Arumugam Nallanathan

Queen Mary, University of London | QMUL · School of Electronic Engineering and Computer Science

Low-latency computational tasks in Internet-of-Things (IoT) networks require short-packet communications. In this paper, we consider a mobile edge computing (MEC) network under time division multiple access (TDMA)-based short-packet communications. Within the considering network, a mobile user partitions an urgent task into multiple sub-tasks and d...

In this paper, we investigate the joint design of beamforming vectors and trajectory for unmanned aerial vehicles (UAVs) in integrated sensing and communications networks, aiming to maximize the achievable covert rate (ACR) for legitimate users against multiple passive wardens. Considering the worst-case scenario, where the wardens strategically se...

A DeepCAPA (Deep Learning for Continuous Aperture Array (CAPA)) framework is proposed to learn beamforming in CAPA systems. The beamforming optimization problem is firstly formulated, and it is mathematically proved that the optimal beamforming lies in the subspace spanned by users' conjugate channel responses. Two challenges are encountered when d...

Network slicing is a key technology in sixth-generation (6G) communication networks. However, the performance of virtualized nodes sharing cache resources in 6G network slicing is degraded by the inappropriate allocation of resources. This paper proposes a cache resource allocation strategy for 6G network slicing based on game dynamics (RASGD). A 6...

Existing works on space-air-ground integrated networks (SAGINs) have not sufficiently explored the synergy between control- and user-plane separation (CUPS) and end-to-end (E2E) network slicing. In this paper, we present a new paradigm of E2E network slicing for CUPS-based SAGIN (CUPS-SAGIN), where the control base stations (BSs), control unmanned...

Unmanned aerial vehicle (UAV)-enabled mobile edge computing (MEC) can provide flexible computing service for terminal-devices (TDs). However, malicious active aerial eavesdroppers can perform air-to-ground eavesdropping and air-to-air attacking, which makes TDs’ tasks offloading computation more vulnerable, posing significantly secure threats to UA...

A hybrid near- and far- field cascaded channel prediction scheme is proposed for reconfigurable intelligent surface (RIS) assisted low earth orbit (LEO) satellite networks. In particular, an efficient neural network architecture, inspired by the intrinsic characteristics of wireless signals and termed the signal-informed network (SIN), is exploited...

This paper proposes a novel integrated sensing and communication (ISAC) receiver design framework for OTFS (orthogonal time frequency space)-based MIMO (multi-inputmulti-output) systems from a unified perspective of variational inference. We first construct a factor graph representation for the OTFS-based MIMO system according to the factorization...

In the evolving landscape of wireless communications, extremely large-scale multiple-input multiple-output (XL-MIMO) systems offer promising enhancements in capacity and spectral efficiency, particularly in near-field scenarios. This paper investigates polar-domain channel estimation methods for near-field wideband XL-MIMO systems, proposing a nove...

This article targets at unlocking the potentials of a class of prominent generative artificial intelligence (GAI) method, namely diffusion model (DM), for mobile communications. First, a DM-driven communication architecture is proposed, which introduces two key paradigms, i.e., conditional DM and DMdriven deep reinforcement learning (DRL), for wire...

Recently, there has been a growing interest in learning-based semantic communication because it can prioritize the preservation of meaningful semantic information over the accuracy of the transmitted symbols, resulting in improved communication efficiency. However, existing learning-based approaches still face limitations in defining semantic level...

With the development of intelligent connected vehicles, vehicular edge computing (VEC) systems can provide them with low latency and low energy consumption of task computation and data processing. In this paper, we propose a VEC-aided computing system by offloading tasks from vehicles to the edge computing node via the road side units (RSUs) to imp...

Symbiotic chirp-ultra wide bandwidth (UWB) radio system (SCURS) is a UWB radio system with the symbiosis of linear frequency modulation (LFM) and orthogonal frequency division multiplexing (OFDM) signals. It has a high data rate and can transmit data on two channels simultaneously. Moreover, multi-component LFM (MCLFM) parameter estimation plays an...

