A communication receiving apparatus and system

Abstract

The application discloses a kind of communication receiving device and system, it is related to communication field, including signal receiving module, single photon detector, filter, processing module, the cut-off frequency of filter is proportional to the communication rate of communication receiving device, when the communication rate of communication receiving device changes, the cut-off frequency of filter also changes with the change of communication rate, while filter will the pulse sequence of single photon detector output is shaped as level signal, processing module can utilize level signal quickly and simply to restore communication data, greatly simplify the algorithm difficulty of data recovery, to solve the problem of data recovery under the premise of variable communication rate, while guaranteeing the flexibility of communication receiving device, information extraction and data recovery are realized, and additional clock signal does not need to be increased to set, structure is relatively simple, and complexity is low, convenient for popularization and application, expand the application range of communication receiving device.

Description

Technical Field

[0001] This invention relates to the field of communications, and in particular to a communication receiving device and system. Background Technology

[0002] In recent years, underwater wireless communication technology 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. Underwater wireless communication technology is crucial for applications in fields such as marine engineering. In particular, combining communication devices utilizing this technology with underwater robotic platforms can solve marine engineering challenges such as in-situ data recovery from the seabed and close-range information exchange between underwater mobile platforms. Therefore, the development of underwater wireless optical communication technology has become an important direction for the marine communication field. In practical applications, improving the transmission distance of the communication system is one of the key technical challenges that needs to be addressed. The current solution is to use photon counting detection to improve the sensitivity of the receiver, thereby increasing the overall transmission distance of the communication system. Photon counting detection typically uses photomultiplier tubes (PMTs) or avalanche photodiodes (APDs) as single-photon detection devices. PMTs are vacuum devices with the advantage of a large photosensitive surface, but they are also large in size, have high multiplication voltage, and are susceptible to electromagnetic interference. In contrast, Avalanche photodiodes are semiconductor photodetectors with advantages such as small size, low multiplication voltage, and strong resistance to electromagnetic interference. However, when using avalanche photodiodes for photon counting communication, a quenching circuit is usually added to the device to suppress afterpulses. This results in the output signal of the device usually appearing in the form of a pulse sequence, which makes it difficult to recover the subsequent communication data. How to solve the problem of data recovery is an urgent issue to be addressed.

[0003] In existing technologies, two solutions exist to address the data recovery challenge in underwater photon counting detection communication. The first method sets the communication rate to match the counting rate of the single-photon detector. In this case, each output pulse of the single-photon detector represents one bit of information. This method can solve the information extraction and data recovery problem to some extent, but the communication rate is relatively fixed, resulting in low flexibility and making it unsuitable for various situations. The second method uses a bit time as a time window, counts the number of pulses within each time window, and then sets a pulse count threshold for judgment to identify the original data. However, this method requires additional clock information to determine the start position of each bit time, increasing the difficulty of engineering implementation. Summary of the Invention

[0004] The purpose of this invention is to provide a communication receiving device and system that greatly simplifies the algorithmic difficulty of data recovery and solves the problem of data recovery under the premise of variable communication rate. While ensuring the flexibility of the communication receiving device, it realizes information extraction and data recovery, and does not require the addition of an extra clock signal. The structure is relatively simple and has low complexity, making it easy to promote and apply, and expanding the application range of communication receiving devices.

[0005] To solve the above-mentioned technical problems, the present invention provides a communication receiving device, including a signal receiving module, a single-photon detector, a filter, and a processing module; the output terminal of the signal receiving module is connected to the input terminal of the single-photon detector, the output terminal of the single-photon detector is connected to the input terminal of the filter, and the output terminal of the filter is connected to the input terminal of the processing module.

[0006] The single-photon detector is used to convert the optical signal received by the signal receiving module into a pulse sequence;

[0007] The filter is used to shape the pulse sequence output by the single-photon detector into a level signal output;

[0008] The processing module is used to obtain communication data based on the level signal; the cutoff frequency of the filter is proportional to the communication rate of the communication receiving device.

[0009] Preferably, the processing module is further used for,

[0010] Obtain the communication rate of the communication receiving device;

[0011] The target cutoff frequency of the filter is obtained by multiplying the communication rate by a preset factor.

[0012] The cutoff frequency of the filter is adjusted to the target cutoff frequency.

[0013] Preferably, when the filter is an RC filter, adjusting the cutoff frequency of the filter to the target cutoff frequency includes:

[0014] Adjust the values ​​of the resistors and / or capacitors in the filter to adjust the cutoff frequency of the filter to the target cutoff frequency.

