On the application of the sum of generalized Gaussian random variables: maximal ratio combining

In most wireless communication systems, the additive noise is assumed to be Gaussian. However, there are many practical applications where non-Gaussian noise impairs the received signal. Examples include co-channel and adjacent channel interference in mobile cellular systems, impulsive noise in wireless and power-line communications, ultra-wide-band interference and multi-user interference in wireless systems, and spectrum sensing. To cover this issue, we consider in this paper the application of the sum of generalized Gaussian (GG) random variables (RVs). To this end, we consider single-input multiple-output (SIMO) systems that operate over Nakagami-m fading channels in the presence of an additive white generalized Gaussian noise (AWGGN). Specifically, we derive a closed-form expression for the bit error rate (BER) of several coherent digital modulation schemes using maximal ratio combining diversity in the Nakagami-m fading channels subject to an AWGGN. The derived expression is obtained based on the fact that the sum of L GG RVs can be approximated by a single GG RV with a suitable shaping parameter. In addition, the obtained BER expression is valid for integer and non-integer value of the fading parameter m. Analytical results are supported by Monte-Carlo simulations to validate the analysis.     

Outage probability analysis of multi-hop relayed wireless networks over $$\alpha -\mu $$ fading channels

In this paper, we study the end-to-end outage probability performance of Amplify and Forward (AF) and Decode and Forward (DF) multi-hop wireless communication systems operating over independent but not necessarily identical \(\alpha -\mu \) fading channels. To this end, we derive an expression for the moment generating function of the reciprocal of the end-to-end signal-to-noise ratio, and then use this expression to evaluate the end-to-end outage probability of the AF system by numerically inverting the Laplace transform. We also derive an expression for the end-to-end outage probability of the DF system.     

Capacity analysis of dual-hop wireless communication systems over α–μ fading channels

In this paper, we consider a dual hop wireless communication system with a non-regenerative relay and study its performance over the α–μ fading channel. Specifically, we derive closed-form expressions for the moment generating function (MGF), the cumulative distribution function (CDF), and the probability density function (PDF) of the harmonic mean of the end-to-end signal-to-noise ratio (SNR) assuming the α–μ fading model. We also derive closed-form expressions for the end-to-end capacity and outage capacity of the system herein. The obtained expressions can be reduced to study the performance of dual hop communication systems over other fading channel models by using the proper values for the α and μ parameters, such as Rayleigh, Nakagami-m, and Weibull fading models. Numerical results are provided for the obtained expressions and conclusion remarks are drawn.     

Outage probability analysis of multi-hop relayed wireless networks over η − μ fading channels

In this paper, we study the outage probability of multi-hop relayed wireless networks assuming independent but not necessarily identically distributed η − μ fading channels. In our analysis, we consider both regenerative and non-regenerative relays. To this end, we provide a novel expression for the moment generating function (MGF) of the reciprocal of the end-to-end signal-to-noise ratio (SNR) and we then use this expression to evaluate the end-to-end outage probability of the non-regenerative network via numerical inversion of the Laplace transform. Moreover, we provide a novel expression for the end-to-end outage probability of the regenerative network. It is worth mentioning here that the derived expressions can be reduced to several other expressions, such as Rayleigh, Nakagami-m, Hoyt, and One-sided Gaussian fading channels. Numerical and simulation results are provided to show the tightness of the derived expressions.     

CDMA-SFBC Downlink Performance

In this paper a generic code division multiple access (CDMA)-space frequency block coded (SFBC) system for downlink transmission is proposed. Closed form expressions for the bit error rate (BER) performance of the proposed CDMA-SFBC downlink system are derived and numerically evaluated considering different scenarios. The closed form BER expressions are derived for both the M-ary phase shift keying (MPSK) and the M-ary quadrature amplitude modulation (MQAM) techniques considering different CDMA-SFBC configurations. The BER expressions are evaluated for a wide range of system parameters assuming Rayleigh fading. These parameters include M-ary size and channel estimation error variance. Such evaluations are crucial not only for system performance prediction, but also for network management, monitoring and future cross-layer design.     

A unified framework for performance evaluation over generalized fading channels

In this paper, we present a unified framework to analyze the performance of the average bit error probability (BEP) and the outage probability over generalized fading channels. Specifically, we assume that the probability density function (PDF) of the instantaneous signal-to-noise ratio \(\zeta \) is given by the product of: power function, exponential function, and the modified Bessel function of the first kind, i.e., \(f_{\zeta }(\zeta )=\zeta ^{\lambda -1}exp\left( -a\zeta ^{\beta }\right) I_{v}\left( b\zeta ^{\beta }\right) \). Based on this PDF, we obtain a novel closed-form expression for the average BEP over such channels perturbed by an additive white generalized Gaussian noise (AWGGN). Note that other well-known noise types can be deduced from the AWGGN as special cases such as Gaussian noise, Laplacian noise, and impulsive noise. Furthermore, we obtain a novel closed-form expression for the outage probability. As an example of such channels, and without loss of generality, we analyze the performance of the average BEP and the outage probability over the \(\eta \)–\(\mu \) fading channels. Analytical results accompanied with Monte-Carlo simulations are provided to validate our analysis.