Search - DDS - CodeBus

Search - DDS - List

[Post-TeleCom sofeware systems] BPSK Transmitter DL : 0: 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.
Date : 2011-03-18 Size : 30.65kb User : publicxz
[Post-TeleCom sofeware systems] wqdds0727 DL : 0: 用于的dsp builder的matlab实现算法，产生可编程的sin或cos波形，可以通过它作为ddc的dds-For the dsp builder of matlab algorithm, resulting in programmable waveform sin or cos can be as ddc the dds
Date : 2025-12-29 Size : 6kb User : wq
[Post-TeleCom sofeware systems] AD9954pdf DL : 0: AD9954是美国AD公司采用先进的DDS技术生产的高集成度频率合成器，它能产生200MHz的模拟正弦波。文章介绍了AD9954的基本特点和引脚功能，分析了其内部结构和工作原理，给出了AD9954在高速调制信号系统中的应用方案。-AD9954 is AD using advanced DDS technology to produce a high level of integration of the frequency synthesizer that can generate the analog sine wave 200MHz. This paper introduces the basic features of AD9954 and pin functions, an analysis of its internal structure and working principle, given the AD9954 high-speed modulation signal system applications.
Date : 2025-12-29 Size : 1.34mb User : zhanxiaohong
[Post-TeleCom sofeware systems] qam_64 DL : 0: 64QAM调制,采用硬件语言verilog实现,其中调用了DDS的IP核-64QAM modulation, using language verilog hardware implementation, which is called the IP core of the DDS
Date : 2025-12-29 Size : 1kb User : zhujing
[Post-TeleCom sofeware systems] DDS_32_half DL : 0: 使用MATLAB 实现得仅有一半存储量的DDS。-MATLAB to achieve half of the storage capacity of DDS
Date : 2025-12-29 Size : 1kb User : Miss Cheng