This paper was prepared as simulation study of interference decreasing using AMC algorithm where a comparison between ordinary modulation techniques is compared to Multicarrier Modulation MCM and adaptive modulation, results of the simulation was observed and compared for above scenarios. | International Journal of Computer Networks and Communications Security VOL. 3, NO. 9, SEPTEMBER 2015, 378–383 Available online at: E-ISSN 2308-9830 (Online) / ISSN 2410-0595 (Print) Decrease Interference Using Adaptive Modulation and Coding Osman Mudathir Elfadil1, Y. M. Alkasim2 and Rayan. A. Ali3 1, 2, 3 Department of Electrical and Electronics Engineering, Omdurman Islamic University E-mail: 1osman7677@, 2yasserm89@, ABSTRACT The limitations of channel bandwidth, time varying channel and fading are significant and fundamental problem in wireless communication, which leads to the difficulty of providing high Quality of Service. The traditional wireless communication systems are designed to provide good quality of services at the worst channel conditions. Wherein any attempts to increase the channel bandwidth, interference arises along with these attempts. And result in inefficient utilization of the full channel capacity. One of the efficient techniques to overcome to these problems is known as adaptive modulation and coding (AMC). This paper was prepared as simulation study of interference decreasing using AMC algorithm where a comparison between ordinary modulation techniques is compared to Multicarrier Modulation MCM and adaptive modulation, results of the simulation was observed and compared for above scenarios. Keywords: MCM, SCM, OFDM, AMC, BER, AWGN, Rayleigh. 1 INTRODUCTION Communication bandwidth is the range of frequencies passed by a wireless or wired medium, the bitrate supported is generally proportional to the bandwidth, and spectral efficiency is the ratio of bitrate to bandwidth. On these media spectral efficiency is limited by interference. In wireless radio any user’s communications typically share the same radio channel one user’s communication becomes unwanted interference to another user’s legitimate communication user’s cannot simply increase their transmitted power to overcome