MI-NLMS adaptive beamforming algorithm for OFDM system

OFDM is a multi-carrier technique that recently has received more attention for high speed wireless communication. A matrix inversion normalized least mean square (MI-NLMS) adaptive beamforming algorithm was developed for OFDM system. The algorithm was developed by combining the sample matrix inversion (SMI) and the normalized least mean square (NLMS) algorithms taking the individual good aspects of both algorithms; the block adaptive and sample by sample techniques. Based on the obtained results, it appears that the MI-NLMS has more reliable and faster convergence compared to the least mean square (LMS) algorithm. Simulation results showed that bit error rate (BER) improves 81 % by using 8 elements antenna array compared to single element antenna and 92% at 256 pilots compared to BER at 32 pilots for the MI-NLMS algorithm.