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In concurrent spectrum sharing scenarios between radars and wireless communication systems, one strict approach to protect the radar from undesired interference is locating the base stations outside a guard (or exclusion) zone of the radar. As a result, users inside that zone experience bad communication coverage. This paper uses Reconfigurable Intelligent Surfaces (RISs) to improve the base station coverage of users in the radar exclusion zone. The paper shows, through analysis and simulation, that joint optimization of base station and RIS locations improves the probability of coverage in the exclusion zone over the shared spectrum without disturbing the radar operation. [ABSTRACT FROM AUTHOR]

Millimeter wave (mm-wave) communication is one of the key enabling technologies for meeting the requirements of the fifth generation (5G) wireless communication systems. It is, therefore, essential to have accurate information about the mm-wave radio channel characteristics for successful deployment of these systems. There are many recent mm-wave channel characterization measurements reported worldwide. However, no such measurements were reported in the Arabian Peninsula, where the environment along with the building design and architecture are different from other regions in the world. This paper tries to fill that gap and presents the results of an mm-wave measurement campaign conducted at the American University of Sharjah (AUS) campus in the United Arab Emirates (UAE) during the period of November 2018 to January 2019. The results of the large-scale characterization (path loss and shadow fading) are presented for both indoor and outdoor environments at 28 GHz. Furthermore, the penetration loss and reflection coefficients for materials commonly used in the facades of building structures in the UAE are measured at the same frequency. [ABSTRACT FROM AUTHOR]

We present two novel methods for the generation of Fox's $H$ -function distributed random variables (RVs), which have been recently used to model fading in various wireless communication scenarios. The first proposed method is based on the use of standard normal RVs, whereas the second is based on the use of Gamma RVs. Using Monte Carlo simulations, the proposed methods are tested and are shown to provide indistinguishable results from the corresponding analytical $H$ -function probability density functions (PDFs) for a diverse set of parameters. Moreover, as an application, simulated ergodic capacity and average bit error rate results obtained using the proposed methods are compared to analytical expressions previously obtained in the literature and perfect agreement is observed. Our results also provide valuable insights into what constraints on the $H$ -function parameters are sufficient to guarantee valid $H$ -function PDFs. [ABSTRACT FROM AUTHOR]

This paper addresses throughput improvement in millimeter-wave (mmWave) mesh networks via two novel distributed scheduling algorithms. The first one uses packet aggregation and block acknowledgment (ACK) that were introduced in the IEEE Std 802.11e-2005 for WiFi. Specifically, a distributed time-division multiplexing scheduling algorithm, which targets increasing the network capacity via reserving as many contiguous slots as possible for each node, is proposed thus enabling packet aggregation. This algorithm achieves its goal when the operating signal-to-noise ratio (SNR) is significantly high. If that is not the case, the second proposed algorithm can be used. It is a distributed one that starts initially with a random feasible schedule determined cooperatively between nodes. The algorithm then tries to reach better feasible schedules via parallel and successive local searches without violating feasibility constraints. Extensive simulations show that the first algorithm improves the network throughput by almost compared to the well-known memory-guided directional medium access control (MDMAC) due to reducing the transmission overhead. The second proposed algorithm is shown to increase the number of reserved slots by about over MDMAC. Both algorithms are shown to either increase or almost maintain the same degree of fairness among the nodes as quantified by Jain's fairness index. [ABSTRACT FROM AUTHOR]

We derive novel exact closed-form expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the product and ratio of products of an arbitrary number of independent non-identically distributed (i.n.i.d) extended generalized-K (EGK) variates. The expressions are given in terms of the Meijer’s G-function and can be computed easily using commonly available mathematical software tools. They also subsume those for arbitrary combinations of other well-known variates and can be directly utilized in performance evaluation of wireless communication systems under different scenarios. We present various analytical results that are verified via Monte-Carlo simulations for both the PDF and CDF as well as their application in multiple practical scenarios. [ABSTRACT FROM AUTHOR]

In this paper, we characterize the achievable (linear) degrees of freedom (DoFs) of the K-user single-input single-output (SISO) interference channel with blind interference alignment (BIA) using staggered antenna switching. In this scheme, each transmitter is equipped with one conventional antenna, and each receiver is equipped with one reconfigurable (multimode) antenna. Assuming that the channel is known to the receivers only, we show that by using linear BIA with staggered antenna switching at the receiver, a sum DoF of \text{2}K/(K+\text{2}) is achievable. This result implies that in using BIA, we can double the DoF achieved by orthogonal multiple-access schemes for a large number of users. Moreover, we propose a systematic algorithm to generate the transmit beamforming vectors and the reconfigurable antenna switching patterns, showing that it can achieve the \text{2}K/(K+\text{2})$ sum DoF for any K$. Finally, we apply this algorithm to the four-user SISO interference channel and demonstrate that \text{4}/\text{3} sum DoF is indeed achievable. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a combined analytical and simulation framework for performance evaluation of the forward link in the cdma2000 evolution for data only (1xEV-DO) cellular systems with throughput and spectral efficiency being used as performance metrics. A closed form expression for the aggregate average throughput is derived in terms of system-dependent parameters and a discrete random process that reflects the stochastic behavior of the transmission channel. The random process is expressed in terms of the cumulative distribution function (CDF) of the users signal-to-interference-plus-noise ratio (SINR). Quantitative results for throughput and spectral efficiency are presented for a variety of users distribution models, base station antenna types and frequency reuse factors for the cases of sectorized and non-sectorized cells. Furthermore, we study the impact of the cell radius on the system performance. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• A Gibbs sampling-based parameters estimation algorithm for the EGK distribution is presented. • First attempt to address ML-based estimators for the EGK distribution. • Numerical and simulation results show that the proposed method provides an efficient and mathematically tractable approach to achieve this goal. • Compared to the classical moment-matching method, the proposed method can better capture cases of heavy-tail. We present a novel approach for estimating the parameters of the extended generalized- K (EGK) distribution commonly used as a fading model in wireless and optical communications links. The proposed method is based on the Gibbs sampling technique and does not require solving nonlinear equations nor performing numerical integrations. Numerical and simulation results are presented showing that the estimated and original distributions are virtually indistinguishable and formal metrics like Kullback-Leibler (KL) divergence, the mean integrated squared bias (MISB), the mean integrated variance (MIV) and the mean integrated squared error (MISE) all show excellent agreement between the two as well. [ABSTRACT FROM AUTHOR]