Relay unit, system, method and equipment for optical communication and storage medium

Abstract

The invention relates to a relay unit, system, method and device for optical communication and a storage medium, the relay unit comprises a photoelectric detector and a first signal processing module, and the photoelectric detector is configured to convert a received downlink optical beam into a downlink digital signal and send the downlink digital signal to the first signal processing module; wherein if the downlink optical beam is the optical beam corresponding to the non-target user unit, the downlink optical beam is the optical beam subjected to space zero-forcing processing; the first signal processing module is configured to receive a downlink digital signal and perform first setting processing on the downlink digital signal; wherein if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting processing comprises adding a preset noise signal. According to the invention, the signal eavesdropped by the non-target user unit is mainly the preset noise signal, so that the non-target user unit is prevented from eavesdropping the signal corresponding to the target user unit, and the safety of optical communication is improved.

Description

Technical Field

[0001] The present application relates to the technical field of parking space recognition, and in particular to a relay unit, system, method, device and storage medium for optical communication. Background Art

[0002] In recent years, the continuous improvement of the degree of social informatization has posed a huge challenge to the establishment of a communication network system with fast transmission speed, large information capacity and wide coverage space. In addition, the limited global spectrum resources are in serious shortage due to the sharp increase in user units and services, which is obviously unbearable for radio frequency (RF) communications.

[0003] In this context, wireless optical communication, as a new communication technology using light waves as carrier waves, has emerged, providing abundant spectrum resources for the increasingly scarce radio frequency resources and is the best solution for achieving high-speed and high-capacity communications. However, in the scenario of outdoor long-distance wireless optical communication, due to the instability of the optical communication link and the reduction of confidentiality and security, there are still security issues in information transmission. Summary of the invention

[0004] One of the objects of the present application is to provide a relay unit for optical communication, which can improve the security of information transmission in optical communication; the second object of the present application is to provide an optical communication system; the third object of the present application is to provide an optical communication method; the fourth object of the present application is to provide an optical communication device; and the fifth object of the present application is to provide a storage medium.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present application provides a relay unit for optical communication, wherein the relay unit comprises a photodetector and a first signal processing module.

[0006] The photodetector is configured to convert the received downlink optical beam into a downlink digital signal and then send it to the first signal processing module; if the downlink optical beam is an optical beam corresponding to a non-target user unit, the downlink optical beam is an optical beam that has been subjected to spatial zero forcing processing;

[0007] The first signal processing module is configured to receive the downlink digital signal and perform a first setting process on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal.

[0008] Furthermore, the first signal processing module includes a filter,

[0009] The first signal processing module is configured to add the preset noise signal to the downlink digital signal after filtering by the filter if it is determined that the received downlink digital signal is a signal corresponding to a non-target user unit.

[0010] Further, the relay unit includes a first optical transmitter module, and the first setting process includes a digital-to-analog conversion process;

[0011] The first signal processing module is configured to send a downlink analog signal to the first optical transmitter module; wherein the downlink analog signal is a signal obtained by processing the downlink digital signal by the first setting;

[0012] The first optical transmission module is configured to generate and transmit an optical beam having a non-Lambertian property based on the received downlink analog signal.

[0013] Furthermore, the first optical transmission module includes a light source array composed of a plurality of first light emitting devices, and the first light emitting devices include a switch decision device and a light transmitter.

[0014] Further, the relay unit includes a second signal processing module and a second optical transmission module;

[0015] The photoelectric detector is configured to convert the received uplink optical beam into an uplink digital signal and then send it to the second signal processing module;

[0016] The second signal processing module is configured to perform a second setting process on the received uplink digital signal, and send the processed uplink analog signal to the second optical transmitter module; wherein the second setting process includes a digital-to-analog conversion process;

[0017] The second optical transmission module is configured to generate and transmit an optical beam having the same Lambertian property based on the received uplink analog signal.

[0018] Furthermore, the second light emitting module includes a light source array composed of a plurality of second light emitting devices, and the second light emitting device includes a light emitter.

[0019] In order to achieve the above-mentioned purpose, in a second aspect, the present application further provides an optical communication system, which includes a user unit, a transmitting unit and the relay unit as described above.

[0020] To achieve the above objectives, in a third aspect, the present application further provides an optical communication method, the optical communication method comprising:

[0021] Receiving a downlink optical beam; wherein, if the downlink optical beam is an optical beam corresponding to a non-target user unit, the downlink optical beam is an optical beam that has undergone spatial zero forcing processing;

[0022] Performing analog-to-digital conversion on the downlink optical beam to obtain a downlink digital signal;

[0023] A first setting process is performed on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal.

