Digital Communications and Networks最新文献

{"title":"Application of maximum rank distance codes in designing of STBC-OFDM system for next-generation wireless communications","authors":"","doi":"10.1016/j.dcan.2022.12.022","DOIUrl":"10.1016/j.dcan.2022.12.022","url":null,"abstract":"<div><p>Space-Time Block Coded (STBC) Orthogonal Frequency Division Multiplexing (OFDM) satisfies higher data-rate requirements while maintaining signal quality in a multipath fading channel. However, conventional STBCs, including Orthogonal STBCs (OSTBCs), Non-Orthogonal (NOSTBCs), and Quasi-Orthogonal STBCs (QOSTBCs), do not provide both maximal diversity order and unity code rate simultaneously for more than two transmit antennas. This paper targets this problem and applies Maximum Rank Distance (MRD) codes in designing STBC-OFDM systems. By following the direct-matrix construction method, we can construct binary extended finite field MRD-STBCs for any number of transmitting antennas. Work uses MRD-STBCs built over Phase-Shift Keying (PSK) modulation to develop an MRD-based STBC-OFDM system. The MRD-based STBC-OFDM system sacrifices minor error performance compared to traditional OSTBC-OFDM but shows improved results against NOSTBC and QOSTBC-OFDM. It also provides 25% higher data-rates than OSTBC-OFDM in configurations that use more than two transmit antennas. The tradeoffs are minor increases in computational complexity and processing delays.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000032/pdfft?md5=76375afe89407451b3b95b680dc48309&pid=1-s2.0-S2352864823000032-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49508079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"UAV-supported intelligent truth discovery to achieve low-cost communications in mobile crowd sensing","authors":"","doi":"10.1016/j.dcan.2023.02.001","DOIUrl":"10.1016/j.dcan.2023.02.001","url":null,"abstract":"<div><p>Unmanned and aerial systems as interactors among different system components for communications, have opened up great opportunities for truth data discovery in Mobile Crowd Sensing (MCS) which has not been properly solved in the literature. In this paper, an Unmanned Aerial Vehicles-supported Intelligent Truth Discovery (UAV-ITD) scheme is proposed to obtain truth data at low-cost communications for MCS. The main innovations of the UAV-ITD scheme are as follows: (1) UAV-ITD scheme takes the first step in employing UAV joint Deep Matrix Factorization (DMF) to discover truth data based on the trust mechanism for an Information Elicitation Without Verification (IEWV) problem in MCS. (2) This paper introduces a truth data discovery scheme for the first time that only needs to collect a part of <em>n</em> data samples to infer the data of the entire network with high accuracy, which saves more communication costs than most previous data collection schemes, where they collect <em>n</em> or <em>kn</em> data samples. Finally, we conducted extensive experiments to evaluate the UAV-ITD scheme. The results show that compared with previous schemes, our scheme can reduce estimated truth error by 52.25%–96.09%, increase the accuracy of workers’ trust evaluation by 0.68–61.82 times, and save recruitment costs by 24.08%–54.15% in truth data discovery.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000366/pdfft?md5=69ea71653b14725a99a7749a25aa4e7f&pid=1-s2.0-S2352864823000366-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54171209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DTAIS: Distributed trusted active identity resolution systems for the Industrial Internet","authors":"","doi":"10.1016/j.dcan.2023.06.006","DOIUrl":"10.1016/j.dcan.2023.06.006","url":null,"abstract":"<div><p>In recent years, the Industrial Internet and Industry 4.0 came into being. With the development of modern industrial intelligent manufacturing technology, digital twins, Web3 and many other digital entity applications are also proposed. These applications apply architectures such as distributed learning, resource sharing, and arithmetic trading, which make high demands on identity authentication, asset authentication, resource addressing, and service location. Therefore, an efficient, secure, and trustworthy Industrial Internet identity resolution system is needed. However, most of the traditional identity resolution systems follow DNS architecture or tree structure, which has the risk of a single point of failure and DDoS attack. And they cannot guarantee the security and privacy of digital identity, personal assets, and device information. So we consider a decentralized approach for identity management, identity authentication, and asset verification. In this paper, we propose a distributed trusted active identity resolution system based on the inter-planetary file system (IPFS) and non-fungible token (NFT), which can provide distributed identity resolution services. And we have designed the system architecture, identity service process, load balancing strategy and smart contract service. In addition, we use Jmeter to verify the performance of the system, and the results show that the system has good high concurrent performance and robustness.