CN108173601B - Weak light or long-distance single photon training detection system and detection method - Google Patents

Weak light or long-distance single photon training detection system and detection method Download PDF

Info

Publication number
CN108173601B
CN108173601B CN201711435594.9A CN201711435594A CN108173601B CN 108173601 B CN108173601 B CN 108173601B CN 201711435594 A CN201711435594 A CN 201711435594A CN 108173601 B CN108173601 B CN 108173601B
Authority
CN
China
Prior art keywords
training
photons
weak light
detection
single photon
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.)
Active
Application number
CN201711435594.9A
Other languages
Chinese (zh)
Other versions
CN108173601A (en
Inventor
汪涛
王超
朱义君
田忠骏
郑晓东
刘洛琨
梁进山
张东方
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dongguan Xinda Institute Of Integrated Innovation
Information Engineering University of PLA Strategic Support Force
Original Assignee
Dongguan Xinda Institute Of Integrated Innovation
Information Engineering University of PLA Strategic Support Force
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dongguan Xinda Institute Of Integrated Innovation, Information Engineering University of PLA Strategic Support Force filed Critical Dongguan Xinda Institute Of Integrated Innovation
Priority to CN201711435594.9A priority Critical patent/CN108173601B/en
Publication of CN108173601A publication Critical patent/CN108173601A/en
Application granted granted Critical
Publication of CN108173601B publication Critical patent/CN108173601B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/69—Electrical arrangements in the receiver
    • H04B10/691—Arrangements for optimizing the photodetector in the receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/516—Details of coding or modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/024—Channel estimation channel estimation algorithms

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Optical Communication System (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

The invention discloses a weak light or long-distance single photon training detection system and a detection method, the invention relates to a single photon detection technology used under the conditions of weak light signals, long distance and the like, and the system comprises the weak light or long-distance single photon training detection system, wherein data of a sending end comprises a known training bit 1 and other data sequences, single carrier OOK modulation is adopted, a receiving end needs a high-sensitivity photoelectric detection device, and a single photon avalanche diode SPAD is adopted; in addition, the invention also provides a weak light or long-distance single photon training detection method for detecting a single training symbol, and has the advantages that the single training bit '1' is used for carrying out channel estimation on the received signal, and the maximum likelihood detection is carried out on the received photon counting signal, so that the transmission performance of the system is improved.

