Non-orthogonal multiple access (NOMA) systems have the potential to deliver higher system throughput, compared contemporary orthogonal techniques. For a linearly precoded multiple-input multiple-output (MISO) system, we study downlink sum rate maximization problem, when NOMA principles are applied. Being non-convex and intractable optimization problem,we resort approximate it with minorization-maximization algorithm (MMA), which is widely used tool in statistics. In each step of MMA, solve...

We investigate the problem of downlink physical layer multicasting that aims at minimizing transmit power with a massive antenna array installed transmitter site. take solution based on semidefinite relaxation (SDR) as our benchmark. It is shown instead working program (SDP) naturally produced by SDR, dual counterpart same may provide more efficient numerical implementation. Later, using successive convex approximation strategy, we arrive provably convergent iterative second-order cone...

The problem of maximizing weighted sum rates in the downlink a multicell environment is considerable interest. Unfortunately, this known to be NP-hard. For case multi-antenna base stations and single antenna mobile terminals, we devise low complexity, fast provably convergent algorithm that locally optimizes rate system. In particular, derive an iterative second-order cone program formulation maximization problem. converges local optimum within few iterations. Superior performance proposed...

In the article, we establish an inequality for Csiszár divergence associated with s-convex functions, present several inequalities Kullback–Leibler, Renyi, Hellinger, Chi-square, Jeffery's, and variational distance divergences by using particular functions in divergence. We also provide new bounds Bhattacharyya

Accurate solar irradiance (SI) prediction is vital for optimizing photovoltaic systems. This study addresses shortcomings in existing forecasting methods by exploring advanced machine-learning techniques using meteorological satellite data. We develop three novel models SI forecasting: Stack-based Ensemble Fusion with Meta-Neural Network (SEFMNN), Extreme Gradient Boosting-Squared Error (XGB-SE), and Learning Machine (ELM). These predict All-sky Clear-sky shortwave across Chinese provinces...

In this paper, we propose two solutions to the problem of joint transmit-receive antenna selection in a multiple-input multiple-output (MIMO) cognitive radio (CR) system. Our objective is maximize CR data rates and satisfy interference constraints at primary user (PU) receiver(s). first approximate original non-convex optimization using an iterative approach solving series smaller convex problems. Second present novel, norm-based transmit receive technique that simultaneously improves...

Revived interest in physical layer security has led to a cascade of information theoretic results for various system topologies under different constraints. In the present paper, we provide practically oriented solutions problem maximizing achievable secrecy rates an environment consisting multiple legitimate and eavesdropping radio nodes. By assuming "genie" aided perfect channel state (CSI) feedback both types nodes, first study two scenarios interest. When independent messages are...

The important problem of weighted sum rate maximization (WSRM) in a multicellular environment is intrinsically sensitive to channel estimation errors. In this paper, we study ways maximize the linearly precoded downlink system where receivers are equipped with single antenna. With perfect information available at base stations, first present novel fast converging algorithm that solves WSRM problem. Then, assumption relaxed case error vectors estimates assumed lie an uncertainty set formed by...

In this paper we consider the capacity of cognitive radio (CR) channel in different fading environments under a "low interference regime". First derive probability that regime" holds shadow as well Rayleigh and Rician fast conditions. We demonstrate is dominant case, especially certain practical CR deployment scenarios. The depends critically on power loss parameter, ¿, which governs how much transmit dedicates to relaying primary message. simple, accurate approximation ¿ gives considerable...

We address the problem of downlink beamformer design for signal-to-interference-plus-noise ratio (SINR) balancing in a multiuser multicell environment with imperfectly estimated channels at base stations (BSs). first present semidefinite program (SDP) based approximate solution to problem. Then, as our main contribution, by exploiting some properties robust counterpart optimization problem, we arrive second-order cone (SOCP) approximation The advantages proposed SOCP-based are twofold....

In this paper we describe a model for calculating the aggregate interference encountered by primary receivers in presence of randomly placed cognitive radios (CRs). We show that incorporating impact distance attenuation and lognormal fading on each constituent interferer aggregate, leads to composite cannot be satisfactorily modeled lognormal. Using statistics determine number key parameters needed deployment CRs. Examples these are exclusion zone radius, protect receiver under different...

Generalized singular-value decomposition (GSVD) has been recognized as an enabler of multiple-input-multiple-output (MIMO) nonorthogonal multiple-access (NOMA) systems. The GSVD is leveraged to MIMO-NOMA with channel estimation errors. Channel uncertainty uniquely incorporated in the variances elements error matrices signal-to-interference-plus-noise ratio (SINR) balancing problem, and tractable convex formulations are derived for different models this letter. proposed design numerically...

