Impact of Spatial Filtering on Distortion from Low-Noise Amplifiers in Massive MIMO Base Stations
Artikel i vetenskaplig tidskrift, 2018

Because of the large number of antennas at the base station, the power consumption and cost of the low-noise amplifiers (LNAs) can be substantial. Therefore, we investigate the feasibility of inexpensive, power efficient LNAs, which inherently are less linear. To characterize the nonlinear distortion, the LNAs are described using a polynomial model, which allows for the derivation of the second-order statistics of the distortion. We show that some terms of the distortion from the LNAs combine coherently, and that the SINR of the symbol estimates therefore is limited by the linearity of the LNAs. Furthermore, the impact of a strong transmitter in the adjacent frequency band is investigated. The second-order statistics show how the power from that transmission leaks into the main band and interferes with the symbol estimates. The term that scales with the cube of the power received from the blocker can be filtered out by spatial processing. Only the coherent term that scales with the square of the power remains. Nonlinear distortion from the LNAs can be reduced by spatial processing in massive MIMO. However, it does not vanish as the number of antennas is increased.

MIMO communication

Base stations

nonlinearities

MIMO systems

antenna arrays

Correlation

amplifiers

nonlinear distortion

Receivers

Nonlinear distortion

Hardware

Författare

Christopher Mollen

Linköpings universitet

Ulf Gustavsson

Ericsson AB

Thomas Eriksson

Chalmers, Elektroteknik, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Erik G. Larsson

Linköpings universitet

IEEE Transactions on Communications

00906778 (ISSN)

Vol. 66 12 6050-6067

Styrkeområden

Informations- och kommunikationsteknik

Ämneskategorier

Telekommunikation

Signalbehandling

DOI

10.1109/TCOMM.2018.2850331

Mer information

Senast uppdaterat

2019-03-19