In this paper, we consider the problem of three-hop Free Space Optical (FSO) communications in the context of decode-and-forward (DF) buffer-aided (BA) relaying where the two relays are equipped with buffers of finite size. We adopt a Markov chain analysis for evaluating the outage probability (OP) and average packet delay (APD) of the considered serial relaying system that operates naturally in the

In this paper, we have derived stochastic geometry based generalised mathematical expressions for the uplink signal-to-interfernce-plus-noise-ratio (SINR) coverage probability, rate coverage probability and area spectral efficiency (ASE) of millimeter wave cellular network. The locations of base stations (BSs) and the user equipments (UEs) are modeled as two independent homogeneous Poisson Point Process

Integration of Device-to-Device communication in 5G Heterogeneous networks (HetNets) promises to increase resource utilization and spectrum efficiency (SE). However, the broadcast nature of wireless communication makes it vulnerable to an eavesdropper, who can steal useful information from the transmission channel. Hence, ensuring secure communication for both cellular users (CUs) and D2D pairs is

Filter bank multicarrier (FBMC) techniques are emerging alternatives to the widely used orthogonal frequency division multiplexing (OFDM) schemes for applications such as machine type communications or cognitive radio. Recently an FBMC scheme based on a sine prototype filter with overlapping factor K=2 termed FBMC-PAM has been introduced. It assures an interesting performance, a reduced system latency

Signal automatic modulation classification refers to modulation methods which can automatically classify and identify different communication signals. As the middle part of the signal detection and demodulation, modulation classification plays an important part in the area of military and civilian fields, such as software radio and electronic countermeasures. In recent years, modulation classification

In this paper, we analyze the secrecy outage performance for an unmanned aerial vehicle (UAV) -enabled relaying non-orthogonal multiple access (NOMA) system, in which a source transmits a superimposed signal under the NOMA protocol to two users via a UAV-enabled decode-and-forward relay in the presence of an eavesdropper. Assuming the channels experience Nakagami-m fading and both hops are wiretapped

Mission-critical communication (MCC) is one of the main goals in 5G, which can leverage multiple device-to-device (D2D) connections to enhance reliability for mission-critical communication. In MCC, D2D users can reuses the non-orthogonal wireless resources of cellular users without a base station (BS). Meanwhile, the D2D users will generate co-channel interference to cellular users and hence affect

Under the condition of non-cooperative wireless communication, many signals always overlap in time–frequencyfield, therefore, the signal separation and reconstruction of the received mixed signals is of great significance for the subsequent information processing. A new blind separation strategy is proposed to solve the blind separation problem in non-cooperative communication under general underdetermined

Precise and agile pointing performance based on the fusion or combination of its on-board sensor inputs such as gyroscope and star-tracker are critical in spacecraft platform. This is very critical in keeping the accuracy of the satellite platform orientation when performing task requests from the earth control station. However, the processing speed greatly depends on the satellite attitude. Attitude

In this paper, a multiple-input single-output (MISO) full-duplex two-way cooperative non-orthogonal multiple access (NOMA) system is considered. The relay is energy-restricted and may not accomplish the information exchange between two end users. To address this problem, simultaneous wireless information and power transfer (SWIPT) is proposed, which employs power splitting (PS) at the relay to harvest

Physical layer security protects the transmitted data by trying to prevent the information from reaching the adversary. Adding artificial noise (AN) to the transmitted data helps to achieve that goal. In this paper, AN technique is used to protect the transmission of the secondary user (SU) from an eavesdropping attack in an energy harvesting cognitive radio network with hybrid channel access. At the

As one of the promising technologies, non-orthogonal multiple access (NOMA) provides high system capacity, low latency, and massive connectivity. NOMA is expected to address several challenges in the fifth-generation (5G) and beyond wireless systems. In this paper, we consider the downlink Internet of Things (IoT) system with grouping user-relying NOMA techniques to improve the performance of the cell-edge

In this paper, we investigate a cooperative Internet of Things (IoT) communication network with decode-and-forward relay nodes that can be eavesdropped, where the relay node harvests energy from the received signal power to charge its battery, which is used to retransmit the received signal to the destination. The secrecy communication of the energy harvesting Gaussian eavesdropping channel has been

Self-adaptive threshold adjustment algorithms (SATAs) are required to reconfigure their parameters autonomously (i.e. to achieve self-parameter adjustment) at runtime and during online use for effective signal detection in cognitive radio (CR) applications. In this regard, a CR system embedded with the functionality of a SATA is termed a self-reconfigurable CR system. However, SATAs are challenging

This paper investigates an unmanned aerial vehicle (UAV)-enabled wireless power transfer (WPT) system, where a UAV acts as the energy transmitter (ET) to deliver radio frequency (RF) energy to a set of energy receivers (ERs). Our aim is to maximize the total harvested energy at all ERs by jointly optimizing the three-dimensional (3D) position of the UAV and beam pattern. However, the optimization problem

