Resource Allocation Strategy using optimal power control for mitigating two-tier interference in heterogeneous networks

Heterogeneous networks (Hetnets) consisting of Macro-cells and Small-cells (e.g. Femto-, Metro-, Pico-cell) are capable of extending cellular coverage and increasing capacity, while Fractional Frequency Reuse (FFR) scheme has been proposed. This scheme is most likely used for upcoming and future cellular systems especially in cellular OFDM networks (ex. LTE, Wimax). In Hetnets or two-tier networks of Macro-cells layered with Small-cells, the resource allocation will be sharing the same licensed frequency spectrum. In this paper, a simple resource allocation strategies along with power coordination scheme for the two-tier Macro/Femto is proposed that allows Femto-cells to coordinate and allocate more resources frequency allocation by using fractional frequency approach. The adaptive power allocation is also adopted. This strategy is analyzed in a multi-cell systems with coexistence of Macro-cells. Analytical and simulation results show that our simple resource allocation strategies are able to reduce inter-tier interferences and to offer an improvement of coverage probability and edge user SINR in the two-tier environment networks.