[0024] Further, the performing a first setting process on the downlink digital signal includes:

[0025] If it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the preset noise signal is added to the downlink digital signal after filtering.

[0026] Further, the first setting process includes a digital-to-analog conversion process, and the optical communication method includes:

[0027] Based on the downlink analog signal obtained by performing the first setting process on the downlink digital signal, an optical beam having a non-Lambertian property is generated and transmitted.

[0028] Furthermore, the optical communication method comprises:

[0029] Receive uplink optical beam;

[0030] Performing analog-to-digital conversion on the uplink optical beam to obtain an uplink digital signal;

[0031] Performing a second setting process on the uplink digital signal; wherein the second setting process includes a digital-to-analog conversion process;

[0032] Based on the uplink analog signal obtained by performing the second setting process on the uplink digital signal, an optical beam having the same Lambertian characteristic is generated and transmitted.

[0033] To achieve the above objectives, in a fourth aspect, the present application further provides an optical communication device, comprising: a processor and a memory, wherein the processor is used to execute a control program stored in the memory to implement the optical communication method as described above.

[0034] To achieve the above objectives, in a fifth aspect, the present application also provides a storage medium, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the optical communication method as described above.

[0035] Beneficial effects of this application:

[0036] In the present application, spatial zero forcing processing can be performed on the downlink optical beam corresponding to the non-target user unit, and after the relay unit converts the above-mentioned downlink optical beam into a downlink digital signal, a preset noise signal can be added to the digital signal, so that the signal eavesdropped by the non-target user unit is mainly the preset noise signal, so as to avoid the non-target user unit eavesdropping on the signal corresponding to the target user unit, thereby improving the security of optical communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram showing a relay unit for optical communication provided in an embodiment of the present application is shown;

[0038] Figure 2 A schematic diagram of an optical communication system provided by an embodiment of the present application is shown;

[0039] Figure 3 A schematic diagram showing a flow chart of an optical communication method provided in an embodiment of the present application is shown;

[0040] Figure 4 A schematic diagram of an optical communication device provided by an embodiment of the present application is shown;

[0041] in:

[0042] 1. Relay unit; 11. Photoelectric detector; 12. First signal processing module; 13. First optical transmission module; 14. Second signal processing module; 15. Second optical transmission module; 21. Target user unit; 22. Non-target user unit; 3. Transmitting unit;

[0043] 100, optical communication equipment; 101, processor; 102, memory; 1021, operating system; 1022, application program; 103, user unit interface; 104, network interface; 105, bus system;

[0044] 2. Space parking space; 200, first reference car; 300, second reference car; 400, third reference car; 500, fourth reference car. DETAILED DESCRIPTION

[0045] The following will describe the implementation methods of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the scope of protection of the present application.

[0046] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0047] The following will describe the implementation methods of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the scope of protection of the present application.

[0048] To facilitate understanding of the embodiments of the present application, further explanation will be given below with reference to specific embodiments in conjunction with the accompanying drawings. The embodiments do not constitute a limitation on the embodiments of the present application.

[0049] This embodiment provides a relay unit for optical communication. Figure 1 and 2 As shown, the optical communication system generally includes a user unit, a relay unit 1 and a transmitting unit 3. The user unit transmits an uplink signal to the transmitting unit 3 through the relay unit 1, and the transmitting unit 3 sends a downlink signal to the user unit through the relay unit 1 in response to the received uplink signal. The above signal can be a digital signal or an optical signal (such as an optical beam). The user unit can include a target user unit 21 and can also include a non-target user unit 22 (i.e., an eavesdropping user unit).

[0050] The relay unit 1 may include a photodetector 11 and a first signal processing module 12. The photodetector 11 may refer to a device or a combination of devices that can convert an optical signal into an electrical signal. The first signal processing module 12 refers to a device or a combination of devices that can process a signal.

[0051] The photodetector 11 may be configured to convert the received downlink optical beam into a downlink digital signal and then send it to the first signal processing module 12; if the downlink optical beam is an optical beam corresponding to the non-target user unit 22, the downlink optical beam is an optical beam that has been processed by spatial zero forcing. That is, the photodetector 11 may receive the downlink optical beam sent by the transmitting unit 3, and after converting the downlink optical beam into a downlink digital signal, send the downlink digital signal to the first signal processing module 12. The downlink digital signal may include multiple digital signals, that is, in the downlink optical beam, each optical signal may be converted into a downlink digital signal, thereby obtaining a downlink digital signal corresponding to the entire downlink optical beam.