Ambient backscatter communication (AmBC) possesses signal reception and energy-harvesting capabilities, allowing providing wireless cognition through simple energy detection. In typical applications like industrial Internet of Things (IoT), cognitive AmBC (CAmBC) networks are required to offer passive communication, edge computing, and cognition ca...

Orthogonal time frequency space (OTFS) modulation, combined with massive multiple-input multiple-output (MIMO) technology, offers robust performance in high-mobility environments and high user densities by capturing the full diversity of the wireless channel and effectively utilizing spatial multiplexing. This paper introduces an adaptive block spa...

In this paper, the considered mutualistic symbiotic backscatter communication system comprises a base station (BS), a receiver (R) and multiple spatially randomized tags positioned within a circular area centered around R. In each transmission, BS transmits the information to R, while one selected tag also conveys its own information to R by modula...

Satellite-ground twin networks are considered a promising network structure, which can relieve network congestion and provide pervasive intelligent services. Since massive terrestrial users are not willing to share mobile data, it is necessary to design a novel security authentication method. In this paper, we consider a two-layer Stackelberg game...

Integrated sensing and communication (ISAC) is a pivotal technology for future sixth-generation (6G) communications. It aggregates wireless sensing and communication functionalities into one system while sharing spatial, temporal, and frequency resources. In this article, a review on artificial intelligence (AI)-enhanced ISAC is provided, by introd...

Wi-Fi is a very common means for providing wireless access to the Internet, e.g., using the 2.4GHz Industrial, Scientific, and Medical (ISM) band and more recently also the 6 GHz band via Wi-Fi 6E. Thanks to a chip recently launched by Semtech, in the same 2.4GHz band now can also operate Long Range (LoRa), which is widely used in Internet of Thing...

Downlink reconfigurable intelligent surface (RIS)-assisted multi-input-multi-output (MIMO) systems are considered with far-field, near-field, and hybrid-far-near-field channels. According to the angular or distance information contained in the received signals, 1) a distance-based codebook is designed for near-field MIMO channels, based on which a...

As the number of users connected to communication networks such as cellular networks and Internet of Things (IoT) networks increases, massive multiple-input multiple-output (MIMO) technique has been widely adopted to improve the spectral and energy efficiency. However, the multi-user frequency synchronization problem must be solved before channel e...

To address the power and computation limitations of the Internet-of-Things (IoT) devices, this letter investigates integrating wireless power transfer (WPT) and mobile edge computing (MEC) with intelligent reflective surfaces (IRS) in 6G networks. An optimization problem is formulated to minimize the energy consumption of the access point (AP) for...

Upon the arrival of emerging devices, including Extended Reality (XR) and Unmanned Aerial Vehicles (UAVs), the traditional communication framework is approaching Shannon's physical capacity limit and fails to guarantee the massive amount of transmission within latency requirements. By jointly exploiting the context of data and its importance to the...

This article targets at unlocking the potentials of a class of prominent generative artificial intelligence (GAI) method, namely diffusion model (DM), for mobile communications. First, a DM-driven communication architecture is proposed, which introduces two key paradigms, i.e., conditional DM and DM-driven deep reinforcement learning (DRL), for wir...

The continuous aperture array (CAPA) can provide higher degree-of-freedom and spatial resolution than the spatially discrete array (SDPA), where optimizing multi-user current distributions in CAPA systems is crucial but challenging. The challenge arises from solving non-convex functional optimization problems without closed-form objective functions...

Federated learning (FL) is an efficient and privacy-preserving distributed learning paradigm that enables massive edge devices to train machine learning models collaboratively. Although various communication schemes have been proposed to expedite the FL process in resource-limited wireless networks, the unreliable nature of wireless channels was le...

