发布时间:2024-02-09 11:00
matlab2017b
1统计同步算法:
统计同步算法的基本思路,主要是通过多次采样测试,然后计算对应的概率分布,来确定其同步时刻。测试信号和频率点为:
最后得到的信号的眼图为:
其主要思路,其实就是对一段正弦信号进行多次采样,然后计算每次采样后得到的跟踪结论,然后计算对应的概率分布情况,最后根据其概率密度函数得到最后的时钟跟踪点。
clc;
clear;
close all;
warning off;
addpath 'func\'
%======================统计算法实现===========================
%测试次数
Sample_Time = 100;
for j = 1:Sample_Time
j
RandStream.setDefaultStream(RandStream('mt19937ar','seed',j));
%产生伪随机数
freqcarrier = 40e6+round(5000*randn(1,1));
freqSignal = 10e6;
freqSample = 640e6;
K = floor(freqSample/freqSignal);
numSample = 256;
periodSample = 1/freqSample;
sampleIndex = 0:numSample-1;
timeSequence = sampleIndex/freqSample;
Data1 = 2*(randn(1,numSample)>=0.5)-1;
Data1s = func_samples(Data1,K);
%模拟伪随机数,即随机数以周期性出现
msg2 = [Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s];
b = hanning(127);
msg = filter(b,1,msg2);
msg = msg/max(msg);
msg(1:1024) = [];
%调制
ff = cos(2*pi*freqcarrier.*[0:length(msg)-1]/freqSample);
signalSample = msg.*ff;
t = length(signalSample);
[f,sf] = T2Fv2(t,signalSample);
figure(1);
subplot(311);
plot(msg);
title('测试随机数');
axis([1,length(msg),-1.5,1.5]);
subplot(312);
plot(f,abs(sf));
xlabel('频率 Mhz');
subplot(313);
plot(sf);
xlabel('归一化频率 点数');
%==========================计算Fcourse========================
sf1(1) = 0;
index = find(sf== max(sf));
I = 3;
Fcourse = index;
tic;
Fth = Fcourse;
N = length(signalSample);
Ntemp = N*(Fcourse-0.5)/Fth;
numTemp = round(Ntemp);
[ftemp,sftemp]= T2Fv2(t,signalSample(1:N));
sftemp(1) = 0;
indexTemp = find(sftemp== max(sftemp));
if sftemp(indexTemp) > sftemp(indexTemp-1)
Fth = Fth+0.1;
else
Fth = Fth-0.1;
end
Fpresize2(j)=Fth;
t(j) = toc;
end
figure;
hist(Fpresize2,10);
%计算概率分布
[m,n] = hist(Fpresize2,100);
[V,I] = max(m);
Fpresize = Fpresize2(I);
fprintf('%12.8f',Fpresize);
figure;
%恢复眼图
delta = (16320)/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(211)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('标准眼图');
grid on;
%恢复眼图
delta = Fpresize/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(212)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('同步之后眼图');
grid on;
p=100*abs(Fpresize-16320)/16320;
fprintf('估计精度:');
fprintf('%2.4f',p);
fprintf('%%\n');
t2 = mean(t);
fprintf('仿真时间:');
fprintf('%2.4f',t2);
fprintf('s\n');
save r4.mat t2 p
BTDT:
这个部分的仿真结果如下所示:
BTDT的基本步骤如下所示:
软同步方案中,为了重建眼图,需要确定采样步长Δt,Δt是通过Δt = FT/N,来确定的,T为信号周期的步长,N是采样点的数目,F是采样数据的包络。通过对这些采样的数据进行傅立叶变换,我们可以利用数值的方法确定包络的数目F’,可是离散傅立叶变换的谱分辨率有限,实际的F在F’- 0.5 to F’+0.5之间。为重建眼图,我们必须得到精确的F值。
实际的F值可以采用我们最近提出的二进制数据截断法BTDT,迅速而有效地得到。其工作原理如下:首先采样得到的数据的长度被截断为Nth = N/2F,因而数据的的数目减为N’ =N-Nth。接着对截断的数据进行傅立叶变换来计算其功率谱,并比较P(F’) 和 P(F’-1),P(f)为频率f的谱功率。如果P(F’-1) > P(F’),实际的F值应该位于小于F’的范围内。
相反,如果P(F’-1) < P(F’),如果F值应该高于F’。以相同的方式,我们重复截短数据Nth =N*[Fth-(F’-0.5)]/Fth 倍,Fth为预测的F范围的中心频率。经过m次迭代计算,F的准确度提高了2m倍。采用BTDT方法,采用标准的台式机,眼图重建可以在<0.3s的时间内完成,因此使每次扫描的实时再同步成为可能。
clc;
clear;
close all;
warning off;
addpath 'func\'
RandStream.setDefaultStream(RandStream('mt19937ar','seed',1));
%产生伪随机数
freqcarrier = 40e6;
freqSignal = 10e6;
