Optimal Power Allocation in MISO Cache-Aided Communication

The problem of cache-aided communication is studied for cellular networks with multi-user, with multiple-input and multiple output antennas, and finite range of signal-to-noise ratio. Users are assumed to have non-symmetric links, modeled by wideband fading channels. The ultimate goal is to design a joint power, rate, and cache allocation along with pre-fetching and fetching schemes to minimize the duration of communication in the delivery phase. This is formulated as a linear program, and a closed form solution is presented for some special range of parameters. In particular, the gain of MIMO coded caching is shown to be beyond trading between spatial diversity and accumulative cache size, specially in low SNR regime, where each user can be served at its own channel rate, rather than being compromised by the poorest user in the communication group.