Portable wireless optical communication device and communication control method adaptive to communication distance

Abstract

The application relates to a portable wireless optical communication device with adaptive communication distance and a communication control method. The device integrates optical communication and telescopic imaging, realizes imaging and communication integration, and is coupled through the design of a visible light divergence angle and an infrared divergence angle and the high-density design of a communication unit. Based on a visible light and communication light common front-end optical system scheme, the system volume and weight are greatly reduced by multiplexing optical mechanical structures, an objective lens and a dichroic mirror. The communication control method overcomes the influence of communication distance changes, alignment errors and atmospheric channels on communication performance through "adaptive gain" and "adaptive threshold". The weight of an existing portable atmospheric laser communication terminal can be reduced to sub-kilogram level, handheld application is realized, the adaptive communication distance is increased from a few hundred meters to 5 km, optical communication and visible light telescopic "on-the-move" are realized in a power change range of 80 dB, and the communication range of the portable atmospheric laser communication terminal is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication, in particular, to a portable wireless optical communication device and a communication control method with adaptive communication distance. BACKGROUND

[0002] The portable wireless optical communication device modulates service data onto an optical carrier to realize service data transceiving, voice communication, etc. The portable wireless optical communication device is generally composed of an integrated processor and an optical head, the former completes signal detection, photoelectric conversion, modulation and demodulation and service data extraction, and the latter completes beam shaping, beam shrinking, tracking and aiming to realize spatial optical signal receiving and transmitting. The portable wireless optical communication device has important applications in disaster relief, battlefield situation awareness, secure communication under radio silence conditions, high-reliability communication under electromagnetic interference environment, outdoor operation and exploration, etc.

[0003] The existing portable wireless optical communication device has the following problems:

[0004] 1. Small adaptive range of received signal strength. Atmospheric channel attenuation, turbulence and distance change between the transmitting and receiving ends have great influence on the optical communication terminal. Without considering the change of the atmospheric channel, the optical power at the receiving end differs by nearly 10000 times (80 dB) at a distance of several meters and several kilometers. However, the dynamic response range of the detector at the receiving end is limited (generally several dB), and the electronic gain multiple in the portable optical communication equipment is generally fixed. Thus, the large optical power dynamic range will result in signal saturation (several meters of communication distance) or being submerged by noise (several kilometers of communication distance).

[0005] 2. Poor portability. Although increasing the tracking and aiming servo system can solve the above-mentioned alignment problem, the tracking and aiming servo system must increase the sensors, actuators and controllers, so that the system is complex, and the volume, weight and power consumption are large, which cannot realize the miniaturization of the equipment.

[0006] 3. Difficulty in alignment between the transmitting and receiving ends. The common alignment method of wireless laser communication is a compound tracking strategy based on a mechanical turntable and a fast mirror to realize the fusion of coarse tracking and fine tracking. The volume and weight are large, which is not suitable for portable applications. The signal divergence angle and receiving field of view of the portable optical communication device are extremely small. The traditional solution is to place it on a stable tripod and use a manual aiming mirror to perform alignment, which greatly affects the use efficiency.

[0007] 4. Only static communication can be used. Under the premise that the transmitting angle and receiving field of view are extremely small, the transmitting and receiving ends are generally fixed for point-to-point static communication. The relative motion between the transmitting and receiving ends will cause inconsistency in the pointing direction, thereby causing disconnection of the communication link, which is not suitable for use on a moving platform (vehicle-mounted, ship-mounted, single soldier marching). SUMMARY

[0008] To overcome at least one of the deficiencies in the prior art, the present application provides a portable wireless optical communication device and a communication control method with adaptive communication distance.

