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The aim of this paper is to investigate the effect of impulsive noise on the performance of the turbo TCM coded OFDM system. We construct a punctured parity-concatenated trellis code which functions as a turbo TCM code but with much lower complexity and explore their application in OFDM systems using 64QAM constellation to offer higher spectral efficiency. The conventional iterative bit MAP decoding...
In this paper, we propose a distributed video coding (DVC) paradigm based on lattice vector quantization in wavelet domain. In this framework, we use a fine and a coarse lattice vector quantizer to wavelet coefficients and the difference of two lattice quantizers is coded by turbo encoder. At decoder, side information is gradually updated by motion-compensated refinement. The refinement is built on...
From recent research works, it has been found that the nano ZnO rods have good field emission performance. This paper compares the emission characteristics of nano ZnO rods, such as I-V curve, aging process and focus performance, with that of carbon nanotube. From this comparison, it can be seen that the nano ZnO rods can be used as field emitters in a FED device
Carbon nanotube/mesoporous silica composites with controlled diameter and bundle size have been synthesized by using highly selective catalytic method. The composites were characterized by SEM and TEM. Results suggest that the bundle size, rather than the nanotube diameter or differences in work function, is more important in determining the field emission properties of SWNT/mesoporous silica composites...
Flower-like nanostructure zinc oxide (ZnO) whiskers have been fabricated on the patterned ITO electrodes with glass panel by a simple hydrothermal growth method. The field emission properties of the flower-like ZnO nano-whiskers have a low field emission threshold voltage (4 V at a current density of 0.1 mA/cm2) and a high current density 1 mA/cm2 at an applied field of 6 V/mum. The low temperature...
Gamma correction is an important process to realize the truthful transmission of the original image luminance. Gamma characteristic of the field emission display was analyzed. To reduce the errors between the actual gray level and the ideal one, a dynamic (look up table) LUT method based on the error diffusion algorithm of Floyd Steinberg is proposed, in which the rounding error of each pixel is diffused...
A new type under-gate field emission display (UGFED) panel has been discussed, in which a metal mask is mounted upper the cathode to obtain a low driving voltage and a good focus performance
Crosstalk may be introduced into field emission display by field infiltration besides beam dispersion. For line scanned, pulse width modulated FED, such crosstalk happens between adjacent pixels holding the same column electrode. Analysis result shows that enlarging electrode width or interval does not help much in eliminating electrically induced crosstalk. The proper method is to apply a small negative...
A basic triode structure of carbon nanotube field emission display was shown which has three electrode, anode, gate and cathode electrodes. A circuit model for the subpixel of the panel, the capacitance and resistance in the CNT-FED panel is evaluated. From the simulation using pspice, the decrease in the value of the capacitance, would reduce the rising and falling time of the driving voltage
A combined circuit model of both outer driving circuit and inner circuit is given for mode FED, normal structured or gate-substrated. Based on the model, anode voltage's effect on gate voltage is analyzed. Charging effect on driving signal may affect grayscale of figures. A structure is suggested to reduce such effect
In this paper, a novel phosphor coating method is proposed. We use an extra plate made by high impedance material as a barrier grid and spacer to block the electrons to bombard the neighbor pixels. Moreover, luminance efficiency of the FED panel is investigated by a circuit model with a suitable impedance value of the extra plate
On the assumption that the reflection coefficient series is a non-Gaussian, stationary and statically independent random process, ARMA model was introduced to solve the mixed phase seismic wavelet estimation. In this paper, a cumulant-based SVD-TLS (singular value decomposition and total least squares) algorithm with less computational price was employed. Numerical simulations demonstrate that the...
In the distributed video coding system, side-information takes an important role in reconstructing the Wyner-Ziv frames. To generate good side-information, we propose a new interpolation strategy based on motion estimation and motion compensation which exploits the video temporal redundancy. Besides, we propose a new framework based on the above strategy. In this framework, multi-estimation mode and...
We propose a new type of secure communication systems, called amorphous communication systems, in which the message is embedded in the statistics of the random pulse waveforms. We further apply the principle of statistical matched filters to construct an optimal receiver. We show how the system works and then analyze its performance based on density evolution and Gaussian approximation. We also compare...
One of UWB proposal in IEEE P802.15 WPAN project is to use OFDM system and punctured convolutional codes for UWB channels supporting data rate up to 480 Mb/s. We apply a TTCM encoder to examine the possible improvement for UWB/OFDM. We construct punctured parity-concatenated trellis codes in which a TCM code is used as the inner code and a simple parity-check code is used as the outer code. The bit...
In this paper, we first present several propositions which show how to find optimal pulses for UWB systems using PPM on Gaussian channels. The optimization has been done in term of minimizing bit error rate (BER) for a given modulation index. Using the new pulses the BER performance can be improved by 0.4-0.7 dB. Furthermore, numerical results show that similar performance improvement can be obtained...
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