Cross-polarized complementary frequency allocation in femto-macro networks

The next-generation heterogeneous networks are expected to offer higher data-rate and better QoS to the customers by leveraging smaller cells like femtocells and making use of orthogonal frequency division multiple access (OFDMA). However, uncoordinated dense deployment of femtocells in a macrocell network pose unique challenges involving cross-tier interference and resource management which may lead to significant performance degradation in the system. As part of addressing these challenges, this paper proposes a Cross- Polarized Complementary Frequency Allocation (CPCFA) strategy which exploits frequency and polarization diversity to mitigate interference in two-tier femto-macro networks. This strategy combines the benefits of reverse frequency allocation (RFA) and orthogonal polarized transmission which is analyzed as a potential solution for maximizing spectral efficiency and minimizing interference in heterogeneous networks. The results of analytic and simulation studies prove that CPCFA increases the scope for an easily implementable, remarkable opportunity in the context of two-tier femto-macro network that can substantially increase the system capacity, area of interference-free femtocell exclusive region as well as the coverage probability without additional network complexities.