Study And Design Of Filter For PAPR Reduction Based On FPGA

As the core technique of the fourth generation mobile communication system(4G),Orthogonal Frequency Division Multiplexing(OFDM)is an efficient multi-carrier technique with high transmission rate,robust anti-multipath fading ability,high spectral efficiency,bandwidth scalability and so on.It could meet the high data rate of communication requirements,so it has been widely used.The signal of the OFDM system is the superposition of a series of signals of its sub-channels,and the OFDM signal may have a higher peak to average power ratio(PAPR)if the phases of the multiple signals coincide,which would bring a great negative impact on follow-up processing,such as the higher dynamic range requirement of the digital-to-analog converter and the wider linearity range requirement of the power amplifier in the system.Accordingly,in the actual system,the suppression of the PAPR is an indispensable task,and many experts and scholars are working on more robust PAPR reduction techniques of OFDM.With respect to the problem of high PAPR,we have summarized the recent research and development on PAPR reduction based on the analysis of the theory and key technologies of OFDM technique in this paper,analyzed and compared the performance of various classical PAPR reduction techniques,including the ability to suppress PAPR,the complexity of the system,the data transmission rate and the bit error rate(BER)of the system.Finally,a PAPR reduction scheme for OFDM system which combines the partial transmit sequence(PTS)and the companding transformation is proposed.It takes advantage of the PTS,which does not cause signal distortion with linear transform,and the companding transformation,which is simple and direct.In order to ensure BER and transmission rate in this joint algorithm,simplifying the iterative process of phase rotation factor and reducing the inverse companding coefficient of the receiver had been adopted.We also adopt MATLAB and ISE tools of Xilinx to model and design FPGA implementation of the new algorithm.The simulation results show that the new scheme improves the PAPR performance about 0.5dB and 6dB respectively compared to the PTS and companding transformation with the same parameters,and ensures BER and transmission rate at the same time,which has strong adaptability and practicality.At the end of this thesis,a serious summary about the work is presented,pointing out that the new algorithm has its own technical superiority but still needs further improvement.In the meanwhile,we also provide a clear direction for future research.