Band-Distributed Channel-Aware Fractional Frequency Reuse in OFDMA Systems

Fractional frequency reuse (FFR) has been actively studied in order to reduce inter-cell interference, especially for cell edge users in current orthogonal frequency division multiple access systems. However, the best resource block (RB) allocation to the edge users is limited by conventional FFR, which has subbands consisting of contiguous RBs. In this paper, we propose a band-distributed FFR scheme that effectively employs channel quality information (CQI) by fully exploiting frequency diversity to mitigate this limitation. In this scheme, the entire system bandwidth is divided into two classes of sub-bands that comprise non-contiguous RBs. Our analysis shows that the proposed band-distributed FFR has better performance than the conventional FFR for various environments defined in IMT-advanced models. Moreover, the gain with our scheme increases as the coherent bandwidth (Be) increases.