Expected rate of slow-fading channel with partial CSIT under computational and transmit power constraints

In this paper, we evaluate the expected rate with quantized feedback over a fading channel with both transmit and computational power constraints. We derive the optimal quantization scheme which can achieve the maximum expected rate in two different scenarios. First, for systems with a short-term power constraint, we derive an algorithm to find the optimum quantization schemes with bursty transmission. Second, for systems with a long-term power constraint, we prove that no explicit bursty transmission is required. We also propose a two-step power allocation method, based on the traditional waterfilling followed by a water adjustment step, which achieves the maximum expected rate. We quantify the gain that the proposed algorithms can achieve for different quantization levels.