Hybrid Shft Keying PSK & FSK using MATLAB

clc
clear all
close all
clf
m=mod(randperm(4),2)  % this generates the 4 random bits which are binary
l=length(m)
t=[0.01:0.01:l]
for i=1:1:l
a((i-1)*100+1:i*100)=m(i)
end
figure(1)
plot(a,'red')
title('message signal')
f1=4
f2=3
c=sin(2*pi*(f1+(a.*f2)).*t+(not(a).*pi)) %carrier which will be transmitted over channel
figure(2)
plot(c,'black')
title('hybrid shift keying combination of FSK PSK')