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matlab2015a
clc;clear;close all;warning off;addpath 'func\'addpath 'func\mfiles\'load data.matfs = 100e6;Nfft = 4096;fc = 5.8e9;% [x1,t1,ssf1,yy1] = plotspec(x,1/fs);% figure;% plot(ssf1,yy1) % plot magnitude spectrum% xlabel('frequency'); % ylabel('magnitude') % label the axes frameNumber = floor(length(x)/Nfft);txBlockFFT = zeros(frameNumber,Nfft);%对信号进行短时傅里叶变换，得到跳频图案for i = 0:frameNumber-1 start = i*Nfft; txBlockFFT(i+1,:) = fftshift(fft(x(start+1:start+Nfft))); %找出跳频图案中横轴上每个时间上对应的最大峰值，从时间开始到结束写个循环就行， [maxValue(i+1),maxIndex(i+1)] = max(abs(txBlockFFT(i+1,:)));end%计算峰值均值Level = 10*mean(maxValue);delta_f = fs/Nfft;f = delta_f: delta_f: fs;f = f - fs/2;%detect vaalid signalvalidIndexCount = 1;validIndex = zeros(1,1);validIndex(validIndexCount) = 0;validFrameCount = 0;figure;for i = 1:frameNumber-1 i %峰值搜索 if(max(abs(txBlockFFT(i+1,:))> Level)) validFrameCount = validFrameCount + 1; validFrame(validFrameCount) = i+1; if(abs(maxIndex(i+1) - validIndex(validIndexCount)) > 40) validIndexCount = validIndexCount +1; validIndex(validIndexCount) = maxIndex(i+1) ; detectFHFc = validIndex(2:end)*fs/Nfft- fs/2; end detectFHResult(i+1) = maxIndex(i+1)*fs/Nfft- fs/2+fc; t = (0:length(detectFHResult)-1)*Nfft/fs; plot(t,detectFHResult,'c*'); hold on end axis([0,0.1983,5.74e9,5.86e9]); pause(0.001);endhold on;y_label = fc*ones(1,length(detectFHResult));plot(t,y_label,'r');ylim([fc-50e6 fc+50e6]);xlabel('时间s')ylabel('频率Hz');grid on;FT = zeros(1000,length(t));%归一化频率indx=find(detectFHResult==0);detectFHResult1=detectFHResult;detectFHResult1(indx)=[];detectFHResult2 = detectFHResult-min(detectFHResult1);indx=find(detectFHResult2<0);detectFHResult2(indx)=0;detectFHResult3 = floor(1000*detectFHResult2/max(detectFHResult2));for i = 1:length(t) if detectFHResult3(i)>0 FT(detectFHResult3(i),i) = 1; endendSE = strel('disk',24);FT1 = imdilate(FT,SE);SE1 = strel('disk',4);FT1a = imerode(FT1,SE1);SE1 = strel('disk',8);FT2a = imerode(FT1,SE1);SE1 = strel('disk',12);FT3a = imerode(FT1,SE1); SE1 = strel('disk',16);FT4a = imerode(FT1,SE1); SE1 = strel('disk',20);FT5a = imerode(FT1,SE1); SE1 = strel('disk',23);FT6a = imerode(FT1,SE1); FTf = FT1a+FT2a+FT3a+FT4a+FT5a+FT6a;[X,Y]=meshgrid(t,0.001:0.001:1); %横坐标为1953~2006，纵坐标1~54 figure;contour(X,Y,FTf);xlabel('time/s');ylabel('归一化频率f/s');1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88.89.90.91.92.93.94.95.96.97.98.99.100.101.102.103.104.105.106.107.108.109.110.111.112.113.
clc;clear;close all;warning off;addpath 'func\'addpath 'func\mfiles\'load data.matfs = 100e6;Nfft = 4096;fc = 5.8e9;[x1,t1,ssf1,yy1,yy2]= plotspec(x,1/fs);figure;plot(ssf1(1:1:end)+fc,yy1(1:1:end)) % plot magnitude spectrumxlabel('frequency(Hz)'); ylabel('magnitude') % label the axesfs = 100e6;Nfft = 4096;frameNumber = floor(length(x)/Nfft);txBlockFFT = zeros(frameNumber,Nfft);for i = 0:frameNumber-1 i start = i*Nfft; txBlockFFT(i+1,:) = fftshift(fft(x(start+1:start+Nfft))); [maxValue maxIndex(i+1)] = max(abs(txBlockFFT(i+1,:)));endfc = 5.8e9;delta_f = fs/Nfft;f = delta_f: delta_f: fs;f = f - fs/2;%detect vaalid signalvalidIndexCount = 1;validIndex = zeros(1,1);validIndex(validIndexCount) = 0;validFrameCount = 0;for i = 1:frameNumber-1 i if(max(abs(txBlockFFT(i+1,:))> 280)) validFrameCount = validFrameCount + 1; validFrame(validFrameCount) = i+1; if(abs(maxIndex(i+1) - validIndex(validIndexCount)) > 40) validIndexCount = validIndexCount +1; validIndex(validIndexCount) = maxIndex(i+1) ; detectFHFc = validIndex(2:end)*fs/Nfft- fs/2; end detectFHResult(i+1) = maxIndex(i+1)*fs/Nfft- fs/2+fc; t = (0:length(detectFHResult)-1)*Nfft/fs; hold on endend ind1 = find(abs(detectFHResult)>0) ;ind2 = find(detectFHResult==0) ;detectFHResult(ind2)=[];flag = [];for i = 1:length(ind1)-1 if ind1(i+1)-ind1(i) > 20 flag = [flag,i]; endend%跳频周期for i = 1:length(flag) if i == 1 ind12(i) = ind1(flag(i)+1)-ind1(1); else ind12(i) = ind1(flag(i)+1)-ind1(flag(i-1)+1); endendcycle = floor(mean(ind12))+1;for i = 1:length(t)-cycle cyclss(i) = 1000*(t(cycle+i)-t(i));endmean(cyclss) 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.
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