Performance Analysis Of LTE System With Shorter Transmission Time Interval

LTE system is the major milestone in stepping towards 4G evolution. As pre-version of 4G, it has been widely used and has been highly recognized by people. With the rapid development of mobile Internet technology, the Internet data transmission is also growing, and causing more and more mobile Internet traffic types. The current LTE system can not meet such a large throughput and low delay requirements. In order to meet these requirements, wireless communication technology must develop towards the 4.5G (also known as LTE-Advance) system. 4.5G system's main goal is to reduce system transmission delay, and increase system throughput. In order to achieve this goal,we propose short the TTI length to an OFDM symbol, that is, the ultra-short TTI.Compared with the standard TTI, this paper introduces the ultra-short TTI in the LTE system needs to change ultra-short TTI time-frequency resources and ultra-short TTI transmission block. Then, the LTE system with ultra-short TTI and standard TTI is simulated by using the system-level simulation platform.The file transfer (FTP) service is adopted as the data application service of the LTE system in our simulation. Then, we use MATLAB to deal with data prodused by the platform and analyze the performance. Both the advantage and disadvantage produced by LTE system with ultra-short TTI are analyzed.Ultra-short TTI will greatly enhance the LTE system throughput, delay,reliability, resource utilization and other aspects of performance. However,ultra-short TTI also increases the MAC header overhead and bring a tough Qos to User End (UE) in terrible environment.In order to solve the tough Qos problem brought by ultra-short TTI, this paper presents two solutions. One is using 0.5ms length TTI to replace ultra-TTI in LTE system. Another is making a hybrid TTI combining ultra-short TTI and standards apply to LTE systems. Both two solutions can also solve the tough Qos problem brought by ultra-short TTI. However, comparing with LTE performance brought by ultra-short TTI, performance brought by both two solutions is reduced. Finally, through the comparative analysis, the configuration of hybrid TTI LTE system is the best solution to this problem.