Blind Decoding Based on Independent Component Analysis for a Massive MIMO Uplink System in Microcell Rician/Rayleigh Fading Channels

In a massive multiple-input-multiple-output (MIMO) uplink system, the pilot sequence reuse in neighboring cells causes pilot contamination, causing the decoding performance to degrade significantly. In this paper, a blind decoding method based on independent component analysis (ICA) is proposed without using pilot sequences. The proposed blind decoding method uses ICA to separate the received signals (from in-cell and neighboring cells) and estimate channels. The energy levels of the estimated channels are used to differentiate an in-cell signal from neighboring cell signals. The analytical performance results of the blind decoding method are derived. Numerical results show that the proposed blind decoding scheme outperforms minimum-mean-square-error (MMSE) decoding and zero-forcing (ZF) decoding with imperfect channel state information (CSI). The proposed scheme has only a negligible performance loss compared with MMSE decoding and ZF decoding with perfect CSI.