[0052] Among them, when the downlink optical beam is an optical beam corresponding to the non-target user unit 22, the transmitting unit 3 can perform spatial zero forcing on the optical beam when forming the downlink optical beam to obtain a downlink optical beam after spatial zero forcing. When the downlink optical beam is an optical beam corresponding to the target user unit 21, the transmitting unit 3 does not need to perform spatial zero forcing on the optical beam when forming the downlink optical beam. In this way, the security of information transmission can be improved.

[0053] The first signal processing module 12 is configured to receive a downlink digital signal and perform a first setting process on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit 22, the first setting process includes adding a preset noise signal.

[0054] That is, after receiving the downlink digital signal sent by the photodetector 11, the first signal processing module 12 can perform the first setting processing on the downlink digital signal, and send the processed downlink digital signal to the first optical transmission module 13. The processing method included in the first setting processing can be set according to actual needs, for example, it can include filtering, amplification, digital-to-analog conversion, etc., which is not limited.

[0055] When the downlink digital signal is a signal corresponding to the target user unit 21, the first setting process may not include adding a preset noise signal. That is, when the downlink digital signal is converted from the downlink optical beam corresponding to the target user unit 21, the first signal processing module 12 does not need to add a preset noise signal to the downlink digital signal.

[0056] When the downlink digital signal is a signal corresponding to the non-target user unit 22, the first setting process includes adding a preset noise signal. That is, when the downlink digital signal is converted from a downlink optical beam corresponding to the non-target unit, the first signal processing module 12 needs to add a preset noise signal to the downlink digital signal.

[0057] It should be noted that the preset noise signal can be set according to actual needs, and there is no limitation on its specific noise. The preset noise signal can be a natural noise signal or an artificially synthesized noise signal, without limitation. The preset noise signal can be set before the optical communication equipment leaves the factory, or it can be set after the optical communication equipment leaves the factory, without limitation. After the preset noise signal is set, it can be modified according to the actual situation to better meet different needs.

[0058] The first setting process may include filtering, amplification, and digital-to-analog conversion, etc., that is, the first signal processing module 12 may include devices such as filters, amplifiers, and digital-to-analog converters, which are not limited. When the first signal processing module 12 includes a filter, the first signal processing module 12 is configured to add a preset noise signal to the downlink digital signal after filtering by the filter if it is determined that the received downlink digital signal is a signal corresponding to the non-target user unit 22.

[0059] That is, when the first setting process includes filtering, after the first signal processing module 12 receives the downlink digital signal, it can add the preset noise signal after filtering the downlink digital signal. That is, the operation of adding the preset noise signal is located after the filtering process to avoid filtering out the preset noise signal by the filtering process, so as to better ensure that the signal output by the first signal processing module 12 is added with the complete preset noise signal.

[0060] The relay unit 1 may include a first optical transmitter module 13. The first signal processing module 12 may also be configured to send a downlink analog signal to the first optical transmitter module 13; wherein the downlink analog signal is a signal obtained by processing the downlink digital signal through a first setting. The first optical transmitter module 13 may be configured to generate and send an optical beam having a non-Lambertian characteristic based on the received downlink analog signal.

[0061] That is, after the first signal processing module 12 performs the first setting processing on the received downlink digital signal, a downlink analog signal can be obtained, and then the downlink analog signal can be sent to the first optical transmitter module 13. After receiving the downlink analog signal, the first optical transmitter module 13 can generate and send an optical beam with non-Lambertian characteristics based on the downlink analog signal.

[0062] The first optical transmitter module 13 may include a light source array composed of a plurality of (e.g., Narray) first optical transmitter devices, and each first optical transmitter device may include a switch to determine the optical transmitter device, thereby making the optical beams emitted by each first optical transmitter device different, so as to achieve a differentiated coverage effect. In other words, the optical beam emitted by the first optical transmitter module 13 is non-Lambertian and can be sent to a receiving end (e.g., a user unit) in a directionally manner.

[0063] It should be noted that, in addition to the above-mentioned structure, the first optical transmission module 13 may also be configured as other structures, which is not limited thereto.

[0064] In the optical communication, the downlink optical beam corresponding to the non-target user unit 22 can be subjected to spatial zero forcing, and after the relay unit 1 converts the downlink optical beam into a downlink digital signal, a preset noise signal can be added to the digital signal, so that the signal eavesdropped by the non-target user unit 22 is mainly the preset noise signal, so as to avoid the non-target user unit 22 eavesdropping on the signal corresponding to the target user unit 21, thereby improving the security of the optical communication. In addition, since the optical beam emitted by the first optical transmitter module 13 has a non-Lambertian property, the power of the received optical beam of the user unit can be better improved, further improving the user experience.

