Multi-carrier Cell Structures with Angular Offset

Macrocellular networks with frequency reuse across cells suffer from high interference at the cell boundaries, resulting in a very uneven distribution of user throughput. In this paper a sector offset configuration for multi-carrier networks is proposed that can significantly improve the cell edge performance without reducing the frequency re-use factor. Simulations for UMTS HSDPA show that for a 3 sector base station transmitting on two carriers the proposed approach can increase the average user throughput by 38% and the throughput of the worst 5th percentile by 91%, with a small increase in the total number of handovers. In addition it is shown that the new configuration results in a reduced handover failure rate.