The main objectives of the thesis and the related research are to improve state-of-the-art techniques in the digital subscriber line (DSL) systems and to develop a novel method operating on telecommunication network physical layer of DSL systems. The new method is based on the application of the multiple-input multiple-output (MIMO) principles commonly used in todays wireless communication systems. It results in direct application of the new technique exploiting MIMO features in future implementations of the DSL physical layer.