Large-scale Communication Systems Research Articles

Pilot spoofing detection for large-scale MIMO communication systems

For large-scale MIMO systems, upon the investigation of pilot spoofing on system security capacity, a novel detection scheme is proposed and the contaminated channel state information (CSI) is corrected. Specifically, a two-parts pilot sequence is exploited to implement channel estimation. The first one is conventional, and the other is partially randomized on the top of the first one. Leveraging the difference between the statistical characteristic of the estimated CSIs in the two parts, a pilot spoofing detector is established based on the principle of the maximum likelihood ratio. Meanwhile, the contaminated CSI is purified with the obtained information in pilot spoofing detection, and thus system security capacity can be improved greatly. Finally, simulation results are presented to evaluate the superior performance of the proposed scheme.

Multi-modal mutation cooperatively coevolving algorithm for resource allocation of large-scale D2D communication system

With the rapid growth in cellular user quantity and quality of service demand, the resource allocation in device-to-device communication system significantly affects the overall efficiency and user experience. In this study, the resource allocation for large-scale device-to-device communication system is modelled as a constrained optimization problem with thousands of dimensionalities. Then, the variable-coupling relationship of the developed model is analysed and the mathematical proof is firstly provided, and a novel algorithm namely multi-modal mutation cooperatively coevolving particle swarm optimization is developed to optimize the ultra-high dimensional model. Finally, efficacy of the developed method is verified by a comprehensive set of case studies, some famous algorithms for the specialized literature are also employed for comparison. Experimental results shown that the developed algorithm can obtain accurate and robust optimization performance for different system scales. In addition, when the system scale increases to 1000 cellular users and 300 D2D-pair users, the developed method can still outperform the compared algorithms and output accurate resource allocation solution.

High-speed silicon-integrated photonic radio frequency switch based on optical switching.

Photonic radio frequency (RF) switches are promising to replace conventional electronic RF switches in modern RF communication systems owing to their high switching speed and immunity to electromagnetic interference. However, existing photonic RF switches are generally based on frequency or polarization filtering. Thus, they require more light sources and filters to increase the number of switching channels, consequently limiting scalability. We propose a silicon-integrated photonic RF switch based on optical switching. RF signals are first modulated into the optical domain and switched through phase control of the phase shifters in the optical switch. Switching is not related to the frequency or polarization of the optical carriers, thus reducing the number of light sources required. Experimental results demonstrate 10-GHz switching of two RF signals with frequencies of 20 GHz and 30 GHz. The proposed photonic RF switch can be further expanded to form a large switch matrix, possibly contributing to the development of large-scale RF communication systems.

Blockchain-Based Security Configuration Management for ICT Systems

The world has become increasingly dependent on large-scale and distributed information and communication technology (ICT) infrastructures and systems in sectors such as energy, transport, banking, healthcare, water supply, and digital services, while their protection is considered of paramount importance and has already drawn remarkable attention from governments and key industry players. Establishing common approaches by leveraging existing frameworks and cyber security practices for improving the security postures of those systems is one of the major objectives for ensuring an adequate level of protection and avoiding the detrimental effects of disruptions on society and citizens. Configuration management (CM) is one of those common practices for establishing and maintaining the integrity and consistency of a system and its elements with regard to the function, performance, and status of technical and physical attributes, and it contributes to a desirable security posture throughout the lifecycle of a system. This study addresses the importance of CM, and while considering the corresponding frameworks, standards, and best practices, it proposes a permissioned blockchain-based approach, that inherits the benefits of the blockchain technology and ensures the integrity of the systems’ configuration across the complete lifecycle management of its products and services as an underlying model for mapping and integrating CM functions. Furthermore, this study briefly presents the benefits and challenges of the application of permissioned blockchain models and proposes a smart-contract-based role-based access control mechanism, in addition to presenting an operating concept based on brief but real-life lifecycle requirements of organizational configuration management.

Strategy of full-C-band fast wavelength switching and aging mitigation at tunable DFB laser array with current/temperature cooperative control

We proposed a current/temperature cooperative control to solve the problem of laser aging in the conventional fast wavelength switching method when injecting a larger current at the tunable distributed feedback (DFB) laser array (TLA). Previously, we demonstrated a 400 GHz wide uni-directional switching at a single DFB laser in the TLA with the cooperative control, which switched fastly and retarded laser aging. For large-scale optical communication systems, we have improved the cooperative control method and expanded its application scenarios. In this paper, we not only proposed and achieved bi-directional wavelength switching with cooperative control at a single DFB laser but also realized bi-directional wavelength switching with cooperative control covering full-C-band at two DFB lasers of the TLA. We demonstrated that the switching time is less than 200 ms and estimated that the TLA’s lifetime is improved by more than 40 times.

