US 11,668,740 B2
Over the air calibration and testing of beamforming-based multi-antenna devices in anechoic and non-anechoic environments
Marcus Grossmann, Friedrichroda (DE); Markus Landmann, Zeitz (DE); and Christopher Schirmer, Trusetal (DE)
Assigned to Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V., Munich (DE)
Filed by Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V., Munich (DE)
Filed on Feb. 21, 2020, as Appl. No. 16/797,877.
Application 16/797,877 is a continuation of application No. PCT/EP2017/071250, filed on Aug. 23, 2017.
Prior Publication US 2020/0191848 A1, Jun. 18, 2020
Int. Cl. G01R 27/28 (2006.01); G01R 29/10 (2006.01); H04B 17/12 (2015.01); H04B 7/0413 (2017.01)
CPC G01R 29/105 (2013.01) [H04B 7/0413 (2013.01); H04B 17/12 (2015.01)] 38 Claims
OG exemplary drawing
 
1. A method for wirelessly calibrating/testing a beamforming network of a multi-antenna receiver of a device under test, the method comprising:
wirelessly transmitting a first signaling information between the device under test and a device tester, the first signaling information indicating a calibration request, wherein the first signaling information is transmitted by the device under test or the device tester;
estimating, in response to the first signaling information, channel transfer function matrices between active antenna ports of the multi-antenna receiver of the device under test and antenna ports of the device tester using reference signals wirelessly transmitted from the device tester to the device under test, and transmitting the estimated channel transfer function matrices or an information derived therefrom from the device under test to the device tester;
wirelessly transmitting a second signaling information between the device under test and the device tester, the second signaling information indicating a precoded transmission request, wherein the second signaling information is transmitted by the device under test or the device tester; and
wirelessly transmitting, in response to the second signaling information, precoded reference signals from the device tester to the device under test using precoder matrices selected or determined based on the estimated channel transfer function matrices or the information derived therefrom, to acquire interference free channels between the device tester and the device under test allowing the reference signals to be received independently at each of the active antenna ports of the multi-antenna receiver of the device under test.