Description: 脉冲编码调制（PCM）用于在数字传输媒体上传送模拟信号，在PCM中，首先对模拟信号以高于其带宽两倍的奈奎斯特率进行采样，然后对所得样本进行量化。采用不同量化级别生成的PCM编码会影响接收器重建模拟信号的质量。 -Pulse code modulation (PCM) for the media in the digital transmission of analog signal transmission in the PCM, the first analog signal to more than the Nyquist rate of twice the bandwidth sample, and then to quantify the samples. Using different quantization level generated PCM coding receiver will affect the quality of the reconstruction of analog signals. Platform: |
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Author:jack |
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Description: 摘 要
文章以空间监控系统为背景,深入研究了JPEG图像压缩标准的实现方法,并基于FPGA对其进行了实现和优化。文中给出了详细的实现方法和优化过程,测试表明达到了很好的效果。
简单介绍了有损静态图像压缩当前有两种比较流行的标准JPEG和JPEG2000。说明了用JPEG方法压缩的原因。
介绍JPEG基本原理：JPEG对灰度图像的压缩处理过程主要包括:图像分割,离散余弦变换(DCT),量化(Quantization),“Z”形排序(Zigzag Scan),差分脉冲编码调制(Differential Pulse Code Modulation,DPCM)对直流系数(DC),行程长度编码(Run-Length Encoding,RLE)对交流系数(AC),霍夫曼(Huffman)编码等。
JPEG标准的特点是离散余弦变换。
比较详细介绍压缩系统的构成和实现。实现提及步骤， JPEG压缩模块设计和编码模块实现细节。
-Abstract
Article in the space monitoring system for the background, in-depth study of the JPEG image compression standard implementation methods and carried out based on FPGA implementation and optimization. In this paper, a detailed method of implementation and optimization of the process, testing showed that to achieve good results.
Easy introduction of harmful static image compression has two kinds of comparisons that the current popular standard JPEG and JPEG2000. Illustrated by the reasons for JPEG compression method.
JPEG introduce the basic principles: JPEG compression of gray-scale image processing include: image segmentation, discrete cosine transform (DCT), quantization (Quantization), "Z"-shaped sort (Zigzag Scan), differential pulse code modulation (Differential Pulse Code Modulation, DPCM) on the DC coefficient (DC), Run Length Encoding (Run-Length Encoding, RLE) of the exchange coefficient (AC), Hoffman (Huffman) coding.
JPEG standard is characterized by discrete Platform: |
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Author:压子 |
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Description: ，用MATLAB实现快跳频通信系统的仿真。主要应用了SIMULINK和COMMUNICATION BLOCKETS两个模块。整个设计包括了信源产生部分、发送部分、跳频调制部分、信道部分、接收部分和结果分析部分共六个模块，核心技术是伪随机序列的产生和频率合成器的设计，而关键技术是收发两端的伪随机码元的同步。伪随机码的产生用S－函数编程来开发自己的SIMULINK模块。同步的实现是收发两端采用相同的扩频脉冲触发。而且在设计中每个模块都采用了模块封装技术，从而简化了框图结构-Using MATLAB to achieve fast frequency-hopping communication system simulation. The main use of SIMULINK and COMMUNICATION BLOCKETS two modules. The whole design, including part of the generated source, sending part of some frequency-hopping modulation, channel of the receiving part and the results of analysis of part of a total of six modules, the core technology is the emergence of pseudo-random sequence and frequency synthesizer design, and the key technology is the transceivers at both ends of the pseudo-random synchronization symbol. Pseudo-random code generated by S-function programming to develop their own modules SIMULINK. Synchronization is used to send and receive ends of the same spread-spectrum pulse trigger. But also in the design of each module using the module packaging technology, which simplifies the structure of the diagram Platform: |
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Author:笑笑生 |
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Description: 【摘要】采用’()*(+ 通信仿真软件对应用于无线信道中的,-./，0-./，01(’ 的数字通
信方式和主要通信过程的实际情况进行计算机模拟仿真。主要通信过程为抽样、量化、编码、调制解
调、纠错编码等，并给出了几种调制解调的主要特性，为建立实际通信系统提供了基本的依据。
【关键词】移相键控（-./）；正交幅度调制（1(’）；脉码调制（-2’）-【Abstract】 ()*(+ communication simulation software used in wireless channel in ,-./, 0-. /, 01 ( the number of pass
Letter mode and the actual situation of the main communication process by computer simulation. Main communication process as sampling, quantization, coding, modulation solution
Transfer, error correction coding, etc., and gives the main features of several modulation and demodulation, in order to establish the actual communications system provides the basic basis.
