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.

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 introduce direct-current (DC) offset hybrid frequency and phase-shift keying (DC-FPSK) modulation for Internet-of-Things based on optical wireless systems. For DC-FPSK, non-negative phase-modulated frequency waveforms are generated by combining frequency-shift keying (FSK), phase-shift keying (PSK) and a DC offset. We propose optimal maximum likelihood and sub-optimal receivers for

For reentry communication, owing to the influence of the time-varying plasma sheath, the received IQ baseband signals are severely rotated on constellation. Researches have shown that the frequency of electron density varies from 20kHz to 100 kHz which is on the same order as the symbol rate of most TT&C communication systems and traditional estimation algorithms cannot track the variation of channel

This letter is on the multi-user massive multi-input multi-output (MIMO) uplink with the mixed analog-to-digital converter (ADC) architecture and the zero-forcing (ZF) receiver at the base station (BS). Under imperfect channel state information (CSI), a closed-form approximation of the spectral efficiency (SE) is derived for a general resolution profile. Further, simplified SE results are provided

This letter investigates hybrid networks composed of a radio frequency (RF) access point (AP) and multiple visible light communication (VLC) APs. We consider mobile multi-homing users that can aggregate resources from both RF and VLC APs. In hybrid RF/VLC networks, RF channel gains vary faster than VLC channels due to small scale fading. By leveraging multi-agent Q-learning to interact with the dynamics

Predictor antenna (PA) system is referred to as a system with two sets of antennas on the roof of a vehicle, where the PAs positioned in the front of the vehicle are used to predict the channel state observed by the receive antennas (RAs) that are aligned behind the PAs. This letter studies the performance of PA systems in the presence of the mismatching problem, i.e., when the channel observed by

Multiple-input multiple-output (MIMO) visible light communication (VLC) systems can support high data rates for indoor communications. In this letter, we focus on maximizing the energy efficiency (EE) of MIMO VLC systems, where the non-negativeness of the transmit signal, the optical and electrical power constraints, and the data rate and bit error rate (BER) requirements are taken into account. The

In pursuance to understand the behavior of a potential green hybrid attacker in secure Internet-of-Things (IoT), this letter investigates optimal energy utilization from the attacker’s viewpoint. Specifically, we propose a novel framework for optimizing the efficacy of a hybrid attacker, possessing capability to both eavesdrop and jam, while considering the underlying energy consumption. In particular

In cloud radio access network (Cloud-RAN), dense remote radio heads (RRHs) connect to baseband unit (BBU) pool through optical transport link, causing significant interference and power consumption in multicast downlinks. Coordinated beamforming with RRHs clustering is expected to be a key element towards improving network performance with more consideration of energy efficiency and interference management

This letter presents a new downlink cooperative non-orthogonal multiple access (NOMA) transmission scheme to serve three users within only two time slots. The scheme involves a base station (BS), two direct-link users and one indirect-link user. The BS sends superposed signals to the two direct-link users which decode and forward the signals to the indirect-link user in an alternating fashion. Closed-form

The extremely diverse service requirements is an important challenge for the future generations of wireless communication technologies. As promising solutions, orthogonal frequency division multiplexing (OFDM)-based massive multiple-input multiple-output (MIMO) and mixed numerologies transmission are proposed. This letter investigates the transmission of different users, sharing the same bandwidth

This letter investigates full-duplex unmanned aerial vehicle (UAV) aided small cell wireless systems, where the UAV serving as the base station (BS) is designed to transmit data to the downlink users and receive data from the uplink users simultaneously. To maximize the total system capacity, including uplink and downlink capacity, the UAV trajectory, downlink/uplink user scheduling, and uplink user

This letter proposes a low-latency secure mobile edge computing (MEC) system where multiple users offload computing tasks to a base station in the presence of an eavesdropper. We jointly optimize the users’ transmit power, computing capacity allocation, and user association to minimize the computing and transmission latencies over all users subject to security and computing resource constraints. Numerical

