Part Of The Transmission Sequence Based Multicarrier System Peak Than Inhibition Technology Research

Multicarrier communication technology, such as orthogonal frequency division multiplexing (OFDM), owning to its high bandwidth efficiency, resistance to narrowband interference and frequency-selective fading, has been selected as the major candidate technique for the future wireless communication systems. However, high peak-to-average power ratio (PAPR) is one of the biggest shortcomings in OFDM system. In this case, when OFDM signals which have high peak values traverse high power amplifier (HPA), which may cause non-linear distortions, and therefore degrade the performance seriously. According to the problems above, this dissertation focuses on the distortionless PAPR reduction proposal about partial transmit sequence (PTS) in multicarrier communication systems.The first chapter of this thesis introduces the multicarrier communication technology and multiple access techniques, points out its high PAPR problem, analyzes current popular PAPR reduction schemes, and summarizes the research topics in this thesis.In the second chapter, introduces the OFDM, Single Carrier Frequency Domain Multiple Access (SC-FDMA) and long term evolution advanced (LTE-A) uplink system, clarifies the measure mechanism of PAPR and analyzes the PAPR features of OFDM and SC-FDMA signals, introduces the principal of PTS, which serves as the theoretical base of the following chapters.Chapter3studies PAPR reduction techniques of OFDM system based on the modified PTS algorithm. To deal with the problem of high computational complexity in PTS scheme, proposes a modified PTS algorithm based on phase factor sorting with threshold by analyzing the correlation of the candidate signals, which can narrow down the searching for candidate signals.Chapter4is to deal with the drawback of PTS with transmission of extra side information. To solve this problem, blind PTS schemes both in frequency-domain recovering and time-domain recovering are proposed for the block-type pilot OFDM systems. Chapter5proposes three PTS schemes applied in uplink transmission, and compares their performance. Analysis of simulation results shows that time-domain PTS providing the best PAPR reduction performance. In addition, this chapter also discusses the PAPR/CM reduction proposals in LTE-A, proposes a reference signal (RS) design method according to PAPR/CM. Since RS in uplink is block-type located, simulation results demonstrate the blind PTS in OFDM system also can apply in LTE uplink.In the last chapter of this dissertation, summarizes whole article and points out the further research directions in PAPR reduction in multicarrier communication system.