SPECTRAL ANALYSIS DEVICE FOR THE OPTIMAL ESTIMATION OF THE AUTOSPECTOR OF A SIGNAL OF THE INTERSPECTOR OF TWO SIGNALS AND ITS APPLICATION TO THE ESTIMATION OF AN INTERSPECTRAL MATRIX

摘要

P The signals from sources 10 are converted to digital form 14 and undergo a Fourier transformation to obtain their frequency transforms. The processing circuit 20 is arranged to calculate the log-periodogram of a signal and the interperiodogram of two signals. Means 24 realize the optimal smoothing of the Log-periodogram or of the interperiodogram by calculation of an optimal weighting window. The estimated autospectrums and interspectrums are obtained after smoothing. By implementing a recursive algorithm comprising estimates of autospectrers and interspectrums, a set of signals can be decorrelated and whitened, leading to the estimation of the interspectral matrix. The invention finds a particular application in the processing of electroencephalographic signals, in particular for brain mapping, the location of sources of brain activity and the search for relationships between them. /P