The rapid expansion of Machine Type Communication (MTC) has brought many challenges, such as sporadic uplink transmission congestion and energy consumption of battery limited nodes. To address these challenges, we consider a green energy harvesting massive MTC (mMTC) system that each device is equipped with a local cache and a rechargeable battery to store the collecting data and the green energy harvested

In this letter, we study a wireless communication system with a fixed-wing unmanned aerial vehicle (UAV) employed to collect information from a group of ground nodes (GNs). Our objective is to maximize the UAV’s energy efficiency (EE), which is defined as the achievable throughput among all GNs per unit propulsion energy consumption of the UAV. To efficiently solve this problem with continuous-time

In three-dimensional (3D) vehicular ad-hoc network (VANET) scenario, dynamic vehicles, complex node distribution and severe path loss increase the probability of link interruption significantly, which deteriorates the packet reception probability sharply. However, reliability is a crucial issue as efficiency to improve the performance of routing protocol in 3D VANET. In this letter, for the dynamic

In this letter, we study federated learning in a cellular system with a base station (BS) and a large number of users with local data sets. We show that multichannel random access can provide a better performance than sequential polling when some users are unable to compute local updates (due to other tasks) or in dormant state. In addition, for better aggregation in federated learning, the access

The use of massive multiple-input multiple-output (MIMO) to serve a crowd of user equipments (UEs) is challenged by the deficit of pilots. Assuming that the UEs are intermittently active, this problem can be addressed by a shared access to the pilots and a suitable random access (RA) protocol. The strongest-user collision resolution (SUCRe) is a previously proposed RA protocol that often privileges

In this letter, we investigated the achievable spectral efficiency and complexity of a single-user millimeter wave massive multiple-input-multiple-output system with hybrid analog/digital transceiver architecture. We then proposed a new low-complexity alternating minimization algorithm based on the Barzilai-Borwein gradient algorithm to maximize the spectral efficiency. Accordingly, in order to minimize

Cognitive radio networks (CRNs) are considered a promising solution for spectrum resources scarcity and efficient channel utilization. In this letter, multi-dimensional analytical Markov model based on reservation channel access scheme and channel aggregation method is proposed to enhance spectrum utilization, capacity of low priority secondary users (SUs) and reducing handoff probability of SUs. Moreover

In the intelligent reflecting surface (IRS)-enhanced wireless communication system, channel state information (CSI) is of paramount importance for achieving the passive beamforming gain of IRS, which, however, is a practically challenging task due to its massive number of passive elements without transmitting/receiving capabilities. In this letter, we propose a practical transmission protocol to execute

In this letter, we propose a low-complexity detection algorithm for multi-input-multi-output (MIMO) molecular communication (MC). By virtue of a rising edge in received signals, this detection algorithm is capable of recovering the information bits in MIMO-MC systems. From an engineering point of view, this algorithm can significantly eliminate the impact of inter-symbol interference. It has also proven

We consider the link scheduling problem in wireless mesh networks for capacity maximization. Unlike all previous approaches, ours views capacity in terms of covering a graph’s edges by matchings that are feasible in the sense of the physical interference model, thus leading to a novel fractional edge-chromatic indicator of the graph. Network capacity is then defined as a function of this indicator

Large intelligent surface (LIS) has emerged as a promising new solution to improve the energy and spectrum efficiency of wireless networks. A LIS, composed of a large number of low-cost nearly-passive reconfigurable reflecting elements, enhances wireless communications by reflecting impinging electromagnetic waves. In this letter, we propose a novel passive beamforming and information transfer (PBIT)

In this letter, we propose a trellis-coded non-orthogonal multiple access (NOMA) scheme. The signals for different users are produced by trellis coded modulation (TCM) and then superimposed on different power levels. By interpreting the encoding process via the tensor product of trellises, we introduce a joint detection method based on the Viterbi algorithm. Then, we determine the optimal power allocation

