Underwater wireless optical communication receiving device and method based on multi-anode photomultiplier tube

Abstract

This invention relates to an underwater wireless optical communication receiving device and method based on a multi-anode photomultiplier tube. The device includes a signal receiving module, a photoelectric conversion module, a multi-channel transimpedance amplifier module, a signal decision and gain control module, and a signal processing module. The photoelectric conversion module includes a multi-anode photomultiplier tube and an attenuator array disposed on the cathode surface of the multi-anode photomultiplier tube. The attenuator array includes multiple optical attenuators with different transmittances. By adding an attenuator array to the front end of the multi-anode photomultiplier tube, the power of the transmitted optical signal varies as it passes through different positions of the attenuator array. This results in different power ranges corresponding to the output signals from different anodes, effectively increasing the overall power detection range of the receiving device. The device is simple in structure, low in complexity, and easy to promote and apply.

Description

Technical Field

[0001] This invention belongs to the field of underwater wireless communication technology, specifically relating to an underwater wireless optical communication receiving device and method based on a multi-anode photomultiplier tube. Background Technology

[0002] Underwater wireless communication technology is crucial for marine engineering applications. Whether it's transmitting seabed monitoring data back or exchanging information between underwater operating platforms, high-speed data transmission is essential. In recent years, underwater wireless optical communication using blue-green light as the information carrier has attracted widespread attention both domestically and internationally due to its outstanding advantages such as high transmission rate, low latency, light weight, and low power consumption. Combining this technology with underwater robotic platforms can solve engineering challenges such as in-situ data recovery from the seabed and has become an important development direction in the field of marine communications.

[0003] In practical applications, the link attenuation of wireless optical communication signals is affected by factors such as the optical characteristics of water and the communication distance. Therefore, the power of the optical signal reaching the receiver will vary under different operating environments. For communication optical signals with low power, the receiver needs sufficient sensitivity to achieve effective detection; however, when the power of the communication optical signal exceeds the rated operating range of the photodetector in the receiver, it can affect the accuracy of optical signal detection or even damage the photodetector. Therefore, underwater wireless optical communication receivers need to have a large optical power reception range.

[0004] In related technologies, to increase the received optical power range of underwater communication receivers, a variable attenuator is usually placed in front of the photodetector inside the receiver. The transmittance of the variable attenuator is adjusted to regulate the optical power reaching the photodetector, allowing the detector to operate at its optimal state. Commonly used variable attenuators include mechanical optical attenuators, MEMS optical attenuators, magneto-optical attenuators, thermo-optical attenuators, and liquid crystal attenuators (Ning Jie, "Research on Dynamic Control Technology in High-Speed ​​Blue-Green Laser Communication in Underwater"). However, the presence of a variable attenuator increases the size, weight, and complexity of the receiver, causing inconvenience in its use. Furthermore, the presence of a variable attenuator reduces the receiver's field of view to some extent, increasing the difficulty of aligning the transmitter and receiver during communication. Another method is to use detectors with internal gain, such as photomultiplier tubes, to receive optical signals. The power detection range is improved by adjusting the internal gain of the detector (Han Biao, Lu Zhenzhong, Lü Pei, et al., "Underwater Wireless Optical Communication Receiving Method and Device Based on Detector Internal Gain Control"). This method can improve the dynamic detection range of the receiver to some extent, but it cannot detect potential saturation problems on the detector's photosensitive surface. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides an underwater wireless optical communication receiving device and method based on a multi-anode photomultiplier tube. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] This invention provides an underwater wireless optical communication receiver based on a multi-anode photomultiplier tube, comprising:

[0007] The signal receiving module is used to receive communication optical signals;

[0008] A photoelectric conversion module is used to convert the communication optical signal into multiple communication current signals. The photoelectric conversion module includes a multi-anode photomultiplier tube and an attenuator array disposed on the cathode surface of the multi-anode photomultiplier tube. The attenuator array includes multiple optical attenuators with different transmittances.

[0009] A multi-channel transimpedance amplifier module is used to convert the multi-channel communication current signals into multi-channel communication voltage signals;

[0010] The signal decision and gain control module is used to compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment.

