基于傅里叶系数映射的OFDM系统性能分析

摘要

针对正交频分复用(OFDM)系统存在较高峰均比的问题,通过分析OFDM调制系统与周期信号傅里叶级数展开的关系,提出一种基于傅咀叶系数映射的OFDM技术方案.该方案将待传输的数据调制为周期性信号,取该信号的部分傅里叶系数进行OFDM调制,替代传统的QPSK或MQAM映射方式.仿真结果表明,该技术方案在和QPSK映射相同频带利用率的情况下,其峰均比可下降3 dB,误码率与QPSK映射基本相当.%Orthogonal Frequency Division Multiplexing(OFDM) has high Peak to Average Power Ratio(PAPR) problem.This paper proposes a new OFDM system based on Fourier coefficient mapping through studying the relation between OFDM modulation system and the Fourier series expansion of periodic signals.This method modulates the transmit data into periodic signals and takes part of the Fourier coefficients for OFDM modulation.Simulation results show that the PAPR of this new method can be reduced 3 dB compared with QPSK mapping and the BER performance is almost equal to QPSK mapping under the same bandwidth efficiency.