Laser communication method, device, equipment and storage medium based on omnidirectional microwave

Abstract

The embodiments of the present disclosure provide a laser communication method, device, equipment and storage medium based on omnidirectional microwaves, which are applied to the field of wireless communication technology. The method includes: based on omnidirectional microwaves, using an adaptive hierarchical beam search algorithm to search for microwave signals of a communication target; judging the quality of the searched signal, if it is greater than a preset threshold, switching to an exhaustive beam search algorithm for a refined search, determining the best beam, obtaining the strongest angle of arrival and generating a corresponding beamforming matrix; sending the beamforming matrix to an optical machine so that the optical machine can quickly capture the communication target light spot, complete alignment, and establish a laser communication link with the communication target for laser communication. In this way, beamforming, alignment of the propagation path, and rapid locking of the communication target can be completed within a low-cost and short-delay period, thereby successfully establishing a high-quality communication link, achieving a complete and efficient connection from signal search to link establishment, and overcoming the limitations of a single communication method.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and further to the field of wireless communication technology, and in particular to a laser communication method, device, equipment and storage medium based on omnidirectional microwaves. Background Art

[0002] In wireless communications, especially satellite-to-ground communications, how to quickly lock onto communication targets, establish communication links and conduct high-quality communications is a difficult problem that can be solved using a microwave laser fusion communication system. The laser calibration system has high accuracy and collects a lot of information, but its calibration process is time-consuming and is not suitable for working in severe weather conditions. Although the millimeter wave system cannot be compared with the laser system in terms of accuracy, the calibration system has a strong ability to penetrate fog and smoke, has high spatial resolution, and can cope with all-weather work in severe weather conditions. The two have their own advantages and disadvantages and can be integrated for application.

[0003] However, to integrate millimeter wave communication and laser communication, we must first face the following problems:

[0004] When the carrier frequency of millimeter wave communication is too high, it will lead to extremely high path loss. In order to overcome the huge path loss in the process of millimeter wave data transmission, it is necessary to use highly directional beamforming technology with a large antenna array. The beamforming technology in millimeter wave communication needs to be completed in a large space and short delay. Therefore, it is very challenging to align the directional beam with the main propagation path. In addition, it is necessary to consider whether the corresponding millimeter wave beam search can continue when the single hardware resources are limited and how to obtain the search results at the lowest cost. These problems are not only the problems that currently plague millimeter wave systems, but also the problems that need to be solved urgently in the integrated application of millimeter wave communication and laser communication. Summary of the invention

[0005] In view of this, the present disclosure provides a laser communication method, device, equipment and storage medium based on omnidirectional microwaves.

[0006] According to a first aspect of the present disclosure, there is provided a laser communication method based on omnidirectional microwaves, which is applied to a communication system. The method comprises:

[0007] Based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning using a preset multi-layer beam codebook to search for microwave signals of communication targets;

[0008] The quality of the searched signal is judged. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam, and generate the corresponding beamforming matrix;

[0009] The beamforming matrix is ​​sent to the optical machine so that the optical machine can quickly capture the communication target light spot, complete the alignment, and establish a laser communication link with the communication target for laser communication.

[0010] In some implementations of the first aspect, based on omnidirectional microwaves, using an adaptive hierarchical beam search algorithm and using a preset multi-layer beam codebook to perform spatial scanning to search for microwave signals of a communication target includes:

[0011] Based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning according to the preset starting layer using a preset multi-layer beam codebook. The main path direction of the millimeter wave channel at the receiving end is determined by searching the pilot signal at the transmitting end.

[0012] In some implementable embodiments of the first aspect, the quality of the searched signal is judged, and if it is greater than a preset threshold, an exhaustive beam search algorithm is switched to perform a refined search, an optimal beam is determined, and a strongest arrival angle is obtained based on the optimal beam and a corresponding beamforming matrix is ​​generated, including:

[0013] GLRT is used to test the quality of the searched signal and determine whether the quality of the currently searched signal is greater than the preset threshold. If so, the hierarchical scanning is stopped and the exhaustive beam search algorithm is switched to perform a refined search. The best beam is determined through the exhaustive beam search, and the strongest arrival angle is obtained based on the best beam and the corresponding beamforming matrix is ​​generated.

[0014] In some implementations of the first aspect, using GLRT to check the quality of the searched signal and determining whether the quality of the currently searched signal is greater than a preset threshold includes:

[0015] The searched pilot signal is subjected to matched filtering, and the matched filtering output is provided with a target signal-to-noise ratio threshold value and a likelihood ratio threshold value, and a GLRT test problem is constructed based on the target signal-to-noise ratio threshold value and the likelihood ratio threshold value;

[0016] A test statistic expression is generated according to the GLRT test problem, and the statistic is calculated using the test statistic expression. According to the comparison result between the calculated statistic and the likelihood ratio threshold value, it is judged whether the SNR of the matched filter output of the beam is higher than the preset target SNR value.

[0017] In some implementations of the first aspect, sending a beamforming matrix to an optical machine so that the optical machine quickly captures a communication target light spot, completes alignment, and establishes a laser communication link with the communication target for laser communication, including:

[0018] The beamforming matrix is ​​format converted and parsed, and the parsed information is sent to the optical machine through a compatible interface so that the optical machine can drive related devices to make adjustments based on the parsed information, so as to quickly capture the communication target light spot, complete alignment, and establish a laser communication link with the communication target for laser communication.

[0019] In some implementations of the first aspect, the method further includes:

[0020] The searched microwave signal is subjected to 1-bit quantization A / D operation, and the probability of each beam being the best beam is calculated through n-fold Bernoulli distribution and the threshold value of the quantization function to generate the best beam detection probability matrix; based on the best beam detection probability matrix, the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix;

[0021] A 1-bit quantized A / D operation is performed on the emitted microwave signal so that the communication target can perform a 1-bit quantized A / D operation on the searched microwave signal, and the probability of each beam becoming the best beam is calculated through the heavy Bernoulli distribution and the threshold value of the quantization function to generate the best beam detection probability matrix; based on the best beam detection probability matrix, the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix.

[0022] In some implementable embodiments of the first aspect, based on the optimal beam detection probability matrix, an adaptive hierarchical beam search algorithm and an exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate a corresponding beamforming matrix, including:

[0023] The optimal beam detection probability matrix is ​​sorted, and the area where the beam with the highest detection probability in the sorted table is located is selected as the initial search area of ​​the adaptive hierarchical beam search algorithm;

[0024] If after searching, it is found that the best beam in the area is the same as the best beam in the area in the best beam detection probability matrix and the signal quality is greater than a preset threshold, the strongest arrival angle is directly obtained based on the best beam and a corresponding beamforming matrix is ​​generated;

[0025] If it is found after the search that the best beam in the area is different from the best beam in the area in the best beam detection probability matrix but the signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam and generate the corresponding beamforming matrix;

[0026] If after searching, it is found that the best beam in the area is different from the best beam in the area in the best beam detection probability matrix, and the signal quality of the best beam is less than the preset threshold, then the hierarchical search is continued until the quality of the searched signal is greater than the preset threshold, and the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam, and generate the corresponding beamforming matrix.