By leveraging massive available data and hidden communication patterns, deep learning (DL) has enabled diverse applications in wireless network operations. In this paper, we consider radar-aided beam prediction in multi-input multi-output (MIMO) communication systems with federated transfer learning (FTL) to preserve users' location privacy. Specif...

Matrix-variate optimization plays a central role in advanced wireless system designs. In this paper, we aim to explore optimal solutions of matrix variables under two special structure constraints using complex matrix derivatives, including diagonal structure constraints and constant modulus constraints, both of which are closely related to the sta...

Signal identification, a vital task of intelligent communication radios, finds its applications in various military and civil communication systems. Previous works on identification for space-time block codes (STBC) of multiple-input multiple-output (MIMO) system employing orthogonal frequency division multiplexing (OFDM) are limited to additive wh...

This letter investigates the effect of an extremely large (XL) simultaneously transmitting and reflecting intelligent reconfigurable surface (STAR-RIS) on the sum rate of the uplink nonorthogonal multiple access (NOMA). For the XL-STAR-RIS supporting NOMA in energy-splitting mode, we develop a sum rate maximization algorithm under the minimum rate...

Owing to the heterogeneous computation and communication capabilities among clients, the synchronous model aggregation in wireless federated learning (FL) is susceptible to the straggler effect and exhibits low learning efficiency, while asynchronous aggregation encounters delayed gradients that lead to convergence errors and learning performance d...

A novel accelerated mobile edge generation (MEG) framework is proposed for generating high-resolution images on mobile devices. Exploiting a large-scale latent diffusion model (LDM) distributed across edge server (ES) and user equipment (UE), cost-efficient artificial intelligence generated content (AIGC) is achieved by transmitting low-dimensional...

A double self-sustainable reconfigurable intelligent surfaces (RISs) assisted multi-user multiple input multiple output (MIMO) system is investigated, where two RISs are equipped with energy harvesting circuit to achieve self-sustainable transmission. We aim to minimize the transmission power at the base station (BS), while guaranteeing the quality...

Fingerprint-based indoor localization holds great potential for the Internet of Things. Despite numerous studies focusing on its algorithmic and practical aspects, a notable gap exists in theoretical performance analysis in this domain. This article aims to bridge this gap by deriving several lower bounds and approximations of mean square error (MS...

Cooperative caching has emerged as an efficient way to alleviate backhaul traffic and enhance user experience by proactively prefetching popular videos at the network edge. However, it is challenging to achieve the optimal design of video caching, sharing, and delivery within storage-limited edge networks due to the growing diversity of videos, unp...

Reconfigurable intelligent surface (RIS), by intelligently manipulating the incident waveform, offers a spectral and energy efficient capability for improving sensing and communication performance. In this article, we introduce a novel concept of RIS-assisted integrated sensing and backscatter communication (ISABC) system, by introducing RIS as eit...

In this letter, we design a federated contrastive learning (FedCL) framework aimed at supporting personalized semantic communication. Our FedCL enables collaborative training of local semantic encoders across multiple clients and a global semantic decoder owned by the base station. This framework supports heterogeneous semantic encoders since it do...

In this letter, we design a federated contrastive learning (FedCL) framework aimed at supporting personalized semantic communication. Our FedCL enables collaborative training of local semantic encoders across multiple clients and a global semantic decoder owned by the base station. This framework supports heterogeneous semantic encoders since it do...

This paper investigates covert communication in simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted non-orthogonal multiple access (NOMA) systems, assuming for the sake of being more practical that the successive interference cancellation (SIC) is defective. To assess the covertness performance of the c...

In this paper, we design a resource block (RB) oriented power pool (PP) for semi-grant-free non-orthogonal multiple access (SGF-NOMA) in the presence of residual errors resulting from imperfect successive interference cancellation (SIC). In the proposed method, the BS allocates one orthogonal RB to each grant-based (GB) user, and determines the acc...

