The following code from Matlab is of BPSK modulation and demodulation. I need to generate QPSK symbols from this code. Any help would be appreciated.

8bpsk modulation and demodulation clear all; close all; %number of bits Noit-le5; %Generate 1 and 0s x-round (rand (1,Noit)); %find indices of zeros zero ind-find (x0); %set all zero values of x to -1 x(zero ind)=-1; %generate a waveform T=0.002; % symbol duration in sec t=0: 1/ (100+f0) :T; %time window, the duration between two samples is 1/(100*f0) Plot symbol waveform s-cos (2*pi*f0*t); plot (t,s) %Plot BPSK modulated signal for first five bits %initialize total time and symbol waveform corresponding to five bits tn=[ ] ; for mn=1:4, twin (mn-1 ) *T+0:1/(100H0):mn *T ; %time widow for each bit tn=[tn, twin); %total time for three bits sn-[sn, x(mn ) *cos ( 2 * pi*E0*twin)]; %total waveform for three bits end figure(1); plot ( tn, sn, ' Linewidth' , 2 ) ; %Plot BPSK modulated signal xlabeltime' ylabel( 'BPSK modulated signal 8bpsk modulation and demodulation clear all; close all; %number of bits Noit-le5; %Generate 1 and 0s x-round (rand (1,Noit)); %find indices of zeros zero ind-find (x0); %set all zero values of x to -1 x(zero ind)=-1; %generate a waveform T=0.002; % symbol duration in sec t=0: 1/ (100+f0) :T; %time window, the duration between two samples is 1/(100*f0) Plot symbol waveform s-cos (2*pi*f0*t); plot (t,s) %Plot BPSK modulated signal for first five bits %initialize total time and symbol waveform corresponding to five bits tn=[ ] ; for mn=1:4, twin (mn-1 ) *T+0:1/(100H0):mn *T ; %time widow for each bit tn=[tn, twin); %total time for three bits sn-[sn, x(mn ) *cos ( 2 * pi*E0*twin)]; %total waveform for three bits end figure(1); plot ( tn, sn, ' Linewidth' , 2 ) ; %Plot BPSK modulated signal xlabeltime' ylabel( 'BPSK modulated signal