[0027] According to a second aspect of the present disclosure, there is provided a laser communication device based on omnidirectional microwaves, which is applied to a communication system. The device comprises:

[0028] The first processing module is used to perform spatial scanning based on omnidirectional microwaves using an adaptive hierarchical beam search algorithm and a preset multi-layer beam codebook to search for microwave signals of a communication target;

[0029] The second processing module is used to judge the quality of the searched signal. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam, and generate a corresponding beamforming matrix;

[0030] The third processing module is used to send the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot, complete the alignment, and establish a laser communication link with the communication target for laser communication.

[0031] According to a third aspect of the present disclosure, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described above.

[0032] According to a fourth aspect of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, where the computer instructions are used to cause a computer to execute the method described above.

[0033] In the present disclosure, an adaptive hierarchical beam search algorithm is used to search for microwave signals of communication targets based on omnidirectional microwaves for spatial scanning, and target signals are efficiently and targetedly searched in a larger search space, thereby reducing resource waste and time consumption caused by blind search; then the quality of the searched signal is judged, and when the conditions are met, the exhaustive beam search algorithm is switched to further determine the best beam, and the strongest arrival angle is obtained through the best beam and a receiving-end beamforming matrix is ​​generated, and finally, with the help of the beamforming matrix, the receiving-end optical machine is allowed to quickly capture the communication target light spot to establish a laser communication link, thereby completing beamforming and aligning the propagation path within a short delay, quickly locking the communication target, and successfully establishing a high-quality communication link, thereby achieving a complete and efficient connection from signal search to link establishment as a whole, overcoming the limitations of a single communication mode, reducing resource costs, and providing an efficient and feasible solution to wireless communication problems.

[0034] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which:

[0036] Figure 1 A flow chart of a laser communication method based on omnidirectional microwaves provided in an embodiment of the present disclosure is shown;

[0037] Figure 2 A schematic diagram of an exemplary adaptive hierarchical beam search provided by an embodiment of the present disclosure is shown;

[0038] Figure 3 A design principle diagram of an exemplary beam search module provided by an embodiment of the present disclosure is shown;

[0039] Figure 4 An exemplary 1-bit quantized A / D beam scanning scenario diagram provided by an embodiment of the present disclosure is shown;

[0040] Figure 5 A schematic diagram showing an exemplary operating environment in which embodiments of the present disclosure can be implemented;

[0041] Figure 6 A block diagram of an omnidirectional microwave-based laser communication device according to an embodiment of the present disclosure is shown;

[0042] Figure 7A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0044] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0045] In response to the problems mentioned in the background technology, the present disclosure provides a laser communication method, device, equipment and storage medium based on omnidirectional microwaves.

[0046] Specifically, based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning using a preset multi-layer beam codebook to search for the microwave signal of the communication target; the quality of the searched signal is judged, and if it is greater than a preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the optimal beam, and the strongest arrival angle is obtained based on the optimal beam and a corresponding beamforming matrix is ​​generated; the beamforming matrix is ​​sent to the optical machine so that the optical machine can quickly capture the communication target light spot, complete alignment, and establish a laser communication link with the communication target for laser communication.

[0047] In this way, beamforming, propagation path alignment, and rapid locking of communication targets can be completed at low cost and short delay, thereby successfully establishing a high-quality communication link. The overall process from signal search to link establishment is complete and efficient, while overcoming the limitations of a single communication method.

[0048] The omnidirectional microwave-based laser communication method provided by the present disclosure is further described below with reference to the accompanying drawings and specific embodiments.

[0049] Figure 1 FIG. 1 is a flow chart showing a laser communication method based on omnidirectional microwaves provided in an embodiment of the present disclosure; Figure 1 As shown, the omnidirectional microwave-based laser communication method 100 may include the following steps:

[0050] S110, based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning using a preset multi-layer beam codebook to search for microwave signals of a communication target.

[0051] Based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning according to the preset starting layer using a preset multi-layer beam codebook. The main path direction of the millimeter wave channel at the receiving end is determined by searching the pilot signal at the transmitting end.

[0052] S120, judging the quality of the searched signal, if it is greater than a preset threshold, switching to an exhaustive beam search algorithm to perform a refined search, determine the best beam, obtain the strongest arrival angle based on the best beam and generate a corresponding beamforming matrix.

[0053] GLRT is used to test the quality of the searched signal and determine whether the quality of the currently searched signal is greater than the preset threshold. If so, the hierarchical scanning is stopped and the exhaustive beam search algorithm is switched to perform a refined search. The best beam is determined through the exhaustive beam search, and the strongest arrival angle is obtained based on the best beam and the corresponding beamforming matrix is ​​generated.

[0054] Further, using GLRT to check the quality of the searched signal to determine whether the quality of the currently searched signal is greater than a preset threshold includes:

[0055] The searched pilot signal is subjected to matched filtering, and the matched filtering output is provided with a target signal-to-noise ratio threshold value and a likelihood ratio threshold value, and a GLRT test problem is constructed based on the target signal-to-noise ratio threshold value and the likelihood ratio threshold value;

[0056] Generate a test statistic expression based on the GLRT test problem, use the test statistic expression to calculate the statistic, and compare the calculated statistic with the likelihood ratio threshold z value to determine whether the SNR (Signal-to-Noise Ratio) of the matched filter output of the beam is higher than the preset target SNR value.

[0057] The exhaustive beam search algorithm is first described in detail below in conjunction with specific embodiments.

[0058] The transmitter Tx selects an omnidirectional antenna from the antenna array to send a unique unmodulated frequency tone to the receiver Rx: ; Among them, f k is the single carrier frequency, t represents time, ; For the strongest arrival angle (AoA) estimation, if the conditions are met: , then the difference in AoA estimation using different tones can usually be ignored, where f c is the system carrier frequency, the passband received signal at Rx by Tx Given by:

[0059] ;

[0060] in, is an adjustable parameter; is the main channel gain vector from Tx to Rx; is the auxiliary channel gain vector from Tx to Rx; Z Rx represents the thermal noise at the receiving antenna array, where , is the noise variance at each antenna at the receiving end. To facilitate the estimation of AoA, a linear search is performed in the angle domain from 0° to 180°, and the angle search step is , therefore, the AoA detection matrix Include column vector; typically, minimum search steps The typical value of depends on the actual number of antennas M used for the AoA search, in particular , the i-th vector Represents the strongest arrival angle of Tx at Rx. The specific formula can be shown as follows:

[0061] ;

[0062] in, is the assumed AoA and For the AoA estimation at the transmitter, the arrival angle detection matrix associated with the transmitter is implemented in the M phase shifters connected to the Kth RF chain .

