Scattered Mapping Mechanism for Fault-Tolerant Transmission in WiMAX Networks

• Main Authors: Syao-Syuan Liu, 劉劭軒
• Other Authors: JenHui Chen
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/41098755030791389274

碩士 === 長庚大學 === 資訊工程研究所 === 94 === In wireless metropolitan area networks (WMANs), the medium access control (MAC) layer and the physical (PHY) layer in IEEE 802.16 standard plays the main role of determining the efficiency of controlling the limited connection bandwidth of whole wireless channels. Also such a broadband wireless networks could provide more bandwidth than the traditional wireless networks. Considering the interference and fading problem to the subcarrier in the PHY layer as well as the subchannel the MAC layer. We will discusses how to eliminate the interference and fading effect of the wireless network systems based on orthogonal frequency-division multiple access (OFDMA) scheme. The OFDMA scheme is regarded as a solution for improving the performance of wireless broadcasting systems. It is based on orthogonal frequency-division multiplexing (OFDM) and inherits its immunity to inter-symbol interference (ISI), intercarrier interference (ICI), and frequency selective fading. Notwithstanding some mechanisms are investigated to solve the inevitable intra-interferences, there still has many external interferences, which may corrupt the ongoing transmissions. To alleviate this effect, we propose scattered mapping mechanism (SMM) in the OFDMA frame based on the IEEE 802.16 standard. This mechanism will rearrange the permutation of slots in each subframe, which will improve the fault tolerance ability and provide the quality of security. For the purpose, we will demonstrate the numerical results to prove our method indeed improve the performance over the broadband wireless access network over OFDMA.