This paper studies the performance of multihop free-space optical (FSO) systems using the subcarrier binary phase-shift keying modulation (BPSK) over atmospheric turbulence channels. We propose a modified relaying strategy, termed amplify-decode-and-forward (ADF), realised by using avalanche photodiode (APD) receivers. The outage probability of the proposed system is analytically derived consid...

This paper presents a short-term wind turbine (WT) outage model based on the data collected from a wind farm supervisory control and data acquisition (SCADA) system. Neural networks (NNs) are used to establish prediction models of the WT condition parameters that are dependent on environmental conditions such as ambient temperature and wind speed. The prediction error distributions are discusse...

Wireless Relaying is a promising solution to overcome the channel impairments and provides high data rate coverage that appears for beyond 3G mobile communications. In this paper we present end to end BER performance of dual hop wireless communication systems equipped with multiple Decode and Forward relays over Rayleigh fading channel with the best relay selection. We compare the BER performan...

In this paper, we study the performance of the selection combining and switch and stay combining methods in secure cooperative device-to-device (D2D) communications underlying a cellular network where an untrusted amplify and forward relay helps D2D communications. In our model, we specifically consider the interference from the cellular system over the D2D pair and the interference from the D2...

Two major performance degrading factors in free space optical communication systems are rainfall and atmospheric turbulence. We study the outage probability and bit-error rate for free-space communication links with spatial diversity and Gaussian-Schell electromagnetism beams over the raining turbulence fading channels by double inverse Gaussian distribution proposed in this paper. Assuming int...

CDMA cellular networks support soft handover, which guarantees the continuity of wireless services and enhanced communication quality. Cellular networks support multimedia services under varied propagation environmental conditions. In this paper, we have shown the effect of characteristic parameters of the cellular environments on the soft handover performance. We consider path loss exponent, s...

In this letter, power allocation methods are devised for Amplify-and-Forward (AF) opportunistic relaying systems aiming at minimizing the outage probability. First, we extend the result on outage probability in [8] and develop an approximate expression to simplify the power allocation problem. A corresponding optimization problem is constructed and proved to be convex. Then an iterative numeric...

In this paper, we consider an integrated voice and data system over CDMA Slotted-ALOHA (CDMA SALOHA). We investigate its performance when multi-code CDMA (MC-CDMA) is applied as a multi-rate scheme to support users which require transmission with different bit rates. Two different classes of data users are transmitted together with voice. Performance measurement is obtained in respect of throug...

Relaying has been proposed to support users suffering from high shadowing or high interference and therefore being not able to receive high data rates. With adaptive relaying, a higher Modulation and Coding Scheme (MCS) can be used in order to increase the feasible data rate. The investigation of relaying techniques widely has concentrated on information theoretical methods. Instead, this paper...

Abstract: Outage probabilities are important measures of the performance of wireless communication systems, but to obtain outage probabilities it is necessary to first determine detailed system parameters, followed by complicated calculations. When there are multiple candidates of diversity techniques applicable for a system, the diversity order can be used to roughly but quickly compare the te...