Performance Analysis of Hard-Switching Based Hybrid FSO/RF System over Turbulence Channels

Abstract

The hybrid system of free space optic (FSO) and radio frequency (RF) has come forth as alternative good solution for increasing demand for high data rates in wireless communication networks. In this paper, wireless networks with hard-switching between FSO and RF link are analyzed, assuming that at a certain time point either one of the two links are active, with FSO link having higher priority. As the signal-to-noise ratio (SNR) of FSO link falls below a certain selected threshold, the RF link is activated. In this work, it is assumed that the FSO link follows Gamma-Gamma fading due to the atmospheric turbulence effect whereas RF link experiences Rayleigh fading. To analyze the proposed hybrid model, analytical expressions are derived for the outage probability, bit error rate and ergodic capacity. A numerical comparison is also done between the performances of the proposed hybrid FSO/RF model and the single FSO model.

Performance evaluation of dual backhaul links RF/FSO for small cells of 5G cellular system

“…The mix system of FSO and RF consider one of solutions aimed to increase the desire of high speed in wireless communication. Several study [10], [11] analyzed a hard-switching between FSO and RF link. The authors assumed that the FSO link follows Gamma-Gamma fading because of the effect of atmospheric turbulence.…”

“…The 𝑥 𝑅𝑆 (𝑡 1 ) indicates the RF signal transmitted from the source RS. When the SIM scheme [10], [19] is employed in the relay, the retransmitted optical signal at the RS will be:…”

“…⁄ 𝛾 𝑡ℎ,𝑅𝐹 0 (17) While the link between the RS and the users of FSO is assumed to experience the gamma-gamma fading distribution with the PDF given in [10], [19] as the ( 18)…”

“…where the 𝛾 2 ̅ is the average of SNR of FSO link and the 𝐾 (𝑎) (0) is the Bessel function of the second kind of order a, and the 𝛼, 𝛽 is the atmospheric turbulence of FSO link conditions which are defined in ( 5) and ( 6) of [10], [21], [25], and as in (19) and (20).…”

Prediction of Received Optical Power for Switching Hybrid FSO/RF System

“…Measurement of wind speed in the process of analysis of the availability of FSO systems is important, especially in terms of identifying the occurrence of optical turbulence in the vicinity of the transmission path between the FSO transmitter and the receiver. The main adverse effects of atmospheric turbulence on the optical signal are scintillation [16].…”