The Research Of Interference Coodination Technology And Its Application In LTE-A System

With the third mobile cellular network (3G) is formally applied in the world and the end of standardization of Long Term Evolution (LTE) wireless network, the fourth generation wireless network (LTE-Advanced) has been in the important period of standardization. Some significant characteristics in LTE-Advanced are wide-band, all IP-based, seamless, self- organization, self-optimization, self-configuration and so on. Among of these, broadband as the most important feature of LTE-Advanced require higher system data transmission rate and higher spectrum efficiency. Downlink peak rate is 1Gbit/s and uplink peak rate is 500Mbit/s. downlink peak spectral efficiency is 30Mbps/HZ and uplink peak spectral efficiency is 15Mbps/HZ.In order to meet the requirements of system data transmission rate and spectrum efficiency, key technologies of wireless transmission are adopted in LTE-Advanced, named orthogonal frequency division multiplexing (OFDM) and the design of frequency reuse factor=1. LTE-Advanced system use OFDM as a multi-carrier transmission technology, which easily enables cell frequency reuse factor is 1, In other words, each cell is able to use all of the frequency of the system. But serious Inter-cell interference occurs in the OFDM system. If LTE-Advanced system does not have other Inter-cell interference mitigation technologies, the system will face serious inter-cell interference.Inter-cell interference coordination technology researched in this paper is to mitigate or avoid the Inter-cell interference in the LTE-Advanced system. Many kind of Inter-cell interference coordination technologies have been proposed by many communication equipment companies. Among of these, soft frequency reuse (SFR) scheme which proposed by Huawei is very popular in this research area. First of all, the soft frequency reuse scheme is thoroughly studied in this paper and a theoretical model is to describe the SFR scheme, also the validation of this model is testified by the performance simulation. This theoretical model also reveal the relationship of three performance adjust factors and system performance. Furthermore, a combination of load balance technology and soft frequency reuse scheme is proposed in this paper. The new scheme integrates the merits of load balance technology and soft frequency reuse scheme. The new scheme can achieve the target of system load balance; meanwhile, it controls Inter-cell interference under a limit. In the end of paper, results of performance simulation testify the advantages of this new scheme.