ofdm.m

简单的OFDM系统仿真

function[TotEbNo,Errors]=OFDM(Mt,Mr);

load ENC2.mat
load ENC4.mat
load ENC16.mat
load ENC64.mat
load ENC256.mat

A=[1 1/exp(1) 1/exp(2)];
N=64;
GI=16;
sig2=1e-3;
M=8;
Mgap=10.^(1:(1.7/10):2.7);
Btot=100*Mt;
TransmitIter=50;
ChannelIter=100;
GapIter=length(Mgap);

TotEbNo=[];
Errors=[];
EbNo=[];
for 1Gap=1:GapIter
    gap=Mgap(1Gap);
    totalErrors=0;
    for 1Chan=1:ChannelIter
        [H h_f]=create_channel(Mt,Mr,A,N+GI);
        [USV]=svd_decompose_channel(Mt,Mr,h_f,N);
        [bits_alloc,energy_alloc]=BitLoad(S,Btot,Mt*N,gap,sig2,M);
        for 1Trans=1:TransmitIter
            x=(randn(1,Btot)>0);
            x_mod=modu(x,bits_alloc,energy_alloc,s2,s4,s16,s64,s256);
            x_pre=precode(Mt,x_mod,V,N);
            
            ofdm_symbol=[];
            for i=1:Mt
                ofdm_symbol=[ofdm_symbol;ifft_cp_tx_blk(x_pre(i:Mt:Mt*(N-1)+i),N,GI)];
            end
            ofdm_symbol2=reshape(ofdm_symbol,Mt*(N+GI),1);
            
            y=transpose(channel(sig2,Mt,Mr,ofdm_symbol2,H,N+GI));
            
            rec_symbol=[];
            for i=1:Mt;
                rec_symbol=[rec_symbol;fft_cp_rx_blk(y(i:Mt:Mt*(N+GI-1)+i),N,GI)];
            end
            rec_symbol2=reshape(rec_symbol,1,Mt*N);
            
            shaped_vals=shape(rec_symbol2,Mr,U,N);
            
            y_demod=demodulate(shaped_vals,bits_alloc,energy_alloc,S,s2,s4,s16,s64,s256,c2,c4,c16,c64,c256);
            
            totalErrors=totalErrors+sum(xor(y_demod,x));
        end
        EbNo=[EbNo sum(energy_alloc)/Btot/sig2];
    end
    Errors=[Errors totalErrors/Btot/ChannelIter/TransmitIter];
    TotEbNo=[TotEbNo mean(EbNo)];
    EbNo=[];
end