In this letter, we investigate the outage performance of cooperative relaying transmissions in two-user non-orthogonal multiple access systems, wherein simultaneous wireless information and power transfer is employed at near users to their operations. To end, a best-near best-far (BNBF) user selection scheme proposed. Considering three protocols, i.e., decode-and-forward (DF), amplify-and-forward (AF), hybrid DF/AF tight closed-form approximate expressions for probability are derived...

In this paper, we study the statistical characterization and modeling of distributed multi-reconfigurable intelligent surface (RIS)-aided wireless systems. Specifically, consider a practical system model where RISs with different geometric sizes are distributively deployed, channels associated to assumed be independent but not identically (i.n.i.d.). We propose two purpose-oriented multi-RIS-aided schemes, namely, exhaustive RIS-aided (ERA) opportunistic (ORA) schemes. A mathematical...

This letter proposes highly accurate closed-form approximations to channel distributions of two different reconfigurable intelligent surface (RIS)-based wireless system setups, namely, dual-hop RIS-aided (RIS-DH) scheme and transmit (RIS-T) scheme. Differently from previous works, the proposed reveal be very tight for arbitrary number N reflecting metasurface's elements. Our findings are then applied performance analysis considered systems, in which outage probability, bit error rate,...

The so-called Internet of Vehicle (IoV) systems will interconnect numerous vehicles to communicate significant information through an Things (IoT) enabled network. It has emerged as a promising system wherein various data authentication techniques have been introduced using clumsy certificate management and Diffie-Hellman (DH) assumption. However, in the presence quantum cryptanalysis, DH-type problems could be solved polynomial-time. In this paper, novel certificateless protocol is...

In this correspondence, the outage probability (OP) of dual-hop cognitive amplify-and-forward (AF) relay networks subject to independent non-identically distributed (i.n.i.d.) Nakagami- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> fading is examined. We assume a spectrum-sharing environment, where two different strategies are proposed determine transmit powers secondary network. Specifically, power conditions network governed by either...

Three low-complexity relay-selection strategies, namely, selective amplify and forward (S-AF), decode (S-DF), with partial relay selection (PRS-AF) in a spectrum-sharing scenario are studied. First, we consider where perfect channel state information (CSI) is available. For these scenarios, the respective asymptotic outage behaviors of secondary systems analyzed, from which diversity coding gains derived compared. Unlike gain, shown to be very sensitive position primary receiver, gain system...

In this paper, we investigate the end-to-end performance of dual-hop relaying systems with beamforming over Nakagami-m fading channels. Our analysis considers semiblind (fixed-gain) relays single antennas, and source destination nodes equipped multiple antennas. Closed-form expressions for outage probability (OP), moment generating function (MGF), generalized moments signal-to-noise ratio (SNR) are derived. The proposed apply to general operating scenarios distinct Nakagamim parameters...

This paper investigates several important performance metrics of cognitive amplify-and-forward (AF) relay networks with a best selection strategy and subject to non-identical Rayleigh fading. In particular, assuming spectrum sharing environment consists one secondary user (SU) source, K SU relays, destination, primary (PU) receiver, closed-form expressions for the outage probability (OP), average symbol error (SEP), ergodic capacity network are derived. The correctness proposed analysis is...

In this paper, we study a hybrid satellite-terrestrial spectrum sharing system (HSTSSS) in which multiple terrestrial secondary networks cooperate with primary satellite network for dynamic access. For complexity-aware HSTSSS design, propose an amplify-and-forward-based overlay protocol using partial and opportunistic selection schemes. The aims to minimize the outage probability of and, thereby, explore opportunities. With approach, selected allocates part its power relay signal utilizes...

In this paper, we investigate the end-to-end performance of dual-hop proactive decode-and-forward relaying networks with Nth best relay selection in presence two practical deleterious effects: i) hardware impairment and ii) co-channel interference. particular, derive new exact asymptotic closed-form expressions for outage probability average channel capacity partial opportunistic schemes over Rayleigh fading channels. Insightful discussions are provided. It is shown that, when system cannot...

In this paper, we study the performance improvement methods for a cell-edge user of two-user non-orthogonal multiple access (NOMA) systems in downlink scenarios. To end, propose two cooperative relaying schemes, namely ON/OFF-full-duplex (ON/OFF-FDR) and ON/OFF-half-duplex (ON/OFF-HDR) schemes. More specifically, order to improve user, consider cell-center as relay, where either FDR or HDR can be employed assist direct NOMA transmission from base station (BS) user. An ON/OFF mechanism is...

In this letter, we investigate the outage performance of dual-hop decode-and-forward (DF) cooperative systems in an interference-limited Nakagami-m fading environment. More specifically, assuming presence faded multiple co-channel interferers at DF relay and a noisy destination, simple accurate closed-form approximations for end-to-end probability are derived. To end, moment-based estimators used to attain appropriate parameters. Simulation results presented order confirm accuracy proposed...

