Abstract-The effect of the companding process on QAM signals has been under investigation for the past several years. The compander, included in the PCM telephone network to improve voice performance, has an unusual affect on digital QAM data signals which are transmitted over the same channel. The quantization noise, generated by the companding process which is multiplicative (and asymmetric), degrades the detectability performance of the outermost points of the QAM constellation more than that of the inner points. The combined effect of the companding noise and the inherent white gaussian noise of the system, leads us to a re-examination of signal constellation design. In this paper we investigate the detectability performance of a number of candidates for signal constellations including, a typical rectangular QAM constellation, the same constellation with the addition of a smear-desmear operation, and two new improved QAM constellation designs with two-Dimensional warpi
标签： investigation Abstract-The companding the
上传时间： 2013-12-20
上传用户：英雄
The OpenGL graphics system is a software interface to graphics hardware. (The GL stands for Graphics Library.) It allows you to create interactive programs that produce color images of moving three-Dimensional objects.
标签： graphics The interface Graphics
上传时间： 2013-11-27
上传用户：Altman
外国人开发的电磁时域有限差分方法工具包 Electromagnetic Finite-Difference Time-Domain (EmFDTD) is a basic two-Dimensional FDTD code developed at the School of Electrical Engineering, Sharif University of Technology. This code has been written based on the standard Yee s FDTD algorithm. Applications include propagation, scattering, and diffraction of electromagnetic waves in homogeneous and non-homogeneous isotropic media for in-plane propagating waves. Negative permittivites or permeabilities as well as dispersion is not included. Zero, Periodic, and Perfectly Matched Layer boundary conditions may be selectively applied to the solution domain. The program is best suited for study of propagation and diffraction of electromagnetic waves in Photonic Crystal structures. EmFDTD is written in MATLAB language and has been tested under MATLAB 5.0 and higher versions.
标签： Finite-Difference Electromagnetic two-dimensio Time-Domain
上传时间： 2014-11-24
上传用户：watch100
We describe and demonstrate an algorithm that takes as input an unorganized set of points fx1 xng IR3 on or near an unknown manifold M, and produces as output a simplicial surface that approximates M. Neither the topology, the presence of boundaries, nor the geometry of M are assumed to be known in advance — all are inferred automatically from the data. This problem naturally arises in a variety of practical situations such as range scanning an object from multiple view points, recovery of biological shapes from two-Dimensional slices, and interactive surface sketching.
标签： demonstrate unorganized algorithm describe
上传时间： 2013-12-18
上传用户：xc216
Range imaging offers an inexpensive and accurate means for digitizing the shape of three-Dimensional objects. Because most objects self occlude, no single range image suffices to describe the entire object. We present a method for combining a collection of range images into a single polygonal mesh that completely describes an object to the extent that it is visible from the outside.
标签： three-dimensiona inexpensive digitizing accurate
上传时间： 2016-11-29
上传用户：yxgi5
This MATLAB M-file implements the finite-difference time-domain solution of Maxwell s curl equations over a one-Dimensional space lattice comprised of uniform grid cells.
标签： finite-difference time-domain implements equations
上传时间： 2014-01-11
上传用户：270189020
A cylindrical wave expansion method is developed to obtain the scattering field for an ideal two-Dimensional cylindrical invisibility cloak. A near-ideal model of the invisibility cloak is set up to solve the boundary problem at the inner boundary of the cloak shell. We confirm that a cloak with the ideal material parameters is a perfect invisibility cloak by systematically studying the change of the scattering coefficients from the near-ideal case to the ideal one. However, due to the slow convergence of the zeroth order scattering coefficients, a tiny perturbation on the cloak would induce a noticeable field scattering and penetration.
标签： cylindrical scattering expansion developed
上传时间： 2017-03-30
上传用户：lhc9102
The frequency domain plays an important role in image processing to smooth, enhance, and detect edges of images. Although image data typically does not include imaginary values, the fast Fourier transform (FFT) has been used for obtaining spectra. In this paper, the fast Hartley transform (FHT) is used to transform two-Dimensional image data. Because the Hartley transform is real valued, it does not require complex operations. Both spectra and autocorrelations of two-Dimensional ultrasound images of normal and abnormal livers were computed.
标签： processing frequency important enhance
上传时间： 2014-01-08
上传用户：1051290259
Face Transfer is a method for mapping videorecorded perfor-mances of one individual to facial animations of another. It extracts visemes (speech-related mouth articulations), expressions, and three-Dimensional (3D) pose from monocular video or 铿乴m footage.
标签： videorecorded perfor-mances individual Transfer
上传时间： 2014-01-11
上传用户：2467478207
C Algorithms for Real-Time DSP Chapter 4 covers the basic real-time filtering techniques which are the cornerstone of one-Dimensional real-time digital signal processing.
标签： Algorithms techniques Real-Time filtering
上传时间： 2013-12-11
上传用户：lhc9102