In Content-Centric network (CCN), the capacity of router nodes caches the contents to satisfy the requests from subsequent consumers, and reduce the network overhead. Considering the limited cache capacity, the update of cached contents becomes a key element affecting the caching performance for the future 6G network. In this paper, a replacement strategy based content popularity and cache gain (PGR)

Wideband and agile Spectrum Estimation (SE) is a fundamental component of the Cognitive Radio (CR) system. However, CR systems generally utilize the classical sensing techniques for SE due to heteroscedasticity of the available spectrum. Unfortunately, analysis of the Time-series data for SE using a testbed is rare to find out. A novel Goodness-of-Fit (GoF) based accurate SE technique for CR system

In this paper, an intelligent electromagnetic environment reconstruction method is proposed based on a super-resolution generative adversarial network (SRGAN). The altitude matrices together with the low-resolution matrices obtained by measured power values are employed as inputs. Then, an electromagnetic environment reconstruction method capable of generating the high-resolution power coverage matrix

The excellent features of the sixth generation (6G) of wireless technology enthuses researchers to apply advanced and complex techniques on mobile communication networks, which is what this paper explores. As a result of the ability of 6G to exchange vast data rates and network programming, the Cooperative Network Coding (CoNC) technique can be implemented to improve the connectivity and diversity

Making phone calls, sending messages and surfing the Internet all depend on wireless communication. Too many users connect to a same base station at the same time, which would slow network speed down. To address this issue, telecom operators can tune the network capacity in advance according to predicted Maximum Connections. Therefore, predicting Maximum Connections is necessary. Traditional time series

The intelligent reflecting surface (IRS) consist of multiple passive elements which make it can passively reflect signals by setting phase angles. The design of IRS has been widely discussed due to its low power consumption and low-cost in recent years. In this article, IRS is used to improve the performance in a secrecy communication system which compose of multiple eavesdroppers equipped with multiple

Zigbee is a popular communication protocol in the Internet of things (IoT) which shows great potential in smart home. However, the smart device has the risk of being hijacked by unauthorized users and may result in privacy disclosure. Traditional device identification is based on cryptography which is easy to be cracked. Recently, radio frequency fingerprinting identification (RFFID) is popular in

In this paper, a channel estimation method based on reduced dimension decomposition for millimeter-wave massive MIMO systems is proposed. For the sake of obtaining the high accuracy of the estimation, we decompose the channel matrix estimation into angle information and channel gain information estimation. The received signals are decomposed by dimensionality reduction so that the angles of the receiving

In practical engineering, the communication networks of industrial systems are complex, and system models are generally unavailable. To overcome the requirement of mathematical models, several artificial-intelligence-based algorithms in multi-access edge computing are introduced for the performance optimization control of a benchmark microgrid in this paper. First, a neural-network-based identification

In this paper, soft-decision (SD) decoders of permutation trellis code (PTC) with M-ary frequency shift keying are designed using three optimization algorithms and presented in four decoding schemes. In a concatenated code such as PTC, the Viterbi decoder for the outer convolutional code provides maximum likelihood decoding. Hence, the error correction performance is dependent on the decoding scheme

Direction-of-arrival (DOA) estimation is essential for wireless communications, especially in the recent developed artificial intelligence (AI)-based approaches. In this paper, we investigate into the problem two-dimensional (2D) DOA using electromagnetic vector sensors (EMVS) array, and a covariance tensor-based estimator is introduced. Firstly, the array covariance matrix is formulated into a fourth-order

Energy consumption has become a crucial problem in the design of vehicle routing problems, hence the need to use another delivery method powered by batteries. Unmanned aerial vehicles have become fundamental tools in tasks for which man has limited skills that prevent a superlative optimization of time. The increasing use of drones by commercial companies such as Amazon, Google, and DHL has given birth

A wireless communication system using Chirp Spread Spectrum Modulation (CSSM) is analyzed in this study while assuming mobile nodes. CSSM exhibits promising error performance under very low signal-to-noise ratio values. Thereby, CSSM has been adopted in systems that generate low data traffic over long distances, such as low-power wireless networks. Existing studies reveal the significant advantages

Non-orthogonal multiple access (NOMA) is one of the key potential technologies for beyond 5G, i.e., 6G, networks. However, power allocation for spectral efficiency (SE) and energy efficiency (EE) tradeoff for uplink NOMA systems is still an open problem. In this study, we investigate the power allocation problem to maximize SE–EE tradeoff for systems with multi-cluster multi-user applications. Firstly