[0015] Preferably, the filter is a low-pass filter, and the cutoff frequency of the low-pass filter is less than the frequency of the pulse sequence.

[0016] Preferably, the single-photon detector is an avalanche photodiode.

[0017] Preferably, the processing module is a voltage comparator, and the input terminal of the voltage comparator is connected to the output terminal of the filter;

[0018] The voltage comparator outputs logic 1 when the level signal is greater than a preset threshold and outputs logic 0 when the level signal is less than the preset threshold.

[0019] To address the aforementioned technical problems, the present invention also provides a communication system, including a communication transmitting device and a communication receiving device as described above, wherein the communication transmitting device and the communication receiving device are connected.

[0020] Preferably, it further includes a variable attenuator, the input of which is connected to the output of the communication transmitting device, and the output of which is connected to the communication receiving device;

[0021] The variable attenuator is used to adjust the power of the received optical signal output by the communication transmitting device so that the communication receiving device can receive the optical signal.

[0022] This invention provides a communication receiving device, including a signal receiving module, a single-photon detector, a filter, and a processing module. The cutoff frequency of the filter is proportional to the communication rate of the receiving device. When the communication rate changes, the cutoff frequency of the filter also changes accordingly. Simultaneously, the filter shapes the pulse sequence output by the single-photon detector into a level signal. The processing module can quickly and easily recover the communication data using this level signal, greatly simplifying the algorithm for data recovery. This solves the data recovery problem even with variable communication rates. While ensuring the flexibility of the receiving device, it achieves information extraction and data recovery without requiring an additional clock signal. The structure is relatively simple and low in complexity, making it easy to promote and apply, thus expanding the application range of communication receiving devices.

[0023] The present invention also provides a communication system that has the same beneficial effects as the communication receiving device described above. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the structure of a communication receiving device provided by the present invention;

[0026] Figure 2 An application block diagram of a communication receiving device provided by the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of a communication receiving device during a simulation experiment provided by the present invention;

[0028] Figure 4 A schematic diagram of a signal waveform of a communication receiving device provided by the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of a communication system provided by the present invention. Detailed Implementation

[0030] The core of this invention is to provide a communication receiving device and system that greatly simplifies the algorithmic difficulty of data recovery and solves the problem of data recovery under the premise of variable communication rate. While ensuring the flexibility of the communication receiving device, it realizes information extraction and data recovery, and does not require the addition of an extra clock signal. The structure is relatively simple and has low complexity, making it easy to promote and apply, and expanding the application range of communication receiving devices.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a communication receiving device provided by the present invention; please refer to... Figure 2 , Figure 2 This invention provides an application block diagram of a communication receiving device. To solve the above-mentioned technical problems, this invention provides a communication receiving device 22, including a signal receiving module 1, a single-photon detector 2, a filter 3, and a processing module 4. The output terminal of the signal receiving module 1 is connected to the input terminal of the single-photon detector 2, the output terminal of the single-photon detector 2 is connected to the input terminal of the filter 3, and the output terminal of the filter 3 is connected to the input terminal of the processing module 4.

[0033] The single-photon detector 2 is used to convert the optical signal received by the signal receiving module 1 into a pulse sequence;

[0034] Filter 3 is used to shape the pulse sequence output by single-photon detector 2 into a level signal output;

[0035] The processing module 4 is used to obtain communication data based on the level signal; the cutoff frequency of the filter 3 is proportional to the communication rate of the communication receiving device 22.

[0036] Specifically, after receiving the optical signal, the signal receiving module 1 transmits the optical signal to the single-photon detector 2. The single-photon detector 2 converts the received optical signal into discrete voltage pulses, that is, a pulse sequence signal, and outputs it to the filter 3. Then, the filter 3 converts the pulse sequence signal into a level signal. After receiving the level signal output by the filter 3, the processing module 4 can use the level signal to recover the communication data.

[0037] It is easy to understand that signal receiving module 1 is used to collect optical signals for communication, and is usually implemented by an optical receiving module; single-photon detector 2 is a device that can convert optical signals into electrical signals by photon counting detection, and can be implemented by devices such as avalanche photodiodes or photomultiplier tubes; filter 3 is mainly used to shape the voltage pulse sequence output by single-photon detector 2, so that it is output in a high-level or low-level manner, so that processing module 4 can recover data according to the level signal; processing module 4 is used to decode the output signal of filter 3 to recover the original communication data information. This application does not make any special limitations on the specific types and implementation methods of signal receiving module 1, photoelectron detector, filter 3, and processing module 4.

