of subcarriers; e is a natural constant, j is an imaginary number of complex units.
With reference to the first aspect, optionally, the step of combining the signalsSuperposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive biasRepresented by the following formula:
（3）
In the formula (3), the amino acid sequence of the compound, For superimposing the adaptively biased signal,/>N=0, …, N-1, N is the number of subcarriers; /(I)For adaptive biasing, this is represented by:
（4）
In the formula (4), max is a maximum symbol, q is an integer, L is the number of layers of ABLO-OFDM, and N is the number of subcarriers.
With reference to the first aspect, optionally, the step of combining the signalsPerforming reverse processing to obtain a reverse signal/>Wherein the inverse processing is to/>, the signalMultiplied by polarity control signal/>Represented by the following formula:
（5）
in the formula (5), the amino acid sequence of the compound, Is a signal after the reverse,/>For superimposing the adaptively biased signals, where n=0, …, N-1, N is the number of subcarriers; /(I)The polarity control signal is taken as a value according to the state of the two-stage PWM dimming signal, and is expressed by the following formula:
（6）
In the formula (6), the amino acid sequence of the compound, For a two-stage dimming PWM signal, when the LED is operating at the maximum value of the linear interval/>When the two-stage PWM dimming signal is in an on state,/>The value is-1, when the LED works at the minimum value/>, of the linear intervalWhen the two-stage PWM dimming signal is in the off state,/>The value is 1.
With reference to the first aspect, optionally, the polarity control signalIs used for carrying out Fourier transformation on the original ABLO-OFDM frequency domain signal/>Pretreatment signal/>, pretreated。
With reference to the first aspect, optionally, the PWM signal is processed according to a dimming control, and a two-stage PWM signal is generated, where the two-stage PWM signal is represented by the following formula:
（7）
In the formula (7), the amino acid sequence of the compound, Is a two-stage PWM signal,/>For the maximum value of the linear interval of LED operation,/>The minimum value of the linear interval for the LED to work; representation of
Wherein,
When t is in the range ofWhen the PWM signal takes on a value of/>，/>Representing ABLO-OFDM symbol number occupied by PWM signal in on state,/>A symbol period of a single ABLO-OFDM;
When t is in the range of When the PWM signal takes on a value of/>；/>Representing the number of sampling points occupied by the two-stage PWM signal in the on state,/>Is the sampling period, denoted/>N is the number of subcarriers, L is the number of layers of ABLO-OFDM, L is an integer,/>；
When the value of t is in other range, the value of the PWM signal is。
With reference to the first aspect, optionally, the number of ABLO-OFDM symbols occupied by the PWM signal in the on state is adjustedThe value of (2) and the number of sampling points occupied by the two-stage PWM signal in the on state/>And (3) adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals.
In a second aspect, the present invention provides a preprocessing ABLO-OFDM device incorporating high-precision dimming, comprising:
the acquisition module is used for: for obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
a first processing module: the PWM signal is processed according to dimming control, and a two-stage PWM signal is generated; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
and a second processing module: for applying to said original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal/>Performing reverse processing to obtain a reverse signal/>；
And (3) combining an output module: for reversing the signalAnd combining the two-stage PWM dimming signals and outputting the two-stage PWM dimming signals to an optical channel.
In a third aspect, the present invention provides a computer readable storage medium having stored thereon a computer program/instruction which, when executed by a processor, implements the steps of the preprocessing ABLO-OFDM method of the first aspect of fused high-precision dimming.
In a fourth aspect, the present invention provides a computer device comprising:
A memory for storing computer programs/instructions;
A processor for executing the computer program/instructions to implement the steps of the preprocessing ABLO-OFDM method of the first aspect that fuses high-precision dimming.
