Ali Rahmati

TL;DR: This paper presents a detailed survey on the emerging technologies to achieve low latency communications considering three different solution domains: 1) RAN; 2) core network; and 3) caching.

TL;DR: This work investigates the energy efficiency of the RSMA and NOMA schemes in a millimeter-wave (mmWave) downlink transmission scenario and indicates that RSMA is superior to N OMA in terms of overall energy efficiency.

TL;DR: The results show that the proposed method significantly improves the detection performance in cooperative spectrum sensing and highly decreases the probability of miss-detection in comparison with the traditional energy detection method.

TL;DR: This letter considers the uplink of a co-channel framework where a macrocell shares the orthogonal frequency division multiple access (OFDMA) sub-channels with a number of small cells (SCs) and maximize the weighted sum-rate of the OFDMA SC network.

Abstract: We consider unmanned aerial vehicle (UAV)-assisted wireless communication employing UAVs as relays to increase the throughput between a pair of transmitter and receiver. We focus on developing effective methods to position the UAV(s) in the presence of interference in the environment, the existence of which makes the problem non-trivial and our methodology different from the current art. We study the optimal position planning, which aims to maximize the (average) signal-to-interference-ratio (SIR) of the system, in the presence of: i) one major source of interference, ii) stochastic interference. For each scenario, we first consider utilizing a single UAV in the dual-hop relay mode and determine its optimal position. Afterward, multiple UAVs in the multi-hop relay mode are considered, for which we investigate two novel problems concerned with determining the optimal number of required UAVs and developing an optimal distributed position alignment method. Subsequently, we propose a cost-effective method that simultaneously minimizes the number of UAVs and determines their optimal positions to guarantee a certain (average) SIR of the system. Alternatively, for a given number of UAVs, we develop a fully distributed placement algorithm along with its performance guarantee. Numerical simulations are provided to evaluate the performance of our proposed methods.