This letter studies the improvement of the achievable end-to-end data rate of ground users assisted with unmanned aerial vehicles (UAVs) and tethered balloons (TBs). The goal is to maximize the end-to-end throughput of a network suffering from the absence of terrestrial infrastructure. First, we solve an integer linear programming problem to optimize the associations. Then, we solve the UAVs’ transmit

One-bit precoding is a recently proposed scheme that enables significant savings in hardware cost and power consumption for massive multiuser multiple-input–multiple-output systems. In this letter, a new minimum mean-square-error (MMSE) precoder is presented for both single- and multiple-antenna mobile stations with enhanced receive processing (ERP) capability. By exploiting the structure embedded

This letter designs a robust beamformer for correlated multiple-input-single-output wiretap channels with multiple noncollaborating passive single-antenna eavesdroppers under channel uncertainty. Assuming that the source has only partial main channel information and statistical wiretap channel information, we seek to maximize the secrecy rate under the transmit power and secrecy outage constraints

We study a deep learning (DL) based limited feedback methods for multi-antenna systems. Deep neural networks (DNNs) are introduced to replace an end-to-end limited feedback procedure including pilot-aided channel training process, channel codebook design, and beamforming vector selection. The DNNs are trained to yield binary feedback information as well as an efficient beamforming vector which maximizes

In this letter, we introduce a novel relaying scheme together with a joint energy beamforming (EB) and time allocation optimization to meet requirements about energy efficiency and hardware constraints of batteryless IoT networks. First, we propose an intelligent relaying scheme using RF-powered gateways as relay nodes to deliver information from batteryless IoT devices to a hybrid access point (HAP)

Aiming at maximizing the energy efficiency (EE) of multicast multibeam satellite communications, we consider the precoding design under the total power and quality of service (QoS) constraints. Since the original EE maximization problem is nonconvex, it is sequentially converted into a concave-convex fractional programming problem by introducing some variables and using the first-order Taylor low bound

In this letter, we investigate the joint beamforming and power splitting design problem in a base station (BS) cluster-based cloud radio access network (C-RAN) with multicast fronthaul, where users are jointly served by BSs within each cluster. Meanwhile, each user can simultaneously obtain information and energy from received signals. On this basis, under predefined minimum harvested energy of each

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.

A low-complexity fully connected hybrid precoding design is proposed for multiuser massive MIMO systems over frequency-selective fading channels. Digital precoding and analog precoding are adaptively designed based on instantaneous channel state information (CSI) and statistical CSI to maximize transmission efficiency. Furthermore, a dynamic partially connected structure and a novel beamforming algorithm

A joint user association (UA) and power control (PC) framework is presented for downlink transmission in cellular networks featuring a macro base station (BS) and a collection of unmanned aerial vehicle BSs. The problem is presented as a nonconvex optimization problem in which the aim is to maximize the network utility by taking into account the PC, load balancing, and user fairness. The UA problem

We investigate the performance of a downlink ultra-dense network (UDN) with directional transmissions via stochastic geometry. Considering the dual-slope path loss model and sectored beamforming pattern, we derive the expressions and asymptotic characteristics of the coverage probability and constrained area spectrum efficiency (ASE). Several special scenarios, namely the physically feasible path loss

In hybrid satellite-terrestrial networks (HSTNs), spectrum sharing is crucial to alleviate the “spectrum scarcity” problem. Therein, the transmit beams should be carefully designed to mitigate the inter-satellite-terrestrial interference. Different from previous studies, this letter considers the impact of both nonlinear power amplifier (PA) and large-scale channel state information at the transmitter

In this letter, we derive exact closed-form expressions for the level crossing rate (LCR) and average fade duration (AFD) of the signal envelope in $\mathcal {F}$ composite fading channels. Using the novel expressions, we then investigate the behavior of the LCR and AFD for different multipath fading and shadowing conditions. It is shown that multipath fading has a more significant effect on the LCR

We propose a new approach for maximizing system throughput while simultaneously obtaining optimal-coverage in terms of minimal radio link failure (RLF) rates in 5G heterogeneous ultra-dense networks (HUDN). To overcome the trade-off issue between the system throughput maximization and the coverage optimization where we can hardly achieve both optimality together, we employ a joint method of “iteration