Compared with the prior art, the pretreatment ABLO-OFDM method, device, medium and equipment for fusing high-precision dimming provided by the embodiment of the invention have the beneficial effects that:
The invention sequentially carries out pretreatment and inverse discrete Fourier transform on the original frequency domain signal to obtain a transformed signal; superposing the transformed signals with self-adaptive bias to obtain superposed signals; carrying out reverse processing on the superimposed signals to obtain reverse signals; the pretreatment and the reverse treatment provided by the invention can still transmit information in the pulse phase of the PWM signal, the complexity of the receiver is not increased, and the receiving can be realized by using a standard OFDM receiver;
The invention processes the PWM signal to generate two-stage PWM signal; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals; in the traditional dimming method, the dimming step length is required to be adjusted by integer times of the number of single OFDM symbols, the dimming precision is limited by the number of ABLO-OFDM symbols occupied by PWM signals, and on the premise of ensuring that the transmission rate is not reduced, the invention realizes that the number of PWM signals is the same as the number of occupied ABLO-OFDM symbols, and the dimming precision is subjected to finer subcarrier scale adjustment, thereby improving the dimming precision;
The invention combines the signal after reverse and two-stage PWM signal to output to the optical channel; compared with other existing dimming technologies, the two-stage PWM signal falls on the subcarrier which does not bear information, and the transmission of the information is not affected, so that the dependence of ABLO-OFDM signal detection on the dimming level of the two-stage PWM is avoided; the spectrum resource is fully utilized, the complexity of the receiver is reduced, and the transmission performance is better.
Drawings
Fig. 1 is a schematic diagram of a preprocessing ABLO-OFDM method for fusing high-precision dimming according to an embodiment of the present invention;
Fig. 2 is a schematic diagram of two-stage PWM signals in a preprocessing ABLO-OFDM method incorporating high-precision dimming according to a first embodiment of the present invention;
Fig. 3 is a graph of dimming resolution under different symbol numbers for a preprocessing ABLO-OFDM method and a tunable ABLO-OFDM method that incorporate high-precision dimming according to an embodiment of the present invention.
Detailed Description
The following detailed description of the present invention is made with reference to the accompanying drawings and specific embodiments, and it is to be understood that the specific features of the embodiments and the embodiments of the present invention are detailed description of the technical solutions of the present invention, and not limited to the technical solutions of the present invention, and that the embodiments and the technical features of the embodiments of the present invention may be combined with each other without conflict.
Embodiment one:
As shown in fig. 1, an embodiment of the present invention provides a preprocessing ABLO-OFDM method for fusing high-precision dimming, including:
Obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
Processing the PWM signal according to dimming control to generate a two-stage PWM signal; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
for the original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal/>Performing reverse processing to obtain a reverse signal/>；
The signal after the reverse direction is processedAnd combining the two-stage PWM signals and outputting to an optical channel.
The method comprises the following specific steps:
Step 1: obtaining original ABLO-OFDM frequency domain signal And a PWM signal.
Step 2: processing the PWM signal according to dimming control to generate a two-stage PWM signal; and regulating the two-stage PWM signals to obtain two-stage PWM dimming signals.
A two-stage PWM signal represented by:
（1）
In the formula (1), the components are as follows, Is a two-stage PWM signal,/>For the maximum value of the linear interval of LED operation,/>The minimum value of the linear interval for the LED to work;
Wherein,
When t is in the range ofWhen the PWM signal takes on a value of/>，/>Representing ABLO-OFDM symbol number occupied by PWM signal in on state,/>A symbol period of a single ABLO-OFDM;
When t is in the range of When the PWM signal takes on a value of/>；/>Representing the number of sampling points occupied by the two-stage PWM signal in the on state,/>Is the sampling period, denoted/>N is the number of subcarriers, L is the number of layers of ABLO-OFDM, L is an integer,/>；
When the value of t is in other range, the value of the PWM signal is。
As shown in fig. 2, M 1 is the number of ABLO-OFDM symbols occupied by the PWM signal,The number of ABLO-OFDM symbols occupied by the PWM signal in the on state is shown in/>And/>Further modulation is performed between +1 ABLO-OFDM symbols. When/>At this time, the PWM signal is set to a high level, thereby being processed as a two-stage PWM signal, so that the dimming fineness is not limited to the symbol period of ABLO-OFDM.
By adjusting the number of ABLO-OFDM symbols occupied by PWM signals in an on stateThe value of (2) and the number of sampling points occupied by the two-stage PWM signal in the on state/>And (3) adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals, and adjusting the dimming level.
