CN105282068A - Pre-emphasis and equalization method based on least square method in wireless light communication - Google Patents
Pre-emphasis and equalization method based on least square method in wireless light communication Download PDFInfo
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Abstract
The invention provides a pre-emphasis and equalization method based on the least square method in a wireless light communication, and belongs to the wireless light communication field. The method includes the steps of: removing resistors and capacitors in n branches in a pre-emphasis circuit, keeping inputting amplitudes of sinusoidal signals of the pre-emphasis circuit, changing frequencies of the input sinusoidal signals, testing the output voltage amplitudes under different frequency points, and obtaining an attenuation-frequency curve responsive to E/O/E without using the pre-emphasis circuit; respectively carrying out normalization processing on the attenuation-frequency curve and a gain-frequency curve of the pre-emphasis network, carrying out fitting on the normalized gain-frequency curve and the normalized attenuation-frequency curve by using the least square method, and calculating the values of the resistors and the capacitors in the n branches. According to the invention, the problem that the selection of the present resistors and capacitors is blind and inefficient, the optimal resistance and capacitance can be effectively and quickly obtained, and the obtained pre-emphasis equalization circuit has a wider bandwidth and is flatter in the passband.
Description
Technical field
The present invention relates to wireless light communication field, refer more particularly to the technology in visible light communication field, specifically a kind of preemphasis based on least square method and equalization methods.
Background technology
Visible light communication (VisibleLightCommunications, VLC) technology is using visible LED as light source, using photodetector as signal receiving end, take air as channel, will a kind of wireless light communication technology of the enterprising Serial Communication of visible ray that signal madulation sends at LED be sent.
Along with developing rapidly of solid state lighting, LED uses more and more extensive as lighting source.As compared to the light source such as traditional incandescent lamp and fluorescent lamp, the longer service life of LED and have much wide modulation bandwidth, can carry out switching over higher frequency, this makes to carry out high-speed communication using LED as light source becomes possibility.Because modulating frequency is very high, human eye is not aware of the flicker of light.Usually, visible light communication as second function of LED, can complete communication while illumination.
Along with deepening continuously of studying for high-speed communication, LED bandwidth becomes the bottleneck of high-speed communication, and common illumination LED only has very little three dB bandwidth, and this becomes the bottleneck of high-speed communication.
In order to address this problem, a lot of schemes is suggested.In these schemes, based on preemphasis and (or) post-equalization circuit (the reference paper 1:HighBandwidthVisibleLightCommunicationsBasedonaPost-Eq ualizationCircuit of resistance-capacitance (R-C); HongleiLi, XiongbinChen etc.; PHOTONICSTECHNOLOGYLETTERS:JANUARY15,2014, VOL.26, NO.2,119-122) have cost-efficiently feature, wherein resistance and choosing of electric capacity play vital effect for portfolio effect.But select optimum resistance capacitance combination to be very difficult, the existing constantly replacing components and parts that can only lean on carry out experiment measuring to find optimum combination.If the inappropriate words of combination selected, namely allow to spread bandwidth, the Flatness of frequency response of E/O/E also can be made to be deteriorated.And uneven E/O/E response can cause distorted signals and limit maximum character rate.Wherein E/O/E is the abbreviation of electricity-light-electricity, and in optical communication system, the signal of telecommunication is modulated on visible ray and transmits, and carries out opto-electronic conversion, become the signal of telecommunication at receiving terminal, completes the process of once electricity-light-electricity like this.
Summary of the invention
For existing visible ray preemphasis and (or) post-equalization technology Problems existing: when selecting optimum resistance electric capacity, can only by constantly changing components and parts, the method measured by experiment finds optimum combination, and this Measures compare blindly, is wasted time and energy; Although communication bandwidth is expanded, its passband is usually uneven, and communication performance is limited.The invention provides a kind of preemphasis based on least square method and equalization methods.
Preemphasis based on least square method provided by the invention and equalization methods, be applied to the LED drive circuit of the preemphasis circuit realized based on resistance and electric capacity, wherein preemphasis circuit is n rank, comprise n branch road in parallel, each branch road is the series circuit of a resistance and an electric capacity, and n is positive integer; The input voltage of preemphasis circuit is designated as V
in; The object of the invention is the value obtaining resistance and electric capacity in n branch road, performing step is as follows:
Step 1, removes the resistance in the branch road of n in preemphasis circuit and electric capacity, measures the attenuation versus frequency curve not using the E/O/E of preemphasis circuit to respond.