[0009] In a first aspect, a communication control method for a portable wireless optical communication device with adaptive communication distance is provided, comprising:

[0010] Step 11, smoothing filtering the received digital signals in multiple sampling periods to obtain filtered digital signals;

[0011] Step 12, calculating the absolute value of the average value V1 of the high-level data in the filtered digital signals;

[0012] Step 13, determining the size relationship between the absolute value and the binarization threshold value, if the absolute value is greater than or equal to the binarization threshold value, ending the adjustment, otherwise, executing step 14;

[0013] Step 14, determining the error Δ of the absolute value of the average value V1 and the binarization threshold value;

[0014] Step 15, judging whether the error Δ is greater than 0, if not, performing first-level gain adjustment with a step value of ɑ * V DD / 2 N , ɑ is a step factor, V DD is an amplifier voltage value, and N is the number of digital potentiometer bits, if yes, performing first-level gain adjustment with a step value of -ɑ * V DD / 2 N ;

[0015] Step 16, calculating the absolute value of the average value V2 of the high-level data in the filtered digital signals after gain adjustment, if the absolute value of the average value V2 is greater than or equal to the binarization threshold value, ending the adjustment, otherwise, returning to step 11 to perform next-level gain adjustment; and sequentially performing the gain adjustment until completing 4-level gain adjustment.

[0016] In one embodiment, the method further comprises updating the binarization threshold value.

[0017] In one embodiment, updating the binarization threshold value comprises:

[0018] placing signal data greater than an initial binarization threshold value V0 in multiple sampling periods as logic “1” and placing the remaining signal data as logic “0”;

[0019] calculating the average value V hi of the first set number P of logic “1” signal data, calculating the average value V li of the second set number Q of logic “0” signal data, and updating the binarization threshold value as Vi =(V hi +V li ) / 2;

[0020] Set the sliding window, the sliding window length ≤ min(P, Q), the sliding window slides for the signal data of multiple sampling periods, and for each sliding of the sliding window, calculate the updated binarization threshold V corresponding to the sliding window j , including: calculating the mean value V of the signal data of logic "1" in the sliding window after each sliding hj , and standard deviation δ, if V hj >V hi , updated binarization threshold V j =V i +δ, otherwise, V j =V i -δ.

[0021] In one embodiment, the method further comprises:

[0022] According to the updated binarization threshold V j , perform binarization processing on the signal data in the sliding window;

[0023] The binary processed signal data is error corrected and decoded to achieve signal reception and demodulation.

[0024] On the second aspect, a portable wireless optical communication device with adaptive communication distance is provided, including: a telescope optical machine body, an optical communication unit and an electronic unit, the telescope optical machine body is used to realize visible light telescope, the optical communication unit is used to realize the emission and reception of infrared light beams, and the electronic unit is used to realize the emission power control of the infrared light beam and the control of the infrared light beam receiving signal intensity.

[0025] In one embodiment, the electronic unit includes a signal processor for implementing the above-mentioned communication distance adaptive portable wireless optical communication control method.

[0026] In one embodiment, the electronics unit includes a signal processor configured to implement the following functions:

[0027] Performing smoothing filtering on the received digital signals within multiple sampling periods to obtain filtered digital signals;

[0028] The signal data in the filtered digital signal that is greater than the initial binary threshold V0 is set to logic "1", and the remaining signal data is set to logic "0";

[0029] Calculate the mean value V of the first set number P of logic "1" signal data hi , calculate the mean value V of the signal data of the second set number Q of logic "0"li The binary threshold is updated to V i = (V hi + V li ) / 2.

[0030] A sliding window is set, the length of the sliding window is less than or equal to min(P, Q), the sliding window slides on the signal data of multiple sampling periods, and for each sliding of the sliding window, the updated binary threshold V j corresponding to the sliding window is calculated, including calculating the mean value V hj and the standard deviation δ of the signal data of logical "1" in the sliding window after each sliding ends, if V hj >V hi , the updated binary threshold V j = V i + δ, otherwise, V j = V i - δ.

[0031] In one embodiment, the signal processor is further configured to implement the following functions:

[0032] According to the updated binary threshold V j , the signal data in the sliding window is binarized.

[0033] The binarized signal data is error corrected and decoded to realize the reception and demodulation of the signal.

[0034] In one embodiment, the electronic unit includes a signal transmitting module, a signal receiving module, and a main control module, the signal transmitting module includes a constant current driving circuit and a modulation circuit, the signal receiving module includes a preamplifier and a filter circuit, and the main control module includes a signal processor, an adjustable amplifier circuit, an analog-to-digital conversion circuit, a voice module, a sensitivity adjustment circuit, and an interface unit.