[0038] Considering that the communication rate may vary depending on the application scenario, the cutoff frequency of filter 3 in this application is proportional to the communication rate of communication receiving device 22. When the communication rate of communication receiving device 22 changes, the cutoff frequency of filter 3 will also be readjusted accordingly. That is, filter 3 in this application is an adjustable filter, and its cutoff frequency is proportional to the communication rate. This allows filter 3 to more accurately convert the pulse sequence into the corresponding level signal during the processing of the pulse sequence, improving the accuracy of the conversion process, improving the accuracy of data recovery by processing module 4, and further reducing the difficulty of data recovery. The communication receiving device 22 provided in this application solves the problem of receiving signal processing and data recovery in the process of variable-rate underwater photon counting communication without the need for an external clock.

[0039] It is understood that the communication rate of the communication receiving device 22 is also the communication rate of the entire communication system. The communication rate of the communication system is determined by the transmitter and receiver of the communication system, and is related to the device's own parameters, application environment and specific application requirements. This application does not make any special limitations here.

[0040] This invention provides a communication receiving device 22, including a signal receiving module 1, a single-photon detector 2, a filter 3, and a processing module 4. The cutoff frequency of the filter 3 is proportional to the communication rate of the communication receiving device 22. When the communication rate of the communication receiving device 22 changes, the cutoff frequency of the filter 3 also changes accordingly. Simultaneously, the filter 3 shapes the pulse sequence output by the single-photon detector 2 into a level signal. The processing module 4 can quickly and easily recover the communication data using the level signal, greatly simplifying the algorithm difficulty of data recovery. Thus, it solves the problem of data recovery under the premise of variable communication rate. While ensuring the flexibility of the communication receiving device 22, it realizes information extraction and data recovery without the need to add an additional clock signal. The structure is relatively simple, with low complexity, making it easy to promote and apply, and expanding the application range of the communication receiving device 22.

[0041] Based on the above embodiments,

[0042] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the communication receiving device provided by the present invention during a simulation experiment; please refer to... Figure 4 , Figure 4 A schematic diagram of a signal waveform of a communication receiving device provided by the present invention; Figure 4 Waveform diagram ① is a schematic diagram of the level signal output by filter 3, and waveform diagram ② is a schematic diagram of the pulse sequence signal output by single-photon detector 2.

[0043] In a preferred embodiment, processing module 4 is further used to,

[0044] Obtain the communication rate of the communication receiving device 22;

[0045] Multiplying the communication rate by a preset factor yields the target cutoff frequency of filter 3;

[0046] Adjust the cutoff frequency of filter 3 to the target cutoff frequency.

[0047] Considering that the cutoff frequency of filter 3 needs to change with the communication rate, a preset multiple can be set in advance. The target cutoff frequency of filter 3 is obtained by multiplying the communication rate by the preset multiple, thus ensuring that the cutoff frequency of filter 3 changes proportionally with the communication rate. For example, the cutoff frequency of filter 3 can be set to twice the communication rate. This application does not impose any special limitations on the specific value and setting method of the preset multiple; it can be selected according to the actual application circuit and application requirements. The preset multiple can be set in advance in the processing module 4. When the communication rate changes, the processing module 4 directly calculates the target cutoff frequency and controls the filter 3 to adjust its cutoff frequency. Alternatively, the preset multiple can be set through manual calculation and manual adjustment of filter 3. This application does not impose any special limitations on the specific adjustment method of the cutoff frequency of filter 3.

[0048] Specifically, a preset multiple is set in advance, and the cutoff frequency of filter 3 is adjusted based on the communication rate and the preset multiple, so that the cutoff frequency of filter 3 changes with the communication rate. The adjustable filter 3 realizes the data recovery process of the variable rate communication system, which is convenient for promotion and application, expands the application range of communication receiving device 22, and further expands the application range of the entire communication system.

[0049] In a preferred embodiment, when filter 3 is an RC filter, adjusting the cutoff frequency of filter 3 to the target cutoff frequency includes:

[0050] Adjust the values ​​of the resistors and / or capacitors in filter 3 to adjust the cutoff frequency of filter 3 to the target cutoff frequency.

[0051] It is not difficult to understand that there are multiple ways to implement filter 3. When filter 3 is an RC filter, the process of adjusting the cutoff frequency of filter 3 can be achieved by adjusting the values ​​of the resistor and / or capacitor in the RC filter. This application does not make any special restrictions on the specific adjustment process and adjustment parameters, etc., and the selection can be made according to the actual application circuit and application requirements.

