Posted on Category:计算机代写

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 计算机代写|自适应算法代写Cooperative and Adaptive Algorithms代考|Channel Equalization

As can be seen from Fig. 2.13, channel equalization or inverse filtering consists of estimating a transfer function to compensate for the linear distortion caused by the channel. From another point of view, the objective is to force a prescribed dynamic behavior for the cascade of the channel (unknown system) and the adaptive filter, determined by the input signal. The first interpretation is more appropriate in communications, where the information is transmitted through dispersive channels $[33,38]$. The second interpretation is appropriate for control applications, where the inverse filtering scheme generates control signals to be used in the unknown system [28].

In the ideal situation, where $n(k)=0$ and the equalizer has sufficient order, the error signal is zero if
$$W(z) H(z)=z^{-L}$$
where $W(z)$ and $H(z)$ are the equalizer and unknown system transfer functions, respectively. Therefore, the ideal equalizer has the following transfer function
$$W(z)=\frac{z^{-L}}{H(z)}$$

## 计算机代写|自适应算法代写Cooperative and Adaptive Algorithms代考|Digital Communication System

For illustration, a general digital communication scheme over a channel consisting of a subscriber line (telephone line, for example) is shown in Fig. 2.15. In either end, the input signal is first coded and conditioned by a transmit filter. The filter shapes the pulse and limits in band the signal that is actually transmitted. The signal then crosses the hybrid to travel through a dual duplex channel. The hybrid is an impedance bridge used to transfer the transmit signal into the channel with minimal leakage to the near-end receiver. The imperfections of the hybrid cause echo that should be properly cancelled.

In the channel, the signal is corrupted by white noise and crosstalk (leakage of signals being transmitted by other subscribers). After crossing the channel and the far-end hybrid, the signal is filtered by the receive filter that attenuates highfrequency noise and also acts as an antialiasing filter. Subsequently, we have a joint DFE and echo canceller, where the forward filter and echo canceller outputs are subtracted. The result after subtracting the decision feedback output is applied to the decision device. After passing through the decision device, the symbol is decoded.
Other schemes for data transmission in subscriber line exist [33]. The one shown here is for illustration purposes, having as special feature the joint equalizer and echo canceller strategy. The digital subscriber line (DSL) structure shown here has been used in integrated services digital network (ISDN) basic access that allows a data rate of $144 \mathrm{Kbits} / \mathrm{s}$ [33]. Also, a similar scheme is employed in the high bit rate digital subscriber line (HDSL) $[32,40]$ that operates over short and conditioned loops $[41,42]$. The latter system belongs to a broad class of digital subscriber line collectively known as XDSL.

In wireless communications, the information is transported by propagating electromagnetic energy through the air. The electromagnetic energy is radiated to the propagation medium via an antenna. In order to operate wireless transmissions, the service provider requires authorization to use a radio bandwidth from government regulators. The demand for wireless data services is more than doubling each year leading to foreseeable spectrum shortage in the years to come. As a consequence, all efforts to maximize the spectrum usage is highly desirable and for sure the adaptive filtering techniques play an important role in achieving this goal. Several examples in the book illustrate how the adaptive filters are employed in many communication systems so that the readers can understand some applications in order to try some new they envision.

## 计算机代写|自适应算法代写Cooperative and Adaptive Algorithms代考|Channel Equalization

$$W(z) H(z)=z^{-L}$$

$$W(z)=\frac{z^{-L}}{H(z)}$$

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。