[0035] In one embodiment, the telescope light machine body includes two telescope barrel units, respectively denoted as a first telescope barrel unit and a second telescope barrel unit, the first telescope barrel unit includes a first lens barrel, and the first lens barrel has a first objective lens group, a first filter, a first turning mirror group, and a first eyepiece group arranged in sequence along the propagation direction of visible light; the second telescope barrel unit includes a second lens barrel, and the second lens barrel has a second objective lens group, a second filter, a dichroic mirror, a second turning mirror group, and a second eyepiece group arranged in sequence along the propagation direction of visible light.

[0036] In one embodiment, the optical communication unit includes an infrared light emitting branch and an infrared light receiving branch, the infrared light emitting branch includes a light source and an infrared objective lens, and the infrared light receiving branch includes a second objective lens group, a second filter, a dichroic mirror, a hot mirror, a beam reducer, a third filter, and a detector.

[0037] Compared with the prior art, the application has the following beneficial effects:

[0038] 1. The application fills the gap of a portable system integrating optical carrier-based communication and visible light telescopic imaging, realizes "seeing" and "communicating", and "accurately measuring". Traditional communication equipment and telescopic equipment are independent of each other, and two sets of equipment need to be carried. The application integrates optical communication and telescopic imaging, realizes the integration of imaging and communication based on the reasonable multiplexing of optical-mechanical structures and the design of a communication unit, and is particularly suitable for situation awareness and information high-privacy transmission under conditions such as single soldier equipment, outdoor exploration, rescue, radio silence, and the like.

[0039] 2. The application solves the problem of system lightness and miniaturization, does not need a special aiming device and independent beacon light, and does not need to wait for a chain building time, and is particularly suitable for portable application scenarios such as handheld and head-mounted. The system is designed through the coupling of the visible light divergence angle and the infrared divergence angle, the high-density design of the communication unit, and the visible light and communication light common front-end optical system scheme, multiplexes the optical-mechanical structure, the objective lens, and the dichroic mirror, and greatly reduces the system volume and weight.

[0040] 3. The application solves the problem that a traditional laser communication device cannot adapt to a large dynamic range change of received power. Through the "adaptive gain" and "adaptive threshold" methods on a portable terminal, the influence of communication distance change, alignment error, and an atmospheric channel on communication performance is overcome, the communication distance of an existing portable atmospheric laser communication terminal is improved from a few hundred meters to 5 km, real-time optical communication and visible light telescopic "mobile communication" in a power change range of 80 dB are realized, and the communication range of the portable atmospheric laser communication terminal is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] The application can be better understood by referring to the description given below in conjunction with the accompanying drawings, which are incorporated in and form a part of the specification, and together with the detailed description, serve to explain the principles of the application. In the drawings:

[0042] Figure 1 A structural schematic diagram of a communication distance adaptive portable wireless optical communication device according to an embodiment of the application is shown;

[0043] Figure 2 A structural schematic diagram of an infrared light receiving branch according to an embodiment of the application is shown;

[0044] Figure 3 A structural schematic diagram of an electronic unit according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0045] The exemplary embodiments of this application will be described hereinafter with reference to the accompanying drawings. In the description, all the features of the actual embodiments are not described for the sake of clarity and conciseness. It should be appreciated that many embodiment-specific decisions can be made in the process of developing any such actual embodiments to achieve the specific goals of the developers, and these decisions can vary from embodiment to embodiment.

[0046] It should also be noted that, in order to avoid obscuring the present application with unnecessary details, only the structures closely related to the scheme according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0047] It should be understood that the present application is not limited to the described embodiments by virtue of the following description with reference to the drawings. In this context, the embodiments can be combined with each other, features can be replaced or borrowed between different embodiments, and one or more features can be omitted in one embodiment.

[0048] The present application provides a portable wireless optical communication device with adaptive communication distance. In the process of communication among multiple observers, each observer holds a portable wireless optical communication device or wears the portable wireless optical communication device on the head. Each two observers carrying two portable wireless optical communication devices are paired with each other. The two paired observers are at a certain distance (which can be dynamically changed) and realize information transmission in motion. Wireless communication, ranging, visible light telescopic imaging and imaging can be realized. The communication distance range is dynamically changeable, and adaptive communication from several meters to several kilometers can be realized.

