Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

In this letter, we propose a deep learning-based spreading sequence design and active user detection (AUD) to support massive machine-type communications (mMTC) where a large number of devices access the base station using non-orthogonal spreading sequences. To design the whole communications system minimizing AUD error, we employ an end-to-end deep neural network (DNN) where the spreading network

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

In this letter, a performance study of a mixed dual-hop communication system consisting of free-space optical/underwater wireless optical communication (FSO-UWOC) links is presented. In particular, considering both heterodyne detection and intensity modulation with direct detection (IM/DD), we assume that the FSO channel suffers a Gamma-Gamma fading in the presence of pointing error impairments, while

Deep learning (DL) has been gradually applied to wireless communication and has achieved remarkable results. However, training a DL model requires numerous data, and an insufficient training dataset will cause serious overfitting problem and reduce model accuracy. Data augmentation (DA) is one of the commonly used techniques to solve the above problem. It is widely used to improve the performance of

This letter investigates the finite blocklength covert communications where transmitter Alice randomly chooses channel use according to probability $\rho $ in the transmission block. To minimize the decoding error probability of a receiver Bob subject to the covert constraint on a detector Willie, we consider a new scheme that is changing the selection probability $\rho $ . A proof is given for the

To reduce the large training overhead required by a millimeter-wave (mmWave) massive MIMO system, this letter proposes a pilot placement scheme and the corresponding receiver technique for multi-user uplink channel estimation and data detection over frequency-selective fading channels when OFDM is employed. Specifically, a small group of subcarriers transmit a small segment of pilots followed by data

Channel estimation is challenging for the reconfigurable intelligence surface (RIS) assisted millimeter wave (mmWave) communications. Since the number of coefficients of the cascaded channels in such systems is closely dependent on the product of the number of base station antennas and the number of RIS elements, the pilot overhead would be prohibitively high. We propose a cascaded channel estimation

We investigate the impact of fading correlation on the performance of the doubly dirty fading multiple access channel (MAC) with non-causally known side information at transmitters. Using Copula theory, we derive closed-form expressions for the outage probability (OP) and the coverage region under positive/negative dependence conditions. We show that a positive dependence structure between the fading

The 4G and 5G deployment of massive MIMO capable radios increase peak EIRPs, which in turn increase the sizes of the RF EMF exclusion zones applied for the general public and workers if time averaging is not considered, sometimes to dimensions exceeding 20 meters. The deployment becomes even more challenging when multiple massive MIMO transmitters are co-sited with overlapping antenna ranges. This

Intelligent reflecting surface (IRS) has recently emerged as a new solution to enhance wireless communication performance via passive signal reflection. In this letter, we unlock the potential of IRS controller in relaying information and propose a novel IRS-assisted communication system with both IRS passive reflection and active relaying. Specifically, we jointly optimize the time allocations for

Channel modeling is a critical issue when designing or evaluating the performance of reconfigurable intelligent surface (RIS)-assisted communications. Inspired by the promising potential of learning-based methods for characterizing the radio environment, we present a general approach to model the RIS end-to-end equivalent channel using the unsupervised expectation-maximization (EM) learning algorithm

In Radio Frequency Identification (RFID) applications, multiple tags may be deployed on the same object or area for security or precision purposes. These tags carry similar information and so can be grouped into a category. To collect such information, most existing works have to query all tags in each category, which is time-consuming. However, sampling a subset of tags from each category is sufficient

A novel status update information system is designed by jointly considering wireless energy harvesting diversity, status update transmission diversity, and hybrid automatic repeat request with chase combining (HARQ-CC) diversity, which consists of two sensors and one destination. The two sensors, which have finite-sized batteries, harvest energy from a Bernoulli process, and cooperatively deliver the

In isolated regions, utilizing the unmanned aerial vehicle (UAV) as an aerial anchor node is a promising technique to enable location awareness of ground terminals (GTs). In this letter, considering a UAV swarm-enabled localization for a group of distributed GTs, we aim to minimize the maximum Cramer-Rao lower bound (CRLB) for position estimates with anchor uncertainty. Then, an efficient differential

