Block-Correlation-Based Outage Analysis for FAS-Assisted Wireless Powered Communication

Abstract

A fluid antenna system (FAS) can improve both energy harvesting and data transmission in wireless powered communication (WPC) by exploiting spatial diversity with a single RF chain. In this letter, we study the outage probability of a FAS-assisted WPC network under the port selection criterion that maximizes the product of the channel gains of the two links. Adopting the block-correlation (BC) decomposition fitted to the Jakes’ autocorrelation function, we derive a semi-analytical outage expression via nested Gauss–Chebyshev quadrature with singularity-removing variable substitutions. Numerical results under the exact Jakes’ correlation confirm the analytical predictions and show that exploiting both links in port selection yields much lower outage probabilities than single-link selection. Moreover, the advantage becomes more pronounced as the aperture increases, and for sufficiently large apertures it further increases with the number of ports. For the considered settings, significant diversity gains from increasing the number of ports are observed at $W=4\lambda $ .