CN100344084C - Device for conducting position detection using modulation light beam and detection method - Google Patents
Device for conducting position detection using modulation light beam and detection method Download PDFInfo
- Publication number
- CN100344084C CN100344084C CNB2005100390395A CN200510039039A CN100344084C CN 100344084 C CN100344084 C CN 100344084C CN B2005100390395 A CNB2005100390395 A CN B2005100390395A CN 200510039039 A CN200510039039 A CN 200510039039A CN 100344084 C CN100344084 C CN 100344084C
- Authority
- CN
- China
- Prior art keywords
- square wave
- signal processing
- chip
- light
- beacon
- 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.)
- Expired - Fee Related
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 14
- 238000012545 processing Methods 0.000 claims abstract description 52
- 238000006243 chemical reaction Methods 0.000 claims abstract description 4
- 238000001914 filtration Methods 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 12
- 230000003321 amplification Effects 0.000 claims description 9
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 9
- 230000004044 response Effects 0.000 claims description 8
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000010363 phase shift Effects 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- 238000005070 sampling Methods 0.000 claims description 2
- 230000006854 communication Effects 0.000 description 15
- 238000004891 communication Methods 0.000 description 14
- 230000003287 optical effect Effects 0.000 description 9
- 230000035945 sensitivity Effects 0.000 description 6
- 230000006870 function Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000001447 compensatory effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Images
Landscapes
- Optical Radar Systems And Details Thereof (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The present invention discloses a position detecting device which utilizes modulated light beams. A signal processing circuit of the present invention is a position sensing detector, each base pin of the position sensing detector is connected in series with an I/V converter, a multiplier, a low-pass filter and an analogue-digital converter, four paths are connected with a single chip computer in parallel, the analogue-digital converter of one path is connected with the feedback end of a square wave generator, and the output end of the square wave generator is connected with the input end of the multiplier of each path. The detection method of the present invention comprises: beacon light of the transmitting end is transmitted by determined frequency square wave modulation; the position sensing detector of the receiving end receives and outputs to the I/V converter, the generated square wave of the square wave generator is input to the multiplier to be calculated, results are processed by low-pass filtering and analogue-digital conversion, and are divided into four paths to input in the single chip computer, and then, position information is evaluated; the analogue-digital conversion of one path is output to the square wave generator to be used for feedback control. Because input signals are processed by square wave modulation and differential processing by the multiplier and the filter, the present invention eliminates the background noise and the dark current, reduces the errors of output signals, enhances the detection precision of a system.
Description
One, technical field
The present invention relates to a kind of object be carried out the device of position sensing particularly a kind of detection method that utilizes device that modulated beam of light carries out position sensing and this device to adopt.
Two, background technology
Free space optical communication technology (FSO) is a kind of communication of realizing point-to-point communication by the unidirectional or bi-directional of laser beam, have the speed of optical fiber communication and do not need and aspect the such scarce resource of frequency spectrum very big initial outlay is being arranged, therefore obtained people's favor, made it become the important supplement of optical fiber communication and electric wave radio communication.Its application relates to backbone network, Access Network, local area network (LAN), is particularly suitable for also that emergency communication, fastext are opened, military security communication, special occasions communication etc., and its advantage is that bandwidth can be expanded, and construction speed is fast, and very economical.
Spatial beam to catch, follow the tracks of, aim at (ATP:acquisition tracking pointing) device be one of key equipment of free space optical communication, it launches beacon beam by the transmitting terminal in the both-end communication, catch this transmitting terminal by receiving terminal according to the position of beacon beam, and realize following the tracks of.The precision of ATP device work has determined the stability and the reliability of communication in the free space optical communication process.This device has two major functions: position error signal extracts and servo electrical machinery system control.The extraction of position error signal wherein partly is unusual the key link in the ATP device, and whether its precision and sensitivity directly have influence on follow-up tracking effective.General A TP device all is made up of thick tracking subsystem and smart tracking subsystem two parts, and both are in conjunction with the contradiction that mainly solves the visual field and precision.In actual the use, for simplified system to reduce cost, generally adopt the mode of gun aiming device and position sensitive detector (PSD) combination, gun aiming device is finished the coarse alignment on the direction roughly, and the positional information of obtaining transmitting terminal with position sensitive detector is to finish fine alignment.
