Noncoherent multi-user MIMO communications using covariance CSIT

Kurisummoottil Thomas, Christo; Tabikh, Wassim; Slock, Dirk TM; Yuan-Wu, Yi
ASILOMAR 2017, Invited paper in Asilomar Conference on Signals, Systems, and Computers, October 29th-November 1st 2017, Pacific Grove, CA, USA

The Multi-User downlink, particularly in a MultiCell Massive MIMO setting, requires enormous amounts of instantaneous CSIT (Channel State Information at the Transmitter(
s)), iCSIT. Here we focus on exploiting channel covariance CSIT (coCSIT) only. In particular multipath induced structured low rank covariances are considered that arise in Massive MIMO and mmWave settings, which we call pathwise CSIT (pwCSIT).
The resulting non-Kronecker MIMO channel covariance structures lead to a split between the roles of transmitters and receivers in MIMO systems. For the beamforming optimization, we consider a minorization approach applied to the Massive MIMO limit of the Expected Weighted Sum Rate. Simulations indicate that the pwCSIT based designs may lead to limited spectral efficiency loss compared to iCSIT based designs, while
trading fast fading CSIT for slow fading CSIT. We also point out that the pathwise approach may lead to distributed designs with only local pwCSIT, and analyze the sum rates for iCSIT and pwCSIT in the low and high SNR limits.

Invited paper in a conference
Pacific Grove
Communication systems
Eurecom Ref:
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