Channel estimation is a bottleneck for massive-MIMO system both TDD and FDD, because high spatial resolution is required enough channel estimation precision that is challenge problem in high noise environment, where noise includes thermal noise, intra-cell / inter-cell interference, pilot contamination (because of not enough orthogonal pilots for measurements), hardware impairement effects (PIM, etc.). And if massive-MIMO concept, which is based on coherent processing allows to obtain significant gain for data layer, it cannot be applied steight forward way for channel estimation, because basic CSI is estimated antenna port-by-antenna port and there is no gain from massive-MIMO at channel estimation stage.
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AuthorPrincipal Engineer in wireless communication for PHY and MAC layers. Archives
December 2018
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