Link Adaptation for Mobile Terminal

Abstract

WiMAX has attracted a lot of attention recently in the telecommunication community including researchers, product developers and service providers. Numerous papers have been published on various design issues of WiMAX networks. Researchers made a lot of researches to develop and evaluate different Link Adaptation algorithms for enhancing the performance of the WiMAX systems. Researchers motivated by the demand of seamless mobility. The IEEE 802.16e or mobile WiMAX opens a new door of possibility of mobile broadband. Hence, it is a strong competitor to the existing mobile communication systems ( 3G, and 4G). It is expected that IEEE 802.16e will be the standard for future mobile WiMAX technology that could greatly increase the channel capacity without additional spectral resources. At this moment, mobile WiMAX or IEEE 802.16e is one of the hottest areas of research In this thesis Link Adaptation (LA) algorithm was proposed for the mobile terminals which ware supported by (mobile) WiMAX network. The role of link adaptation (LA) was very important because it controls the physical layer throughput. Therefore, all the higher layers are affected by LA. The main function of LA algorithm was to select an appropriate burst profile, Forward Error Correction Block Error Rate (FBER) was chosen as constraint for the performance of LA. LA algorithm used a static threshold table of SNR per symbol and considers MIMO (Multiple Input Multiple Output) channel correlation. SNR (Signal to Noise Ratio) was dynamically adjusted the before looking at the table based on mobility state. The performances of the proposed LA algorithm were evaluated through numerical results used comparison and graphs. According to numerical results, the proposed LA algorithm was able to maintain a certain level quality of service (QoS) and it can be considered as reference for any further research in Link Adaptation field.