[0063] The local oscillator (LO) of the RF chain at the receiving end generates the same carrier frequency and down-converts the received signal to baseband. After down-conversion, the signal will be filtered by a low-pass filter, which can remove tones of other frequencies. The equivalent signal of the i-th strongest arrival angle from Tx to Rx is shown below:

[0064] ;in, for The transpose of .

[0065] The strongest angle of arrival, that is, the observed The optimal arrival angle in the directions is:

[0066] ;

[0067] is considered as the strongest arrival angle in Tx; in addition, the estimation of the strongest arrival angle can be performed by using a series of analog comparators in the analog domain or a digital buffer in the digital domain, using The maximum arrival angle in is used to design the simulated beamforming vector of the transmitter at the receiving end. The arrival angle of the uplink obtained from the corresponding transmitted signal at the receiving end can also be estimated at the same time. For simplicity, the simulated beamforming matrix at the receiving end is expressed as follows:

[0068] ;

[0069] The receiver uses an analog beamforming matrix A unique frequency tone is sent to the transmitter, and the AoA of the downlink is estimated at the transmitter. This AoA information will be used to design the analog beamforming vectors used at the transmitter. The signal received at the transmitter It can be expressed as:

[0070] ;

[0071] In the formula, is the main channel gain matrix; is the conjugate of the main channel gain vector; for The transpose of is the gain matrix of the auxiliary channel; for The transpose of Z MS represents the thermal noise at the transmitting antenna array, , is the noise variance of all transmitters.

[0072] Implementing the AoA detection matrix at the transmitter on the phase shifter at the transmitter It also includes The estimated column vector, the matrix of the transmitter The vector of the i-th column is , is given by:

[0073] ;

[0074] In the formula, , is the i-th strongest arrival angle at the transmitter; similarly, the equivalent signal received at the transmitter at the i-th strongest arrival angle from the receiver to the transmitter is as follows:

[0075] ;in, for The conjugate transpose of .

[0076] Likewise, in The maximum value is found between the observation directions, and the simulated beamforming vector is designed according to the estimated value of the arrival angle of the transmitter. The beamforming vector of the transmitter is given by the following formula:

[0077] ;

[0078] The analog beamforming matrix at the transmitter can be expressed as follows:

[0079] .

[0080] Figure 2 A schematic diagram of an exemplary adaptive hierarchical beam search provided by an embodiment of the present disclosure is shown.

[0081] The following is combined with Figure 2 The adaptive hierarchical search algorithm is described in detail in the specific embodiments.

[0082] Assume that there are N adaptive hierarchical search transmitters Tx t There are N antennas and N receivers Rx. r root antenna; during the search process, Tx uses a fixed beam that can cover all directions of the transmitter to send a pilot signal, and Rx uses a preset multi-layer beam codebook for spatial scanning. The main path direction of the millimeter wave channel at the Rx end is determined by the measured pilot signal. After the optimal interval is determined, a detailed search is performed in the interval to obtain the corresponding angle.

[0083] In the initial search phase, Tx uses a beam that can cover all directions of the first communication end to send a pilot signal. In order to achieve omnidirectional coverage, this initial beam can be a beam pattern with a wider angle range. If the transmit beam pattern is represented as W0 (this is an N t ×1), the values ​​of its elements are set according to the requirements of omnidirectional coverage. For example, for a uniform linear array antenna, in order to achieve omnidirectional coverage in the horizontal direction, the phase difference between adjacent antennas can be set to zero, so that the beam is evenly distributed in the horizontal direction; the amplitude of the weight vector can be normalized according to requirements such as transmit power.

[0084] Assume the pilot signal is S p (t), the transmitted signal x(t) after passing through the antenna array of the first communication end can be expressed as x(t)=W0S p (t), this signal will propagate in space and be searched by the second communication end Rx. At the same time, the duration of sending the pilot signal is T p Parameters such as the period and the time period also need to be considered. p It can be determined based on the coherence time of the channel and the time required to scan a layer of beams to ensure that the second communication end can receive a complete pilot signal during different beam scanning processes.

[0085] Define K as the number of codebook layers of Rx, where K>1, and the number of beams in the Kth layer is L K Satisfaction: L K =2 K , K=1, ...K; the receiver Rx starts searching from layer K=1, and its search space is After the search on the Kth layer is completed, Rx reduces the search range on the k+1th layer by half according to the signal obtained by beam scanning, that is, , , because l k =2 K , so the number of beams that need to be searched in the K+1th layer is l K+1 =2 k / 2=2 k-1 , we can further obtain the total number of beams that Rx needs to search by summing the geometric series: 2 K-1 , specifically, the schematic diagram of beam layered search is as follows Figure 2 shown.

[0086] Rx only needs to search two beams at each layer, is the beam vector scanned by Rx at the Kth layer, and then let w t is the beam vector used by Tx, then the equivalent channel corresponding to the two beam combinations of the Kth layer can be expressed as: , ; Where H is the channel matrix of the system.

[0087] The pilot signal corresponding to m scans is expressed as , where n k is the number of symbol periods used by Rx to scan a single beam each time; the pilot symbols collected by Rx can be expressed as:

[0088] ;

[0089] in The mean is 0 and the variance is Additive complex Gaussian noise.

[0090] The pilot signal after matched filtering can be expressed as:

[0091] ;

[0092] in, .

[0093] Matched filter signal Is an equivalent channel The sufficient statistics are used to determine whether to stop scanning. If scanning is stopped, Rx can determine the search range of the K+1th layer based on the matched filter signal; the specific method is as follows:

[0094] When the scan time is long enough When the signal-to-noise ratio is higher than the preset signal-to-noise ratio, Rx can The strength of the two beams can accurately determine the strength relationship of the channels corresponding to the two beams, thereby determining the direction range of the main path of the channel. For example, when the main path of the channel falls on the beam Within the coverage area, .

[0095] The generalized likelihood ratio test (GLRT) can be used to determine the matched filter signal. The signal-to-noise ratio is high enough. When the target SNR value is reached, Rx stops scanning the current layer and determines the beam search range of the next layer. When it is the last layer, the final angle range is determined.

