// Exa 11.2 // To show that the transmitted signals to mobiles 1, 2, and 3 are recovered at the mobile receivers by despreading the resultant signal z(t). clc; clear all; //solution disp("From figure 11.4, we note that transmitted data for mobile1 as [0 1 1 0 0 ], for mobile2 as [0 0 1 0 0 ] and for mobile3 as [0 1 0 0 1] "); disp("From figure 11.5 we get resultant demodulated signal at a mobile "); Rx={[1 1 1 1 -3 1];[1 -3 1 1 1 1 ];[1 -3 1 1 1 -3];[1 -3 1 1 1 1];[-1 3 3 -1 3 -1]};//Resultant demodulated signal at mobile disp(Rx); //from Figure 11.4 c1={[-1 -1 -1 -1 1 1];[1 -1 1 1 -1 -1];[1 -1 1 -1 -1 -1];[-1 1 1 1 -1 1];[1 -1 -1 1 -1 1]}; c2={[1 1 -1 1 1 -1];[-1 1 -1 1 -1 -1];[-1 -1 1 1 1 -1];[1 1 -1 -1 1 -1];[1 -1 -1 -1 -1 -1]}; c3={[-1 -1 1 -1 1 -1];[-1 -1 -1 1 1 1];[-1 1 1 -1 -1 1];[-1 1 -1 -1 -1 -1];[1 1 1 -1 1 1]}; //t={[1 2 3 4 5 6];[7 8 9 10 11 12];[13 14 15 16 17 18];[19 20 21 22 23 24];[25 26 27 28 29 30]}; //for Mobile 1 for i= 1:5 Demod1(i)=c1(i,1)*Rx(i,1)+c1(i,2)*Rx(i,2)+c1(i,3)*Rx(i,3)+c1(i,4)*Rx(i,4)+c1(i,5)*Rx(i,5)+c1(i,6)*Rx(i,6); if(Demod1(i)<0) B1(i)=1; else B1(i)=0; end end //for mobile 2 for i= 1:5 Demod2(i)=c2(i,1)*Rx(i,1)+c2(i,2)*Rx(i,2)+c2(i,3)*Rx(i,3)+c2(i,4)*Rx(i,4)+c2(i,5)*Rx(i,5)+c2(i,6)*Rx(i,6); if(Demod2(i)<0) B2(i)=1; else B2(i)=0; end end //for mobile 3 for i= 1:5 Demod3(i)=c3(i,1)*Rx(i,1)+c3(i,2)*Rx(i,2)+c3(i,3)*Rx(i,3)+c3(i,4)*Rx(i,4)+c3(i,5)*Rx(i,5)+c3(i,6)*Rx(i,6); if(Demod3(i)<0) B3(i)=1; else B3(i)=0; end end disp("Value of integration at end of bit period for mobile1"); disp(Demod1'); disp("Value of integration at end of bit period for mobile2"); disp(Demod2'); disp("Value of integration at end of bit period for mobile3"); disp(Demod3'); disp("The recovered signal at mobile 1 is "); disp(B1'); disp("The recovered signal at mobile 2 is "); disp(B2'); disp("The recovered signal at mobile 3 is "); disp(B3'); disp("In all cases, Recovered signal is negated value of transmitted signal")