Research On Optimization Of Mode Three Ineterference In LTE Networks

The interference problem in the GSM system is mainly solved by frequency planning. CDMA technology is used in WCDMA system. It is a self interference system. Objectively speaking, CDMA technology has different degrees of pilot pollution and near far effect and so on. The source of the interference signal is the present district and all adjacent areas. Interference can be alleviated by soft switching mechanism. LTE system uses the OFDM technology. The channel is divided into several orthogonal sub channels. The high-speed data signal is converted into parallel low-speed data streams. The low speed sub stream is modulated to transmit on each sub channel. At the receiving end, the orthogonal signal is separated by the correlative technology. This can reduce the mutual interference between sub channels, and thus reduce the interference within the cell. The LTE network is mainly affected by the interference of adjacent cells. LTE uses the same frequency network. All cells within the system coverage area can use the same frequency band to provide services for the users within the community. So the spectrum efficiency is high. But adjacent cells use the same spectrum resources at the junction of the cell. This will cause strong inter cell interference. LTE network has special mode three interference. It is inevitable to become a typical "adjacent area interference system".The control of network interference is the key point of LTE network optimization. The main realization way is to optimize the network structure and the reasonable use of the network system function. When LTE uses the exiting mechanism of 3G or 2G for total station deployment, the original network structure has certain overlapping coverage. This is beneficial for soft switching in WCDMA. However, due to the hard switching in LTE, overlap area is too large. This will affect the adjacent cell and cause the reduction of SINR. The performance of the LTE network is mainly determined by the signal and interference noise ratio SINR. The overlapping coverage of the cells will increase the difficulty of PCI planning. This will cause mode three interference. It will seriously affect the user data throughput rate. Thereby this will affect the network capacity and reduce user perception. As a result, the LTE system has a higher requirement for the control of the coverage. On the basis of meeting the switching requirements, the overlapping coverage and avoiding over coverage should be minimized. This puts forward higher requirements on site selection, layout and the day antenna parameters. The main line of this paper is to optimize the SINR value. On the basis of this, this paper introduces the influence of weak coverage, PCI mode three interference, overlapping coverage and network topology structure on SINR value. This paper focuses on the PCI mode three interference, overlapping coverage. Methods to solve the PCI mode three interference have been explored. On the basis of a reasonable network structure, this paper uses the base station antenna system optimization and parameter optimization to solve the PCI mode three interference. At the same time, with the development of communication technology, the introduction of cell merging technology provides a new way to solve the PCI module three interference in the complex wireless environment.