[0096] In the proposed GLRT test, the matched filter output of the received signal has a target signal-to-noise ratio threshold , and the likelihood ratio threshold ; When the received signal matched filter output SNR is greater than the signal-to-noise threshold, denoted as H0, and less than the signal-to-noise ratio threshold, denoted as H1, the hypothesis test problem at this time is expressed as:

[0097] ;

[0098] Using the GLRT method, the test statistic can be written as:

[0099] ;

[0100] in, , is the likelihood function under H0 and H1. After calculation, the statistic It can be expressed as:

[0101] ;

[0102] When the test statistic When , the SNR of the matched filter output of the beam is judged to be higher than the preset target SNR value, otherwise, it is judged to be lower than the target SNR value; when searching at the Kth layer, if the beam satisfies the following relationship:

[0103] ; then the scanning of the Kth layer is terminated, otherwise, the scanning is continued repeatedly.

[0104] After stopping the search at the Kth layer, Rx needs to determine the search range at the K+1th layer. The search range at the K+1th layer can be determined as follows: Figure 2As shown, C1 and C2 represent beam , Coverage range, C3 represents the beam and The intersection is the center and the angle interval with C1 and C2 of equal width; C1, C2, and C3 are all used as possible search angle intervals for the next layer. When the channel direction falls on the intersection of two receiving beams, C3 is used as the angle interval to be searched in the next layer.

[0105] The millimeter wave single-path channel can be approximately written as , where α represents the path gain; represents the antenna direction vector at Rx, , that is, the vector Belongs to the complex domain N t ×1-dimensional vector space, It is a r A column vector of complex elements; for The conjugate transpose of represents the antenna direction vector at Tx, , that is, the vector Belongs to the complex domain N t ×1-dimensional vector space, It is a t A column vector of complex elements.

[0106] The antenna direction vector of a uniform linear array with half-wavelength antenna spacing can be expressed as: ; Where N represents the number of antennas in the antenna array, represents the receiving angle / transmitting angle (AOA / AOD); the effective channel strength can be expressed as:

[0107] ;

[0108] in, represents the Tx beamforming gain, where W TX is the beamforming weight vector;

[0109] represents the Rx beamforming gain, for The conjugate transpose of ;

[0110] make , the received signal after matched filtering can be rewritten as:

[0111] ;

[0112] in, The mean is 0 and the variance is Additive complex Gaussian noise; two receive beams at the Kth layer at the transmitter , The two signals received , The mean is ,variance The complex Gaussian distribution of and are independent of each other; the path direction Φ can be obtained by the maximum likelihood detection method, and its likelihood function can be written as:

[0113] ;

[0114] make , it can be seen that the maximum value of the received signal likelihood function is equivalent to Get the minimum value; for any Φ, when , The minimized value can be obtained; where:

[0115] ;

[0116] in, express The conjugation of.

[0117] Through the above operation, the search angle interval of each layer is divided into three intervals, so the central angle value of the three intervals is selected as the candidate value of Φ to minimize ,Right now ,like Figure 2 As shown, Respectively The angle of the main lobe direction, express The angle of the intersection, then the central angle of the K+1th layer to be searched interval is: .

[0118] when When Coverage As the search interval of the next layer of beam search; when When Coverage As the search interval for the next layer of beam search;

[0119] when When as the center, and The angle interval of the same width is used as the beam search interval of the next stage, which is equivalent to Move half the coverage width; the method for selecting the next layer of beam search interval can be expressed as:

[0120] ;

[0121] When searching for the last layer of layered beams, you need to select the final beam direction. Rx can choose As the final beam direction used, its corresponding beam vector is:

[0122] ;

[0123] in, is any codeword vector in the K-th level codebook, represents the Hadamard product, express and The angle difference between the main lobe directions; when When , the selected beam direction is The main lobe direction is .

[0124] After the optimal interval is determined, a detailed search is performed in the interval, that is, the exhaustive search method described above is used to obtain the angle corresponding to the transmitting end. Based on the angle corresponding to the transmitting end, the beamforming matrix at the receiving end is obtained. The specific search principle and process are the same as above and will not be described in detail here.

[0125] Figure 3 A design schematic diagram of an exemplary beam search module provided in an embodiment of the present disclosure is shown.

[0126] In this exemplary Simulink model, the design schematic of the beam search module can be as follows: Figure 3 As shown:

[0127] IN1 is the orthogonal pilot signal Pilots (dftmtx(N).') transmitted by the transmitter.

[0128] IN2 is the input Rician K-factor parameter, denoted as k.

[0129] IN3 is the initial angle matrix transmitted from the transmitter to the receiver, denoted as theta_LOS_BS.

[0130] BeamSearch is a beam search module; this module mainly includes two search algorithms: exhaustive beam search and adaptive hierarchical beam search. The program gives an exemplary Rician K-factor parameter (denoted as k) with a decision threshold of 30, that is, when the Rician factor k is less than the decision threshold, exhaustive beam search is used; when the Rician factor k is greater than or equal to the decision threshold, adaptive hierarchical beam search is used; the determination of the decision threshold has been shown above and will not be repeated here.

[0131] OUT1 outputs the beamforming matrix corresponding to the strongest arrival angle of the receiving end obtained through beam search, which is recorded as H_Los_BS.

[0132] According to the embodiments of the present disclosure, based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning according to a preset starting layer through a preset multi-layer beam codebook to determine the main path direction of the millimeter wave channel at the receiving end, which gives full play to the advantages of the millimeter wave system working in a complex environment. Through orderly and targeted searches, it is possible to focus on the possible main propagation path more efficiently in a large spatial range. At the same time, a switching condition is set to switch the exhaustive beam search algorithm at an appropriate time, thereby avoiding continuing to waste resources for possibly invalid hierarchical scanning when the signal quality is poor, saving time and hardware resource overhead, and switching to the exhaustive beam search algorithm at the right time. On the basis of overcoming the difficulties of large-space short-delay beamforming in millimeter wave communication, the angle of the transmitter (i.e., the communication target) can be obtained more accurately, and a beamforming matrix that is more in line with the actual propagation path and more helpful in overcoming path loss is generated, thereby effectively improving the success rate of establishing a communication link and improving the communication quality, and enhancing the adaptability and target locking capability of the entire communication system in harsh environments.

[0133] S130, sending the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot, complete the alignment, and establish a laser communication link with the communication target for laser communication.

[0134] Specifically, the beamforming matrix is ​​format converted and parsed, and the parsed information is sent to the optical machine through a compatible interface, so that the receiving optical machine drives related devices to make adjustments according to the parsed information, so as to quickly capture the communication target light spot, complete alignment, and establish a laser communication link with the communication target for laser communication.

