Optimal transmit strategies in MIMO Ricean channels with MMSE receiver

Author

Jorswieck, E.A. ; Sezgin, A. ; Boche, H. ; Costa, E.

Author_Institution

Fraunhofer-Inst. for Telecommun., Heinrich-Hertz-Inst., Berlin, Germany

Volume

5

fYear

2004

fDate

26-29 Sept. 2004

Firstpage

3787

Abstract

We study a MIMO system with MMSE receiver in a flat-fading environment. We assume that the receiver has perfect CSI and the transmitter knows only the mean channel matrix, either by feedback or channel estimation. First, we derive the properties of the average normalized MSE and its dependence on the singular values of the mean component. Next, we show that the optimal transmit strategy is to transmit in the direction of the eigenvectors of the squared mean component. In addition to this, we characterize the optimal power allocation using the necessary and sufficient optimality conditions. Furthermore, the optimal strategy for small SNR values is to perform beamforming, i.e., to transmit only in direction of the largest mean matrix eigenvalue.

Keywords

MIMO systems; Rician channels; channel estimation; eigenvalues and eigenfunctions; least mean squares methods; matrix algebra; radio receivers; MIMO Ricean channels; MIMO Rician channels; MMSE receiver; SNR; beamforming; channel estimation; channel state information; eigenvectors; feedback; flat-fading channels; matrix eigenvalue; mean channel matrix; normalized MSE; perfect CSI; power allocation; singular values; transmit strategies; Channel estimation; Covariance matrix; Eigenvalues and eigenfunctions; Estimation error; Fading; Intelligent networks; MIMO; Measurement; Rayleigh channels; Transmitters;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th

ISSN

1090-3038

Print_ISBN

0-7803-8521-7

Type

conf

DOI

10.1109/VETECF.2004.1404774

Filename

1404774