In the existing free-space optical communication system, position sensitive detector in the ATP device all is the mode that adopts direct detection in the detection application of position, in order to improve performance, generally adopt at optical lens and partly add the method for filter plate with filtering part bias light, yet because the dark current of position sensitive detector is generally all very big, the dark current of the position sensitive detector of 10 * 10mm has 200nA under the room temperature, add the influence of bias light, finally make the sensitivity of system have only-20dBm about, greatly limited the coverage of position sensing.Common compensatory approach is to improve the transmitting power of transmitting terminal beacon beam source laser device, and this is subjected to the restriction of laser performance and cost.In addition, aspect signal processing, also have employing that the transmitting terminal signal is modulated the sensitivity of method that improves detection, yet this requires receiving terminal and transmitting terminal to be operated under the common clock, this is unpractical in space optical communication system.
Three, summary of the invention
1, goal of the invention: the purpose of this invention is to provide a kind of device that utilizes modulated beam of light to carry out position sensing, this device has alliance detection accuracy and the sensitivity higher than prior art, in addition, also provides the detection method of this device.
2, technical scheme: the present invention utilizes modulated beam of light to carry out the device of position sensing, comprise antenna, transmitter unit, receiving element and control unit, wherein transmitter unit comprises beacon light source, beam-expanding collimation equipment, behind the beacon beam process beam-expanding collimation by the generation of beacon light source, launch by antenna; Receiving element comprises position sensitive detector and signal processing circuit, antenna receives to be sent on the position sensitive detector behind the beacon beam light signal is converted to current signal, the input signal treatment circuit is handled again, and the position deviation information that will obtain after will handling sends control unit to; Control unit comprises servo controller and servomechanism, servo controller receives the position deviation information from the signal treatment circuit, control servomechanism again and finish aligning to light beam, it is characterized in that: signal processing circuit comprises I/V transducer, phase position adjustable bipolar square wave generator, two quadrant analog multiplier, low pass filter, A/D converter and the signal processing single chip or the digital signal processing chip of multistage amplification; Each pin is connected in series the I/V transducer of a multistage amplification, a two quadrant analog multiplier, a low pass filter and an A/D converter respectively successively in four pins of position sensitive detector, last four the tunnel connect signal processing single chip or digital signal processing chip concurrently, connect control unit again by signal processing single chip or digital signal processing chip, wherein one tunnel A/D converter also connects with the feedback end of the described bipolar square wave of position adjustable mutually generator, and this square-wave generator output connects an input of each road multiplier respectively.
Square-wave generator can be made up of square wave generation single-chip microcomputer and supply convertor.
In addition, two quadrant analog multiplier, low pass filter, A/D converter and mutually the loop that constitutes of position adjustable bipolar square wave generator can replace by a single-chip microcomputer.
Detection method of the present invention, comprise at first and launch beacon beam by transmitting terminal, after the position sensitive detector of receiving terminal receives this beacon beam, passing to signal processing circuit handles, signal after the processing is imported servo controller again, finishes aligning to light beam by servo controller output control signal with the control servomechanism.The beacon beam of transmitting terminal adopts the square wave of determining frequency to modulate, and the signal processing of receiving terminal is to carry out according to the following steps:
1) after the position sensitive detector of receiving terminal receives the modulated beacon beam that sends from transmitting terminal, at first light signal is converted into current signal, export the I/V transducer of this current signal from an one pin, current signal is converted to the magnitude of voltage V of OK range to multistage amplification
i
2) use phase position adjustable bipolar square wave generator to produce a bipolar square wave V
p, amplitude is+1 ,-1, frequency is consistent with the frequency of transmitting terminal square-wave frequency modulation;
3) with V
i, V
pInsert in a two quadrant analog multiplier and carry out computing, and the result of computing imported in a low pass filter or the integrator, thereby filtering is by the component that position sensitive detector dark current and background noise produce, and obtains fully the response voltage value Vo by beacon beam produced;
4) each pin in four pins of position sensitive detector is all adopted step 1)-3) method handle, obtain four fully by response amount that beacon beam produced, through parallel later on input signal processing single chip of digital sample or digital signal processing chip, carry out the position deviation information calculations and export to servo controller again by signal processing single chip or digital signal processing chip;
5) get wherein one tunnel output Vo to square-wave generator in order to FEEDBACK CONTROL V
pPhase place, make V
i, V
pPhase difference be zero.
Square-wave generator can be by square wave generation chip microcontroller, and its method is to give square wave generation single-chip microcomputer earlier with the digital signal that sampling obtains, and produces the controlled square wave of phase place by square wave generation single-chip microcomputer, obtains the controlled bipolar square wave of phase place with power conversion again.
