Abstract
The mobile WiMAX standard (802.16e) uses
multiple-input multiple-output (MIMO) limited feedback linear
precoding to exploit the channel state information at the
transmitter. Although the performance of limited feedback
linear precoding in relation to traditional open-loop MIMOOFDM
has been extensively studied in the literature, these
studies commonly assume perfect channel estimation at the
receiver. In a practical OFDM-based system, the estimated
channel matrix often differs from the actual channel matrix due
to errors incurred in the channel estimation process. This
results in degraded performance relative to the case with
perfect channel estimation. To date, few researchers have
studied the impact of channel estimation error on the
performance of an OFDM limited feedback linear precoding
system. This paper investigates the channel estimation error
using 1) an MMSE channel estimator that takes into account
the subcarrier correlation when estimating the channel, 2) a
Low Rank (LR) channel estimator that relaxes the requirement
for a perfect channel covariance matrix in the MMSE receiver,
and 3) a ZF estimator where this correlation information is
ignored. Simulation results show that with the MMSE
estimator the system suffers very little array gain loss with a
performance degradation of 0.2dB SNR. Compared to the
MMSE estimator, the LR estimator incurs a small performance
loss of around 0.5dB. Finally, when the ZF estimator is
implemented, a significant performance degradation
Translated title of the contribution | Mobile WiMAX: impact of channel estimation error on the performance of limited feedback linear precoding |
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Original language | English |
Title of host publication | IEEE 21st International Symposium on Personal, Indoor and Mobile Radio Communications 2010 (PIMRC 2010), Istanbul, Turkey |
Publisher | Institute of Electrical and Electronics Engineers (IEEE) |
Pages | 1065 - 1069 |
Number of pages | 5 |
ISBN (Print) | 9781424480159 |
Publication status | Published - 26 Sept 2010 |