function[TotEbNo,Errors]= OFDM(Mt,Mr);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%function[TotEbNo,Errors]= OFDM(Mt,Mr);
%
%輸入：
%   Mt   ----發送天線數
%   Mr   ----接收天線數
%輸出:
%   TotEbNo ----信躁比 
%   Errors ----平均誤比特率 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


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 lGap = 1:GapIter
    gap = Mgap(lGap);
    totalErrors = 0;
    for lChan = 1:ChannelIter
        %創建信道 
        [H h_f] =create_channel(Mt,Mr,A,N+GI);
        %在頻域中分解每個子信道
        [U S V] = svd_decompose_channel(Mt,Mr,h_f,N);
        %比特分配 
        [bits_alloc,energy_alloc] = BitLoad(S,Btot,Mt*N,gap,sig2,M);
        %能量分配 
        for lTrans = 1:TransmitIter
            %傳輸的比特
            x = (randn(1,Btot)>0);
            %調制 
            x_mod = modu(x,bits_alloc,energy_alloc,s2,s4,s16,s64,s256);
            %調制信號預編碼 
            x_pre =precode(Mt,x_mod,V,N);
            %ifft，含循環前綴 
            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);
            %信道 
            y = transpose(channel(sig2,Mt,Mr,ofdm_symbol2,H,N+GI));
            %fft
            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);
            %接收信號成形
            shaped_vals = shape(rec_symbol2,Mr,U,N);
            %解調 
            y_demod = demodulate(shaped_vals,bits_alloc,energy_alloc,S,s2,s4,s16,s64,s256,c2,c4,c16,c64,c256);
            %比較
            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