This lecture first introduces the standard representation of complex baseband signal of digital modulated signal and its power spectral density (PSD). Then it shows how the PSD of bandpass signals can always be obtained by its complex baseband envolope. Finally, two important modulation schemes OFDM and PSK are introduced and the spectral characteristics of these two modulated signals are discu...

To reveal the acoustic characteristics associated with hypernasality and to ascertain their correlation to the severity of hypernasality, 30 speech samples produced by 15 maxillectomy patients were acoustically analysed with and without an obturator prosthesis in place. The isolated, sustained Japanese vowel /i/ was used as the stimulus for acoustic measurement and perceptual judgment to evalua...

At present, active search for possible chaos applications goes. However to apply dynamical chaos, it is necessary to have signal sources generating chaotic signals. As is known, chaotic oscillators play the role of the sources. Now, there is a large variety of chaotic oscillators which differ from each other by both the structure and elements, and which have various characteristics. On the othe...

an ideal fusion method preserves the spectral information in fused image without spatial distortion. the pca is believed to be a well-known pan-sharpening approach and being widely used for its efficiency and high spatial resolution. however, it can distort the spectral characteristics of multispectral images. the current paper tries to present a new fusion method based on the same concept. in ...

The great increase of the number of users requires efficient management of the spectrum. In hierarchical cellular systems based on CDMA, FBRA algorithm is proposed to allocate frequency spectrum more efficiently. This algorithm lends frequency spectrum of macrocell to microcells when mass hot spot occurred. We analyze the interference to signal ratio and reverse link capacity in case of using t...

soil surfaces in arid and semi-arid lands often lack photoautotrophic life but are covered by communities of soil surface covering organisms able to tolerate dehydration, and thus adapted to aridity. one important objective of multi-spectral remote sensing instruments is the detection of the optical characteristics of the earth’s surface using high spectral resolution bands. in this study aster...

satellite imagery was used as a rapid and spatially explicit method to delineate crop residue cover and to estimate the use and intensity of conservation tillage. the potential of multispectral high-spatial resolution of worldview-2 local data was evaluated using 11 satellite spectral indices and linear spectral unmixing analysis (lsua). experimental plots were examined; residue cover was measu...