Key words (-./) phase shift keying quadrature amplitude modulation (1 ( ) pulse code modulation (-2 ) Platform: |
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Author:yanyan |
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Description: 脉冲编码调制(PCM)实现
编程实现PCM技术的三个过程：采样、量化与编码。
采样：低通连续信号采样，以 x=sin(200*t) m=x./(200*t) m=m.*m 为例说明低通采样定理，绘出信号时、频图形；带通连续信号采样，以x=sin(20*t) m=x./t 为例说明带通采样定理，绘出信号时、频图形。
量化：均匀量化，以幅度 的正弦信号为例实现为64级电平的均匀量化；非均匀量化，输入A律PCM编码器的正弦信号 ，采样序列为 ，将其进行PCM编码，给出编码器的输出码组序列
编码：以上述信号为例，实现A律的13折线近似法及国际标准PCM对数A律量化编码。-Pulse code modulation (PCM) to achieve
PCM technology programming three processes: sampling, quantization and coding.
Sample: low-pass continuous signal sampling to x = sin (200* t) m = x./(200* t) m = m.* m an example low-pass sampling theorem, draw the signal, frequency graphics bandpass sampling continuous signals to x = sin (20* t) m = x./t an example bandpass sampling theorem, draw the signal, frequency graph.
Quantization: uniform quantization, in order to realize the magnitude of sinusoidal signal as an example for the 64 level uniform quantization non-uniform quantization, input A law PCM encoder sine signal, the sampling sequence, to be PCM encoded, the encoder is given The output code sequence
Code: A Case Study of the signal to achieve the 13 A line approximation law and international standards on the number of A law PCM coding quantization. Platform: |
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Author:马芳 |
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Description: 利用Matlab仿真脉冲编码调制（PCM）及A律、μ律PCM对声音进行压缩编解码过程。
脉冲编码调制（PCM，Pulse Code Modulation）是一种将模拟语音信号转换成数字信号的编码方式。波形编码器的作用是对采样后的信号样本进行量化和编码。从数学上来看，量化过程就是把一个连续幅度值的无限数集合映射成一个离散幅度值的有限数集合，编码就是用一组二进制数来表示这些映射后的有限数。国际标准化的PCM采用折叠二进制码，符合长途电话质量。根据量化方法的不同，PCM可分为均匀量化PCM和对数PCM两大类，对数PCM中，2Aμ律和律编码都已被定为国际标准。-Matlab simulation using pulse code modulation (PCM) and the A law, μ law PCM codec for voice compression process.
Pulse Code Modulation (PCM, Pulse Code Modulation) is an analog voice signal into digital signal encoding. The role of the encoder waveform is sampled signal sample quantization and coding. From the mathematical point of view, the process is to quantify the magnitude of the value of a continuous set of infinite number of maps into a finite number of discrete set of amplitude values , encoding is to use a set of binary digits, said after a limited number of these maps. By folding the International Standardization of PCM binary code, in line with long-distance telephone quality. According to the different quantitative methods, PCM can be divided into uniform quantization PCM PCM and the number of two categories, on the number of PCM in, 2Aμ law and legal codes have been designated as international standards. Platform: |
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Author:tanii |
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Description: 已调制信号计算其普相关密度，仿真效果非常好，LDPC码的完整的编译码，包括调制，解调，信噪比计算，现代信号处理中谱估计在matlab中的使用，有CDF三角函数曲线/三维曲线图，线性调频脉冲压缩的Matlab程序,进行波形数据分析。- Modulated signals to calculate its density Pu-related, Simulation of the effect is very good, Complete codec LDPC code, Includes the modulation, demodulation, signal to noise ratio calculation, Modern signal processing used in the spectral estimation in matlab, There CDF trigonometric curve/3D graphs, LFM pulse compression of the Matlab program, Waveform data analysis. Platform: |
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Author:mmfivnvu |
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Description: 相参脉冲串复调制信号，窗函数法设计一个数字带通FIR滤波器，内含心电信号数据及运用MATLAB写的源代码。- Complex modulation coherent pulse train signal, A window function design FIR digital band-pass filter, ECG data and includes source code written in MATLAB. Platform: |
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Author:丁帆 |
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Description: 内含心电信号数据及运用MATLAB写的源代码，用于信号特征提取、信号消噪，相参脉冲串复调制信号。- ECG data and includes source code written in MATLAB, For feature extraction, signal de-noising, Complex modulation coherent pulse train signal. Platform: |
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Author:gan |
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Description: Implementation and Signal to Quantize noise ratio (SQNR) in Pulse code modulation using Matlab. Also compared A-law, u-law, companding.-Implementation and Signal to Quantize noise ratio (SQNR) in Pulse code modulation using Matlab. Also compared A-law, u-law, companding. Platform: |
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Author:ajay |
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