Performance Evaluation of Adaptive Modulation Techniques and Offered Load in OFDM-based WiMAX Network by Considering Cyclic Prefix

WiMax uses orthogonal frequency division multiple access technique in wireless communication. Orthogonal frequency division multiple access (OFDM) is what puts the max in WiMAX, OFDM delivers a wireless signal much farther with less interference. This technique uses Adaptive modulation coding (AMC) on physical layer of WiMAX. Adaptive modulation technique uses the concept of cyclic prefix that adds additional bits at the transmitter end. The receiver removes these additional bits. Cyclic Prefix is used to combat intersymbol inter-ference (ISI) and intercarrier interference (ICI) introduced by the multipath fading channel. This paper investigates the performance of WiMAX network by varying physical layer parameter such as modulation and coding scheme and cyclic prefix. It also investigates the performance of WiMAX network by increasing traffic (number of downloading nodes) in network with different cyclic prefix.The performance of WiMAX network is measured in terms of throughput and goodput Index Terms— Downlink (DL), Adaptive Modulation techniques, IEEE-802.16, OFDMA, Cyclic Prefix, Throughput, Goodput