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
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.
标签： performance asymptotic examines non-data
上传时间： 2015-12-30
上传用户：225588
We present a particle filter construction for a system that exhibits time-scale separation. The separation of time-scales allows two simplifications that we exploit: i) The use of the averaging principle for the dimensional reduction of the system needed to solve for each particle and ii) the factorization of the transition probability which allows the Rao-Blackwellization of the filtering step. Both simplifications can be implemented using the coarse projective integration framework. The resulting particle filter is faster and has smaller variance than the particle filter based on the original system. The convergence of the new particle filter to the analytical filter for the original system is proved and some numerical results are provided.
标签： construction separation time-scale particle
上传时间： 2016-01-02
上传用户：fhzm5658
Resampling is the operation of converting from audio represented at one sampling rate to a representation at another sample rate with minimum losses.
标签： represented Resampling converting operation
上传时间： 2013-12-24
上传用户：moshushi0009
NAME Control_AT24Cxx This collection of routines allows an AT89C2051 microcontroller to read and write the AT24Cxx family of serial CMOS EEPROMS. This version of the code is compatible only with the AT89C2051 due to the location of the data buffer and stack in RAM. The code may be modified to work with the AT89C1051 by relocating or resizing the buffer and stack to fit into the smaller amount of RAM available in the AT89C1051. Note that the minimum size of the buffer is determined by the page size of the AT24Cxx.
标签： microcontroller Control_AT collection routines
上传时间： 2013-12-13
上传用户：asddsd
The Funambol J2ME Mail Client aims to be a light, easy to use, free email client for J2ME devices. The first release comes with a simple but effective UI, and a storage limited to the internal RMS only. This makes the application compatible with most of the phones around (minimum requirements are: MIDP2.0, CLDC 1.0, 512k of Storage). The mail synchronization using SyncML 1.2 over HTTP, thus removing any problem related to the access to IMAP or POP ports. The mail client synchonizes its address book with the one on the server, Its design is modular and can be extended in future with other mail protocols, a more sophisticated UI and access to the phone s AddressBook or filesystem for the devices allowing this. See the javadoc for more information on the structure of the library.
标签： J2ME Funambol devices Client
上传时间： 2014-01-05
上传用户：gououo
When working with mathematical simulations or engineering problems, it is not unusual to handle curves that contains thousands of points. Usually, displaying all the points is not useful, a number of them will be rendered on the same pixel since the screen precision is finite. Hence, you use a lot of resource for nothing! This article presents a fast 2D-line approximation algorithm based on the Douglas-Peucker algorithm (see [1]), well-known in the cartography community. It computes a hull, scaled by a tolerance factor, around the curve by choosing a minimum of key points. This algorithm has several advantages: 这是一个基于Douglas-Peucker算法的二维估值算法。
标签： mathematical engineering simulations problems
上传时间： 2013-12-20
上传用户：changeboy
// // Histogram Sample // This sample shows how to use the Sample Grabber filter for video image processing. // Conceptual background: // A histogram is just a frequency count of every pixel value in the image. // There are various well-known mathematical operations that you can perform on an image // using histograms, to enhance the image, etc. // Histogram stretch (aka automatic gain control): // Stretches the image histogram to fill the entire range of values. This is a "point operation," // meaning each pixel is scaled to a new value, without examining the neighboring pixels. The // histogram stretch does not actually require you to calculate the full histogram. The scaling factor // is calculated from the minimum and maximum values in the image.
标签： Sample Histogram Grabber sample
上传时间： 2013-12-15
上传用户：ryb
北京大学ACM比赛题目 Consider an infinite full binary search tree (see the figure below), the numbers in the nodes are 1, 2, 3, .... In a subtree whose root node is X, we can get the minimum number in this subtree by repeating going down the left node until the last level, and we can also find the maximum number by going down the right node. Now you are given some queries as "What are the minimum and maximum numbers in the subtree whose root node is X?" Please try to find answers for there queries.
标签： the Consider infinite numbers
上传时间： 2013-12-16
上传用户：日光微澜
KMEANS Trains a k means cluster model.CENTRES = KMEANS(CENTRES, DATA, OPTIONS) uses the batch K-means algorithm to set the centres of a cluster model. The matrix DATA represents the data which is being clustered, with each row corresponding to a vector. The sum of squares error function is used. The point at which a local minimum is achieved is returned as CENTRES.
标签： CENTRES KMEANS OPTIONS cluster
上传时间： 2014-01-07
上传用户：zhouli