The present invention is that the processing method of employing small-signal filters out background noise and the dark current in the position sensitive detector, to improve precision and the sensitivity that alliance is surveyed.
In the work, the interference that position sensitive detector receives mostly is natural daylight or artificial light, is characterized in that it is slowly that its brightness and orientation change, and the response that causes on position sensitive detector is direct current and low frequency component.If beacon beam is carried out the periodic square wave modulation, after position sensitive detector received signal, the photo-signal waveform of detected its any one pin roughly as shown in Figure 1.As shown in Figure 1, the electric current no beacon beam the time is caused by bias light and dark current; Electric current when beacon beam is arranged is caused jointly by bias light, dark current and beacon beam.When the response amount when beacon beam is arranged and the response amount when not having beacon beam do poorly, just eliminated the influence of time-independent basically background noise and dark current, obtained the electric current that causes by beacon beam fully.
3, beneficial effect: the present invention carries out from new design the signal processing circuit in the ATP system, by a multiplier signal of position sensitive device output and the bipolar square wave of square-wave generator output is multiplied each other the low level amount E when not having beacon beam like this
0With-1 multiply each other and become negatively, there have the high level amount E and+1 of beacon beam to multiply each other to be constant, just realized on average that by the filter addition both work differences handle again.By the characteristic of the related operation of signal as can be known, in the input signal, have only the component relevant just output can be arranged with bipolar square wave, just having only average in the input signal is that zero bipolar square wave component could pass through, other component can not pass through, and DC component is especially wherein also decayed greatly.So just eliminated the influence of background noise and dark current substantially, made that the positional information of calculating is more accurate, thereby improved alliance detection accuracy and sensitivity the input beacon beam.
Four, description of drawings
Fig. 1 is the signal waveform that receives modulation beacon beam PSD one pin.
Fig. 2 is the ATP system block diagram with independent beacon beam.
Fig. 3 is the signal processing circuit block diagram.
Fig. 4 adopts general single chip to replace the signal processing circuit block diagram in loop.
Fig. 5 is that the beacon beam signal of telecommunication and bipolar square wave are illustrated at the related operation waveform of out of phase difference ψ
When figure, a: ψ=π, b: ψ=π/6 o'clock, c: ψ=0 o'clock, d: the output after relevant and the relation of error angle.
Five, embodiment
As shown in Figure 2, it is ATP system block diagram with independent beacon beam, this system comprises common antenna, transmitter unit, receiving element and control unit, wherein transmitter unit comprises beacon light source, signal optical source, beam-expanding collimation device and closes wave plate, the beacon beam that produces by the beacon light source and pass through beam-expanding collimation separately by the flashlight that signal optical source produces after, two ways of optical signals merges into one the tunnel by closing wave plate, is launched by common antenna again; Receiving element comprises componemt wave plate, flashlight processing unit, position sensitive detector and signal processing circuit, the light beam that the space object that common antenna receives is launched also passes to componemt wave plate, isolate flashlight and beacon beam by componemt wave plate, wherein flashlight sends the flashlight sniffer to, beacon beam then sends position sensitive detector to and is converted to the signal of telecommunication, the input signal treatment circuit is handled afterwards, and the signal of telecommunication after will handling again sends control unit to; Control unit mainly comprises servo controller and servomechanism, servo controller receives the signal from signal processing circuit, and the control servomechanism is finished the aligning to spatial beam, signal processing circuit wherein is referring to Fig. 3, and it comprises I/V transducer, phase position adjustable bipolar square wave generator, two quadrant analog multiplier, low pass filter and the signal processing single chip or the digital signal processing chip of multistage amplification.Each pin is connected in series the I/V transducer of a multistage amplification, a two quadrant analog multiplier, a low pass filter and an A/D converter respectively successively in four pins of position sensitive detector, last four tunnel parallel connection signal processing single chip or digital signal processing chips connect control unit again by signal processing single chip or digital signal processing chip.Wherein one tunnel A/D converter connects with the feedback end of the described bipolar square wave of position adjustable mutually generator simultaneously, and this square-wave generator output connects an input of each road multiplier respectively.
As a kind of improvement of the present invention, two quadrant analog multiplier, low pass filter, A/D converter and mutually the loop that constitutes of position adjustable bipolar square wave generator can replace by a single-chip microcomputer, single-chip microcomputer can be realized the function in this loop by certain algorithm.Adopt single-chip microcomputer to replace the signal processing circuit in loop referring to Fig. 4.
