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Description: 8点基二fft
Fast Fourier Transform (FFT).
Using 8 points, takes about 1.2 ms to execute one FFT.
Sets up General Purpose Timer 1 to generate events at 10 kHz.
Will produce 10 kHz output on T1PWM and T1PWM pins. -8:00-two fft Fast Fourier Transform (FFT). Usi Vi eight points, takes about 120 ms to execute one FFT. Sets up Gen eral Purpose Timer 1 to generate events at 10 kHz . Will produce 10 kHz output on T1PWM and T1PWM pi ns.
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Size: 2391 |
Author: heben |
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Description: 说明：
pr[n]——输入的实部
pi[n]——数入的虚部
n，k——满足n=2^k
fr[n]——输出的实部
fi[n]——输出的虚部
l——0 FFT，1 IFFT
il——0 输出按实部/虚部；1 输出按模/幅角-: pr [n] -- imported real pi [n] -- the number-n, the imaginary part, k -- meet n = 2 ^ k fr [n] -- the real output fi [n] -- output of the imaginary part 1 -- 0 FF T, a IFFT il -- 0 output in real / imaginary parts; Die output by 1 / Angle
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Size: 1131 |
Author: 郑进 |
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Description: 已知一个序列x(n)=0.5cos(0.55*pi*n)+cos(0.45*pi*n),时域FFT分析其频谱。
（1）使用不同宽度的矩形窗截断该序列为M点，取M分别为：20，40，160,观察不同长度对频谱影响；（2）使用哈明窗和凯泽窗重做；（3）对三种窗的结果进行分析比较；（4）总结窗类型和长度对频谱分析的影响。
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Size: 971 |
Author: fg |
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Description: This function is written to understand and/or explain an fft algorithm and usage of radix2 procedure.
This function take the signal which you want to find FFT, for m bit
you can also call the function without entering a signal or number of points, because there is default values for y and m which are
y = sin(2*pi*50*t)+sin(2*pi*120*t)
m=3
you can see the steps of order reversing used as built-in function but non others. you will also see the taking butterfly tree steps.
for more information read the help file of function.
in future this can be improve as selective radix or any other feature you suggest please notice me for any sugestion.
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Size: 2904 |
Author: dairy |
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Description: 8点基二fft
Fast Fourier Transform (FFT).
Using 8 points, takes about 1.2 ms to execute one FFT.
Sets up General Purpose Timer 1 to generate events at 10 kHz.
Will produce 10 kHz output on T1PWM and T1PWM pins. -8:00-two fft Fast Fourier Transform (FFT). Usi Vi eight points, takes about 120 ms to execute one FFT. Sets up Gen eral Purpose Timer 1 to generate events at 10 kHz . Will produce 10 kHz output on T1PWM and T1PWM pi ns.
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Size: 2048 |
Author: heben |
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Description: 说明：
pr[n]——输入的实部
pi[n]——数入的虚部
n，k——满足n=2^k
fr[n]——输出的实部
fi[n]——输出的虚部
l——0 FFT，1 IFFT
il——0 输出按实部/虚部；1 输出按模/幅角-: pr [n]-- imported real pi [n]-- the number-n, the imaginary part, k-- meet n = 2 ^ k fr [n]-- the real output fi [n]-- output of the imaginary part 1-- 0 FF T, a IFFT il-- 0 output in real/imaginary parts; Die output by 1/Angle
Platform: |
Size: 1024 |
Author: 郑进 |
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Description: 已知一个序列x(n)=0.5cos(0.55*pi*n)+cos(0.45*pi*n),时域FFT分析其频谱。
（1）使用不同宽度的矩形窗截断该序列为M点，取M分别为：20，40，160,观察不同长度对频谱影响；（2）使用哈明窗和凯泽窗重做；（3）对三种窗的结果进行分析比较；（4）总结窗类型和长度对频谱分析的影响。
-Known a sequence x (n) = 0.5cos (0.55* pi* n)+ Cos (0.45* pi* n), time-domain FFT analysis of its spectrum. (1) use a different width of the rectangular window of the sequence for M cut-off point, take M are as follows: 20,40,160, observing the impact of different lengths of the spectrum (2) the use of Hamming window and the Kaiser window redo (3 ) on the three windows analyzed and compared the results (4) summarize the type and length of window for spectrum analysis.
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Size: 1024 |
Author: fg |
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Description: This function is written to understand and/or explain an fft algorithm and usage of radix2 procedure.
This function take the signal which you want to find FFT, for m bit
you can also call the function without entering a signal or number of points, because there is default values for y and m which are
y = sin(2*pi*50*t)+sin(2*pi*120*t)
m=3
you can see the steps of order reversing used as built-in function but non others. you will also see the taking butterfly tree steps.
for more information read the help file of function.
in future this can be improve as selective radix or any other feature you suggest please notice me for any sugestion.