Birth-and-Death-Based Multipath Cluster Channel Model for Massive MIMO

In this paper the propagation characteristics of large-scale multi-antenna communication system are investigated. we give an insight into sub-channel correlation, and from which the non-stationary characteristics are deduced. Some in-field channel sounding are carried out with interesting frequencies of 1.4725GHz and 4.5GHz. Regarding to the channel measurements and data analysis we take an educated guess, and construct a birth-and-death-based Markov Model to characterize the multipath cluster’s evolution over the array, which explained the micro-changes of the radiation propagation environment. And the model is found to be highly coincide with propagation theory.

Quantum error correction architecture for qudit stabilizer codes

Quantum communication channels benefit from nonbinary entanglement-assisted stabilizer codes using preshared entangled states for achieving better error correction capability compared to those that do not use preshared entanglement, making them indispensable for realizing large-scale quantum computing and communication systems over qudits. We provide a previously unreported design architecture of the syndrome computation unit for qudit stabilizer codes based on classical additive codes using discrete Fourier transform gates, $\mathrm{ADD}$ gates, and multiplication gates. The proposed syndrome computation circuit architectures are necessary toward the implementable realization of such entanglement-assisted and -unassisted qudit stabilizer codes within the quantum transceiver system. We further provide an equivalent design architecture of the syndrome computation unit that decomposes into two syndrome computation units based on X errors and Z errors separately for entanglement-assisted and -unassisted qudit CSS codes. The proposed quantum error correction architectures are useful for building high-density coded quantum memories for archival quantum storage.

Joint Detection and Decoding of Mixed-ADC Large-Scale MIMO Communication Systems With Protograph LDPC Codes

Nowadays, large-scale multiple-input multiple-output (LS-MIMO) with low-resolution analog-to-digital converters (ADCs) is a favorable transmission scheme for 5G and beyond wireless networks to reduce the power consumption of the radio frequency chains and to increase the network capacity. This paper derives the joint message-passing detection and decoding algorithm based on the double-layer graph for LS-MIMO communication systems with mixed-ADCs. The new protograph extrinsic information chart (PEXIT) algorithm is developed to analytically evaluate the performance of protograph low-density parity-check code under various mixed-ADC combinations and LS-MIMO configuration scenarios. The simulation results validate the accuracy of the proposed algorithm. Furthermore, our experiments show that the mixed-ADC system can achieve a significant power gain even when only one received antenna is equipped with high-resolution ADCs. It is observed that 4-bit or 5-bit resolution is an optimal choice for the high-resolution receive antennas. Interestingly, mixed-ADC systems with Ternay-ADCs generally provide significant gains at the cost of the increase in the average resolution by a fraction of a bit. There are specific scenarios where the Ternary-ADC-based system outperforms the 1-bit-ADC based system at the same or lower average resolution. In the particular case of 16 ×16 MIMO configuration where the number of low-resolution antennas is N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> = 12 and the number of high-resolution antennas is N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> = 4, the Ternary-ADC based system can obtain a power gain of about 2 dB at the frame error rate (FER) or bit error rate (BER) level of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> .

Two-Round Password-Based Authenticated Key Exchange from Lattices

Password-based authenticated key exchange (PAKE) allows participants sharing low-entropy passwords to agree on cryptographically strong session keys over insecure networks. In this paper, we present two PAKE protocols from lattices in the two-party and three-party settings, respectively, which can resist quantum attacks and achieve mutual authentication. The protocols in this paper achieve two rounds of communication by carefully utilizing the splittable properties of the underlying primitive, a CCA (Chosen-Ciphertext Attack)-secure public key encryption (PKE) scheme with associated nonadaptive approximate smooth projection hash (NA-ASPH) system. Compared with other related protocols, the proposed two-round PAKE protocols have relatively less communication and computation overhead. In particular, the two-round 3PAKE is more practical in large-scale communication systems.

Resource and Network Management Framework for a Large-Scale Satellite Communications System

Resource and Network Management Framework for a Large-Scale Satellite Communications System

Expectations of artificial intelligence and the performativity of ethics: Implications for communication governance

This article draws on the sociology of expectations to examine the construction of expectations of ‘ethical AI’ and considers the implications of these expectations for communication governance. We first analyse a range of public documents to identify the key actors, mechanisms and issues which structure societal expectations around artificial intelligence (AI) and an emerging discourse on ethics. We then explore expectations of AI and ethics through a survey of members of the public. Finally, we discuss the implications of our findings for the role of AI in communication governance. We find that, despite societal expectations that we can design ethical AI, and public expectations that developers and governments should share responsibility for the outcomes of AI use, there is a significant divergence between these expectations and the ways in which AI technologies are currently used and governed in large scale communication systems. We conclude that discourses of ‘ethical AI’ are generically performative, but to become more effective we need to acknowledge the limitations of contemporary AI and the requirement for extensive human labour to meet the challenges of communication governance. An effective ethics of AI requires domain appropriate AI tools, updated professional practices, dignified places of work and robust regulatory and accountability frameworks.