Description

Weak light or long-distance single photon training detection system and detection method
Technical Field
The invention relates to the technical field of single photon detection under the conditions of weak light signals, long distance and the like, in particular to a weak light or long distance single photon training detection system and a detection method.
Background
For large indoor places, outdoor and underwater long-distance or weak light communication, an optical signal reaching a receiving end from a transmitting end is usually very weak, so that a high-sensitivity photoelectric detection device is required for the receiving end.
Thus, the single photon avalanche diode SPAD is widely used for the above communication systems due to its high sensitivity and high photodetection efficiency. The output of the SPAD is a photon counting signal, typically one photon per output pulse. However, most current SPAD-based studies model their photo-converted output as a standard Poisson statistical property of Poisson.
The SPAD operates in the geiger mode slightly above the breakdown voltage, the portion above which is called the over-bias voltage. When the geiger mode occurs discharge, the front-end circuit detects the avalanche current. Since the avalanche current is extremely large and would cause SPAD damage if not suppressed, the front-end circuit then reduces the bias voltage to stop avalanche breakdown, a process called quenching. Thus, the Time required for the SPAD to recover its photon detection capability is called Dead Time (Dead Time), which is the Time during which the SPAD cannot detect photons. The shorter the dead time, the more advantageous the detection. Dead time, greater than the transmission bit duration, will cause intersymbol interference.
Since it is shown from experimental observations and related research results that the actual SPAD output is not a Poisson distribution due to the presence of dead time effects, SPAD cannot detect photons when the system is at dead time.
Therefore, it is desirable to provide a weak light or long-distance single photon training detection system and detection method, which solve the above problems and improve the transmission performance of the system.
Disclosure of Invention
The invention aims to provide a weak light or long-distance single photon training detection system and a detection method, which are used for solving the problems of the background technology that the optimal precoding, equalization matrix and luminous flux distribution proportion can be achieved by searching the system illumination performance.
In order to achieve the purpose, the invention provides the following technical scheme:
a weak light or long-distance single photon training detection system and a detection method comprise a weak light or long-distance single photon training detection system and a weak light or long-distance single photon training detection method.
A weak light or long-distance single photon training detection system comprises a sending end and a receiving end;
the data of the sending end comprises a training bit '1' and a data sequence, single carrier OOK modulation is adopted, channel estimation is carried out on the received signal by using the single training bit '1', and then maximum likelihood detection is carried out on the received photon counting signal;
the receiving end adopts a single photon avalanche diode SPAD with high sensitivity and high photoelectric detection efficiency.
Preferably, the one training bit "1", and the data sequence, both constitute one frame structure.
Preferably, the data sequence is used for carrying effective data information.
Preferably, the training bit "1" is used to estimate the channel information, and then a threshold of maximum likelihood detection is given according to the given channel estimation value
A weak light or long-distance single photon training detection method, when SPAD is in dead time, SPAD can not detect photon, the dead time is shorter, the detection is more beneficial, if the dead time is longer than the transmission bit duration, intersymbol interference can be caused; therefore, a weak light or long-distance single photon training detection method,
the SPAD output model under dead time constraints is considered as:
Figure GDA0002362932980000031
Figure GDA0002362932980000032
τ is dead time, Tdδ is the dead time rate for the data bit duration.
Figure GDA0002362932980000033
For maximum count, SPAD number of photons equal to k appears for weak light detectionmaxThe probability of (a) is almost negligible. Thus simplifying the above formula as
Figure GDA0002362932980000034
Then, the channel information of the first training bit estimate can be expressed as
Figure GDA0002362932980000035
nbThe photons are counted due to background light noise and dark count noise. The noise photon count can be calculated by observing the noise photon count within a period of time and dividing by the corresponding time; y istThe training bit "1" corresponds to the number of photons received.
Then the actual maximum likelihood detection threshold is
Figure GDA0002362932980000036
λ1Denotes the number of photons, λ, if the symbol 1 is accepted0Indicating the number of photons if the symbol 0 is accepted.
Preferably, the probability distribution of the actual SPAD is a function related to the data rate.
Compared with the prior art, the invention has the beneficial effects that: the invention utilizes a single training bit 1 to carry out channel estimation on the received signal and carries out maximum likelihood detection on the received photon counting signal, thereby improving the transmission performance of the system.
Drawings
FIG. 1 is a data frame structure;
figure 2 is a sequence of photon counting pulses received by the SPAD.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-2, the present invention provides a technical solution:
a weak light or long-distance single photon training detection system and a detection method comprise a weak light or long-distance single photon training detection system and a weak light or long-distance single photon training detection method.
A weak light or long-distance single photon training detection system comprises a sending end and a receiving end; the data of the sending end comprises a training bit '1' and a data sequence, single carrier OOK modulation is adopted, channel estimation is carried out on the received signal by using the single training bit '1', and then maximum likelihood detection is carried out on the received photon counting signal; the receiving end adopts a single photon avalanche diode SPAD with high sensitivity and high photoelectric detection efficiency.
A weak light or long-distance single photon training detection method, when SPAD is in dead time, SPAD can not detect photon, the dead time is shorter, the detection is more beneficial, if the dead time is longer than the transmission bit duration, intersymbol interference can be caused; therefore, a weak light or long-distance single photon training detection method comprises the following steps:
the output model of SPAD under dead time limit is considered as
Figure GDA0002362932980000051
Figure GDA0002362932980000052
τ is dead time, Tdδ is the dead time rate for the data bit duration.
Figure GDA0002362932980000053
For maximum count, SPAD number of photons equal to k appears for weak light detectionmaxThe probability of (a) is almost negligible. Thus simplifying the above formula as
Figure GDA0002362932980000054
Then, the channel information of the first training bit estimate can be expressed as
Figure GDA0002362932980000055
nbThe photons are counted due to background light noise and dark count noise. The noise photon count can be calculated by observing the noise photon count within a period of time and dividing by the corresponding time; y istThe training bit "1" corresponds to the number of photons received.
Then the actual maximum likelihood detection threshold is
Figure GDA0002362932980000061
λ1Denotes the number of photons, λ, if the symbol 1 is accepted0Indicating the number of photons if the symbol 0 is accepted.
The working principle is as follows:
the frame structure comprises a unique training bit '1' and a subsequent data sequence, wherein the data sequence is used for bearing effective data information, the training bit '1' is used for estimating channel information, and then a threshold of maximum likelihood detection is given according to the given channel estimation value; in addition, the probability distribution of the actual SPAD can be a function related to the data rate, thereby being beneficial to improving the performance of the subsequent algorithm.
Interpretation of terms:
1. VLC (visible light communication) visible light communication;
2. a Lighting Emitting Diode (LED);
3. SPAD (single photon avalanche diode) single photon avalanche diode;
4. OOK (on-off-keying) on-off keying.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims (6)