Method of work of the present invention is earlier the beacon beam of transmitting terminal to be determined the square-wave frequency modulation of frequency, beacon beam after will modulating by emitter is again launched, after the position sensitive detector of receiving terminal receives this beacon beam, at first be translated into current signal, and from the output of four pins, the I/V converting unit that a multistage amplification is all sent in the output of its each pin is converted to current signal the magnitude of voltage V of OK range
i, it is made up of three parts:
V
i＝V
i0+S
i(t)+n
i(t)
S wherein
i(t) be that its function expression is with the bipolar square wave of beacon beam square-wave frequency modulation with the frequency homophase:
V
I0And n
i(t) be respectively DC component and low-frequency ac noise;
Simultaneously, user's wave producer produces a bipolar square wave V
p, amplitude is+1 ,-1, and frequency is consistent with the frequency of the square-wave frequency modulation of transmitting terminal, and its function expression is:
Then, with V
i, V
pInsert and to carry out computing in the analog multiplier of one two quadrant and obtain, multiplied result imports a low pass filter again or integrator takes out direct current and low frequency component obtains Vo.Both constitute a correlator.By the characteristic of the related operation of signal as can be known, V
iIn the signal, have only and V
pRelevant component just can have output, just V
iMiddle average is zero bipolar square wave component, and other component can not pass through, and DC component is especially wherein also decayed greatly; And the size of the value Vo of filter output is with V
i, V
pPhase difference cosine relation is arranged.The function expression of Vo is:
Therefore, just can be with exporting Vo FEEDBACK CONTROL V
pPhase place, when phase difference was zero, output reached maximum.This maximum V
OmaxWith in the signal of input when beacon beam is arranged and the difference E-E of the mean value during no beacon beam
0Corresponding relation is arranged.Referring to Fig. 4.
With of the processing of four pins of position sensitive detector through same procedure, obtain four fully by response amount that beacon beam produced, the parallel later on input signal processing single chip of digital sample, carry out positional information calculation and export to servo controller by signal processing single chip, finally by the aligning of servomechanism realization light beam.
In the signal processing circuit of reality, feedback control loop should removal search the maximum of output guarantees output simultaneously again be maximum, the two has certain contradiction, exports often to reach stable.Solve this contradiction for improving performance, input signal V
iTell the extensive search that a part is used for phase place in strict ratio, give the local bipolar square wave generator on that road of stable output the peaked phase bit timing that has that searches then, form a twin nuclei.Such one the tunnel is responsible for phase place follows the tracks of on a large scale, and another road provides peaked stable output.
The working method of square wave generation single-chip microcomputer is as follows in the square-wave generator:
Earlier wave file is deposited in the memory, positive half period is 1 entirely, and negative half-cycle is 0 entirely.Wave file in the square wave generation single-chip microcomputer sequential read access to memory also obtains square wave from port output.As want phase shift then according to the amount that will move corresponding certain step pitch of redirect in wave file, finally obtain the waveform of required phase place.
Claims (6)
1, a kind of device that utilizes modulated beam of light to carry out position sensing, comprise antenna, transmitter unit, receiving element and control unit, wherein transmitter unit comprises beacon light source, beam-expanding collimation equipment, behind the beacon beam process beam-expanding collimation by the generation of beacon light source, is launched by antenna; Receiving element comprises position sensitive detector and signal processing circuit, antenna receives to be sent on the position sensitive detector behind the beacon beam light signal is converted to current signal, the input signal treatment circuit is handled again, and the position deviation information that will obtain after will handling sends control unit to; Control unit comprises servo controller and servomechanism, servo controller receives the position deviation information from the signal treatment circuit, control servomechanism again and finish aligning to light beam, it is characterized in that: signal processing circuit comprises I/V transducer, phase position adjustable bipolar square wave generator, two quadrant analog multiplier, low pass filter, A/D converter and the signal processing single chip or the digital signal processing chip of multistage amplification; Each pin is connected in series the I/V transducer of a multistage amplification, a two quadrant analog multiplier, a low pass filter and an A/D converter respectively successively in four pins of position sensitive detector, last four the tunnel connect signal processing single chip or digital signal processing chip concurrently, connect control unit again by signal processing single chip or digital signal processing chip, wherein one tunnel A/D converter also connects with the feedback end of the described bipolar square wave of position adjustable mutually generator, and this square-wave generator output connects an input of each road multiplier respectively.
