Performance analysis of Dual-hop Multi-relaying System over Rayleigh plus Log-normal Fading Channel

Abstract:
Up-to-date the log-normal fading effect is still not fully studied for the relaying system because its underlying statistics generally does not lead to a closed-form expression. In this paper, we proposed an analytical frame work for the performance analysis of dual-hop multi-relaying over indoor Rayleigh plus log-normal (composite) fading channel, where the selected relaying link has end-to-end power constraint. Thus, we first derive a closed-form expression of outage probability under conditioned constraint that relaying end-to-end power has much larger signal-to-noise (SNR) level ( 1 chi ) relative to the targeted threshold (chiT ) ;chi >> chi T 1 , then investigate the bit-error-rate (BER) performance, with a variety of shadowing standard deviations. The closed-form expressions allow rapid calculation of system performances in terms of the shadowing standard deviation, relative end-to-end relaying SNR and a number of relay nodes. This was not possible previously. Numerical analyses, in comparison with the asymptotic results from accurate solutions with non-closed form, demonstrated that our proposed scheme provides a simple and efficient approach to evaluate the impact of the shadowing effect and thus analytical optimization and relaying output power margin becomes feasible in real system design applications. Keywords – Rayleigh fading, log-normal fading, dual-hop multi-relaying, outage probability, log-normal standard deviation.