[0011] The signal processing module is used to decode the received communication signal to obtain communication data information.

[0012] In one embodiment of the present invention, the number of optical attenuators is the same as the number of anodes in the multi-anode photomultiplier tube.

[0013] In one embodiment of the present invention, the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times.

[0014] In one embodiment of the present invention, the number of channels of the multi-channel transimpedance amplifier module is the same as the number of anodes of the multi-anode photomultiplier tube, and the amplification factor of each channel is equal.

[0015] In one embodiment of the present invention, the signal decision and gain control module includes: a communication voltage signal analysis unit, a control signal generation unit, and a communication signal output unit, wherein,

[0016] The communication voltage signal analysis unit is used to compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver and determine the comparison result.

[0017] The control signal generation unit is used to generate a gain voltage control signal based on the comparison result to adjust the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0018] The communication signal output unit is used to determine the communication signal and output it based on the output result of the photoelectric conversion module after voltage multiplication adjustment.

[0019] In one embodiment of the present invention, when the signal amplitudes of the multiple communication voltage signals are all less than the operating range of the optical communication receiver, the control signal generation unit generates a first gain voltage control signal to increase the multiplication voltage of the multi-anode photomultiplier tube, so that only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver.

[0020] When the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the control signal generation unit generates a second gain voltage control signal to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0021] When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, the control signal generation unit does not generate a gain voltage control signal, thus maintaining the multiplication voltage of the current multi-anode photomultiplier tube unchanged.

[0022] In one embodiment of the present invention, when the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver, that communication voltage signal is output as a communication signal.

[0023] When the multiplication voltage of the multi-anode photomultiplier tube is at its minimum, and the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication signal output unit selects the communication voltage signal corresponding to the optical attenuator with the lowest transmittance as the communication signal output.

[0024] This invention provides an underwater wireless optical communication receiving method based on a multi-anode photomultiplier tube, comprising:

[0025] Step 1: Receive communication optical signals;

[0026] Step 2: Use an attenuator array to perform optical attenuation of the communication optical signal through multiple channels with different transmittances to obtain multiple communication optical signals with different optical attenuations;

[0027] Step 3: Use a multi-anode photomultiplier tube to convert the multiple communication optical signals with different optical attenuations to obtain multiple communication current signals;

[0028] Step 4: Convert the multi-channel communication current signal into a multi-channel communication voltage signal;

[0029] Step 5: Compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment.

[0030] Step 6: Decode the communication signal to obtain communication data information.

[0031] In one embodiment of the present invention, the attenuator array includes a plurality of optical attenuators with different transmittances; the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times; the number of optical attenuators is the same as the number of anodes in the multi-anode photomultiplier tube.

[0032] In one embodiment of the present invention, step 5 includes:

[0033] Step 5.1: Compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver;

[0034] Step 5.2: When the signal amplitudes of the multiple communication voltage signals are all less than the operating range of the optical communication receiver, a first gain voltage control signal is generated to increase the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0035] When the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, a second gain voltage control signal is generated to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0036] When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, no gain voltage control signal is generated, and the multiplication voltage of the current multi-anode photomultiplier tube remains unchanged.

[0037] Step 5.3: When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, that communication voltage signal is output as a communication signal.

[0038] When the multiplication voltage of the multi-anode photomultiplier tube is at its minimum, and the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication voltage signal corresponding to the optical attenuator with the lowest transmittance is selected as the communication signal output.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1. The underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube of the present invention adds an attenuator array to the front end of the multi-anode photomultiplier tube, so that the power of the transmitted optical signal is different when the communication optical signal passes through different positions of the attenuator array, so that the optical signal power range corresponding to the output signal of different anodes is different, which effectively increases the overall power detection range of the receiving device. The structure is simple, the complexity is low, and it is easy to promote and apply.

[0041] 2. The underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube of the present invention compares the output signals of different anodes of the multi-anode photomultiplier tube with the operating range of the optical communication receiver. Based on the comparison results, it monitors the optical signal power and device saturation state on the surface of the multi-anode photomultiplier tube, providing feedback for the adjustment of the gain within the multi-anode photomultiplier tube and reducing the probability of device damage.

