%測試文件，一次性生成數個data symbol，按標準方法調制，組裝成待發送信號
%目的是快捷地調試解調模塊，尤其是sync的部分
%原先worked的一組數據s_1 s_2 s_3，原封不動地保存

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%                                    定義參數                                   %
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n_data=4;              %本程序產生的數據symbol個數
Tu=2048;               %for MODE I
delta=504;             %Guard interval
Ts=2552;               %toatal length of a symbol
k=1536;                %number of carriers

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%  信號發生器，生成的數放在mass_prj里，注意，這也是以用來和解調結果比較的源信號 %
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mass_prj=binornd(1,0.5,[n_data,k*2]); %參數為0.5的二項分布偽隨機數

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%                         QPSK mapping，結果放在QPSK_map里                      %
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%由于自然進化了行列操作，比原先的程序簡單許多，運行效率也更高
QPSK_map=(1/(2^0.5))*((1-(mass_prj(:,1:k)*2))+i*(1-(mass_prj(:,k+1:2*k)*2)));

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%                  Frequency interleaving,結果放在Freq_inter里                  %
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%matrix_k是頻率插值正變換矩陣，取自328目錄下的interleaver.m
Freq_inter=QPSK_map*matrix_k;

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%                       Differentiation,結果放在Diff_mo里                       %              
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%注意，此段程序以前并未編寫過
%用了累計積cumprod，使程序更簡單
Diff_mo=[];
for i_nk=1:k
    Diff_mo=[Diff_mo,cumprod(Freq_inter(:,i_nk))];
end
 
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%                       OFDM Modulation，結果放在OFDM_mo里                      %
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%OFDM調制器輸入端，1536個信號點，前768個和后768個互換位置
%再補上512個0，湊足2048個點，存為OFDM_in
OFDM_in=[Diff_mo(:,k/2+1:k),zeros(n_data,512),Diff_mo(:,1:k/2)];

%每行分別進行2048點的IFFT變換，結果仍是同維的復數矩陣
%當參數x是一個矩陣時，ifft(x)會對x的每一列分別進行ifft計算，而我需要的是每行分別
%進行ifft，因此采用了先轉置，再轉置回來的方法，注意 .'表示只轉置而不求共軛
OFDM_out=(ifft(OFDM_in.')).';

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%              給OFDM_mo里面的數加上guard interval，成為OFDM_guard              %
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OFDM_guard=[OFDM_out(:,1545:2048),OFDM_out];

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%                            創造一幀數據，放在frame_1里                        %
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frame_1=[null,PRS];
for i_frame_1=1:n_data
frame_1=[frame_1,OFDM_guard(i_frame_1,:)];
end

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%                           原始數據和待發送數據幀的存儲                        %
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save('imp data.mat','mass_prj','frame_1');