freqSample = 640e6;
K = freqSample/freqSignal;
numSample = 256;
periodSample = 1/freqSample;
sampleIndex = 0:numSample-1;
timeSequence = sampleIndex/freqSample;
Data1 = 2*(randn(1,numSample)>=0.5)-1;
Data1s = func_samples(Data1,K);
%模拟伪随机数,即随机数以周期性出现
msg2 = [Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s];
b = hanning(127);
msg = filter(b,1,msg2);
msg = msg/max(msg);
msg(1:1024) = [];
%调制
ff = cos(2*pi*freqcarrier.*[0:length(msg)-1]/freqSample);
signalSample = msg.*ff;
t = length(signalSample);
[f,sf] = T2Fv2(t,signalSample);
figure;
subplot(311);
plot(msg);
title('测试随机数');
axis([1,length(msg),-1.5,1.5]);
subplot(312);
plot(f,abs(sf));
xlabel('频率 Mhz');
subplot(313);
plot(sf);
xlabel('归一化频率 点数');
%==========================计算Fcourse========================
sf1(1) = 0;
index = find(sf== max(sf));
I = 3;
Fcourse = index;
tic;
%==========================利用BTDT计算Fpresize================
Fth = Fcourse;
N = length(msg);
for k = 1:I
Ntemp = N*(Fcourse-0.5)/Fth;
numTemp = round(Ntemp);
[ftemp,sftemp]=T2Fv2(t,signalSample(1:numTemp));
sftemp(1) = 0;
indexTemp = find(sftemp== max(sftemp));
if sftemp(indexTemp)>sftemp(indexTemp-1)
Fth = Fth+(0.5)^(k+1);
else
Fth = Fth-(0.5)^(k+1);
end
end
format long;
Fpresize = Fth;
fprintf('%6.5f\n',Fpresize);
clc;
t=toc;
figure;
%恢复眼图
delta = (Fcourse)/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(211)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('标准眼图');
grid on;
%恢复眼图
delta = Fpresize/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(212)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('同步之后眼图');
grid on;
p=100*abs(Fpresize-Fcourse)/Fcourse;
fprintf('估计精度:');
fprintf('%2.4f',p);
fprintf('%%\n');
fprintf('仿真时间:');
fprintf('%2.4f',t);
fprintf('s\n');
save r2.mat t p
CZT:
这个部分的仿真结果如下所示:
CZT的基本步骤如下所示:
http://d.wanfangdata.com.cn/Periodical_zjbgcxyxb201201013.aspx
clc;
clear;
close all;
warning off;
addpath 'func\'
RandStream.setDefaultStream(RandStream('mt19937ar','seed',1));
%产生伪随机数
freqcarrier = 40e6;
freqSignal = 10e6;
freqSample = 640e6;
K = freqSample/freqSignal;
numSample = 256;
periodSample = 1/freqSample;
sampleIndex = 0:numSample-1;
timeSequence = sampleIndex/freqSample;
Data1 = 2*(randn(1,numSample)>=0.5)-1;
Data1s = func_samples(Data1,K);
%模拟伪随机数,即随机数以周期性出现
msg2 = [Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s];
b = hanning(127);
msg = filter(b,1,msg2);
msg = msg/max(msg);
msg(1:1024) = [];
%调制
ff = cos(2*pi*freqcarrier.*[0:length(msg)-1]/freqSample);
signalSample = msg.*ff;
t = length(signalSample);
[f,sf] = T2Fv2(t,signalSample);
figure;
subplot(311);
plot(msg);
title('测试随机数');
axis([1,length(msg),-1.5,1.5]);
subplot(312);
plot(f,abs(sf));
xlabel('频率 Mhz');
subplot(313);
plot(sf);
xlabel('归一化频率 点数');
%==========================计算Fcourse========================
sf1(1) = 0;
index = find(sf== max(sf));
I = 3;
Fcourse = index;
tic;
%==========================CZT实现===========================
F1 = 2e7;%细化频率段起点
F2 = 6e7;%细化频率段终点
M = 2^16;%细化频段的频点数,(这里其实就是细化精度)