[0042] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0043] Figure 1 This is a schematic diagram illustrating the working principle of a multi-anode photomultiplier tube provided in an embodiment of the present invention;

[0044] Figure 2 This is a structural block diagram of an underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube provided in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram illustrating the working process of an underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube provided in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of a simulation experimental device for an underwater wireless optical communication receiving method based on a multi-anode photomultiplier tube, provided in an embodiment of the present invention. Detailed Implementation

[0047] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, describes an underwater wireless optical communication receiving device and method based on a multi-anode photomultiplier tube according to the present invention.

[0048] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0049] Example 1

[0050] First, the working principle of the multi-anode photomultiplier tube and the design principle of this application will be explained. The multi-anode photomultiplier tube device can convert light signals into current signals. It is a high-sensitivity photodetector and can be used in underwater wireless optical communication receivers to convert the light signals received by the receiver into current signals.

[0051] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the working principle of a multi-anode photomultiplier tube provided in this embodiment of the invention. As shown in the figure, the multi-anode photomultiplier tube, as a special type of photomultiplier tube, mainly consists of a photoemitting cathode (cathode), a multi-channel electron multiplying dinter, and multiple electron collecting electrodes (anodes). When light shines on the cathode, the cathode excites photoelectrons into the vacuum. These photoelectrons enter the multiplication system under the influence of an external electric field, and are amplified by secondary emission at the dinter. Specifically, photoelectrons excited at different locations on the cathode are amplified by electron multiplying dinter through different channels, and then the amplified electrons are collected by different anodes as current signals for output. Therefore, the signal output by each anode is only related to the light signal of the corresponding photosensitive area on the cathode surface.

[0052] Based on this position-sensitive characteristic, if different optical attenuators are added to the photosensitive surface of a multi-anode photomultiplier tube according to the region, the linear operating range of optical power corresponding to each anode will be different, which effectively improves the overall linear operating range of the detector. Furthermore, by comparing the output current signals of different anodes, the optical signal power and device saturation state on the surface of the photodetector can be monitored, providing feedback for the adjustment of the gain within the photodetector.

[0053] For each detection channel consisting of a photocathode, a daradox channel, and an anode, when operating in the linear operating region, the current signal output from the anode is proportional to the optical signal power input to the cathode, and the proportionality coefficient is related to the DC voltage applied between the anode and cathode. The higher the DC voltage, the higher the proportionality coefficient, and the higher the detection sensitivity of the photomultiplier tube. Since the gain coefficients of all daradox channels in a multi-anode photomultiplier tube are approximately equal and controlled by the same DC voltage, the gain factor of the electrons can be changed by using the voltage applied between the anode and cathode of the photomultiplier tube as a control signal, thus adjusting the detection sensitivity of the device. The higher the voltage between the anode and cathode, the higher the detection sensitivity of the device. In communication, by changing the sensitivity of the photomultiplier tube, the detector can be adapted to different optical signal powers.

[0054] For different detection channels composed of photocathodes, dynode multiplier channels, and anodes, the linear operating region range of each detection channel varies depending on the optical transmittance of the attenuator added to the front end of the photocathode's photosensitive area. If the ratio between any two anode output signal amplitudes of a detection channel is approximately equal to the ratio of the optical transmittance of the corresponding attenuator added to the front end of the photocathode's photosensitive area, then the channel operates within the linear operating region; otherwise, saturation exists in the detection channel. This can be used as a basis to determine the detector's saturation operating state.

[0055] Please refer to the above. Figure 2 and Figure 3 , Figure 2 This is a structural block diagram of an underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the working process of an underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube provided in an embodiment of the present invention.

[0056] As shown in the figure, the underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube in this embodiment includes: a signal receiving module, a photoelectric conversion module, a multi-channel transimpedance amplifier module, a signal decision and gain control module, and a signal processing module.

[0057] The signal receiving module is used to receive communication optical signals. The photoelectric conversion module is used to convert the communication optical signals into multiple communication current signals.

