Coordinated Caching and QoS-Aware Resource Allocation for Spectrum Sharing

5G cellular networks will heavily rely on the use of techniques that increase the spectral efficiency (SE) to meet the stringent capacity requirements of the envisioned services. To this end, the use of coordinated multi-point (CoMP) as an enabler of underlay spectrum sharing promises substantial SE gains. In this work, we propose novel low-complexity coordinated resource allocation methods based on standard linear precoding schemes that not only maximize the sum-SE and protect the primary users from harmful interference, but they also satisfy the quality-of-service demands of the mobile users. Furthermore, we devise coordinated caching strategies that create joint transmission (JT) opportunities, thus overcoming the mobile backhaul/fronthaul throughput and latency constraints associated with the application of this CoMP variant. Additionally, we present a family of caching schemes that outperform significantly the “de facto standard” least recently used (LRU) technique in terms of the achieved cache hit rate while presenting smaller computational complexity. Numerical simulations indicate that the proposed resource allocation methods perform close to their interference-unconstrained counterparts, illustrate that the considered caching strategies facilitate JT, highlight the performance gains of the presented caching schemes over LRU, and shed light on the effect of various parameters on the performance.