The Research On Peak-to-average Power Ratio Reduction Of OFDM Signals In PLC

Power Line Communication Technique(PLC) attracts more and more extensive attention because of predominance in broadband internet access. Because the power line communication channel has the characteristics of high noise interference, Frequency selective fading and multi-path propagation, so its communication performance is greatly reduced. However, The Orthogonal Frequency Division Multiplexing (OFDM) technique provides an effective resolution to high rate PLC, because it has so many merits, such as high capability to resist noise and multi-path effect,more bandwidth efficiency, simple configuration, low cost, etc.OFDM as a modulation technique has some problems, such as synchronization, Peak-to-Average Ratio (PAPR), and coding and modulation and so on. Being applied in the PLC system, OFDM has a larger problem of PAPR. The large PAPR will reduce the communication performance of the PLC system. How to reduction high PAPR is key point of the paper research.In this paper, the PLC is introduced firstly, and then the characteristics of the power line communication channel are studied. Based on the analyses of channel characteristics, this paper gives PLC channel model. Secondly, OFDM system and problem of PAPR is introduced. Then mainly discusses several methods to reduce the PAPR of OFDM. Finally, this paper is focus on the partial transmit sequences (PTS) algorithm, which belongs to the probability technic. Two new algorithm are presented to reduce PAPR of the OFDM system, and result of simulation show that two new algorithm not only Can reduce the PAPR of the OFDM system,but also can large scale reduce the complexity of computation.