Study On Femtocell Down Interference Restraint Algorithm

Fomtocell is a technology based on the indoor coverage of super tiny base station, which is known as Femtocell Base Station because of its unique allocation characteristics. As mobile communication develops towards broadband, increasingly more voice traffic and data traffic occur in indoor scenes, over40%of which are facing unsatisfactory indoor scenes coverage. Femtocell emerges as the times require and becomes a hot issue in this field because of its good practical applicability. Femtocell based on random distribution will cause interference to current mobile communication network and affect the function of the entire network if it is allocated in traditional Macrocell network. For this reason, it has high practical significance and value to explorer ways of improving function of entire system and enhancing utilization of frequency band by restraining interference caused by Femtocell allocation, which is exactly the issue this study mainly discusses.This study compares the characteristics of current indoor coverage technologies with that of Femotocell, analyzes the two-tier network scene composed of Femtocell and traditional Macrocell network and further studies cross-layer and co-layer interference scenes in wireless networks. To deal with this scene, this study aims to put forward a frequency allocation algorithm based on Femtocell and Macrocell, which divides frequency resource into three sections, namely Macrocell exclusive frequency band、Femtocell exclusive frequency band and frequency band. This algorithm allocates frequency resource, effectively reduces cross-layer interference and increases frequency band usage of the system through measuring SINR.This study has proposed an algorithm based on RS sequence pseudo-random channel selection to cope with that that algorithm can not fix neither co-layer interference between Femtocells nor cross-layer interference possibly occurs within reuse frequency band, which enables Femtocell to randomly choose channels in terms of time dimension. It randomizes down interference that Femtocell brings to Macrocell, equivalently sharing the influence of interference equally which can effectively restrain cross-layer interference within frequency reuse. In addition, RS sequence is a Pseudo-Random Sequence. As a result, it can effectively restrain co-layer interference between Femtocells.Simulation result suggests that compared with traditional Femtocell down interference mitigation algorithm, the algorithm this study has put forward can effectively improve network functions including interference mitigation and overall throughput.