clear all
clc
hold on

%Parameter setting
fftn = 128;  %FFT點(diǎn)數(shù)
CP_length = fftn/8; %循環(huán)前綴長(zhǎng)度
symbol_num = 1e2; %OFDM符號(hào)數(shù)
M = 1;      %調(diào)制階數(shù)（1——BPSK）?????????
data_length = fftn*symbol_num*M;  %數(shù)據(jù)長(zhǎng)度

%Data generating
data_source = bingen(data_length);

%OFDM modulate
data4ifft = reshape(data_source,fftn,symbol_num);  %S/P

ifft_out = sqrt(fftn)*ifft(data4ifft);   %ifft  為什么求iff的sqrt???
ifft_out_temp1 = ifft_out;
%=================================================
%壓縮擴(kuò)展變換
%=================================================
         u = 3; %變換因子
         A = max(max(abs(ifft_out)));
         for ii = 1:symbol_num
             xn = ifft_out(:,ii);
             av_p = xn'*xn/fftn;
             for kk = 1:fftn
                 temp = ifft_out(kk,ii);
                 ifft_out(kk,ii) = A*temp*log(1+u*abs(temp)/A)/(log(1+u)*abs(temp));
             end
             av_p1 = ifft_out(:,ii)'*ifft_out(:,ii)/fftn;
             ifft_out(:,ii) = av_p*ifft_out(:,ii)/av_p1;
         end
         
         %CCDF計(jì)算
         plotPAPR = zeros(1,symbol_num);
         for ii = 1:symbol_num
             xn1 = ifft_out(:,ii);
             arverage_pwr = xn1'*xn1/fftn;%(平均功率是這樣計(jì)算的：求每一個(gè)樣值的功率在求和然后求平均)
             max_value = max(abs(xn1));
             PAPR = max_value^2/arverage_pwr;%計(jì)算發(fā)送信號(hào)的PAPR及平均功率
             plotPAPR(ii) = 10*log10(PAPR);
         end
         
         CCDF = zeros(1,131);
         for jj = 1:.1:13
             j = j+1;
             PAR_temp = zeros(1,symbol_num);
             PAR_temp(find(plotPAPR > jj-1)) = 1;%??????????
             CCDF(jj) = sum(PAR_temp)/symbol_num;
         end
         PAR_max = 0:12;%(門(mén)限值)
         semilogy(PAR_max,CCDF,'g+-')
         grid on