Kandeepan Sithamparanathan

• RMIT University

Cooperative spectrum sensing (CSS) is essential for improving the spectrum efficiency and reliability of cognitive radio applications. Next-generation wireless communication networks increasingly employ uniform planar arrays (UPA) due to their ability to steer beamformers towards desired directions, mitigating interference and eavesdropping. Howeve...

Optical wireless communications (OWCs) provide a promising alternative to current spectrum‐congested microwave wireless communications by directly transmitting data‐modulated lightwave in the free space. Due to the broad unregulated bandwidth, high‐speed data transmissions are achieved. However, direct line‐of‐sight links are required in OWC system...

The radio frequency (RF) spectrum is a scarce natural resource utilized by terrestrial and satellite systems that operate in regulated frequency bands. The sharing of this scarce resource and the bandwidth of these systems has led to various types of interferences including, narrowband interference (NBI) and wideband interference (WBI). The spectru...

The demand for spectrum access continues to grow exponentially and dynamic spectrum access (DSA) is a candidate to alleviate issues with spectrum scarcity by adapting spectrum resources in real-time. Despite the benefits of intelligent DSA protocols, many algorithms are complex thus prohibitively hard to be practically implemented in a real-time sy...

Transmitter authentication is critical for secured Internet of Things (IoT) applications. Recently, there has been growing interest in utilizing the physical layer authentication technique, radio frequency (RF) fingerprinting, to introduce extra security measurements without adding additional components. This work presents a novel fingerprint explo...

This paper presents an optimization approach for cooperative Medium Access Control (MAC) techniques in Vehicular Ad Hoc Networks (VANETs) equipped with multiple Roadside Units (RSUs) to enhance network throughput. We propose a distributed cooperative MAC scheme based on the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol....

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

p>This is a preprint of the paper, "Artificial Intelligence Techniques for Next-Generation Massive Satellite Networks".</p

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Devices authentication is one crucial aspect of any communication system. Recently, the physical layer approach radio frequency (RF) fingerprinting has gained increased interest as it provides an extra layer of security without requiring additional components. In this work, we propose an RF fingerprinting based transmitter authentication approach d...

Complementing RSSI measurements at anchors with onboard smartphone accelerometer measurements is a popular research direction to improve the accuracy of indoor localization systems. This can be performed at different levels; for example, many studies have used pedestrian dead reckoning (PDR) and a filtering method at the algorithm level for sensor...

Direction-of-arrival (DoA) estimation methods are highly versatile and find extensive applications in satellite communication. DoA methods are employed across a range of orbits, from low Earth orbits (LEO) to geostationary Earth orbits (GEO). They serve multiple applications, including altitude determination, geolocation and estimation accuracy, ta...

Passive bistatic radar research is essential for accurate 3D target tracking, especially in the presence of missing or low-quality bearing information. Traditional extended Kalman filter (EKF) methods often introduce bias in such scenarios. To overcome this limitation, we propose employing the unscented Kalman filter (UKF) for handling the nonlinea...

The Direction-of-Arrival (DoA) estimation methods are highly versatile and find extensive applications in satellite communication. The DoA methods are employed across a range of orbits, from Low Earth Orbits (LEO) to Geostationary Earth Orbits (GEO). They serve multiple applications, including altitude determination, geolocation and estimation accu...

The advent of the Internet of Things and 5G has further accelerated the growth in devices attempting to gain access to the wireless spectrum. A consequence of this has been the commensurate growth in spectrum conflict and congestion across the wireless spectrum, which has begun to impose a significant impost upon innovation in both the public and p...

Space communications, particularly massive satellite networks, re-emerged as an appealing candidate for next generation networks due to major advances in space launching, electronics, processing power, and miniaturization. However, massive satellite networks rely on numerous underlying and intertwined processes that cannot be truly captured using c...

p>This paper presents a practical approach for Q/V-band modeling for low Earth orbit satellite channels based on tools from machine learning and statistical modeling. The developed Q/V-band LEO satellite channel model is presented in two folds; (i) a real-time forecasting method using model-based deep learning, intended for real-time operation of s...

p>This paper presents a practical approach for Q/V-band modeling for low Earth orbit satellite channels based on tools from machine learning and statistical modeling. The developed Q/V-band LEO satellite channel model is presented in two folds; (i) a real-time forecasting method using model-based deep learning, intended for real-time operation of s...

Space communications, particularly mega satellite networks, re-emerged as an appealing candidate for next generation networks due to major advances in space launching, electronics, processing power, and miniaturization. However, mega satellite networks rely on numerous underlying and intertwined processes that cannot be truly captured using convent...

For the easy and flexible management of large scale networks, Software-Defined Networking (SDN) is a strong candidate technology that offers centralisation and programmable interfaces for making complex decisions in a dynamic and seamless manner. On the one hand, there are opportunities for individuals and businesses to build and improve services a...