Step 1.1, arranges amplitude and the frequency of sine voltage signal, and the initial value of frequency is 0Hz;
Step 1.2, the sine voltage signal of current setting is inputted to the preemphasis circuit removing resistance and electric capacity, the photoelectric detector of the light receiving end that LED sends is converted to current signal, is then converted to voltage signal by preamplifier, records the amplitude of the output voltage signal obtained;
Step 1.3, judges whether to obtain the data on m Frequency point, and if not, the amplitude maintaining the sine voltage signal of input is constant, with the frequency of the frequency interval set as step value change sine voltage signal, then continues step 1.2; If so, calculate input voltage on each Frequency point and, to the decay of output voltage, obtain an attenuation versus frequency curve.Wherein, m is positive integer, decays to represent with dB.
Step 1.4, setting decay minimum frequency point decays to 0, and attenuation versus frequency curve step 1.3 obtained, along decay direction translation, obtains a normalized attenuation versus frequency curve.
Step 2, makes the gain-frequency curve of preemphasis network and the matching of normalized attenuation versus frequency curve phase by least square method, asks for the value of resistance and electric capacity in n branch road.
Step 2.1, analyze the LED drive circuit of the preemphasis circuit realized based on resistance and electric capacity, obtain the gain versus frequency function of the preemphasis circuit realized based on resistance and electric capacity, the gain-frequency curve of correspondence is normalized, gain on setting gain minimum frequency point is 0, by gain-frequency curve along gain direction translation, obtain a normalized gain-frequency curve;
Step 2.2, makes normalized gain-frequency curve and normalized attenuation versus frequency curve carry out matching by least square method, obtains the value of optimized resistance and electric capacity.
Wherein, the target function value S of least square method is expressed as:
Ask for n the resistance R making S minimum
1..., R
nand n electric capacity C
1..., C
n, f
irepresent i-th frequency, i=1,2 ..., m; G
nf
ifunction, represent the gain-frequency curve of normalized preemphasis circuit; A
nrepresent the normalized attenuation versus frequency curve that step 1 obtains.
Advantage of the present invention and good effect are: of the present inventionly solve when designing preemphasis and/or post-equalization circuit, and resistance capacitance selects the problem of blindly poor efficiency.By using least square method, carry out the normalized attenuation versus frequency curve of matching with normalized gain-frequency curve, thus obtain optimum resistance capacitance value.Compare tradition obtains resistance capacitance value method by continuous test experiments, speed is faster, and efficiency is higher.Compare conventional method, it is simultaneously more smooth in passband that the preemphasis equalizing circuit obtained has wider bandwidth.
Accompanying drawing explanation
Fig. 1 is the LED drive circuit applied of the present invention and second order preemphasis circuit schematic diagram;
Fig. 2 is the test frame schematic diagram that the embodiment of the present invention measures E/O/E response;
Fig. 3 is the attenuation versus frequency curve synoptic diagram measured in the embodiment of the present invention;
Fig. 4 is that the embodiment of the present invention is by the schematic diagram of gain-frequency curve matching attenuation versus frequency curve;
Fig. 5 is the amplitude-frequency characteristic figure of visible light communication system after embodiment of the present invention use preemphasis circuit;
Fig. 6 is the transmission eye pattern obtained after the embodiment of the present invention uses preemphasis circuit; A () is the eye pattern under 100Mbps pseudorandom pattern test transmission; B () is the eye pattern under 200Mbps pseudorandom pattern test transmission; C () is the eye pattern under 300Mbps pseudorandom pattern test transmission;
Fig. 7 is the schematic diagram that the embodiment of the present invention uses preemphasis and equalizing circuit simultaneously;
Fig. 8 is that the bandwidth that the embodiment of the present invention uses Fig. 7 circuit to obtain is expanded rear obtained amplitude-frequency characteristic figure;
Fig. 9 is the embodiment of the present invention error rate that uses Fig. 7 circuit to obtain and eye pattern example.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described in further detail.
The visible ray that the efficient cost that the object of the invention is to find is low increases the weight of equalization methods, by visible light communication bandwidth expansion.While expansion visible light communication bandwidth, ensure the evenness in spectral passband, better transmission performance is provided.Least square method is applied to preemphasis and (or) post-equalization circuit design by the present invention, solves optimum capacitance and resistance value.
