Downlink channel covariance matrix (DCCM) estimation for FDD SDMA
Ying‐Chang Liang, Fion Wei Lin Chin, Alex Chichung Kot · 2002
The downlink channel covariance matrix (DCCM) is of vital importance in determining downlink beamforming weights for base station (BS) antenna array systems. For frequency-division-duplex (FDD) mode, DCCM is difficult to obtain due to lack of direct measurement of downlink channel responses. A novel technique is proposed for estimating DCCM using uplink channel responses only, which does not need DOA estimation and its association. The new technique is much simpler than the DOA-based approach and the GF algorithm.