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In this article, a new expression for the joint moment generating function (MGF) of the signal-to-noise ratio (SNR) considering correlated $\eta$ - $\mu$ fading is determined. Based on this result, a new closed-form expression is presented for the bit error probability (BEP) of the rectangular quadrature amplitude modulation ($R$ -QAM) scheme, considering frequency non-selective channel subject to cascaded double correlated $\eta$ - $\mu$ fading and a receiver with dual branch maximum ratio combining (MRC). The signal is received from two links with correlated cascaded double fading in the second link. In addition, a new expression for the outage probability (OP) is derived. All expressions determined in this paper are new and corroborated by simulations performed with Monte Carlo method. [ABSTRACT FROM AUTHOR]

Multi-connectivity (MCo) is considered to be a key strategy for enabling reliable transmissions and enhanced data rates in fifth-generation mobile networks, as it provides multiple links from source to destination. In this paper, we quantify the communication performance of MCo in terms of outage probability and throughput. For doing so, we establish a simple, yet accurate analytical framework at high signal-to-noise ratio (SNR), in which the number of links, the spectral efficiency, the path loss, and the SNR are incorporated, giving new insights into the potentials of MCo as compared with the single-connectivity (SCo). These are our main contributions: 1) finding the exact coding gain of the outage probability for parallel block-fading channels; 2) quantifying the performance improvement of MCo over SCo in terms of SNR gain; and 3) comparing optimal and suboptimal combining algorithms for MCo at the receiver side, namely joint decoding, selection combining, and maximal-ratio combining, also in terms of SNR gain. In addition, we apply our analytical framework to real field channel measurements and thereby illustrate the potential of MCo to achieve high reliability and high data rates in real cellular networks. [ABSTRACT FROM AUTHOR]

The Gamma–Gamma distribution has recently emerged in a number of applications ranging from modeling scattering and reverberation in sonar and radar systems to modeling atmospheric turbulence in wireless optical channels. In this respect, assessing the outage probability achieved by some diversity techniques over this kind of channels is of major practical importance. In many circumstances, this is related to the difficult question of analyzing the statistics of a sum of Gamma–Gamma random variables. Answering this question is not a simple matter. This is essentially because outage probabilities encountered in practice are often very small, and hence, the use of classical Monte Carlo methods is not a reasonable choice. This lies behind the main motivation of this paper. In particular, this paper proposes a new approach to estimate the left tail of the sum of Gamma–Gamma variates. More specifically, we propose robust importance sampling schemes that efficiently evaluates the outage probability of diversity receivers over Gamma–Gamma fading channels. The proposed estimators satisfy the well-known bounded relative error criterion for both maximum ratio combining and equal gain combining cases. We show the accuracy and the efficiency of our approach compared with naive Monte Carlo via some selected numerical simulations. [ABSTRACT FROM PUBLISHER]

Prior results on exact error rates and outage probabilities of diversity receptions over arbitrarily correlated fading channels involve intractable nested integrals, which makes the performance analyses challenging to carry out. In this paper, we derive asymptotic expressions and asymptotically tight bounds for error rates and outage probabilities of diversity receptions (including maximal-ratio combining, selection combining, and equal-gain combining) over arbitrarily correlated Beckmann fading channels. These new asymptotic performance expressions reveal insights into the diversity systems over arbitrarily correlated Beckmann fading channels, and the accuracy of the asymptotic performance expressions is explicitly quantified by the performance bounds. Using these analytical tools, one can assess the performance of the diversity reception systems over arbitrarily correlated Beckmann fading channels without resorting to time-consuming Monte Carlo simulation or numerical multifold integration. [ABSTRACT FROM PUBLISHER]

This paper presents simple tight upper bound expressions for the average symbol error probability and bit error probability of coherent M-ary biorthogonal signals over fading channels with diversity reception. The upper bounds, which do not involve numerical integration and are expressed with only elementary functions, can be efficiently evaluated. In addition, they are valid for different diversity-combining techniques, as well as for arbitrarily correlated and/or nonidentically distributed channels. The tightness of the derived tipper bounds is clarified under various channel conditions. Numerical results are also provided to demonstrate the impact of nonidentical channels on the system average error performance. [ABSTRACT FROM AUTHOR]

Novel single-integral representations for the bivariate probability density function and cumulative distribution function of two correlated Rician random variables are derived. The solutions are expressed in terms of well known functions which are available in common mathematical software. The two random variables are not necessarily identically distributed as required by some past solutions. The new form of the bivariate Rician cumulative distribution function is applied to give a new expression for the outage probability of dual selection combining diversity operating in correlated Rician fading. [ABSTRACT FROM AUTHOR]