function [output,count,pilot_sequence]=insert_pilot(pilot_inter,pilot_symbol_bit,map_out_block) 
% pilot_inter為導頻符號間隔，以ofdm符號個數的形式給出，為整數。間隔越大估計誤差越大
% pilot_symbol_bit 采用常數導頻符號，這里給出它的二進制形式
% map_out_block 映射后的一次仿真所包含的符號塊
  pilot_symbol=qam16(pilot_symbol_bit);     %導頻復符號
  [N,NL]=size(map_out_block);
  output=zeros(N,(NL+fix(NL/pilot_inter)));
  pilot_sequence=pilot_symbol*ones(N,1);
  
  count=0;%記錄插入導頻信號的次數
  i=1;
  while i<(NL+fix(NL/pilot_inter))%每隔pilot_inter個符號插入一個導頻序列
      output(:,i)=pilot_sequence;
      count=count+1;
   if count*pilot_inter<=NL
      output(:,(i+1):(i+pilot_inter))=map_out_block(:,((count-1)*pilot_inter+1):count*pilot_inter);
  else
      output(:,(i+1):(i+pilot_inter+NL-count*pilot_inter))=map_out_block(:,((count-1)*pilot_inter+1):NL);
  end
      i=i+pilot_inter+1;
  end