In this letter, a new method on the ${K}$ -factor estimation is proposed for wireless communications over Rician frequency-flat fading channels. Firstly, the mean and variance of the squared envelope of the received signal are respectively derived. Then, we employ them to further derive the closed-form expression for the ${K}$ -factor and finally present its estimation formula. Performance analyses

In this letter, we consider a problem of throughput optimum channel switching for channel access by a secondary user in multichannel Cognitive Radio Networks in which there is a delay involved in switching from one channel to another. We consider an imperfect sensing model that takes into account false alarm and detection probabilities. We show that the problem can be posed in the framework of Partially

Accurate and convenient energy consumption models (ECMs) for rotary-wing unmanned aerial vehicles (UAVs) are important for UAV communication designs. Existing models are complex and inconvenient to use. In this letter, a simple and easy-to-use model with closed-form expression as a function of the initial velocity, acceleration and time duration is derived. Using this model, the UAV flight control

Beamforming technology is widely used in millimeter wave systems to combat path losses, and beamformers are usually selected from a predefined codebook. Unfortunately, the traditional codebook design neglects the beam squint effect, and this will cause severe performance degradation when the bandwidth is large. In this letter, we consider that a codebook with fixed size is adopted in the wideband beamforming

Two-path successive relaying (TPSR) systems have been recently proposed as powerful candidates for improving the spectral efficiency of cooperative communications. The previously reported investigations for such systems are limited to information-theoretic analysis, parameters estimation, interference cancellation, and data detection. In this contribution, we discuss the problem of modulation classification

A key issue in the two-path successive relaying (TPSR) communications systems is the interference, which is caused by the concurrent transmission of the source and one of two relays. The previously reported investigations show that interference cancellation is required at the relays and destination to avoid severe performance degradation. In this work, we introduce a different approach that does not

Non-orthogonal multiple access (NOMA) has a larger achievable sum rate than orthogonal multiple access (OMA). This superiority is achieved via superposition coding (SC) and successive interference cancellation (SIC). In this letter, the authors propose a lossless NOMA implementation without SIC. This implementation is achieved via correlated SC (CSC), in contrast to conventional independent SC (ISC)

In this letter, we consider outer-loop link adaptation, wherein we pursue to find the optimum modulation and coding scheme (MCS) that provides the maximum throughput without directly estimating the channel state. We cast this problem in a form of multi-armed bandit, an online decision making policy based on sequential observations. To efficiently solve a formulated problem, we propose a novel two-stage

The recently developed orthogonal time frequency space (OTFS) modulation has shown its capability of coping with the fast time-varying channels in high-mobility environments. In particular, OTFS modulation gives rise to the sparse representation of the delay-Doppler (DD) domain channel model. Hence, one can an enjoy accurate channel estimation by adopting only one pilot symbol. However, conventional

In this letter, we consider a wireless uplink transmission scenario in which an unmanned aerial vehicle (UAV) serves as an aerial base station collecting data from ground users. To optimize the expected sum uplink transmit rate without any prior knowledge of ground users (e.g., locations, channel state information and transmit power), the trajectory planning problem is optimized via the quantum-inspired

Underwater wireless optical communication (UWOC) has been proposed to provide high-rate data services by exploiting the ample optical spectra. However, the underwater scenario presents a hostile environment for wireless optical signal propagation due to the various channel effects, such as absorption, scattering and turbulence. Furthermore, link misalignment (LM) between the optical transmitter and

In this letter, we propose three schemes designed to detect attacks over the air interface in cellular networks. These decision rules rely on the generalized likelihood ratio test, and are fed by data that can be acquired using common off-the-shelf receivers. In addition to more classical (barrage/smart) noise jamming attacks, we further assess the capability of the proposed schemes to detect the stealthy

With the increasing adoption of fifth-generation (5G) networks and wide bandwidth availability, unmanned aerial vehicles (UAVs) should now be practicable to stream and operate at different altitudes and upload incredibly large quantities of data from sensors. We develop a novel intelligent sensing framework (Choi, 2020) so that sensing and communication occur on demand, according to a given query.

