Characterization of an indoor MIMO channel in frequency domain using the 3D-SAGE algorithm

In this paper, the frequency domain (FD) SAGE (Space-Alternating Generalized Expectation-maximization) algorithm has been extended to the MIMO case in order to determine the angular and temporal channel characteristics at both ends; of the radio link. The implementation of the SAGE algorithm relies on the serial interference cancellation (SIC) technique which outperforms the conventional parallel interference cancellation (PIC) scheme when used in the frequency domain, especially in the common case of unequal power levels. The main purpose of our investigation has been twofold. Firstly, a synthetic environment was generated to testify the efficiency of the proposed algorithm in a severe multipath indoor scenario. Secondly, a measurement campaign was conducted and the obtained data were post-processed in order to assess the whole double-directional domain. The results revealed that the proposed algorithm demonstrates a stable performance and robustness as well as rapid convergence which are the principal criteria an estimation technique must fulfill.