In this study, the authors analyse the outage performance of the indoor relay‐assisted hybrid radio frequency (RF)/visible light communication (VLC) systems. They derive closed‐form expressions for the outage probability of the end‐to‐end signal‐to‐noise ratio. Then they obtain the optimal approximation parameter with optimising the outage probability using the differential evolution algorithm. Moreover, they analysed the average bit error rate (BER) performance of the hybrid RF/optical system using pulse position modulation method while assuming the timing error in synchronisation. Finally, they present some numerical results utilising the newly derived exact closed‐form expressions.

In this study, we analyze spectrum sensing performance by investigating amplify-and-forward (AF) based cooperative relaying in underlay cognitive radio networks with switch-and-examine combining (SEC) diversity technique in which the maximal ratio combining (MRC) and energy detector (ED) schemes are employed at the destination. First we derive closed-form expressions for both the probability density functions (PDFs) and the probability of detections (Pd) of the end-to-end signal-to-noise ratios (e2e SNRs) at the output of the switch-and-examine combiner under Rayleigh fading channel. Then the optimal detection threshold and switching threshold values with optimizing error rate (Pe) using the differential evolution algorithm (DEA) are obtained. Finally, we present some numerical results through the receiver operating characteristics (ROC) curves utilizing the newly derived closed-form expressions and we verify the numerical curves precisely match with the simulation results, validating our proposed theoretical analysis.

The authors evaluate theoutage probability, ergodic capacity, and symbol error rate (SER) performances of an amplify‐and‐forward relaying system equipped with a non‐ideal variable gain single relay with hardware (HW) distortions at both the transmitter and receiver sides with the derivations of the instantaneous end‐to‐end signal‐to‐noise‐and‐distortion ratios. More specifically, they analytically derive new algebraic expressions for the outage probability and ergodic capacity in the two‐way relaying system over the Nakagami‐ m fading environments. They further derive new closed‐form expressions for the asymptotic outage probability to analyse the performance in the high signal‐to‐noise regime. The derived statistics, along with the transmitter–relay–receiver channels are then used to obtain a closed‐form expression of the approximate and upper bound ergodic capacity. Finally, they investigate the generic mathematical expressions utilising the average and asymptotic SER, valid for several types of modulation schemes operating over the Nakagami‐ m fading. Monte Carlo simulations and numerical examples are provided to quantify the validity of the derived analytical expressions. The authors' results highlight the effect of HW impairments in the two‐way relaying system over the Nakagami‐ m fading channels and reveal the impact of the level of HW impairments, data rates, modulation types, and shaping parameters on the overall system performance.