Two-Tier Cellular Networks: Enhanced Secondary Node Resource Allocation, Applied to LTE-A

The ability to accommodate the contrasting requirements of extended coverage, enhanced capacity and reduced deployment costs has led to the adoption of Two-Tier connectivity structures, in which secondary nodes connect users' terminals to base stations, as a promising design direction for contemporary cellular communications systems. This paper considers a Two-Tier Cellular Network employing fixed secondary nodes and introduces enhanced channel estimation and resource allocation procedures that exploit lower channel variation rates, along with the ability to use larger antenna arrays at these nodes to achieve substantial performance gains. Based on data measured from a live LTE-Advanced network, the expected average throughput gains when connecting a single secondary node varied between 10.2% and 65.0%. Furthermore, when emulating the deployment of five secondary nodes under the Round Robin, Best Channel Quality Index and Proportional Fair scheduling algorithms, one anticipates average throughput gains of 64.0%, 41.2% and 128.5%, respectively, while resource allocation fairness is expected to improve by 28.9%, 80.2% and 24.1%, respectively.