In this paper, the performance of various Pulse Position Modulation (PPM) schemes has been analysed for PIN and APD receivers in the presence of atmospheric turbulence. It is observed that the performance of the APD receiver is always better than that of the PIN receiver as expected. Among the various modulation schemes, the performance of Differential Amplitude PPM (DAPPM) scheme with more num...

This paper presents a method for segregating and recognizing concurrent vowels based on the amplitude modulation spectrum. Vowel segregation is accomplished by F0guided grouping of harmonic components encoded in the amplitude modulation spectrum while vowel recognition is achieved by classifying the segregated vowel spectrum. Main features of the method are (1) the reassigned technique is emplo...

Spot size reduction is demonstrated by printing focused spots from amplitude-modulated radially polarized light at the wavelength λ = 405 nm on a photoresist. Amplitude modulation is realized by ring illumination and by application of an optimized amplitude distribution function. Amplitude modulation is implemented via spatial light modulator, which is followed by a specially designed radial wi...

The behavior of the structure amplitude is analyzed in terms of the harmonics of a modulation function for the case of one-dimensional longitudinal displacive modulation. This modulation function is given by a finite series of N sine functions. It turns out that: (1) for the large values of the amplitudes of the modulation function the structure amplitude tends to zero for the arbitrary values ...

Abstract—Sub-Nyquist sampling jamming method (SNSJ) is a well known deception jamming method for inverse synthetic aperture radar (ISAR). However, the anti-decoy of the SNSJ method performs easier since the amplitude of the false-target images are weaker than the real-target image; the false-target images always lag behind the real-target image, and all targets are located in the same cross-ran...

We report on a terahertz spectrometer for high-resolution molecular spectroscopy based on a quantum-cascade laser. High-frequency modulation (up to 50 MHz) of the laser driving current produces a simultaneous modulation of the frequency and amplitude of the laser output. The modulation generates sidebands, which are symmetrically positioned with respect to the laser carrier frequency. The molec...

This paper presents an alternative method for determining exact expressions for the bit error probability (BEP) of modulation schemes subject to Nakagami-m fading. In this method, the Nakagami-m fading channel is seen as an additive noise channel whose noise is modeled as the ratio between Gaussian and Nakagami-m random variables. The method consists of using the cumulative density function of ...

A listening test has been performed to investigate the relationship between human annoyance and the amplitude modulation of wind turbine noise. To obtain sound samples for the listening test, sound from a 1.5 MW wind turbine in Korea was recorded. The strength of the amplitude modulation of the sound samples was defined in terms of the modulation depth spectrum, which was approximated by assumi...

Studies on sine-wave speech (SWS) perception suggest that formants contain sufficient information for sentence intelligibility. This study further investigated the effects of amplitude modulation, number of sine-waves, and vowel resonance in SWS recognition. Results showed that Mandarin sentences synthesized using frequency trajectories of the first two formants were highly intelligible with ad...

We investigate the possibility of using a real-axis spatial light modulator (SLM) to realize complexamplitude modulation with full coverage over the unit circle. The real-axis SLM produces a pixelated bipolar-amplitude wavefront. Each pixel is basically a spatial pulse width with the signal information being carried by the pulse’s amplitude. Data streams generated in this manner have real and i...