Energy Efficient Power Allocation for Carrier Aggregation in Heterogeneous Networks: Partial Feedback and Circuit Power Consumption

The energy-efficient power allocation for carrier aggregation (CA) in heterogeneous networks (HetNets) is studied in this paper. We assume that multiple component carriers belong to HetNets and, thus, inter-band CA is considered, where both full and partial feedback scenarios are investigated. For the latter, we consider quantized channel state information at the transmitter and the corresponding power allocation policies are derived. Next, we derive energy-efficient optimal power allocation policies by assuming circuit power consumption for the transmitter that account for the multiple radio frequency (RF) chains required to support massive inter-band CA. The resulting algorithms are then used in order to investigate the relation between optimal energy efficiency (EE) and design parameters such as the number of frequency bands, antennas and feedback allocation through controlling the quantized information. A greedy optimization algorithm is also introduced to jointly optimize the aforementioned parameters. By carrying out simulations, it is observed that the achievable EE gains for massive CA in HetNets is further limited by either the number of feedback bits or the increase in RF circuits power consumption.