In fifth-generation (5G) wireless communication systems, non-orthogonal multiple access (NOMA) has been considered as a promising multiple access technique. In this paper, a NOMA-based cooperative relay system (CRS) is proposed and analyzed. In contrast to the conventional cooperative relay NOMA system (system model in Kim and Lee (2015)), the proposed NOMA-based CRS allows a source and a relay to

One of the main barriers in front of Free Space Optical (FSO) communication systems is the atmospheric turbulence induced fading. Theoretically, the Maximum Likelihood (ML) detector is the optimum detector. The ML detector requires Channel State Information (CSI), which can be provided in perfect or blind forms. The perfect CSI ML detector requires pilot transmission for channel estimation, which increases

To meet the growing demand for indoor wireless positioning in B5G environment, a high-precision indoor positioning system is designed in this paper. The designed system adopts the fusion of multi-source positioning techniques, to chieve the reasonable cost and reliability. First, Considering the B5G environment, a two-steps fusion algorithm is proposed for the designed system, in which the UWB and

In wireless sensor network, robustness is one of the basic network performances, which influences the network lifetime. At the same time, because of the bad environment, the comprehensive failure probability is increased and the cascading failure is caused, which reduces the network robustness. To solve the problem, a failure probability of nodes is described by constructing a model of comprehensive

Cubic metric (CM) is a more precise measure to compute the large envelope fluctuations of orthogonal frequency division multiplexing signals. In this study, we use the partial transmit sequence method to reduce the high CM of signals. Despite the dramatic CM reduction ability of the partial transmit sequence method, its computational complexity is very high because of an exhaustive search over all

The peak-to-average power ratio (PAPR) is one of the most serious issues to be dwelled on, carefully, in wireless communication. It is not possible to take the advantage of multicarrier transmission strategy without handling the problem of high PAPR arising from the usage of multiple subcarriers for generating the time domain transmission signals. As being a kind of multicarrier waveform, universal

In this paper, beamforming for device-to-device multicast communication under channel uncertainty arising from incomplete channel state information is considered. The problem is first formulated as a non-robust minimization problem subject to signal-to-interference-plus-noise ratio, transmit power and interference constraints. Using semi-definite programming relaxation, a tractable convex robust counterpart

Cognitive Radio (CR) and Cooperative Communication provide key technologies for efficient utilization of available unused spectrum bands (called resources) to achieve a spectral efficient system with high throughput. But to achieve its full potential, it is essential to empower the brain of CR that is Cognitive Engine (CE), using machine learning algorithms to control the operation and adapt parameters

In this paper, we investigate a secure cognitive radio network (CRN), which deploys non-orthogonal multiple access (NOMA) to deliver a mixed multicast and unicast traffic to the intended receivers, while keeping them secret from the eavesdroppers. This model represents a cognitive interference channel with an external eavesdropper (CIC-EE). In this model, there are one pair of primary nodes, one pair

Frequency spreading filter bank multicarrier (FS-FBMC) is widely considered as a potential candidate for the air interface of the next-generation mobile communication, 5G. The prototype filter plays a pivot role in the frequency–time confinements to obtain a better performance, as a result of mitigating the inter-carrier interference and the inter-symbol interference. In this work, the architecture

Emerging communication systems can benefit from time-reversal (TR) technology thanks to its good spatio-temporal signal focusing effect. The recent advances in low-cost wideband devices fabrication further leverage the use of TR wideband communication systems. The TR is generally carried out in the time domain and the focusing effect of TR comes from the use of a high transmit rate back-off factor

In this paper, we introduce a novel modulation recognition method of digital communication signals with alpha-stable noise to solve the problem of low recognition performance in mixed signal-to-noise-ratio environment. The received signals are separated into signals and alpha-stable noise by employing fractional lower order fast independent component analysis (FLO-Fast-ICA), and then the separated

To meet the anticipated challenges of the fifth-generation and beyond wireless networks, multiple candidate technologies are needed to be integrated. Motivating by this, two cooperative simultaneous wireless information and power transfer (SWIPT) protocols are proposed in this study for cellular internet of things (IoT) networks by exploiting non-orthogonal multiple access considering two different

As the radio spectrum becomes increasingly crowded, the superior spectral capacity in the visible light range becomes increasingly attractive. Visible light communication (VLC) technology uses the light waves from light emitting diode (LED) lamps and overheads to stream data and connect people as a more efficient, more available, and more secure alternative to Wireless Fidelity (Wi-Fi). The aim of

This paper deals with the problem of device’s location using Wi-Fi signal strength in an indoor environment. In order to improve the location accuracy a new fingerprinting-probabilistic algorithm is proposed. In this algorithm, the probability distribution of the Received Signal Strength (RSS) by a Mobile User (MU) from several Access Points (AP) is approximated using the Gaussian Mixture Model (GMM)