[0049] Figure 1 The structure schematic diagram of the portable wireless optical communication device with adaptive communication distance according to the embodiment of the present application is shown in FIG. 1. The device includes a telescopic light machine body, an optical communication unit and an electronic unit. The specific structure of each module is introduced as follows. Figure 1

[0050] ​The telescopic light machine body comprises two telescope barrel units, which are respectively referred to as a first telescope barrel unit and a second telescope barrel unit. The first telescope barrel unit comprises a first lens barrel, and the first lens barrel is sequentially provided with a first objective lens group, a first filter, a first turning mirror group and a first eyepiece group in the propagation direction of visible light. The second telescope barrel unit comprises a second lens barrel, and the second lens barrel is sequentially provided with a second objective lens group, a second filter, a dichroic mirror, a second turning mirror group and a second eyepiece group in the propagation direction of visible light. The dichroic mirror is designed based on a film system and can realize full projection (efficiency > 90%) of light signals with a wavelength less than 700 nm. The transmitted light signals enter the eyepiece group, and visible light telescoping is realized. Here, the objective lens group and the eyepiece group form a basic telescopic light path, and the turning mirror group rotates the inverted image formed by the objective lens into a positive image to facilitate eye observation. The lens barrel functions to fix various optical elements, circuit boards, battery boxes and the like. A user can realize observation of a remote target through the telescopic light machine body.

[0051] The telescopic light machine body of the embodiment can realize a magnification of a target of 2-10 times. Considering the portable requirement, the objective lens in the objective lens group can be selected as an objective lens with an aperture of 56 mm and a focal length of 184 mm. The eyepiece and the roof prism in the eyepiece group and the turning mirror group can be selected as a Kellner eyepiece with a focal length of 23 mm and a roof prism with a focal length of 23 mm, respectively, so as to realize miniaturization of the device. The length of the device is not greater than 160 mm, and the device is convenient to carry. In the embodiment, the core index of the telescopic light machine body design is: diopter adjustment ± 4, eye distance adjustment 60-76 mm, exit pupil distance > 22 mm.

[0052] The optical communication unit comprises an infrared light emitting branch and an infrared light receiving branch. The infrared light emitting branch is arranged on the main body of the optical telescope and is independent of the main body of the optical telescope. The infrared light is fixed on the main body of the optical telescope through a mechanical interface, is convenient to replace, can be replaced into different beam divergence angles, can adapt to different communication distances and different platform characteristics, and improves the applicability. The infrared light emitting branch comprises a light source and an infrared objective lens. The light source can be a light emitting diode (LED) or a laser diode (LD). The wavelength is outside the visible light range, and the wavelength of 900nm to 1550nm can be selected. Considering the maturity and cost of the device, 940nm and 1550nm are preferred. At the same time, considering the absolute safety of the human eye, the endurance time and other limitations, the pupil light power is strictly limited below 10mw. The infrared objective lens shapes the light beam emitted by the light source and emits according to a certain emission angle. The selection of the emission angle is directly related to the light power and the farthest communication distance. The divergence angle of the light beam can be designed to be between 1° and 10°. The infrared objective lens can be a beam reducer. The larger divergence angle emitted by the light source is reduced. The divergence angle and the field angle of the aforementioned optical telescope are within a certain proportional range. The range can ensure that the receiving end light power is large, and can ensure that the user on the opposite side is in most of the field of view of the telescope. A reasonable numerical proportional range realizes that "visible means available".