In the traditional dimming method, the dimming step length needs to be adjusted by integer times of the number of single OFDM symbols, and the dimming precision is limited by the number of ABLO-OFDM symbols occupied by the PWM signal. On the premise of ensuring that the transmission rate is not reduced, the embodiment realizes that the PWM signal is identical to the number of the ABLO-OFDM symbols occupied, and the dimming precision is subjected to finer subcarrier scale adjustment, so that the dimming fineness is improved.
Step 3: according to the dimming control, the original ABLO-OFDM frequency domain signalPreprocessing to obtain the frequency domain signal/>, of ABLO-OFDM after preprocessing. Represented by the formula:
（2）
in the formula (2), the amino acid sequence of the compound, Is a frequency domain signal of ABLO-OFDM after pretreatment,/>Is the original ABLO-OFDM frequency domain signal,/>Is a pre-processed signal, wherein k=0, …, N-1, N is the number of subcarriers; /(I)Representing a cyclic convolution operation.
Step 4: for the frequency domain signal of ABLO-OFDM after pretreatmentPerforming inverse discrete Fourier transform to obtain transformed signal/>. Represented by the formula:
（3）
In the formula (3), the amino acid sequence of the compound, N=0, …, N-1, N is the number of subcarriers; e is a natural constant, j is an imaginary number of complex units.
Step 5: by converting the signals after conversionSuperposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias. Represented by the formula:
（4）
In the formula (4), the amino acid sequence of the compound, For superimposing the adaptively biased signal,/>N=0, …, N-1, N is the number of subcarriers; /(I)For adaptive biasing, this is represented by:
（5）
In the formula (5), max is a maximum symbol, q is an integer, L is the number of layers of ABLO-OFDM, and N is the number of subcarriers.
Step 6: signals to be superimposed with adaptive biasPerforming reverse processing to obtain a reverse signal/>。
Reverse processing to superimpose adaptively biased signalsMultiplied by polarity control signal/>Represented by the following formula:
（6）
In the formula (6), the amino acid sequence of the compound, Is a signal after the reverse,/>For superimposing the adaptively biased signals, where n=0, …, N-1, N is the number of subcarriers.
The polarity control signal is taken as a value according to the state of the two-stage PWM dimming signal, and is expressed by the following formula:
（7）
In the formula (7), the amino acid sequence of the compound, For a two-stage PWM dimming signal, when the LED is operated at the maximum value of the linear interval/>When the two-stage PWM dimming signal is in an on state,/>The value is-1, when the LED works at the minimum value/>, of the linear intervalWhen the two-stage PWM dimming signal is in the off state,/>The value is 1.
The polarity control signalAfter Fourier transformation, the frequency domain signal is used for carrying out the frequency domain signal/>, which is used for the original ABLO-OFDMPretreatment signal/>, pretreated(Pretreatment Signal in step 3/>)）。
The preprocessing and the reverse processing provided by the embodiment enable information to be still transferred in the pulse phase of the PWM signal, the complexity of the receiver is not increased, and the receiving can be realized by using a standard OFDM receiver.
Step 7: will reverse the signalAnd the light signal is combined with the two-stage PWM dimming signal and output to an optical channel.
Further, as shown in fig. 1, after receiving the combined signal, the light-emitting secondary light of the receiver is sequentially subjected to analog-to-digital conversion, serial-to-parallel conversion and fourier transformation, and then is input to a demodulator, and the signal is converted by the demodulator and then is input for use.
As shown in FIG. 3, compared with the adjustable light ABLO-OFDM method, the preprocessing ABLO-OFDM method for fusing high-precision light dimming provided by the application has higher light dimming fineness and higher resolution.
Specifically, when the number of symbols is l=3, the preprocessing ABLO-OFDM method for fusing high-precision dimming provided by the application has higher dimming fineness and higher resolution compared with the tunable ABLO-OFDM method. When the number of symbols is L=4, the preprocessing ABLO-OFDM method integrating high-precision dimming is adopted, and compared with the adjustable ABLO-OFDM method, the dimming fineness is higher, and the resolution is higher.
