Research On Peak To Average Power Suppressing Technology Of LTE-OFDM System

Currently the mobile communications has entered the4G fields that LTEstandard fields. For traditional communication field, The proposing of LTEbrings great breakthrough in data transfer rate, System Capacity, Anti-jammingcapability and Spectrum utilization. OFDM (Orthogonal Frequency DivisionMultiplexing) technology is the main core of LTE standard, it has the advantagesof high spectrum efficiency, strong ability to resist frequency selective fading,and so on, But due to its subcarrier independent modulation mechanism in a row,there is the problem of PAPR (Peak to Average Power Ratio) on the high side, itwill affect the battery life of the hand-held terminal and the costing of Poweramplifier, limits the range of application of OFDM technology.So, this article is in the context of LTE. Briefly introduces the schemeselection process of LTE standard solutions, and analyzed the the coretechnology OFDM from several aspects. To the peak to average power ratio(PAPR) problem which the system exists, this article from the mathematicaldefinition, the statistical characteristics and measurements of PAPR conducted adetailed analysis. And summarizes the relevant parameters which affect the PAPR,Find out the conclusion that the traditional method because of its force limitercutting principle, existting high-band radiation, large BER problem.The signal with a high PAPR values through the power amplifier of OFDMwill generatting the nonlinear distortion, So this paper estimating the nonlinearchannel of OFDM system, analysising the effects of high PAPR signal caused bythe system, and simulation analysis Traditional high PAPR suppression systemand limiting method, the traditional method with high-band radiation and higherror rate shortcomings because of its force limiter cutting principle. The traditional method can not achieve the requirements that limitingeffective of system PAPR without affecting the bit error rate. So this articlefocuses on the class of probability PTS suppression algorithms, studied andoptimized to improve. Respectively, from the grouping perspective of algorithmsand removing side information to improve the performance of optimizationalgorithms, proposing m-sequence packets optimization methods and PICimproved algorithm. Analyzing and comparing with PTS traditional algorithmoptimization and improved algorithm. Proposed optimization algorithm based onm-sequence packet mode, and removing the side information reducing thenumber of IFFT operations to improve the PIC algorithm, comparing andanalyzing optimization and improved algorithm with traditional PTS algorithm.Respectively, from the theoretical expression systems, data analysising,simulation and contrasting, illustrates the improved algorithm under conditionsof sub-carriers of smaller has closing BER performance to the traditional PTSalgorithm, and computational complexity improved significantly to traditionalalgorithm, the PAPR suppressing performance can also be achieved satisfactoryresults.