Research On Reducing The Peak-to-Average Power Ratio In Multi-Carrier Systems

Multi-carrier modulation system (MCM) has received significant attention in various applications, not only for its robustness against the multi-path interference, but also for its high bandwidth efficiency. Orthogonal frequency division multiplexing (OFDM) is a special multi-carrier modulation. Although OFDM has many advantages, it has a problem which is high peak-to-average power ratio (PAPR). It is a serious defect, which results in these serious problems such as nonlinear distortion and increases bit error rate of receiver, next-channel interference. According the problems mentioned above, the dissertation focuses on reducing the PAPR algorithms designed for multi-carrier modulation system.Firstly, the dissertation introduces the basic principle of multi-carrier systems, including the system model, system component and advantages or disadvantages. It also gives detailed introduction of the conventional PAPR reduction methods. Secondly, the dissertation presents two kinds of novel PAPR reduction methods: one is adaptive compression and expansion arithmetic based on distortion technology, the other is the dummy sub-carrier insertion based on distortionless technology. All these methods can reduce the PAPR effectively and be used for different kinds of modulation or different number of carriers. Thirdly, the dissertation works up the multi-cartier jamming technology and proposes a novel peak value reduction by using compensation signal. Finally, the relative research and simulation about the whole paper is summarized, meanwhile, the further practical research is expected.