Improved Frequency Reuse Schemes with Horizontal and Vertical Sector Offset with Static Beam-forming for LTE

Macrocellular networks with frequency reuse across sectors of the same eNodeB and neighboring eNodeBs suffer from high interference at the cell boundaries. Recently, it has been shown that for multi-carrier UMTS networks a horizontal offset configuration for the second carrier can mitigate this problem and significantly increase network performance at the cost of an increased number of handovers. This new NodeB configuration has also been extended to the vertical dimension, achieving a higher frequency reuse at the cost again of an increased number of handovers. In this paper, we building upon our previous research on horizontal sector offset for LTE, and extend the vertical sector offset configuration to eNodeBs, which through a novel cell-specific reference signal transmission configuration allow deploying offset antennas without increasing the number of sectors per eNodeB. In this way, the number of handovers does not significantly increase compared to the UMTS case. Simulations for LTE show that the proposed horizontal and vertical sector offset configuration can increase the average UE throughput and cell-edge UE throughput up to 84% and 250%, respectively, compared with traditional approaches.