The use of repeater for the support of high rate data transmission and the extension of cell coverage is imperative for the Wibro system,which based on the IEEE 802.16e standardization.Generally,if the separation between transmitting and receiving antennas is not sufficient,the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be occurr.Hence,the Interference Cancellation System(ICS)should be implemented as the important part of the repeater system for the mobile cellular systems in order to eliminate unwanted signals from the corrupted signals in the receiver.In this paper,we propose an adaptive technique for the Least Mean Square(LMS)-based interference cancellation methods by changing the step size according to the variation of channel environment in order to improve the performance degradation which occurrs by using the fixed step size approach.Simulation results show that the proposed scheme attains a little lower Ber Error Rate(BER)performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques.The proposed scheme can be applied to other Orthogonal Frequency Division Multiple(OFDM)-based cellular systems and also be expected to achieve a similar performance improvement to IMT-advanced system,which is called as the next generation mobile communication standards. The use of repeater for the support of high rate data transmission and the extension of cell coverage is imperative for the Wibro system, which based on the IEEE 802.16e standardization. Normally, if the separation between transmitting and receiving antennas is not sufficient, the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be generated .ence, the Interference Cancellation System (ICS) should be implemented as the important part of the repeater system for the mobile cellular systems in order to eliminate unwanted signals from the corrupted signals in the receiver. In this paper, we propose an adaptive technique for the Least Mean Square (LMS) -based interference cancellation methods by changing the step size according to the variation of channel environment in order to improve the performance degradation which occurrs by using the fixed step size approach. Simulation results show that the proposed scheme attains a little lower Ber Err or BER (BER) performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques. The proposed scheme can be applied to other Orthogonal Frequency Division Multiple (OFDM) -based cellular systems and also be expected to achieve similar performance improvement to IMT-advanced system, which is called as the next generation mobile communication standards.