Out-of-band radiation measure for MIMO arrays with beamformed transmission
Paper in proceedings, 2016

The spatial characteristics of the out-of-band radiation that a multiuser MIMO system emits, due to its power amplifiers (modeled by a polynomial model) being nonlinear, are studied by deriving an analytical expression for the continuous-time cross-correlation of the transmit signals. It is shown that, at any spatial point and on any frequency, the received power averaged over many channel realizations from a MIMO base station is the same as from a SISO base station when the two radiate the same amount of power. For a specific channel realization however, the received power can deviate from this average. We show that the deviations from the average are small in a MIMO system with multiple users and that the deviations can be significant with only one user. Using an ergodicity argument, we conclude that out-of-band radiation is less of a problem in massive MIMO, where precoding and array gain let us reduce the total radiated power compared to SISO systems. The requirements on spectral regrowth can therefore be relaxed in MIMO systems without causing more total out-of-band radiation.

ACLR

power amplifier

out-of-band radiation

massive MIMO

spectral regrowth

nonlinearity

MIMO

Author

Christopher Mollen

Linköping University

Ulf Gustavsson

Ericsson AB

Thomas Eriksson

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

E. G. Larsson

Linköping University

2016 IEEE International Conference on Communications, ICC 2016, Kuala Lumpur, Malaysia, 22-27 May 2016

1550-3607 (ISSN)

Art. no. 7511629-

Areas of Advance

Information and Communication Technology

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/ICC.2016.7511629

ISBN

978-1-4799-6664-6

More information

Latest update

11/19/2018