To mitigate the computational power gap between network core and edges, mobile edge computing (MEC) is poised to play a fundamental role in future generations of wireless networks. In this correspondence, we consider non-orthogonal multiple access (NOMA) transmission model maximize worst task be offloaded among all users server. A provably convergent efficient algorithm developed solve considered non-convex optimization problem for maximizing minimum number bits multi-user NOMA-MEC system....

Weighted sums of Rayleigh random variables occur in diverse problems wireless, and particularly interference systems. Previous work has reported upper bounds on the cumulative distribution function weighted sums. New lower to are derived. The new used as an intermediate result deriving a bound ratio variable sum shifted by nonnegative constant. Special cases this context cognitive radio systems synchronization components. Novel approximations, that tighter than any known bounds, also presented.

Solar energy (SE) is vital for renewable generation, but its natural fluctuations present difficulties in maintaining grid stability and planning. Accurate forecasting of solar irradiance (SI) essential to address these challenges. The current research presents an innovative approach named as Transformer-Infused Recurrent Neural Network (TIR) model. This model integrates a Bi-Directional Long Short-Term Memory (BiLSTM) network encoding Gated Unit (GRU) decoding, incorporating attention...

The future deployment of cognitive radios (CRs) is critically dependent on the fact that incumbent primary user (PU) system must remain as oblivious possible to their presence. This in turn heavily relies fluctuations interfering CR signals. In this letter we compute level crossing rates (LCRs) cumulative interference created by CRs. We derive analytical formulae for LCRs Rayleigh and Rician fast fading conditions. approximate using fluctuation gamma scaled noncentral x <sup...

In this paper we describe the effect of imperfections in radio environment map (REM) information on performance cognitive (CR) systems. Via simulations explore relationship between required precision REM and various channel/system properties. For example, degree spatial correlation shadow fading is a key factor as interference constraint employed by primary user. Based CR interferers obtained from simulations, characterize temporal behavior such systems computing level crossing rates (LCRs)...

With the ever increasing interest in multiple-input multiple-output (MIMO) cognitive radio (CR) systems, reducing costs associated with RF-chains at front end becomes a very important factor. In this paper, we propose two solutions to problem of joint transmit-receive antenna selection objective maximizing data rates and satisfying interference constraints primary user (PU) receiver. first method approximate original non-convex optimization an iterative way solving series smaller convex...

Dynamic network architectures (DNAs) have been developed under the assumption that some terminals can be converted into temporary access points (APs) anytime when connected to Internet. In this paper, we consider problem of assigning a group users set potential APs with aim maximize downlink system throughput DNA networks, subject total transmit power and users' quality service (QoS) constraints. our first method, relax integer optimization variables continuous. The resulting non-convex...

In this paper we consider the problem of signal-to-interference-plus-noise ratio (SINR) balancing in downlink cognitive radio (CR) networks while simultaneously keeping interference levels at primary user (PU) receivers (RXs) below an acceptable threshold with uncertain channel state informat

The several standard and the existing proposed methods for optimality of transportation problems in linear programming problem are available. In this paper, we considered all then a new method optimal solution problems. most attractive feature is that it requires very simple arithmetical logical calculation, that’s why easy even layman to understand use. Some limitations recommendations future works also mentioned method. Several numerical examples have been illustrated, those gives clear...

The authors deal with the issues of statistical modelling aggregate interference because cognitive radios (CRs) at primary users and deployment CR systems in real world environments. explore possibilities by two- three-parameter log-normal distributions. find that traditional approach using a two-parameter log normal is not suitable option on account massive skewness difference between actual variable used for fitting purposes. Similarly, observe recently proposed approximation works only...

We develop a novel technique to accelerate minorization-maximization (MM) procedure for the non-orthogonal multiple access (NOMA) weighted sum rate maximization problem. Specifically, we exploit Lipschitz continuity of gradient objective function adaptively update MM algorithm. With fewer additional analysis variables and low complexity second-order cone program (SOCP) solve in each iteration algorithm, proposed approach converges quickly at small computational cost. By numerical simulation...

Hot-carrier solar cells (HCSCs) are one option for achieving solar-energy conversion more efficiently than conventional single-junction cells. Due to challenging material requirements, the development of HCSCs has been limited proof-of-concept devices. By examining heat flow in HCSCs, this study suggests expanding their characterization include carrier temperatures various contact configurations and biases. The authors show that hotter is not always better: High may be a sign excessively...