Current Issue

• • 2022, Vol. 45 No. 1 Published date:28 February 2022 Last issue Next issue

  PAPERS

  • QoS Routing Algorithm in Clustered Self-Organizing Networks
  • YANG Can, LUO Tao, LIU Ying, LI Zexu, XU Yongqing
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 1-6. DOI:10.13190/j.jbupt.2021-048
  • Abstract ( 890 )     HTML( 445 )     　　
  • Based on the distributed and clustering network architecture, network nodes can be divided into multiple clusters, which can be managed by their corresponding cluster heads in a collaborative manner. In order to achieve on-demand, efficient matches between the differentiated quality of service (QoS) requirements and the multi-dimensional network resources, a reinforcement learning-based routing algorithm is proposed. The proposed algorithm aims to reduce end-to-end delay and prevent congestion by optimizing the routing path, which can be implemented in both centralized cluster heads and distributed nodes, so as to guarantee the robustness in a dynamic environment. The performance is evaluated by numerical simulations in a network with 100 nodes divided into four regions. The simulation results illustrate that the proposed algorithm can reduce average latency significantly. Besides, the algorithm proposed is superior to the minimum-hop method in terms of rejection rate and resource utilization.
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  • High Frequency Broadband Channel Measurement and Large Scale Fading Modeling in Indoor Office Scenario
  • YANG Lihua, LIU Jiahuan, REN Lulu, YANG Qin, HUANG Shanhu
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 7-12. DOI:10.13190/j.jbupt.2021-090
  • Abstract ( 630 )     HTML( 374 )     　　
  • To explore the feasibility of wireless communication in the high-frequency broadband, the large-scale fading characteristics of 9~12GHz in indoor office scenarios are studied. Based on a large amount of measured data, a novel path loss model with shelter loss is proposed for indoor non-line-of-sight scenarios with obstructions. The proposed model uses the shelter loss to compensate the effect caused by the shelter, and the relationship between the shelter loss and the frequency is analyzed. Moreover, the statistical characteristics of the shielding loss under different frequencies are also presented. The experimental results show that the shielding loss and the distance have an exponential function relationship when the shelter is stationary. The convergence speed of the exponential function decreases with the increase of frequency. When the shelter moves, the shielding loss and the distance satisfy a quadratic function relationship, and the position of the least shielding loss locates at the midpoint between the transmitter and the receive antennas as the frequency increases. The proposed model is benefit to the design of the future high-frequency indoor wireless communication system and the network deployment of microcells.
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  • Differential Privacy Trajectory Data Protection Scheme
  • SONG Cheng, XU Biao, HE Junyi
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 13-18. DOI:10.13190/j.jbupt.2021-076
  • Abstract ( 983 )     HTML( 549 )     　　
  • To solve the issue that the trajectory privacy information of current users is easy to be disclosed, a differential privacy trajectory data protection scheme is proposed. Based on the location-based service requesting user identity anonymization process, this scheme adopts differential privacy technology to add noise to the user's trajectory data set to generate the data set with trajectory noise. Then, the dummy user with noise-added trajectory is used to replace the real user to execute the location based service request, thereby realizing the privacy protection of the user's identity, trajectory and query information. Through security analysis, the scheme satisfies the security features of anonymity, unforgeability and anti-counterfeiting attack. The simulation results show that the scheme not only has better data availability, but also has certain advantages in efficiency.
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  • Optimization of Lifts Scheduling for Four-Way Shuttle Systems
  • ZHANG Jingtian, MA Ying, WENG Xun, SUN Zhuangzhi, ZHANG Jilong
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 19-25,81. DOI:10.13190/j.jbupt.2021-069
  • Abstract ( 1167 )     HTML( 907 )     　　
  • As the bottleneck resource of the four-way shuttle systems, the performance of lifts scheduling scheme is closely related to the system operational efficiency. A lifts scheduling strategy is proposed for the lifts scheduling problem. First, the lifts scheduling problem is transformed into a flexible job-shop scheduling problem with transportation time, and a mathematical model is constructed considering the constraints of task sequencing on the same tier. Second, an improved hybrid genetic algorithm is proposed to solve the model, which is based on the hybrid genetic algorithm. Since the hybrid genetic algorithm is easy to produce illegal individuals, leading to the decline of the search ability of the algorithm, an individual correction method is proposed to enhance the search ability of the algorithm. Finally, the feasibility and effectiveness of model and improved hybrid genetic algorithm are verified using the actual data of an agricultural product cold store. The results show that the improved hybrid genetic algorithm can save the task completion time by at least 24.66% compared to the actual applied strategy.
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  • GCL Adaptive Adjustment Algorithm in Time Sensitive Networks
  • ZHOU Xiaoming, QIU Zixin, ZHU Jinyu, ZHANG Hengsheng, ZHAO Chenglin
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 26-32. DOI:10.13190/j.jbupt.2021-117
  • Abstract ( 1042 )     HTML( 850 )     　　
  • Time sensitive networking (TSN) enables applying ethernet technology in mission-critical systems with strict delay constraints.Currently, most TSN deployed on the network is static, and TSN devices cannot respond to topology changes or dynamic changes in traffic. To solve the above problems, the theoretical end-to-end delay of time-sensitive traffic is derived by establishing a gate control list(GCL) model, and a GCL duration adaptive adjustment algorithm is further proposed. According to the IEEE 802.1Qcc standard proposed by the TSN working group, the centralized network controller module is simulated for the dynamic configuration of GCL.The centralized network controller manages the applications running on the network and detects traffic changes, and then dynamically configures the TSN equipment according to the proposed algorithm to ensure the stable and reliable transmission of time-sensitive services when the traffic changes. The simulation results show that, the GCL adaptive adjustment algorithm has more than doubled average delay satisfaction rate of time-sensitive flows compared with the static TSN configuration.
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  • The Inverse Kinematic Analysis of Spatial 1P5R Serial Manipulators Based on The Double Matrix
  • ZHANG Ying, HUANG Qineng, WEI Shimin, LIAO Qizheng
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 33-38. DOI:10.13190/j.jbupt.2021-098
  • Abstract ( 554 )     HTML( 327 )     　　
  • Introducing the double-matrix into the kinematic analysis of serial manipulators, and combined with the four-dimensional rotation matrix, a novel method for the inverse kinematic analysis of spatial 1P5R serial manipulators is proposed. Fourteen kinematic constraint equations for the inverse kinematic analysis are readily obtained by applying the proposed method. A univariate 16th-degree polynomial equation is derived by the linear elimination and Sylvester resultant elimination from the aforementioned fourteen equations. A numerical example and the corresponding 3D configuration based on SolidWorks are provided to verify the correctness. A signficant advantage of the proposed method lies in that 14 inverse kinematic constraint equations can be readily obtained without vector operation and projection operation, and it also provides a new insight for the modeling to the inverse kinematic analysis of other serial manipulators.
  • References | Supplementary Material | Related Articles

