Interference Mitigation for Cognitive Femto Base Station Resource Management in Heterogeneous Networks

• Main Authors: Chang-jiang Tsai, 蔡長江
• Other Authors: Yung-fang chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/06520133461738427057

碩士 === 國立中央大學 === 通訊工程學系 === 102 === In this thesis, the problem for maximizing the system sum spectral efficiency in heterogeneous networks is considered. The major problem in heterogeneous networks is the cross-tier interference because the spectra is shared between the macro base station and femto base stations. In order to resolve the interference problem, we propose the resource allocation of femto base stations with the application of cognitive radio (CR) technique in order to maximize the spectral efficiency of all the system macro base station and femto base stations while simultaneously decrease the interference caused from femto base station to macro users. The proposed scheme comprises two steps: spectrum sensing and resource allocation. The femto base stations are capable of finding the available subcarriers using cognitive radio techniques. It can avoid the femto base station allocate the subcarrier which is unoccupied by near macro users in order to reduce the strong interference to macro users. After determining the subcarriers which is occupied by near macro users, the femto base stations further distinguish the qualified subcarriers according to the signal to interference plus noise ratio (SINR) to its serving femto users and the transmit power is allocated over the subcarriers by water-filling algorithm. Finally, simulation results also reveal that the proposed schemes outperform the existing algorithms.