dft_estimation.m

本代码是基于OFDM系统的一种转换域估计算法

function [ output,LL ] = DFT_estimation( input,pilot_inter,pilot_sequence,pilot_num )
%TRANSFORM_DOMAIN_ESTIMATION Summary of this function goes here
%   Detailed explanation goes here
[N,NL]=size(input);
output=zeros(N,NL-pilot_num);
 i=1;
 count=0;
  while i<=NL
      Hi=input(:,i)./pilot_sequence;
      a=zeros(128,1);
      for ii=1:128
          a(ii)=abs(Hi(ii));
      end
      % Hdft
      Hi_ifft=ifft(Hi);
      padding_zero=zeros(112,1);
      LL=16; % LL具体是多少可通过进一步的方法来确定以达到理想mse
      Hi_ifft_padding_zero=[Hi_ifft(1:LL);padding_zero];
      Hdft=fft(Hi_ifft_padding_zero);      
      % Hdft
      count=count+1;
      if  count*pilot_inter<=(NL-pilot_num)
          for p=((count-1)*pilot_inter+1):count*pilot_inter 
            output(:,p)=input(:,(i+p-(count-1)*pilot_inter))./Hdft; 
          end
      else
          for p=((count-1)*pilot_inter+1):(NL-pilot_num)
            output(:,p)=input(:,(i+p-(count-1)*pilot_inter))./Hdft;
          end
      end
      i=i+pilot_inter+1;
  end