The convex geometry of subchannel attenuation coefficients in linearly precoded OFDM systems

Authors:
J. H. Manton
Affiliations:
ARC Special Res. Centre for Ultra-Broadband Inf. Networks, Univ. of Melbourne, Vic.
Venue:
IEEE Transactions on Information Theory
Year:
2006

Citing 0
Cited 2

Modulated Coded OFDM Systems with Special Precoder

Wireless Personal Communications: An International Journal
A novel Haar wavelet-based vector BPSK–OFDM robust to channel spectral nulls and with reduced cyclic prefix length and PAPR

International Journal of Communication Systems

Quantified Score

Hi-index	754.84

Visualization

Abstract

Channels with spectral nulls are sometimes dubbed bad channels because they can cause poor performance in communication systems. This article investigates the validity of this intuition by studying the geometry of an orthogonal frequency-division multiplex (OFDM) system. It is shown that the subchannel attenuation coefficients form a natural coordinate system for describing finite-impulse response (FIR) channels in an OFDM framework. It is also shown that channels with spectral nulls are geometrically significant; they form the faces of the convex set of all subchannel attenuation coefficients. This novel perspective makes it immediately clear why the worst performance of a linearly precoded OFDM system is achieved over a channel having the greatest number of spectral nulls. The practical implications of these results are discussed