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823001128/pdfft?md5=cf23cad644f75b7df56fb75cb45ada92&pid=1-s2.0-S2352864823001128-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45463107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors affecting forensic electric network frequency matching – A comprehensive study","authors":"","doi":"10.1016/j.dcan.2023.01.009","DOIUrl":"10.1016/j.dcan.2023.01.009","url":null,"abstract":"<div><p>The power system frequency fluctuations could be captured by digital recordings and extracted to compare with a reference database for forensic timestamp verification. It is known as the Electric Network Frequency (ENF) criterion, enabled by the properties of random fluctuations and intra-grid consistency. In essence, this is a task of matching a short random sequence within a long reference, whose accuracy is mainly concerned with whether this match could be uniquely correct. In this paper, we comprehensively analyze the factors affecting the reliability of ENF matching, including the length of test recording, length of reference, temporal resolution, and Signal-to-Noise Ratio (SNR). For synthetic analysis, we incorporate the first-order AutoRegressive (AR) ENF model and propose an efficient Time-Frequency Domain noisy ENF synthesis method. Then, the reliability analysis schemes for both synthetic and real-world data are respectively proposed. Through a comprehensive study, we quantitatively reveal that while the SNR is an important external factor to determine whether timestamp verification is viable, the length of test recording is the most important inherent factor, followed by the length of reference. However, the temporal resolution has little impact on performance. Finally, a practical workflow of the ENF-based audio timestamp verification system is proposed, incorporating the discovered results.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000226/pdfft?md5=314dd4ba91453ef2dd296636263ef8ca&pid=1-s2.0-S2352864823000226-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48805775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy-optimal DNN model placement in UAV-enabled edge computing networks","authors":"","doi":"10.1016/j.dcan.2023.02.003","DOIUrl":"10.1016/j.dcan.2023.02.003","url":null,"abstract":"<div><p>Unmanned aerial vehicle (UAV)-enabled edge computing is emerging as a potential enabler for Artificial Intelligence of Things (AIoT) in the forthcoming sixth-generation (6G) communication networks. With the use of flexible UAVs, massive sensing data is gathered and processed promptly without considering geographical locations. Deep neural networks (DNNs) are becoming a driving force to extract valuable information from sensing data. However, the lightweight servers installed on UAVs are not able to meet the extremely high requirements of inference tasks due to the limited battery capacities of UAVs. In this work, we investigate a DNN model placement problem for AIoT applications, where the trained DNN models are selected and placed on UAVs to execute inference tasks locally. It is impractical to obtain future DNN model request profiles and system operation states in UAV-enabled edge computing. The Lyapunov optimization technique is leveraged for the proposed DNN model placement problem. Based on the observed system overview, an advanced online placement (AOP) algorithm is developed to solve the transformed problem in each time slot, which can reduce DNN model transmission delay and disk I/O energy cost simultaneously while keeping the input data queues stable. Finally, extensive simulations are provided to depict the effectiveness of the AOP algorithm. The numerical results demonstrate that the AOP algorithm can reduce 18.14% of the model placement cost and 29.89% of the input data queue backlog on average by comparing it with benchmark algorithms.