If the DFT (Discrete Fourier Transform) is used to convert sample data in the time domain, and transform it into the frequency domain, then it seems reasonable to surmise that if you perform the inverse transform on the frequency domain data you will be able to recover the original time domain data.Hello Papabravo,I know that FFT converts continues data into descrete frequency domain.but i cant see hoe it could be used for demodulation.
Exactly.If the DFT (Discrete Fourier Transform) is used to convert sample data in the time domain, and transform it into the frequency domain, then it seems reasonable to surmise that if you perform the inverse transform on the frequency domain data you will be able to recover the original time domain data.
A. Discrete Fourier Transform
Throughout the development of OFDM technology, there have been a number of remarkable contributions. The first milestone came about in 1971 when Weinstein and Ebert [10] used a discrete Fourier transform (DFT) to perform baseband modulation and demodulation in the receiver. It should be noted that in 1970, the application of the DFT to an FDM system was first proposed by Darlington [11]. This renovation of the original analog multicarrier system to a digitally implemented OFDM eliminates banks of subcarrier oscillators and coherent demodulators and thus reduces the implementation complexity. This evolution makes the modern low-cost OFDM systems plausible today.