Spatial Throughput Characterization of Cache-Enabled Cognitive Radio Networks with Interference Cancellation

This paper addresses the design of opportunistic spectrum access (OSA) in cognitive radio (CR) networks that incorporate caching capabilities, with a focus on enhancing performance through interference cancellation (IC). We introduce an OSA protocol that leverages IC to expand spectrum access opportunities for secondary transmitters (STs). Under this protocol, an ST can transmit either when it resides in a genuine spatial spectrum hole left unused by the primary system, or when such a hole is effectively synthesized at the primary receivers (PRs) by applying IC, aided by cached data as side information. To evaluate the proposed approach, we construct an analytical model grounded in stochastic geometry, assuming that both primary and secondary nodes follow homogeneous Poisson point process (HPPP) distributions. We derive explicit expressions for the transmission probabilities of both primary transmitters (PTs) and STs within this framework. Building on these results, we analyze the spatial distributions of active transmitters conditioned on a typical PR or secondary receiver (SR) situated at the origin. This enables us to quantify key performance metrics, including coverage probability and spatial throughput for both network tiers. Numerical simulations validate our theoretical findings and demonstrate that the proposed IC-assisted OSA scheme delivers marked improvements over traditional access strategies.