[0065] This embodiment provides a relay unit 1 for optical communication. Figure 1 and 2 As shown, the relay unit 1 may include a second signal processing module 14 and a second optical transmission module 15 .

[0066] The photodetector 11 may be configured to convert the received uplink optical beam into an uplink digital signal and then send it to the second signal processing module 14. That is, the photodetector 11 may receive an uplink optical beam sent from a user unit (e.g., a target user unit 21 or a non-target user unit 22). After receiving the uplink optical beam, the photodetector 11 may perform analog-to-digital conversion on the uplink optical beam to obtain an uplink digital signal. The uplink digital signal may include multiple digital signals, that is, in the uplink optical beam, each optical signal may be converted into an uplink digital signal to obtain an uplink digital signal corresponding to the entire uplink optical beam.

[0067] It should be noted that the photoelectric detector 11 may process the uplink optical beam in the same manner as the photoelectric detector 11 processes the downlink optical beam.

[0068] The second signal processing module 14 may be configured to perform a second setting process on the received uplink digital signal, and send the processed uplink analog signal to the second optical transmitter module 15. The second setting process may include a digital-to-analog conversion process. The second setting process may also include a filtering process, an amplification process, a comparison and screening process, or a modulation process, etc., which is not limited thereto.

[0069] That is, after receiving the uplink digital signal sent by the photodetector 11 , the second signal processing module 14 can perform the second setting processing on the uplink digital signal to finally obtain the uplink analog signal, and then send the uplink analog signal to the second optical transmitter module 15 .

[0070] The second signal processing module 14 may include a filter, an amplifier, a memory, a comparator, a modulation module and a digital-to-analog converter. The above-mentioned various devices may be composed of a single device or a combination of multiple devices.

[0071] After the photodetector 11 obtains the uplink digital signal based on the uplink optical beam, the uplink digital signal can be transmitted to the filter for filtering. The filter transmits the filtered uplink digital signal to the amplifier for amplification. The amplifier transmits the amplified uplink digital signal to the memory for storage. Then the memory transmits the uplink digital signal to the comparator. The comparator can compare the strength of each digital signal in the received uplink digital signal, select the uplink digital signal with the largest strength, and then transmit it to the modulation module for coding and modulation. The modulated signal is then transmitted to the digital-to-analog converter for conversion from the digital signal to the analog signal to obtain the uplink analog signal.

[0072] The second optical transmitter module 15 can be configured to generate and send optical beams with the same Lambertian property based on the received uplink analog signal. That is, after receiving the uplink analog signal, the second optical transmitter module 15 can generate and send multiple optical beams with the same Lambertian property based on the uplink analog signal.

[0073] The second optical transmitter module 15 may include a light source array consisting of a plurality of (e.g., Narray) second optical transmitter devices. Each second optical transmitter device may include a transmitter. Thus, the optical beams emitted by the second optical transmitter devices are not different, that is, the optical beams emitted by the second optical transmitter module 15 are Lambertian, that is, the second optical transmitter module 15 outputs the same multi-channel modulated data stream.

[0074] In the optical communication, the relay unit 1 outputs the uplink signal as an optical beam with Lambertian characteristics through the second optical transmitter module 15, and outputs the downlink signal as an optical beam with non-Lambertian characteristics through the first optical transmitter module 13. The relay unit 1 can well improve the optical power and further enhance the user experience by selecting and switching the first optical transmitter module 13 and the second optical transmitter module 15.

[0075] It should be noted that in the present application, the uplink signal refers to the signal transmitted from the receiving end (i.e., the user unit) to the transmitting end (i.e., the transmitting unit 3) via the relay unit 1, which includes types such as analog signals (e.g., uplink optical beam, uplink analog signal) and digital signals (e.g., uplink digital signal); the downlink signal refers to the signal transmitted from the transmitting end to the receiving end via the relay unit 1, which includes types such as analog signals (e.g., downlink optical beam, downlink analog signal) and digital signals (e.g., downlink digital signal).

[0076] This embodiment provides an optical communication system, referring to Figure 1 and 2 As shown, the optical communication system may include a user unit, a transmitting unit 3 and the above-mentioned relay unit 1.

[0077] Among them, in some long-distance optical communication scenarios, there are both legal target users and illegal non-target users in the user unit.

[0078] The target user loads the data stream carrying its own identification data (for example, recorded as a=[a1…ai]) to the third optical transmitter module (the specific structure of the third optical transmitter module may not be limited. For example, in this embodiment, the third optical transmitter module may be the same as the second optical transmitter module 15, and the second optical transmitter module 15 includes a light source array composed of Narray second optical transmitter devices), and the third optical transmitter module may send the first uplink optical beam (for example, recorded as A=[A1…Ai]) to the relay unit 1. i is a positive integer, which may be determined according to actual conditions, and its specific value may not be limited.

