A novel fading model for emerging wireless communication systems

Wireless communication systems have been recognized as one of the fastest-growing technologies in recent times. Wireless researchers look for viable solutions to meet higher data rates required by evolving applications. One solution is to use a dedicated ultra-high frequency (UHF) spectrum instead of the almost exhausted radio-frequency band. Emerging millimeter-wave (mmWave) band, terahertz (THz) band, femtocell, and wireless powered communication (WPC) systems are relatively new research areas, which can provide the needed solution to the rapidly growing need for higher data rates. However, there are unresolved challenges. A foremost challenge is the need for a suitable channel model to adequately characterize transmission environments. Channel modeling is a preliminary step for the successful design and deployment of any communication system; hence, channel modeling is the main focus of this thesis. This thesis presents detailed work on the newly-introduced Beaulieu-Xie (BX) distribution as a useful channel model, with extensive performance analyses. First, we analyze the BX fading model's second-order statistics for both single and diversity receptions using the probability density function (PDF) and characteristic function (CHF) methods, respectively. Our result provides insight into a communication system's dynamic performance operating on the BX fading model. Next, we carry out a robust performance analysis of correlated BX fading channels using bounds. Here, tractable analytical bit-error rate (BER) and outage probability (OP) expressions are derived using a newly-developed bounding technique that involves transforming correlated BX random variables (RVs) to correlated Gaussian RVs. Our results present insights into the primary factors affecting emerging communication systems' performance utilizing massive multiple-input and multiple-output technologies. Subsequently, we present performance analyses of the BX fading channels in the presence of interfering signals for diversity receptions of the maximal-ratio combining technique. Tractable expressions of the average BER and OP are derived and used to show the effect of interference on the communication systems' performance. The results provide insight into the performance of short-range communication systems where interference is prominent. Furthermore, we develop a new composite model, which we refer to as the shadowed Beaulieu-Xie (SBX). We derive the SBX's PDF, CHF, cumulative distribution function, and moment generating function in closed-form. Then, we carry out a detailed performance analysis of this new distribution and ultimately fit it to published experimental data obtained from fading measurements in 28 gigahertz outdoor mmWave channels. The goodness-of-fit demonstrates that our model yields far more accurate characterizations of new emerging wireless systems' communication environment than other existing unimodal and composite distributions. Finally, we apply the BX fading model to the performance analyses of WPC. We establish the validity of the BX fading model by the possible presence of multiple line-of-sight components in such communication environments. Here, we introduce two new nonlinear energy harvesters and fit them to measured data obtained from a communication system operating in a UHF band. Our fits are improved over those of existing nonlinear energy harvesters that apply the same set of measured data.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat

Performance bounds for diversity receptions over a new fading model with arbitrary branch correlation

The performance of a new (Beaulieu-Xie) fading model is analyzed using bounds. This recently proposed fading model can be used to describe both line-of-sight and non-line-of-sight components of a fading channel having different diversity orders. We consider the outage probability and error rate performance of maximal ratio combining, equal-gain combining, and selection combining over arbitrarily correlated Beaulieu-Xie fading channels. Closed-form expressions for upper and lower bounds to the outage probability and error rate are obtained, and it is shown that these bounds are asymptotically tight in the high signal-to-noise ratio regime. The analytical results are verified via Monte Carlo simulations. It is shown that the Beaulieu-Xie fading model can be more useful than the Ricean and Nakagami-m fading models in characterizing environments with both line-of-sight and multiple reflected specular components.Applied Science, Faculty ofEngineering, School of (Okanagan)ReviewedFacult

A new statistical channel model for emerging wireless communication systems

A new composite fading model is introduced. This shadowed Beaulieu-Xie model is developed to characterize wireless communication in an environment with an arbitrary number of line-ofsight and non-line-of-sight signals, in contrast to the existing Rayleigh, Ricean, generalized Ricean (i.e., κ − μ), and Nakagami-m models. The proposed model benefits from four parameters that characterize a wide range of fading conditions, unlike existing composite models such as the shadowed Ricean model, the two-wave with diffuse power model, and the fluctuating two-ray model. The proposed shadowed Beaulieu-Xie model is used here to characterize experimental data obtained from fading measurements in 28 GHz outdoor millimeter-wave channels, and it is found to describe the communication environment accurately. We conclude that the proposed composite fading model is particularly useful for characterizing emerging (millimeter-wave and terahertz) wireless communication systemsApplied Science, Faculty ofEngineering, School of (Okanagan)ReviewedFacultyGraduat

Asymptotically tight performance bounds for equal-gain combining over a new correlated fading channel

A recently proposed fading model which can be used to describe both line-of-sight and non-line-of-sight components of a fading channel is analyzed. The outage probability and error rate performance of equal-gain combining over arbitrary correlated Beaulieu-Xie fading channels is considered. Asymptoticallytight closed-form lower and upper bounds are derived and these analytical results are verified via Monte Carlo simulations.Applied Science, Faculty ofEngineering, School of (Okanagan)ReviewedFacult

Asymptotically tight performance bounds for selection diversity over Beaulieu-Xie fading channels with arbitrary correlation

A new (Beaulieu-Xie) fading model was recently proposed to describe line-of-sight and non-line-of-sight components in wireless channels. In this work, we consider both outage probability and error rate performance of selective combining over this new fading channel model with arbitrary channel correlation. Closed-form expressions are obtained for asymptotically tight upper and lower bounds. The analytical results are verified by Monte Carlo simulations.Applied Science, Faculty ofEngineering, School of (Okanagan)ReviewedFacult

Level crossing rate and average fade duration for the Beaulieu-Xie fading model

Level crossing rate (LCR) and average fade duration (AFD) of a new (Beaulieu-Xie) fading model are analyzed. The characteristic function method is used to derive the LCR for a diversity scheme using maximal ratio combining. The LCR and AFD of the Beaulieu-Xie fading model show improvement beyond the performance levels of the Ricean and Nakagami-m fading models.Applied Science, Faculty ofNon UBCEngineering, School of (Okanagan)ReviewedFacult