Application-driven beamforming for video streaming in MISO interference networks

In this paper, we consider an application-driven beamforming control for video streaming in multi-antenna interference networks. The optimization objectives for video streaming are the application level performance metrics, namely the playback interruption cost and buffer overflow cost. Using heavy traffic approximation technique, we first derive the diffusion limit for the discrete time queueing system. Based on the diffusion limit, we then formulate an infinite horizon ergodic control problem to minimize the average power of the base stations subject to the constraints on the playback interruption costs and buffer overflow costs of the mobile users. To deal with the queue coupling challenge, we utilize the weak interference coupling property and derive a closed-form approximate value function of the associated optimality equation using perturbation analysis. Based on the closed- form approximate value function, we propose a low complexity queue-aware beamforming control algorithm, which is asymptotically optimal for sufficiently small cross-channel path gain. Finally, the proposed scheme is compared with various baselines through simulations and it is shown that significant performance gain can be achieved.