Digital connectivity has become the foundation of prosperity and an essential need for functioning societies. Despite this dependence, limitation on Internet access remains a prevalent issue, largely hinging on socioeconomic and geographic factors. A promising solution to attain global access equality is based on integrated terrestrial-satellite ne...

The optical wireless communication (OWC) technology explores the broad unregulated optical spectrum to provide high-speed wireless communications, and the visible, ultraviolet and near-infrared wavelength ranges all have been investigated. Compared with the conventional radio frequency (RF) band, the spectrum in OWC systems is much less congested a...

Optical wireless communication (OWC) systems have been widely studied to provide high-speed connections in indoor environments. In this paper, we propose a filter-enhanced indoor OWC system with hybrid spatial modulation (SM) and spatial multiplexing (SMUX) to further increase the data rate. The filter-enhanced SM enables extra information be trans...

Anomalies could be the threats to the network that has ever/never happened. To detect and protect networks against malicious access is always challenging even though it has been studied for a long time. Due to the evolution of network in both new technologies and fast growth of connected devices, network attacks are getting versatile as well. Compa...

Radio Frequency (RF) fingerprinting is an emerging technology for advanced device authentication. In this work, we investigate the feasibility of utilizing three different types of fundamental waveform for the purpose of RF fingerprinting. The Short-time Fourier Transform (STFT) is adopted to exploit potential RF fingerprints, which results are the...

Denial of Service and Distributed Denial of Service (DoS/DDoS) attacks have been one of the biggest threats against communication networks and applications throughout the years. Modelling DoS/DDoS attacks is necessary to get a better understanding of their behaviour at each step of the attack process, from the Botnet recruitment up to the dynamics...

Digital connectivity has become the foundation of prosperity and an essential need for functioning societies. Despite this dependence, limitation on Internet access remains a prevalent issue, largely hinged on socioeconomic and geographic factors. A promising solution to attain global access equality is based on integrated terrestrial-satellite net...

During COVID-19 the new normal became an increased reliance on remote connectivity, and that fact is far away to change any time soon. The increasing number of networked devices connected to the Internet is causing an exponential growth of botnets. Subsequently, the number of DDoS (Distributed Denial of Service) attacks registered around the world...

Air-to-Ground (A2G) communication is considered as a significant enabler technology in next-generation networks. To make this a reality, a comprehensive understanding of the A2G channels is vital. This paper presents an Elevation Angle (EA) based two-ray mean path loss model for the A2G channels. In particular, we present closed-form expressions fo...

The widespread use of unmanned aerial vehicles (UAVs) has opened a novel perspective on spectrum awareness and localization because of their ability to overcome spatial limits and the burden of dedicated infrastructure. In such scenarios, an underinvestigated problem is the simultaneous localization of multiple non-collaborative primary users (PUs)...

Billions of sensors are expected to be connected to the Internet through the emerging Internet of Things (IoT) technologies. Many of these sensors will primarily be connected using wireless technologies powered using batteries as their sole energy source which makes it paramount to optimize their energy consumption. In this paper, we provide an ana...

Passive multistatic radars have gained a lot of interest in recent years as they offer many benefits contrary to conventional radars. Here in this research, our aim is detection of target in a passive multistatic radar system. The system contains a single transmitter and multiple spatially distributed receivers comprised of both the surveillance an...

In a distributed cognitive radio (CR) sensor network, transmission and reception on vacant channels require cognitive radio nodes to achieve rendezvous. Because of the lack of adequate assistance from the network environment, such as the central controller and other nodes, assisted rendezvous for distributed CR is inefficient in a dynamic network....

Many wireless Internet-of-Things applications require extended battery life ranging from a few months to a few years. Such applications have motivated the recent developments in low power wide area networks, including the rise of Long Range (LoRa) technology. LoRa has a simple modulation scheme designed for extended converge, low battery consumptio...

Software-Defined Networking (SDN) and Internet of Things (IoT) are the trends of network evolution. SDN mainly focuses on the upper level control and management of networks, while IoT aims to bring devices together to enable sharing and monitoring of real-time behaviours through network connectivity. On the one hand, IoT enables us to gather status...

The Internet of Things (IoT) enables the connectivity of massive numbers of sensors to facilitate the delivery of immense sets of data. This valuable data promotes higher productivity, effectiveness, and sustainability. With the accelerating global urbanization, many cities and suburbs are expected to face increasing challenges related to urban pla...

A vast adoption of wireless Internet of Things (IoT) network calls for reliable connectivity to support these large numbers of low-cost devices. The approach of frame-repetition is proposed by many IoT technologies to enhance the reliability in terms of coverage probability of wireless links. While the repetition scheme improves the chances of succ...

The Narrowband Internet of Things (NB-IoT) is one of the premier access technologies adopted by many telecom operators as the next-generation IoT solution. This technology is primarily designed to tackle the rapid growth of low-power IoT applications. However, NB-IoT runs in licensed frequency bands leased by the conventional telecom operators and...

The unique features of unmanned aerial vehicles (UAVs) extend a large number of existing technologies into environments that are not suitable for on-site operations. Localization, a critical basis of many applications such as cognitive radio and first response networks, can benefit from UAV technology as well. In such scenarios, an underinvestigate...

