Performance analysis of soft frequency reuse schemes for a multi-cell LTE-advanced system with carrier aggregation

Carrier aggregation is one of the promising features that expands the bandwidth of the Long Term Evolution-Advanced (LTE-A) system through aggregating multiple carriers to support high data rate up to 1 Gbit/s. When considering a multi-cell scenario, an appropriate resource allocation method that takes the inter-cell interference into account should be used. We investigate different soft frequency reuse (SFR) schemes and address an important issue which is how they should be applied in the presence of multiple carriers. Particularly, we propose two novel methods for performing the resource partitioning process: Local partitioning (LP) that divides each carrier individually between cell-center and cell-edge users, and Global partitioning (GP) in which dividing is at the level of the aggregate bandwidth. Simulation results demonstrate that the LP method performs better when most of users are LTE-A-capable terminals, whereas if the majority is for the legacy LTE Release 8 terminals then the GP method is advantageous. Furthermore, we show that using the transportation problem based resource allocation is a simple and yet flexible method that can be tuned to match the investigated SFR schemes and the proposed LP and GP resource partitioning methods.