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In this paper, an artificial noise (AN) injection technique is incorporated in a free-space optical (FSO) communication system with the aim of enhancing the secrecy performance of the system. An intensity modulated direct detection (IM/DD) FSO link which is subjected to Malaga ( $\mathcal {M}$ ) distributed turbulence with pointing errors is considered in this paper. The performance of FSO systems is evaluated by deriving novel closed-form expressions for the secrecy outage probability (SOP), strictly positive secrecy capacity (SPSC), and throughput of the system. By formulating a constrained optimization problem, we discuss an optimal power allocation strategy for throughput maximization in the considered system. It is shown through the results that the proposed technique is very effective in improving the secrecy performance of FSO systems.

Power line communication (PLC) is an emerging field of communication that makes use of the existing power line infrastructure for the transmission of data and power. However, the presence of additive and multiplicative power line noises deteriorate the performance of a PLC system. Background and impulsive noises are the two main categories of additive noise, whereas channel gain accounts for the multiplicative noise. In this study, the authors propose coordinate interleaving (CI) technique and investigate its performance for a PLC system under the combined effect of Nakagami-m additive background noise and Rayleigh channel gain. They assume perfect channel state information at the transmitter and receiver of the PLC link. By interleaving the coordinates of the symbols sent over different channel realisations, CI results in significant improvement in the performance of a PLC system. Both the simulated and analytical results shown in this study reveal the effectiveness of the proposed technique in achieving better performance.

The α−κ−μ fading channel is a generalized fading model that incorporates the nonlinearity and nonhomogeneous scattering behavior of the propagation medium. In this paper, we investigate th...

Generalized Frequency Division Multiplexing (GFDM) is an attractive and recently proposed multicarrier modulation technique for the next generation wireless networks. However, GFDM suffers from self-interference problem due to the non-orthogonality of its subcarriers. In this paper, two novel schemes, each considering two-stage linear precoding, has been proposed that results in the improvement in the bit error rate (BER) performance of GFDM system with linear receivers. First schemes, considering linear MMSE receiver, results in achieving higher diversity gain in comparison to the GFDM system with one-stage precoding, while second scheme utilize two-stage precoding for the complete diagonalization of the modulation matrix. For second scheme, in addition to two-stage precoding, we consider signal space diversity (SSD) technique that results in achieving better performance. The validation of the improvement in the BER performance of GFDM system using proposed schemes has been shown through Monte Carlo simulations.