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In the studies of 5th generation (5G) wireless communication systems, an alternative method to orthogonal frequency division multiplexing (OFDM) used for 4th generation (4G) systems is still being investigated. OFDM with offset quadrature amplitude modulation (OFDM/OQAM) is one of these alternatives. Due to the reasons such as absence of cyclic prefix (CP) in its structure and perfect separation between...
In this paper, multiuser multiple-antenna (MUMIMO) relay networks employing opportunistic scheduling and operating in the presence of rayleigh fading and co-channel interference are analyzed Notwithstanding the system complexity, due to the newly found complementary moment generating function transform (CMGF) operator, an exact expression for the capacity under general conditions is obtained. Moreover,...
Deploying small cells (pico, femto or relays) in a macro-cell network is an advantageous solution to increase system capacity. However, small cells usually transmit with a weaker power compared to macro-cells, this fact causes a serious interference problem for these former. Range Expansion technique is among the solutions proposed to overcome this problem. The idea is to bias the received signal...
By relying on a stochastic geometry abstraction modeling for the locations of the base stations and by considering an accurate channel model based on measurements, the author of [1] has recently proposed a tractable mathematical framework for evaluating coverage and rate of millimeter wave cellular networks. The approach proposed in [1] however, relies on a noise-limited approximation for millimeter...
In this paper, we study a resource efficient coordinated beamforming design for the downlink of heterogeneous multiuser system. The objective function is formulated as maximizing the weighted sum per-cell resource efficiencies subject to per-user quality of service demands and per-cell transmit power constraints, which is hard to tackle due to the weighted sum-of-ratios form and the non-convex nature...
A multi-pair large-scale multi-antenna relaying system is considered in this paper. We investigate the energy efficiency (EE) performance by taking the circuit power consumption into account when maximum ratio combining/maximum ratio transmission is explored at the relay station (RS). By utilizing the law of large numbers, an analytical expression of EE is derived. Based on this, we characterize the...
Existing work on the precoding scheme for multibeam satellite systems assumes the availability of perfect channel state information (CSI) at the satellite transmitter. Unfortunately, this assumption is not applicable to mobile satellite systems because of long propagation delays, and this is especially true for the geostationary earth orbit (GEO) satellite systems. In this paper, we present a linear...
This paper focuses on decode-and-forward (DF) OFDM full duplex relaying (FDR) systems with multiple relays, where residual loop interference is taken into account. Closed-form and high-SNR approximate expressions for the outage probability are derived. Simulations are carried out to validate the derived outage performance and compare the performance of OFDM FDR with that of OFDM half duplex relaying...
Full-duplex multiple-input-multiple-output (MIMO) relaying is capable of providing coverage for remote users with low power consumption, by exploiting the spatial dimensions of MIMO to suppress different types of interference, including self interference (SI) and multi-user interference (MUI). In a general network with multiple full-duplex MIMO relays, inter-relay interference (IRI) emerges and degrades...
Comparative analysis of extreme properties of selective signals, built on the basis of quadratic and cubic splines by means of eye-diagram aperture value criteria and energy redistribution in the signal, is carried out. It is shown that with optimum parameter selection one can obtain signals with necessary properties, it leads to simplifying the process of its practical realization at the stage of...
Despite the growing deployment of 4G networks, the capacity of cellular networks is still insufficient to satisfy the ever-increasing bandwidth demand of mobile applications. Given the common interest of mobile users, Device-to-Device (D2D) communication has emerged as a promising solution to offload cellular traffic and enable proximity-based services. One of the main detriments for D2D communication...
In this paper, we study the link scheduling problem in wireless cooperative communication networks, in which receivers are allowed to combine copies of a message from different senders to combat fading. We formulate a problem called cooperative link scheduling problem (CLS), which aims to find a schedule of links that uses the minimum number of time slots to inform all the receivers. As a solution,...
A broadly applicable perturbation-based approach is demonstrated for estimating the impact of intra-channel fiber nonlinearities on system performance. The estimated performance for DP-QPSK, DP-8QAM, and DP-16QAM exhibits good agreement with both simulation and experimental results.
Massive Multiple-Input Multiple-Output (MIMO) is foreseen to be one of the main technology components in next generation cellular communications (5G). In this paper, fundamental limits on the performance of downlink massive MIMO systems are investigated by means of simulations and analytical analysis. Signal-to-noise-and-interference ratio (SINR) and sum rate for a single-cell scenario multi-user...
Radiated interference environments can significantly degrade the performance of the digital communication systems that are widely used today. Problems from such intersystem interference might need to be analyzed beforehand or as problems occur. Another application where such analysis is of interest is in systems using dynamic allocation of spectrum, where it serves as basis for spectrum allocation...
In this paper, we investigate mode selection for coordinated multi-point (CoMP) transmission in downlink LTE-A networks, where inter-cluster interference exists. The proposed scheme selects the single-cell (SC) or coordinated beamforming (CB) transmission mode according to interference level to maximize the weighted sum rate with fairness consideration. To formulate the optimization problem, an approximated...
In this paper, we build a unified analytical framework that allows for analysis and comparison of three device-to-device (D2D) mode selection schemes proposed in the literature to date, namely the distance cut-off scheme, the link gain scheme and the guard zone scheme. In the framework we adopt Poisson point process (PPP) assumptions to model the cellular and D2D interference, respectively. Using...
The throughput of small cell networks (SCNs) is limited by intercell interference. Except numerous techniques of interference coordination, simply caching several popular files at each user provides an alternative approach to reduce interference by pre-offloading. This becomes possible nowadays due to the facts that the cost of memory devices is reducing quickly and content delivery is gradually dominating...
Within the framework of Monte Carlo simulation, this paper derives a Markov chain Monte Carlo (MCMC) algorithm for efficient detection in multiple-input multiple-output (MIMO) systems using the non-orthogonal multi-carrier waveform termed generalized frequency division multiplexing (GFDM). The proposed MCMC algorithm performs the detection task in frequency domain. Its adopted proposal distribution...
In this paper, we propose a new method of secrecy signal and artificial noise (AN) transmission for a MISO wiretap channel in wireless cellular networks. We first design the secrecy signal beamformer such that its power leakage to the unintended directions is minimized, then we concentrate the AN on the directions with higher risk of information leakage, rather than broadcast it isotropically, such...
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