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Recent advancements in the self-interference (SI) cancellation capability of low-power wireless devices pave the way of implementing full-duplex (FD) self-backhauling in smallcell networks. FD self-backhauling allows exploiting the radio spectrum used by the radio access network (RAN) for backhaul links as well as access links concurrently. This paper characterizes the performance of FD self-backhauling...
Wireless access networks over high speed railway (HSR) encounters many challenges, e.g., the fluctuations of wireless channels, frame synchronization, and geographical obstacles. Since increasing signal quality can bring benefit against channel impairments, the key to solve these challenges is to enhance radio signal strength over HSR. Combining radio over fiber with distributed antennas system (RoF-DAS)...
In this paper, we study cooperative spectrum sensing over composite fading channels. First, we consider the Mixture of Gaussian distribution to model the composite channel statistics and derive a simple generic approximation for the average probability of detection which can be efficiently applied to any composite fading channel. Second, we derive the optimal voting rule for hard combining in cooperative...
Device-to-device (D2D) communication, where user equipments (UEs) in proximity communicate directly with each other, is an alternative technology for densification in future wireless communications featuring extremely dense and heterogeneous networks. The intrinsic characteristics of D2D communication include (1) limited energy capacity of battery powered UEs, (2) necessary power consumption to maintain...
This paper addresses the problem of rate selection for the cooperative hybrid automatic repeat request with chase combination (HARQ-CC) system, where time correlated Nakagami-m fading channels are considered. To deal with this problem, the closed-form cumulative distribution function (CDF) for the combine SNRs through maximal ratio combining (MRC) is first derived as a generalized Fox's H̄ function...
In this paper, the end-to-end performance of a multihop free-space optical system with amplify-and-forward channel-state-information-assisted relays using intensity modulation with direct detection technique over Gamma-Gamma turbulence fading with pointing error impairments is studied. More specifically, novel closed-form expressions for the moment generating function, the cumulative distribution...
In this paper, we investigate the performance of a dual-hop amplify-and-forward (AF) relay system with beamforming (BF), where the source and destination are both equipped with multi-antenna, which are correlated in space, while the relay has a single antenna corrupted by multiple co-channel interferences (CCIs). We first derive the closed-form expression for the outage probability (OP) of the output...
Carrier aggregation (CA) is a technique introduced in LTE-Advanced to achieve a higher throughput by increasing bandwidth. In this work, the spectrally efficient frequency division multiplexing (SEFDM) bandwidth compression technique is utilized to enhance CA performance. This work reports experimental demonstration of SEFDM and shows that up to 7 component carriers (CCs) can be aggregated in a given...
Technologies envisaged for a 5G communications system provide interesting prospects which are beneficial for co-operative positioning. Since 5G development is in the early stages, there is a unique opportunity to develop and integrate mobile radio based positioning technology in 5G from the beginning. In this paper we discuss 5G concepts to ensure seamless positioning by cooperative positioning. In...
From the results of the ray-tracing simulation of 28 GHz frequency band over downtown of Ottawa and New York University campus, we propose 3D large-scale channel models for urban city which are applicable to a mmWave version of 3D spatial channel model. Due to the change of geographical topology dimension from 2D to 3D, the height information of the transmitter should be reflected to the parameters...
The pilot reuse issue in massive multi-input multi-output (MIMO) antenna systems with interfering cells is closely examined. This paper considers scenarios where the ratio of the channel coherence time to the number of users in a cell may be sufficiently large. One such practical scenario arises when the number of users per unit coverage area cannot grow freely while user mobility is low, as in indoor...
We investigate the information-theoretic throughout achievable on a fading communication link when the receiver is equipped with one-bit analog-to-digital converters (ADCs). The analysis is conducted for the setting where neither the transmitter nor the receiver have a priori information on the realization of the fading channels. This means that channel-state information needs to be acquired at the...
For massive MIMO system, few research has been done for multipath frequency selective fading model among all literatures. Hence, in this paper we propose a 2-stage multibranch linear MOE (minimum output energy) receiver which collects symbols from different paths to deal with frequency selective fading environment. Due to the big number of antennas, we are using sample covariance matrix other than...
Spectrum Sensing (SS) constitutes the most critical task in Cognitive Radio ( CR) systems for Primary User (PU) detection. Cooperative Spectrum Sensing (CSS) is introduced to enhance the detection reliability of the PU in fading environments. In this paper, we propose a soft decision based CSS algorithm using energy detection by taking into account the noise uncertainty effect. In the proposed algorithm,...
Cognitive radio is able to effectively increase spectral utilization. However, cooperative spectrum sensing gives malicious users chances to interfere with its decision processes. If a mobile secondary user's energy detection results become unreliable, conventional trust-value based cooperative spectrum sensing algorithms, which are used to resist malicious attacks, cannot distinguish whether it's...
We consider a cooperative communication system where source and destination exchange messages with the help of relays. We investigate a scenario where the relays are not equipped with fixed batteries but collect the required energy (for processing and transmission purposes) via simultaneous wireless information and power transfer (SWIPT). We assume the relays are randomly distributed in the scenario...
This paper focuses on the beneficial effects brought by the presence of multiple receivers to a slotted Aloha scheme. Starting from an analytical angle, we review and compare some recent results that characterize the throughput of such systems under different channel models, based on the assumption that incoming powers at receivers follow an i.i.d. distribution. While practical in some scenarios,...
In this paper, an optimal power allocation scheme for a simple lossy-forwarding relaying system is provided. Here, we extend our previous work of optimal power allocation of Slepian-Wolf relay system with constant source-relay error probability, to such that block Rayleigh fading is assumed for all transmission channel and lossy transmission is assumed in source-relay channel. Since data sequences...
Handover decisions and mobility management in modern communication networks are carried out using signal measurements taken at user equipment (UE), obtained from neighboring base stations. Therefore, time and frequency selective characteristics of the radio propagation channel can seriously degrade the handover performance. In this paper, we investigate the impact of channel fading on the handover...
In this article, we present a Cloud empowered Cognitive Inter-Cell Interference Coordination (C2-ICIC) scheme for small cellular networks. The scheme leverages a recently proposed cloud radio access network (C-RAN) architecture for enabling intratier coordination and relaxes the need for inter-tier coordination by adopting the phantom cell architecture. Employing tools from stochastic geometry, we...
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