LED drive circuit below in conjunction with a preemphasis circuit illustrates the preemphasis based on least square method of the present invention and equalization methods, comprises step 1 ~ step 2.
As shown in Figure 1, right side is a LED driver.As the driver of function admirable, its Output optical power and input voltage should meet linear relationship in wider scope.And LED is as a kind of nonlinear device, its forward current along with forward voltage exponentially type increase, the linear relationship that its luminous power exported can only keep roughly with forward current.In the embodiment of the present invention, the LED drive circuit of the band preemphasis circuit used comprises the operational amplifier A of two cascades
1and A
2, first operational amplifier A
1be used for realizing preemphasis function, second operational amplifier A
2be used for driving LED.Second operational amplifier A
2be operated in linear zone, the forward current of LED can be expressed as:
Wherein i
ledfor the forward current of LED, V
in1the input voltage of LED driver, R
sit is inspection leakage resistance.
Preemphasis circuit of the present invention, mainly by operational amplifier A
1the second order preemphasis circuit formed, also can be designed to more than second order as required.As is illustrated in the left side of fig. 1, second order preemphasis circuit comprises operational amplifier, resistance R
1, R
2, R
fand R
g, electric capacity C
1and C
2, R
f, R
gand A
1form common non-inverting amplifier, resistance R
fand R
gdetermine DC current gain, with resistance R
gbe parallel with n branch road, each branch road is connected a resistance and an electric capacity.With resistance R
gresistance in parallel and capacitive branch number n represent the exponent number of preemphasis circuit, and n is positive integer.In Fig. 1, resistance R
1with electric capacity C
1series connection, resistance R
2with electric capacity C
2series connection, two series circuits again with R
gin parallel.The resistance of series connection and electric capacity and resistance R
gimpedance Z is obtained after parallel connection
gamplitude reduce with frequency, so at V
inradio-frequency component can obtain higher gain, V
inbe first operational amplifier A
1input voltage.
The object of the embodiment of the present invention determines resistance R
1, R
2with electric capacity C
1, C
2.
Step 1, removes R
1, R
2, C
1and C
2, attenuation versus frequency curve in the E/O/E response of measuring circuit.
The object of this step is that namely the embodiment of the present invention is for removing R after the resistance in the branch road of n in preemphasis circuit and electric capacity being removed
1, R
2, C
1and C
2when, the attenuation versus frequency curve in measuring system E/O/E response.
This test can complete by the instrument such as function generator and oscilloscope, also can complete with vector network analyzer, and this method is to illustrate this test process based on the method for measurement of the instrument such as function generator and oscilloscope.
Step 1.1, arrange amplitude and frequency that input removes the sine voltage signal of the preemphasis circuit of resistance and electric capacity, the initial value of frequency is 0Hz.
Step 1.2, inputs the sine voltage signal of current setting to the preemphasis circuit removing resistance and electric capacity.
As shown in Figure 2, at R
1, R
2, C
1, and C
2when removing, the sine voltage signal of the setpoint frequency that function generator produces is as V
inbe input to preemphasis circuit.The photoelectric detector of the light receiving end that LED sends is converted to current signal, is then converted to voltage signal by preamplifier, observes this output voltage signal V by oscilloscope
out, record frequency and the output voltage V of current test input voltage signal
outamplitude.In Fig. 2, in Error Detector, pattern generator produces 2
31-1 pseudo-random binary sequence (PRBS) inputs V
inend, utilizes error detector in Error Detector to carry out error detection at output.
Step 1.3, judge whether to obtain the test data on m Frequency point, m is positive integer, set as required, if not, the amplitude maintaining the sine voltage signal of input is constant, with the frequency of the frequency interval set as step value change sine voltage signal, selects the sine voltage signal of next frequency as V
intest, the amplitude of new sine voltage signal should remain unchanged, and continues to perform step 1.2.If so, obtain abundant test data, calculate input voltage on each Frequency point and, to the decay of output voltage, obtain an attenuation versus frequency curve.Decay represents with dB.
The frequency of input signal is from 0Hz, and be spaced apart step value with setpoint frequency and change, such as frequency interval is set to 5MHz, then the frequency of the sine voltage signal inputted is followed successively by 0Hz, 5MHz, 10MHz, 15MHz ... ..5 (m-1) MHz.The Frequency point scope measured at least will cover the target bandwidth wanted, and last frequency values measured must be greater than balanced target frequency value.
