Research On Reducing PAPR Of TDD LTE System

With the communication system is toward to broadband, integrated, mobile technology, personal and intelligent, It is necessary to find a mobile communication system which have higher transportation speed. LTE communication system came out at this time, LTE project are mobile communications and broadband wireless access technologies and effective integration. OFDM and MIMO is the key technology of LTE. Especially the OFDM modulation technique provides a higher frequency of utilization. However OFDM modulation because its subcarriers superimposed in the time domain, its signal have a problem of too large of PAPR (Peak to Average Power Ratio, PAPR). The problem resulting in lower power amplifier efficiency, so that easily lead to distortion of the signal distortion, thus reducing the overall system performance.This paper research on how to reduce PAPR of TDD LTE system. First of all, introduce the key technology of TDD LTE system. Following introduce the basic model of OFDM signals and the reason why the OFDM signal have the too PAPR. There always have three methods to reduce PAPR, Limiter type, probability type and Coding type. In this paper we simulate probability type use MATLAB, such as SLM, PTS. The paper focus on the way of tone reservation which include by probability type. Simulation of Space search algorithm and Gradient algorithm of TR algorithm and also be certified that the algorithm is non loss for OFDM signals . At last, reduction of PAPR on IF is induced. Design and simulate the method of noise shaping on IF to reduce PAPR. Thus avoid the problem of regeneration of peak value. This provided a vivid ideal to realize the algorithm of decreasing of PAPR.