Cache-induced hybrid CoMP in wireless video streaming networks

Mitigating inter-cell interference has become more crucial than before because there is a growing number of base stations (BSs) being placed into the network as a solution to increase the network capacity. To deal with the problem, cache-induced CoMP was recently proposed. It is based on caching a portion of media files, and taking benefits of sharing payload data (CoMP joint processing), but without the need of expensive backhaul. However, the on-off selection of CoMP transmission mode in the recent work [1] limits the efficient usage of cached data. It results in decreasing the chances to enjoy the CoMP joint processing, and hence causes the performance degradation. In this paper, we propose a cache-induced hybrid CoMP to cope with such limitation. By adding additional transmission mode, where some selected base stations are allowed to take advantage of CoMP joint processsing, more portions of cached data are made use of, and hence, CoMP utilization is increased. We optimize the beamforming vectors and the cache control, and simulation results demonstrate that our proposed hybrid CoMP scheme notably reduces the total power consumption of BSs to meet a certain QoS level.