cadence pss analysis

I have been using a pulse source to spike the vdd in order to jump start the oscillations in the LC VCO. While doing the PSS analysis it shows an error "Input periodic sources can't be used in autonomous circuits". Please help.
Thanks in advance.

Use a VPWL/IPWL or use initial condition to start the oscillations. You cant use periodic sources here.

Thanks saro_k_82, problem got solved with your suggestion, thanks again :)