  • Corruption Tolerant Localization for Underwater Acoustic Sensor Networks
  • HU Keyong, SONG Xianglin, GONG Xueyao, SUN Zhongwei, SONG Chuanwang
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 39-45. DOI:10.13190/j.jbupt.2021-125
  • Abstract ( 786 )     HTML( 231 )     　　
  • Packet collisions and signal noises may corrupt ranging packets, resulting in distance measurements data missing and degrading localization performance. A packet corruption tolerant localization algorithm is proposed to address this challenge. First, an energy-efficient mechanism is designed to gather inter-node distance measurements and form partially observed square distance matrix (SDM). Then, leveraging the intrinsic low-rank structure of SDM, the reconstruction of true SDM is formulated as a regularized low-rank matrix factorization problem and an improved Newton-Raphson method is designed to optimize the problem. Finally, a multi-dimension scaling technique is applied to localize all the nodes based on the reconstructed SDM. Simulation results demonstrate that the proposed algorithm outperforms the benchmark approaches in terms of localization accuracy, coverage and stability.
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  • Certificateless Identity Authentication Scheme for Internet of Vehicles in Edge Computing Environment
  • PENG Weiping, HAN Ning, SONG Cheng
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 46-51. DOI:10.13190/j.jbupt.2021-070
  • Abstract ( 795 )     HTML( 401 )     　　
  • In order to solve the problem of privacy leakage in the internet of vehicles identity authentication in the current edge computing environment, a new type of internet of vehicles identity authentication scheme is proposed based on bilinear pairing theory. Based on Voronoi diagram, the scheme divides the regional road network and determines the generator coordinates. According to the distance between the generator and the edge node in the area where the vehicle is located and the current load of the edge node, the most suitable edge node is selected for authentication, or it is certified by the cloud edge collaboration technology and the cloud computing center. The scheme uses certificateless authentication method to realize two-way anonymous authentication, and share key generation between vehicles and edge nodes or cloud computing center, vehicles and vehicles. If the authentication process is abnormal, cloud computing center can trace and revoke malicious nodes quickly through the abnormal data. Security analysis verfies that the scheme can satisfy anonymity, unforgeability and traceability. Simulation results show that the proposed scheme can harvest performance in term of computation, communication overhead and rate of arrival.
  • References | Supplementary Material | Related Articles

