Description: 一个音频滤波器的C++类，可以实现低通，高通滤波，并可以指定频率，带宽和增益值-An audio filter C++ Category, you can realize low-pass, high pass filter, and can specify the frequency, bandwidth and gain value Platform: |
Size: 2048 |
Author:cxcxcx |
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Description: 电缆遥测传输是测井系统传输数据的主要方式。针对测井电缆传输速率低、 带宽窄等瓶颈问题 ,提出应用
ADSL 宽带网络接入的离散多音频调制(DMT)技术进行电缆传输的调制和解调 ,从理论上对此技术进行了详细分析 ,并
通过计算机仿真试验 ,证明该方法对于提高电缆的频带利用率是可行的。-Cable telemetry transmit is a main way of data transmission in well logging systems. In this paper , due to a variety
of shortcoming of logging cable , such as low transmit speed and narrow bandwidth , a DMT technology with the
application of ADS L wide band is presented. This technology is analyzed theoretically in detail , and it has been proved
that this method is feasible in increasing the bandwidth using efficiency of the cable by compute emulation. Platform: |
Size: 367616 |
Author:秦赵真 |
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Description: 水声通信面临的最困难的问题是多途干扰,其中自多途引起接收信号的幅度衰落,互多途引起接收信号的码间干扰,再加上海洋环境的高噪声背景、低的载波频率、极为有限的带宽以及传输条件的时间—空间—频率变化特性,使得通信过程十分困难。此外，水声通信试验的成本高，难度大，也为水声通信研究带来挑战。
本软件对水声信道的仿真研究很有帮助，可以产生声线图，冲激响应，声速图等仿真文件，结合Matlab画图工具绘制图像，对水声信道的模拟仿真很有帮助。-The most difficult problem faced by underwater acoustic communication is multi-path interference, which since multipath fading caused by the magnitude of the received signal, and mutual inter-symbol interference caused by multipath signal reception, plus the marine environment of high background noise, low carrier frequency , very limited bandwidth and transmission conditions of time- space- frequency characteristic such that the communication process is very difficult. In addition, the high cost of underwater acoustic communication experiment, difficult, and challenges for the study of underwater acoustic communication. This software is useful for simulation study of underwater acoustic channel can produce sound chart, impulse response, sound velocity diagrams simulation files, combined with Matlab drawing tools to draw the image of underwater acoustic channel simulation helpful. Platform: |
Size: 415744 |
Author:苏羽 |
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Description: Linear-Predictive-Coder
MATLAB Implementation of LPC algorithm for speech signal
# Why LPC?
In communication systems it is often necessary to transmit audio(speech) signal in compressed or encoded form because of bandwidth limitation of the channel. In this regard, ‘Linear predictive coding(LPC)’ is an effctive method of speech coding at a low bit-rate.
# Features
** Analysis/Encoding phase,Synthesis/Decoding phase.
**Human voice modelled with all-pole filter.
** LPC parameters(filter coefficients, pitch, gain etc) extraction at the decoding phase.
** Non-overlapping frames of 30 milliseconds in duration
# How To Run
** Make sure MATLAB(latest version) is installed
** Put both files(LPC.m with .mp3 file) in the same folder
** Open LPC.m file and run it.
## Comments
Different audio (.mp3) files can be coded/decoded by changing the input file name in the code. Platform: |
Size: 2048 |
Author:japaoli |
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Description: 1、验证窗函数 N 变化时，验证其频谱主瓣副瓣比、主瓣宽度的变化。
a)矩形窗函数的 N 变化时，验证其其频谱主瓣副瓣幅度比基本不会发生变化，
而主瓣宽度将会变窄。这说明，当用矩形窗函数设计滤波器时，增大 N 不能使
得阻带衰减减小，但能够减小过渡带。
b)再选取其他的窗如 hamming/hanning 窗，验证当 N 变化时，其频谱主瓣宽
度变化、主瓣副瓣比值变化情况。
2、用窗函数法设计线性相位 FIR 低通，通带截止频率 wp=0.5PI, 阻带截止频率 ws=0.6PI,
阻带衰减不小于 40dB,通带衰减不大于 3dB.
a)选取 Hanning,Hamming 窗查看设计出来的 FIR 的过渡带宽和阻带衰减是否
满足要求，二者有什么不同。
b)使用 hamming 窗，将窗长增大 1 倍，设计 FIR。验证同样的窗函数类型
(hamming)，不同窗长度时，设计出来的 FIR 的过渡带宽和阻带衰减都有什么变
化。
3、不使用 Matlab 系统函数得到上一项指标的低通，并与上一项结果比较。
4 用窗函数法设计线性相位 FIR 高通，通带截止频率 wp=0.8PI, 阻带截止频率
ws=0.7PI, 阻带衰减不小于 30dB,通带衰减不大于 3dB.(An actual filter is implemented using the truncated unit impulse response sequence of the ideal filter.
For the ideal low pass filter, the unit impulse response h, N, D () is intercepted by a length of N, and the length is
The N sequence H (n), when intercepted, guarantees causality and linear phase requirements for the filter.
In order to reduce the Gibbs effect, the H (n) window is added, and the appropriate window function is selected to ensure the stopband attenuation and
Transition zone requirement. Note that the sidelobe of the window function affects the stopband attenuation of the filter, and the main lobe width affects the filter
Transition bandwidth.) Platform: |
Size: 3072 |
Author:花祭嘉音
|
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Description: 产生一个高斯白噪声
利用MATLAB自带的fir1函数产生一个低通滤波器，限制高斯白噪声的带宽，由此产生了视频噪声。
利用产生的视频噪声，分别代入噪声调幅干扰的时域表达式，并且进行100次的积累后求平均值，对其进行快速傅里叶变换后，由此画出噪声调幅干扰的频域波形。
重复上述步骤，分别代入噪声调频干扰与噪声调相干扰的时域表达式，分别画出其频域波形与时域波形。(Generate a Gauss white noise
The fir1 function of MATLAB is used to generate a low-pass filter, which limits the bandwidth of Gauss white noise, and thus produces video noise.
Using the generated video noise, the time domain expressions of noise amplitude modulation interference are substituted, and the average value is calculated after 100 times accumulation. After fast Fourier transform, the frequency domain waveform of noise amplitude modulation interference is drawn.
Repeat the steps mentioned above, and substitute the time-domain expressions of noise FM interference and noise coherent interference, and draw the frequency-domain waveform and time-domain waveform respectively.) Platform: |
Size: 3072 |
Author:大丶哥 |
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Search - low bandwidth matlab