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Size: 3072 |
Author: dairy |
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Description: // 入口参数：
// l: l = 0, 傅立叶变换 l = 1, 逆傅立叶变换
// il: il = 0,不计算傅立叶变换或逆变换模和幅角；il = 1,计算模和幅角
// n: 输入的点数，为偶数，一般为32，64，128，...,1024等
// k: 满足n=2^k(k>0),实质上k是n个采样数据可以分解为偶次幂和奇次幂的次数
// pr[]: l=0时，存放N点采样数据的实部
// l=1时, 存放傅立叶变换的N个实部
// pi[]: l=0时，存放N点采样数据的虚部
// l=1时, 存放傅立叶变换的N个虚部
//
// 出口参数：
// fr[]: l=0, 返回傅立叶变换的实部
// l=1, 返回逆傅立叶变换的实部
// fi[]: l=0, 返回傅立叶变换的虚部
// l=1, 返回逆傅立叶变换的虚部
// pr[]: il = 1,i = 0 时，返回傅立叶变换的模
// il = 1,i = 1 时，返回逆傅立叶变换的模
// pi[]: il = 1,i = 0 时，返回傅立叶变换的辐角
// il = 1,i = 1 时，返回逆傅立叶变换的辐角-err
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Size: 1024 |
Author: bluefeifei |
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Description: Linux 下 的superpi源码, 使用FFT算法实现可以做测试使用.-A good superpi source code running at linux/unix platform, also you can port to any hardware.Realized with FFT algorithm.
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Size: 143360 |
Author: Edwin |
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Description: OFDM程序，这么安排矩阵的目的是为了构造共轭对称矩阵
共轭对称矩阵的特点是 在ifft/fft的矢量上 N点的矢量
在0，N/2点必须是实数 一般选为0
1至N/2点 与 （N/2）+1至N-1点关于N/2共轭对称- BPSK simulation using a carrier cosine wave with ISI
clc
close all
clear all
figure(1)
n=160
for i=1:n
data(i)= 2*round(rand)-1
end
create modulated BPSK signal
first expand the bit stream
exdata=[]
for i=1:length(data)
for rep=1:5
exdata= [exdata data(i)]
end
end
ts=.1
t=1:ts:80.9
carrier=cos(pi*t)
multiply expanded bitstream by cosine wave with carrier frequency
this is the BPSK that is to be transmitted over the channel
bpsk=carrier.*exdata
bpsk=[bpsk(length(bpsk)-1) bpsk(length(bpsk)) bpsk]
plot(bpsk)
generating the noise
p=rand(1,800)*2*pi
p=rand*2*pi
snr=10
r=sqrt(-1*(1/snr*log(1- rand)))
no = 5*(r.* exp(j*p))
no = (r.* exp(j*p))
value of alpha
al=rand+j*rand
al=1
Spreading channel with the alpha as the variable
for k=5:5:795
for l = 1:5
al=round(rand)+j*round(rand)
rec(k+l)=bpsk(k+l)+al*bpsk(k-5+l)
end
end
rxdata=rec+ no
begin demodulation
first multiply recie
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Size: 6146048 |
Author: 卞敏捷 |
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Description: this fft header file for fast fourier transform. with this file, you can compute frequency spectrum zero to tow pi.-this is fft header file for fast fourier transform. with this file, you can compute frequency spectrum zero to tow pi.
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Size: 1024 |
Author: ha |
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Description: 一个简单的matlab程序。作用是用快速傅里叶变换（FFT），对心电信号去基线漂移。传统的去基线漂移方法没有提到FFt，只不过效果的确不太好。-Translate
From: Chinese
To: English
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一个简单的matlab程序。作用是用快速傅里叶变换（FFT），对心电信号去基线漂移。传统的去基线漂移方法没有提到FFt，只不过效果的确不太好。
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Yīgè jiǎndān de matlab chéngxù. Zuòyòng shì yòng kuàisù fu lǐ yè biànhuàn (FFT), duì xīn diàn xìnhào qù jīxiàn piāoyí. Chuántǒng de qù jīxiàn piāoyí fāngfǎ méiyǒu tí dào FFt, zhǐ bùguò xiàoguǒ díquè bù tài hǎo.EnglishSpanishArabicAlpha
A simple matlab program. The role of the fast Fourier transform (FFT), the ECG baseline drift. To baseline drift did not mention FFt, only the results have not been very good.
