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Noncoherent Detection in Massive MIMO Systems

Massive MIMO, where base stations are equipped with a very large number of receive antennas, is a promising approach to increase the spectral efficiency in non-cooperative multi-user MIMO systems. In this context, the biggest challenge is to perform accurate channel estimation in order to implement coherent detection. On the one hand, the required pilot signaling overhead significantly limits the number of served users. On the other hand, the complexity of channel estimation dramatically increases as the number of receive antennas and/or users increase. Exploiting the similarity of massive MIMO systems to impulse-radio ultra-wideband (IR-UWB) communications, we present noncoherent detection schemes for massive MIMO systems, which avoid explicit channel estimation. In particular, autocorrelation-based (sorted) decision-feedback differential detection is adopted to the system at hand.