利用matlab对瑞利衰落信道仿真

使用matlab对瑞丽衰落信道进行仿真，信道建模

%16QAM-OFDM system;
clear all;
clear all;

N = 1024;                                                        %the total number of all subcarriers
Np = 128;                                                         %the number of pilot carriers
B = 2e6;                                                         %bandwidth 2MHz
T = 1/B;
Ng = 256;                                                        %the length of Guard Interval
Xp = 3 + 1.0*j ;                                                      %pilot value
t= 0;  % erro code number

for u = 1:20                                             % run 20 times
%-------------------------------------Data generator--------------------------------------------------
xr1 = rand（1N-Np）;
Xre = （-3） * （xr1 < 0.25） + （-1） * （0.25 <= xr1 & xr1 < 0.5）...
    + （0.5 <= xr1 & xr1 < 0.75） + 3 * （0.75 <= xr1 & xr1 < 1）;
xr2 = rand（1N-Np）;
Xim = （-3） * （xr2< 0.25） + （-1） * （0.25 <= xr2 & xr2 < 0.5）...
    + （0.5 <= xr2 & xr2 < 0.75） + 3 * （0.75 <= xr2 & xr2 < 1）;
X = complex（XreXim）;                                            %16QAM
% Xre = （-1） * （xr1 < 0.5） + 1 * （0.5 <= xr1 & xr1 < 1）;
% xr2 = rand（1N-Np）;
% Xim = （-1） * （xr2< 0.5） + 1 * （0.5 <= xr2 & xr2 < 1）;
% X = complex（XreXim）;                                            %QPSK
%----------------------------------  insert pilot in carriers    -------------------------------------
% pilots locate at 8*i + 3;
Xc = zeros（1N）;                                                 %the carrier value
m = 0;
for i = 1 : N
    if（mod（i8） == 3）
         Xc（i） = Xp;
         m = m + 1;
    else
        Xc（i） = X（i - m）;
    end
end
%----------------------------------OFDM modulation-------------------------------------------------------
Ym = ifft（XcN）;
%----------------------------------Insert GI  CP---------------------------------------------------------
Y = [Ym（769:N）Ym];
%----------------------------------pass channel-----------------------------------------------------------
Yc = ray_channel（YT）;
%---------------------------------add noice -------------------------------------------------------------
SNR = 40;
% for S=1:21
  %SNR= 10log10（Es/N0）
% N0 = var（Yc）/（10^（SNR/10））;
% sgma = sqrt（N0/2）;
% Yawgn=Yc+sgma*randn（1length（Yc））+sgma*randn（1length（Yc））*j;
Yawgn = awgn（YcSNR‘measured‘）;
%-------------------------------------------------------------------------------------------------------     
% ----------------------------------------------OFDM RECEIVER-------------------------------------------  
%----------------------------------------------OFDM demodulation----------------------------------------
Yr = fft（YawgnN）;
%-----------------------------------------------Pilot signal Extraction---------------------------------
c = 1;
for i = 3:8:N
    Yp（c） = Yr（i）;
    c = c + 1;
end
%----------------------------------- Pilot signal Estimation with LS Algorithm -------------------------   
Hp = Yp ./ Xp;

 属性            大小     日期    时间   名称
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     文件       4558  2005-09-12 18:55  朱志敏\OFDM_LS_directly.m

     文件        657  2005-09-12 18:52  朱志敏\ray_channell.m

     目录          0  2006-02-24 19:53  朱志敏

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