Step 1.4, setting decay minimum frequency point decays to 0, and attenuation versus frequency curve step 1.3 obtained, along decay direction translation, obtains a normalized attenuation versus frequency curve.Fig. 3 is an example of this step test result.
Step 2, the attenuation versus frequency curve phase matching gain-frequency curve of preemphasis network and step 1 being obtained by least square method.
Step 2.1, analyzes preemphasis circuit, obtains the gain versus frequency function of preemphasis circuit, is normalized by gain-frequency curve.With similar to the normalization of attenuation versus frequency curve, the gain on setting gain minimum frequency point is 0, by gain-frequency curve along gain direction translation, obtains a normalized gain-frequency curve.
R-C network, R in the embodiment of the present invention
g, R
fwith amplifier A
1the amplification network of composition can produce the gain with frequency change, and this gain versus frequency function can be obtained by analysis circuit, and in preemphasis network, the value of electric capacity and resistance is the parameter in this gain versus frequency function.
The gain-frequency curve of preemphasis circuit shown in Fig. 1 can be represented as:
Can draw from formula (2), gain except outside the Pass having with circular frequency ω, also and R
1, R
2, C
1and C
2etc. parameter correlation.This gain-frequency curve is normalized.
Step 2.2, makes normalized gain-frequency curve and normalized attenuation versus frequency curve carry out matching by least square method, obtains the value of optimized resistance and electric capacity.
The resolving ideas that the present invention proposes carrys out the attenuation versus frequency curve obtained in matching second step.Optimized R is asked in this process by least square method
1, R
2, C
1and C
2value.According to least square method, the residual sum of squares (RSS) of embodiment of the present invention gain-frequency curve and attenuation versus frequency curve can be expressed as formula:
S＝∑
i[G
N(f
i,R
1,R
2,C
1,C
2)-A
N(f
i)]
2(3)
Wherein f
ifrequency, each frequency measured in corresponding step 2, i=1,2 ..., m.G
nf
ifunction, be that the normalization of the gain that formula (2) is predicted represents.R
1, R
2, C
1and C
2the resistance in preemphasis circuit and capacitance.A
nit is the expression after the attenuation versus frequency curve normalization of measuring in step 1.G after normalization
nand A
nall positive.Solve optimum R
1, R
2, C
1and C
2value, make S value minimum.R now
1, R
2, C
1and C
2the value will found exactly.Fig. 4 is the effect schematic diagram of a kind of matching using this method to obtain, and the curve in figure representated by Attenuation is attenuation versus frequency curve, and the curve representated by Gain is the gain-frequency curve of preemphasis circuit.
By normalized, convenient process decay and the value of gain when matching.When process of fitting treatment, the gain that preemphasis network provides on certain Frequency point does not need just in time equal with decay on this Frequency point, as long as gain deducts after decay not with frequency change.
The E/O/E frequency spectrum of the preemphasis circuit of the resistance that lower planar survey uses the inventive method to obtain and electric capacity.
The embodiment of the present invention is obtaining R
1, R
2, C
1and C
2optimal solution after, corresponding device is welded on circuit board, then the E/O/E amplitude-frequency response of test macro, just can obtains the amplitude frequency diagram after equilibrium.Fig. 5 is the result example using this method to obtain, as can be seen from the figure, use this method amplitude-versus-frequency curve carried out after preemphasis to compare not add the amplitude-versus-frequency curve under pre-emphasis case, the E/O/E bandwidth of system has been expanded, and very smooth in passband.
This method not only can be used for designing preemphasis circuit, also can be used for designing post-equalization circuit.Post-equalization circuit and preemphasis circuit have identical topological structure.When preemphasis and post-equalization circuit exist simultaneously, the inventive method also can be used to determine optimum resistance and capacitance.
Use commercially available blue led in an experiment, the transmission range of experiment is 45 centimetres, is converted to the signal of telecommunication, observes waveform by oscilloscope by a Φ 25.4 millimeters of lens focus to a 150MHzPIN photoelectric detector.
