Some one help me in this.

%Script for parts a & b
%Part a
t1=-0.08;
t2=0.16;
ntp=1200;
us=3;
t=t1:(t2-t1)/ntp:t2;
x=80*sinc(100*t)+25*sinc(100*t-1)+90*sinc(20*t-0.8)+25*sinc(50*t-3)+80*sinc(100*t-8);
f=-100:0.1:100;
X=0.8*(1+exp(-j*0.16*pi*f)).*(us(f+50)-us(f-50))+0.5*(exp(-j*0.04*pi*f))+exp(-j*0.12*pi*f).*(us(f+25)-us(f-25))+4.5*(exp(-j*0.08*pi*f)).*(us(f+10)-us(f-10));

Array indices must be positive integers or logical values.

plotting statements
%Part b
for i=1:3
figure;
if(i==1)
T=1/75;
elseif(i==2)
T=1/100;
else
T=1/125;
end
    N1=floor(t1/T)-20;
    N2=ceil(t2/T)+20;
    n=N1:N2;
    nT=N1*T:T:N2*T;
    xnT=80*sinc(100*nT)+25*sinc(100*nT-1)+90*sinc(20*nT-0.8)+25*sinc(50*nT-3)+80*sinc(100*nT-8);
    tm=meshgrid(t,1:size(n,2));
    nTm=meshgrid(nT,1:size(t,2))';
    xnTm=meshgrid(xnT,1:size(n,2))';
    xr=sum(100*T*xnTm.*sinc(100*(tm-nTm)));
    plotting statements
end;

Answer 1

[Star Strider]

Since ‘us’ is a scalar, any index other than 1 will throw an error.

Since the desired result is likely multiplication, and MATLAB does not recognise implicit multiplication, put the appropriate operators

X=0.8*(1+exp(-j*0.16*pi*f)).*(us(f+50)-us(f-50))+0.5*(exp(-j*0.04*pi*f))+exp(-j*0.12*pi*f).*(us(f+25)-us(f-25))+4.5*(exp(-j*0.08*pi*f)).*(us(f+10)-us(f-10));

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I believe that’s all of them.

However there are still array size problems in this assignment —

xr=sum(100*T*xnTm.*sinc(100*(tm-nTm)));

so I will leave that to you to sort.

%Script for parts a & b
%Part a
t1=-0.08;
t2=0.16;
ntp=1200;
us=3;
t=t1:(t2-t1)/ntp:t2;
x=80*sinc(100*t)+25*sinc(100*t-1)+90*sinc(20*t-0.8)+25*sinc(50*t-3)+80*sinc(100*t-8);
f=-100:0.1:100;
X=0.8*(1+exp(-j*0.16*pi*f)).*(us*(f+50)-us*(f-50))+0.5*(exp(-j*0.04*pi*f))+exp(-j*0.12*pi*f).*(us*(f+25)-us*(f-25))+4.5*(exp(-j*0.08*pi*f)).*(us*(f+10)-us*(f-10));
% plotting statements
%Part b
for i=1:3
    figure;
    if(i==1)
        T=1/75;
    elseif(i==2)
        T=1/100;
    else
        T=1/125;
    end
    N1=floor(t1/T)-20;
    N2=ceil(t2/T)+20;
    n=N1:N2;
    nT=N1*T:T:N2*T;
    xnT=80*sinc(100*nT)+25*sinc(100*nT-1)+90*sinc(20*nT-0.8)+25*sinc(50*nT-3)+80*sinc(100*nT-8);
    tm=meshgrid(t,1:size(n,2));
    nTm=meshgrid(nT,1:size(t,2))';
    xnTm=meshgrid(xnT,1:size(n,2))';
    xr=sum(100*T*xnTm.*sinc(100*(tm-nTm)));
%     plotting statements
end;

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