Optical receiving methods and systems are disclosed. A computer implemented process translates the high order complex geometry embodied in CAD software to the SBCG format. The driving circuit is configured to generate the control signal so as to make a period for switching the first switch from a conductive state to a non-conductive state longer than a period for switching the first switch from the non-conductive state to the conductive state. The sampling frequency may be determined such that an aliasing product of the undersampling occurs at a frequency of the reference signal.