Before pre-equalization circuit is not added in test, system E/O/E smaller bandwidth, in the method using the present invention to adopt, after calculating the resistance capacitance value of preemphasis circuit, calculated value is applied in preemphasis circuit, make the three dB bandwidth of system reach 130MHz, the decay simultaneously in 110MHz only has 0.4dB.Result as shown in Figure 5.
Use the communication system of the inventive method design, in 100Mbps, 200Mbps and 300Mbps pseudorandom pattern test transmission, eye pattern is clear, excellent performance, and result as shown in Figure 6.In Fig. 6, (a) is the eye pattern obtained in 100Mbps pseudorandom pattern test transmission after the preemphasis circuit using the present invention to obtain; B () is the eye pattern obtained in 200Mbps pseudorandom pattern test transmission after the preemphasis circuit using the present invention to obtain; C () is the eye pattern obtained in 300Mbps pseudorandom pattern test transmission after the preemphasis circuit using the present invention to obtain.
As shown in Figure 7, be the embodiment of the present invention, use the schematic diagram of preemphasis and equalizing circuit simultaneously.In Fig. 7, the sine voltage signal that function generator produces is as V
inbe input to preemphasis circuit.The photoelectric detector of the light receiving end that LED sends is converted to current signal, is then converted to voltage signal by preamplifier, and the voltage signal input post-equalization circuit of conversion, observes the voltage signal V of post-equalization circuit output by oscilloscope
out.
As shown in Figure 8, after using preemphasis and equalizing circuit simultaneously, obtain bandwidth be expanded after amplitude-frequency characteristic figure.Therefrom can find out, adopt the resistance capacitance value that the inventive method obtains, it is simultaneously more smooth in passband that the preemphasis equalizing circuit obtained when applying has wider bandwidth.Normalized gain-frequency curve that preemphasis and equalizing network produce with do not carry out preemphasis and balanced time measured normalization attenuation versus frequency curve phase matching; And the E/O/E amplitude-versus-frequency curve that will obtain after the use preemphasis predicted in theory and equalizing network, also differs the E/O/E amplitude-versus-frequency curve of acquisition from very little with after the use preemphasis of actual measurement and equalizing network.
Test Fig. 7, the error rate obtained and eye pattern are as shown in Figure 9.Eye pattern is clear as can be seen from Figure 9, and only uses compared with preemphasis circuit, and traffic rate gets a promotion.
Claims (1)
1. the preemphasis based on least square method and equalization methods, it is characterized in that, be applied to the LED drive circuit of the preemphasis circuit realized based on resistance and electric capacity, wherein preemphasis circuit is n rank, comprise n branch road in parallel, each branch road is the series circuit of a resistance and an electric capacity, and n is positive integer; The input voltage of preemphasis circuit is designated as V
in; Described is obtain resistance R in n branch road based on the preemphasis of least square method and the object of equalization methods
1..., R
nwith electric capacity C
1..., C
nvalue, performing step is as follows:
Step 1, removes the resistance in the branch road of n in preemphasis circuit and electric capacity, measures the attenuation versus frequency curve in the E/O/E response not using preemphasis circuit; E/O/E represents electrical-optical-electricity;
Step 1.1, arranges amplitude and the frequency of sine voltage signal, and the initial value of frequency is 0Hz;
Step 1.2, the sine voltage signal of current setting is inputted to the preemphasis circuit removing resistance and electric capacity, the photoelectric detector of the light receiving end that LED sends is converted to current signal, is then converted to voltage signal by preamplifier, records the amplitude of the output voltage signal obtained;
Step 1.3, judges whether to obtain the data on m Frequency point, and if not, the amplitude maintaining the sine voltage signal of input is constant, with the frequency of the frequency interval set as step value change sine voltage signal, then continues step 1.2; If so, calculate input voltage on each Frequency point and, to the decay of output voltage, obtain an attenuation versus frequency curve; Wherein, m is positive integer;
Step 1.4, setting decay minimum frequency point decays to 0, by attenuation versus frequency curve along decay direction translation, obtains a normalized attenuation versus frequency curve;
