Link-to-System Interfaces for System Level Simulations Featuring Hybrid ARQ

Abstract

Within the continuous evolution of wireless communications, new and ambitious requirements are planned to be met by next generation of mobile communications. In order to achieve those requirements, new technologies and mechanisms that work well over broadband frequency, like OFDM and OFDMA, need to be investigated, developed and tested in simulators. New cellular systems designs are based on exploiting instantaneous channel conditions, improving the system performance. Due to this, system level simulations must support a Physical Layer (PHY) abstraction which accurately predicts the instantaneous performance of the link layer. In order to accomplish this, a new link-to-system (L2S) interface has been developed and implemented in OpenWNS, a system level simulator for evaluation of OFDM systems developed at RWTH, Aachen. This interface is mainly realized through a set of mapping mechanisms, used to provide a BLER given a received coded block SINR. Together with the theoretical study and evaluation of these mappings mechanisms, this thesis will analyze and evaluate Hybrid Automatic Repeat Request mechanisms (H-ARQ), and how these protocols can be implemented in system level simulators working together with the L2S interface. This thesis shows how the new L2S interface is more accurate than past approaches, providing a gain of around 3 dB. Concerning H-ARQ protocols, the results show how the use of these new techniques provides a considerable gain with respect to normal ARQ or not using any such technique