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.
This paper examines the asymptotic (large sample) perFormance
of a family of non-data aided feedforward (NDA FF) nonlinear
least-squares (NLS) type carrier frequency estimators for burst-mode
phase shift keying (PSK) modulations transmitted through AWGN and
flat Ricean-fading channels. The asymptotic perFormance of these estimators
is established in closed-Form expression and compared with the
modified Cram`er-Rao bound (MCRB). A best linear unbiased estimator
(BLUE), which exhibits the lowest asymptotic variance within the family
of NDA FF NLS-type estimators, is also proposed.
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.
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.
16 relay output channels and 16 isolated digital input channels
LED indicators to show activated relays
Jumper selectable Form A/Form B-type relay output channel
Output status read-back
Keep relay output values when hot system reset
High-voltage isolation on input channels(2,500 VDC)
Hi ESD protection(2,00VDC)
High over-voltage protection(70VDC)
Wide input range(10~50VDC)
Interrupt handling capability
High-density DB-62 connector
Board ID
This document represents the first stage in a process of taking the National Strategy for Police InFormation Systems (NSPIS) forward. It defines the mechanisms to ensure that we (and our partners) have access to the right inFormation, in the right Form, in the right time at an appropriate cost. The Strategy will ensure the Police Service has a collective understanding of the value of inFormation and that we are able to exploit National InFormation Assets in support of local policing.
javascript中文教程
<INPUT
TYPE="button"
NAME="objectName"
VALUE="buttonText"
[onClick="handlerText"]>
NAME specifies the name of the button object as a property of the enclosing Form object and can be accessed using the name property. VALUE specifies the label to display on the button face and can be accessed using the value property.
LiScNLS is a Matlab application for the numerical study of some nonlinear
differential equations of the Form Lu=Nu, using the Lyapunov-Schmidt method.
Downloading the LiScNLS package creates a new LiScNLS folder on the computer.
