Supervision : Naceur MALOUCH
The next-generation communication systems such as LTE and LTE-Advanced, their performance is already close to the well-known Shannon bound in terms of spectrum efficiency! This motivates mobile operators to increase the capacity of their cellular networks by moving towards data traffic offloading from licensed to unlicensed spectrum which stands out as a promising solution. LTE in unlicensed spectrum has been proposed to extend the usual operation of LTE in licensed spectrum to cover also unlicensed spectrum. However, this extension poses significant challenges especially regarding the coexistence between LTE and Wi-Fi. The new entrant LTE should fairly coexist with the incumbent Wi-Fi so that LTE can be considered as Wi-Fi-friendly. Knowing that LTE and Wi-Fi were originally designed for different networking purposes, the heterogeneity between their both MAC and PHY layer are quite high, and thus, ensuring the fair coexistence is really a great challenge.
In this thesis, we are looking for studying deeply both LTE and Wi-Fi performance in different coexistence scenarios where LTE adopts one of the new four-MAC Layer protocols which were proposed for LTE in unlicensed spectrum by 3GPP. Our research approach is based on providing several analytical models that describe LTE/Wi-Fi interaction in detail with respect to the channel access. To further enhance LTE/Wi-Fi coexistence, LTE has also to tackle the problem that comes from its PHY layer heterogeneity with Wi-Fi PHY layer. We have presented a simple solution to tackle the previous problem based on adaptive adjustment of the energy detection threshold for both LTE and Wi-Fi.
Defence : 06/18/2018 - 14h30 - Site Jussieu 25-26/105
M. Mostafa Ammar, Professeur, Georgia Institute of Technology [Rapporteur]
Mme. Véronique Vèque, Professeur, Université Paris-Sud [Rapporteur]
M. André-Luc BEYLOT, Professeur, Université de Toulouse [Rapporteur]
M. Salah Eddine ELAYOUBI, Professeur, Ecole CentraleSupélec
Mme. Maria POTOP-BUTUCARU, Professeur, Sorbonne Université
M. Tijani CHAHED, Professeur, Ecole Telecom SudParis
M. Naceur Malouch, Maître de conférence (HDR), Sorbonne Université