[0058] In one alternative implementation, the receiving module can be a corresponding module in a current underwater communication receiver.

[0059] In one optional embodiment, the photoelectric conversion module includes: a multi-anode photomultiplier tube and an array of attenuators disposed on the cathode surface of the multi-anode photomultiplier tube, wherein the attenuator array includes multiple optical attenuators with different transmittances.

[0060] Optionally, the number of optical attenuators is the same as the number of anodes in the multi-anode photomultiplier tube, and the shape and size of each attenuator are consistent with the shape and size of the corresponding photosensitive surface of the cathode of the multi-anode photomultiplier tube. The optical attenuators are in close contact with the cathode surface of the multi-anode photomultiplier tube.

[0061] Optionally, the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times. For example, if the number of anodes in a multi-anode photomultiplier tube is 4, then optical attenuators with transmittances of 100%, 10%, 1%, and 0.1% are selected to form the attenuator array.

[0062] In this embodiment, the received communication optical signal is incident perpendicularly onto the attenuator array. After passing through the attenuator array, it is incident perpendicularly onto the cathode surface of the multi-anode photomultiplier tube, exciting photoelectrons. The multi-channel electron multiplier dynamo of the multi-anode photomultiplier tube amplifies these photoelectrons, and different electron multiplier dynamo channels can only amplify the signal in the corresponding area on the cathode surface. All electron multiplier dynamo channels have the same amplification factor. After being amplified by the multi-channel electron multiplier dynamo, the signals are output from the corresponding anodes of the multi-anode photomultiplier tube to obtain multiple communication current signals.

[0063] The multi-channel transimpedance amplifier module is used to convert multiple communication current signals into multiple communication voltage signals.

[0064] In one alternative implementation, the multi-channel transimpedance amplifier module consists of multiple independent channels of transimpedance amplifiers, the number of channels of the transimpedance amplifiers being the same as the number of anodes of the multi-anode photomultiplier tube, and the amplification factor of each channel being equal.

[0065] In this embodiment, the multi-anode photomultiplier tube outputs multiple communication current signals, which are respectively input to the corresponding multiple independent channels of the transimpedance amplifier in the multi-channel transimpedance amplifier module, converting the multiple communication current signals into multiple communication voltage signals.

[0066] The signal decision and gain control module is used to compare the signal amplitude of multiple communication voltage signals with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment.

[0067] In one optional implementation, the signal decision and gain control module includes: a communication voltage signal analysis unit, a control signal generation unit, and a communication signal output unit.

[0068] The communication voltage signal analysis unit is used to compare the signal amplitudes of multiple communication voltage signals with the operating range of the optical communication receiver and determine the comparison result; the control signal generation unit is used to generate a gain voltage control signal based on the comparison result to adjust the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver; the communication signal output unit is used to determine the communication signal and output it based on the output result of the photoelectric conversion module after the multiplication voltage adjustment.

[0069] The comparison results include the following situations: the signal amplitudes of all multiple communication voltage signals are less than the operating range of the optical communication receiver; the signal amplitudes of more than one of the multiple communication voltage signals are within the operating range of the optical communication receiver; and only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0070] Optionally, if the signal amplitudes of all multiple communication voltage signals are less than the operating range of the optical communication receiver, the multiplication voltage of the multi-anode photomultiplier tube is considered too low. In this case, the control signal generation unit generates a first gain voltage control signal to increase the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0071] When the amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the multiplication voltage of the multi-anode photomultiplier tube is considered to be too high. At this time, the control signal generation unit generates a second gain voltage control signal to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0072] When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, the control signal generation unit does not generate a gain voltage control signal, thus maintaining the current multiplication voltage of the multi-anode photomultiplier tube unchanged.

[0073] In an optional implementation, when the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication signal output unit outputs that communication voltage signal as a communication signal.

