Two-Timescale Optimization Approach for Caching, Computing, and Communication in MIMO-OFDM Wireless Networks with and Without RISs

This paper explores the joint optimization of caching, computing, and communication (3 C) in multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) wireless networks. It also incorporates the use of reconfigurable intelligent surfaces (RISs) to enhance communication performance. Given the different timescales for updating various resource allocations, we propose a two-timescale joint 3C optimization approach aimed at minimizing network latency. In this approach, task offloading, computing power allocation, precoding, and RIS optimization occur on the small timescale, while caching is updated on the large timescale. Our simulation results demonstrate that this approach effectively reduces network latency and outperforms the reference schemes.