Title :
Noise analysis of DMT
Author_Institution :
Telecommun. Res. Center Vienna, Austria
Abstract :
We consider discrete multitone (DMT, baseband OFDM) modulation and perform a detailed noise analysis which takes into account dependencies and power differences of the real and imaginary parts after the complex valued discrete Fourier transform (DFT). We show that for colored noise, rotated rectangular symbol constellations are more appropriate than the common (quadratic) QAM symbol constellations with respect to capacity and symbol error probability, and we derive formulas for the rotation angles and constellation sizes/densities.
Keywords :
OFDM modulation; covariance matrices; discrete Fourier transforms; error statistics; quadrature amplitude modulation; random noise; DFT; DMT modulation; QAM symbol constellations; baseband OFDM modulation; capacity; colored noise; constellation densities; constellation sizes; discrete Fourier transform; discrete multitone modulation; noise analysis; pseudo-covariance matrix; rotated rectangular symbol constellations; rotation angles; symbol error probability; Baseband; Colored noise; Covariance matrix; Discrete Fourier transforms; Equalizers; Image analysis; OFDM modulation; Performance analysis; Random processes; Symmetric matrices;
Conference_Titel :
Global Telecommunications Conference, 2003. GLOBECOM '03. IEEE
Print_ISBN :
0-7803-7974-8
DOI :
10.1109/GLOCOM.2003.1258613
