Robust blind beamforming for LTE in multipath environment

Abstract

A robust blind beamforming algorithm is proposed for Long Term Evolution (LTE) system in the uplink direction using a Uniform Linear Array (ULA) at the base station (eNodeB) in the multipath environment. There is no information about the incoming signals, so a robust estimation of the Direction of Arrival (DOA) of the received signals is performed first. The robust Re-iterative Superresolution (RISR) DOA estimation algorithm is implemented to estimate the DOA and to separate the coherent signals impinging from different directions due to multipath, then a robust RISR beamforming is proposed for each estimated direction, followed by time delay estimation of signals using the correlation function between each two signals to obtain the signal in the desired direction (direct signal). Finally, applying the beamforming in the desired direction to correctly receive the signal and reject the multipath effect as well as enhancing Bit error rate (BER). The results show the effectiveness of the proposed algorithm when compared to other traditional beamforming algorithms especially for coherent sources.