Joint RRH selection and beamforming in distributed antenna systems with energy harvesting

To reduce the transmission power while maintaining quality of service requirements of users, more remote radio heads (RRHs) should be active, and this in turn increases the circuit power in the distributed antenna systems with simultaneous wireless information and power transferring. Yet, the above procedures may lead to an unbalanced power consumption between transmission and circuit; therefore causes extra burden on the operators' power budget. To obtain a balanced transmission power and circuit power, this paper studies the system utility minimization problem in such a system via joint RRH selection and beamforming. The utility is formulated as the weighted sum of transmission power and circuit power. Since the formulated problem is NP-hard, a low complexity iterative algorithm is developed to achieve a near-optimal solution. The complexity of each iteration step is analyzed. Computer simulation results show the convergence of the proposed algorithm and the tradeoff between the transmission power and the circuit power.