Today, a variety of technical devices deploy spoken language processing technology. In many practical use cases, not only stationary ambient noises but non-stationary interferences, such as wind noise, degrade their performance. If only one microphone is available, regular noise reduction schemes are capable of suppressing stationary interferences. Wind noises, however, are highly non-stationar...

Varying speed machinery condition detection and fault diagnosis are more difficult due to non-stationary machine dynamics and vibration. Therefore, most conventional signal processing methods based on time invariant carried out in constant time interval are frequently unable to provide meaningful results. This paper deals with the detection of bearing faults in gearbox under non-stationary run-...

It is very common to consider voiced speech as a periodic or quasi-periodic signal. Therefore, harmonic models are usually proposed for the modeling of this kind of speech. This paper focuses on the harmonic analysis of speech. Three models are presented and compared. The rst model is the simplest among the three models supposing that the speech signal is a stationary signal. The second model d...

The vibration signal carries the signature of the fault in most rotating equipments, and early fault detection of a fault is possible by analyzing the signal using different signal processing techniques. In this paper we consider gearboxes as a typical representation of a rotating or cyclo-stationary process. Faults in gearboxes leave their signature on the vibration signal with an increased pr...

One of the most difficult classes of signal detection problems is detecting a non-stationary signal in a non-stationary environment with unknown statistics. One of the most interesting approaches considers the use of a neural network to compute the likelihood ratio of the received signal, by training it on different realizations of the received signal. The signal detection problem is then trans...

The multi-scale Hermitian wavelet order envelope spectrum based bearing fault detection and diagnosis method under run-up condition is presented in this paper. This new approach based on the fusion of the computed order tracking, Hermitian wavelet transform and envelope spectrum is used for detection defects in roller element bearings. Firstly, Non-stationary vibration signal under run-up condi...

In this paper, the characteristics of received Global Navigation Satellite System (GNSS) signal amplitudes are analyzed under different scenarios including urban, semi-urban, foliage and indoor environments. Stationary, cyclostationary and nonstationary analyses are used to characterize the variations of the received signal amplitude under the aforementioned scenarios and various propagation mo...

Adaptive Array, with spatial processing, used in CDMA multiuser communications can enhance range, reliability and capacity. Moreover, the adaptive beamforming technologies can remove unwanted noise and interference from the received signal. In this paper, we propose four adaptive antenna receiver structures for DS/CDMA multiuser environment with multipath fading channels. LMS and RLS algorithms...

Time-varying short-term spectral estimates have been successfully applied in many classification tasks. However, they are still insufficient for many non-stationary signals where time-varying information is useful. In this paper, we propose to improve the deficiencies of current short-term feature analysis by adding information to describe the time-varying behavior of the signals. Our proposed ...