Description: The basic parts of the BFSK transmitter are the preamble and the data input circuit. The preamble sequence is positioned in front of each packet of 122 bits for a total of 128 bits packet. The main purpose of the preamble is to facilitate the reception, providing both bit and packet synchronization. The data input circuit mainly consists from memory elements and a convolutional encoder with r=1/2. Thus, the input bits must be stored in a temporary memory and be partitioned in blocks of 61 bits. Then the convolutional encoder doubles the bits and adds two more trail bits at the end of the message. A multiplexer makes sure that that the correct sequence, choosing between preamble and encoded bit, is propagating to the next stage. The next stage of the transmitter consists of two direct digital synthesizers (DDS), and a multiplexer that is fed with zeros and ones to choose between the two frequencies. For each bit, we allow 64 samples of the respective frequency to be transmitted. Although the implementation of the selection between the two frequencies is strait forward, the enable port of the multiplexer should be used along with a Matlab Code (MCode) block in order to prevent the propagation of some initial undefined states during initialization. The only functionality of the MCode block is to enable the multiplexer after the first bit of the preamble is detected. Finally, pulse shaping is not used and the addition of a single filter after the last multiplexer would suffice to implement this functionality. Platform: |
Size: 31381 |
Author:publicxz |
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Description: 本书的目的主要是向读者展示傅里叶分析和小波的许多基础知识以及在信号分析方面的应用。全书分为8章和2个附录，前言部分是学习第1章至第7章的准备知识，即内积空间；第1章讲解傅里叶系列的基础知识；第2章讲解傅里叶变换；第3章介绍离散傅里叶变换以及快速傅里叶变换；第4章至第7章讨论小波，重点在于正交小波的构建；附录部分则介绍稍微复杂的一些技术主题以及演示概念或产生图形的MATLAB代码。许多关于小波的文章和参考书籍均要求读者具有复杂的数学背景知识，本书则只要求学生具有较好的微积分以及线性代数知识，通俗易懂，是数学、计算机、电子、通信、地质、医学、机械等专业高年级本科生及研究生的基础教科书，也可作为相关技术人员的参考书。-The main purpose of this book is to show readers Fourier and wavelet analysis of many of the basic knowledge as well as in signal analysis applications. The topics are divided into eight chapters and two appendices, is to learn from the preamble of Chapter 1 to Chapter 7 of the preparation of knowledge, that is, inner product space Chapter 1 on the basis of Fourier series of knowledge Chapter 2 on Fourier Transform Chapter 3 introduced the Discrete Fourier Transform and Fast Fourier Transform Chapter 4 to Chapter 7 to discuss wavelet, with emphasis on construction of orthogonal wavelet appendix describes slightly complex themes, as well as a number of technical concepts or produce demo MATLAB graphics code Platform: |
Size: 13749248 |
Author:刘宏 |
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Description: this code is for Wimax(ieee standard 802.16) and other ofdm based transmitter and makes preamble for their training frames to make synchronization easier. Platform: |
Size: 1024 |
Author:amin |
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Description: 本代码可产生ZCZ序列，应用于同步码和导频码，具有很好的自相关性，应用环境matlab-This code can be generated ZCZ sequence applied preamble and pilot symbols, with good autocorrelation, application environment matlab Platform: |
Size: 1024 |
Author:辛永超 |
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