Time hysteresis-switching algorithm assisted dual-hop relaying for hybrid FSO/RF system

Abstract

Abstract A less-complex and efficient time-hysteresis (TH)-switching algorithm assisted hybrid free-space optics (FSO)/millimeter wave (mm)-radio frequency (RF) system is presented in the paper. For improving the long-haul communication efficiency we blend a decode-and-forward (DF) relaying scheme in the proposed hybrid FSO/RF system along with maximal-ratio-combining (MRC) at receiver end for signal reconstruction.TH-switching is utilized for link transient between FSO and RF links. The exact closed-form expressions for average symbol-error-rate (ASER) and outage-probability (OP) have been derived for the performance evaluation of the system. We also present asymptotic-analysis of the ASER and OP with lower computational-complexity of the proposed system and obtain the diversity-order. To achieve target-SER value for the proposed TH-switching, the optimum-threshold-SNR value has been obtained numerically. It is observed that the proposed switching technique assisted selective-DF-relaying scheme based hybrid system along with MRC outperforms a cooperative single-FSO system as well as single-hop (SH) switching-assisted hybrid system on account of diversity as well as switching technique benefits. The proposed hybrid system achieves SER of 10− 7 in the lower SNR regimes.