The complex α-μ fading channel with OFDM application

The aims of this paper are threefold: (i) to present a model for the complex - fading channel; (ii) to propose an efficient, simple, and general method to generate complex - samples; (iii) to make use of this channel in order to assess the bit error rate performance of an OFDM system. An analytical framework is then used, whose output is validated through Monte Carlo simulation. Several important conclusions concerning the system performance as a function of the channel parameters, namely, nonlinearity, clustering, and power imbalance of in-phase and quadrature components, are drawn2017Recent advances in RF propagation modeling for 5G systemsFINANCIADORA DE ESTUDOS E PROJETOS - FINEP01.14.0231.0

Performance of IEEE 802.11 in Wireless Mesh Networks

Abstract -This paper addresses the performance of the IEEE 802.11 MAC protocol in a wireless mesh network. The aim is to assess under which conditions the protocol's performance might be acceptable, in particular for delay sensitive traffic. A number of different scenarios is considered, with varying number of gateways, different sizes for the group of users, as well as different transmission and carrier sensing ranges. It is shown that the IEEE 802.11 performs poorly on heavy traffic, in particular for data flows subject to multiple hops. In addition, the protocol fails to dispense the available bandwidth fairly to the requesting nodes. Improvements can be obtained by minimizing the number of hops required for the traffic to reach its destination. This can be achieved by increasing the number of gateways. Another alternative is to increase the transmission range, at the cost of spatial reuse. However, the latter option only translates into better performance if the carrier sense range is also decreased

The product of two α-μ variates and the composite α-μ multipath–shadowing model

In this paper, the product of two independent and nonidentically distributed (i.n.i.d.) alpha-mu variates is considered. Exact reasonably simple closed-form expressions for the probability density function (pdf), the cumulative distribution function (cdf), and the moments of the resulting random variable (RV) are derived. These results find a wide range of applications in a number of fields, such as radar communications, multihop systems, multiple-input-multiple-input links, and cascaded communications in general. In particular, they are used here to describe a novel alpha-mu/alpha-mu composite multipath-shadowing fading model. Because the alpha-mu model alone comprises a substantial number of useful fading environments, its alpha-mu/alpha-mu composite version leads to a variety and an immense amount of composite fading distributions. The novel expressions for this rather flexible scenario compute instantaneously, constituting a powerful tool to characterize wireless fading channels6462720272

Product of α– μ variates

Exact closed-form expressions for the probability density function and the cumulative distribution function for the product of an arbitrary number of independent non-identically distributed α-μ variates are derived. The expressions are given in terms of the Meijer G-function, and in terms of afinite sum of hypergeometric functions, and can be easily computed by means of well-known mathematical software tools. As a consequence of the generality of the α-μ distribution as well as of the results, these statistics comprise those for the product of arbitrary combinations of other useful distributions such as One-Sided Gaussian, Negative Exponential, Rayleigh, Weibull, Gamma, and Nakagami-m. As an application example, the outage probability for the cascade channel is presented4663764