Resource and Network Management for Satellite Communications Systems: A Chance-Constrained Approach

In this paper, we propose an optimization framework for the resource and network management in large-scale satellite communications (SATCOM) systems with stochastic and time-varying communication requests. Because further expansions of SATCOM systems are expected in the near future, it is of practical importance to develop management methodologies for efficiently and robustly operating large-scale SATCOM systems. To address this problem, in this paper, we formulate a SATCOM network optimization problem within the framework of the chance-constrained model predictive control. In this problem, we require that a joint chance constraint on the bandwidth loss rate is satisfied with a user-specified performance and probability. Because the joint chance constraint is nonlinear in design variables, we relax the constraint to a linear deterministic one for reformulating the original problem into a relaxed deterministic problem. We numerically verify that the proposed method outperforms a baseline methodology and therefore allows us to efficiently manage large-scale SATCOM systems.

Пропаганда на тимчасово окупованих територіях Донецької та Луганської областей: інституціональний та організаційний вимір

The Russian propaganda war against Ukraine is an example of information warfare, which is a reflection of a wide range of non-military instruments that are used to exert pressure and influence over the behavior of the countries. With a skillful combination of disinformation, malicious attacks on large-scale information and communication systems, combined with psychological pressure, it is more dangerous than traditional weapons systems The article deals with the psychological aspect of information warfare, the leading component is the propaganda. Smartened and supplemented with new technologies, it is actively and masterly used by the Russian Federation to manipulate the mass consciousness of the international community, its own population, citizens of Ukraine, the occupied population of the occupied territories. The ideological fundamental theses of Russian propaganda are the "Donbass mythologeme" with the thesis about "civil conflict"; the project of "Novorossiya", which denies the historical belonging of Donbass to Ukraine and the separateness of Donbass, together to justify the "fight against Ukrainian fascism" for the independence of the region and its further integration into Russia. Propaganda tools are a mixture of militarized Russian and Soviet content and symbols in the public sphere, education, youth upbringing, leisure activities, and the like. The brainwashing of the population is based on a centralized information space management system. The main role in its construction is played by the Russian Federation in order to legitimize the occupation policy of the Russian authorities, to create the illusion of independence of decisions and actions of the occupation administration; an extensive media system. The goal of the mental alienation of the population of the temporarily occupied territories from Ukraine is achieved in various ways: the militarization of consciousness, the education of the Soviet Donbas identity, the imposition of historical myths, the creation of a quasi-held attributive simulacrum, and the like. Total control over information resources and communication means provides unlimited opportunities for the occupation administration to carry out propaganda actions, and the length of time makes the task of counter-propaganda extremely difficult.

Spatially Distributed Molecular Communications: An Asynchronous Stochastic Model

This letter studies large-scale molecular communication systems by using point processes theory. A swarm of point transmitters randomly placed in a bounded space are considered in conjunction with a single fully absorbing receiver. The transmitters’ positions are modeled by a spatial point process, but the global clock assumption, adopted by prior works, is here removed. More precisely, the emission times for each point transmitter are considered as random and are modeled by a non-stationary time-domain point process. We show that, if the intensity function is the same for all time point processes (thus taking the meaning of a distributed input), the average number of received molecules per time unit (receiving rate) can be computed through a convolution: the collective response to a one-molecule emission can be properly interpreted as the impulse response. This models unifies all the widely known transmitter models (exact concentration, Poisson concentration, and timing transmitter), which result as special cases. Analytical expressions for the receiving rate are provided and validated by Monte-Carlo simulations.

Multichannel Power Allocation for Maximizing Energy Efficiency in Wireless Networks

This paper aims at solving two classes of energy efficiency (EE) maximization problems in multiple channels wireless communication systems. First, the EE maximization problem with sum power constraint is solved based on the geometric water-filling approach; and second, the approach is extended into the EE maximization problem with additional least throughput requirement constraint. Our proposed algorithms make use of the water-filling structure of the optimal solution and provide exact and computation efficient solution to the energy-efficient power allocation problems. The proposed algorithms also have excellent scalability, which is applicable for large-scale wireless communication systems. Optimality of the proposed algorithms is strictly proved, and the proposed algorithms only require low-degree polynomial computational complexity. Numerical results are presented to demonstrate the efficiency of the proposed algorithms. To the best of our knowledge, no prior algorithms in the existing literature could provide such solutions to the EE maximization problems under the merit of exactness and the efficiency.