1. A weak light or long-distance single photon training detection system comprises a sending end and a receiving end, and is characterized in that,
the data of the sending end comprises a training bit '1' and a data sequence, single carrier OOK modulation is adopted, channel estimation is carried out on the received signal by using the single training bit '1', and then maximum likelihood detection is carried out on the received photon counting signal;
the receiving end adopts a single photon avalanche diode SPAD with high sensitivity and high photoelectric detection efficiency;
the output model of SPAD under dead time limitation is
Figure FDA0002362932970000011
Figure FDA0002362932970000012
τ is dead time, TdFor data bit duration, delta is the dead time rate,
Figure FDA0002362932970000013
is the maximum count value; for weak light detection, the presence of SPAD output photons equal to kmaxNeglects the probability of (A), simplifies the above formula as
Figure FDA0002362932970000014
The channel information of the first training bit estimate is represented as
Figure FDA0002362932970000015
nbCounting photons caused by background light noise and dark counting noise by observing noise photons within a period of time and dividing the counted photons by corresponding time; y istFor training bits "1" to correspond to the number of photons received,
the actual maximum likelihood detection threshold is
Figure FDA0002362932970000021
λ1Denotes the number of photons, λ, if the symbol 1 is accepted0Indicating the number of photons if the symbol 0 is accepted.
2. The weak light or long range single photon training detection system of claim 1 wherein said training bit "1" and data sequence are combined into a frame structure.
3. The weak light or long distance single photon training detection system of claim 1 wherein said data sequence is used to carry valid data information.
4. The weak light or long distance single photon training detection system of claim 1 wherein said training bit "1" is used to estimate the channel information and then to give the threshold for maximum likelihood detection based on the given channel estimate.
5. A weak light or long-distance single photon training detection method is characterized in that,
the output model of SPAD under dead time limitation is
Figure FDA0002362932970000022
Figure FDA0002362932970000023
τ is dead time, TdFor data bit duration, delta is the dead time rate,
Figure FDA0002362932970000024
is the maximum count value; for weak light detection, the presence of SPAD output photons equal to kmaxNeglects the probability of (A), simplifies the above formula as
Figure FDA0002362932970000031
The channel information of the first training bit estimate is represented as
Figure FDA0002362932970000032
nbCounting photons caused by background light noise and dark counting noise by observing noise photons within a period of time and dividing the counted photons by corresponding time; y istFor training bits "1" to correspond to the number of photons received,
the actual maximum likelihood detection threshold is
Figure FDA0002362932970000033
λ1Indicating if a photon of sign 1 is acceptedNumber, lambda0Indicating the number of photons if the symbol 0 is accepted.
6. The method of claim 5 wherein the probability distribution of the actual SPAD is a function related to the data rate.
CN201711435594.9A 2017-12-26 2017-12-26 Weak light or long-distance single photon training detection system and detection method Active CN108173601B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201711435594.9A CN108173601B (en) 2017-12-26 2017-12-26 Weak light or long-distance single photon training detection system and detection method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201711435594.9A CN108173601B (en) 2017-12-26 2017-12-26 Weak light or long-distance single photon training detection system and detection method

