"Wireless and Mobile Communications LabAssignment:a. Create an m file b. Implement a CDMA Transmitter 1. Generate Data Bits for four users 2. Apply BPSK to each 3. Convert the bits into pulse. 4. Generate four different Spread Codes. 5. Implement CDMA technique for four users. c. Plot all the results.MATLAB Solution:Generated bits for 4 usersu1 = randi([0,1], 1, 15);u2 = randi([0,1], 1, 15);u3 = randi([0,1], 1, 15);u4 = randi([0,1], 1, 15);U_1=2*u1-1;U_2=2*u2-1;U_3=2*u3-1;U_4=2*u4-1;Making all the four users data a square wave squarewave=ones(1,8);U1 = [];for i = 1:1:15n = U_1(i)*squarewave;U1 = [U1 n];endU2 = [];for i = 1:1:15n = U_2(i)*squarewave;U2 = [U2 n];endU3 = [];for i = 1:1:15n = U_3(i)*squarewave;U3 = [U3 n];endU4 = [];for i = 1:1:15n = U_4(i)*squarewave;U4 = [U4 n];endCodecsSC1=[1,1,1,1,1,1,1,1];SC2=[1,1,1,1,-1,-1,-1,-1];SC3=[1,1,-1,-1,1,1,-1,-1];SC4=[1,1,-1,-1,-1,-1,1,1];Adding the codecs to the square wavesUSC1=[];for i=1:1:15n = U1((8*(i-1)+1):(8*i)).*SC1;USC1 = [USC1 n];endUSC2=[];for i=1:1:15n = U2((8*(i-1)+1):(8*i)).*SC2;USC2 = [USC2 n];end USC3=[];for i=1:1:15n = U3((8*(i-1)+1):(8*i)).*SC3;USC3 = [USC3 n];endUSC4=[];for i=1:1:15n = U4((8*(i-1)+1):(8*i)).*SC4;USC4 = [USC4 n];endSum of all coded data streamsUSC=USC1+USC2+USC3+USC4;Case 1 (Without Noise and Interference)R1=[];for i=1:1:15n=USC((8*(i-1)+1):(8*i)).*SC1;if (sum(n)>0)R1=[R1 1];elseR1=[R1 0];endendR2=[];for i=1:1:15n=USC((8*(i-1)+1):(8*i)).*SC2;if (sum(n)>0)R2=[R2 1];elseR2=[R2 0];endendR3=[];for i=1:1:15n=USC((8*(i-1)+1):(8*i)).*SC3;if (sum(n)>0)R3=[R3 1];elseR3=[R3 0];end endR4=[];for i=1:1:15n=USC((8*(i-1)+1):(8*i)).*SC4;if (sum(n)>0)R4=[R4 1];elseR4=[R4 0];endendCase 2 (Adding Noise)NUSC=awgn(USC,20);NR1=[];for i=1:1:15n=NUSC((8*(i-1)+1):(8*i)).*SC1;if (sum(n)>0)NR1=[NR1 1];elseNR1=[NR1 0];endendNR2=[];for i=1:1:15n=NUSC((8*(i-1)+1):(8*i)).*SC2;if (sum(n)>0)NR2=[NR2 1];elseNR2=[NR2 0];endendNR3=[];for i=1:1:15n=NUSC((8*(i-1)+1):(8*i)).*SC3;if (sum(n)>0)NR3=[NR3 1];elseNR3=[NR3 0];endendNR4=[];for i=1:1:15n=NUSC((8*(i-1)+1):(8*i)).*SC4;if (sum(n)>0)NR4=[NR4 1];elseNR4=[NR4 0]; endendBit Error Rateerror1=nnz(u1-NR1);BER1=(error1/4)/15error2=nnz(u2-NR2);BER2=(error2/4)/15error3=nnz(u3-NR3);BER3=(error3/4)/15error4=nnz(u4-NR4);BER4=(error4/4)/15BER1 = 0BER2 = 0BER3 = 0BER4 = 0Case 3 (interference)IUSC=USC+USC3;IR1=[];for i=1:1:15n=IUSC((8*(i-1)+1):(8*i)).*SC1;if (sum(n)>0)IR1=[IR1 1];elseIR1=[IR1 0];end endIR2=[];for i=1:1:15n=IUSC((8*(i-1)+1):(8*i)).*SC2;if (sum(n)>0)IR2=[IR2 1];elseIR2=[IR2 0];endendIR3=[];for i=1:1:15n=IUSC((8*(i-1)+1):(8*i)).*SC3;if (sum(n)>0)IR3=[IR3 1];elseIR3=[IR3 0];endendIR4=[];for i=1:1:15n=IUSC((8*(i-1)+1):(8*i)).*SC4;if (sum(n)>0)IR4=[IR4 1];elseIR4=[IR4 0];endendBit Error Rateerror1=nnz(u1-IR1);BER1=(error1/4)/15error2=nnz(u2-IR2);BER2=(error2/4)/15error3=nnz(u3-IR3);BER3=(error3/4)/15error4=nnz(u4-IR4);BER4=(error4/4)/15BER1 = 0BER2 = 0 BER3 = 0BER4 = 0Case 4 (Interference and Noise)NIUSC=awgn(USC,20)+USC3;NIR1=[];for i=1:1:15n=NIUSC((8*(i-1)+1):(8*i)).*SC1;if (sum(n)>0)NIR1=[NIR1 1];elseNIR1=[NIR1 0];endendNIR2=[];for i=1:1:15n=NIUSC((8*(i-1)+1):(8*i)).*SC2;if (sum(n)>0)NIR2=[NIR2 1];elseNIR2=[NIR2 0];endendNIR3=[];for i=1:1:15n=NIUSC((8*(i-1)+1):(8*i)).*SC3;if (sum(n)>0)NIR3=[NIR3 1];elseNIR3=[NIR3 0];endendNIR4=[];for i=1:1:15n=NIUSC((8*(i-1)+1):(8*i)).*SC4;if (sum(n)>0)NIR4=[NIR4 1];elseNIR4=[NIR4 0]; "