Compared with other existing dimming technologies, the two-stage PWM signals fall on subcarriers which do not bear information, and information transmission is not affected, so that dependency of ABLO-OFDM signal detection on dimming level of the two-stage PWM is avoided; the spectrum resource is fully utilized, the complexity of the receiver is reduced, and the transmission performance is better.
Embodiment two:
the embodiment of the invention provides a preprocessing ABLO-OFDM device integrating high-precision dimming based on the first embodiment, which comprises the following steps:
the acquisition module is used for: for obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
a first processing module: the PWM signal is processed according to dimming control, and a two-stage PWM signal is generated; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
and a second processing module: for applying to said original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal/>Performing reverse processing to obtain a reverse signal/>；
And (3) combining an output module: for reversing the signalAnd combining the two-stage PWM dimming signals and outputting the two-stage PWM dimming signals to an optical channel.
Embodiment III:
The embodiment of the invention provides a computer readable storage medium, on which a computer program/instruction is stored, which when executed by a processor, implements the steps of the preprocessing ABLO-OFDM method described in embodiment one, which fuses high-precision dimming.
Embodiment four:
An embodiment of the present invention provides a computer apparatus including:
A memory for storing computer programs/instructions;
and a processor for executing the computer program/instructions to implement the steps of the preprocessing ABLO-OFDM method described in embodiment one that fuses high-precision dimming.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are all within the protection of the present invention.
Claims (8)
1. The preprocessing ABLO-OFDM method integrating high-precision dimming is characterized by comprising the following steps of:
Obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
processing the PWM signal according to dimming control to generate a two-stage PWM signal; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
the PWM signal is processed according to dimming control, and a two-stage PWM signal is generated, wherein the two-stage PWM signal is represented by the following formula:
（7）
In the formula (7), the amino acid sequence of the compound, Is a two-stage PWM signal,/>For the maximum value of the linear interval of LED operation,/>The minimum value of the linear interval for the LED to work;
Wherein,
When t is in the range ofWhen the PWM signal takes on a value of/>，/>Representing ABLO-OFDM symbol number occupied by PWM signal in on state,/>A symbol period of a single ABLO-OFDM;
When t is in the range of When the PWM signal takes on a value of/>；/>Representing the number of sampling points occupied by the two-stage PWM signal in the on state,/>For sampling period, expressed asN is the number of subcarriers, L is the number of layers of ABLO-OFDM, L is an integer,/>；
When the value of t is in other range, the value of the PWM signal is；
Wherein, by adjusting the number of ABLO-OFDM symbols occupied by PWM signal in on stateThe value of (2) and the number of sampling points occupied by the two-stage PWM signal in the on state/>The two-stage PWM signals are regulated to obtain two-stage PWM dimming signals;
for the original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal is processedPerforming reverse processing to obtain a reverse signal/>；
The signal after the reverse direction is processedAnd combining the two-stage PWM dimming signals and outputting the two-stage PWM dimming signals to an optical channel.
2. The method of claim 1, wherein the pre-processing ABLO-OFDM of the original ABLO-OFDM frequency domain signalSequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>Comprising:
according to the dimming control, the original ABLO-OFDM frequency domain signal Preprocessing to obtain the frequency domain signal/>, of ABLO-OFDM after preprocessingRepresented by the following formula:
（1）
In the formula (1), the components are as follows, Is a frequency domain signal of ABLO-OFDM after pretreatment,/>Is the original ABLO-OFDM frequency domain signal,/>Is a pre-processed signal, wherein k=0, …, N-1, N is the number of subcarriers; /(I)Representing a cyclic convolution operation;
for the frequency domain signal of ABLO-OFDM after pretreatment Performing inverse discrete Fourier transform to obtain transformed signal/>Represented by the following formula:
（2）
in the formula (2), the amino acid sequence of the compound, N=0, …, N-1, N is the number of subcarriers; e is a natural constant, j is an imaginary number of complex units.
