On the Capacity Performance of Hybrid FSO/RF System With Adaptive Combining Over Generalized Distributions

IEEE Photonics Journal

Swaminathan R¹  Narendra Vishwakarma¹ 

[1] Department of Electrical Engineering, Indian Institute of Technology, Simrol, MP, India;

关键词: Adaptive combining;    direct detection;    free space optics (FSO);    heterodyne detection;    κ–μ distribution;    Malaga distribution;   

DOI  :  10.1109/JPHOT.2021.3135115

来源: DOAJ

【 摘 要 】

This paper investigates the ergodic capacity performance of hybrid free space optics (FSO)/ radio frequency (RF) system by employing an adaptive-combining-based switching scheme. In the adaptive combining scheme, the FSO and RF links are combined using the maximal-ratio combining (MRC) at the output, when the instantaneous signal-to-noise ratio (SNR) of the FSO link drops below a predefined threshold SNR value. The FSO link experiences the atmospheric turbulence, which is modeled using the generalized Malaga distribution, non-zero boresight misalignment or pointing errors, and atmospheric attenuation, under two types of detection techniques, i.e. heterodyne detection (HD) and intensity modulation/direct detection (IM/DD). Similarly, the fading of the RF link is characterized using the generalized $\kappa$–$\mu$ distribution. In particular, we derive the probability density function (PDF) of the instantaneous SNR of the adaptive combining scheme. Capitalizing on the SNR statistics, we obtain the unified closed-form ergodic capacity expressions for the adaptive-combining-based hybrid FSO/RF system. In addition, the asymptotic expressions for the ergodic capacity of the system at the high-SNR region are presented. All the derived analytical expressions are validated by using Monte-Carlo simulations. Numerical results and discussions are provided to compare the ergodic capacity performance of the adaptive-combining-based hybrid FSO/RF system with the existing system models such as single-link FSO, MRC-based hybrid FSO/RF, and hard-switching-based hybrid FSO/RF systems.

【 授权许可】

Unknown