Deutsche Thomson-brandt Gmbh

Claus Muschallik

Veit Armbruster

In an OFDM system, the so-called self-noise component, which represents that noise component of the respective carrier which is caused by the carrier itself and is mapped onto itself, can be estimated and corrected by shifting all the carriers back in the receiver by multiplication by a factor which is determined by averaging. The so-called external-noise component, which is caused by adjacent carrier interference from the so-called leakage effect of the Fast Fourier transform (FFT,) used in the receiver for demodulation cannot be corrected using this method. In addition to the demodulation FFT, a further FFT (FFT,) is used in the receiver to estimate the self-noise component (&psgr;,). The estimated self-noise component is used to reproduce the orthogonality between the carriers by correction before the demodulation FFT, to thereby prevent crosstalk. The additional FFT (FFT,) may have a shorter length than the demodulation FFT (FFT,), so that the additional complexity is negligible.

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München, Germany

Claus Muschallik