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Size: 90112 |
Author: 周雅琪 |
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Description: 快速傅立叶变换子程序
//l=0时，pr存放采样输入的实部，返回离散傅立叶变换的模；l=1时，pr存放傅立叶变换的实部，返回逆傅立叶变换的模
//l=0时，pi存放采样输入的虚部，返回离散傅立叶变换的幅角；l=1时，pi存放傅立叶变换的虚部，返回逆傅立叶变换的幅角
//l=0时，fr返回傅立叶变换的实部 l=1时返回逆傅立叶变换的实部
//l=0时，fi返回傅立叶变换的虚部 l=1时返回逆傅立叶变换的虚部 (l=0时正变换，l=1时逆变换)
//il=0时，表示不要求本函数计算傅立叶变换或逆傅立叶变换的模或幅角
//il=1时，表示要求本函数计算傅立叶变换或逆傅立叶变换的模或幅角-Fast Fourier Transform subroutine
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Size: 1024 |
Author: zhengru |
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Description: 去斜率（strech）参考信号与回波信号混频后得到中频输出信号S(t)=Aexp(j*2*pi*f0*t+phase)
其中f0与回波延时的关系为：
f0=k*delay_t
K为线性调频斜率，delay_t为回波延时
将s(t)采样，FFT变换即可得到目标距离与频谱的关系。
Strech 信号测距
输入混频后的中频信号（图一），经采样及FFT变换得到频谱（图二）
再根据频谱与距离的关系式R=Tcf/2B显示出距离(图三)
-Go slope (strech) obtained after the reference signal and the echo signal mixer IF output signal S (t) = Aexp (j* 2* pi* f0* t+phase) f0 and echo delay relationship: f0 = k* delay_t K chirp slope, delay_t the echo delay sampling s (t), the FFT transform to the target distance spectrum of relations. Strech signal ranging input mixer IF signal (Figure 1), sampling and FFT transform spectrum (Figure 2) according the the spectrum distance relationship R = Tcf/2B shows the distance (Figure 3)
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Size: 24576 |
Author: 江河 |
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Description: Matlab程序，GUI窗口
用FFT程序计算有限长度正弦信号y=sin(2*pi*f*t) ,0<=t<=N*T-FFT program calculate the finite length of the sinusoidal signal y = sin (2* pi* f* t), 0 < = t < = N* T respectively the DFT results obtained and analyzed and discussed in the following cases: a) the signal frequency f = 50Hz, the sampling the credited with N = 32, the sampling interval T = 0.000625sb) signal frequency f = 50Hz, the sampling points of N = 32, the sampling interval T = 0.005sc), the signal frequency f = 50 Hz, the sampling points N = 32, the sampling interval T = 0.0046875sd) signal frequency f = 50Hz, the sampling points of N = 32, the sampled interval T = 0.004se) signal frequency f = 50Hz, the sampling points of N = 64, the sampling interval the T = 0.000625sf) signal frequency f = 250Hz, the sampling points N = 32, the sampling interval T = 0.005sg) c) a signal-post 32, to do a 64-point FFT
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Size: 12288 |
Author: moumiao |
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Description: Matlab程序，GUI窗口用FFT程序计算有限长度正弦信号y=sin(2*pi*f*t) ,0<=t<=N*T
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Size: 12780 |
Author: 693766534@qq.com |
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Description: FFT使用范例。
x=0.5*sin(2*pi*15*t)+2*sin(2*pi*40*t)。采样频率fs=100Hz，分别绘制N=128、1024点幅频图。-FFT usage examples. x = 0.5* sin (2* pi* 15* t)+2* sin (2* pi* 40* t). Sampling frequency fs = 100Hz, were drawn N = 128,1024 point amplitude-frequency diagram.
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Size: 1024 |
Author: 王军 |
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Description: 信号y=sin(2*pi*f1*t)+sin(2*pi*f2*t)加上信噪比为2高斯白噪声的傅里叶变换，分别画出时域和频域图-Signal y = sin (2* pi* f1* t)+ sin (2* pi* f2* t) plus noise ratio for two Gaussian white noise of the Fourier transform, respectively, to draw the time domain and frequency domain
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Size: 1024 |
Author: 杜锋 |
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Description: 1.x=0.5*sin(2*pi*15*t)+2*sin(2*pi*40*t)。采样频率fs=100Hz，分别绘制N=128、1024点幅频图。
2.x=0.5*sin(2*pi*15*t)+2*sin(2*pi*40*t),fs=100Hz,绘制：
（1）数据个数N=32，FFT所用的采样点数NFFT=32；
（2）N=32，NFFT=128；
（3）N=136，NFFT=128；
（4）N=136，NFFT=512。-1. X = 0.5* sin (2* PI* 15* t)+ 2* sin (2* PI* 40* t).Sampling frequency fs = 100 hz, respectively to draw N = 128, 1024 point amplitude-frequency figure.
2. X = 0.5* sin (2* PI* 15* t)+ 2* sin (2* PI* 40* t), the fs = 100 hz, drawing:
(1) N = 32, NFFT = 32
(2) N = 32, NFFT = 128
(3) N = 136, NFFT = 128
(4) N = 136, NFFT = 512.
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Size: 1024 |
Author: Shawn |
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