Tutorial: Towards 4G wireless systems (WIMAX &LTE) BR” (4GWS)

Fourth generation wireless systems have the potential to change the way we communicate and collaborate to accomplish business needs. The need of the hour is to provide a unified system that provides a seamless user experience on the move. Systems beyond IMT-2000 claim to have the capability to support services/applications that demand very stringent performance requirements. Standardization bodies are trying to achieve this by adopting cutting edge technologies and strategies that have evolved over the last few decades. WiMAX (802.16m) and LTE-Advanced (UMTS Release-10) are the mostly likely candidates to meet ITU defined IMT-Advanced performance goals. Both WiMAX and LTE have lot of technical similarities primarily on the radio access network side. Both have adopted an OFDMA based physical layer. Channel based scheduling algorithms; link adaptation techniques and hybrid ARQ are the common trait in these systems. Adaptive modulation and coding scheme (AMC) is another popular feature in this system which aims to exploit the channel conditions and assignment, to improve channel capacity. The performance of these systems is further augmented by embracing multiple antenna techniques. Flat network architecture and All-IP network are the buzzwords across standards to achieve throughput expansion and to reduce the capital and operational expenditure. The cutting edge technologies/strategies listed above are critical to achieve the performance target set through IMT-Advanced. This tutorial presentation would provide a detailed view of the important technologies behind 4G systems and how it´s proposed to be implemented in IEEE-802.16m and LTE-Advanced.