[0135] Assume that in a microwave communication system, the beamforming matrix is ​​stored in a digital signal processor DSP in the form of a complex matrix, and each element is represented as a combination of a real part and an imaginary part, which is used to control the signal weighting of the microwave antenna array. The input format required by the optomechanical system is based on the separation of amplitude and phase, and the data type is a specific floating point format; read the complex data of the beamforming matrix from the DSP, extract the real part and imaginary part of each matrix element, and calculate the corresponding amplitude and phase; the calculation formula can be as follows:

[0136] .

[0137] The calculated amplitude and phase values ​​are encoded in the floating-point format required by the optical machine system and stored in a new data structure to complete the format conversion. After receiving the converted format data, the control system of the optical machine starts parsing; for the amplitude data, it is directly used to control the attenuation of the optical attenuator inside the optical machine; (for example, if the amplitude value is large, it means that the beam energy in this direction is strong, and the optical machine can reduce the attenuation of the optical attenuator accordingly to ensure that the signal strength is within the appropriate range.) For the phase data, it is used to control the phase modulator, and the phase of the laser beam passing through the phase modulator is adjusted according to the phase value, thereby realizing the control of the beam direction; (for example, if the phase value indicates that the beam needs to be deflected to the left by a certain angle, the optical machine adjusts the parameters of the phase modulator to make the laser beam undergo a corresponding phase change during the propagation process, thereby realizing the deflection of the beam and completing the alignment and communication with the communication target.)

[0138] As another embodiment, consider another situation. In a beamforming system based on the 5G communication standard, the beamforming matrix is ​​stored and transmitted in the format specified by the 5G protocol, where the encoding method of the matrix elements, the order of data arrangement, etc. are all designed to meet the needs of 5G communication.

[0139] In this case, first parse the header information of the beamforming matrix in the 5G format to determine the basic information such as the matrix dimension and data type, then read the matrix elements in element order, and for each element, convert it into the original value according to the decoding rules of the 5G format, and then re-encode it according to the encoding method required by the optical machine; for example, the 5G format may use compressed encoding to store matrix elements, while the optical machine requires direct binary value representation, which requires decompression and re-encoding operations.

[0140] The converted elements are stored in a new memory area in the matrix storage order required by the optical machine, forming a beamforming matrix that conforms to the optical machine format and parsing it to obtain the relevant information of each element in the matrix, and the relevant information of each element is sent to the optical machine through a compatible interface; for the relevant information of each element in the matrix, the optical machine applies it as a weight factor to the transmission signal processing flow.

[0141] For the optical attenuator, the amplitude-related information presented in the weight factor will be interpreted by the optical machine to control the attenuation degree of the optical attenuator. If the amplitude value is large, it means that the energy of the light beam in that direction is expected to be stronger. The optical machine will reduce the attenuation of the optical attenuator accordingly to ensure that the light beam has enough energy to cover the target area, helping to find and align the communication target light spot.

[0142] The deformable mirror will also make corresponding deformation adjustments based on the comprehensive information contained in the received weight factors. By changing the curved shape of the mirror, the laser beam can be finely reshaped in angle and shape, further optimizing the pointing accuracy of the beam, allowing the light spot to fall more accurately on the receiving element of the optical machine, or allowing the emitted light beam to be more accurately aimed at the communication target, completing the precise alignment operation.

[0143] After completing the above-mentioned spot capture and alignment work, the optical machine and the communication target will negotiate the communication parameters. The two parties will exchange information through a pre-set communication protocol to determine key communication parameters such as laser wavelength, power, modulation method, and data rate. After several signal interactions, the two parties may determine to use a specific wavelength of laser, set the power to a suitable value, use intensity modulation, and agree on the amount of data transmitted per second.

[0144] Subsequently, preliminary laser communication link testing will be carried out. The optical machine will send a test signal to the communication target, such as a pseudo-random sequence signal that is easy to detect and analyze. After receiving the test signal, the communication target will send back a corresponding feedback signal. Both parties will evaluate the link quality based on the received signal, focusing on key indicators such as signal-to-noise ratio and bit error rate.

[0145] If the bit error rate is found to be too high or the signal-to-noise ratio is not ideal during the test, the optical machine will fine-tune the relevant internal optical devices again based on the feedback information, and may further adjust the transmission power, optimize the phase modulation, or change the attenuation of the optical attenuator, so as to improve the communication quality of the link and ensure that the communication link reaches the expected stable and reliable state.

[0146] After the above series of preparations, adjustments and tests, a stable laser communication link can be formally established, and regular laser communication activities such as data transmission can be started. In the subsequent communication process, the optical machine will continue to monitor the link quality, and dynamically adjust its own device parameters according to the actual environmental changes and communication status to ensure continuous, stable and efficient laser communication.

[0147] According to an embodiment of the present disclosure,

[0148] By adaptively processing the beamforming matrix and transmitting it to the optical machine, the optical machine can drive related devices to make adjustments based on the analyzed information, and then quickly and accurately capture the communication target light spot and complete the alignment to establish a laser communication link. It connects the beamforming link of millimeter wave communication and the calibration link of laser communication, and fully utilizes the advantages of laser communication such as high precision and large amount of information collection, and makes up for the shortcoming of its long calibration time. At the same time, with the help of the millimeter wave system's strong fog and smoke penetration capabilities, it achieves the goal of efficiently establishing communication links in different weather environments, and improves the comprehensive ability of the entire communication system to carry out high-quality communications in complex environments.

[0149] In some embodiments, the omnidirectional microwave-based laser communication method 100 further includes:

[0150] A 1-bit quantized A / D operation is performed on the searched microwave signal, and the probability of each beam becoming the best beam is calculated through n-fold Bernoulli distribution and the threshold value of the quantization function to generate the best beam detection probability matrix. Based on the best beam detection probability matrix, the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix.

[0151] A 1-bit quantized A / D operation is performed on the emitted microwave signal so that the communication target can perform a 1-bit quantized A / D operation on the searched microwave signal, and the probability of each beam becoming the best beam is calculated through n-fold Bernoulli distribution and the threshold value of the quantization function to generate an optimal beam detection probability matrix. Based on the optimal beam detection probability matrix, an adaptive hierarchical beam search algorithm and an exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate a corresponding beamforming matrix.

[0152] It can be understood that when the conditions of a single hardware are limited, both communicating parties can perform 1-bit quantized A / D operations on the transmitted / received signals, and combine the n-fold Bernoulli distribution and the threshold value of the quantization function to calculate the probability of each beam in the received signal becoming the best beam, and generate the best beam detection probability matrix according to the probability of each beam becoming the best beam; based on the best beam detection probability matrix, the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix.