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S235286482300038X/pdfft?md5=da8e76fc1fd053a89c7fc37edbdb2f47&pid=1-s2.0-S235286482300038X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45698087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OAM mode purity improvement based on antenna array","authors":"","doi":"10.1016/j.dcan.2023.01.015","DOIUrl":"10.1016/j.dcan.2023.01.015","url":null,"abstract":"<div><p>Orbital Angular Momentum (OAM) waves are characterized by helical wave fronts and orthogonality between different modes. Therefore, OAM waves have huge potential in improving wireless communications' channel capacity and radar imaging's resolution. Consequently, the generation and application of OAM waves have attracted a lot of attention. And many methods are proposed to generate OAM waves. Although antenna array is the most popular method of generating OAM waves, OAM waves generated by antenna array have redundant modes. However, all advantages of OAM waves are closely related to infinite OAM modes. Thus, to better apply OAM waves to wireless communications and radar, it is very important to reduce unnecessary OAM modes and improve the OAM mode purity. In order to improve the OAM mode purity, two combined antenna arrays composed of X direction antenna and Y direction antenna array are proposed in this paper. The X direction antenna array and the Y direction antenna array are supplied by the excitations with the same amplitude and fixed phase shift. The overall phase shift of the X direction antenna array is <em>π</em>/2 more or less than that of the Y direction antenna array. The results of formulas and antenna models in CST show that the combined antenna arrays can generate OAM waves with less redundant modes in <strong><em>x</em></strong> component, <strong><em>y</em></strong> component and <strong><em>z</em></strong> component. Besides, the <strong><em>z</em></strong> component carries pure OAM modes.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000287/pdfft?md5=98ae7f3b30d45a60b9b9d429ff0da54f&pid=1-s2.0-S2352864823000287-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44561906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new adaptive co-site broadband interference cancellation method with auxiliary channel","authors":"","doi":"10.1016/j.dcan.2022.10.025","DOIUrl":"10.1016/j.dcan.2022.10.025","url":null,"abstract":"<div><p>With the boom of the communication systems on some independent platforms (such as satellites, space stations, airplanes, and vessels), co-site interference is becoming prominent. The adaptive interference cancellation method has been adopted to solve the co-site interference problem. But the broadband interference cancellation performance of traditional Adaptive Co-site Interference Cancellation System (ACICS) with large delay mismatching and antenna sway is relatively poor. This study put forward an Adaptive Co-site Broadband Interference Cancellation System With Two Auxiliary Channels (ACBICS-2A). The system model was established, and the steady state weights and Interference Cancellation Ratio (<em>ICR</em>) were deduced by solving a time-varying differential equation. The relationship of <em>ICR</em>, system gain, modulation factor, interference signal bandwidth and delay mismatching degree was acquired through an in-depth analysis. Compared with traditional adaptive interference cancellation system, the proposed ACBICS-2A can improve broadband interference cancellation ability remarkably with large delay mismatching and antenna sway for the effect of auxiliary channel. The maximum improved <em>ICR</em> is more than 25 ​dB. Finally, the theoretical and simulation results were verified by experiments.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864822002346/pdfft?md5=eebd8f71c3b2cad507364f810e2335ae&pid=1-s2.0-S2352864822002346-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47289783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vehicle-oriented ridesharing package delivery in blockchain system","authors":"","doi":"10.1016/j.dcan.2022.12.008","DOIUrl":"10.1016/j.dcan.2022.12.008","url":null,"abstract":"<div><p>Package delivery via ridesharing provides appealing benefits of lower delivery cost and efficient vehicle usage. Most existing ridesharing systems operate the matching of ridesharing in a centralized manner, which may result in the single point of failure once the controller breaks down or is under attack. To tackle such problems, our goal in this paper is to develop a blockchain-based package delivery ridesharing system, where decentralization is adopted to remove intermediaries and direct transactions between the providers and the requestors are allowed. To complete the matching process under decentralized structure, an Event-Triggered Distributed Deep Reinforcement Learning (ETDDRL) algorithm is proposed to generate/update the real-time ridesharing orders for the new coming ridesharing requests from a local view. Simulation results reveal the vast potential of the ETDDRL matching algorithm under the blockchain framework for the promotion of the ridesharing profits. Finally, we develop an application for Android-based terminals to verify the ETDDRL matching algorithm.