| With the issuance of4G licenses, LTE system in our country is beginning to belarge-scale commercial used. Because the reuse factor of LTE system is one, so the result issame frequency networking. Therefore, the inter cell interference is a serious problem.Interference coordination scheme is mostly used to solve to the LTE-inter cell-interferenceproblem, but it has some shortcomings. In this dissertation, based on the analysis of the keytechnology of LTE system and the existing interference coordination scheme simulation test,we put forward a new user-classification-scheme according to the value of distance and SINR,and verify the effectiveness of the improved scheme by simulation. This dissertation mainlycompleted the following works:The two major scheme of interference coordination technology-SFR scheme and FFRscheme were analyzed in detail, and their advantages and disadvantages were pointed out.We introduce the two underlying core technology-OFDM technology and MIMOtechnology of LTE system, the two technologies is the key to the anti-interference ability ofLTE system. The LTE power control and distribution system are introduced, and points outtheir importance of anti-interference in LTE system. LTE system technology has importantsignificance for the improvement of the technology behind.The dissertation introduces the process of building the LTE system-level simulationplatform. The first is to understand the process of building the simulation of communicationsystem as a whole; And then build the system level simulation platform by different parts oneby one: Base station side, the user side, the noise model and the business model; Finally,simulation-evaluation indicators is listed, including user access rate, SINR distribution,system capacity, each modulation mode ratio and so on. Building the simulation platformprovides a test platform for the improvement scheme of subsequent, and provides support toverify the final effect.After the analysis of the shortage of traditional scheme, aiming at the defects of the oldscheme, a new scheme is proposed, and the simulation is conducted. Firstly, the interferencecoordination classification are introduced, and the static interference coordination, semi-staticinterference coordination and dynamic interference coordination is introduced in detail. Thenthe traditional interference coordination scheme is simulation-tested. At the same time, weprove that interference coordination scheme has more advantages than common frequencyreuse schemes, and also points out its defects to improvement. Then, this dissertationproposes a new scheme based on the division method of comprehensive considering the SINRand distance. Finally, using the LTE system-level simulation platform to verify theimprovement scheme, and compare it with the traditional SFR scheme and frequency reuse scheme, improving that new scheme improves the system performance. |