[0074] In an optional implementation, when the multiplication voltage of the multi-anode photomultiplier tube is reduced to its minimum value according to the second gain voltage control signal, more than one of the multiple communication voltage signals still has a signal amplitude within the operating range of the optical communication receiver. At this time, the communication signal output unit selects the communication voltage signal corresponding to the optical attenuator with the lowest transmittance as the communication signal output. Simultaneously, the minimum value of the multiplication voltage of the multi-anode photomultiplier tube is kept constant.

[0075] In this embodiment, the communication voltage signal corresponding to the optical attenuator with the lowest transmittance is selected, that is, the communication voltage signal output by the channel with the lowest sensitivity is selected as the communication signal.

[0076] Optionally, the signal decision and gain control module can be built using an FPGA (Field-Programmable Gate Array) and its peripheral hardware circuits, as long as the above functions are implemented, and the specific circuit is not limited.

[0077] The signal processing module is used to decode the received communication signals to obtain communication data information.

[0078] In an optional implementation, the signal processing module can be a corresponding module in a current underwater communication receiver. It mainly uses equalization and filtering methods to shape and process the communication voltage signal. Finally, through clock extraction, decision circuit and decoding circuit, the information of the transmitting end is recovered to obtain the communication data information.

[0079] This embodiment of the underwater wireless optical communication receiver based on a multi-anode photomultiplier tube (MPT) incorporates an attenuator array at the front end of the MPT. This allows the transmitted optical signal power to vary at different positions within the attenuator array, resulting in different power ranges corresponding to the output signals of different anodes. This effectively increases the overall power detection range of the receiver. The device is simple in structure, low in complexity, and easy to promote and apply. Furthermore, by comparing the output signals of different anodes of the MPT with the operating range of the optical communication receiver, the optical signal power and saturation state of the MPT surface can be monitored based on the comparison results. This provides feedback for adjusting the gain within the MPT, reducing the probability of device damage.

[0080] Example 2

[0081] This embodiment provides an underwater wireless optical communication receiving method based on a multi-anode photomultiplier tube, applicable to the underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube described in the above embodiment. The method includes:

[0082] Step 1: Receive communication optical signals;

[0083] Step 2: Use an attenuator array to perform optical attenuation of the communication optical signal through multiple channels with different transmittances to obtain multiple communication optical signals with different optical attenuations;

[0084] Step 3: Use a multi-anode photomultiplier tube to convert the multiple communication optical signals with different optical attenuations to obtain multiple communication current signals;

[0085] In this embodiment, the attenuator array includes multiple optical attenuators with different transmittances; the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times; the number of optical attenuators is the same as the number of anodes in a multi-anode photomultiplier tube.

[0086] Step 4: Convert the multi-channel communication current signal into a multi-channel communication voltage signal;

[0087] Step 5: Compare the signal amplitudes of the multiple communication voltage signals with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment.

[0088] In an optional implementation, step 5 includes:

[0089] Step 5.1: Compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver;

[0090] Step 5.2: When the signal amplitudes of the multiple communication voltage signals are all less than the operating range of the optical communication receiver, a first gain voltage control signal is generated to increase the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0091] When the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, a second gain voltage control signal is generated to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver.

[0092] When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, no gain voltage control signal is generated, and the multiplication voltage of the current multi-anode photomultiplier tube remains unchanged.

[0093] Step 5.3: When the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver, output that communication voltage signal as a communication signal.

[0094] When the multiplication voltage of the multi-anode photomultiplier tube is at its minimum, and the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication voltage signal corresponding to the optical attenuator with the lowest transmittance is selected as the communication signal output.

[0095] Step 6: Decode the communication signal to obtain the communication data information.

[0096] Example 3

[0097] The effectiveness of the underwater wireless optical communication receiving device and method based on multi-anode photomultiplier tubes of the present invention is illustrated by simulation experiments.

[0098] Please see Figure 4 The diagram shown is a schematic of a simulation experimental device for an underwater wireless optical communication receiving method based on a multi-anode photomultiplier tube, provided by an embodiment of the present invention.

