基于Matlab模拟AWGN 信道上 OFDM.zip

%--------------------------------------------------------------------------------------------------- % In this example we show how OFDM system perform over AWGN channel. The % simulation results will be checked with ones we obtain through % theoritical analysis. % %--------------------------------------------------------------------------------------------------- % Initiliazation clear % clear all workspace variables clc % clear command window close all % close all open figures mFileName = mfilename; % Get mfile name mFileNameFull = mfilename('fullpath'); % Get mfile full name mFileDirMain = mFileNameFull(1:end-length(mFileName)); % Extract the dir of the mfile directory if ~isempty(mFileDirMain) cd(mFileDirMain) % change matlab current folder to mfile directory end clear mFileName mFileNameFull mFileDirMain % clear variables rng(0) % set the random seed to 0 if exist('OFDM_Class','class') == 8 % Check if OFDM_Class exits OFDM_Class.checkForUpdatedVersion(); % Check if the class is updated else fprintf('The OFDM_Class does not exist or its path is not added. You can download the class from this %s \n',... '<a href = "http://www.mathworks.com/matlabcentral/fileexchange/54070">Link</a>') return end %--------------------------------------------------------------------------------------------------- % Main Part %--------------------------------------------------------------------------------------------------- % Parameters % First curve Para1.NB = 5000; % Number of ofdm symbols per run Para1.I = 1; % Number of iterations in each loop Para1.M = 4; % Modulation order (4 QPSK) it can be changed by user Para1.N = 64; % Number of sybcarriers Para1.NFFT = 64; % Upsampling rate is 1, and FFT based interpolation is used Para1.ifDoRaylieghChannel = 0; % No Rayliegh channel Para1.ifDoAWGNChannel = 1; % Only AWGN Channel % Second curve Para2 = Para1; % all parameters are the same as what defined in Para1 except the modulation order Para2.M = 16; % Modulation order (16 QAM) it can be changed by user % Building class Obj1 = OFDM_Class(Para1); Obj2 = OFDM_Class(Para2); % Loop Parameters Loop.EbN0dB = 0:10; Loop.SNRdBVec1 = 10*log10(log2(Obj1.M))+Loop.EbN0dB; Loop.SNRdBVec2 = 10*log10(log2(Obj2.M))+Loop.EbN0dB; Loop.EbN0dBL = length(Loop.EbN0dB); Loop.Results = zeros(Loop.EbN0dBL,Obj1.I,8); Loop.Cnt = 0; % Main Loop fprintf('-------------------------------------\n') for LoopCnt1 = 1 : Loop.EbN0dBL % Update parameters Obj1.channSNRdB = Loop.SNRdBVec1(LoopCnt1); Obj2.channSNRdB = Loop.SNRdBVec2(LoopCnt1); for LoopCnt2 = 1 : Obj1.I % Transmitter Obj1.ofdmTransmitter(); Obj2.ofdmTransmitter(); % Channel Obj1.ofdmChannel(); Obj2.ofdmChannel(); % Receiver Obj1.ofdmReceiver(); Obj2.ofdmReceiver(); % BER calculation Obj1.ofdmBER(); Obj2.ofdmBER(); % Store the results for the first curve Loop.Results(LoopCnt1,LoopCnt2,1) = Obj1.BER; Loop.Results(LoopCnt1,LoopCnt2,2) = Obj1.DER; Loop.Results(LoopCnt1,LoopCnt2,3) = Obj1.BERTheoryAWGN; Loop.Results(LoopCnt1,LoopCnt2,4) = Obj1.EbN0dB; % Store the results for the second curve Loop.Results(LoopCnt1,LoopCnt2,5) = Obj2.BER; Loop.Results(LoopCnt1,LoopCnt2,6) = Obj2.DER; Loop.Results(LoopCnt1,LoopCnt2,7) = Obj2.BERTheoryAWGN; Loop.Results(LoopCnt1,LoopCnt2,8) = Obj2.EbN0dB; % Display Loop.Cnt = Loop.Cnt + 1; fprintf('%10.1f percent of the simulation is done.\n',Loop.Cnt*100/(Loop.EbN0dBL * Obj1.I)) end end fprintf('-------------------------------------\n') % Plots figure(1) clf semilogy(mean(Loop.Results(:,:,4),2), mean(Loop.Results(:,:,1),2),'bo:') % Simulation BER (first curve) hold on semilogy(mean(Loop.Results(:,:,4),2), mean(Loop.Results(:,:,3),2),'b-') % Theory BER (first curve) semilogy(mean(Loop.Results(:,:,8),2), mean(Loop.Results(:,:,5),2),'rs:') % Simulation BER (second curve) semilogy(mean(Loop.Results(:,:,8),2), mean(Loop.Results(:,:,7),2),'r-') % Theory BER (second curve) grid on xlabel('EbN0 [dB]') ylabel('BER') legend([Obj1.ModulationStr,'-Simulation'],[Obj1.ModulationStr,'-Theory'],... [Obj2.ModulationStr,'-Simulation'],[Obj2.ModulationStr,'-Theory']) title('OFDM system performance over AWGN channel')