[0052] Specifically, filter 3 can be an RC filter. When filter 3 is an RC filter, the adjustment of the cutoff frequency of filter 3 can be achieved by the values ​​of the resistor and / or capacitor in the RC filter. It is easy to implement and simple to operate. The circuit structure of the entire filter 3 is simple, small in size and low in cost. It effectively realizes the function of filter 3, reduces the cost of the entire communication receiving device 22, reduces the size, facilitates promotion and application, and expands the application range of communication receiving device 22.

[0053] In a preferred embodiment, filter 3 is a low-pass filter, and the cutoff frequency of the low-pass filter is less than the frequency of the pulse sequence.

[0054] It is understandable that filter 3 can be a low-pass filter, a high-pass filter, or a band-pass filter. When filter 3 is a low-pass filter, in order to accurately convert the pulse sequence signal into a level signal corresponding to the communication data, the cutoff frequency of the low-pass filter needs to be set to be lower than the frequency of the pulse sequence. Only when the cutoff frequency is lower than the frequency of a single pulse can the discrete pulses output by the single-photon detector 2 be shaped into the required level signal, and the processing module 4 can then recover a relatively correct communication data based on the obtained level signal. Please refer to... Figure 4 Only when the cutoff frequency is less than the frequency of a single pulse can it be... Figure 4 The pulse sequence shown in waveform ② is shaped as follows: Figure 4 The effect is shown in waveform diagram ①. This application does not specifically limit the specific type and implementation of the low-pass filter. It is easy to understand that when filter 3 is a high-pass filter, the cutoff frequency of the high-pass filter needs to be set to be greater than the frequency of the pulse sequence.

[0055] Specifically, when a low-pass filter is selected for filter 3, the cutoff frequency of the low-pass filter needs to be set to be less than the frequency of the pulse sequence so that filter 3 can shape the pulse sequence into a more accurate level signal, ensuring the accuracy of data recovery by processing module 4 and improving the accuracy and reliability of communication receiving device 22.

[0056] In one preferred embodiment, the single-photon detector 2 is an avalanche photodiode.

[0057] Specifically, the photoelectric detector can be an avalanche photodiode, and when the avalanche photodiode operates during photon counting, it typically employs Geiger mode, which enables detection sensitivity at the single-photon level. This application does not impose any specific limitations on the specific signals and parameters of the avalanche photodiode.

[0058] As a specific embodiment, selecting an avalanche photodiode operating in Geiger mode as the single-photon detector 2 can reduce costs, improve quantum efficiency, ensure detection sensitivity during communication, is easy to implement, has a simple circuit structure, is easy to promote and apply, and expands the application range of the communication receiving device 22.

[0059] In a preferred embodiment, when a bit error rate meter is used to control the optical signal output, the processing module 4 is further used to:

[0060] The level signal is compared with the control signal output by the bit error rate meter to obtain the bit error rate of the communication receiving device 22.

[0061] Before practical application, it is necessary to perform bit error rate testing on the communication receiving device 22 to ensure that the communication receiving device 22 can achieve data communication and recovery within the allowable error range. During the testing phase, a bit error rate tester can be used to simulate the communication data information. After the communication receiving device 22 has completed the reception and recovery of data, the data recovered by the processing module 4 is compared with the control signal initially output by the bit error rate tester to determine the bit error rate of the communication receiving device 22.

[0062] It should be noted that during the testing process, a communication transmitter is required to simulate the entire communication process. The control signal output by the bit error rate tester is also a control signal for the communication transmitter. After receiving the control signal from the bit error rate tester, the communication transmitter will output a preset optical signal according to the control signal of the bit error rate tester. The electrical signal output by the bit error rate tester can be converted into an optical signal through direct modulation. This optical signal serves as the communication optical signal that the communication receiving device 22 needs to receive, so that the processing module 4 in the communication receiving device 22 can recover the data corresponding to the control signal of the bit error rate tester. At the same time, in order to simulate the underwater communication environment, a water tank or other type of container can be directly set up between the communication transmitter and the communication receiving device 22 to simulate the transmission process of light in water, so as to ensure the accuracy of the test process.

[0063] In one specific embodiment, the communication receiving device 22 is configured as an optical communication receiver. When the processing module 4 is implemented through a decision circuit, the optical communication receiver performs photoelectric detection on the communication optical signal, and uses the decision circuit to recover the original communication data information, i.e., logic "1" and logic "0", from the voltage signal after photoelectric conversion. Then, the received logic data and the transmitted logic data are compared one by one using a bit error rate tester to test the bit error rate of the communication system. In a specific experiment, the signal rate output by the bit error rate tester can be set to 4 Mbps.