  • A Ladder-Type Denoising Method
  • WANG Jing, JIANG Zhuqing, MEN Aidong, GUO Xiaoqiang, WANG Zhikang
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 52-57. DOI:10.13190/j.jbupt.2021-103
  • Abstract ( 660 )     HTML( 425 )     　　
  • A ladder-type denoising method is proposed to improve the denoising performance for raw red green blue(RAW) and standard red green blue(sRGB) real-world images. In the first stage, each channel of the noisy image is denoised separately utilizing intra-channel structure information. In the second stage, the inter-channel correlation information of the noisy image is utilized to further denoise the whole image, and the final boosted denoising result is obtained. Error feedback mechanism is introduced to reduce the information loss caused by sampling. Additionally residual dense connection makes features more effective for reuse and propagation; channel attention selectively enhances features with large amount of information and suppress useless features. The proposed method is compared with other denoising algorithms, and the results show that the proposed method achieves 49.55 dB peak signal to noise ratio(PSNR) in RAW images and 39.55 dB PSNR in sRGB images on Darmstadt noise dataset, and 39.52 dB PSNR on cross-channel dataset, which realizes competitive performance in comparison with other denoising algorithms.
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  • A Pseudo-Random Number Generator for Integer Chaotic Map
  • WANG Yong, GONG Jian, WANG Mingyue, JIANG Gongkun
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 58-62. DOI:10.13190/j.jbupt.2021-094
  • Abstract ( 786 )     HTML( 586 )     　　
  • To mitigate the safety issue caused by the loss of precision of the state value of the floating-point number during the iteration, an integer piecewise Logistic map is proposed by integer processing. The proposed method redefines the multiplication operation of the integer utilizing the uniformity of transient data in the finite precision, which makes the output state values of the model having more uniform distribution probability density and ensure its security. Furthermore, a pseudo-random number generator algorithm is proposed. The proposed algorithm combines the one-dimensional cellular automata with the S-box substitution mechanism, which reduces the coupling between state values and improves the complexity of the algorithm. Performance analysis and simulation experimental results show that the integer chaotic map used in the scheme has uniform probability density distribution and complex dynamic behavior, and the pseudo-random sequences generated by the proposed scheme has high complexity, strong security, and good efficiency. Therefore, the proposed scheme has good application prospects in the field of data security.
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  • Open Source 5G Architecture Based on Heterogeneous Computing Acceleration
  • ZHU Zishen, ZHANG Chenyu, WANG Luhan, LU Zhaoming, WEN Xiangming
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 63-68. DOI:10.13190/j.jbupt.2021-092
  • Abstract ( 721 )     HTML( 510 )     　　
  • Aiming at the problem of poor processing performance of open source of the fifth generation of mobile communications system(5G) under general processor, the characteristics of open source 5G are studied and the architecture of heterogeneous computing acceleration is proposed. This proposed architecture separates the upper layer and the physical layer of the air interface protocol stack, and modularizes physical layer functions of the open source 5G. Utilizing the advantages of general processor on processing upper protocol stack, heterogeneous hardware is introduced to accelerate physical layer function modules, which is demanding for computing resources. The concept of heterogeneous physical layer and the algorithm of adaptive allocation of computing resources are introduced into the architecture. Then, the heterogeneous accelerated open source 5G software platform is implemented for the first time based on OpenAirInterface platform. The actual tests of channel codec and modulation modules show that the proposed heterogeneous acceleration architecture can significantly improve the processing performance of physical layer compared with general purpose processor architecture.
  • References | Supplementary Material | Related Articles