2, the device that utilizes modulated beam of light to carry out position sensing according to claim 1 is characterized in that: two quadrant analog multiplier, low pass filter, A/D converter are replaced by a single-chip microcomputer with the loop that position adjustable bipolar square wave generator mutually constitutes.
3, the device that utilizes modulated beam of light to carry out position sensing according to claim 1 is characterized in that: the square-wave generator in the described signal processing circuit is made up of a square wave generation single-chip microcomputer and supply convertor.
4, the described detection method that utilizes modulated beam of light to carry out the device of position sensing of a kind of claim 1, comprise at first and launch beacon beam by transmitting terminal, after the position sensitive detector of receiving terminal receives this beacon beam, passing to signal processing circuit handles, signal after the processing is imported servo controller again, finish aligning by servo controller output control signal with the control servomechanism to light beam, it is characterized in that: the beacon beam of transmitting terminal adopts the square wave of determining frequency to modulate, and the signal processing of receiving terminal is to carry out according to the following steps:
1) after the position sensitive detector of receiving terminal receives the modulated beacon beam that sends from transmitting terminal, at first light signal is converted into current signal, from an one pin, export the I/V transducer of this current signal to one multistage amplification, current signal is converted to the magnitude of voltage V of OK range
i
2) simultaneously, use phase position adjustable bipolar square wave generator to produce a bipolar square wave V
p, amplitude is+1 ,-1, frequency is consistent with the frequency of transmitting terminal square-wave frequency modulation;
3) with V
i, V
pInsert in a two quadrant analog multiplier and carry out computing, and the result of computing imported in a low pass filter or the integrator, thereby filtering is by the component that position sensitive detector dark current and background noise produce, and obtains fully the response voltage value Vo by beacon beam produced;
4) each pin in four pins of position sensitive detector all according to step 1)-3) mode handle, obtain four fully by response amount that beacon beam produced, it is carried out parallel later on input signal processing single chip of digital sample or digital signal processing chip, carry out the position deviation information calculations and export to servo controller by signal processing single chip or digital signal processing chip;
5) get wherein one tunnel output Vo to square-wave generator in order to FEEDBACK CONTROL V
pPhase place, make V
i, V
pPhase difference be zero.
5, the method for work of utilizing modulated beam of light to carry out the device of position sensing according to claim 4, it is characterized in that: described square-wave generator is by square wave generation chip microcontroller, the digital signal that sampling obtains is given square wave generation single-chip microcomputer earlier, produce the controlled square wave of phase place by square wave generation single-chip microcomputer, obtain the controlled bipolar square wave of phase place with power conversion again.
6, the method for work of utilizing modulated beam of light to carry out the device of position sensing according to claim 5, the working method that it is characterized in that described square wave generation single-chip microcomputer is: earlier wave file is deposited in the memory, positive half period is 1 entirely, negative half-cycle is 0 entirely, wave file during the work of square wave generation single-chip microcomputer in the sequential read access to memory, and obtain square wave, as want phase shift then according to the certain step pitch of the corresponding redirect of the amount that will move from port output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100390395A CN100344084C (en) | 2005-04-25 | 2005-04-25 | Device for conducting position detection using modulation light beam and detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100390395A CN100344084C (en) | 2005-04-25 | 2005-04-25 | Device for conducting position detection using modulation light beam and detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1677901A CN1677901A (en) | 2005-10-05 |
| CN100344084C true CN100344084C (en) | 2007-10-17 |
Family
ID=35050230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100390395A Expired - Fee Related CN100344084C (en) | 2005-04-25 | 2005-04-25 | Device for conducting position detection using modulation light beam and detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100344084C (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101923001B (en) * | 2010-08-11 | 2011-12-14 | 哈尔滨工业大学 | Moving image modulation transfer function measuring method based on gray threshold segmentation algorithm |