[0079] The non-target user loads the data stream carrying its own identification data (for example, recorded as b=[b1…bi]) to the fourth optical transmitter module (the specific structure of the third optical transmitter module may not be limited, for example, the third optical transmitter module may be the same as the second optical transmitter module 15), and the fourth optical transmitter module sends a second uplink optical beam (for example, recorded as B=[B1…Bj]) to the relay unit 1.

[0080] After receiving the first uplink optical beam and the second uplink optical beam carrying the modulated data stream through the photodetector 11, the relay unit 1 can convert the received uplink optical beam into an uplink digital signal. The photodetector 11 obtains the first uplink digital signal based on the first uplink optical beam, and the photodetector 11 obtains the second uplink digital signal based on the second uplink optical beam.

[0081] Then, after filtering and amplification, the uplink digital signal can be transmitted to the memory for storage based on the identification data (i.e., a or b) carried by the uplink digital signal. Then, the memory transmits the stored uplink digital signal to the comparator, and the comparator compares the strengths of the first uplink digital signal and the second uplink digital signal, respectively, and selects the first maximum strength signal (e.g., recorded as Amax) with the largest strength after the first uplink digital signal, and the second maximum strength signal (e.g., recorded as Bmax) with the largest strength in the second uplink digital signal.

[0082] The comparator transmits the screened maximum intensity signal to the modulation module, and the modulation module can perform coding modulation on the screened first maximum intensity signal and the second maximum intensity signal, and convert them into uplink analog signals through the digital-to-analog converter after modulation, and load the corresponding identification data and send them to the second optical transmitter module 15. Among them, the uplink analog signal includes the first uplink analog signal corresponding to the first maximum intensity signal and the second uplink analog signal corresponding to the second maximum intensity signal. Among them, the modulation module may include a modulator, a power divider, and a switch decision device, etc., which are not limited to this.

[0083] The second optical transmitter module 15 generates and transmits a modulated data stream optical beam carrying identification data based on the received first uplink analog signal and the second uplink analog signal. The optical beam may include a first modulated optical beam corresponding to the first uplink analog signal (e.g., denoted as A'max) and a second modulated optical beam corresponding to the second uplink analog signal (e.g., denoted as B'max).

[0084] The transmitting unit 3 can receive the modulated data stream optical beam (such as A'max and B'max) carrying the identification data through its own photodetector. It is assumed that the transmitting unit 3 already knows the channel state information (CSI, i.e., Channel State Information, which refers to the channel properties of the communication link and describes the attenuation factor of the signal on each transmission path, i.e., the value of each element in the channel gain matrix H, such as signal scattering, environmental attenuation, and distance attenuation) of the channel corresponding to the non-target user unit 22.

[0085] Among them, for the information corresponding to the non-target user unit 22, the transmitting unit 3 constructs the channel gain (or channel vector) of the non-target user unit 22 based on the channel state information:

[0086] in[.] T represents the matrix transpose operation. Refers to the channel gain from the ith optical transmitter to the non-target user. Then, the (Narray-1) null space column vectors corresponding to the vector can be obtained (the vector size is 1×Narray). The (Narray-1) column vectors are combined into a null space matrix Ψeve of size Narray×(Narray-1).

[0087] Construct a spatial zeroing weight matrix Wnulleve=αΨeveΨ based on the null space matrix Ψeve T eve heve. Among them, α is the scaling factor of the spatial zero weight matrix, Ψ T eveis the transposed matrix of Ψeve. In addition, the value of α is adjusted so that the absolute amplitude value of each element of the matrix Wnulleve is not greater than 1.

[0088] The transmitting unit 3 weights the second modulated optical beam based on the above heve and Wnulleve, and then transmits the second modulated optical beam carrying the weighted signal to the relay unit 1. In addition, the transmitting unit 3 can determine Wnullbob (the weight matrix of the target user) based on hbob (the channel gain of the target user unit 21), and then weights the first modulated optical beam based on the above hbob and Wnullbob, and then transmits the first modulated optical beam carrying the weighted signal to the relay unit 1.

[0089] The photodetector 11 of the relay unit 1 performs analog-to-digital conversion on the first modulated optical beam carrying the weighted signal to obtain a first downlink digital signal, and the photodetector 11 of the relay unit 1 performs analog-to-digital conversion on the second modulated optical beam carrying the weighted signal to obtain a second downlink digital signal.

