% Experiment 5, CSBOOK: Haykin% Timing (clock) recovery% Measured S-curve of the % NDA-ELD loop, No-noiseclear all% time slotT=1/8000;deltaT=T/50;%Nyquest pulset=[-3*T/2+deltaT/2:deltaT:3*T/2-deltaT/2];h=sinc(2*t./T).*(cos(pi*t./T)./(1-2*t./T).^2);% Generating QPSK signalsno_of_bits=2000;b=round(rand(no_of_bits,1));bits=2*b-1;bitsi=bits(1:2:length(bits)-1);bitsq=bits(2:2:length(bits));amp=(bitsi+i*bitsq)/sqrt(2);amp=conj(amp');%FIR filterings_i=upfirdn(real(amp),h,50,1);s_q=upfirdn(imag(amp),h,50,1);s=s_i+i*s_q;x=s(1: length(s)-15);% FIR filteringy_i=upfirdn(real(x),h,50,1);y_q=upfirdn(imag(x),h,50,1);y=(y_i+y_q);%Timong error predictiontau=15;tauerror=-50:50;tauhat=tau-tauerror;for k=1:990     tp(k,:)=y(75+50*k+48+tauhat)-y(75+50*k+3+tauhat);     tq(k,:)=y(75+50*k+25+tauhat);     tqconj(k,:)=conj(tq(k,:));     e(k,:)=real(tqconj(k,:).*tp(k,:));end%Accumulate S_curvefor k=1:length(tauerror)  S_curve(k)=mean(e(:,k));end% plotsplot(-0.48:1/50:0.5, S_curve(51:100))ylabel('S-curve')xlabel('Normalized timing offset, \delta/T')