In this talk first we will discuss about the Carrier Frequency Offset estimation for the Inter-Uav communication. Drones or UAVs are widely used today for commercial as well as strategic purposes. When a large numbers of drones fly and maneuver together, the OFDM based communication links between drones would see time-varying Doppler. In particular, we study a measurement model where the Doppler variation is significant even within one OFDM block (symbol) duration. We approximately model the time variation of Doppler within one OFDM symbol as well as one whole frame and propose a low complexity timing correlation based algorithm. This approach exploits the repetition of the preamble symbol as well as the self similarity of the Cyclic Prefix(CP) to estimate the Doppler frequency, track the same throughout the frame. The proposed approach provides a far superior bit error rate performance in this time-varying Doppler models when compared to conventional schemes.



In the second part of the talk we will discuss about Age of Information (AoI) in cellular wireless networks under non-stationary regimes. We propose a new adversarial channel model for studying the scheduling problem in non-stationary environments. For N users, we have proposed a fundamental lower bound of the competitive ratio for any online scheduling policy in this setting. We then propose an online policy and show that it achieves a competitive ratio of O(N^2). Finally, we introduce a relaxed adversarial model with channel state estimations for the immediate future. We propose a heuristic model predictive control policy that exploits this feature and compare its performance through numerical simulations.