We are living in an era of virtual products, from virtual shopping stores to virtual reality, the cutting edge technology is changing the world the way we see and feel it. This ever growing and ever changing e-world places new requirements on the way we connect and communicate and sets new constraints on the next generation of wireless access i.e., 5G systems. The main goal of 5G system is to transform our society into hyper connected society in which mobile devices will play even more important role in shaping and improving the lives of a common man. The date rate demands of 5G systems when met with the scarce resources in spectrum of microwave, the result was rather disappointing and therefore it forced research community of both industry and academia to search for new horizons. And it didn’t took them long to come up with the solution in form of huge unused spectrum of millimeter wave (mmW).
Though the idea of using mmW is new in wireless communications but its history goes back to 1890s when J.C. Bose was experimenting with millimeter wave signals and just to have a good perspective about the time, it was the same era when Marconi were inventing radio communications. Therefore when it comes to the basic physics of mmW, we already know almost everything about it. As of today, 5G communication systems are comprised of a set of goals that must be achieved for future wireless networks. However, despite the lack of standards a few paths are foreseen to achieve those goals, such as,
In this context, it is of uttermost importance to be able to fully characterize the performance of the proposed technologies to determine how future networks will look like and to guide its deployment. The classical method to evaluate the system level performance of the coverage and rate of wireless networks always employ a regular deployment of the base stations and a hexagonal coverage area. This model has worked well enough so far but it presented shortcomings in face of the challenges of modern wireless networks. Firstly, this model is not scalable and does not allow for analytical results. Secondly, it does not represent faithfully the deployment patterns of modern networks. Currently our group is focusing on the following research objectives
Due to the exponential growth of personal data flow over wireless networks, information security is increasingly becoming a big concern when designing new communication systems. As shown in the figure, the private messages from the transmitters are exposed to the legitimate destinations, as well as to the malicious users (eavesdroppers), because of the shared nature of wireless medium. Henceforth, how to protect the private information from eavesdropping is our challenge. Such security issues are usually addressed by deploying encryption algorithms, key management schemes, fingerprints, attack detection and prevention at the upper layers. Unfortunately, such configuration are becoming more unreliable and hard to implement in the future networks with the rapid progress of computational devices. Inspired by such reality, an alternative or complement approach, termed as Physical layer security, takes advantages of the randomness and fading property of wireless channels to minimize the possibility of information leakage. Observed from the figure, one possible solution is to diminish the quality of the received signal at eavesdropper whilst increasing that of the intended receiver from the information theoretical perspective. Apart from that, plenty of researchers from the academia and industrial community are focusing on investigating how to enhance physical layer security from other perspectives, such as game theory, graph theory, etc. To this end, the core of this project is on the exploration of how to jam the eavesdroppers at reasonable prices. Specifically, we will deploy the existing promising techniques, such as beamforming, energy harvesting, and channel coding etc., for the purposing of designing the novel reliable and secure communication systems. On top of that, Shifting from physical layer security to medium access control and other upper layers, corresponding secrecy-enhancement behaviors should be well understood and designed to accommodate the use of secrecy-based physical layer transmission schemes. All in all, the security issues of many networks are awaiting for further analysis from the viewpoint of cross-layer designing.
Last mile access
Enterprise connectivity
Metro-network extensions
Service acceleration
Fiber backup
Telecom network extensions
Bridging WAN Access
Military access
Although FSO system has several advantages over conventional RF systems, this technology has to face several challenges due to random nature of the atmospheric channel. The signal in FSO link suffers due to various adverse effects (viz., absorption, scattering and turbulence) of the atmospheric channel. Although FSO link is relatively unaffected by rain and snow, but it is seriously affected due to fog and atmospheric turbulence. Both these factors lead to serious degradation in the link performance and make the communication link infeasible. The degrading effect of atmospheric channel can be improved by use of various mitigation techniques like aperture averaging, diversity, adaptive optics and coding.
Ongoing research in this area is focusing on following topics:
Adaptive optics
Channel correlation and diversity
Coded optical wireless links for space and underwater communication
Adaptive transmission in FSO systems
Relay assisted transmission in space and underwater optical communication
Hybrid RF/FSO system
Pointing and tracking requirements
Coherent and Non-coherent FSO systems
The Internet of Things is intended to offer wireless connections with multiple devices and sensors. Therefore, low latency, low complexity, low energy consumption, low data rate are important metrics that need to be fully or partially satisfied in several IoT applications. The concept of internet of things (IoT) is developed in parallel to the continuous progress in 5G networks by virtue of wireless sensor networks (WSN) that have emerged as the most promising technology for the future. And it is expected to touch various aspects of our life like fitness, automation, security, localization, consumer electronics, smart grid devices, and many more. In fact, WSNs have been among one of the most researched areas in the last decade. The emergence of this technology has only been possible via advances in and availability of small and inexpensive smart sensors that are cost effective and easily deployable. Various modulation schemes so far have been used in wireless sensor nodes, among these schemes are M-ary quadrature amplitude modulation (MQAM), offset quadrature phase-shift keying (OQPSK) and multiple frequency-shift keying (MFSK), which is also known as the green modulation scheme providing the advantage of low complexity and low cost of implementation. Our main goal in this research project is to design an alternative low-complexity, energy efficient, low latency, and/or low data rate secure modulation schemes which fit the requirements of both current and emerging wireless sensor networks. To achieve the aforementioned research goals, many research directions will be investigated. For example, we will exploit degrees of freedom that already exist in the wireless modem to carry extra bits without increasing the receiver’s complexity. Moreover, we will propose new non-coherent modulator schemes that exploit new waveforms to increase the robustness of the transmission, to enhance the spectral efficiency while keeping the implementation complexity of the system within its pragmatic limits. Therefore, a careful design of the transmitted signals in non-coherent communication techniques will be exploited in order to approach the channel capacity of coherent systems.
This research project aims to develop new techniques and algorithms to improve the precision of location by using multilateration technique. This technology is gaining popularity in radio navigation industry due to its high localization accuracy, flexibility, and low cost of deployment.
Memberships in groups and research laboratories
Laboratoire de communications et d'intégration de la microélectronique - LaCIME COMunité
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