[0090] The filter of the relay unit 1 filters out other interference signals in the first downlink digital signal and the second downlink digital signal, and adds a preset noise signal zeve to the second downlink digital signal based on the identification data. Then, the amplifier amplifies the signal to obtain the amplified first downlink digital signal and the second downlink digital signal, respectively, wherein the preset noise signal is added to the second downlink digital signal. After the digital-to-analog converter receives the first downlink digital signal and the second downlink digital signal sent by the amplifier, it can perform digital-to-analog conversion processing on them to obtain the first downlink analog signal corresponding to the first downlink digital signal and the second downlink analog signal corresponding to the first downlink digital signal, and then transmit them to the first optical transmitter module 13.

[0091] After the first optical transmitter module 13 receives the first downlink analog signal, it can generate a non-Lambertian optical beam based on the first downlink analog signal. The target user unit 21 receives the corresponding optical beam, and then demodulates it through its own demodulator to obtain information corresponding to the target user unit 21. Correspondingly, after the first optical transmitter module 13 receives the second downlink analog signal, it can generate a non-Lambertian optical beam based on the second downlink analog signal. The non-target user unit 22 receives the corresponding optical beam, and then demodulates it through its own demodulator to obtain information corresponding to the non-target user unit 22.

[0092] The signal captured by the non-target user unit 22 can be expressed as:

[0093] yeve=amod_ind×PDC×heve×Wnulleve×d+zeve

[0094] =amod_ind×PDC×0×d+zeve

[0095] =zeve;

[0096] Among them, amod_ind is the modulation index of the light source, PDC is the DC bias, d is the raw data, and zeve is the preset noise signal.

[0097] The received signal-to-noise ratio of the non-target user unit 22 can be expressed as: SNReve = 0 / σ 2 =0.

[0098] The signal captured by the target user unit 21 can be expressed as:

[0099] ybob=amod_ind×PDC×hbob×Wnullbob×d.

[0100] Among them, amod_ind is the modulation index of the light source, PDC is the DC bias, Wnullbob is the weight matrix determined based on hbob, and d is the original data.

[0101] The received signal-to-noise ratio of the target user unit 21 can be expressed as:

[0102] SNRbob = [a 2 mod_ind (P DC ) 2 (h bob ) T W nullbob (W nulbobl ) T h bob ] / σ 2

[0103] Among them, σ 2 represents the noise variance.

[0104] It can be seen from this that the safe rate of the optical communication system is:

[0105] C s =SNR bob / SNR bob =∞.

[0106] This application is different from the single use of relay amplification or relay decoding technology. The proposed relay technology adopts the above two forwarding protocols at the same time, and introduces a feedback mechanism to screen the optical beam with the highest intensity at the relay end and feed back the data stream and identification data to the transmitting unit 3. The transmitting unit 3 obtains the information of the target user according to the identification data and the data stream, sends the confidential data to the target user unit 21, and constructs a zero-forcing matrix through the channel state information, so that the projection of the projection matrix of the related vector of the channel matrix of the non-target user unit 22 in the null space is set to zero. Taking into account the physical characteristics and transmission characteristics of the optical beam of the commercial light source, it has the advantages of reducing self-interference and reducing the optical power of the eavesdropping channel, and can achieve higher security transmission performance with lower system complexity, and can further improve the reliability and effectiveness of optical communication under long-distance optical communication conditions.

[0107] In addition, the long-distance wireless optical communication method of the present application can achieve differentiated optical signal coverage for the receiving end and has a variety of scene adaptability. The various scene adaptability includes but is not limited to: (1) long-distance confidential information interaction scenarios between vehicles with directional non-Lambertian commercial solid-state light sources; (2) long-distance confidential information interaction scenarios between vehicles and traffic facilities with directional non-Lambertian commercial solid-state light sources; (3) long-distance confidential information interaction scenarios between traffic facilities with directional non-Lambertian commercial solid-state light sources; (4) long-distance confidential positioning application scenarios of directional non-Lambertian commercial solid-state light sources; (5) long-distance confidential sensing application scenarios of directional non-Lambertian commercial solid-state light sources, etc. Of course, other scenarios may also be included, which are not limited to this.

[0108] This embodiment provides an optical communication method, which is applied to an optical communication device, for example, to a relay unit in the optical communication device. Figure 3 As shown, the method may include:

[0109] S110, receiving a downlink optical beam; wherein, if the downlink optical beam is an optical beam corresponding to a non-target user unit, the downlink optical beam is an optical beam that has undergone spatial zero forcing processing;

[0110] S120, performing analog-to-digital conversion on the downlink optical beam to obtain a downlink digital signal;

[0111] S130, performing a first setting process on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal.

