Investigating of The Reducing Techniques for The Peak to Average Power Ratio(PAPR) in OFDM Systems

摘要

High Peak to Average Power Ratio (PAPR) for OFDM system is still a demanding area and difficult issue. The radio transmitter stations for covering and getting enough transmit power in their desired area have to use High Power Amplifier (HPA). On the other hand, in order the HPA have the most output power efficiency must be designed to work close to the saturation region therefore due to the high PAPR of input signals a factor which is called memory-less nonlinear distortion will be come into the communication channels. We know the OFDM receiver's efficiency is sensitive to the HPA. If the high power amplifier doesn't work in linear region it can cause the out-of-band power to be kept under the specified limits. This condition can cause inefficient amplification and expensive transmitters, thus it is necessary to investigate PAPR reduction techniques for OFDM system. By now, for reducing PAPR in OFDM systems, numerous techniques have been recommended. In this paper the performance and the efficiency of a number of them will be discussed and evaluated and then we proposed our suggested method for a conventional OFDM system.