  • Traditional Custume Image Semantic Segmentation Based on Improved EMA Unit
  • ZHAO Haiying, ZHU Hui, HOU Xiaogang
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 69-74. DOI:10.13190/j.jbupt.2021-104
  • Abstract ( 760 )     HTML( 433 )     　　
  • The object edge details are difficult to retain due to the confusion of labels and the loss of small objects in traditional clothing image segmentation. To solve the issue, a semantic segmentation network model termed residual expectation maximization attention based on convolution attention feature is proposed. The proposed model first uses ResNeXt-50 as the backbone network for shared features, and introduces a set of parallel convolutional attention modules in the feature extraction stage, which can effectively suppress invalid features and make the features of the target region more prominent. Then, the residual idea is used to optimize the expectation maximization attention unit to avoid the gradient explosion or disappearance in the iterative process, so as to establish the relationship between the positions in the feature map and realize the semantic segmentation model based on saliency fusion learning. Finally, qualitative and quantitative experiments verify the efficiency of the proposed model on the traditional national costume data set. The mean intersection over union segmentation index reaches 83.91%, which achieves the best results among similar algorithms.
  • References | Supplementary Material | Related Articles

  • Perspective-Three-Point Visible Light Localization Algorithm Assisted by Photo-Diode
  • ZHANG Zhitao, GUO Caili, BAI Lin, YU Bei, YANG Yang
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 75-81. DOI:10.13190/j.jbupt.2021-047
  • Abstract ( 661 )     HTML( 325 )     　　
  • The number and orientation of light-emitting diodes (LED) in visible light positioning have a great impact on positioning performance. To circumvent the challenge, a photo diode (PD) assisted perspective-three-point (P3P) algorithm is proposed. The basic idea of the proposed algorithm is to utilize visual information to estimate the incidence angles of visible lights first. Then, estimating the distances between the LEDs and the receiver by typical P3P algorithms, we can obtain up to four solution sets for the distances. Finally, the desired solution set can be determined by strength information, and based on the estimated distances, the position of the receiver can be obtained. Simulation results show that the proposed algorithm can effectively reduce the positioning error caused by LED's tilt. To further verify the performance of the proposed algorithm, a visible light positioning platform is designed and implemented. Experimental results verity that the proposed algorithm can achieve indoor positioning using three LED point light sources when the LEDs tilt within 15°, and the positioning error is less than 20 cm.
  • References | Supplementary Material | Related Articles

  • Code-Hopping Multiple Access and Its Pattern Design
  • CHEN Zijie, JI Xiaodong, PENG Mugen, WANG Zhifeng, LIU Xiqing
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 82-87. DOI:10.13190/j.jbupt.2021-056
  • Abstract ( 616 )     HTML( 304 )     　　
  • The hopping communication technology based on code divide multiple access, namely code-hopping multiple access, with pseudo-randomly constructed code-hopping pattern to detect multi-users, is regarded as an effective method to increase the user capacity. However, the significant access collision rate causes internal interference, seriously degrading the bit error performance and coding efficiency. To address the issue, a code hopping pattern with cyclic shifted address code scheme is proposed to reduce the access collision probability. The simulation results show that the proposed scheme can achieve better bit error performance than the hopping pattern based on the pseudo-random type.
  • References | Supplementary Material | Related Articles

