On the Effect of Incorrect Channel Condition Information on Modified Switching Scheme of Hybrid FSO/RF System

Abstract

In hybrid free space optical/radio frequency (FSO/RF) communication, the optical link as well as the RF link is switched ON and/or OFF based on the feedback of the channel state information (CSI). However, feedback of full CSI is computationally complex and bandwidth inefficient. A bandwidth efficient form of channel state information which is referred to as Channel Condition Information (CCI) is used as a feedback to decide the modes of transmission/operation in accordance with the switching scheme that is used. Here, modified switching scheme is used, which has four operating modes. CCI is a combination of few bits containing information that is required to identify the mode of transmission of the hybrid FSO/RF system. Incorrect reception of CCI at the transmitter due to noise and fading in the feedback RF link may lead to an erroneous switching between modes of operation. These errors in the mode of transmission/operation lead to degradation in the system performance. In this paper, we have studied the impact of incorrect reception of CCI on the performance of the hybrid FSO/RF system under strong turbulence and fading conditions. The closed form expressions for outage probability and BER are derived.