[0053] Figure 2 The structure of the infrared light receiving branch according to the embodiment of the application is shown. Referring to FIG. 4, the infrared light receiving branch comprises an infrared objective lens, an infrared filter, an infrared light receiving element, a signal processing circuit and a communication interface. Figure 2The infrared light receiving branch includes, in sequence along the propagation direction of the light beam, a second objective lens group, a second filter, a dichroic mirror, a hot mirror, a beam reducer, a third filter, and a detector, which is arranged in the off-axis direction of the visible light. The second telescope barrel unit shares the second objective lens group, the second filter, and the dichroic mirror with the infrared light receiving branch. After passing through the second objective lens group and the second filter, the light beam reaches the dichroic mirror, which reflects the light in the communication wave band (wavelength greater than 760 nm) to the hot mirror. The hot mirror reflects the light beam to the beam reducer, which is used to shape the light beam and reduce the received light spot diameter to 1 / 2 of the photosensitive surface size, thereby improving the signal-to-noise ratio. A narrow-band filter film is coated on the beam reducer, the center wavelength of the narrow-band filter film is the infrared signal light wavelength, and the bandwidth is ±20 nm. The detector can be an avalanche photodiode (APD) detector or a PIN photodetector in the infrared wave band, which converts the received infrared light signal into a weak electric signal. The photosensitive surface of the detector is as large as possible to improve the receiving field of view. In this embodiment, the infrared wave band APD photosensitive surface is 5 mm. It should be noted that the infrared light receiving branch can be integrated in the second telescope barrel unit. The infrared receiving branch can also be independent of the main body of the telescope optical machine and connected to the main body of the telescope optical machine through a hanging point, which is convenient to replace to realize different receiving field angles and adapt to different platform characteristics, such as communication in single soldier movement, communication in station platform movement, and communication in ship platform.

[0054] In this embodiment, the infrared light emitting branch and the infrared light receiving branch are arranged separately in physical space. The infrared light emitting branch can be an independent infrared light emitting machine structure, and different emitting components with different divergence angles can be replaced as needed. The separate arrangement of the two reduces the influence of backscattered light on reception and improves the signal-to-noise ratio.

[0055] Figure 3 A structural schematic diagram of an electronic unit according to an embodiment of the present application is shown, referring to Figure 3 The electronic unit includes a signal emitting module, a signal receiving module, and a main control module, and realizes emission power control of the infrared light beam and reception signal intensity control of the infrared light beam. The electronic unit is connected with the infrared light emitting branch and the infrared light receiving branch. The composition and functions of each module are introduced below.

[0056] The signal transmitting module comprises a constant current driving circuit and a modulation circuit. The constant current driving circuit comprises a metal-oxide-semiconductor field-effect transistor (MOSFET), a driver and a filter capacitor. The MOSFET can be SI4405, and the driver can be ADP3624, which is used to receive the PWM signal output by the signal processor in the master control module. The duty cycle of the MOSFET is adjusted, and the tuning range is (1%~99%). The "on-off" current becomes a constant current source after filtering. The maximum driving current of the constant current driving circuit is 100 mA, and the precision is 1 mA. The transmitting power regulation is realized by adjusting the duty cycle. The output power of the constant current driving circuit is automatically controlled by the signal processor according to the received optical power intensity, which is the transmitting gain control of the device. The modulation circuit is a MOSFET switching circuit, which is used to modulate the service data signal output by the signal processor on the constant current driving circuit, and the service data signal realizes the "on-off" control of the light source.

[0057] The signal receiving module comprises a preamplifier and a filter circuit. The preamplifier can be a transimpedance amplifier with the model number OPA657U. The weak current signal output by the detector is converted into a voltage signal, and the amplification gain is adjusted by the signal processor through a digital potentiometer. The transimpedance gain range is 100Ω~10MΩ, so that the first-stage gain adjustment of the receiving end is realized. The filter circuit plays a role in selecting the signal frequency passing through the circuit, filtering out the background light, improving the signal-to-noise ratio, and realizing longer-distance communication.

[0058] The master control module comprises a signal processor, an adjustable amplifier circuit, an analog-to-digital conversion circuit, a voice module, a sensitivity adjustment circuit and an interface unit. The signal processor can be ZYNQ7020 of XILINX Company, which is used to realize transmitting power control, receiving signal adaptive gain control, data encoding and decoding, automatic threshold binary extraction, etc. The sensitivity adjustment circuit comprises a high-voltage driver (model number LT8365) and a digital-to-analog converter (model number LTC2630). The voltage output by the digital-to-analog converter (model number LTC2630) is used to adjust the voltage output by the high-voltage driver (model number LT8365). The voltage output by the high-voltage driver (model number LT8365) is used as the working bias of the detector to adjust the multiplication factor of the detector, so that the second-stage gain adjustment of the receiving end is realized. The adjustable amplifier circuit comprises an amplifier (model number AD8338) and a digital-to-analog converter (model number LTC2630). The gain control of the signal amplitude in the electrical domain is realized by adjusting the amplification factor of the amplifier, that is, the third-stage gain adjustment of the receiving end is realized.