  • Relay Transmission for Ambient Backscatter Communication Assisted CR-WPCNs
  • ZHUANG Yuandong, LI Xi, JI Hong, ZHANG Heli
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 88-93. DOI:10.13190/j.jbupt.2021-141
  • Abstract ( 1430 )     HTML( 247 )     　　
  • In order to improve the performance of overlay cognitive radio-wireless powered communication networks(CR-WPCNs), ambient backscatter communication technology is introduced to improve the throughput of secondary system. In CR-WPCNs based on ambient backscatter communication, considering the limited transmission distance of secondary transmitters, a relay transmission scheme based on non-orthogonal multiple access and energy harvesting is proposed, which improves the communication range and the throughput of secondary system. When the channel is busy, secondary transmitters will perform the ambient backscatter communication as well as the energy harvesting, and relays will perform the energy harvesting. The time resource allocation of this period needs to be taken into account. When the channel is idle, both secondary transmitters and relays will utilize the harvested energy to perform the active radio transmission, respectively. The time resource allocation of this period also needs to be taken into account. Based on these resource allocation problems, a throughput maximization problem for secondary system is formulated, and the Lagrange multiplier iterative algorithm is utilized to solve this problem. Simulation results demonstrate that the proposed scheme can significantly improve the throughput of secondary system.
  • References | Supplementary Material | Related Articles

  REPORTS

  • Trajectory Tracking for Wheeled Mobile Robots Considering the Castor Wheel's Torsion Angle Disturbance
  • TIAN Zhiyu, LIU Xiaoping, WANG Gang, ZHAO Yunlong, LI Xinghua
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 94-101. DOI:10.13190/j.jbupt.2021-108
  • Abstract ( 706 )     HTML( 513 )     　　
  • To study the influence of the disturbance of castor wheel's torsion on the trajectory tracking of wheeled mobile robots, a trajectory tracking control method considering the friction disturbance of the castor at the front of the robot and the noncoincidence between the centroid and the geometric center of the robot is proposed. First, the dynamic model of the wheeled mobile robot with castor wheel's disturbance is established. Then, according to the pose error model, the virtual velocity controller is designed by backstepping method to make the pose error converge. Next, combined with the disturbance observer, the friction disturbance caused by the torsion of the castor wheel during the robot's moving process is estimated. A torque controller based on the integral sliding mode idea is constructed to ensure the speed tracking. Finally, the stability and asymptotic convergence of the system are proved using the Lyapunov stability theory. Simulation and experimental results show that the load of the controller can be reduced when the disturbance caused by the castor wheel friction is fed back into the dynamic control controller. Compared with the control method which ignores the disturbance of the castor wheel, the root-mean-square of the maximum position error of the wheeled mobile robot is reduced by 37.37%, and the stability of the motion system can be improved.
  • References | Supplementary Material | Related Articles

  • A New Fast Convex Combination Affine Projection Sign Algorithm for S-type Functions
  • HUO Yuanlian, LIAN Peijun, QI Yongfeng, WANG Danfeng
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 102-107. DOI:10.13190/j.jbupt.2021-118
  • Abstract ( 699 )     HTML( 344 )     　　
  • Aiming at the problems of slow convergence speed and heavy computation of traditional convex combinatorial affine projection sign algorithm, a fast convex combinatorial affine projection sign algorithm based on S-type function is proposed. The algorithm uses a new S-type function to replace the sigmoidfunction in the traditional algorithm. It also, improves the iterative formula of joint parameters, avoids complex exponential operation and reduces the amount of calculation. Meanwhile, the instantaneous transfer scheme is adopted to make the convex combination algorithm accelerate the adaptation process of the small-step slow algorithm after the initial adaptation process or a sudden change, so as to improve the speed of the convex combination algorithm. Simulation results in the system identification and acoustic echo cancellation environment show that the algorithm has good mean square performance and tracking performance, and has faster convergence speed and lower computational complexity compared with the traditional convex combination affine projection sign algorithm.
  • References | Supplementary Material | Related Articles

