In speech recognition, recognition performance is usually affected by the confusing set in the vocabulary. One possible way to improve the discriminability is to decompose speech signal into multifrequency channels with different weights. In this paper, speech signal is decomposed into multiple spatial frequency channels using wavelet transform and filter banks, respectively. Speech signal in e...

From the communication channel and implementation aspects of communications, the transmission environement may be sufficiently degraded, e.g. a multipath fading channel, that acquiring and tracking a coherent demodulation reference signal is practically difficult. Coherent receivers require exact knowledge of the channel phase for optimum performance. Due to the difficult task of estimation cha...

In this research we have investigated the performance of using an adaptive NLMS lter to cancel the impulse noise on powerlines. Using 930 impulses from various sources, which had measured and collected between the live-neutral channel(LN) and neutralearth channel(NE) of the powerline, we have simulated our proposed adaptive algorithm. Di erent cancellation results have obtained via changing the...

Channel overloading, which refers to accommodating a larger number of users on a channel than can be achieved with orthogonal signaling, is currently a very hot topic for future wireless systems. A number of approaches have been described in the literature, and the most efficient of them use several sets of orthogonal signal waveforms. Multiuser interference, which is inherent to channel overlo...

We propose and experimentally demonstrate a wavelength-division multiplexed (WDM) optical stealth transmission system carried by amplified spontaneous emission (ASE) noise. The stealth signal is hidden in both time and frequency domains by using ASE noise as the signal carrier. Each WDM channel uses part of the ASE spectrum, which provides more flexibility to apply stealth transmission in a pub...

© 2010 Chengshi Zhao et al. 11 A novel ultra-wideband (UWB) transceiver structure is presented to be used in wireless body area networks (WBANs). In the proposed structure, a data channel and a control channel are combined into a single transmission signal. In the signal, a modulation method mixing pulse position modulation and pulse amplitude modulation is proposed. A mathematical framework ca...

Scorpion venom is the richest source of peptide toxins with high levels of specific interactions with different ion-channel membrane proteins. The present study involved the amplification and sequencing of a 310-bp cDNA fragment encoding a beta-like neurotoxin active on sodium ion-channel from the venom glands of scorpion Androctonus crassicauda belonging to the Buthidae family using r...

—For a time-hopping (TH) pulse position modulation (PPM) based ultra-wideband (UWB) multiantenna system, we propose four coherent space-time (ST) diversity schemes, corresponding to which the correlation template signals with blind channel estimation are also presented. First of all, the issue of channel identifiability based on first-order statistics is addressed, aspired by the singleantenna...

A narrowband channel model for multipath fading in aeronautical telemetry applications is described. This channel is composed of a line-of-sight signal, a specular reflection whose strength is 20% to 80% that of the line-of-sight signal, and a diffuse multipath component whose power is 10 to 20 dB less than that of the line-of-sight signal. Thus the channel is close to additive white Gaussian n...