Energy-Efficient Design MIMO Heterogeneous Networks with WB

As future networks aim to meet the ever-increasing
requirements of high data rate applications, dense and heterogeneous
networks (HetNets) will be deployed to provide better
coverage and throughput. Besides the important implications for
energy consumption, the trend towards densification calls for
more and more wireless links to forward a massive backhaul
traffic into the core network. It is critically important to take
into account the presence of a wireless backhaul for the energyefficient
design of HetNets. In this paper, we provide a general
framework to analyze the energy efficiency of a two-tier MIMO
heterogeneous network with wireless backhaul in the presence
of both uplink and downlink transmissions. We find that under
spatial multiplexing the energy efficiency of a HetNet is sensitive
to the network load, and it should be taken into account when
controlling the number of users served by each base station.
We show that a two-tier HetNet with wireless backhaul can
be significantly more energy efficient than a one-tier cellular
network. However, this requires the bandwidth division between
radio access links and wireless backhaul to be optimally designed
according to the load conditions.