[0153] In the above-mentioned millimeter wave communication beam search process, a large number of high-precision A / Ds will be used, resulting in huge hardware overhead. Figure 4 The specific embodiments further illustrate how to obtain search results at the minimum cost when single hardware resources are limited.

[0154] Figure 4 An exemplary 1-bit quantized A / D beam scanning scenario diagram provided by an embodiment of the present disclosure is shown.

[0155] like Figure 4 As shown, when the transmitter Tx is along the uplink channel h K Send signal s to the receiving end Rx K ( , f K is the carrier frequency of the transmitted signal, t is the time), the antenna array at the receiving end will periodically scan the signal from the transmitting end K, and the transmitting end K will perform a 1-bit quantized A / D operation on the transmitted signal when the signal is sent. The 1-bit quantized A / D operation will also be performed to obtain the final receiving signal , the receiving end can Combining the heavy Bernoulli distribution with the threshold of the quantization function , the probability of each beam at the receiving end becoming the best beam is calculated, and the best beam detection probability matrix Ω is generated according to the probability of each beam becoming the best beam.

[0156] like Figure 4 As shown, the detailed beam search process of 1-bit quantized A / D can be described as follows:

[0157] At the receiving end, the transmitted signal s from the transmitting end K K After periodic scanning, the signal s transmitted by the transmitter K can be obtained. K The received signal at the BS for:

[0158] ;

[0159] in, is the thermal noise generated at the receiving antenna array, , is the noise variance of each antenna array at the receiving end; the strongest arrival angle of the transmitting end at the receiving end can be obtained through the received signal from the transmitting end K, and the strongest arrival angles of all transmitting ends are combined to form the strongest arrival angle matrix of the receiving end. The strongest arrival angle matrix can be used to obtain the simulated beamforming matrix of the receiving end following the M+1 beam fixed codebook for:

[0160] ;

[0161] in, is the strongest arrival angle obtained by the transmitter K along the i-th path at the receiving end , μ is limited by , , the received signal at the receiving end can be obtained for:

[0162] ;

[0163] In this embodiment, it is assumed that an ideal automatic gain control (AGC) is used in the communication system. The AGC can give different gains to different signals from the transmitter, thereby ensuring that the output amplitudes of the signals received by the receiver are all at the same standard. On the basis of using the ideal AGC, both the transmitter and the receiver are equipped with low-precision A / D. The signal after the 1-bit quantization A / D at the transmitter is for:

[0164] ;

[0165] in, It is a 1-bit quantization operation on the signal at the transmitting end.

[0166] The receiving end receives the signal after 1-bit quantization A / D for:

[0167] ;

[0168] in, It is to perform a 1-bit quantization operation on the received signal at the receiving end.

[0169] The received signal of the hardware-limited 1-bit quantized A / D is obtained at the receiving end Afterwards, an n-fold Bernoulli distribution is introduced for the received signal, making The probability mass function is The n-fold Bernhardt distribution requires:

[0170] (1) There are only two possible outcomes in each trial (or);

[0171] (2) The occurrence or non-occurrence of the two results is mutually exclusive and independent, and has nothing to do with the results of other tests;

[0172] (3) The probability of an event occurring or not remains constant in each independent trial.

[0173] At the same time, the probability mass function of the n-fold Bernoulli distribution satisfies the above three points for:

[0174] ;

[0175] Where, is the possible result of n-fold Bernoulli distribution, r=1 or r=0; n is the total number of experiments; p is the probability of occurrence (experimental result r=1) in an experiment; p i is the probability of (experimental result r=1) occurring in n experiments; q i is the probability that the result r = 0 does not occur in n experiments.

[0176] Combining the above two equations, we can get The simplified representation is:

[0177] ;

[0178] in, To quantize the threshold value, different quantization threshold values ​​will affect the acquisition of the best beam. Through experiments, the best quantization threshold value is designed to improve the accuracy of the best beam acquisition.

[0179] Based on the above formula, we can get L observation values ​​of the received signal after 1-bit quantization A / D: , the observation value can be theoretically divided into two parts, respectively using the set and Indicates, specifically:

[0180] ;

[0181] ;

[0182] Where L is the number of repeated detections, initialized to L=0; K is the number of times the quantized value of the received signal is 1 after L detections, initialized to K=0; Based on the above observation value of the received signal, the detection probability value of the i-th beam at the receiving end as the best beam can be obtained for:

[0183] ;

[0184] in, It is unbiased. Unbiased means that when the difference between the statistical mean and the true value of the statistic is 0, the statistic is unbiased and is an unbiased estimate; when the difference between the statistical mean and the true value of the statistic is not 0, the statistic is biased and is a biased estimate; when the statistical mean of a statistic tends to the true value as the number of repeated tests L increases, the statistic is asymptotically unbiased and is an asymptotically unbiased estimate; the above process can be recorded as:

[0185] ;

[0186] in, for The truth value of for The statistical mean of yes The difference between the statistical mean and the true value; From the above formula, we can get: When and .

[0187] After all M+1 beams at the receiving end are periodically scanned, the optimal beam detection probability matrix Ω based on the full antenna array can be obtained at the receiving end as follows:

[0188] ;

[0189] in, is the probability that the first beam at the receiving end is the best beam in n experiments; is the probability that the M+1th beam at the receiving end is the best beam in n experiments.

[0190] In order to facilitate the observation of the best beam, the best beam detection probability matrix Ω can be sorted in descending order to obtain Ω d :

[0191] ;

[0192] in, is the probability that the first beam at the receiving end is the best beam in the n experiments after sorting in descending order; is the probability that the M+1th beam at the receiving end is the best beam in the n experiments after descending sorting; for any i, the above formula has .

[0193] After obtaining the best beam detection probability matrix ranking table, the area where the beam with the highest detection probability in the ranking table is located is selected as the initial search area of ​​the adaptive hierarchical beam search algorithm for hierarchical search.

[0194] If the best beam in the area is found to be the same as the best beam in the area in the best beam detection probability matrix and the signal quality is greater than a preset threshold, the strongest arrival angle is directly obtained based on the best beam and a corresponding beamforming matrix is ​​generated.

[0195] If after searching, it is found that the best beam in the area is different from the best beam in the area in the best beam detection probability matrix but the signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam and generate the corresponding beamforming matrix.

[0196] If after searching, it is found that the best beam in the area is different from the best beam in the area in the best beam detection probability matrix, and the signal quality of the best beam is less than the preset threshold, then the hierarchical search is continued until the quality of the searched signal is greater than the preset threshold, and the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam, and generate the corresponding beamforming matrix.

