Performance of Adaptive Beamforming Algorithm for Angle Separation and Interference Power Level

摘要

The performance of matrix inversion normalized least mean square (MI-NLMS) adaptive beamforming algorithm for angle separation and interference power level is presented in this paper. The MI-NLMS adaptive beamforming algorithm is implemented for smart antenna in orthogonal frequency division multiplexing (OFDM) system, using frequency domain beamforming approach to improve the performance. The proposed algorithm for adaptive beamforming in OFDM system was developed by combining the sample matrix inversion (SMI) and the normalized least mean square (NLMS) algorithms, taking the individual good aspects of both the algorithms: the block adaptive and sample by sample techniques. Based on the obtained results, it appears that the MI-NLMS has low Bit Error Rate (BER) compared to the Least Mean Square (LMS) algorithm in terms of the angle separation for the desired user and interferer and interference power level. The MI-NLMS provides a very good interference suppression capability and better BER rate which is 84.50% compared to LMS algorithm, at an interference level of 0 dB.