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864822002760/pdfft?md5=383be21d03496ac173d637bd5904abcb&pid=1-s2.0-S2352864822002760-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46417608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"XMAM:X-raying models with a matrix to reveal backdoor attacks for federated learning","authors":"Jianyi Zhang ,&nbsp;Fangjiao Zhang ,&nbsp;Qichao Jin ,&nbsp;Zhiqiang Wang ,&nbsp;Xiaodong Lin ,&nbsp;Xiali Hei","doi":"10.1016/j.dcan.2023.01.017","DOIUrl":"10.1016/j.dcan.2023.01.017","url":null,"abstract":"<div><p>Federated Learning (FL), a burgeoning technology, has received increasing attention due to its privacy protection capability. However, the base algorithm FedAvg is vulnerable when it suffers from so-called backdoor attacks. Former researchers proposed several robust aggregation methods. Unfortunately, due to the hidden characteristic of backdoor attacks, many of these aggregation methods are unable to defend against backdoor attacks. What's more, the attackers recently have proposed some hiding methods that further improve backdoor attacks' stealthiness, making all the existing robust aggregation methods fail.</p><p>To tackle the threat of backdoor attacks, we propose a new aggregation method, X-raying Models with A Matrix (XMAM), to reveal the malicious local model updates submitted by the backdoor attackers. Since we observe that the output of the <em>Softmax</em> layer exhibits distinguishable patterns between malicious and benign updates, unlike the existing aggregation algorithms, we focus on the <em>Softmax</em> layer's output in which the backdoor attackers are difficult to hide their malicious behavior. Specifically, like medical X-ray examinations, we investigate the collected local model updates by using a matrix as an input to get their <em>Softmax</em> layer's outputs. Then, we preclude updates whose outputs are abnormal by clustering. Without any training dataset in the server, the extensive evaluations show that our XMAM can effectively distinguish malicious local model updates from benign ones. For instance, when other methods fail to defend against the backdoor attacks at no more than 20% malicious clients, our method can tolerate 45% malicious clients in the black-box mode and about 30% in Projected Gradient Descent (PGD) mode. Besides, under adaptive attacks, the results demonstrate that XMAM can still complete the global model training task even when there are 40% malicious clients. Finally, we analyze our method's screening complexity and compare the real screening time with other methods. The results show that XMAM is about 10–10000 times faster than the existing methods.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000305/pdfft?md5=0dddf5e58bbb78a91191743e84018831&pid=1-s2.0-S2352864823000305-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversified and compatible web APIs recommendation based on game theory in IoT","authors":"","doi":"10.1016/j.dcan.2023.02.002","DOIUrl":"10.1016/j.dcan.2023.02.002","url":null,"abstract":"<div><p>With the ever-increasing popularity of Internet of Things (IoT), massive enterprises are attempting to encapsulate their developed outcomes into various lightweight Web Application Programming Interfaces (APIs) that can be accessible remotely. In this context, finding and writing a list of existing Web APIs that can collectively meet the functional needs of software developers has become a promising approach to economically and easily develop successful mobile applications. However, the number and diversity of candidate IoT Web APIs places an additional burden on application developers’ Web API selection decisions, as it is often a challenging task to simultaneously ensure the diversity and compatibility of the final set of Web APIs selected. Considering this challenge and latest successful applications of game theory in IoT, a Diversified and Compatible Web APIs Recommendation approach, namely <em>DivCAR</em>, is put forward in this paper. First of all, to achieve API diversity, <em>DivCAR</em> employs random walk sampling technique on a pre-built “API-API” correlation graph to generate diverse “API-API” correlation subgraphs. Afterwards, with the diverse “API-API” correlation subgraphs, the compatible Web APIs recommendation problem is modeled as a minimum group Steiner tree search problem. A sorted set of multiple compatible and diverse Web APIs are returned to the application developer by solving the minimum group Steiner tree search problem. At last, a set of experiments are designed and implemented on a real dataset crawled from <span><span><em>www.programmableweb.com</em></span><svg><path></path></svg></span>. Experimental results validate the effectiveness and efficiency of our proposed <em>DivCAR</em> approach in balancing the Web APIs recommendation diversity and compatibility.</p></div>","PeriodicalId":48631,"journal":{"name":"Digital Communications and Networks","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352864823000378/pdfft?md5=34b1df780202aad9ea6473139117386e&pid=1-s2.0-S2352864823000378-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47720766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}