Reconfigurable intelligent surface (RIS) assisted non-orthogonal multiple access (NOMA) transmission can effectively improve the energy/spectrum efficiency in wireless networks. This paper designs a low-complexity scheme to achieve balanced tradeoff between sum-rate and power consumption RIS-assisted NOMA system, which be measured by energy efficiency. To solve formulated problem effectively, o...

In this paper, the performance and system complexity of the candidate multiple access (MA) techniques for the next generation of cellular systems, namely, non-orthogonal multiple access (NOMA) (in this paper, we consider power domain MA as NOMA) and sparse code multiple access (SCMA), are investigated. To this end, for each MA technique, a resource allocation problem considering heterogeneous c...

Intelligent reflecting surfaces (IRS) have recently been regarded as having potential for supporting multi-user (MU) multiple-input single-output (MISO) ultra-reliable and low-latency communication (URLLC) by creating favorable wireless links in the industrial IoT (IIoT) scenario. Hence, we studied joint robust design of a beamformer at central controller (CC) phase shifters IRS minimizing tran...

In this letter, we aim to maximize the minimum data volume for energy harvest (EH)-based D2D communication underlaying cellular network. The formulated problem is a mixed integer nonlinear programming (MINLP), which split into two sub-problems solve separately. We first employ Successive Convex Approximation (SCA) method time and power allocation, while putting spectrum multiplexed pairs as fix...

In this paper, we investigate a private and cache-enabled unmanned aerial vehicle (UAV) network for content provision. Aiming at delivering fresh, fair, energy-efficient files to terrestrial users, formulate joint UAV caching, trajectory, transmit power optimization problem. This problem is confirmed be sequential decision with mixed-integer non-convex constraints, which intractable directly. T...

The main difficulty concerning optimizing the mutual information (MI) in reconfigurable intelligent surface (RIS)-aided communication systems with discrete signaling is inability to formulate this optimization problem an analytically tractable manner. Therefore, we propose use cutoff rate (CR) as a more metric for MI and introduce two methods maximize CR, assuming perfect knowledge of channel s...

In this paper, we investigate secure transmissions in integrated satellite-terrestrial communications and the green interference based symbiotic security scheme is proposed. Particularly, co-channel induced by spectrum sharing between satellite terrestrial networks inter-beam due to frequency reuse among multi-beam serve as assist transmission, where of both links are guaranteed simultaneously....

The fundamental challenge of the millimeter-wave (mmWave) frequency band is sensitivity radio channel to blockages, which gives rise unstable connectivity and impacts reliability a system. To this end, multi-point promising approach for ensuring desired rate requirements. A robust beamformer design proposed improve communication by exploiting spatial macro-diversity pessimistic estimate rates o...

In this article, we investigate multiple unmanned aerial vehicles (UAVs)-enabled data collection system in Internet of Things (IoT) networks with time windows, where rotary-wing UAVs are dispatched to collect from time-constrained terrestrial IoT devices. We aim jointly minimize the number and total operation by optimizing UAV trajectory hovering location. To end, an optimization problem is for...