Free space optical (FSO) communication systems experience turbulence-induced fading. As a possible solution to mitigate the effects of fading, adaptive transmission that allows the adjustment of transmission parameters such as transmit power and modulation size can be used. Most of the existing works on adaptive FSO systems assume the presence of full channel state information (CSI) at the transmitter

Perfect channel state information (CSI) is usually required when considering relay selection and power allocation in cooperative communication. However, it is difficult to get an accurate CSI in practical situations. In this letter, we study the outage probability minimizing problem based on optimizing relay selection and transmission power. We propose a prioritized experience replay aided deep deterministic

A new approach based on deep learning techniques for multidimensional codebook (MDC) design over Rayleigh fading channels is proposed in this letter. Different from autoencoder (AE) techniques, the proposed deep neural network (DNN) can generate codebooks directly without a decoder structure. Two loss functions, one exploiting essential figures of merit (FoMs) and the other based on theoretical symbol

The time-varying deviations of the phase shifter network (PSN) may cause significant performance degradation in the millimeter-wave (mmWave) multiuser communication system, especially when serving fast-moving users. In this letter, we propose an efficient joint real-time phase shifter network calibration and beam tracking (JRTPSNC-BT) algorithm. In each tracking period, the exploration strategy is

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

The high reflect beamforming gain of the intelligent reflecting surface (IRS) makes it appealing not only for wireless information transmission but also for wireless power transfer. In this letter, we consider an IRS-assisted wireless powered communication network, where a base station (BS) transmits energy to multiple users grouped into multiple clusters in the downlink, and the clustered users transmit

In this letter, a received signal strength difference (RSSD) approach is presented to localize a source with unknown transmit power in the presence of sensor position errors. The performance of conventional least squares (LS) algorithms is degraded because they consider measurement errors rather than estimation errors. An algorithm is presented here to overcome this problem. First, a robust minimax

In this letter, we investigate joint application of intelligent reflecting surface (IRS) and vertical beamforming in cognitive radio networks (CRN). After properly modeling the network, an optimization problem is formed to jointly design the beamforming vector and tilt angle at the secondary base station (BS) as well as the phase shifts at the IRS with the objective of maximizing spectral efficiency

We propose an algorithm for decentralized optimization in wireless device-to-device (D2D) networks of pervasive devices such as sensors or 5G handsets, in which the signs of stochastic gradient are used for descent steps. Our algorithm has the convergence rate of ${O}$ (1/( nT )) in which ${n}$ is the number of devices and ${T}$ is the number of learning iterations, saving the communication efficiency

Positioning services in cellular networks are at risk of being abused by unauthorized users, which may severely damage the interests of operators and legitimate users. In this letter, multiple unmanned aerial vehicles (UAVs) are employed as mobile jammers to disrupt the positioning services at unauthorized users, thereby enhancing the controllability of services at the physical layer. Specifically

A cell-free Massive multiple-input multiple-output (MIMO) system is considered, where the access points (APs) are linked to a central processing unit (CPU) via the limited-capacity fronthaul links. It is assumed that only the quantized version of the weighted signals are available at the CPU. The achievable rate of a limited fronthaul cell-free massive MIMO with local minimum mean square error (MMSE)

This letter provides a theoretical analysis of the radio signal energy harvested from wireless mobile nodes. A nonlinear energy harvesting model based on the research results is proposed. This model is practical but tractable through stochastic geometry. A Gauss-Markov model is used as a mobility model, one that is versatile and can cover various mobile scenarios. The closed form formulas of the first

Intelligent reflecting surfaces (IRSs) can be beneficial to both information and energy transfer, due to the gains achieved by their multiple elements. In this work, we deal with the impact of spatial correlation between the IRS elements, in the context of simultaneous wireless information and power transfer. The performance is evaluated in terms of the average harvested energy and the outage probability

The advantages of massive multiple-input multiple-output (MIMO) techniques depend heavily on the accuracy of channel state information (CSI). In frequency division duplexing (FDD) massive MIMO systems, the user equipment (UE) needs to feed downlink CSI back to the base station (BS) through the feedback link. The excessive feedback overheads and low reconstruction accuracy are the main obstacles for