Delivering Internet-of-Things (IoT) connectivity over satellite is a promising solution for applications in remote and sparsely populated areas. These applications range from smart agriculture, logistics, asset tracking to emergency services. Using a shared radio spectrum with terrestrial services will facilitate a cost-effective and rapid deployme...

Billions of sensors are expected to be connected to the Internet through the emerging Internet of Things (IoT) technologies. Many of these sensors will primarily be connected using wireless technologies powered using batteries as their sole energy source which makes it paramount to optimize their energy consumption. In this paper, we provide an ana...

Directional antennas are regarded as one of the key technologies to achieve higher signal quality and data rate. Evidence has shown that the directional antenna channel features can be very different from the omnidirectional ones. Therefore, it is essential to characterize the directional antenna channel model (DACM), since an accurate, easy-to-imp...

Weighted centroid localization (WCL) based on received signal strength measurements is an attractive low-complexity solution that enables sensor networks to have a geolocation awareness of the radio environment. In this article, we propose an analytical framework to calculate the performance of WCL combining the Taylor series expansion of the logar...

The number of small sophisticated wireless sensors which share the electromagnetic spectrum is expected to grow rapidly over the next decade and interference between these sensors is anticipated to become a major challenge. In this paper we study the interference mechanisms in one such sensor, automotive radars, where our results are directly appli...

The raw data obtained for pulse modulating a K-MC3 radar module from RFbeam. The VCO of the radar module was controlled with a micro-controller with a DAC by switching between two voltage levels so that each frequency is retained for 3μs. This raw data is used for verifying the proposed model in the paper 'Interference Mitigation in Automotive Rada...

Over the recent past, the urban landscape has been shifting towards a new paradigm called ‘smart cities’. The smart city concept operates in a complex urban environment, incorporating several systems of infrastructure, human behaviour, technology, social and political structures and the economy. Practice gaps exist in achieving this model. Current...

Cognitive radio technology has shown tremendous potential through its spectrum access mechanism for reducing spectrum paucity. With the vacant spectrum, two nodes require consensus for common channel in an apposite time. However, in a non-centralised distributed communication system, the task of attaining one common channel for two nodes is not tra...

Cognitive radio networks are more susceptible to jamming attacks due to the nature of unlicensed users accessing the spectrum by performing dynamic spectrum access. In such a context, a natural concern for operators is the resilience of the system. We model such a scenario as one of adversity in the system consisting of a single legitimate (LU) pai...

The fifth-generation cellular networks (5G) has been proposed as a solution for the accelerating growth in data traffic. As part of 5G, millimetre-wave (mmWave) is suggested as one of the potential spectrum candidates due to the vastly available bandwidth. Accordingly, both indoor and outdoor propagation measurements on mmWave have been widely cond...

In the near future, a vast number of IoT devices are expected to join the Internet. Many of these devices are powered by battery as their sole energy source, where energy-efficiency is of utmost importance to prolong the lifespan of these devices over next generation networks. This paper proposes an energy-efficient framework for adaptively control...

Source localization of primary users (PUs) is a spectrum awareness feature that can be very useful in enhancing the functionality of cognitive radios (CRs). When the cooperating CRs have limited information about the PU, weighted centroid localization (WCL) based on received signal strength (RSS) measurements represents an attractive low-complexity...

ᅟ Spectrum scarcity due to inefficient utilisation has ignited a plethora of dynamic spectrum access solutions to accommodate the expanding demand for future wireless networks. Dynamic spectrum access systems allow secondary users to utilise spectrum bands owned by primary users if the resulting interference is kept below a pre-designated threshold...

Aerial platforms have recently gained a wide popularity as key enablers for rapid deployable wireless networks where coverage is provided by onboard radio heads. These platforms are capable of delivering essential wireless communications for public safety agencies during the aftermath of natural disasters, or to provide a rapid coverage patch in re...

Recent advances in semiconductor fabrication are providing the opportunity to build very small and cost-effective single chip integrated radar systems operating at millimeter-wave frequencies and beyond. These tiny radar systems will enable a wide range of new applications such as automotive radar, safety helmet radar, robot guidance radar, UAV col...

Stepped frequency radar technology, where the transmit waveform consists of a sequence of tones, has long been suggested for cost-effective and high-resolution applications. One recent use of this technology is in automotive application where, in addition to cost-effectiveness, a random stepped frequency (RSF) waveform can significantly reduce the...

As the use of automotive radar increases, performance limitations associated with radar-to-radar interference will become more significant. In this paper we employ tools from stochastic geometry to characterize the statistics of radar interference. Specifically, using two different models for vehicle spacial distributions, namely, a Poisson point p...

In this paper we provide an analytic framework for computing the expected downlink coverage probability, and the associated rate of cellular networks, where base stations are distributed in a random manner . The provided expressions are in computable integral forms that accommodate generic channel fading conditions. We develop these expressions by...