Methods and systems for generating illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter control signals in a three-dimensional image-capturing system with one or more frequency synthesizers is disclosed. The illumination modulation signals, image intensifier gain modulation signals, and image sensor shutter signal are all coherent with one another, being derived from a common clock source. The use of frequency synthesizer concepts allow for the use of rapid modulation phase changes for homodyne operation, and further allow the use of rapid modulation frequency changes to mitigate the effects of inter-camera interference.