Performance analysis of mixed Nakagami- m and Gamma–Gamma dual-hop FSO transmission systems

In this paper, we carry out a unified performance analysis of a dual-hop relay system over the asymmetric links composed of both radio-frequency (RF) and unified free-space optical (FSO) links under the effect of pointing errors. Both fixed and variable gain relay systems are studied. The RF link is modeled by the Nakagami-m fading channel and the FSO link by the Gamma-Gamma fading channel subject to both types of detection techniques (i.e., heterodyne detection and intensity modulation with direct detection). In particular, we derive new unified closed-form expressions for the cumulative distribution function, the probability density function, the moment generating function (MGF), and the moments of the end-to-end signal-to-noise ratio (SNR) of these systems in terms of the Meijer's G function. Based on these formulas, we offer exact closed-form expressions for the outage probability (OP), the higher order amount of fading, and the average bit error rate (BER) of a variety of binary modulations in terms of the Meijer's G function. Furthermore, an exact closed-form expression of the end-to-end ergodic capacity is derived in terms of the bivariate G function. Additionally, by using the asymptotic expansion of the Meijer's G function at the high-SNR regime, we derive new asymptotic results for the OP, the MGF, and the average BER in terms of simple elementary functions

Unified Performance Analysis of Mixed Line of Sight RF-FSO Fixed Gain Dual-Hop Transmission Systems

In this work, we carry out a unified performance analysis of a dual-hop fixed gain relay system over asymmetric links composed of both radio-frequency (RF) and unified free-space optics (FSO) under the effect of pointing errors. The RF link is modeled by the Nakagami-$m$ fading channel and the FSO link by the Gamma-Gamma fading channel subject to both types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)). In particular, we derive new unified closed-form expressions for the cumulative distribution function, the probability density function, the moment generation function, and the moments of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer's G function. Based on these formulas, we offer exact closed-form expressions for the outage probability, the higher-order amount of fading, and the average bit-error rate of a variety of binary modulations in terms of the Meijer's G function. Further, an exact closed-form expression for the end-to-end ergodic capacity for the Nakagami-$m$-unified FSO relay links is derived in terms of the bivariate G function. All the given results are verified via Computer-based Monte-Carlo simulations

Impact of Pointing Errors on the Performance of Mixed RF/FSO Dual-Hop Transmission Systems

In this work, the performance analysis of a dual-hop relay transmission system composed of asymmetric radio-frequency (RF)/free-space optical (FSO) links with pointing errors is presented. More specifically, we build on the system model presented in [1] to derive new exact closed-form expressions for the cumulative distribution function, probability density function, moment generating function, and moments of the end-to-end signal-to-noise ratio in terms of the Meijer's G function. We then capitalize on these results to offer new exact closed-form expressions for the higher-order amount of fading, average error rate for binary and M-ary modulation schemes, and the ergodic capacity, all in terms of Meijer's G functions. Our new analytical results were also verified via computer-based Monte-Carlo simulation results.Comment: 6 pages, 3 figure

“Articulating cognizance about what to hide what not":Insights into why and when ethical leadership regulates employee knowledge-hiding behaviors

Given the dearth of research examining the distinctions across various facets of employee knowledge-hiding (KH) behaviors, there is little known about why and when leadership negatively influences playing dumb and evasive hiding but positively influences rationalized hiding. The present study fills this void by hypothesizing that employee justice orientation (JO) acts as a mediator of the associations of ethical leadership (EL) with different facets of employee KH behaviors. We also propose employee conscientiousness moderates the relationship of EL with JO and the indirect relationships of ethical leadership with distinct variants of employee KH behaviors. The results based on time-lagged data from 387 employees provide support for the hypothesized relationships. Together, our research provides a more nuanced account of the influence of leadership on employee KH behaviors that can facilitate the development of more appropriate interventions to deal with the intricate problems related to employee KH behaviors

“Articulating cognizance about what to hide what not":Insights into why and when ethical leadership regulates employee knowledge-hiding behaviors

Given the dearth of research examining the distinctions across various facets of employee knowledge-hiding (KH) behaviors, there is little known about why and when leadership negatively influences playing dumb and evasive hiding but positively influences rationalized hiding. The present study fills this void by hypothesizing that employee justice orientation (JO) acts as a mediator of the associations of ethical leadership (EL) with different facets of employee KH behaviors. We also propose employee conscientiousness moderates the relationship of EL with JO and the indirect relationships of ethical leadership with distinct variants of employee KH behaviors. The results based on time-lagged data from 387 employees provide support for the hypothesized relationships. Together, our research provides a more nuanced account of the influence of leadership on employee KH behaviors that can facilitate the development of more appropriate interventions to deal with the intricate problems related to employee KH behaviors

Composite and Cascaded Generalized-K Fading Channel Modeling and Their Diversity and Performance Analysis

The introduction of new schemes that are based on the communication among nodes has motivated the use of composite fading models due to the fact that the nodes experience different multipath fading and shadowing statistics, which subsequently determines the required statistics for the performance analysis of different transceivers. The end-to-end signal-to-noise-ratio (SNR) statistics plays an essential role in the determination of the performance of cascaded digital communication systems. In this thesis, a closed-form expression for the probability density function (PDF) of the end-end SNR for independent but not necessarily identically distributed (i.n.i.d.) cascaded generalized-K (GK) composite fading channels is derived. The developed PDF expression in terms of the Meijer-G function allows the derivation of subsequent performance metrics, applicable to different modulation schemes, including outage probability, bit error rate for coherent as well as non-coherent systems, and average channel capacity that provides insights into the performance of a digital communication system operating in N cascaded GK composite fading environment. Another line of research that was motivated by the introduction of composite fading channels is the error performance. Error performance is one of the main performance measures and derivation of its closed-form expression has proved to be quite involved for certain systems. Hence, in this thesis, a unified closed-form expression, applicable to different binary modulation schemes, for the bit error rate of dual-branch selection diversity based systems undergoing i.n.i.d. GK fading is derived in terms of the extended generalized bivariate Meijer G-function

The Nexus of Ethical Leadership, Job Performance, and Turnover Intention: The Mediating Role of Job Satisfaction

This study aims to examine the impact of ethical leadership on employees’ job satisfaction, performance, and turnover intention. A conceptual framework is developed which clearly integrates job satisfaction as a mediating mechanism in explaining the nexus among ethical leadership, job performance, and turnover intention. This framework is then analysed employing data from a sample (n = 114) of tourist companies in Lahore, Pakistan. The results reveal that ethical leadership has positive effect on employees’ job satisfaction, performance and has negative effect on their turnover intentions. Further, job satisfaction positively mediates the effect of ethical leadership on employees’ job performance and turnover intentions. The findings recommend that the demonstration of ethical leadership behaviours by managers at workplace enhances employees’ job satisfaction and performance, and decreases the intention of employees to leave the job. The main narrative of this study encompasses the imperative role of ethical leadership in the workplace where it serves as a factor that enhances employees’ job satisfaction, performance, and decreases turnover intention. This research explicitly demonstrates that in Pakistani tourism sector, ethical leadership plays a vital role to achieve performance goals. Future research could analyse the said nexus in different sectors and cultures, and may also consider other measures of individual performance. The consideration of job satisfaction as mediating variable in probing the linkages among ethical leadership, job performance, and turnover intention in the context of the workplace in Pakistan and the analysing of this linkage is novel