[0059] The analog electrical signal after three-stage gain is sent to an analog-digital conversion circuit and finally collected by a signal processor, and the signal amplitude is used as a condition for controlling the transmitting gain and the receiving gain to realize gain closed-loop control. The signal processing unit realizes adaptive communication to the receiving power variation caused by distance variation and pointing error through the receiving end three-stage gain and the transmitting gain.

[0060] In order to improve the signal-to-noise ratio and the communication distance, the RS error correction code is designed in the software of the signal processor, and the signal processor realizes adaptive amplification, baseband data extraction, geographic position information acquisition, ranging, etc. In addition, the signal processor can realize data communication with the external device through the external communication interface (network interface, USB, earphone), and also supports external gain setting.

[0061] The interface unit includes an audio codec module, a network module, a USB module, and indicator lights, a battery, an earphone, a microphone, etc. The audio codec module can be WM8731, which integrates audio ADC acquisition and DAC playback and earphone driving, and can realize microphone voice signal acquisition and earphone playback. A human-computer interface is designed to facilitate the rapid alignment and communication of the transmitting and receiving parties, and the change trend of the received signal strength is reminded by the buzzer sound and the flicker frequency of the indicator light. The network module uses the 88E1116 PHY chip of Marvell Company, which is compatible with 1000M / 100M rate, and the MAC part is completed by the signal processor kernel, so that the terminal can be used as a network device to realize the transmission and reception of Ethernet data, which is very suitable for use in extreme environments where network cables cannot be laid, real-time intercom, etc. such as disaster relief, last mile communication, etc. to realize networking or offline application with other communication devices.

[0062] The specific implementation functions of the signal processing unit are introduced as follows. The signal processing unit realizes adaptive gain of the signal by controlling the receiving end three-stage gain and the transmitting gain, and updates the binary threshold value to realize adaptive threshold. It should be noted that the signal processing unit can realize adaptive gain and adaptive threshold at the same time, or can realize only adaptive gain or adaptive threshold.

[0063] The embodiment of the application provides a wireless optical communication control method with adaptive communication distance, and the method comprises the steps of:

[0064] In step 11, the digital signals in the plurality of sampling periods are subjected to smoothing filtering to obtain filtered digital signals. Before the digital signals are subjected to smoothing filtering, the device is initialized, specifically: the signal processor initializes the transmitting power, the transimpedance amplification multiple, the first-stage gain, the second-stage gain, the communication rate, the voice sampling rate, etc. according to the default values. Here, the plurality of sampling periods can be 100.

[0065] Step 12, calculate the absolute value of the average value V1 of the high level data in the filtered digital signal; here, the high level data in 100 sampling periods is put into the high level array from high to low, and the low level data is put into the low level array from low to high.

[0066] Step 13, determine the size relationship between the absolute value and the binary threshold value, if the absolute value is greater than or equal to the binary threshold value, end the adjustment, otherwise, execute step 14; here, the binary threshold value can be greater than 1 / 3 of the range of the digital-to-analog converter ADC.

[0067] Step 14, determine the error Δ of the absolute value of the average value V1 and the binary threshold value;

[0068] Step 15, judge whether the error Δ is greater than 0, if not, perform the first level gain adjustment with ɑ * V DD / 2 N as the step value, ɑ is the step factor, V DD is the amplifier voltage value, and N is the number of digital potentiometer bits, if yes, perform the first level gain adjustment with -ɑ * V DD / 2 N as the step value, and sequentially increase until the maximum value; here, the acquisition method of ɑ can be: establishing a functional relationship between gain and control voltage, taking the minimum value of the derivative of the function as the value of ɑ, for example, ɑ can be 10, V DD = 3.3, N = 1024, and the calculated ɑ * V DD / 2 N = 30mv.

[0069] Step 16, calculate the absolute value of the average value V2 of the high level data in the filtered digital signal after gain adjustment, if the absolute value of the average value V2 is greater than or equal to the binary threshold value, end the adjustment, otherwise, return to step 11 and perform the next level gain adjustment.

