Abstract
Today's demand in wireless communication system is high throughput with constant connectivity. One of the promising solutions for this is adaptive modulation techniques. As mobile user in mobility he/she moves towards or goes away from the access points or transmitter. At the same time there are changes in signal quality because of changing SNR due to movements. Due to that quality of services (QoS) are affected. According to the changing SNR if modulation schemes are changed then it's possible to maintain constant BER. In this paper we have used this concept in modelling WiMAX IEEE 802.16 system having Multiple Input Single Output (MISO) channel with adaptive modulation and simulated the model with real time changing SNR (which indicates movement) simultaneously changing the modulation scheme according to SNR. Results are observed and found BER constant which satisfies the objectives.