Performance Study On LTE System Operating On Different Spectrums

As one of the basic power to accelerate society development,communication has been the necessary part of human civilization.Among the wireless family,mobile communication is the most popular technology which is widely used by individual customers.With the LTE's massive deployment,the mobile communication has entered the 4-th Generation era.Recent years,as the dramatic growth of mobile users,the requirement for the performance of mobile communication system is enhanced.Although the performance of LTE has increased a lot by comparing with former communication systems,it cannot deal with the rapid growth need.Based on this,how to enhance the capacity of mobile communication system is one of the main tasks for wireless communication.This paper focuses on how to improve performance of system by looking for more workable spectrums and increasing the spectrum utilization efficiency.The paper firstly introduces the study background,the related achievements have made in domestic and foreign areas and the relevant technologies,including LTE knowledge and system level simulation.Then the rest of the paper can be divided into two parts,LTE operating on unlicensed bands and FDD flexible duplex for the conventional LTE system.With the idea of finding more useful bands to enhance the upper bound of system capacity,this paper studies the LTE-U,including its coexistence with other wireless system and the cooperation mechanism with the original LTE system.The paper also proposes a resource allocation optimization algorithm based on utility function which can achieve both system efficiency and fairness.Then,the system level simulation illustrates the utility-based resource allocation scheme has positive effect for improving system performance.In the field of enhancing the present LTE system's spectrum utilization efficiency,this paper focuses on flexible duplex for FDD system.In this part,the potential scenario for FDD flexible duplex is studied,and project exploits DLPC and CCIM to mitigate the interference problem.Then,a proportion based algorithm for dynamically re-assigning resource is proposed.And the system level simulation results show that the FDD flexible duplex is useful for enhancing the system capacity.In summary,according to these two aspects studies,this paper achieves positive results on both LTE-U and FDD flexible duplex,which means by exploiting these scheme,LTE operating on both unlicensed bands and original bands can obtain system performance enhancement.