  • Character Detection Method for PCB Image Based on Deep Learning
  • ZHANG Binyu, ZHAO Yanyun, DU Yunhao, WAN Junfeng, TONG Zhihang
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 108-114. DOI:10.13190/j.jbupt.2021-109
  • Abstract ( 920 )     HTML( 350 )     　　
  • Retrieve the printed circuit board (PCB) image with characters is an effective method for PCB fragments tracing. To this end, a high-performance character detection method for PCB images is proposed, which adopts feature pyramid network based on residual network and has two detecting heads to predict character distribution heatmaps. The local pattern consistency loss function is introduced to optimize the network model. A heatmap generation algorithm of character region for network training is presented. A series of strategies are adopted, such as data augmentation and multi-scale detection, which increases the performance of character detection. The test results on PCB image set show that the character detection accuracy is 95.6% and the recall rate is 92.4%. Especially, F1 score can reach 93.6%, which exceeds the comparison methods, proving that the proposed comprehensive detection method outperforms the state of the art methods of character detection in natural scene images.
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  • Physical Layer Security for CR-NOMA System in Vehicle-to-Everything
  • LI Meiling, YANG Xiaoxia, CHENG Wenjie, LU Zhaoming
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 115-120. DOI:10.13190/j.jbupt.2021-085
  • Abstract ( 879 )     HTML( 525 )     　　
  • Cognitive radio non-orthogonal multiple access (CR-NOMA) can meet large-scale connection requirements of the fifth generation of mobile communications system, and satisfy the demands of low latency, low power consumption and wide coverage of vehicle-to-everything communications. The physical layer security of the primary user of cooperative CR-NOMA network based on vehicle-to-everything is analyzed by deriving the secrecy outage probability. The influences of the transmission signal-to-noise ratio of secondary user, the number of secondary users, the target rate and the power allocation coefficient on the secrecy outage probability of primary user are studied. Both analysis and simulation results show that, in the presence of eavesdropper, the secrecy outage probability of the primary user of the considered network can be reduced by increasing the transmission signal-to-noise ratio of secondary user, appropriately selecting the number of secondary users and setting a proper target rate to improve the physical layer security.
  • References | Supplementary Material | Related Articles

  • Analysis on Underwater Transmission Characteristics of Polarized Photons
  • LIU Tao, QIU Jia, LI Jiajia, LIU Shuyu, WANG Sijia
  • Journal of Beijing University of Posts and Telecommunications. 2022, 45(1): 121-126. DOI:10.13190/j.jbupt.2021-126
  • Abstract ( 966 )     HTML( 387 )     　　
  • The Monte Carlo method is used to study the underwater transmission characteristics of polarized photons in four sea areas with different surface chlorophyll concentrations. First, a vertical transmission model of underwater quantum is established. Based on the model, the variations of chlorophyll concentration, absorption coefficient and scattering coefficient of light signal with seawater depth in the four sea areas are studied. In addition, analysis of the variation of polarization photon's scattering, attenuation and polarization characteristics with the transmission distance in four sea areas is carried out. The expression of calculating the number of received photons at different transmission distances is derived. The simulation results show that the absorption and scattering of optical signals in seawater channel are mainly affected by chlorophyll. With the increase of chlorophyll concentration in the surface layer of different sea areas, the scattering numbers of photons increase, whereas the farthest receiving distance decreases. The degree of polarization is also slightly reduced but basically remains unchanged. The research can shed some light on the performance analysis and the establishment of the satellite-submersible quantum communication system.
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