The ordered statistics (OS) scheme is an effective constant false alarm rate (CFAR) technique deployed in many radar systems. It is widely deployed because of its simplicity and effectiveness under conditions of both homogeneous and non-homogeneous radar returns. However, the problem of inaccurate censoring typically degrades its performance since it is often difficult to accurately determine the actual

In this paper, we propose a secure hybrid pulse compression method for radar waveform design. This method uses a confidential code as the phase-code for the binary-shift keying modulation. We also use another confidential code for the frequency-code. This code is replaced in the frequency control register of a direct digital synthesizer to perform the narrow-band frequency-shift keying. We exploit

Automatic modulation classification (AMC) is a critical step to recognize the unknown signal modulation types. It is widely applied in non-cooperative communication systems with diverse modulation types and complex communication environments. In recent years, existing deep learning based AMC methods have been developed to improve the performance of classification in additive white Gaussian noise (AWGN)

In vehicle-to-network (V2N) communication, it is a great challenge to remain the communication performance of vehicles at all times in case of the mobility of vehicles. This paper investigates a novel architecture of unmanned aerial vehicle (UAV)-assisted V2N communication, where UAV with caching serves as a carrier of flying base station to jointly communicate with vehicles. The optimization problem

This paper presents a novel nature inspired dragonfly based, optimization paradigm, named as dragonfly search convergence and coverage algorithm (DSCCA) for resource allocation in an industrial wireless network. This paradigm imitates the swarming behavior of the dragonfly for optimized and efficient resource allocation to fulfill multi-objective of better throughput, low error probability, and low

This paper addresses turbo codes with component convolutional codes as those in the Long Term Evolution (LTE) standard. We consider the interleaver lengths of the form L=32kLΨ, with kL∈{1,3} and Ψ is a product of prime numbers greater than three. For these interleaver lengths, we have shown that a true cubic permutation polynomial (CPP) f1x+f2x2+f3x3(modL), under the constraint f3=0(modpi) when a prime

The wide application of contour stellar images has helped researchers transform signal classification problems into image classification problems to solve signal recognition based on deep learning. However, deep neural networks (DNN) are quite vulnerable to adversarial examples, thus simply evaluating the adversarial attack performance on the signal sequence recognition model cannot meet the current

To detect and estimate the faults of discrete linear time-varying uncertain systems, a discrete learning strategy is applied to fault diagnosis, and a new fault-detection and estimation algorithm is proposed. The algorithm adopts the threshold-limit technology. In the selected optimal time domain, a residual signal is used to perform iterative learning correction for the introduced virtual faults so

A subset of the synchronization algorithms in a wireless receiver are responsible for tracking the phase and frequency of a digitally modulated signal. If variations of the phase in the signal are substantial, then the receiver might be unable to track them leading to inability to demodulate the data. In this paper we propose a method for improving the secrecy of wireless communication by ensuring

To cope up with drastically increasing demand for radio resources lead to raise a challenge to the wireless community. The limited radio spectrum and fixed spectrum allocation strategy have become a bottleneck for various wireless communication. Cognitive Radio (CR) technology along with potential benefits of machine learning has attracted substantial research interest especially in the context of

In this paper, we introduce new totally blind spectrum sensing (SS) algorithms, for fast time-varying channel, based on eigenvalue decomposition (EVD) of the covariance matrix of the received signal. The new scheme is based on the sliding window whose the size depends on the coherence time of the channel. First, we evaluate the impact of the mobility on the detection performance. Then, by applying

The process of joint user and receive antenna scheduling is very vital in the uplink direction of multi-antenna wireless data communications system with multiple users. With higher number of receive antennas and active users, the search space becomes huge for the joint user and receive antenna scheduling process. It is very difficult to accomplish the searching through the entire search space within

This article presents a novel flexible wideband ink-printed dipole array antenna for emerging medical sensing and human body wearable electronics applications. The antenna operates from 23 GHz to 30 GHz, including 24.5 GHz and 28 GHz for 5G application. The antenna consists of simple layered screen printed structure, which is suitable for rapid prototyping with printing technology. Both simulation

Massive multiple-input-multiple-output (M-MIMO) is a key technology for 5G networks. Within this research area, new types of deployment are arising, such as the extremely-large regime (XL-MIMO), where the antenna array at the base station (BS) has extreme dimensions. As a consequence, spatial non-stationary properties appear as the users see only a portion of the antenna array, which is called visibility

Non-Orthogonal Multiple Access (NOMA) has been a hot research topic over the past years, because it is widely viewed as a promising technology for 5G cellular networks and beyond. The NOMA literature today is heavily based on the so-called Power-Domain NOMA (PD-NOMA), which consists of superposing user signals with different powers. Also, the focus in the literature has been on the derivation of achievable