多载波中的实数FFT及其离散Hartley变换实现

Real-valued FFT in MCM and its realization based on discrete Hartley transform

在OFDM/DMT多载波调制中,FFT[1]为实数FFT(Real-Valued FFT),输入全部为实数,变换后的输出为偶函数即具有一定的共轭特性。相应地,IFFT为实数FFT的逆过程。实数FFT的实现与复数FFT具有很大的不同,文中提出了一种基于离散Hartley变换的实现方法,运算过程全部为实数过程,与复数FFT相比,所需的乘法、加法运算以及RAM的开销均大幅度降低。

In multi - cartier modulation of OFDM/DMT, the Fourier transform is real - valued FFT, and the IFFT is the inverse transform of real - valued FFT. The realization of Real - valued FFT is much different from the Complex - valued FIT. In this paper, a discrete Hartley transform - based FFT/IFFT method is discussed. The arithmetic operations are all real- valued, and comparing with the complex-valued FFT, the requirements of RAM, multiplier and adder are highly reduced.