Implementation of LS, MMSE and SAGE channel estimators for mobile MIMO-OFDM

Author

Ketonen, Johanna ; Juntti, Markku ; Ylioinas, Juha ; Cavallaro, J.R.

Author_Institution

Centre for Wireless Commun., Univ. of Oulu, Oulu, Finland

fYear

2012

fDate

4-7 Nov. 2012

Firstpage

1092

Lastpage

1096

Abstract

The use of decision directed (DD) channel estimation in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) downlink receiver is studied in this paper. The 3GPP long term evolution (LTE) based pilot structure is used as a benchmark. The space-alternating generalized expectation-maximization (SAGE) algorithm is used to improve the performance from that of the pilot symbol based least-squares (LS) channel estimator. The DD channel estimation improves the performance with high user velocities, where the pilot symbol density is not sufficient. It can also be used to reduce the pilot overhead without any performance degradation. Minimum mean square error (MMSE) filtering can also be used in estimating the channel in between pilot symbols. The pilot based LS, MMSE and the SAGE channel estimators are implemented and the performance-complexity trade-offs are studied.

Keywords

3G mobile communication; Long Term Evolution; MIMO communication; OFDM modulation; channel estimation; computational complexity; expectation-maximisation algorithm; least mean squares methods; radio links; radio receivers; wireless channels; 3GPP long term evolution-based pilot structure; DD channel estimation; LTE-based pilot structure; MIMO OFDM downlink receiver; MMSE channel estimators; MMSE filtering; SAGE channel estimators; decision directed orthogonal; minimum mean square error filtering; mobile MIMO-OFDM; multiple-input multiple-output orthogonal frequency division multiplexing downlink receiver; performance-complexity trade-offs; pilot symbol density; pilot symbol-based LS channel estimator; pilot symbol-based least squares channel estimator; space-alternating generalized expectation-maximization algorithm; user velocities;

fLanguage

English

Publisher

ieee

Conference_Titel

Signals, Systems and Computers (ASILOMAR), 2012 Conference Record of the Forty Sixth Asilomar Conference on

Conference_Location

Pacific Grove, CA

ISSN

1058-6393

Print_ISBN

978-1-4673-5050-1

Type

conf

DOI

10.1109/ACSSC.2012.6489188

Filename

6489188