363 research outputs found
An efficient approximation to the correlated Nakagami-m sums and its application in equal gain diversity receivers
There are several cases in wireless communications theory where the
statistics of the sum of independent or correlated Nakagami-m random variables
(RVs) is necessary to be known. However, a closed-form solution to the
distribution of this sum does not exist when the number of constituent RVs
exceeds two, even for the special case of Rayleigh fading. In this paper, we
present an efficient closed-form approximation for the distribution of the sum
of arbitrary correlated Nakagami-m envelopes with identical and integer fading
parameters. The distribution becomes exact for maximal correlation, while the
tightness of the proposed approximation is validated statistically by using the
Chi-square and the Kolmogorov-Smirnov goodness-of-fit tests. As an application,
the approximation is used to study the performance of equal-gain combining
(EGC) systems operating over arbitrary correlated Nakagami-m fading channels,
by utilizing the available analytical results for the error-rate performance of
an equivalent maximal-ratio combining (MRC) system
An Accurate Approximation to the Distribution of the Sum of Equally Correlated Nakagami-m Envelopes and its Application in Equal Gain Diversity Receivers
We present a novel and accurate approximation for the distribution of the sum
of equally correlated Nakagami-m variates. Ascertaining on this result we study
the performance of Equal Gain Combining (EGC) receivers, operating over equally
correlating fading channels. Numerical results and simulations show the
accuracy of the proposed approximation and the validity of the mathematical
analysis
Dual-Branch MRC Receivers under Spatial Interference Correlation and Nakagami Fading
Despite being ubiquitous in practice, the performance of maximal-ratio
combining (MRC) in the presence of interference is not well understood. Because
the interference received at each antenna originates from the same set of
interferers, but partially de-correlates over the fading channel, it possesses
a complex correlation structure. This work develops a realistic analytic model
that accurately accounts for the interference correlation using stochastic
geometry. Modeling interference by a Poisson shot noise process with
independent Nakagami fading, we derive the link success probability for
dual-branch interference-aware MRC. Using this result, we show that the common
assumption that all receive antennas experience equal interference power
underestimates the true performance, although this gap rapidly decays with
increasing the Nakagami parameter of the interfering links. In
contrast, ignoring interference correlation leads to a highly optimistic
performance estimate for MRC, especially for large . In the low
outage probability regime, our success probability expression can be
considerably simplified. Observations following from the analysis include: (i)
for small path loss exponents, MRC and minimum mean square error combining
exhibit similar performance, and (ii) the gains of MRC over selection combining
are smaller in the interference-limited case than in the well-studied
noise-limited case.Comment: to appear in IEEE Transactions on Communication
Analysis of energy detection of unknown signals under Beckmann fading channels
(c) 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The Beckmann fading is a general multipath fading model which includes Rice, Hoyt and Rayleigh fading as particular cases. However, the generality of the Beckmann fading also implies a significant increased mathematical complexity. Thus, relatively few analytical results have been reported for this otherwise useful fading model. The performance of energy detection for multi-branch receivers operating under Beckmann fading is here studied, and the inherent analytical complexity is here circumvented by the derivation of a closed-form expression for the generalized moment generating function (MGF) of the received signal-to-noise ratio (SNR), which is a new and useful result, as it is key for evaluating the receiver operating characteristics. The impact of fading severity on the probability of missed detection is shown to be less critical as the SNR decreases. Monte Carlo simulations have been carried out in order to validate the obtained theoretical expressions.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech. Proyecto MINECO-FEDER TEC2013-42711-R y TEC2013-44442-P. Junta de AndalucĂa P11-TIC-7109
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