Improving BER of WiMAX using Interference Mitigation Techniques

New Generation Wireless Networks is still confront the disputes such as resource sharing, channel or bandwidth allocation, synchronization, spectrum efficiency, and interference a major concern among all. Orthogonal Frequency Division Multiplexing (OFDM) is a prevailing technology that is widely adopted by current 4G and 5G wireless communication as it can certainly resolves many issues of wireless networks such as data rates and interferences. The paper introduces three types of interferences - Inter Symbol Interference (ISI), Inter Carrier Interference (ICI), and Co- Channel Interference (CCI) that greatly clog our Bit Error Rate (BER). This paper had taken World Wide Interoperability for Microwave Access (WiMAX) as our 4G wireless application that works with OFDM and try to reduce its BER by using interference mitigation techniques such as Wavelet and Space Time Block Code (STBC). Furthermore, WiMAX physical layer is described with its interferences and relevant solution, also the advantage of Wavelet transform in contrast to Fourier transform and its comparison is shown in terms of BER.