[0064] Specifically, this application does not impose any particular limitations on the specific types and implementation methods of the bit error rate tester, communication transmitter, and water tank, nor on the signal rate or other parameters output by the bit error rate tester. The implementation methods of the control signal output by the bit error rate tester and the optical signal output by the communication transmitter also vary, and can include blue-green light or other optical signals; this application does not impose any particular limitations on these methods. The process of obtaining the bit error rate can be directly implemented using processing module 4, or it can be obtained through other control systems or manual calculation; this application does not impose any particular limitations on these methods.

[0065] Specifically, a simulation experiment of the actual application process of the communication receiving device 22 is carried out using devices such as a bit error rate tester, and a principle demonstration system is built to verify whether the data reception and recovery function of the communication receiving device 22 is accurate. At the same time, it can also verify whether the data reception and recovery of the communication receiving device 22 is effective for the adjustable rate communication process, ensuring the accurate implementation of the actual application process of the communication receiving device 22 and guaranteeing the accuracy and reliability of the communication receiving device 22.

[0066] In a preferred embodiment, the control signal output by the bit error rate tester is a PRBS sequence.

[0067] It's easy to understand that the control signal output by the bit error rate tester can be implemented using a PRBS (Pseudo-Random Binary Sequence) sequence. This PRBS sequence, generated by the tester, simulates communication data and controls the optical signal output by the communication transmitter. The modulation format of the optical signal from the transmitter is OOK (On-Off Keying); when the PRBS sequence is logic "1", the transmitter outputs an optical signal; when the PRBS sequence is logic "0", the transmitter does not output an optical signal. Therefore, the presence or absence of an optical signal can characterize the communication data. The light source used in the simulation can be a laser diode with a center wavelength of 450nm.

[0068] As a specific embodiment, the control signal output by the bit error rate tester can be implemented using a PRBS sequence, which has randomness and periodicity. It can effectively simulate the actual data stream, ensuring the accuracy and reliability of the testing process of the communication receiving device 22, and is conducive to the accurate implementation of the communication receiving device 22.

[0069] In a preferred embodiment, the processing module 4 is a voltage comparator, and the input terminal of the voltage comparator is connected to the output terminal of the filter 3;

[0070] The voltage comparator outputs logic 1 when the voltage level signal is greater than a preset threshold and logic 0 when the voltage level signal is less than the preset threshold.

[0071] It is understood that there are many ways for the processing module 4 to recover the level signal into communication data. It can be implemented directly using a voltage comparator, or it can be implemented using other types of decision circuits and / or logic circuits. When the processing module 4 is implemented using a voltage comparator, a preset threshold needs to be set in advance as the reference for judging the level signal. The preset threshold can be set to half the amplitude of the output signal. This application does not make any special restrictions on the specific value and setting method of the preset threshold. This application does not make any special restrictions on the specific type and implementation method of the voltage comparator.

[0072] Specifically, selecting a voltage comparator as the processing module 4 can effectively realize the function of the processing module 4. It has a simple structure, is easy to implement, and is easy to promote and apply, thus expanding the application scope of the communication receiving device 22.

[0073] As a specific embodiment, such as Figure 3 As shown, the specific steps of the simulation experiment of the communication receiving device 22 are as follows.

[0074] Step 1: Signal receiving module 1 receives the communication optical signal passing through the water tank and variable attenuator. At this time, the optical signal meets the rated optical power range of single-photon detector 2. Step 2: Using a Geiger-mode avalanche photodiode as single-photon detector 2, the optical signal is detected, and the photoelectric converted signal is output as a voltage pulse sequence. Step 3: A low-pass filter is used to shape the pulse sequence output by the avalanche photodiode, making it output as a high or low level. The selected low-pass filter has a cutoff frequency of 8MHz. Step 4: Processing module 4 uses a voltage comparator with a threshold equal to half the amplitude of the output signal to recover the original communication data information from the photoelectric converted voltage signal.

[0075] In this embodiment, the signals output by the single-photon detector 2 and the low-pass filter can be observed simultaneously using an oscilloscope, such as... Figure 4 As shown, the communication receiving device 22 provided in this application can effectively shape the signal output by the single-photon detector 2. Furthermore, the bit error rate was statistically analyzed in 5-minute intervals. After extensive testing, the test results are shown in Table 1. It can be seen that the bit error rate is within the allowable range for general transmission services, verifying the feasibility of the method. This demonstrates that the communication receiving device 22 and communication system provided by this invention are feasible, have a simple structure, low complexity, and are easy to promote and apply.

