Title :
Asymmetric OFDM Systems Based on Layered FFT Structure
Author :
Zhang Jian ; Jayalath, A.D.S. ; Ying Chen
Author_Institution :
Nat. ICT Australia, Canberra
Abstract :
In this letter, we first extend the convolution theory of discrete Fourier transform (DFT) and introduce a structure of layered fast Fourier transform (FFT). Based on this framework, we propose novel asymmetric orthogonal frequency-division multiplexing (OFDM) systems that bridge general OFDM and single carrier systems. Adaptive to the capability of the transceiver, asymmetric OFDM systems provide significant flexibility in system design and operation. We show how effects of noise enhancement and frequency diversity counteract each other in asymmetric OFDM systems. Performance comparison with general OFDM and single carrier systems is also given.
Keywords :
OFDM modulation; convolution; discrete Fourier transforms; diversity reception; transceivers; asymmetric OFDM system; convolution theory; discrete Fourier transform; fast Fourier transform; frequency diversity; layered FFT structure; noise enhancement; orthogonal frequency-division multiplexing; single carrier system; transceiver; Australia; Bridges; Convolution; Discrete Fourier transforms; Fast Fourier transforms; Frequency division multiplexing; OFDM; Peak to average power ratio; Signal processing algorithms; Transceivers; Fast Fourier transform (FFT); frequency diversity; orthogonal frequency-division multiplexing (OFDM); peak-to- average power ratio (PAPR);
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2007.903230