Publications (2)

Publication Number Publication Date
CN108173601A CN108173601A (en) 2018-06-15
CN108173601B true CN108173601B (en) 2020-04-28

Family

ID=62521681

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201711435594.9A Active CN108173601B (en) 2017-12-26 2017-12-26 Weak light or long-distance single photon training detection system and detection method

Country Status (1)

Country Link
CN (1) CN108173601B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114285463B (en) * 2021-11-24 2023-04-07 中国人民解放军战略支援部队信息工程大学 SPAD high-speed receiving method based on external gating anti-ISI interference

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101873279A (en) * 2010-06-18 2010-10-27 南开大学 Method for channel estimation of multi-template ultra-wide bandwidth based on frame-level sampled data

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101149597A (en) * 2007-11-08 2008-03-26 华东师范大学 APD single photon detection control module
CN101860358A (en) * 2010-06-12 2010-10-13 中国科学技术大学 Single-photon counting system and counting method
WO2014001984A1 (en) * 2012-06-29 2014-01-03 Koninklijke Philips N.V. Dynamic modeling of imperfections for photon counting detectors
CN105606232B (en) * 2016-01-28 2019-03-12 中国人民解放军信息工程大学 A kind of realization method and system detecting optical signal
CN107359935B (en) * 2017-07-11 2019-06-11 中国科学技术大学 A kind of ultraviolet scatter communication system of non line of sight based on step-by-step counting and its method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101873279A (en) * 2010-06-18 2010-10-27 南开大学 Method for channel estimation of multi-template ultra-wide bandwidth based on frame-level sampled data

Also Published As

Publication number Publication date
CN108173601A (en) 2018-06-15

Similar Documents

Publication Publication Date Title
CN107271036B (en) The free-running operation single-photon detection system that high speed is quenched and restores
Li et al. Nonlinear distortion in SPAD-based optical OFDM systems
CN107359935A (en) A kind of ultraviolet scatter communication system of non line of sight based on step-by-step counting and its method
CN102098111A (en) Underwater voice communication system through light-emitting diode (LED) light source and diving helmet
CN107888295A (en) A kind of dim light communication control processor and communication means based on photon counting
Ji et al. Experimental study of SPAD-based long distance outdoor VLC systems
CN108173601B (en) Weak light or long-distance single photon training detection system and detection method
CN113422645A (en) Pulse width modulation system and method
CN107872278A (en) A kind of underwater visible light communication sensor network system of multidimensional based on ranging localization
Lee et al. A dual-receiving visible-light communication system under time-variant non-clear sky channel for intelligent transportation system
Nabavi et al. Performance analysis of air-to-water optical wireless communication using spads
CN105471505A (en) Signal modulation method, signal modulation device, and visible light communication system
CN102208943B (en) Demodulation method used for laser communication
Lu et al. Experimental investigation of underwater weak optical communication using a photomultiplier tube receiver
Mu et al. Evaluation and experimental comparisons of different photodetector receivers for visible light communication systems under typical scenarios
Wang et al. Multiple-symbol detection for practical SPAD-based VLC system with experimental proof
CN108282226B (en) A kind of synchronous method applied to photon counting visible light communication system
Zhang et al. Efficient pulse amplitude modulation for SPAD-based receivers
Li et al. Visible light communication performance in weak illumination environment
CN113726446B (en) Signal synchronization and extraction method based on photon counting communication
Huang et al. Quantum limited optical receivers in the presence of intersymbol interference
CN111060198B (en) Gating sampling front-end circuit compatible with laser radar linear/Geiger mode
Dai et al. Signal demodulation method for underwater optical wireless communication by measuring the time interval between adjacent photons
Yang et al. New receiver designs for underwater wireless optical communications
Jang et al. A LED Light Communication Transceiver Module for Ubiquitous Sensor Networks

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant