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Some of the future wireless networks are related to the provision of higher data rates and lower energy consumption. In contrast to the clear increasing spectrum demand, bandwidth is a limited resource. Cooperative diversity allows to increase the spectral efficiency and the reliability of the communication. However, in scenarios with high node density and high mobile data traffic volume the collaboration...
An experimental set-up and procedure for emulating realistic fading channels in a reverberation chamber is described in this contribution. Of particular interest is the generation of power delay profiles of urban-macro and -micro channels defined in the 3GPP Spatial-Channel-Model-Extended (SCME). The input signal to the chamber is generated by convolving a rectangular pulse with delay taps using a...
Considering unreliable wireless backhaul connections across transmitters, we investigate the outage performance of a finite-sized selective relaying system with M transmitters and N relays under Nakagami-m fading channels. To send the source message to the destination, the transmitter-relay pair providing the highest end-to-end signal-to-noise ratio is selected for transmission. The backhaul reliability...
This paper considers a fast fading wireless powered wiretap channel, where an energy constrained information source, powered by a dedicated power beacon, sends a secret message to a legitimate user using the artificial noise (AN) scheme in the presence of a passive eavesdropper. Based on a two-phase time division protocol, the ergodic secrecy throughput is derived. Furthermore, the optimal time-switching...
The evaluation of an IoMT system needs to include the assessment of LPI, LPE, or LPD. To provide a building block for these metrics, in this paper, we introduce the notion of the information-theoretic secrecy. In particular, we focus on the shadowing fading with the log-normal distribution. We extend a recent analysis for uncorrelated eavesdroppers to the case of correlated ones. Then we derive the...
We propose a wireless power transfer (WPT) based underlay spectrum sharing scheme, where a primary user (PU) needs to harvest wireless energy from an access point (AP) and then transmit its data to AP using the harvested energy. In the same area, a secondary transmitter (ST) intends to communicate with a secondary receiver (SR). The secondary data can be transmitted along with the WPT, which can on...
With the ability to reconstruct signals from a highly incomplete number of samples, Compressive Sensing (CS) has been proposed in bandwidth-constrained scenarios like remote sensing, where signals exist some degree of redundancy. In CS, reconstruction approaches are of great importance. However, current reconstruction approaches are of highly computational complexity because they use greedy or convex...
This paper investigates a large-scale cognitive radio network with primary users (PUs) and secondary users (SUs) spatially and randomly distributed. All the PUs need to harvest wireless energy from their associated access points (APs) before transmitting information. To combat the low efficiency of wireless power transfer caused by the severe path-loss, we propose to apply an energy cooperation zone...
In this paper, we analyze the TCP Cubic throughput performance over a Nakagami-m slow-fading wireless channel with impacts of adaptive modulation and coding (AMC) schemes. The loss event, which includes a transport-layer congestion loss and physical-layer random packet loss is first analyzed thanks to corresponding finite-state Markov models. The average normalized throughput can be, thus, calculated...
Cloud-fog radio access is a promising technology in evolving wireless communication systems, but its success depends on security. It is fundamental to conduct the secrecy analysis in the physical layer due to the special architecture of CF-RAN. In this paper, we investigate the secrecy impacted by general path-loss effects. We show that the mathematical kernel is the Weibull distribution function...
In this paper, we consider a two-tier cellular network consisting of a primary macro cell base station (PMBS) which is overlaid by cognitive small cell base stations (CSBSs) to achieve efficient spectrum utilization. The deployment of two-tier cellular networks can provide higher capacity for the system but also causes cross-tier, intra-tier, and inter-tier interference within the cellular networks...
In this paper, we study the issue of selecting the transmission power (energy per symbol) and power allocation between pilot and data symbols to maximize the energy efficiency (EE). We consider the system that has a slow-fading channel and employs a minimum mean square error (MMSE)-based channel estimation scheme for a pilot symbol-assisted modulation. We derive a closed-form expression for a lower...
In this paper, we propose a cross-layer design framework for transmitting Markov modulated Poisson process (MMPP) traffic over cognitive cooperative networks, which considers the energy efficient transmissions for different delay-aware packets. The adaptive modulation and coding (AMC) is used in the cooperative transmission system. The queueing process is considered in the buffer aided relay and source...
This paper investigates the link selection policy for secure communications over a buffer-aided two-hop communication link. It is assumed that a source wishes to send information to a destination with the aid of a trusted half-duplex relay node compromised by a passive eavesdropper, and that there is no direct link between the source and the destination. The buffer-aided relay forwards the information...
This paper studies an uplink simultaneous wireless information and power transfer (SWIPT) system with non-orthogonal multiple access (NOMA), consisting of two users and one energy-harvesting access point (AP). The users transmit their independent information simultaneously to the AP which harvests energy and decodes information at the same time by dynamic power splitting (DPS). We focus on the ergodic...
Due to dense small cells deployment in a heterogeneous network, the backhaul links among the small cells and macro cell are band-limited when they share the same spectrum with the user equipments. To mitigate the intra- and inter-cell interference caused by the band-limited backhaul, we propose a recursive estimation-based zero-forcing beamforming (RE-ZFBF) scheme. Based on initial values obtained...
In this paper, wideband and ultra wideband (UWB) radio propagation within a small aircraft was measured and statistically analyzed. Wideband including UWB wireless technology has been considered for replacing wire harnesses used in aircrafts, spacecraft, and other closed-or semi-closed spaces because of its anti-multipath capabilities and possible low power consumption. Adaptation of wireless technologies...
Spectrum aggregation (SA) is a technique through which a user performs transmission through multiple channels to maximize capacity. In this paper, adaptive SA with optimal channel selection and power allocation for multiuser multichannel access in spectrum sharing wireless networks is proposed. The main objective is to maximize secondary user (SU) nodes capacity subject to: quality-of-service (QoS)...
Evolution of modern communications and radar systems have steadily increased the demand on modelling the propagation effects with real world scenarios for various signal types. The main purpose of this research is to create a flexible, generic and realistic Radio Frequency (RF) environment simulator including both radar and communication signals. Software defined radio (SDR) platform has been utilized...
Many wireless networks operate in the presence of distance-dependent path–loss in a fading environment with a Poisson interference field. In these networks, the aggregate interference can be modeled as an α-stable process with a known characteristic function. In this study, the authors revisit performance analysis of wireless systems operating in a Nakagamim fading channel. In particular, our emphasis...
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