| CN103384166B (en) * | 2013-07-02 | 2016-05-11 | 镇江奥菲特光电科技有限公司 | The fiber port line order tester of Optical Access Network |
| CN103499819B (en) * | 2013-09-22 | 2015-06-24 | 中国科学院光电技术研究所 | Measuring device and method for target line-of-sight angel offset and distance |
| CN104111083B (en) * | 2014-07-31 | 2017-03-15 | 中国科学院上海光学精密机械研究所 | The process circuit of Position-Sensitive Detector output signal and processing method |
| CN109839186A (en) * | 2019-02-21 | 2019-06-04 | 中国科学院光电技术研究所 | A kind of system and method improving space optical communication system light-beam position detection accuracy |
| CN109818678B (en) * | 2019-04-08 | 2019-11-05 | 烟台有光通信科技有限公司 | Visible data transceiver terminal |
| CN112212789B (en) * | 2019-07-12 | 2021-12-21 | 上海沃尔沃汽车研发有限公司 | Position detection system and position detection method |
| CN111121626B (en) * | 2019-12-30 | 2021-09-07 | 广东博智林机器人有限公司 | Signal detection circuit, position sensitive detector and position detection system |
| CN111121615B (en) * | 2020-01-02 | 2021-10-01 | 南京大学 | Phase shift interference fringe pattern batch selection method based on Hilbert transform |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5710652A (en) * | 1992-08-27 | 1998-01-20 | Trex Communications | Laser communication transceiver and system |
| CN1199963A (en) * | 1997-04-30 | 1998-11-25 | 美国电报电话公司 | Sensor array tracking and detection system |
| EP0881788A2 (en) * | 1997-05-30 | 1998-12-02 | Victor Company Of Japan, Limited | Optical receiver and related optical wireless transmission system |
| EP1450500A2 (en) * | 2003-02-18 | 2004-08-25 | Victor Company Of Japan, Ltd. | Optical axis adjusting device |
-
2005
- 2005-04-25 CN CNB2005100390395A patent/CN100344084C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5710652A (en) * | 1992-08-27 | 1998-01-20 | Trex Communications | Laser communication transceiver and system |
| CN1199963A (en) * | 1997-04-30 | 1998-11-25 | 美国电报电话公司 | Sensor array tracking and detection system |
| EP0881788A2 (en) * | 1997-05-30 | 1998-12-02 | Victor Company Of Japan, Limited | Optical receiver and related optical wireless transmission system |
| EP1450500A2 (en) * | 2003-02-18 | 2004-08-25 | Victor Company Of Japan, Ltd. | Optical axis adjusting device |
Non-Patent Citations (1)
| Title |
|---|
| 应用激光 王萍萍，艾勇，支新军，347-350，自由空间光通信终端机中ATP系统设计 2003 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1677901A (en) | 2005-10-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100344084C (en) | Device for conducting position detection using modulation light beam and detection method | |
| CN102594393A (en) | Universal pseudocode synchronization system of comprehensive satellite baseband equipment | |
| CN102155929A (en) | Displacement measuring device based on position-sensitive detector and application method of displacement measuring device | |
| CN102045036A (en) | Digital phase lock amplifier | |
| CN101242195B (en) | A constitution and its operation method for frequency spreading tracking loop | |
| CN110071738A (en) | Spread-spectrum signal based on more pseudo-code branch receivers de-spreads tracking | |
| CN108196307B (en) | Technical scheme for sine wave phase induced polarization | |
| CN102589419A (en) | Measurement method and measurement device based on PSD (Phase Sensitive Demodulator) | |
| CN110375727A (en) | A kind of closed-loop fiber optic gyroscope signal modulating method | |
| CN105629060A (en) | Grid frequency measurement method and device based on optimal baseband filtering | |
| CN100533063C (en) | Method for separating thermal noise, shot noise and intensity noise of optical fiber gyroscope | |
| WO2007049023A1 (en) | Signal processing and time delay measurement based on combined correlation and differential correlation | |
| CN1159589C (en) | AC signal measuring controller for power system | |
| US4020283A (en) | MSK digital data synchronization detector | |
| CN113074712B (en) | Optical fiber gyroscope loop gain optimization method | |
| CN110545102A (en) | all-digital low-level system based on digital phase-locked loop | |
| CN206292389U (en) | A kind of alignment system of mobile target | |
| CN110530407A (en) | A kind of photosignal quality error separation method of photoelectric encoder | |
| CN2491850Y (en) | Digital sampling device for power system a.c. signal | |
| CN1317845C (en) | Method and system for tracing signal route | |
| CN107505473B (en) | The soft decoding Computational Method of Velocity Measurement of motor based on phaselocked loop | |
| CN114325030A (en) | Double square wave modulation open-loop demodulation method based on optical current transformer | |
| CN106685633A (en) | Full-digital phase shift weak signal phase lock detection method and equipment | |
| CN111024651B (en) | Method for measuring relative wavelength of laser in wavelength modulation spectrum technology | |
| Zaiqun | Study on detection of weak signal by phase lock-in amplification |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |