### 电子工程代写|数字信号处理代写Digital Signal Processing代考|ELEC3104

statistics-lab™ 为您的留学生涯保驾护航 在代写数字信号处理Digital Signal Processing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信号处理Digital Signal Processing方面经验极为丰富，各种代写数字信号处理Digital Signal Processing相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• (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

## 电子工程代写|数字信号处理代写Digital Signal Processing代考|Need for Advancement in Wireless Technologies

The performance metrics such as packet loss, throughput and delay of WiMAX are measured on the basis of optimal boundary per WiMAX cell under different WiMAX network models. The performance metrics considered are spectral efficiency, throughput, transmit power, percentage of successful links, PAPR, BER.

SNR and CINR. This chapter mainly focusses on spectrum sensing techniques to achieve better spectral efficiency [5].

Recently, there is a lot of demand for tremendous technologies such as 3G, 4G and $5 \mathrm{G}$, where voice-only communications are transitioned into multimedia type applications $[6,7]$. These applications may be mobile TV, mobile P2P, streaming multimedia, video games, video monitors, interactive video, 3D services and video sharing. These high data rate applications consume more and more energy to guarantee quality of service [8]. However, the current frequency allocation schemes are unable to handle the requirements of recent higher data rate systems due to the limitations of the frequency spectrum.

Therefore, more efforts are kept on efficient frequency spectrum usage, and then a solution is found by Joseph Mittola [9], in the name of cognitive radio. The basic definition given by him is that cognitive radio (CR) is a type of a transceiver which can intelligently sense or detect unusable communication channel, and instantly allocate those channels to the unlicensed users without disturbing occupied channels [10]. Though there is no formal meaning of cognitive radio, various definitions can be seen in several contexts. A cognitive radio is, as defined by the researchers at Virginia Tech, ‘A software defined radio with a cognitive engine brain’ [11, 12]. The evolution of SDR in current technologies is provided in Fig. 2. The physical, data link and network layers of OSI model can be implemented by using SDR as shown in Fig. 3. The SDR Forum proposed a multi-tiered definition of SDR by providing the use of open architectures for advanced wireless systems and supports deployment and development [13-15]. An abstraction of the five-tier definition is illustrated in Fig. 4, where the length of the arrow represents the distribution of the software content within the radio [16].

Software-defined radio architecture comprises three sections such as radio frequency (RF), intermediate frequency (IF) and baseband section [17, 18]. It is observed from Fig. 5 that an RF signal received by smart antenna is sent to the hardware (here USRP) in which various components are inbuilt such as daughterboard, ADC/DAC, FPGAs, DSPs and ASICs. This hardware converts RF signal to IF signal and then to low-frequency baseband signal (digitized) and that will be sent to a personal computer (PC) for baseband signal processing in the transmitter (Tx) path. In this experimentation, an open-source software, GNU Radio, is employed as a software to perform baseband processing in which most of the signal processing blocks are inbuilt. All the reverse operations are performed in receiver (Rx) path such that baseband signal is converted to analogue by DAC and then sent into the air by RF hardware.

## 电子工程代写|数字信号处理代写Digital Signal Processing代考|Results and Discussion

Generally, energy detection performance is measured in terms of probability of false alarm $P_{f a}$ (detection algorithm falsely decides that $\mathrm{PU}$ is present when it actually is absent) and probability of detection $P_d$ (correctly detecting the PU signal). Mathematically, $P_{f a}$ and $P_d$ can be expressed as [16]:
\begin{aligned} &P_{f a}=P_r\left(\text { signal is detectedl } H_0=P_r\left(u>\lambda \mid H_0\right)=\int_\lambda^{\infty} f\left(u \mid H_0\right) d u\right. \ &P_d=P_r \text { (signal is detected } H_1=P_r\left(u>\lambda \mid H_1\right)=\int_\lambda^{\infty} f\left(u \mid H_1\right) d u \end{aligned}
where $f\left(u \mid H_i\right.$ ) denotes the probability density function (pdf) of test statistic under hypothesis $H_i$ with $i=0,1$.

Thus, we target at maximizing $P_d$ while minimizing $P_{f a} . P_d$ versus $P_{f a}$ plot depicts receiver operating characteristics (ROC) and is considered as an important performance indicator. The receiver operating characteristics $(\mathrm{ROC})$ for various number of sensing samples, such as 10,50, 100 and 200, are presented in Fig. 7a, b, c and d, respectively [16]. It can be observed from Fig. 7 that the probability of detection $\left(p_d\right)$ is increased with the number of sensing samples. In our simulations, some assumptions are made such as the primary signal is deterministic, and noise is real Gaussian with mean 0 and variance 1 [17]. The probability of detection for Rayleigh channel is calculated by the averaging the probability of detection for AWGN channel [18].

## 电子工程代写|数字信号处理代写Digital Signal Processing代考|Need for Advancement in Wireless Technologies

WiMAX 的丢包率、吞吐量和延迟等性能指标是在不同WiMAX 网络模型下每个WiMAX 小区的最佳边界的基础上测量的。考虑的性能指标是频谱效率、吞吐量、发射功率、成功链接的百分比、PAPR、BER。

SNR 和 CINR。本章主要关注频谱感知技术，以实现更好的频谱效率[5]。

## 电子工程代写|数字信号处理代写Digital Signal Processing代考|Results and Discussion

$P_{f a}=P_r\left(\right.$ signal is detectedl $H_0=P_r\left(u>\lambda \mid H_0\right)=\int_\lambda^{\infty} f\left(u \mid H_0\right) d u \quad P_d=P_r$ (signal is

## 广义线性模型代考

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## 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。