In this letter, we address the issue of beam-squinting encountered in ultra-wideband millimeter wave mobile communication systems. First, the beam-squinting effects on the antenna array gain and the usable bandwidth of these systems are analyzed. The obtained results show that, in ultra-wideband communication systems, beam-squinting causes loss in array gain and limits the achievable capacity. To mitigate

For multiple active spatial modulation (MASM) technique, this letter formulates the minimum number of transmit antennas $(N_{\mathrm {t}})$ and the required number of active RF chains ( $N_{\mathrm {a}}$ ) to support the following two statements. First, it is proven that MASM can achieve similar spectral efficiency to conventional spatial multiplexing (SMx) with smaller $N_{\mathrm {t}}$ and $N_{\mathrm

Recently, Wireless Power Transfer (WPT) technique using a Radio Frequency (RF) signal has been attracting much attention to sustain the lifetime of wireless Internet of Things (IoT) devices. When a power transmission RF signal operates in the same or near the frequency band as a data signal, it may decrease communication performance. In this letter, we have proposed a novel protocol that enables data

This letter designs a correlation-based secure beamformer for correlated multiple-input-single-output wiretap channels with multiple noncollaborating passive single-antenna eavesdroppers. The outage-probability-constrained secrecy rate maximization problem is investigated under the assumption that the source has accurate main channel information and statistical wiretap channel information. As the correlation

Achieving ultra-high reliability for short packets is a core challenge for future wireless communication systems, as current systems are designed only to transmit long packets based on classical information-theoretic principles. To tackle this challenge, this letter relies on multi-hop unmanned aerial vehicle (UAV) relay links to deliver short ultra-reliable and low-latency (URLLC) instruction packets

This letter describes a real-valued sparse Bayesian learning (SBL) approach for massive multiple-input multipleoutput (MIMO) downlink channel estimation. The main idea of the approach is to introduce a certain unitary transformation into pilots, so as to convert complex-valued channel recovery problems into real ones. Due to exploiting the real-valued structure of the data matrices, the new approach

In this letter, a low-complexity iterative detector with frequency domain equalization is proposed for generalized spatial modulation (GSM) aided single carrier (SC) transmissions operating in frequency selective channels. The detector comprises three main separate tasks namely, multiple-input multiple-output (MIMO) equalization, active antenna detection per user and symbol wise demodulation. This

Freshness of status update packets is essential for enabling a wide range of applications in wireless sensor networks (WSNs). Accordingly, we consider a WSN where sensors communicate status updates to a destination by contending for the channel access based on a carrier sense multiple access (CSMA) method. We analyze the worst case average age of information (AoI) and average peak AoI from the view

This letter investigates the physical layer security issue in unmanned aerial vehicle (UAV) communication networks. Specifically, two UAVs transmit confidential messages to their specified ground destinations by sharing the same spectrum, while a ground eavesdropper attempts to wiretap the confidential messages. In the considered scenario, although mutual interferences arising from spectrum sharing

In the wardriving type method proposed in this letter, the localization of the base stations (BSs) is performed based on unscented Kalman filter with state constraints (UKFC). The state vector is formed by the coordinates and velocities of BSs, and the observations are localization measurements made by a mobile station. The localization measurements show that the BSs are situated on a 3D surface, and

Owing to its unparalleled tractability, the Poisson point process (PPP) has emerged as a popular model for the analysis of cellular networks. Considering a stationary point process of users, which is independent of the base station (BS) point process, it is well known that the typical user does not lie in the typical cell and thus may not truly represent the typical cell performance. Inspired by this

Channel estimation is of crucial importance in massive multiple-input multiple-output (m-MIMO) visible light communication (VLC) systems. In order to tackle this problem, a fast and flexible denoising convolutional neural network (FFDNet)-based channel estimation scheme for m-MIMO VLC systems was proposed. The channel matrix of the m-MIMO VLC channel is identified as a two-dimensional natural image