This letter studies a delay-optimal multi-destination computation offloading system, where the subtasks are transmitted to multiple Edge Computing Servers (ECSs) sequentially due to the limited communication resource, and different subtasks are computed in parallel at different ECSs. Consider the communication and computation capabilities, we jointly optimize the task assignment and the offloading

In reconfigurable intelligent surfaces (RISs) aided communications, the existing passive beamforming (PB) design involves polynomial complexity in the number of reflecting elements, and thus is difficult to implement due to a massive number of reflecting elements. To overcome this difficulty, we propose a reflection-angle-based cascaded channel model by adopting the generalized Snell’s law, in which

In the present letter, a closed-form framework is derived for the system-level modelling, analysis and optimization of the energy efficiency (EE) in LoRa networks. The proposed framework is derived by exploiting stochastic geometry tools and associates the Long Range (LoRa) EE with the density of end-devices (EDs) and the ED transmit power. The analysis reveals the trends of the EE curve with respect

This letter presents a new scheme to solve the issue of high redundant energy in Unique Word Orthogonal Frequency Division Multiplexing (UW-OFDM). The proposed scheme, called Low-Redundant Energy UW-OFDM (LRE-UW-OFDM), is suitable for time-varied harsh channels such as the Underwater Acoustic (UWA) channel were inserting the UW data in the time domain leads to huge redundant energy and a dramatic deterioration

In this letter, we develop a new framework to jointly characterize covertness and timeliness of short-packet communications, in which a new metric named covert age of information (CAoI) is first proposed and then a closed-form expression for the average CAoI is derived. Our examination explicitly reveals the tradeoff between communication covertness and timeliness affected by the block-length, transmit

A new approach to estimate the direction-of-arrival (DOA) in a Time-Modulated Array (TMA) system with a bipolar squared periodic time-modulating sequence is proposed in this letter. Using such a sequence can increase the power of harmonic components of the received signal. Based on this fact, we formulated a new parameter pertaining to the ratio of the upper and lower sideband first harmonic components

This letter investigates the downlink integrated low earth orbit (LEO) satellite-terrestrial millimeter-wave decode-and-forward relay network, where the satellite and terrestrial relays locate in uniform distribution over the spherical cap surface of the LEO and in Poisson point process over the ground, respectively. In order to obtain fine-grained information on the coverage performance, the meta

This letter investigates the localization problem with distance-dependent noise and sensor location uncertainty. The formulated localization problem is very challenging and non-convex due to the coupled distance-dependent noise variance and the location uncertainty, as well as the nonlinearity in the distance function. A low complexity two-step algorithm that incorporates maximum likelihood and Gaussian

Code-expanded Random Access (CeRA) is a promising technique for supporting massive machine-type communications in cellular IoT networks. However, its potentiality is limited by code ambiguity, which results from the inference of a larger number of codewords than those actually transmitted. In this letter, we propose a random access (RA) scheme to alleviate this problem by allowing devices to select

There is illegitimate transmission of information between suspicious users, whereas single legitimate monitor (LM) has finite capacity to satisfy eavesdropping. This letter studies a cooperative proactive eavesdropping(CPE) scheme, where two LMs eavesdrop on multiple suspicious links simultaneously with a cooperative jamming method under finite power constraint. Specifically, two LMs collaborate to

This letter presents a novel iterative positioning method for tracing the body segments of a person moving indoors using radio-frequency (RF) signals. The indoor space is equipped with a multiple-input multiple-output (MIMO) communication system. The person is modelled by a cluster of moving point scatterers, playing the role of moving body segments. The proposed technique estimates the time-variant

Physical layer secret key generation is a promising candidate to achieve one-time-pad encryption approach for the wireless communication system. However, in a static environment, the secret key rate is low due to the lack of channel time-variation. To solve this problem, this letter proposes a novel secret key generation scheme assisted by an intelligent reflecting surface with discrete phase shifts