In multicarrier systems, the transmitted timedomain signal exhibits large amplitude peaks. This peak-toaverage power ratio (PAPR) problem complicates the practical use of multicarrier systems: the amplifier used to transmit the signal saturates because of the large peaks and causes non-linear distortion. As this non-linear distortion frustrates severely the detection of the multicarrier signal,...

A R TI C LE Abstract A comprehensive overview is presented about optical fiber-based tunable photonic delay lines, which have been steadily developed over the last decade for the realization of all-optically controlled timing functions. The most widely used techniques, such as those based on slow & fast light and wavelength conversion associated to dispersion, are described and their physical l...

The nonlinearity inherent in the Traveling Wave Tube (TWT) amplifier distorts amplified signals and results in reduced efficiency and bandwidth, limiting its use in communication and electronic countermeasure applications. Signal predistortion is an effective technique for suppressing nonlinear distortion in TWTs that provides high suppression and requires simple circuits for implementation. Wh...

Feed-Forward (FF-) and Feed-Back (FB-) structures have been proposed for Blind Source Separation (BSS). The FF-BSS systems have some degrees of freedom in the solution space, and signal distortion is likely to occur in convolutive mixtures. On the other hand, the FBBSS structure does not cause signal distortion. However, it requires a condition on the propagation delays in the mixing process. I...

The special generator of testing signal was designed for the frequency of 441.171 kHz. The generator consists of the special crystal oscillator and a high power amplifier. The frequency stability of the generator is in order of 10/day, the output power 1W, the value of SINAD is close to 120 dB and the total harmonic distortion under 170 dB by using of linear narrow-band filter.

Many centers are now using high-density microelectrodes during traditional intracranial electroencephalography (iEEG) both for research and clinical purposes. These microelectrodes are FDA-approved and integrate into clinical EEG acquisition systems. However, the electrical characteristics of these electrodes are poorly described and clinical systems were not designed to use them; thus, it is p...

We consider the problem of embedding one signal (e.g., a digital watermark), within another “host” signal to form a third, “composite” signal. The embedding is designed to achieve efficient tradeoffs among the three conflicting goals of maximizing information-embedding rate, minimizing distortion between the host signal and composite signal, and maximizing the robustness of the embedding. We in...

Acoustic ultrasonic measurements are widespread and commonly use transducers exhibiting resonant behaviour due to the piezoelectric nature of their active elements, being designed to give maximum sensitivity in the bandwidth of interest. We present a characterisation of such transducers that provides both magnitude and phase information describing the way in which the receiver responds to a sur...