Partial Secrecy Analysis in Wireless Systems: Diversity-Enhanced PLS Over Generalized Fading Channels

Securing information in future mobile networks is particularly challenging for deviceswith limited computational resources. In such contexts, physical layer security (PLS) offers a promisingalternative by exploiting the inherent randomness of wireless channels. When full secrecy cannot beguaranteed, the partial secrecy regime provides a realistic and effective approach to system design. Thisstudy investigates the partial secrecy performance of wireless systems operating over the recently introducedgeneralized multicluster fluctuating two-ray (MFTR) fading model. This model is highly regarded forits adaptability in representing a broad range of propagation environments and includes various classicalfading models as exceptional cases. We consider a secure communication setup involving a transmitter(A), an intended receiver (B), and an eavesdropper (E). Inspired by previous work showing the benefitsand simplicity of diversity schemes for improving PLS, we assume that both B and E are equipped withantenna arrays and apply maximal ratio combining (MRC). The model also considers independently but notidentically distributed (i.n.i.d.) fading conditions on the A → B and A → E links. We derive exact andclosed-form approximate expressions for three central metrics in partial secrecy theory: generalized secrecyoutage probability (GSOP), average fractional equivocation (AFE), and average information leakage rate(AILR). Unlike previous approaches based on simpler fading models, the proposed expressions maintain aconstant computational complexity, irrespective of the number of diversity branches, and are compatible withstandard mathematical tools. Validation via Monte Carlo simulations confirms the accuracy of the derivedexpressions and highlights the impact of key system parameters on secrecy performance. The flexible MFTRframework enables assessment across varied fading conditions. In particular, increasing the number of MRCbranches at B improves the GSOP diversity order and alters PLS behavior based on the fading characteristicsof the A → E link.