[0112] It should be noted that the above steps are briefly introduced below. The specific processing methods of the above steps can refer to the relevant introduction of the method executed by the relay unit in other embodiments, which will not be described in detail.

[0113] In step S110, a downlink optical beam may be sent by a transmitting unit in optical communication to a relay unit, so that the relay unit receives the downlink optical beam.

[0114] When the downlink optical beam is an optical beam corresponding to a non-target user unit, the transmitting unit can perform spatial zero forcing on the optical beam when forming the downlink optical beam to obtain a downlink optical beam after spatial zero forcing. When the downlink optical beam is an optical beam corresponding to a target user unit, the transmitting unit does not need to perform spatial zero forcing on the optical beam when forming the downlink optical beam. In this way, the security of information transmission can be improved.

[0115] In step S120, after receiving the downlink optical beam, the relay unit may perform analog-to-digital conversion on the downlink optical beam to obtain a corresponding downlink digital signal, so as to facilitate subsequent processing of the signal.

[0116] In step S130, the processing method included in the first setting process can be set according to actual needs, for example, it can include filtering, amplification, digital-to-analog conversion, etc., which is not limited.

[0117] When the downlink digital signal is a signal corresponding to the target user unit, the first setting process may not include adding a preset noise signal. In other words, when the downlink digital signal is converted from a downlink optical beam corresponding to the target user unit, the first signal processing module does not need to add a preset noise signal to the downlink digital signal.

[0118] When the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal. That is, when the downlink digital signal is converted from a downlink optical beam corresponding to a non-target unit, the first signal processing module needs to add a preset noise signal to the downlink digital signal.

[0119] In the optical communication method, a spatial zero-forcing process can be performed on a downlink optical beam corresponding to a non-target user unit, and after the downlink optical beam is converted into a downlink digital signal, a preset noise signal can be added to the digital signal, so that the signal eavesdropped by the non-target user unit is mainly the preset noise signal, so as to avoid the non-target user unit eavesdropping on the signal corresponding to the target user unit, thereby improving the security of optical communication.

[0120] The present embodiment provides an optical communication device. The optical communication device can be a device in various fields. For example, large-screen devices in the field of smart home, artificial intelligence (AI) speakers, high fidelity (HiFi) speakers, temperature sensors, humidity sensors, etc. As well as mobile phones, tablet computers, wearable devices, augmented reality (AR) / virtual reality (VR) devices, laptops, ultra-mobile personal computers (UMPC), netbooks, personal digital assistants (PDA), etc. in the field of smart terminals. As well as robotic arms, cameras, joysticks, monitors, sensors, logistics vehicles, smart shelves, etc. in the field of intelligent manufacturing. It can also be a car, tram or other vehicle. The present application embodiment does not impose any restrictions on the specific type of optical communication equipment, as long as it can achieve optical communication.

[0121] refer to Figure 4 As shown, the optical communication device 100 includes: at least one processor 101, a memory 102, at least one network interface 104 and other user unit interfaces 103. The various components in the optical communication device 100 are coupled together through a bus system 105. It can be understood that the bus system 105 is used to realize the connection communication between these components. In addition to the data bus, the bus system 105 also includes a power bus, a control bus and a status signal bus. However, for the purpose of clear description, various buses are marked as bus system 105.

[0122] The user unit interface 103 may include a display, a keyboard, or a pointing device (eg, a mouse, a trackball, a touch pad, or a touch screen).

[0123] It can be understood that the memory 102 in the embodiment of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 102 described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0124] In some implementations, the memory 102 stores the following elements, executable units or data structures, or a subset thereof, or an extended set thereof: an operating system 1021 and application programs 1022 .

[0125] Among them, the operating system 1021 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application 1022 includes various application programs, such as a media player (Media Player), a browser (Browser), etc., which are used to implement various application services. The program that implements the method of the embodiment of the present application can be included in the application 1022.

[0126] In the embodiment of the present application, by calling the program or instruction stored in the memory 102, specifically, the program or instruction stored in the application 1022, the processor 101 is used to execute the method provided by each method embodiment.

[0127] The method disclosed in the above embodiment of the present application can be applied to the processor 101, or implemented by the processor 101. The processor 101 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit in the processor 101 or the instruction in the form of software. The above processor 101 can be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to execute, or the hardware and software units in the decoding processor can be executed. The software unit can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 102, and the processor 101 reads the information in the memory 102 and completes the method executed by the above-mentioned relay unit in combination with its hardware.

[0128] It is understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit may be implemented in one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPDevice, DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), general purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in the present application, or a combination thereof.

[0129] For software implementation, the technology described herein can be implemented by a unit that performs the functions described herein. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or outside the processor.