w = exp(-j*2*pi*(F2-F1)/(freqSample*M));%细化频段的跨度(步长)
a = exp(j*2*pi*F1/freqSample);%细化频段的起始点,这里需要运算一下才能代入czt函数
xk = czt(signalSample,M,w,a);
h = 0:1:M-1;%细化频点序列
deltaFreq = freqSample/length(signalSample);
index1 = F1/deltaFreq;
index2 = F2/deltaFreq;
f0 =(F2-F1)/M*h+F1;%细化的频率值
f00 =(index2-index1)/M*h+index1;%细化的频率值
Fpresize = f00(find(xk==max(xk))-1);%%%%不对
fprintf('%6.5f',Fpresize);
t=toc;
figure;
%恢复眼图
delta = (Fcourse)/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(211)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('标准眼图');
grid on;
%恢复眼图
delta = Fpresize/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(212)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('同步之后眼图');
grid on;
p=100*abs(Fpresize-Fcourse)/Fcourse;
fprintf('估计精度:');
fprintf('%2.4f',p);
fprintf('%%\n');
fprintf('仿真时间:');
fprintf('%2.4f',t);
fprintf('s\n');
save r3.mat t p
ZOOM_FFT
这个部分的仿真结果如下所示:
clc;
clear;
close all;
warning off;
addpath 'func\'
RandStream.setDefaultStream(RandStream('mt19937ar','seed',1));
%产生伪随机数
freqcarrier = 40e6;
freqSignal = 10e6;
freqSample = 640e6;
K = freqSample/freqSignal;
numSample = 256;
periodSample = 1/freqSample;
sampleIndex = 0:numSample-1;
timeSequence = sampleIndex/freqSample;
Data1 = 2*(randn(1,numSample)>=0.5)-1;
Data1s = func_samples(Data1,K);
%模拟伪随机数,即随机数以周期性出现
msg2 = [Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s,Data1s];
b = hanning(127);
msg = filter(b,1,msg2);
msg = msg/max(msg);
msg(1:1024) = [];
%调制
ff = cos(2*pi*freqcarrier.*[0:length(msg)-1]/freqSample);
signalSample = msg.*ff;
t = length(signalSample);
[f,sf] = T2Fv2(t,signalSample);
figure;
subplot(311);
plot(msg);
title('测试随机数');
axis([1,length(msg),-1.5,1.5]);
subplot(312);
plot(f,abs(sf));
xlabel('频率 Mhz');
subplot(313);
plot(sf);
xlabel('归一化频率 点数');
%==========================计算Fcourse========================
sf1(1) = 0;
index = find(sf== max(sf));
I = 3;
Fcourse = index;
tic;
%==========================ZOOMFFT===========================
F1 = 2e7;%细化频率段起点
F2 = 6e7;%细化频率段终点
M = 2^16;%细化频段的频点数,(这里其实就是细化精度)
fi = 1e8; %最小细化截止频率
np = 32; %放大倍数
nfft = M;
clc;
xk = zfft_m(signalSample,fi,freqSample,nfft,np);
t=toc;
h = 0:1:M-1;%细化频点序列
deltaFreq = freqSample/length(signalSample);
index1 = F1/deltaFreq;
index2 = F2/deltaFreq;
f0 = (F2-F1)/M*h+F1;%细化的频率值
f00 = (index2-index1)/M*h+index1;%细化的频率值
Fpresize = f00(find(xk==max(xk))+1);
fprintf('%6.5f',Fpresize);
figure;
%恢复眼图
delta = (Fcourse)/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(211)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('标准眼图');
grid on;
%恢复眼图
delta = Fpresize/length(msg);
Xpoint = mod((1:length(msg))*delta,64);
Ypoint = msg;
subplot(212)
tip = ceil((1:length(msg))*delta);
for k = 1:max(tip)
indexSS = find(tip==k);
plot(Xpoint(indexSS),Ypoint(indexSS));
hold on;
end
axis([2.3,18.4,-0.96,0.96]);
title('同步之后眼图');
grid on;
p=100*abs(Fpresize-Fcourse)/Fcourse;
fprintf('估计精度:');
fprintf('%2.4f',p);
fprintf('%%\n');
fprintf('仿真时间:');
fprintf('%2.4f',t);
fprintf('s\n');
save r4.mat t p
A15-03