[0099] First, a pseudo-random binary sequence (PRBS) is generated using a bit error rate analyzer to simulate communication data. This PRBS sequence is then used to control the optical signal output by the blue-green optical communication transmitter. The modulation format of the optical signal is on-off keying (OOK): when the PRBS sequence is logic "1", the communication transmitter outputs an optical signal; when the PRBS sequence is logic "0", the communication transmitter does not output an optical signal. Therefore, the presence or absence of an optical signal can be used to characterize the communication data. In this embodiment, the light source used is a laser diode with a center wavelength of 450nm in the blue light band. The electrical signal output by the bit error rate analyzer is converted into an optical signal through direct modulation. This optical signal serves as the communication optical signal that the optical communication receiver needs to receive.

[0100] Then, the communication optical signal passes through a water tank and an adjustable attenuator before reaching the optical communication receiver. The water tank simulates the transmission of light in water, and the adjustable attenuator simulates the power variation of the optical signal arriving at the optical communication receiver.

[0101] Finally, the optical communication receiver is used to perform photoelectric detection on the communication optical signal. The decision circuit is used to recover the original communication data information, namely logic "1" and logic "0", from the voltage signal after photoelectric conversion. Then, the bit error rate of the communication system is tested by comparing the received logic data with the transmitted logic data one by one using a bit error rate meter.

[0102] The optical communication receiver adopts the underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube as described in the embodiments of the present invention.

[0103] In this embodiment, the attenuator array is composed of four attenuators with optical transmittances of 100%, 10%, 1%, and 0.1%, respectively; the multi-anode photomultiplier tube has four daradox channels and corresponding anodes, and the front ends of the photocathode photosensitive areas corresponding to channels 1, 2, 3, and 4 are covered and closely attached to the four attenuators with optical transmittances of 100%, 10%, 1%, and 0.1%, respectively; the multi-channel transimpedance amplifier has four channels, and the amplification factor of each channel is equal.

[0104] In the specific experiment, the signal rate of the bit error rate tester was set to 20Mbps, and the amplitude of the transimpedance amplifier output signal was set to 0.8V to 1.5V, which is the rated operating range of the optical communication receiver. When only one signal amplitude in the multi-channel transimpedance amplifier falls within this range, this signal is output as the communication signal, and the DC control voltage output remains unchanged. When the amplitude of all voltage signals is less than 0.8V, the multiplication voltage inside the multi-anode photomultiplier tube is considered too low. In this case, the output DC control voltage is increased until at least one signal amplitude falls within the 0.8V to 1.5V range, and this signal is output as the communication signal. When at least two signals amplitudes fall within the 0.8V to 1.5V range, the multiplication voltage inside the multi-anode photomultiplier tube is considered too high. In this case, the output DC control voltage is decreased until only one signal amplitude falls within the 0.8V to 1.5V range, and this signal is output as the communication signal. When the DC control voltage is at its minimum value, and at least two signals still fall within the amplitude range required for normal communication, the DC control voltage is kept at its minimum, and the output signal of the channel corresponding to the least sensitive voltage signal (i.e., the channel with the smallest attenuator) within the operating range is taken as the communication signal.

[0105] The optical power reaching the optical communication receiver is controlled by a variable attenuator, and the DC voltage output by the gain control module is set according to the amplitude output of the 4-channel transimpedance amplifier module. The saturation value of the transimpedance amplifier output signal amplitude is 1.5V, and the minimum resolvable voltage amplitude is 0.01V. The minimum operating voltage applied between the cathode and anode of the multi-anode photomultiplier tube is 300V. The bit error rate was statistically analyzed in 1-minute intervals. After extensive testing, the results are shown in Table 1.

[0106] Table 1. Simulation Experiment Test Results

[0107]

[0108] As can be seen from the table, the multi-anode photomultiplier tube enables the optical communication receiver to adapt to different optical powers, allowing it to adapt to optical signal power variations in the range of 0.05μW to 5mW.