[0197] According to the embodiments of the present disclosure, the obstacles to the integrated communication system caused by insufficient hardware are overcome, the adaptability and robustness of the entire communication system under different hardware conditions are improved, and it is ensured that the integrated application of millimeter wave communication and laser communication can smoothly achieve the establishment of high-quality communication links in various practical scenarios.

[0198] Figure 5 A schematic diagram of an exemplary operating environment in which embodiments of the present disclosure can be implemented is shown; Figure 5 As shown in the figure, taking satellite-to-ground communication as an example, an adaptive hierarchical beam search algorithm is used to gradually narrow the search range according to the multi-layer beam codebook of the ground base station to locate the microwave signal from the satellite; when the signal quality meets the requirements, the exhaustive beam search algorithm is switched to obtain the satellite angle and generate a beamforming matrix, and then the beamforming matrix is ​​sent to the optical machine; the optical machine of the ground base station drives the adjustment of related devices based on the received information, quickly captures the satellite light spot to complete the alignment, and thus establishes a stable laser communication link for laser communication; this fusion method reduces the blindness of beam search caused by the long distance and large space between the satellite and the ground, and improves the signal search efficiency; it combines the advantages of the millimeter wave system in coping with severe weather and the high precision of the laser system, and overcomes the difficulties of quickly locking the target and establishing a high-quality communication link in satellite-to-ground communication.

[0199] In view of the limited single hardware resources that may exist in satellite-to-ground communications, the communicating parties can selectively add 1-bit quantized A / D operations. In some ground base stations or small satellites in remote areas, the hardware resources are limited. This operation generates the optimal beam detection probability matrix to assist the search algorithm and beamforming matrix generation, which can improve the millimeter-wave beam search efficiency in satellite-to-ground communications with limited resources, reduce costs, and ensure that satellite-to-ground communications can be carried out smoothly under different hardware conditions, thereby improving the adaptability and reliability of the entire satellite-to-ground communication system.

[0200] It should be noted that, in order to clearly describe the laser communication method 100 based on omnidirectional microwaves, the present disclosure mainly describes it from a single end of the receiving end. Those skilled in the art should be able to understand that, as the communicating parties, the transmitting end (communication target) and the receiving end each have the ability to execute each step in the laser communication method 100 based on omnidirectional microwaves.

[0201] According to the embodiments of the present disclosure, the following technical effects are achieved:

[0202] In the present disclosure, an adaptive hierarchical beam search algorithm is used to search for microwave signals of communication targets based on omnidirectional microwave spatial scanning, and target signals are efficiently and targetedly searched in a larger search space, thereby reducing resource waste and time consumption caused by blind search; then the quality of the searched signal is judged, and when the conditions are met, the exhaustive beam search algorithm is switched to further obtain the communication target angle and generate a receiving end beamforming matrix, and finally, with the help of the beamforming matrix, the receiving end optical machine is allowed to quickly capture the communication target light spot to establish a laser communication link, thereby completing beamforming and aligning the propagation path within a short delay, quickly locking the communication target, and successfully establishing a high-quality communication link, thereby achieving a complete and efficient connection from signal search to link establishment, overcoming the limitations of a single communication method, reducing resource costs, and providing an efficient and feasible solution to wireless communication problems.

[0203] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present disclosure is not limited by the order of the actions described, because according to the present disclosure, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present disclosure.

[0204] The above is an introduction to the method embodiment. The following is a further explanation of the scheme disclosed in the present invention through an apparatus embodiment.

[0205] Figure 6 FIG. 4 shows a block diagram of an omnidirectional microwave-based laser communication device according to an embodiment of the present disclosure; Figure 6 As shown, the omnidirectional microwave-based laser communication device 600 may include:

[0206] The first processing module 610 is used to perform spatial scanning based on omnidirectional microwaves and use a preset multi-layer beam codebook using an adaptive hierarchical beam search algorithm to search for microwave signals of a communication target.

[0207] The second processing module 620 is used to judge the quality of the searched signal. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to perform a refined search to determine the best beam, obtain the strongest arrival angle based on the best beam, and generate a corresponding beamforming matrix.

[0208] The third processing module 630 is used to send the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot, complete the alignment, and establish a laser communication link with the communication target for laser communication.

[0209] In some embodiments, the omnidirectional microwave-based laser communication device 600 may further include:

[0210] The fourth processing module is used to perform 1-bit quantization A / D operation on the searched microwave signal, and calculate the probability of each beam becoming the best beam through n-fold Bernoulli distribution and the threshold value of the quantization function, and generate the best beam detection probability matrix; based on the best beam detection probability matrix, assist the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm to quickly obtain the strongest arrival angle and generate the corresponding beam forming matrix; perform 1-bit quantization A / D operation on the emitted microwave signal, so that the communication target performs 1-bit quantization A / D operation on the searched microwave signal, and calculate the probability of each beam becoming the best beam through the repeated Bernoulli distribution and the threshold value of the quantization function, and generate the best beam detection probability matrix; based on the best beam detection probability matrix, assist the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm to quickly obtain the strongest arrival angle and generate the corresponding beam forming matrix.

[0211] Understandably, Figure 6 Each module in the omnidirectional microwave-based laser communication device 600 shown has the function of implementing each step in the omnidirectional microwave-based laser communication method 100 provided in the embodiment of the present disclosure, and can achieve its corresponding technical effect. The specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and for the convenience and conciseness of the description, it will not be repeated here.

[0212] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device and a readable storage medium.

[0213] Figure 7A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown.

[0214] The electronic device 700 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0215] The electronic device 700 includes a computing unit 701, which can perform various appropriate actions and processes according to a computer program stored in a ROM 702 or a computer program loaded from a storage unit 708 into a RAM 703. In the RAM 703, various programs and data required for the operation of the electronic device 700 can also be stored. The computing unit 701, the ROM 702, and the RAM 703 are connected to each other via a bus 704. An I / O interface 705 is also connected to the bus 704.

[0216] Multiple components in the electronic device 700 are connected to the I / O interface 705, including: an input unit 706, such as a keyboard, a mouse, etc.; an output unit 707, such as various types of displays, speakers, etc.; a storage unit 708, such as a disk, an optical disk, etc.; and a communication unit 709, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 709 allows the electronic device 700 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0217] The computing unit 701 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 701 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 701 performs the various methods and processes described above, such as method 100. For example, in some embodiments, the method 100 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 708. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 700 via the ROM 702 and / or the communication unit 709. When the computer program is loaded into the RAM 703 and executed by the computing unit 701, one or more steps of the method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 701 may be configured to perform the method 100 in any other appropriate manner (e.g., by means of firmware).