[0070] Here, when entering the next level gain adjustment, i.e. the second level gain adjustment, steps 11-16 are executed, in the case of not meeting the corresponding condition (the absolute value of the average value V2 is greater than or equal to the binary threshold value), the third level gain adjustment is performed, and steps 11-16 are also executed, in the case of not meeting the corresponding condition (the absolute value of the average value V2 is greater than or equal to the binary threshold value), the fourth level gain adjustment is performed, here, the fourth level gain adjustment refers to the transmission gain adjustment, and steps 11-16 are also executed, in the case of not meeting the corresponding condition (the absolute value of the average value V2 is greater than or equal to the binary threshold value), the device is powered off.

[0071] Further, the method further comprises updating the binary threshold value, including:

[0072] Firstly, signal data greater than an initial binary threshold V0 in a plurality of sampling periods is set as logic "1", and the rest of the signal data is set as logic "0";

[0073] Then, the mean value V of the first set number P of logic "1" signal data is calculated hi , the mean value V of the second set number Q of logic "0" signal data is calculated, and the binary threshold is updated to V i =(V hi +V li ) / 2; here, the first set number P can be 100 bits, and the second set number Q can be 100 bits.

[0074] Finally, a sliding window is set, the sliding window length is ≤min(P, Q), the sliding window slides on the signal data of a plurality of sampling periods, and for each sliding of the sliding window, the updated binary threshold V j of the sliding window is calculated, including: calculating the mean value V hj and the standard deviation δ of the logic "1" signal data in the sliding window after each sliding ends, if V hj >V hi , the updated binary threshold V j =V i +δ, otherwise, V j =V i -δ.

[0075] It is worth noting that an updated binary threshold is calculated for the sliding window after each sliding ends, and the binary threshold corresponding to the sliding window is used for binary processing of the signal data in the sliding window.

[0076] Further, the method further comprises: performing binary processing on the signal data in the sliding window according to the updated binary threshold V j ; and performing error correction and decoding on the binary processed signal data to realize reception demodulation of the signal.

[0077] The above is a specific implementation of the signal processing unit only realizing adaptive gain, and simultaneously realizing adaptive gain and adaptive threshold.

[0078] In other embodiments, the signal processing unit can also only realize adaptive threshold, and the specific implementation process is as follows:

[0079] Step 21, performing smoothing filtering on the received digital signal in a plurality of sampling periods to obtain a filtered digital signal;

[0080] Step 22, setting the signal data greater than an initial binary threshold V0 in the filtered digital signal as logic "1", and setting the rest of the signal data as logic "0";

[0081] Step 23, calculating the mean value V of the first set number P of logical "1" signal data hi , calculating the mean value V of the second set number Q of logical "0" signal data li , updating the binary threshold value as V i =(V hi +V li ) / 2;

[0082] Step 24, setting a sliding window, the sliding window length ≤ min(P, Q), the sliding window slides for multiple sampling periods, for each sliding of the sliding window, calculating the updated binary threshold value V j of the sliding window, including: calculating the mean value V hj and the standard deviation δ of the logical "1" signal data in the sliding window after each sliding ends, if V hj >V hi , updating the binary threshold value V j =V i +δ, otherwise, V j =V i -δ.

[0083] Further, the signal processor is further configured to implement the following functions:

[0084] According to the updated binary threshold value V j , the signal data in the sliding window is binarized, and the binarized signal data is corrected and decoded to realize the receiving demodulation of the signal.

[0085] In summary, the present application solves the problem that the conventional laser communication device cannot adapt to the large dynamic range change of the received power. Through the "adaptive gain" and "adaptive threshold" methods on the portable terminal, the influence of the communication distance change, the alignment error and the atmospheric channel on the communication performance is overcome, the weight of the existing portable atmospheric laser communication terminal can be reduced to sub-kilogram level, handheld application is realized, the communication distance is improved from a few hundred meters to 5km, real-time optical communication and visible light telescopic "mobile communication" in the power change range of 80dB are realized, and the communication range of the portable atmospheric laser communication terminal is greatly improved.

