Secrecy Capacity Over Log-normal Fading Channel with Diversity Combining Techniques

We consider a confidential communication through log-normal fading channel in which a single antenna transmitter communicates with a legitimate receiver in the presence of an eavesdropper. Employing maximal ratio combining (MRC) and equal gain combining (EGC) reception schemes at the legitimate receiver and eavesdropper, we find the closed-form expressions for the secrecy parameters, namely, the probability of non-zero secrecy capacity and the asymptotic secrecy capacity in terms of channel parameters such as correlation coefficient and the diversity order. We quantify the effect of diversity and antenna correlation and investigate, how the logarithmic standard deviation influences these effects of diversity and antenna correlation on the secrecy parameters. Moreover, as a result of obtaining closed-form expressions for the secrecy parameters, it is insightful to see how the channel parameters affect the security of lognormal fading channels.