Research On Inter-Cell Interference Coordination In TD-LTE System

On December4,2013, the Ministry of Industry and Information Technology officially announced that "the fourth-generation digital cellular mobile communication services (TD-LTE) business license" was issued to China Mobile, China Unicom and China Telecom, commonly known as4G license. TD-LTE officially entered the commercial application in China. How to guarantee the users QoS cost-effectively is the focus in TD-LTE research.In the LTE system, the inner cell subcarriers are orthogonal to each sectors, intra-cell interference is small enough to be negligible. But in the cell edge sector, OFDM signal with the process delay and multipath effects will lead to inter-cell interference, so the inter-cell interference is the main sources of interference in LTE system. This paper focus on how to reduce inter-cell interference by algorithm, guaranteed users QoS in multi-cell communication system.This paper studies the TD-LTE system protocol specification, key techniques and principles, to complete the work as following points:1. Researched the basic Inter-cell interference coordination scheme: Reuse1, FFR and SFR, summarized their performance.2. Set up TD-LTE communication downlink model by Matlab simulator, introduced the transmitter, channel, the receiver functions.3. Set up7cells model, through theoretical research, calculate the number of major/minor subcarriers (Nimajor, Niminor), minimum data rate constraints formula and their respective transmit powers in cell i.4. Introduced the Adaptive Soft Frequency Reuse algorithm based on iterative algorithm. Found out the optimal single-cell’s major/minor subcarriers numbers and their respective transmit powers (N1major, N1minor, P1major,P1minor), through exhaustive method and diminishing method, then execute this method in multi-cells until we find out the appropriate resource allocation combination which meets the multi-cell rates requirement.