Adaptive Power Ratio Updating Algorithm in Soft Frequency Reuse Scheme

Soft fractional frequency reuse (SFR) is adopted as a main inter-cell interference coordination technique in the orthogonal frequency division multiplexing access(OFDMA) networks. In the paper, unlike the fixed power ratio configuration in other published papers, an adaptive power ratio updating in SFR scheme (APR-SFR) is explored. In each time slot, users measure the interference form other cells and report the signal to interference plus noise ratio to the associated cell. Then each base station updates the power ratio of SFR scheme adaptively and distributively based on the current interference situation to maximize the sum-rate of cell. The convergency characteristic of APR-SFR scheme is discussed and we prove APR-SFR is convergent with a proper updating ratio. Finally, we develop a LTE simulation platform with 7 cells to evaluate the proposed APR-SFR algorithm. The numerical results show that APR-SFR algorithm is flexible for different number of users and can get the better system performance than other algorithms.