Research On The Method Of TD-LTE Interference Investigation

Before the formal construction of TD-LTE(Time Division-Long Term Evolution) network, according to a large number of research results coming from a domestic telecom operator's large-scale test network in some cities, the current situation of wireless communication network frequency assignment show that frequency bands allocated for TD-LTE may face extremely complex and various interference in China. If these interference problems cannot be effectively solved, the progress of construction and the quality of TD-LTE network operation will be severely affected. TD-LTE interference assessment, investigation, evasion and settlement are so complicated that require higher professional knowledge. A deep understanding of the wireless network technology characteristics, and a full understanding of the equipment performance from communications industry mainstream manufacturers and construction of telecom operators are needed. Based on the actual work experience of frontline staff from telecom operators, this article investigates and demonstrates the TD-LTE interference investigation methods, aiming at making TD-LTE interference investigation work more efficient and reasonable and carrying out elimination external interference of the LTE planning bands more timely and effectively, to ensure that the LTE sites built as they are planned are no longer LTE network optimization problems and black holes.This paper mainly includes the following three parts:Firstly, the process and methods of the interference are summarized, the types of TD-LTE system interference are analyzed and summarized. The range of cause and effect for inter-system interference of TD-LTE system are proposed.Secondly, we propose a new way to investigate the TD-LTE interference investigation by combining “rapid screening of the entire network interference” with “accurately locating the single site interference”. We've deeply studied the concept, feasibility, process and details of those three kinds of TD-LTE interference troubleshooting methods: "TD- LTE road frequency scanning", "the full spectrum frequency sweep using TD-SCDMA(Time Division-Synchronous Code Division Multiple Access) ISCP(Interference Signal Code Power)" and "interference investigation by manual work on station". Among them, the last method involves the most knowledge related to interference screening and it is most widely used by frontline technicians. The article analyzes emphatically on requirements for related instruments and meters, preparing work and investigation methods. Interference source investigation and locating methods are analyzed and studied in detail. Several kinds of usual TD-LTE interference provention and resolving solutions are also illustrated and enumerated in the article as improvement and supplement to interference checking methods, in order to put the interference investigation work into practice.Finally, the TD-LTE interference investigation methods are validated by using some work examples. Feasibility and practicability of these methods are verified by analyzing the data of a city's interference investigation work, meanwhile, the limitations of these methods and the impact of the operators network are analyzed, to ensure that these methods of interference investigation can be applied to the work practice.Using the scientific and effective interference investigation methods and measures to reasonably avoid and eliminate intersymbol interference which possibly exist in the system before the network construction of TD-LTE, relieving the operator of the burden of network construction and optimization of work, these two are exactly the important function and practical meaning of the study of the TD-LTE interference investigation.