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arXiv · 2507.08947

A joint channel estimation and beamforming separation principle for massive MIMO systems

Lorenzo Miretti·Slawomir Stańczak·Giuseppe Caire
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Abstract

We demonstrate that separating beamforming (i.e., downlink precoding and uplink combining) and channel estimation in multi-user MIMO wireless systems incurs no loss of optimality under general conditions that apply to a wide variety of models in the literature, including canonical reciprocity-based cellular and cell-free massive MIMO system models. Specifically, we provide conditions under which optimal processing in terms of ergodic achievable rates can be decomposed into minimum mean-square error (MMSE) channel estimation followed by MMSE beamforming, for both centralized and distributed architectures. Applications of our results are illustrated in terms of concrete examples and numerical simulations.

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Lorenzo Miretti, Slawomir Stańczak, Giuseppe Caire. 2025-07-11. A joint channel estimation and beamforming separation principle for massive MIMO systems. https://arxiv.org/abs/2507.08947

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