How to plot a changing frequency gaussian pulse train?

hi,

I have this code -

t = 0 : 1/50E3 : 10e-3;
d = [0 : 1/1E3 : 30e-3]';
y = pulstran(t,d,'gauspuls',10e3,0.5); 
plot(t,y)

which is supposed to generate a gaussian pulse train of 30 kHz.

How can I increment each pulse by 10Khz, that is first one being 30 next 40 and so on.

Thanks,

Rohan