Analytical modelling and optimization analysis of large-scale communication systems and networks with repairmen policy

The large-scale communication systems and computer networks provide flexible, efficient, and highly available services to their users. However, the practical large-scale systems result in unpredictable, fault-tolerant, often detrimental outcomes. This leads to developing and designing analytical models to understand and predict of complex system behaviour in order to ensure availability of large-scale systems. In this paper, analytical modelling and optimization analysis are presented for large-scale systems. The key contribution of this paper is twofold. First, a generic approximate solution approach is adapted and developed for performability modelling which considers performance and availability issues of large number of nodes with multi-repairmen. The analytical model and solution presented here are capable of considering large number of nodes up to thousands and able to incorporate availability issues of the system. Second and foremost, the relationship between the number of nodes and the number of repairmen is presented with an optimization analysis for large-scale systems. In order to show the efficacy and the accuracy of the proposed approach, the results obtained from the analytical model is validated with the results obtained from the simulations.

SMLXL: Scaling the smart city, from metropolis to individual

The ‘smart city’ is an oft-cited techno-urban imaginary promoted by businesses and governments alike. It thinks big, and is chiefly imagined in terms of large-scale information communications systems that hinge on the collection of real-time and so-called ‘big data’. Less talked about are the human-scale implications and user-experience of the smart city. Much of the current academic scholarship on smart cities offers synoptic and technical perspectives, leaving the users of smart systems curiously unaccounted for. While they purport to empower citizens, smart cities initiatives are rarely focused at the citizen-scale, nor do they necessarily attend to the ways initiatives can be user-led or co-designed. Drawing on the outcomes of a university studio, this article rethinks the smart city as a series of urban scales—metropolis, community, individual, and personal—and proposes an analytical model for classifying smart city initiatives in terms of engagement. Informed by the theory of proxemics, the model proposed analyses smart city initiatives in terms of the scope of their features and audience size; the actors accountable for their deployment and maintenance; their spatial reach; and the ability of design solutions to re-shape and adapt to different urban scenarios and precincts. We argue that the significance of this model lies in its potential to facilitate modes of thinking across and between scales in ways that can gauge the levels of involvement in the design of digitally mediated urban environments, and productively re-situate citizens as central to the design of smart city initiatives.

Analyzing Large-Scale Multiuser Molecular Communication via 3-D Stochastic Geometry

Information delivery using chemical molecules is an integral part of biology at multiple distance scales and has attracted recent interest in bioengineering and communication theory. Potential applications include cooperative networks with a large number of simple devices that could be randomly located (e.g., due to mobility). This paper presents the first tractable analytical model for the collective signal strength due to randomly-placed transmitters in a three-dimensional (3D) large-scale molecular communication system, either with or without degradation in the propagation environment. Transmitter locations in an unbounded and homogeneous fluid are modelled as a homogeneous Poisson point process. By applying stochastic geometry, analytical expressions are derived for the expected number of molecules absorbed by a fully-absorbing receiver or observed by a passive receiver. The bit error probability is derived under ON/OFF keying and either a constant or adaptive decision threshold. Results reveal that the combined signal strength increases proportionately with the transmitter density, and the minimum bit error probability can be improved by introducing molecule degradation. Furthermore, the analysis of the system can be generalized to other receiver designs and other performance characteristics in large-scale molecular communication systems.

Adaptive antenna-activation based beamforming for large-scale MIMO communication systems of high speed railway

Large-scale array aided beamforming improves the spectral efficiency (SE) as a benefit of high angular resolution. When dual-beam downlink beamforming is applied to the train moving towards cell edge, the inter-beam ambiguity (IBA) increases as the directional difference between beams becomes smaller. An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA. In the district near the base station (BS), all antenna elements (AEs) were activated to generate two beams. As the distance from the train to the BS increased, only the minimum number of AEs satisfying the resolution criterion would be activated. At the cell edge, one beam was switched off due to intolerable IBA. The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival (DOA) estimation error.

Adaptive power control for mutual interference avoidance in industrial internet-of-things

With the vigorous development of the Internet of Things and 5G technology, such as machine-to-machine and device-todevice, all kinds of data transmission including environmental monitoring and equipment control strengthens the key role of wireless sensor networks in the large-scale wireless communication system. However, especially in the complex industrial wireless applications, the low utilization efficiency of the limited wireless radio resource enhances the coexistence problem between heterogeneous networks. In this paper, from the severe mutual interference point of view, a mathematical model regarding cumulative interferences in the industrial wireless sensor networks is described. Then, from the perspective of mutual interference avoidance, an adaptive power control scheme is proposed in order to handle the normal communication needs on both the primary link and the secondary link. At last, nonlinear programming is taken to solve the corresponding optimization problem. Some typical analyses are given to verify the effectiveness of the proposed scheme on optimizing the tradeoff between the system throughput and energy consumption. Especially, the energy-efficiency of the novel scheme for Industrial Internet of Things is also analysed. Results show that the proposed power control is efficient. The throughput could be enhanced and the energy consumption could be reduced with the guarantee of mutual interference avoidance.