Performance Evaluation of Adaptive Cooperative NOMA Protocol at Road Junctions

Vehicular communications (VCs) protocols offer useful contributions in the context of accident prevention thanks to the transmission of alert messages. This is even truer at road intersections since these areas exhibit higher collision risks and accidents rate. On the other hand, non-orthogonal multiple access (NOMA) has been show to be a suitable candidate for five generation (5G) of wireless systems. In this paper, we propose and evaluate the performance of VCs protocol at road intersections, named adaptive cooperative NOMA (ACN) protocol. The transmission occurs between a source and two destinations. The transmission is subject to interference originated from vehicles located on the roads. The positions of the interfering vehicles follow a Poison point process (PPP). First, we calculate the outage probability related to ACN protocol, and closed form expressions are obtained. Then we compare it with other existing protocols in the literature. We show that ACN protocol offers a significant improvement over the existing protocols in terms of outage probability, especially at the intersection. We show that the performance of ACN protocol increases compared to other existing protocols for high data rates. The theoretical results are verified with Monte-Carlo simulations

Interference modeling of wireless cooperative systems

The main goal of this thesis is to study the impact of interference on cooperative vehicular communications (VCs) with the aid of stochastic geometry tools. This thesis also proposes a framework to model interference in cooperative VCs. First, we study the effects of interference dependence on the received node for several transmission schemes, different channel models, and two mobility models. The performance in terms of outage probability is investigated. Second, we investigate the improvement of using non-orthogonal multiple access (NOMA) in the performance in terms of outage probability and average achievable rate for several transmission schemes. The results show that NOMA improves significantly the performance. We also investigate conditions in which NOMA outperforms OMA. Finally, studies are conducted: 1) an adaptive cooperative NOMA protocol is proposed, 2) an analysis of millimeter waves (mmWave) vehicular networks is carried out, 3) extension scenarios are investigated such as multiple relays, multiple hops, or multiples lanes

Second Order Statistics of -Fisher-Snedecor Distribution and Their Application to Burst Error Rate Analysis of Multi-Hop Communications

An advantage of using the composite fading models (CFMs) is their ability to concurrently address the impact of multi-path and shadowing phenomena on the system performance in wireless communications. A Fisher-Snedecor (FS) F CFM has been recently proposed as an experimentally verified and tractable fading model that can be efficiently applied for 5G and beyond 5G wireless communication systems. This paper provides second-order (s-order) performance analysis of the product of N independent but not identically distributed (i.n.i.d) FS F random variables (RVs). In particular, accurate and closedform approximations for level crossing rate (LCR) and average fade duration (AFD) of the product of N i.n.i.d FS F(N-FS F) RVs are successfully derived by exploiting a general property of a Laplace approximation method for evaluation of the N -folded integral-form LCR expression. Based on the obtained s-order statistical results, the burst error rate and maximum symbol rate of the N -FS F distribution are addressed and thoroughly examined. The numerical results of the considered performance measures are discussed in relation to the N-FS F multi-path and shadowing severity parameters. Moreover, the impact of the number of hops (N) of the N -FS F CFM on the s-order metrics, the burst error rate and maximum symbol rate are numerically evaluated and investigated. The derived s-order statistical results can be used to address the cooperative relay-assisted (RA) communications for vehicular systems. Monte-Carlo (M - C) simulations for the addressed statistical measures are developed in order to confirm the provided theoretical results.This work was supported in part by UC3M and the European Union's Horizon 2020 Programme under the Marie Sklodowska-Curie Grant through the CONEX-Plus Project under Agreement 801538; in part by the IRENE-EARTH Project under Grant PID2020-115323RB-C33/AEI/10.13039/501100011033; in part by ERDF and the Spanish Government Projects under Grant PID2019-106808RA-I00 AEI/FEDER, UE; in part by CDTI Cervera Project INTEGRA under Grant CER-20211031; in part by the Secretaria d'Universitats i Recerca de la Generalitat de Catalunya under Project 2017-SGR-00376 and Project Fem IoT under Grant 001-P-001662; in part by the European Commission Project CPSoSaware; and in part by the Cost Actions under Grant CA19111, Grant CA20120, and Grant CA16220.Publicad

Information-sharing outage-probability analysis of vehicular networks

In vehicular networks, information dissemination/sharing among vehicles is of salient importance. Although diverse mechanisms have been proposed in the existing literature, the related information credibility issues have not been investigated. Against this background, in this paper, we propose a credible information-sharing mechanism capable of ensuring that the vehicles do share genuine road traffic information (RTI). We commence with the outage-probability analysis of information sharing in vehicular networks under both a general scenario and a specific highway scenario. Closed-form expressions are derived for both scenarios, given the specific channel settings. Based on the outage-probability expressions, we formulate the utility of RTI sharing and design an algorithm for promoting the sharing of genuine RTI. To verify our theoretical analysis and the proposed mechanism, we invoke a real-world dataset containing the locations of Beijing taxis to conduct our simulations. Explicitly, our simulation results show that the spatial distribution of the vehicles obeys a Poisson point process (PPP), and our proposed credible RTI sharing mechanism is capable of ensuring that all vehicles indeed do share genuine RTI with each other

Downlink Performance of Optical Power Domain NOMA for Beyond 5G Enabled V2X Networks

In this work, we explore the potential benefits andpractical challenges associated with implementation of opticalpower domain non-orthogonal multiple access (OPD-NOMA)scheme for visible light communications (VLC) based vehicle-to-everything (V2X) networks with a major aim of providingvehicles with reliable, ubiquitous, and massive connectivity. Inthe proposed framework, an installed light source (e.g., trafficlamp post or street light lamp post) broadcasts a safety relatedmessage to desired nodes through visible light. However, suchVLC transmission is subject to interference originating fromthe vehicles in the adjacent lane. Using the stochastic geometryapproach, we model the locations of vehicles on the road via Pois-son point process. We investigate the applicability of downlinkOPD NOMA enabled V2X network for typical infrastructure-to-vehicle (I2V) communication in presence of interference causedfrom concurrent vehicle-to-vehicle (V2V) transmissions with anaid of stochastic geometry. Through the obtained results, it hasbeen shown that the downlink OPD NOMA based V2X networkoffers improved performance in terms of outage performanceand average achievable rate as compared to the conventional RFbased V2X communication