Link Adaptation Algorithm in Wireless Networks

• Main Authors: Kuang-Wei Chang, 張光為
• Other Authors: Tsung-Nan Lin
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/89593134978724848195

碩士 === 國立臺灣大學 === 電信工程學研究所 === 96 === In recent years, IEEE 802.11 Wireless local area networks (WLANs) have become the most popular technology due to the wide deployment in many areas, such as home, office, airport, and so on. IEEE 802.11 PHY supports multiple transmission rates by using different Modulation and Coding Schemes (MCS) to achieve better performance. Different rate adaptation algorithms affect the performance significantly in all wireless networks. In this paper, we propose a novel algorithm, and compare it with several other algorithms. The basic idea of our algorithm is to choose the MCS with the shortest time to transmit a frame successfully. In addition, most algorithms don’t take the effect of small-scale fading into account, and they only focus on collisions or corruptions. In this way, those algorithms may not attain the best performance in real life. We make some comments on all other algorithms and provide more complete guidelines to design an algorithm. We evaluate the performance of the proposed algorithm via computer simulation. From simulation results, we can obviously see that our algorithm really performs better than the other algorithms. In addition, our algorithm only uses the available information locally like ACK, consecutive failure times, to choose suitable rate. Therefore our algorithm can easily implement in all 802.11-based devices.