How do we take turn this into a qspk?

bpsk modulation and demodulation clear all; close all; %number of bits Noit-1e5; %Generate 1 and Os x-round (rand (1, Noit)) %find indices of zeros zero ind-find (x--0); %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 sn= [ ] ; for mn-1:4, twin-(mn-1) *T+0:1/ (100+f0) :mn * T ; %time widow for each bit tn-[tn, twin]; total time for three bits sn-[sn, x (mn) *cos (2*pi*f0*twin) waveform for three bits end fiqure (1); plot tn, sn, ' Linewidth' , 2) ; %Plot BPSK modulated signal xlabel ('time ylabel ('BPSK modulated signal'); bpsk modulation and demodulation clear all; close all; %number of bits Noit-1e5; %Generate 1 and Os x-round (rand (1, Noit)) %find indices of zeros zero ind-find (x--0); %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 sn= [ ] ; for mn-1:4, twin-(mn-1) *T+0:1/ (100+f0) :mn * T ; %time widow for each bit tn-[tn, twin]; total time for three bits sn-[sn, x (mn) *cos (2*pi*f0*twin) waveform for three bits end fiqure (1); plot tn, sn, ' Linewidth' , 2) ; %Plot BPSK modulated signal xlabel ('time ylabel ('BPSK modulated signal')