Stochastic Control of Event-Driven Feedback in Multi-Antenna Interference Channels
Spatial interference avoidance is a simple and effective way of mitigating interference in multi-antenna wireless networks. The deployment of this technique requires Channel-State Information (CSI) feedback from each receiver to all interferers, resulting in substantial network overhead. To address this issue, this paper proposes the method of distributive feedback control that intelligently allocates feedback bits over multiple feedback links and adapts feedback to channel dynamics. For symmetric channel distributions, it is optimal for each receiver to equally allocate the average sum-feedback rate for different feedback links, thereby decoupling their control. For low mobility and using the criterion of minimum sum-interference power, the optimal feedback-control policy is shown using stochastic optimization theory to exhibit opportunism.