For the feasible solution space reduction different limitation on solution is applied. Limitations are selected according to the signal or image properties. From all class of feasible solutions only few are selected, which qualify to the positivity requirement. In This work the influence of solution limitation on the signal restoration method properties was shown and computer simulation was performed. For estimation of limitation influence on restoration process the numeric simulation was made. Pulse signal, distorted by linear invariant to shift system with bounded pass band were restored with application of different limitations.