Enhancing the Performance of Cluster-based Networks through Energy Efficient MISO Techniques

Network clustering has been proposed as an efficient approach for addressing the problems arising from the continually increasing network density. Beside the congestion relieving and the coverage extension, cluster-based networks provide considerable energy savings, improving the sustainability of low-power networks. It has been shown that the energy efficiency and the network reliability are further enhanced by allowing the devices within a cluster to establish a communication link to the infrastructure through more than one cluster-heads (CHs). The performance improvement due to the diversity gain is important, but it may come at the cost of additional complexity, since the CHs have to continuously estimate the channel state information (CSI) for each device requiring access grant. In this paper, we are presenting an alternative scheme, aiming at reducing the hardware complexity by avoiding the CSI estimations, while maintaining the benefits from the CH selection scheme. The benefits of such an approach can be clearly identified in case that CH-based network operate in composite fading environments, where multipath fading coexists with shadowing. In our case, this composite environment has been modeled by the K distribution. The presented theoretical analysis, which is validated via extensive computer simulations shows that the performance of the low-complexity scheme is comparable to the CSI-based one.