Interferer Rejection Improved by Noise in Ultra-Wideband Telecommunications

Abstract

Ultra-wideband technology uses baseband transmission of low-power ultra-short information-bearing impulses, and represents a promising approach for very-high speed wireless communications with multiple access, as well as for low-rate high-accuracy positioning systems. The first demonstrations of the huge potential of ultra-wideband were based on hypotheses of perfect power control and multiuser interferences modeled as white Gaussian noise. Here, by explicitly modeling the interference with an external impulse signal, we demonstrate the possibility of improving the rejection of the interferer thanks to a constructive action of the noise. This is interpreted as a novel instance of the phenomenon of stochastic resonance or improvement by noise in signal processing.

Tuning the Noise in Magnetic Resonance Imaging to Maximize Nonlinear Information Transmission

“…4 operate when, in absence of noise, the level of the pixels related to both object and background are located bellow the fixed threshold θ of the quantizer in Eq. (9). In such a configuration, the threshold θ is too large, ill-positioned, to perform a good binary classification of the pixels in the noisy modulus image M N (u 1 , u 2 ) and our analysis demonstrate that an increase of the level of the noise by tuning the receiver bandwidth of the MRI apparatus can benefit to the transmission of the information carried by the output image Y (u 1 , u 2 ).…”

“…Stochastic resonance, since its introduction [6] in the domain of nonlinear physics, has gradually emerged as a general paradigm of noise-assisted information processing, reported to operate in many different areas such as electronic circuits, lasers, neurons, nanodevices or chemical reactions [5,7]. Stochastic resonance has mainly been reported with mono-dimensional signals for various digital processes (including for instance quantization [8] detection [9] or estimation [10]) and its application to images is more recent [11][12][13][14][15][16][17]. Also, stochastic resonance has essentially been explored with additive signal-noise coupling [7], and less frequently with multiplicative signal-noise coupling [14,[18][19][20].…”