Satellite-ground integrated networks (SGINs) are regarded as promising architectures for sensing heterogenous measurements, reducing network congestion and for providing pervasive intelligence services in support of terrestrial users. In SGINs, both low, medium and geostationary orbit based satellites are deployed for achieving global coverage and...

The data heterogeneity across clients and the limited communication resources, e.g., bandwidth and energy, are two of the main bottlenecks for wireless federated learning (FL). To tackle these challenges, we first devise a novel FL framework with partial model aggregation (PMA). This approach aggregates the lower layers of neural networks, responsi...

Low-resolution architectures represent a compelling and power-efficient approach for high-bandwidth communication in massive multiple-input multiple-output (MIMO) systems. In this letter, we present a novel residual convolutional neural network (CNN) with recurrent neural network (RNN) called ResR model to tackle the carrier frequency offset (CFO)...

In this paper, we consider an reconfigurable intelligent surface (RIS)-assisted multiple input single output (MISO) covert symbiotic radio (SR) communication system. RIS, as a secondary transmitter (STx), can enhance primary transmission from the primary transmitter (PTx) to the primary receiver (PRx). Simultaneously, STx transmits its own informat...

Satellite-ground integrated heterogeneous networks can relieve network congestion, release network resources and provide ubiquitous intelligence services for terrestrial users. Furthermore, digital twin technology can enable nearly-instant data mapping from the physical world to digital systems. The integration between satellite-ground integrated h...

Satellite-ground integrated networks (SGINs) are regarded as promising architectures for sensing heterogenous measurements, reducing network congestion and for providing pervasive intelligence services in support of terrestrial users. In SGINs, both low, medium and geostationary orbit based satellites are deployed for achieving global coverage and...

The upcoming sixth generation (6G) driven Internetof- Things (IoT) will face the great challenges of extremely low power demand, high transmission reliability and massive connectivities. To meet these requirements, we propose a novel hybrid ambient backscatter communication (ABCom) or relay communication (RCom) assisted non-orthogonal multiple acce...

At the network edges, the multi-tier computing framework provides mobile users with efficient cloud-like computing and signal processing capabilities. Deploying digital twins in the multi-tier computing system helps to realize ultra-reliable and low-latency interactions between users and their virtual objects. Considering users in the system may ro...

Multi-access Edge Computing (MEC) has been recognized as a key enabler for next-generation networks in supporting a large variety of compelling applications with challenging requirements. With its widely proved strength and successes, AI has to become an integral part of MEC. In this paper, we present a novel open-source edge AI (OpenEAI) framework...

Driven by the ever-increasing requirements of ultrahigh spectral efficiency, ultralow latency, and massive connectivity, the forefront of wireless research calls for the design of advanced next-generation multiple access schemes to facilitate the provisioning of these stringent demands. This inspires the embrace of nonorthogonal multiple access (NO...

This paper investigates a reconfigurable intelligent surface (RIS)-assisted wireless powered mobile edge computing (MEC) system, where an access point (AP) integrated with an MEC server first transmits energy signals to charge multiple energy-constrained devices in the downlink (DL), and then the devices utilize the harvested energy to perform MEC...

The wide coverage and broadcasting characteristics of satellite communications lead to multi-beam downlinks being vulnerable to security threats, such as eavesdropping, hacking and illegal access. This paper takes into account the case of multiple users and an eavesdropper (Eve) in the target beam. In particular, we consider the deployment of an un...

The Internet is the most complex machine humankind has ever built, and thus, it is difficult to defend it from attacks. The most common attack to the Internet is DDoS attacks. With the growing popularity for QUIC protocol, DDoS detection tasks are increasingly rely on machine learning (ML), which is based on black-box model and cannot explain its d...

Reconfigurable intelligent surface (RIS) has the potential to significantly enhance the physical layer security by reconfiguring the wireless propagation environment. However, due to the hostile nature of potential eavesdroppers and the cascaded channel brought by the RIS, acquiring perfect channel state information (CSI) of the eavesdroppers is ch...

