Shadowed Rayleigh Fading Research Articles

Outage Performance of UAV-Assisted Relaying Systems With RF Energy Harvesting

In this letter, we propose an UAV-based relaying system with energy harvesting functionality. In particular, we assume that this system is operated in urban communication environments, where the channel between the UAV and the land destination is modeled as shadowed-Rician fading or shadowed-Rayleigh fading. Based on this setting, outage probability analysis for different urban environment parameters is derived. Finally, Monte Carlo simulations are conducted to verify the accuracy of our analytical results.

Optimization of relay placement and power allocation for decode-and-forward cooperative relaying over correlated shadowed fading channels

In this paper, we investigate the relay placement and power allocation for decode-and-forward (DF) cooperative relaying over correlated lognormal shadowed Rayleigh fading channels. Assuming that maximum-ratio combining is performed at the destination, we first derive an upper bound of symbol error rate (SER) with M-phase-shift keying (PSK) modulation. Then, three optimization problems are formulated to minimize the obtained SER upper bound, namely optimal relay placement with fixed power allocation, optimal power allocation with fixed relay location, and joint optimization of relay placement and power allocation. It is shown by the analytical results that the correlation coefficients and the standard deviations of shadowing have significant impacts on the optimal relay placement and power allocation. The simulation results validate our analysis and show that the SER upper bound is asymptotically tight in the high signal-to-noise ratio (SNR) regime.

Outage Probability of MRC Diversity over Correlated Shadowed Fading Channels

In this letter, the outage probability of an L-branch Maximal Ratio Combining (MRC) diversity system is evaluated under non-identical correlated lognormal shadowed Rayleigh fading channels by extending the Moment Generation Function (MGF) method to approximate the output signal-to-noise ratio (SNR) by a new lognormal random variable, whose cumulative distribution function (cdf) is obtained by numerically solving for its mean and standard deviation. This cdf is then utilized to obtain the outage probability at a specific threshold. Extensive Monte Carlo simulations verify that the proposed approach is an accurate and efficient method to evaluate the desired outage probability, which would greatly facilitate the design and analysis of such systems.

Asymptotic Performance Analysis of STBCs from Coordinate Interleaved Orthogonal Designs in Shadowed Rayleigh Fading Channels

Asymptotic Performance Analysis of STBCs from Coordinate Interleaved Orthogonal Designs in Shadowed Rayleigh Fading Channels

Non Cooperative Space-Time Communication for Energy Efficiency in Sensor Networks

Space-time coded cooperative transmission has been proposed as a means to prolong the battery lifetime of conventional single-antenna energy-constrained wireless sensor nodes. However, newly proposed smart-antenna sensor prototypes enable the existence of more than one antenna within a single-radio transceiver architecture. Exploiting such capability, this paper proposes simple non-cooperative space-time techniques for single-RF switched-antenna systems that reduce significantly both the transmission and the circuit energy consumption. The energy savings of the suggested schemes are shown not only against conventional SISO systems, but also against cooperative diversity schemes in Rayleigh and log-normal shadowed Rayleigh fading channels with distance-based path loss.

Novel partial decision combining schemes for Rayleigh fading

ABSTRACTNew combining schemes for partial decisions using one‐bit and two‐bit information of the received samples are derived for Rayleigh fading channels. Compared with previous partial decision combining schemes, these new schemes have either better performances or simpler structures, or both. Simulation results show that some of the new schemes can achieve considerable performance gains over the conventional partial decision combiner in Rayleigh fading or log‐normal shadowed Rayleigh fading, whereas their structures are much simpler than the conventional partial decision combiner. This confirms the advantages of the newly designed combining schemes. Copyright © 2011 John Wiley & Sons, Ltd.

Performance analysis of a multicell DS-CDMA system with base station diversity

The performance of a multicell DS-CDMA cellular system with base station diversity is studied taking into consideration the effects of imperfect power control, multipath fading, shadowing and the dependence of propagation losses to a different base station from a mobile user. It is assumed that a mobile user is connected to the base station that provides the least attenuation among a set of closest uniformly correlated base stations. Analytical expressions are derived for the average probability of error of binary phase shift keying modulated signals for both the reverse link and the forward link. The channel is assumed to undergo correlated lognormal shadowed Rayleigh fading. Analytical results show that base station diversity significantly improves system performance.

Performance gain of S-macrodiversity system in log-normal shadowed Rayleigh fading channel

The authors offer an exact analysis for cochannel interference of a macrodiversity cellular system, called S-macrodiversity, where the branch selection is based on the local mean average signal power. In the past, most studies on macrodiversity have only included the shadowing effect. The authors' model includes both log-normal shadowing and Rayleigh fading.