[0109] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0110] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A multi-anode photomultiplier tube based underwater wireless optical communication receiving device, characterized by, include: The signal receiving module is used to receive communication optical signals; A photoelectric conversion module is used to convert the communication optical signal into multiple communication current signals. The photoelectric conversion module includes a multi-anode photomultiplier tube and an attenuator array disposed on the cathode surface of the multi-anode photomultiplier tube. The attenuator array includes multiple optical attenuators with different transmittances. A multi-channel transimpedance amplifier module is used to convert the multi-channel communication current signals into multi-channel communication voltage signals; The signal decision and gain control module is used to compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment. The signal processing module is used to decode the received communication signal to obtain communication data information; The number of optical attenuators is the same as the number of anodes in the multi-anode photomultiplier tube; the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times; the number of channels in the multi-channel transimpedance amplifier module is the same as the number of anodes in the multi-anode photomultiplier tube, and the amplification factor of each channel is equal.

2. The multi-anode photomultiplier tube based underwater wireless optical communication receiving apparatus according to claim 1, characterized by The signal decision and gain control module includes: a communication voltage signal analysis unit, a control signal generation unit, and a communication signal output unit, wherein... The communication voltage signal analysis unit is used to compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver and determine the comparison result. The control signal generation unit is used to generate a gain voltage control signal based on the comparison result to adjust the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver. The communication signal output unit is used to determine the communication signal and output it based on the output result of the photoelectric conversion module after voltage multiplication adjustment.

3. The underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube according to claim 2, characterized in that, When the signal amplitudes of the multiple communication voltage signals are all less than the operating range of the optical communication receiver, the control signal generation unit generates a first gain voltage control signal to increase the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver. When the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the control signal generation unit generates a second gain voltage control signal to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver. When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, the control signal generation unit does not generate a gain voltage control signal, thus maintaining the multiplication voltage of the current multi-anode photomultiplier tube unchanged.

4. The underwater wireless optical communication receiving device based on a multi-anode photomultiplier tube according to claim 3, characterized in that, When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, that communication voltage signal is output as a communication signal. When the multiplication voltage of the multi-anode photomultiplier tube is at its minimum, and the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication signal output unit selects the communication voltage signal corresponding to the optical attenuator with the lowest transmittance as the communication signal output.

5. A method for receiving an underwater wireless optical communication based on a multi-anode photomultiplier tube, characterized in that, include: Step 1: Receive communication optical signals; Step 2: Use an attenuator array to perform optical attenuation of the communication optical signal through multiple channels with different transmittances to obtain multiple communication optical signals with different optical attenuations; Step 3: Use a multi-anode photomultiplier tube to convert the multiple communication optical signals with different optical attenuations to obtain multiple communication current signals; Step 4: Convert the multi-channel communication current signal into a multi-channel communication voltage signal; Step 5: Compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver, generate a gain voltage control signal based on the comparison result, adjust the multiplication voltage of the multi-anode photomultiplier tube, and determine the output of one communication signal based on the output result of the photoelectric conversion module after the multiplication voltage adjustment. Step 6: Decode the communication signal to obtain communication data information; the attenuator array includes multiple optical attenuators with different transmittances; the transmittance difference between two adjacent optical attenuators in the attenuator array is not less than 10 times; The number of optical attenuators is the same as the number of anodes in the multi-anode photomultiplier tube; Step 5 includes: Step 5.1: Compare the signal amplitude of the multi-channel communication voltage signal with the operating range of the optical communication receiver; Step 5.2: When the signal amplitudes of the multiple communication voltage signals are all less than the operating range of the optical communication receiver, a first gain voltage control signal is generated to increase the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver. When the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, a second gain voltage control signal is generated to reduce the multiplication voltage of the multi-anode photomultiplier tube, so that the signal amplitude of only one of the multiple communication voltage signals is within the operating range of the optical communication receiver. When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, no gain voltage control signal is generated, and the multiplication voltage of the current multi-anode photomultiplier tube remains unchanged. Step 5.3: When only one of the multiple communication voltage signals has a signal amplitude within the operating range of the optical communication receiver, that communication voltage signal is output as a communication signal. When the multiplication voltage of the multi-anode photomultiplier tube is at its minimum, and the signal amplitude of more than one of the multiple communication voltage signals is within the operating range of the optical communication receiver, the communication voltage signal corresponding to the optical attenuator with the lowest transmittance is selected as the communication signal output.

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