多相滤波器及信道化处理_多相滤波器 信道化

目录

一 降采样和多相滤波器

二 升采样和多相滤波器

三 多相滤波器和信道化处理1

四 多相滤波器和信道化处理2

一 降采样和多相滤波器

二 升采样和多相滤波器

三 多相滤波器和信道化处理1

上图中从x(mD-p)可以看出,输入数据是从K到0，所以下面的代码里面是先x(K)到x(0),hp是从小到大顺序取值。

中，值是从0:1:length(h)长度，其中奇数时为0，相当于在原值基础上进行了插值，这也是重叠50%的由来。

四 多相滤波器和信道化处理2

上图重叠没有画清楚，如下图所示：

 当K=D时的代码：

 
clear 
close all
freqStart = 0;%app.MhzEditField.Value*1e6;
freqEnd = 0;%app.MhzEditField_2.Value*1e6;
fs     = 1600;%;app.MhzEditField_3.Value;        
%构造发送数据，实际设备中不存在
signalType = 'pulse';
bandwidth = 50;
A = 1;
Fc =100;%freqStart;%将信号放在freqStart和freqEnd之间，暂时放在freqStart位置
fsRev = 1600;%暂时按照3Ghz的采样率
 
%半带滤波
t = [0:1/fs:1];
receiveData = exp(1i*2*pi*Fc*t);   
% %% 参数设置
K = 8;
D =8  ;
fc = [0:K-1]*fs/K ;
load('passBand80Fc100Fs1600.mat')
h=passBand80Fc100Fs1600;
% hSub = (reshape(h,K,length(h)/K));
% 
% % =======传统方式
len = length(receiveData);
lenH = length(h);
lensubdata = len/K;
FFTNum = 8192;
for i = 1:K
     subplot(K,1,i)
     receiveDatatemp = receiveData.*exp(-1i*2*pi*fc(i)*(0:len-1)/fs);
     subchannelData = downsample(conv(receiveDatatemp,h,'same'),D);
     fftData = fft(subchannelData,FFTNum);
 
 
     plot([-FFTNum/2:FFTNum/2-1]*fs/D/FFTNum+fc(i),abs([fftData(FFTNum-FFTNum/2+1:FFTNum)  fftData(1:FFTNum/2)]));
    
end
 
 
receiveDataArray = [receiveData];
datalen = floor(length(receiveDataArray)/D)-2;
Hlen =  floor(length(h)/D)-2;
load('passBand80Fc100Fs1600.mat')
h=passBand80Fc100Fs1600;
 
hSub = (reshape(h,K,length(h)/K));
% % 多相滤波器信道分段为K,抽样为D=K/2
for i=1:K
    datatemp  = receiveDataArray(K-i+1:D:K-i+datalen*D);  %注意取数据的方式为倒序
    hupsample = hSub(i,:);%(upsample(hSub(i,:),2));
%     sig =(-1).^((i-1)*[0:length(datatemp)-1]);% 
    receiveDataArray2(i,:)= conv(datatemp,hupsample,'same');
end
receiveDataArray3 = ifft(receiveDataArray2);
 
FFTNum = 8192;
figure
fftwhole = [];
 
%频谱拼接
for i = 1:K
    subplot(K,1,i)
    fftData = (fft(receiveDataArray3(i,:),FFTNum));
   
 
    plot([-FFTNum/2:FFTNum/2-1]*fs/D/FFTNum+fc(i),abs([fftData(FFTNum-FFTNum/2+1:FFTNum)  fftData(1:FFTNum/2)]));
    
end
aa=1;
 
 
 
 

当K=2D时的代码

 
%宽带分段采集，频谱拼接 电平调节
% function IFSignalReceive(app)
clear 
close all
freqStart = 0;%app.MhzEditField.Value*1e6;
freqEnd = 0;%app.MhzEditField_2.Value*1e6;
fs     = 1600;%;app.MhzEditField_3.Value;
          
Fc =1200;%freqStart;%将信号放在freqStart和freqEnd之间，暂时放在freqStart位置
t = [0:1/fs:1];
receiveData = exp(1i*2*pi*Fc*t);   
% %% 参数设置
K = 8;
D =4  ;
fc = [0:K-1]*fs/K ;
load('passBand80Fc200Fs1600.mat')
h=passBand80Fc200Fs1600;
% hSub = (reshape(h,K,length(h)/K));
% 
% % =======传统方式
len = length(receiveData);
lenH = length(h);
lensubdata = len/K;
FFTNum = 8192;
for i = 1:K
     subplot(K,1,i)
     receiveDatatemp = receiveData.*exp(-1i*2*pi*fc(i)*(0:len-1)/fs);
     subchannelData = downsample(conv(receiveDatatemp,h,'same'),D);
     fftData = fft(subchannelData,FFTNum);    
     plot([-FFTNum/4:FFTNum/4-1]*fs/D/FFTNum+fc(i),abs([fftData(FFTNum-FFTNum/4+1:FFTNum)  fftData(1:FFTNum/4)]))     
end
 
 
receiveDataArray = [receiveData];
datalen = floor(length(receiveDataArray)/D)-2;
Hlen =  floor(length(h)/D)-2;
% load('passBand100Fc150Fs1600.mat')
load('passBand80Fc200Fs1600.mat')
 
h=passBand80Fc200Fs1600;
 
hSub = (reshape(h,K,length(h)/K));
% % 多相滤波器信道分段为K,抽样为D=K/2
for i=1:K
    datatemp   = receiveDataArray(K-i+1:D:K-i+datalen*D);  %注意取数据的方式为倒序
    hupsample = upsample(hSub(i,:),2);
    datatemp = datatemp;
    receiveDataArray2(i,:)=conv(datatemp,hupsample,'same');
end
receiveDataArray3 = ifft(receiveDataArray2,[],1);
 
FFTNum = 8192;
figure
fftwhole = [];
 
%频谱拼接
for i = 1:K
    subplot(K,1,i)
    datatemp =  (-1).^((i-1)*[0:length(datatemp)-1]);
    datatemp = receiveDataArray3(i,:).*datatemp;
    fftData = K*(fft(datatemp,FFTNum));  
    plot([-FFTNum/4:FFTNum/4-1]*fs/D/FFTNum+fc(i),abs([fftData(FFTNum-FFTNum/4+1:FFTNum)  fftData(1:FFTNum/4)]));
     
    
end
 
 
 
 
 

滤波器设置如下图：

从上面仿真可以看出，当K=D时，如果Fc为100hz时，由于频谱有盲区导致显示不到频谱，而当K=2*D时则可以显示正确的频谱