[0076] Table 1. Simulation Experiment Test Results

[0077]

[0078]

[0079] Please refer to Figure 5 , Figure 5 This is a schematic diagram of a communication system provided by the present invention. To solve the above-mentioned technical problems, the present invention also provides a communication system, including a communication transmitting device 21 and a communication receiving device 22 as described above, wherein the communication transmitting device 21 and the communication receiving device 22 are connected.

[0080] In practical applications, in addition to the communication receiving device 22 mentioned above, the communication system also has a corresponding communication transmitting device 21. This application does not make any special restrictions on the specific type and implementation method of the communication transmitting device 21. There are also multiple options for the connection method between the communication transmitting device 21 and the communication receiving device 22. This application does not make any special restrictions here, and the choice can be made according to the actual application environment.

[0081] In a preferred embodiment, a variable attenuator is also included, with its input terminal connected to the output terminal of the communication transmitting device 21 and its output terminal connected to the communication receiving device 22.

[0082] The variable attenuator is used to adjust the power of the optical signal output by the communication transmitter 21 so that the communication receiver 22 can receive the optical signal.

[0083] Considering that the power of the optical signal that the communication receiving device 22 can receive is usually within a certain range, a variable attenuator can be added to the front end of the communication receiving device 22 in practical applications or simulation experiments. The variable attenuator can adjust the optical power reaching the communication receiving device 22 to ensure that the communication receiving device 22 can receive the optical signal output by the communication transmitting device 21. This application does not specifically limit the specific type and implementation of the variable attenuator.

[0084] Specifically, the added variable attenuator can adjust the optical power reaching the communication receiving device 22, ensuring that the communication receiving device 22 can receive the optical signal output by the communication transmitting device 21, thus guaranteeing the accurate transmission of the entire communication data and improving the accuracy and reliability of the communication system.

[0085] For a description of the communication system provided by the present invention, please refer to the embodiment of the communication receiving device 22 described above; further details will not be repeated here.

[0086] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only 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 thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A communication receiving device, characterized in that, It includes a signal receiving module, a single-photon detector, a filter, and a processing module; the output terminal of the signal receiving module is connected to the input terminal of the single-photon detector, the output terminal of the single-photon detector is connected to the input terminal of the filter, and the output terminal of the filter is connected to the input terminal of the processing module. The single-photon detector is used to convert the optical signal received by the signal receiving module into a pulse sequence; The filter is used to shape the pulse sequence output by the single-photon detector into a level signal output; The processing module is used to obtain communication data based on the level signal; the cutoff frequency of the filter is proportional to the communication rate of the communication receiving device.

2. The communication receiving device as described in claim 1, characterized in that, The processing module is also used for, Obtain the communication rate of the communication receiving device; The target cutoff frequency of the filter is obtained by multiplying the communication rate by a preset factor. The cutoff frequency of the filter is adjusted to the target cutoff frequency.

3. The communication receiving device as described in claim 2, characterized in that, When the filter is an RC filter, adjusting the cutoff frequency of the filter to the target cutoff frequency includes: Adjust the values ​​of the resistors and / or capacitors in the filter to adjust the cutoff frequency of the filter to the target cutoff frequency.

4. The communication receiving device as described in claim 1, characterized in that, The filter is a low-pass filter, and the cutoff frequency of the low-pass filter is less than the frequency of the pulse sequence.

5. The communication receiving device as described in claim 1, characterized in that, The single-photon detector is an avalanche photodiode.

6. The communication receiving device according to any one of claims 1 to 5, characterized in that, The processing module is a voltage comparator, and the input terminal of the voltage comparator is connected to the output terminal of the filter. The voltage comparator outputs logic 1 when the level signal is greater than a preset threshold and outputs logic 0 when the level signal is less than the preset threshold.

7. A communication system, characterized in that, It includes a communication transmitting device and a communication receiving device as described in any one of claims 1 to 6, wherein the communication transmitting device and the communication receiving device are connected.

8. The communication system as described in claim 7, characterized in that, It also includes a variable attenuator, the input of which is connected to the output of the communication transmitting device, and the output of which is connected to the communication receiving device; The variable attenuator is used to adjust the power of the received optical signal output by the communication transmitting device so that the communication receiving device can receive the optical signal.

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