In this letter, we consider a network assisted by multiple reconfigurable intelligent surfaces (RISs). Assuming that the RIS with highest instantaneous end-to-end signal-to-noise ratio (SNR) is selected to aid communication, outage probability (OP) and average sum-rate are investigated. Specifically, an exact analysis for OP developed. addition, relying on extreme value theory, closed-form expression asymptotic derived, based which capacity scaling law established. Our results corroborated...

In this paper, the outage behavior of dual-hop multiuser multirelay cognitive radio networks under spectrum-sharing constraints is investigated. proposed network, secondary network composed one secondary-user (SU) source that communicates with out L destinations through a direct link and also via help N relays by using an efficient relay-destination selection scheme. Additionally, combining (SC) scheme to select best (direct or link) from SU employed at selected destination. Adopting...

Non‐orthogonal multiple access (NOMA) in amplify‐and‐forward relay systems with partial selection (PRS) is investigated. More specifically, new exact closed‐form expressions for the outage probabilities at two users are derived, based on which an asymptotic analysis high signal‐to‐noise ratio (SNR) carried out. Additionally, to investigate performance gap between NOMA and orthogonal (OMA) schemes, a approximate expression SNR sum rate derived. Furthermore, relying results, impact of PRS...

In this paper, we study the performance of a cell-edge user in two-user multiple-input single-output nonorthogonal multiple access (MISO-NOMA) system. Since outage and fairness data rate users are essential issues NOMA systems, focus on how to resolve such problems. To end, propose three cooperative downlink transmission schemes utilizing hybrid simultaneous wireless information power transfer (SWIPT) transmit antenna selection (TAS) protocols. Particularly, each scheme, cellcenter acts as...

This paper addresses multi-user multi-cluster massive multiple-input-multiple-output (MIMO) systems with non-orthogonal multiple access (NOMA). Assuming the downlink mode, and taking into consideration impact of imperfect successive interference cancellation (SIC), an in-depth analytical analysis is carried out, in which closed-form expressions for outage probability ergodic rates are derived. Subsequently, power allocation coefficients users within each sub-group optimized to maximize...

In this paper, we investigate the performance of a mixed radio-frequency-underwater wireless optical communication (RF-UWOC) system where an unmanned aerial vehicle (UAV), as low-altitude mobile base station, transmits information to autonomous underwater (AUV) through fixed-gain amplify-and-forward (AF) or decode-and-forward (DF) relay. The analysis accounts for main factors that affect performance, such UAV height, air bubbles, temperature gradient, water salinity variations, detection...

In this paper, a backscatter cooperation (BC) scheme is proposed for non-orthogonal multiple access (NOMA) downlink transmission. The key idea to the surplus power of received signals at one user enhance reception who cannot recover its information. To evaluate performance BC-NOMA scheme, three benchmark schemes are introduced, which include non-cooperation (NC)-NOMA conventional relaying (CR)-NOMA and incremental (IR)-NOMA scheme. For all these schemes, outage performance, expected rate,...

Intelligent reflecting surface (IRS), which is composed of a large number low-cost passive elements, has the ability to reflect incident signal independently with an adjustable phase and amplitude shifts, been regarded as key emerging technology for achieving cost-effectively spectrum addressing energy issues in next generation wireless networks. In this paper, we propose general wideband non-stationary channel model IRS-assisted multiple-input multiple-output (MIMO) communication scenarios,...

This paper studies the performance of intelligent reflecting surface (IRS)-aided short-packet non-orthogonal multiple access (NOMA) systems under perfect and imperfect successive interference cancellation. Closed-form expressions for average block error rate (BLER) with random optimal phase shifts are derived. To gain some useful insights, an asymptotic analysis is carried out, based on which diversity achieved. Numerical results show that, at high signal-to-noise ratio, users shift achieve...

Ultra-reliable low-latency communications (URLLCs) and the adoption of unmanned aerial vehicles (UAVs) for network coverage improvement have emerged as key enabling communication paradigms successful deployment mobile services envisioned in both fifth-generation (5G) sixth-generation (6G) networks. This paper provides a comprehensive survey about current state-of-the-art (SoA) on UAV-enabled URLLC The core idea is to highlight main characteristics this new concept well its critical aspects....

The authors describe a novel, direct technique for determining the small-signal equivalent circuit of heterojunction bipolar transistor (HBT). parasitic elements are largely determined from measurements test structures, reducing number transistor. intrinsic evaluated y-parameter data, which DC-embedded known parasitics. equivalent-circuit uniquely at any frequency. validity this is confirmed by showing frequency independence extracted elements. models HBT s-parameters over wide range...

Novel expressions for the average channel capacity (ACC) of single-branch receivers operating in generalized fading channels, namely eta-mu and kappa-mu, are derived. The written terms well-known Meijer's G-functions, which easily implemented most popular computing softwares. In addition, it is shown that, any given condition, Nakagami-m ACC defines regions capacity: lowerbounds upperbounds kappa-mu ACC. same way, alpha-mu alpha < 2 mu > m, m.