2,826 research outputs found
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
A simple importance sampling technique for orthogonal space-time block codes on Nakagami fading channels
In this contribution, we present a simple importance sampling technique to considerably speed up Monte Carlo simulations for bit error rate estimation of orthogonal space-time block coded systems on spatially correlated Nakagami fading channels
BER of MRC for M-QAM with imperfect channel estimation over correlated Nakagami-m fading
In this contribution, we provide an exact BER analysis for M-QAM transmission over arbitrarily correlated Nakagami-m fading channels with maximal-ratio combining (MRC) and imperfect channel estimation at the receiver. Assuming an arbitrary joint fading distribution and a generic pilot-based channel estimation method, we derive an exact BER expression that involves an expectation over (at most) 4 variables, irrespective of the number of receive antennas. The resulting BER expression includes well-known PDFs and the PDF of only the norm of the channel vector. In order to obtain the latter PDF for arbitrarily correlated Nakagami-m fading, several approaches from the literature are discussed. For identically distributed and arbitrarily correlated Nakagami-m channels with integer m, we present several BER performance results, which are obtained from numerical evaluation and confirmed by straightforward computer simulations. The numerical evaluation of the exact BER expression turns out to be much less time-consuming than the computer simulations
Outage Probability in Arbitrarily-Shaped Finite Wireless Networks
This paper analyzes the outage performance in finite wireless networks.
Unlike most prior works, which either assumed a specific network shape or
considered a special location of the reference receiver, we propose two general
frameworks for analytically computing the outage probability at any arbitrary
location of an arbitrarily-shaped finite wireless network: (i) a moment
generating function-based framework which is based on the numerical inversion
of the Laplace transform of a cumulative distribution and (ii) a reference link
power gain-based framework which exploits the distribution of the fading power
gain between the reference transmitter and receiver. The outage probability is
spatially averaged over both the fading distribution and the possible locations
of the interferers. The boundary effects are accurately accounted for using the
probability distribution function of the distance of a random node from the
reference receiver. For the case of the node locations modeled by a Binomial
point process and Nakagami- fading channel, we demonstrate the use of the
proposed frameworks to evaluate the outage probability at any location inside
either a disk or polygon region. The analysis illustrates the location
dependent performance in finite wireless networks and highlights the importance
of accurately modeling the boundary effects.Comment: accepted to appear in IEEE Transactions on Communication
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