This article proposes an idea regarding the generation distance preserving mapping (DPM) from the solution set of discretetime state equation. A modified linear block code is proposed from such DPM for which the distance preserving property is observed. The designed code is generalized from the nth order solution space. As the code words of such established codes are very unique with regards to their bit positions, it is easy to solve the decoding problem at the receiver end. This correspondence also proposes an Intelligent Decoder (ID) along with the construction of decoding algorithm. Also, the methodology is developed for increasing the minimum distance between the codewords for the codes designed using DPM. The performance of the designed codes has been carried out using simulation.