As one of the most important metrics to sustainably provide communication services in green Industrial Internet of Things (IIoT), the problem of improving energy efficiency has constantly attracted extraordinary concerns from industry so far as to academia. In this paper, we intend to investigate the energy efficiency issue for an Energy Harvesting...

In this paper, we investigate signal detection in emerging dynamic spatial modulation (DSM) based MIMO systems, where the existing mapping and detection methods do not work efficiently. In order to address this issue, we begin by proposing a combinatorial mapping-based DSM (CM-DSM) scheme in this paper. The proposed CM-DSM scheme employs a combinat...

In 5G and beyond, UAVs are integrated into cellular networks as new aerial mobile users to support many applications and provide higher probability of line-of-sight (LoS) transmission to base stations (BSs). Nevertheless, due to limited frequency bandwidth and spectrum resource reuse when BSs serving terrestrial users (TUEs) and UAVs, it causes sev...

Performance analysis is carried out in a near-field multiple-input multiple-output (MIMO) system for both discrete and continuous aperture antennas. The effective degrees of freedom (EDoF) is first derived. It is shown that near-field MIMO systems have a higher EDoF than free-space far-field ones. Additionally, the near-field EDoF further depends o...

Most existing wireless federated learning (FL) studies focused on homogeneous model settings where devices train identical local models. In this setting, the devices with poor communication and computation capabilities may delay the global model update and degrade the performance of FL. Moreover, in the homogenous model settings, the scale of the g...

Traditional physical-layer receivers are typically composed of step-by-step serial processing modules heavily relying on complex hardware implementations and algorithms, where the optimal global performance cannot be guaranteed. In addition, system noise degrades the reliability of each module, resulting in the cumulative effect of errors. In this...

Reconfigurable intelligent surface (RIS) has the capability to significantly enhance physical layer security by recon-figuring the propagation in wireless communications. However, due to the cascaded channel brought by the RIS and the hostile nature of potential eavesdroppers, acquiring perfect channel state information (CSI) of the eavesdroppers i...

In recent years, more and more attention has been paid to the unmanned aerial vehicle (UAV) cooperative task assignment. In order to complete the task with the lowest cost, some researchers use multi-objective optimization to solve the assignment problem. But few of them consider the complex dynamic scenarios. In this article, the time-varying reso...

Future wireless networks will need to improve adaptive resource allocation and decision-making to handle the increasing number of intelligent devices. Unmanned aerial vehicles (UAVs) are being explored for their potential in real-time decision-making. Moreover, cognitive non-orthogonal multiple access (Cognitive-NOMA) is envisioned as a remedy to a...

In this paper, we consider an unmanned aerial vehicle (UAV)-enabled massive multiple-input multiple-out (MIMO) non-orthogonal multiple access (NOMA) full-duplex (FD) two-way relay (TWR) system with low-resolution analog-to-digital converters/digital-to-analog converters (ADCs/DACs), where the UAV provide services for multi-pair ground users (GUs)....

In this paper, it is investigated a multi-user multipleinput single-output wireless communication scenario (MISO) in which a base station (BS) serves multiple users with the assistance of a reconfigurable intelligent surface (RIS). Specifically, the delay sensitivity QoS aware total effective capacity (TEC) is maximized. By employing Zero-Forcing (...

Given the surge in wireless data traffic driven by the emerging Internet of Things (IoT), unmanned aerial vehicles (UAVs), cognitive radio (CR), and non-orthogonal multiple access (NOMA) have been recognized as promising techniques to overcome massive connectivity issues. As a result, there is an increasing need to intelligently improve the channel...

Satellite-high altitude platform (HAP)-terrestrial networks have been considered as an indispensable infrastructure of next-generation networks because they can offer massive access service with high throughput and broad coverage connections. Meanwhile, non-orthogonal multiple access (NOMA) and two-way relaying techniques are considered as potentia...