We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation, phase-shift keying, and pulse amplitude modulation communications systems.We study the performance of a standard CFO estimate, which consists of first raising the received signal to the Mth power, where M is an integer depending on the type and size of the symbol constellation, and then applying the nonlinear least squares (NLLS) estimation approach. At low signal-to noise ratio (SNR), the NLLS method fails to provide an accurate CFO estimate because of the presence of outliers. In this letter, we derive an approximate closed-form expression for the outlier probability. This enables us to predict the mean-square error (MSE) on CFO estimation for all SNR values. For a given SNR, the new results also give insight into the minimum number of samples required in the CFO estimation procedure, in order to ensure that the MSE on estimation is not significantly affected by the outliers.
标签： frequency-offset estimation quadrature amplitude
上传时间： 2014-01-22
上传用户：牛布牛
Carrier-phase synchronization can be approached in a general manner by estimating the multiplicative distortion (MD) to which a baseband received signal in an RF or coherent optical transmission system is subjected. This paper presents a unified modeling and estimation of the MD in finite-alphabet digital communication systems. A simple form of MD is the camer phase exp GO) which has to be estimated and compensated for in a coherent receiver. A more general case with fading must, however, allow for amplitude as well as phase variations of the MD. We assume a state-variable model for the MD and generally obtain a nonlinear estimation problem with additional randomly-varying system parameters such as received signal power, frequency offset, and Doppler spread. An extended Kalman filter is then applied as a near-optimal solution to the adaptive MD and channel parameter estimation problem. Examples are given to show the use and some advantages of this scheme.
标签： synchronization Carrier-phase multiplicativ approached
上传时间： 2013-11-28
上传用户：windwolf2000
In this paper, a new family of Cassinian wave-guides is proposed, simulating and calculation are finished with CST Microwave Studio that based on Finite Integral Technique (FIT), and some results are given. Electromagnetic field mode type of it is TE, electromagnetic field is stronger near neck region, and some resonance frequencies appear. The new Cassinian curve wave-guides will possess higher power than ones of the rectangular and elliptic wave-guides because the height at the position where maximal electric field occurs is smaller.
标签： calculation wave-guides simulating Cassinian
上传时间： 2014-01-18
上传用户：netwolf
FIST可堆叠文件系统，linux文件系统修改相关的开源软件，使得对linux文件系统功能的改进很简单了 The FiST (File System Translator) system combines two methods to solve the above problems in a novel way: a set of stackable file system templates for each operating system, and a high-level language that can describe stackable file systems in a cross-platform portable fashion. Using FiST, stackable file systems need only be described once. FiST s code generation tool, fistgen, compiles a single file system description into loadable kernel modules for several operating systems (currently Solaris, Linux, and FreeBSD). The project demonstrates that with FiST, code size and development time are reduced significantly, while imposing a small performance overhead of only 1-2％. These benefits are achieved, as well as portability, without changing existing operating systems or file system.
上传时间： 2014-01-10
上传用户：xsnjzljj
hanks for downloading this code. This VB Project shows you how to make forms with "rounded rectangle" shape. It also shows you how you can reduce the size of your programs with a GUI by using blocks of images and absolutely positioning and stretching them to create a dialog box, rather than making the whole dialog box in a graphics program and setting it as the Picture property of the Form. Another advantage of using image blocks is that you can resize this form to virtually any size and the effect will still be the same.
标签： downloading rectangle Project rounded
上传时间： 2013-12-13
上传用户：zhangliming420
Make a graph from database record and either send it to a printer directly selecting many print options or copy it in any file on disc. This project also gives you print preview option for A4 size paper and you can set your graph anywhere on the page.Also if you want to change graph s height or width you can change.Zooming effect is also given using hsrollbar.
标签： selecting database directly printer
上传时间： 2016-02-06
上传用户：s363994250
In this example we solve the following single ODE Program Name: RKG-1.FOR (Runge-Kutta-Gill algorithm, fixed step size)
标签： Runge-Kutta-Gill following example Program
上传时间： 2014-01-16
上传用户：maizezhen
Using Gaussian elimination to solve linear equations. // In this version, we allow matrix of any size. This is done by treating // the name of a 2-dimensional array as pointer to the beginning of the // array. This makes use of the fact that arrays in C are stored in // row-major order.
标签： elimination equations Gaussian version
上传时间： 2016-02-14
上传用户：hxy200501
Express DSP compliant C55x DTMF detector software is proposed in two versions: one with a 5 ms frame size and one with a 10 ms frame size. The versions are quite similar in behavior. The version with a 10 ms frame size is faster, but the overall quality is higher in the 5 ms version, due to lower time granularity. DTMF算法for TI DSP 54X/55X
标签： compliant detector software proposed
上传时间： 2016-02-15
上传用户：liuchee
Jpeg2000编解码器，附VC、Delphi等常用编程语言的使用例程 J2K-Codec ver 1.9 === === === === === === === === ===== Make your graphics look better with an easy-to-use JPEG 2000 decoding component. J2K-Codec can help game developers, screensaver creators and many others to improve their products--to achieve better image quality and reduce installation package size. The new image compression standard based on wavelet technology has many interesting features not available in the old JPEG, such as alpha-channel and varied resolution levels.
上传时间： 2013-12-27
上传用户：kytqcool