[0218] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0219] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0220] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0221] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0222] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0223] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0224] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0225] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A laser communication method based on omnidirectional microwaves, applied to a communication system, characterized in that: The method comprises: Based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning using a preset multi-layer beam codebook to search for microwave signals of communication targets; The quality of the searched signal is judged. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to refine the search, determine the best beam, obtain the strongest arrival angle based on the best beam, and generate the corresponding beamforming matrix; Send the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot and establish a laser communication link with the communication target; Also includes: Perform 1-bit quantization A / D operation on the searched microwave signal to generate the optimal beam detection probability matrix; Based on the optimal beam detection probability matrix, the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix; including: The optimal beam detection probability matrix is ​​sorted, and the area where the beam with the highest detection probability in the sorted table is located is used as the initial search area of ​​the adaptive hierarchical beam search algorithm; If after the search, the best beam in the area is the same as the best beam in the probability matrix and the signal quality is greater than the preset threshold, the strongest arrival angle is directly obtained based on the best beam and a beamforming matrix is ​​generated; if after the search, the best beam in the area is different from the best beam in the probability matrix but the signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to refine the search, the best beam is determined, the strongest arrival angle is obtained based on the best beam, and a beamforming matrix is ​​generated; if after the search, the best beam in the area is different from the best beam in the probability matrix, and the signal quality of the best beam is less than the preset threshold, the hierarchical search is continued until the searched signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to refine the search, the best beam is determined, the strongest arrival angle is obtained based on the best beam, and a beamforming matrix is ​​generated; The beamforming matrix is ​​sent to the optical machine so that the optical machine can quickly capture the communication target light spot and establish a laser communication link with the communication target.

2. The method according to claim 1, characterized in that The method is based on omnidirectional microwaves and uses an adaptive hierarchical beam search algorithm to perform spatial scanning using a preset multi-layer beam codebook to search for microwave signals of a communication target, including: Based on omnidirectional microwaves, an adaptive hierarchical beam search algorithm is used to perform spatial scanning according to the preset starting layer using a preset multi-layer beam codebook. The main path direction of the millimeter wave channel at the receiving end is determined by searching the pilot signal at the transmitting end.

3. The method according to claim 1, characterized in that: The quality of the searched signal is judged. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to refine the search, the best beam is determined, the strongest arrival angle is obtained based on the best beam, and a corresponding beamforming matrix is ​​generated, including: GLRT is used to test the quality of the searched signal and determine whether the quality of the currently searched signal is greater than the preset threshold. If so, the hierarchical scanning is stopped and the exhaustive beam search algorithm is switched to perform a refined search. The best beam is determined through the exhaustive beam search, and the strongest arrival angle is obtained based on the best beam and the corresponding beamforming matrix is ​​generated.

4. The method according to claim 3, characterized in that The using GLRT to check the quality of the searched signal and judging whether the quality of the currently searched signal is greater than a preset threshold comprises: Performing matched filtering on the searched pilot signal, wherein the matched filtering output is provided with a target signal-to-noise ratio threshold value and a likelihood ratio threshold value, and constructing a GLRT test problem based on the target signal-to-noise ratio threshold value and the likelihood ratio threshold value; A test statistic expression is generated according to the GLRT test problem, and the statistic is calculated using the test statistic expression. According to the comparison result between the calculated statistic and the likelihood ratio threshold value, it is judged whether the SNR of the matched filter output of the beam is higher than the preset target SNR value.

5. The method according to claim 1, characterized in that The step of sending the beamforming matrix to the optical machine so that the optical machine at the receiving end can quickly capture the communication target light spot and establish a laser communication link with the communication target includes: The beamforming matrix is ​​format converted and parsed, and the parsed information is sent to the optical machine through a compatible interface so that the receiving optical machine can drive related devices to make adjustments based on the parsed information, so as to quickly capture the communication target light spot, complete alignment, and establish a laser communication link with the communication target for laser communication.

6. The method according to claim 1, characterized in that The method further comprises: A 1-bit quantized A / D operation is performed on the emitted microwave signal so that the communication target can perform a 1-bit quantized A / D operation on the searched microwave signal, and the probability of each beam becoming the best beam is calculated through n-fold Bernoulli distribution and the threshold value of the quantization function to generate an optimal beam detection probability matrix. Based on the optimal beam detection probability matrix, an adaptive hierarchical beam search algorithm and an exhaustive beam search algorithm are assisted to quickly obtain the strongest arrival angle and generate a corresponding beamforming matrix.

7. A laser communication device based on omnidirectional microwaves, applied to a communication system, characterized in that: The device comprises: The first processing module is used to perform spatial scanning based on omnidirectional microwaves using an adaptive hierarchical beam search algorithm and a preset multi-layer beam codebook to search for microwave signals of a communication target; The second processing module is used to judge the quality of the searched signal. If it is greater than a preset threshold, the exhaustive beam search algorithm is switched to refine the search, determine the best beam, obtain the strongest arrival angle based on the best beam, and generate a corresponding beamforming matrix; The third processing module is used to send the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot and establish a laser communication link with the communication target; Also includes: The first processing module is used to perform 1-bit quantized A / D operation on the searched microwave signal to generate an optimal beam detection probability matrix; The second processing module is used to assist the adaptive hierarchical beam search algorithm and the exhaustive beam search algorithm based on the optimal beam detection probability matrix to quickly obtain the strongest arrival angle and generate the corresponding beamforming matrix; including: The optimal beam detection probability matrix is ​​sorted, and the area where the beam with the highest detection probability in the sorted table is located is used as the initial search area of ​​the adaptive hierarchical beam search algorithm; If after the search, the best beam in the area is the same as the best beam in the probability matrix and the signal quality is greater than the preset threshold, the strongest arrival angle is directly obtained based on the best beam and a beamforming matrix is ​​generated; if after the search, the best beam in the area is different from the best beam in the probability matrix but the signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to refine the search, the best beam is determined, the strongest arrival angle is obtained based on the best beam, and a beamforming matrix is ​​generated; if after the search, the best beam in the area is different from the best beam in the probability matrix, and the signal quality of the best beam is less than the preset threshold, the hierarchical search is continued until the searched signal quality is greater than the preset threshold, the exhaustive beam search algorithm is switched to refine the search, the best beam is determined, the strongest arrival angle is obtained based on the best beam, and a beamforming matrix is ​​generated; The third processing module is used to send the beamforming matrix to the optical machine so that the optical machine can quickly capture the communication target light spot and establish a laser communication link with the communication target.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory in communication with the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer-readable storage medium to execute the method according to any one of claims 1-6.

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