3. The method of pre-processing ABLO-OFDM with integrated high precision dimming according to claim 1, wherein the step of combining the signalsSuperposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive biasRepresented by the following formula:
（3）
In the formula (3), the amino acid sequence of the compound, For superimposing the adaptively biased signal,/>N=0, …, N-1, N is the number of subcarriers; /(I)For adaptive biasing, this is represented by:
（4）
In the formula (4), max is a maximum symbol, q is an integer, L is the number of layers of ABLO-OFDM, and N is the number of subcarriers.
4. The method of pre-processing ABLO-OFDM with integrated high precision dimming according to claim 1, wherein the step of combining the signalsPerforming reverse processing to obtain a reverse signal/>Wherein the inverse processing is to/>, the signalMultiplied by polarity control signal/>Represented by the following formula:
（5）
in the formula (5), the amino acid sequence of the compound, Is a signal after the reverse,/>For superimposing the adaptively biased signals, where n=0, …, N-1, N is the number of subcarriers; /(I)The polarity control signal is taken as a value according to the state of the two-stage PWM dimming signal, and is expressed by the following formula:
（6）
In the formula (6), the amino acid sequence of the compound, For a two-stage PWM dimming signal, when the LED is operated at the maximum value of the linear interval/>When the two-stage PWM dimming signal is in an on state,/>The value is-1, when the LED works at the minimum value/>, of the linear intervalWhen the two-stage PWM dimming signal is in the off state,/>The value is 1.
5. The method of pre-processing ABLO-OFDM with integrated high precision dimming of claim 4, wherein the polarity control signalIs used for carrying out Fourier transformation on the original ABLO-OFDM frequency domain signal/>Pretreatment signal/>, pretreated。
6. A preprocessing ABLO-OFDM device incorporating high-precision dimming, comprising:
the acquisition module is used for: for obtaining original ABLO-OFDM frequency domain signal And a PWM signal;
a first processing module: the PWM signal is processed according to dimming control, and a two-stage PWM signal is generated; adjusting the two-stage PWM signals to obtain two-stage PWM dimming signals;
the PWM signal is processed according to dimming control, and a two-stage PWM signal is generated, wherein the two-stage PWM signal is represented by the following formula:
（7）
In the formula (7), the amino acid sequence of the compound, Is a two-stage PWM signal,/>For the maximum value of the linear interval of LED operation,/>The minimum value of the linear interval for the LED to work;
Wherein,
When t is in the range ofWhen the PWM signal takes on a value of/>，/>Representing ABLO-OFDM symbol number occupied by PWM signal in on state,/>A symbol period of a single ABLO-OFDM;
When t is in the range of When the PWM signal takes on a value of/>；/>Representing the number of sampling points occupied by the two-stage PWM signal in the on state,/>For sampling period, expressed asN is the number of subcarriers, L is the number of layers of ABLO-OFDM, L is an integer,/>；
When the value of t is in other range, the value of the PWM signal is；
Wherein, by adjusting the number of ABLO-OFDM symbols occupied by PWM signal in on stateThe value of (2) and the number of sampling points occupied by the two-stage PWM signal in the on state/>The two-stage PWM signals are regulated to obtain two-stage PWM dimming signals;
and a second processing module: for applying to said original ABLO-OFDM frequency domain signal Sequentially preprocessing and inverse discrete Fourier transforming to obtain transformed signal/>; The signal/>Superposing the self-adaptive bias to obtain a signal/>, of the superposition self-adaptive bias; The signal/>Performing reverse processing to obtain a reverse signal/>；
And (3) combining an output module: for reversing the signalAnd combining the two-stage PWM dimming signals and outputting the two-stage PWM dimming signals to an optical channel.
7. A computer readable storage medium having stored thereon a computer program/instructions, which when executed by a processor, performs the steps of the pre-processing ABLO-OFDM method of fused high-precision dimming as claimed in any one of claims 1-5.
8. A computer device, comprising:
A memory for storing computer programs/instructions;
a processor for executing the computer program/instructions to implement the steps of the pre-processing ABLO-OFDM method of fused high-precision dimming of any one of claims 1-5.
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