QPSK信號調製之ASCII碼

clear;close all;clc; sym_dec=(32:126).'; sym_bit=de2bi(sym_dec,8,'left-msb'); sym_bit=reshape(sym_bit.',1,[]); bits = repmat(sym_bit,1,50).'; % bit2 = reshape(bits,2,[]).'; N=length(bits)/2; M=4; pha_qpsk = qammod(bits,M,'InputType','bit','PlotConstellation',true); % 生成相位 Fs = 65536; % 採樣率 fc = 25120; % 載頻 RB = 4096; fd=Fs/RB; alpha = 0.25; h = rcosdesign(alpha,6,Fs/RB,'sqrt'); % 根升餘弦成形 len_x = length(pha_qpsk); xx = zeros(1,(len_x)*fd); for i = 1:len_x xx((i-1)*fd+1)=pha_qpsk(i); end bas_qpsk = conv(xx,h,'same'); % 成形濾波 Len = N*Fs/RB; t = 0:1/Fs:(Len-1)/Fs; sig_qpsk_pure = bas_qpsk.*exp(1j*2*pi*(fc)*t); % 混頻 sig_qpsk = 0.7*sig_qpsk_pure./max(abs(sig_qpsk_pure)); fid = fopen('QPSK_regu_32-126.mod','wb'); fwrite(fid,real(sig_qpsk),'single'); fclose(fid);