A Proposal for Radio Resource Allocation of TDM Inter-Cell Interference Coordination to Heterogeneous Networks with Pico Cells in LTE-Advanced

This paper proposes an actual down link radio resource allocation scheme at pico base stations (PBS) in time domain multiplexing - inter-cell interference coordination (TDM-ICIC). Since TDM-ICIC is useful for a heterogeneous network coexisting with macro BSs (MBS) and PBSs, considerable research has been conducted on TDM-ICIC. However, previous studies have not explored actual resource allocation, but have instead focused on theoretical capacity clarification. In the proposed method, user equipment (UE) attached to a PBS is classified into two groups: one is defined as the "A-PUE" and the other as the "CRE-UE". The A-PUE is a UE which is always attached to the PBS. The CRE-UE becomes attached to the PBS through the application of cell range expansion (CRE). In the proposed method, UE prioritization based on the UE classification takes precedence over proportional fairness scheduling (PFS). The UE prioritization depends on the interference condition due to the transmission condition at the MBS. System level simulations demonstrate two reasonable candidates in resource allocation when the MBS mutes the signal. One is based on PFS and is an effective approach for improving the average user throughput in each UE group compared to that without the TDM-ICIC. The other is prioritized resource allocation for the CRE-UE, which can correct the imbalance in the average user throughput between two groups. By applying the prioritized resource allocation, the imbalance in the average user throughput decreases from more than 200% to 25%.