Abstract: WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX technology enables ubiquitous delivery of wireless broadband service for fixed and/or mobile users. Routing is the key issue of WiMAX. Various modulation techniques have been studied. It was mandatory to evaluate the performance of WIMAX 802.16 technology by evaluating the Bit-Error Rate (BER) of OFDM physical layer under different modulation schemes and channel conditions. In this work, with the performance investigation of the WIMAX system under different applications generating high load data traffic, various modulation schemes like BPSK, QPSK, QAM 64 etc. were introduced. The performance of WIMAX physical layer is analysed based on the simulation results of Bit-Error Rate (BER) and Signal-to-Noise Ratio (SNR) and the results are represented in the form of tables and graphs. Creating the simulation scenario that is equivalent to real world is the first step of simulation. In this work, various modulation techniques used by OFDM physical layer of WIMAX 802.16 are implemented. To generate data in the network, applications generating high load data traffic at VBR will be designed. A discrete event simulator called OPNET (Optimized Network Engineering Tool) Modeller version 14.0 is used to implement all the mechanisms by using the process models provided by the library of the simulator. In the last various performances evaluation metrics are used to gather the results of Bit Error Rate (BER) and Signal to Noise Ratio (SNR) in tabular and graphical form and conclusion is drawn based on the gathered results.
Keywords: IEEE 802.16 WiMAX, Physical layer, OPNET, Modulation techniques, Bit Error Rate.