The behavior of the classic algorithm for blind source separation (BSS) is detailed for a fixed step size. To improve the algorithm in speed and exactness, essential in tracking a time-varying mixing environment, a variable step size must be employed. The ideal step size should decrease or increase as the overall system error decreases or increases. It is shown analytically that the coefficient...

The non-destructive evaluation of the rail is crucial to provide a high safety level in railway transportation. To detect and classify on line rail surface defects (splitted rail, shelling ...), a specific double-coils double-frequencies eddy current sensor is used, which gives 8 real differential signals. Blind Source Separation (BSS) is applied to dissociate the different classes of defects o...

Blind Source Separation (BSS) is often carried out under the assumption that sources are statistically mutually independent, at least in the sense of cumulants of given order. However, this assumption is not mandatory, and can be replaced by some assumption on the source distribution, even if all sources are identically distributed. Contrast functions are optimization criteria that satisfy some...

Audio source separation is a useful preprocessing step for remixing or transcription of music. It can be shown, that the separation quality increases, if the separation algorithm gets additional side information, e.g. the score of the current mixture [5]. In many cases the score of a musical piece is not available and has to be extracted by a professional musician or an automatic music transcri...

This paper addresses the problem of blind source separation (BSS). To recover original signals, from linear instantaneous mixtures, we propose a new contrast function based on the use of a double referenced system. Our approach assumes statistical independence sources. The reference vectors will be incrusted in the cumulant to evaluate the independence. The estimation of the separating matrix w...

The blind source separation problem (BSS) consists in extracting uncorrelated sources from an observed linear mixture. The rationale behind BSS is to reconstruct correctly the waveform of the signals allowing arbitrariness of their sign, order and energy. Known closed-from solutions succeed by relying on specific assumptions about the source distributional form. For more complex signal, such as...

Signal processing in the CDMA downlink is a challenging task since the codes of the disturbing users are unknown. Blind source separation methods could be used for this task, but they fail when the fading process is Gaussian, which is often the case in CDMA. In this paper, we try to solve the problem by using semi-blind approach: only the code alphabet is assumed to be known, i.e. s k 2 f?1; 1g...

Blind Source Separation (BSS) is a prominent problem in signal processing. In the past few decades, it was applied to many fields, in which separation of compound signals, simultaneously observed by different sensors, is of interest. The problem can be considered as built-up of three physical elements: sources (also called transmitters), sensors (also called receivers) and communication channel...

We discuss overcomplete blind source separation (BSS), that is separation with more sources than sensors. Finding the mixing matrix solves the linear quadratic BSS problem; in overcomplete BSS however, it is then still not clear and not even unique how to get the sources from the mixtures and the mixing matrix. We therefore follow Bofill and Zibulevsky in [5] and many others and take a two-step...