Step 2, the normalized attenuation versus frequency curve phase matching gain-frequency curve of preemphasis network and step 1 being obtained by least square method, asks for the value of resistance and electric capacity in n branch road;
Step 2.1, is normalized the gain-frequency curve of preemphasis network, and the gain on setting gain minimum frequency point is 0, by gain-frequency curve along gain direction translation, obtains a normalized gain-frequency curve;
Step 2.2, makes normalized gain-frequency curve and normalized attenuation versus frequency curve carry out matching by least square method, obtains the value of optimized resistance and electric capacity;
Wherein, the target function value S of least square method is expressed as:
Ask for n the resistance R making S minimum
1..., R
nand n electric capacity C
1..., C
n, f
irepresent i-th frequency, i=1,2 ..., m; G
nf
ifunction, represent the gain-frequency curve of normalized preemphasis circuit; A
nrepresent the normalized attenuation versus frequency curve that step 1 obtains.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106413191A (en) * | 2016-10-21 | 2017-02-15 | 天津大学 | LED drive circuit with high speed and high conversion efficiency for visible light communication |
| CN106941377A (en) * | 2017-02-22 | 2017-07-11 | 华南理工大学 | Photelectric receiver method for designing for improving visible light communication medium-high frequency gain |
| CN107241160A (en) * | 2016-03-28 | 2017-10-10 | 华为技术有限公司 | The method and apparatus for determining parameter |
| CN107592163A (en) * | 2017-09-11 | 2018-01-16 | 东南大学 | Optimal LED serial number method for determination of amount in optical communication system |
| CN109391324A (en) * | 2017-08-02 | 2019-02-26 | 天津大学 | A kind of LED driving specific integrated circuit for visible light communication transmitter |
| CN112668275A (en) * | 2020-12-31 | 2021-04-16 | 芯和半导体科技(上海)有限公司 | Method for searching optimal substitute target capacitance in given capacitance set |
| CN115051752A (en) * | 2022-06-21 | 2022-09-13 | 中国科学院半导体研究所 | Communication link and bandwidth expanding method of fluorescent LED in communication link |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1996975A (en) * | 2006-12-28 | 2007-07-11 | 华为技术有限公司 | A signal measurement device, system and method |
| CN101588210A (en) * | 2008-05-20 | 2009-11-25 | 调谐公司 | Dispersion compensation circuitry and system for analog video transmission with direct modulated laser |
| US9077300B1 (en) * | 2014-10-27 | 2015-07-07 | King Fahd University Of Petroleum And Minerals | Predistortion circuit with concave characteristic |
-
2015
- 2015-09-18 CN CN201510598427.0A patent/CN105282068B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1996975A (en) * | 2006-12-28 | 2007-07-11 | 华为技术有限公司 | A signal measurement device, system and method |
| CN101588210A (en) * | 2008-05-20 | 2009-11-25 | 调谐公司 | Dispersion compensation circuitry and system for analog video transmission with direct modulated laser |
| US9077300B1 (en) * | 2014-10-27 | 2015-07-07 | King Fahd University Of Petroleum And Minerals | Predistortion circuit with concave characteristic |
Non-Patent Citations (2)
| Title |
|---|
| HONGLEI LI 等: "High Bandwidth Visible Light Communications Based on a Post-Equalization Circuit", 《IEEE PHOTONICS TECHNOLOGY LETTERS》 * |
| 韦佼宜: "室内可见光通信系统设计、电路均衡与实测", 《硕士论文》 * |
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| CN113114414B (en) * | 2016-03-28 | 2022-07-12 | 华为技术有限公司 | Method and device for determining parameters |
| CN107241160B (en) * | 2016-03-28 | 2021-03-23 | 华为技术有限公司 | Method and device for determining parameters |
| CN106413191A (en) * | 2016-10-21 | 2017-02-15 | 天津大学 | LED drive circuit with high speed and high conversion efficiency for visible light communication |
| CN106941377A (en) * | 2017-02-22 | 2017-07-11 | 华南理工大学 | Photelectric receiver method for designing for improving visible light communication medium-high frequency gain |
| CN106941377B (en) * | 2017-02-22 | 2023-07-18 | 华南理工大学 | Photoelectric receiver design method for improving high-frequency gain in visible light communication |
| CN109391324B (en) * | 2017-08-02 | 2022-02-01 | 天津大学 | LED drive special integrated circuit for visible light communication transmitter |
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| CN107592163B (en) * | 2017-09-11 | 2020-04-24 | 东南大学 | Method for determining optimal serial number of LEDs in optical communication system |
| CN107592163A (en) * | 2017-09-11 | 2018-01-16 | 东南大学 | Optimal LED serial number method for determination of amount in optical communication system |
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