Based on the principle of coherent noise suppression using a ring light source, a virtual ring light source generated by a rotating optical wedge is designed for a typical Fizeau interference system. The selection of wedge angle for the optical wedge is discussed, the random noise points and coherent noise sources of the virtual ring-light-source Fizeau interference system are simulated, and the interference fringe diagrams of the point source and ring source modes are compared. The results show that the virtual ring light source can suppress the system noise efficiently while maintaining a better contrast of the interference fringes.