assignmentutor-lab™ 为您的留学生涯保驾护航 在代写数字系统设计Digital System Design方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写数字系统设计Digital System Design方面经验极为丰富，各种代写数字系统设计Digital System Design相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 电气工程代写|数字系统设计作业代写Digital System Design代考|Multipath Losses

Whenever a signal is sent out in space, the signal can either travel on a direct path from the transmitter antenna to the receiver antenna or take multiple indirect paths caused by reflections off objects, which is known as multipath. The most direct path the signal can take has the least amount of attenuation. The other paths (or multipath) are attenuated but can interfere with the direct path at the receiver. It is similar to a pool table, where you can hit a ball by aiming directly at the pocket or you can bank it off the table with the correct angle to the pocket. If both balls are in motion, they may interfere with each other at the input to the pocket (Figure 1-8).

The problem with multipath is that the signal takes both paths and interferes with itself at the receiving end. The reflected path has a reflection coefficient that determines the phase and the amplitude of the reflected signal, which can be different from the direct path. Also, the reflected path length is longer, which produces a signal with a different phase. If the phase of the reflected path is different, for example, $180^{\circ}$ out of phase from the direct path, and the amplitudes are the same, then the signal is canceled out and the receiver sees very little to no signal.

Fortunately, most of the time the reflected path is attenuated, since it is generally a longer path length than the direct path. Also, the level of the multipath depends on the reflection coefficient and the type of multipath. It does not completely cancel out the signal but can alter the amplitude and phase of the direct signal. The effect of multipath can cause large variations in the received signal strength. Consequently, multipath can affect coverage and accuracy where reliable amplitude or phase measurements are required. A further discussion on multipath is presented in Chapter 7 . The losses are as follows:
$L_{\text {multi }}=$ losses due to multipath cancellation of the direct path signal (in dB)
This loss is generally hard to quantize, since there are many variables and many potential paths. Thus, the analysis of the amount of loss that is used is associated with a probability number (see Chapter 7). Multipath is constantly changing, and certain conditions can adversely affect the coverage and the phase measurement accuracy. This loss is also a direct attenuation: a $1 \mathrm{~dB}$ loss equals a $1 \mathrm{~dB}$ loss in the link analysis. Careful positioning or siting of the antennas in a given environment is the most effective way to reduce the effects of multipath. Also, blanking methods to ignore signals received after the desired signal for long multipath returns are often used to help mitigate multipath. And finally, antenna diversity is another method to reduce multipath.

## 电气工程代写|数字系统设计作业代写Digital System Design代考|Receiver Antenna Losses

Antenna losses for the receiver are very similar to those for the transmitter, some of which are listed as follows:

• $L_{r r}$, radome losses on the receiver antenna. The radome is the covering over the antenna that protects the antenna from the outside elements.
• $L_{r p o l}$, polarization loss. Many antennas are polarized (i.e., horizontal, vertical, or circular). This defines the spatial position or orientation of the electric and magnetic fields.
• $L_{r f o c}$, focusing loss or refractive loss. This is a loss caused by imperfections in the shape of the antenna, so that the energy is focused toward the feed. This is often a factor when the antenna receives signals at low elevation angles.
• $L_{r p o i n t}$, mispointed loss. This is caused by transmitting and receiving directional antennas that are not exactly lined up and pointed toward each other. Therefore, the gains of the antennas do not add up without a loss of signal power. Note that this loss may be combined into one number so that it is not included in both the receiver analysis and the transmitter analysis.
• $L_{\text {rcon }}$, conscan crossover loss. This loss is present if the antenna is scanned in a circular search pattern.

The total losses for the receiver antenna can be calculated by adding all of the losses together, assuming that their values are in $\mathrm{dB}$ :
$$L_{r a}=L_{r r}+L_{r p o l}+L_{r f o c}+L_{r p o i n t}+L_{r c o n}$$
This total loss, as was the case in the transmitter section, is a direct attenuation of the signal: a $1 \mathrm{~dB}$ loss equals a $1 \mathrm{~dB}$ loss in the analysis.

# 数字系统设计代考

## 电气工程代写|数字系统设计作业代写Digital System Design代考|Receiver Antenna Losses

• 大号rr，接收天线上的天线罩损耗。天线罩是天线上的覆盖物，可保护天线免受外部元件的影响。
• 大号rp○l，极化损耗。许多天线是极化的（即水平、垂直或圆形）。这定义了电场和磁场的空间位置或方向。
• 大号rF○C，聚焦损失或屈光损失。这是由天线形状缺陷引起的损耗，因此能量集中在馈源上。当天线以低仰角接收信号时，这通常是一个因素。
• 大号rp○一世n吨，误点损失。这是由于发射和接收定向天线未完全对齐并相互指向造成的。因此，天线的增益不会在没有信号功率损失的情况下相加。请注意，此损耗可以合并为一个数字，因此它不包括在接收器分析和发射器分析中。
• 大号rcon , conscan 交叉损失。如果以圆形搜索模式扫描天线，则会出现这种损耗。

## 有限元方法代写

assignmentutor™作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## 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。

assignmentutor™您的专属作业导师
assignmentutor™您的专属作业导师