With the rapid popularization of smartphones, various applications (Application: APP) have come into being. Therefore, automated testing of mobile applications is particularly important. At present, the automated test...
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This paper focuses on the resource allocation problem of multiplexing two different service scenarios, enhanced mobile broadband (eMBB) and ultrareliable low latency (URLLC) in 5G New Radio, based on dynamic numerolog...
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To mitigate the severe effect of pilot contamination, a novel graph coloring (NGC) based algorithm is applied to pilot assignment in cell-free massive multiple-input multiple-output (MIMO) systems. Specifically, first...
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ISBN:
(纸本)9781665409513
To mitigate the severe effect of pilot contamination, a novel graph coloring (NGC) based algorithm is applied to pilot assignment in cell-free massive multiple-input multiple-output (MIMO) systems. Specifically, firstly, the potential pilot contamination intensity among users is calculated by utilizing the large-scale fading between users and access points (APs). Then, the contamination threshold is set to perform the sparsification and an interference graph describing the user interference relationship is constructed. Finally, the proposed algorithm is used to implement pilot assignment in the interference graph. In addition, an iterative grid search (IGS) approach is adopted to update the threshold to ensure that the system downlink sum-rate is maximized. The numerical results reveal that the proposed NGC pilot assignment algorithm with optimized thresholds can remarkably improve the system performance compared with previous pilot assignment schemes.
Electronic modulation on the inert basal plane of transition-metal dichalcogenides(TMDs)through vacancy defect excitation,although extremely challenging,is urgent for understanding the factors that impact the hydrogen...
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Electronic modulation on the inert basal plane of transition-metal dichalcogenides(TMDs)through vacancy defect excitation,although extremely challenging,is urgent for understanding the factors that impact the hydrogen evolution reaction(HER)catalytic ***,ultrathin WS2 nanosheets with precise quantitative single atomic S-vacancy on the inert basal plane were flexible prepared through hydrogen peroxide etching *** as-synthesized single atomic S-vacancy defect WS2(SVD-WS2)nanoflake with the activated basal plane exhibited an impressive overpotential of 137 mV at a current density of 10 mA·cm^(-2) and a Tafel slope of 53.9 mV dec^(-1).Furthermore,anchoring on the defect graphene matrix,the assembled two-dimensional(2D)stacking heterojunction exhibits further enhanced HER catalytic activity(an overpotential of 108 mV vs.10 mA·cm^(-2) and a Tafel slope of 48.3 mV·dec^(-1))and stability(〜10%decline after 9,000 cycles),which attributed to the electronic structure modulation from the synergetic interactions between SVD-WS_(2) and defect *** finding provides a smart defects introduce strategy to trigger high-efficiency hydrogen evolution over WS_(2) nanosheets and a general 2D heterojunctions fabricated inspiration based on strong interaction interface.
Target tracking is currently a hot research topic in Computer Vision and has a wide range of use in many research fields. However, due to factors such as occlusion, fast motion, blur and scale variation, tracking meth...
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This paper presents a joint parallel loop filtering algorithm based on multi-thread load balancing in HEVC decoding, which implements the parallel processing of deblocking filtering (DBF) and sample adaptive compensat...
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In order to meet the demand for bigger data and lower time of processing data in future industry and daily life, the paper proposes a scheme combining multi-access edge computing (MEC) and mode division multiple acces...
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ISBN:
(纸本)9781665450867
In order to meet the demand for bigger data and lower time of processing data in future industry and daily life, the paper proposes a scheme combining multi-access edge computing (MEC) and mode division multiple access (MDMA). To greatly reduce the MEC system transmission and data processing time of a scenario where multiple devices offload the large amount of data onto the MEC server within the coverage area of base station, modes are used as new communication resources with frequency to form resources blocks which will be allocated. Because the model of MEC system using MDMA contains continuous and boolean variables and the exclusive constraints about using resources blocks, the paper proposes an algorithm combining modified differential evolution (DE), tournament selection (TS) and logical operation, which has a great performance.
With the advancement of 5G technology, user demand grows, resources become scarce and differentiated services place greater requirements on performance in slice-MEC system. However, optimizing works in the vast majori...
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ISBN:
(纸本)9781665450867
With the advancement of 5G technology, user demand grows, resources become scarce and differentiated services place greater requirements on performance in slice-MEC system. However, optimizing works in the vast majority of existing research focus only on slice selection, resource orchestration, utility improvement from the perspective of users, without considering whole system's power consumption cost. Firstly, to get over this dilemma, a two-tier architectural model for slice-MEC system is proposed, which is mainly divided into the slice instance layer and infrastructure layer. Next, we establish the optimization problem of minimizing weighted power consumption cost while guaranteeing requirements of delay and rate, taking into account both communication and computational resources. Moreover, to solve the problem above, the HPCA-based resource management and computing offloading algorithm is designed. Finally, simulation results show that the proposed algorithm in this paper outperforms than benchmark algorithms and we also analyse the performance of the system by varying different parameter conditions.
To enhance the security in the computational offloading process of Mobile Edge Computing (MEC) systems, this paper proposes a physical layer secure transmission scheme based on Intelligent Reflecting Surface (IRS) ass...
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ISBN:
(纸本)9781665450867
To enhance the security in the computational offloading process of Mobile Edge Computing (MEC) systems, this paper proposes a physical layer secure transmission scheme based on Intelligent Reflecting Surface (IRS) assistance. In this scheme, IRS is added to facilitate the task transfer between the user and the MEC server, while suppressing eavesdroppers from eavesdropping on user information, thus achieving a secure computing offload for the system. In order to maximize the safe transmission rate of the system, a flow-form optimization algorithm based on alternating optimization and conjugate gradient is designed to obtain the users transmit power as well as the phase shift of the IRS. Based on this, the computational offload rate of users and the computational resources of MEC servers are optimized by heuristic algorithms to minimize the computational offload delay of MEC systems while ensuring secure transmission. Simulation results show that the proposed scheme can reduce the total computational offload delay while guaranteeing secure transmission of the MEC system compared with other benchmark schemes and traditional artificial noise assisted schemes.
The paper mainly studies how to better apply non-orthogonal multiple access (NOMA) to mobile edge computing (MEC) system under the condition of considering offload interruption, and adopts user collaboration(UC) and w...
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ISBN:
(纸本)9781665450867
The paper mainly studies how to better apply non-orthogonal multiple access (NOMA) to mobile edge computing (MEC) system under the condition of considering offload interruption, and adopts user collaboration(UC) and wireless power transfer (WPT) technology. First, two users use WPT to collect energy from the base station equipped with the MEC server. Then, to better increase the system capacity and performance, the near user acts as a relay to help the far user offload some of the tasks to the MEC server, using the NOMA protocol for both users. To obtain an energy-efficient MEC design, we first derive the outage probability for both users, then the offloading time allocation and power allocation are jointly designed to maximize the effective computational efficiency, which is a non-convex problem. To deal with the problem, we first transform it into a relaxation problem and then solve it using the sequential convex approximation (SCA) method. Finally, numerical results demonstrate that the proposed scheme introduces NOMA and UC into MEC simultaneously, which has better advantages compared with other schemes.
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