In the rapid development of wireless communications, femtocells provide tremendous improvement in coverage and quality of service for users. Macro-femto based networks are envisioned to be the de-facto solution for providing ultra-high speed communications in next-generation mobile wireless networks. This paper studies two-tier macro-femto networks and proposes a collection of novel technologies to address the interference problems. First, a novel user association scheme is proposed that aims to optimize the load among femto base stations (FBSs). Second, a near-optimal ergodic search algorithm is proposed to regulate the power consumption at macro base stations (MBSs) and improve energy efficiency. Third, a channel access mechanism is proposed for FBSs that aims to minimize inter-tier interference. For the proposed system, CDF of SINR is derived and used for performance investigation. Simulation results show that the proposed system can significantly outperform a popular, conventional cognitive radio-based system for all the considered simulation scenarios.

在无线通信的飞速发展中，毫微微小区为用户提供了覆盖范围和服务质量的巨大提升。基于宏毫微微的网络被设想为在下一代移动无线网络中提供超高速通信的事实上的解决方案。本文研究了两层宏毫微微网络，并提出了一系列新技术来解决干扰问题。首先，提出了一种新的用户关联方案，旨在优化毫微微基站（FBS）之间的负载。其次，提出了一种近乎最优的遍历搜索算法来调节宏基站（MBS）的功耗并提高能源效率。第三，针对 FBS 提出了一种旨在最小化层间干扰的信道接入机制。对于建议的系统，SINR 的 CDF 被导出并用于性能调查。仿真结果表明，对于所有考虑的仿真场景，所提出的系统可以显着优于流行的、传统的基于认知无线电的系统。