[0086] The above merely describes various embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A portable wireless optical communication control method of communication distance adaptation, characterized by, The method comprises the following steps: Step 11, smoothing filtering the received digital signal in multiple sampling periods to obtain a filtered digital signal; Step 12, calculating the absolute value of the average value V1 of high-level data in the filtered digital signal; Step 13, determining the size relationship between the absolute value and the binarization threshold value, if the absolute value is greater than or equal to the binarization threshold value, ending the adjustment, otherwise, executing step 14; Step 14, determining the error of the absolute value of said average value V1 and said binarization threshold ; Step 15, judge if the error is greater than 0, if not, with a Step 15, judge if the error is greater than 0, if not, with a * V DD / 2 N Step 15, judge if the error is greater than 0, if not, with a DD Step 15, judge if the error is greater than 0, if not, with a * V DD / 2 N Step 15, judge if the error is greater than 0, if not, with a Step 16, calculating the absolute value of the average value V2 of high-level data in the filtered digital signal after gain adjustment, if the absolute value of the average value V2 is greater than or equal to the binarization threshold value, ending the adjustment, otherwise, returning to step 11 for next-stage gain adjustment; and sequentially repeating the above steps until completing four-stage gain adjustment. The method further comprises updating the binarization threshold value, comprising: setting signal data greater than an initial binary threshold value in a plurality of sampling periods to a logic "1" and the rest of the signal data to a logic "0" V 0 are set to a logic "1" and the rest of the signal data are set to a logic "0"; calculating a mean value of the signal data of a first set number P of logical "1" V hi calculating a mean value of the signal data of a second set number Q of logical "0" V li updating the binarization threshold to V i =(V hi +V li ) / 2; A sliding window is set, the length of the sliding window is less than or equal to min(P, Q), the sliding window slides on the signal data of multiple sampling periods, for each sliding of the sliding window, an updated binarization threshold corresponding to the sliding window is calculated V j , including: calculating the mean of the signal data of logical "1" in the sliding window after each sliding ends V hj , and the standard deviation δ, if V hj ＞V hi , the updated binarization threshold V j =V i + δ , otherwise, V j =V i - δ .

2. The method of claim 1, wherein, The method further comprises: According to the updated binarization threshold V j Binarizing the signal data within the sliding window; performing error correction and decoding on the signal data after binarization processing to realize receiving demodulation of the signal.

3. A portable wireless optical communication device with adaptive communication distance, characterized in that The method comprises the following steps: The telescope light machine body is used for realizing visible light telescoping, the optical communication unit is used for realizing emission and reception of infrared light beams, and the electronics unit is used for realizing emission power control of the infrared light beams and reception signal intensity control of the infrared light beams. The electronics unit comprises a signal processor, which is used for realizing the following functions: The signal processor is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The filtered digital signal is greater than the initial binary threshold V The signal data of 0 is set to logic "1", and the other signal data are set to logic "0"; calculating a mean value of the signal data of a first set number P of logical "1" V hi calculating a mean value of the signal data of a second set number Q of logical "0" V li updating the binarization threshold to V i =(V hi +V li ) / 2; A sliding window is set, the length of the sliding window is less than or equal to min(P, Q), the sliding window slides on the signal data of multiple sampling periods, for each sliding of the sliding window, an updated binary threshold corresponding to the sliding window is calculated V j , including: calculating the mean of the signal data of logical "1" in the sliding window after each sliding ends V hj , and the standard deviation δ, if V hj ＞V hi , the updated binary threshold V j =V i The signal processor is further used for realizing the following functions: , otherwise, V j =V i The signal processor is further used for realizing the following functions: .

4. The apparatus of claim 3, wherein, The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2.

5. The apparatus of claim 3, wherein, The signal processor is further used for realizing the following functions: According to the updated binarization threshold V j Binarizing the signal data within the sliding window; The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2.

6. The apparatus of claim 3, wherein, The signal processor is further used for realizing the following functions:

7. The apparatus of claim 3, wherein, The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2.

8. The apparatus of claim 3, wherein, The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims 1-2. 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The signal processor is further used for realizing the following functions: The electronics unit comprises a signal processor, which is used for realizing the communication distance adaptive portable wireless optical communication control method according to any one of claims

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