A Novel Energy Efficient Scheme With a Finite-Rate Feedback Channel

In this letter, we propose an energy efficient communication scheme with a limited feedback rate for Rayleigh fading channels. First, we employ the available feedback words to quantize the channel-to-noise ratio (CNR) range and divide it into different regions. Then, we formulate the average energy efficiency (EE) for a given number of CNR regions using a fixed power and rate in each region. After that, we propose an offline optimization algorithm to compute the energy efficient CNR thresholds of each region and the associated transmission powers that maximize the EE. Finally, we evaluate the proposed scheme through simulations, by comparing the EE performance and effective achievable capacity against the case of perfect-CSI.