Abstract: The dense deployment and overlapping coverage of femtocells in LTE will result in strong interferences between them. For femtocell downlink interferences, this paper proposes a power control algorithm based on the path loss. The algorithm uses the subordinate users’ path losses and the non-subordinate users’ path losses as bases to set the initial transmitting power of each femtocell. Each user calculates its SINR, maps it to a Channel Quality Indication （CQI） and then sends it to the user’s femtocell to adjust the transmitting power. The algorithm fully considers two cases of self-transmitting power shortage and outside interference. The simulation results indicate that the algorithm gives a very good control of users’ SINRs, and improves the users’ throughputs at the same time.

Key words: femtocell, power control, path loss, feedback, Signal to Interference Plus Noise Ratio（SINR）

摘要： 家庭基站在LTE中的密集部署，重叠覆盖会在家庭基站间造成较强的干扰。针对家庭基站的下行干扰，提出了一种基于路损的功率控制算法。该算法以下属用户的路损和相邻基站的非下属用户最小路损作为设定基站初始发射功率的依据，用户计算各自的信干噪比（SINR），并将信干噪比映射成信道质量指示（CQI）发送给家庭基站，各基站根据反馈信息调整自身发射功率，充分考虑到了自身发射功率不足和外界干扰两种情况。仿真结果表明，该算法很好地控制了用户的SINR，同时有效提高了家庭基站用户的吞吐量。

关键词: 家庭基站, 功率控制, 路损, 反馈, 信干噪比