[0130] The embodiment of the present application also provides a storage medium (computer-readable storage medium). The storage medium here stores one or more programs. The storage medium may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a read-only memory, a flash memory, a hard disk or a solid-state drive; the memory may also include a combination of the above-mentioned types of memory.

[0131] When one or more programs in the storage medium can be executed by one or more processors, the method executed in the relay unit of the optical communication device is implemented.

[0132] The processor is used to execute the control program of the optical communication device stored in the memory to implement the above method executed in the relay unit of the optical communication device.

[0133] The professionals should also be further aware that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0134] It should be noted that the phrases "one implementation", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0135] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0136] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present application is within the protection scope of the present application.

Claims

1. A relay unit for optical communication, characterized in that: The relay unit includes a photoelectric detector and a first signal processing module, The photodetector is configured to convert the received downlink optical beam into a downlink digital signal and then send it to the first signal processing module; if the downlink optical beam is an optical beam corresponding to a non-target user unit, the downlink optical beam is an optical beam that has been subjected to spatial zero forcing processing; The first signal processing module is configured to receive the downlink digital signal and perform a first setting process on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal.

2. The optical communication relay unit according to claim 1, characterized in that: The first signal processing module includes a filter, The first signal processing module is configured to add the preset noise signal to the downlink digital signal after filtering by the filter if it is determined that the received downlink digital signal is a signal corresponding to a non-target user unit.

3. The optical communication relay unit according to claim 1, characterized in that: The relay unit includes a first optical transmitter module, and the first setting process includes a digital-to-analog conversion process; The first signal processing module is configured to send a downlink analog signal to the first optical transmitter module; wherein the downlink analog signal is a signal obtained by processing the downlink digital signal through the first setting; The first optical transmission module is configured to generate and transmit an optical beam having a non-Lambertian property based on the received downlink analog signal.

4. The optical communication relay unit according to claim 3, characterized in that: The first optical transmission module includes a light source array composed of a plurality of first light emitting devices, and the first light emitting devices include a switch decision device and a light transmitter.

5. The optical communication relay unit according to any one of claims 1 to 4, characterized in that: The relay unit includes a second signal processing module and a second optical transmission module; The photoelectric detector is configured to convert the received uplink optical beam into an uplink digital signal and then send it to the second signal processing module; The second signal processing module is configured to perform a second setting process on the received uplink digital signal, and send the processed uplink analog signal to the second optical transmitter module; wherein the second setting process includes a digital-to-analog conversion process; The second optical transmission module is configured to generate and transmit an optical beam having the same Lambertian property based on the received uplink analog signal.

6. The optical communication relay unit according to claim 5, characterized in that: The second light emitting module includes a light source array composed of a plurality of second light emitting devices, and the second light emitting device includes a light emitter.

7. An optical communication system, characterized in that: The optical communication system comprises a user unit, a transmitting unit and a relay unit as claimed in any one of claims 1 to 6.

8. An optical communication method, characterized in that: The optical communication method comprises: Receiving a downlink optical beam; wherein, if the downlink optical beam is an optical beam corresponding to a non-target user unit, the downlink optical beam is an optical beam that has undergone spatial zero forcing processing; Performing analog-to-digital conversion on the downlink optical beam to obtain a downlink digital signal; A first setting process is performed on the downlink digital signal; wherein, if it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the first setting process includes adding a preset noise signal.

9. The optical communication method according to claim 8, characterized in that: The performing a first setting process on the downlink digital signal includes: If it is determined that the downlink digital signal is a signal corresponding to a non-target user unit, the preset noise signal is added to the downlink digital signal after filtering.

10. The optical communication method according to claim 8, characterized in that: The first setting process includes a digital-to-analog conversion process, and the optical communication method includes: Based on the downlink analog signal obtained by performing the first setting process on the downlink digital signal, an optical beam having a non-Lambertian property is generated and transmitted.

11. The optical communication method according to any one of claims 8 to 10, characterized in that: The optical communication method comprises: Receive uplink optical beam; Performing analog-to-digital conversion on the uplink optical beam to obtain an uplink digital signal; Performing a second setting process on the uplink digital signal; wherein the second setting process includes a digital-to-analog conversion process; Based on the uplink analog signal obtained by performing the second setting process on the uplink digital signal, an optical beam having the same Lambertian characteristic is generated and transmitted.

12. An optical communication device, characterized in that: include: A processor and a memory, wherein the processor is used to execute a control program stored in the memory to implement the optical communication method according to any one of claims 8 to 11.

13. A storage medium, characterized in that: The storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the optical communication method according to any one of claims 8 to 11.

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