Energy-efficient radio resource management in a HetNet downlink system with JT CoMP

With the booming data traffic in mobile networks, the energy consumption caused by the information and communications technology (ICT) industry has dramatically increased in the last decade. Therefore, design of energy-efficient technologies for communication systems has become a big issue. In this paper, we discuss the energy efficiency of a heterogeneous network (HetNet) downlink system. Joint transmission coordinated multipoint (CoMP) scheme is considered to combat with intercell interference. We propose a formulation to model a radio resource allocation (RRM) problem for the purpose of improving system energy efficiency. Under a comprehensive consideration, the RRM problem is constrained by transmit power of each antenna, capacity of backhaul links and a given QoS requirement. Since it is NP hard, the problem is simplified into an individual scheduling problem with known power allocation, combined with a power allocation problem with the obtained scheduling result. For the scheduling problem, we propose a heuristic algorithm based on the cross entropy (CE) method, and for the power allocation, we use a KKT-based method to approach the solution. Extensive simulation are conducted to validate the effectiveness and the efficiency of proposed algorithms.