In this paper, a calibration of fully-switched multiple-input multiple-output (MIMO) channel sounders with internal crosstalk is considered. The objective is to reduce the number of back-to-back (B2B) connections needed to estimate the transmitter (Tx) and receiver (Rx) response matrices that convey the information about linear distortion and internal crosstalk. For the B2B measurements, a signal and system model is developed using only a few pairs of the Tx and Rx ports of the sounder among all pairs of ports. Using the measurement model, a least-square estimation problem is then formulated and converted in the frequency domain into weighted rank-one approximation problems. Some exemplary sets of B2B connections are proposed for which fewer B2B connections are required than before. Given a proposed set of B2B connections, the alternate convex search (ACS) algorithm with a proper initialization is also proposed to solve the weighted rank-one approximation problems. Numerical results show that the ACS algorithm with the proposed initialization achieves a calibration performance only after a couple of iterations comparable to the conventional method that requires the B2B connections of all port pairs.
An Efficient Calibration of a Fully-Switched MIMO Channel Sounder with Internal Crosstalk
01.05.2020
202885 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch