LMMSE Channel Estimation in OFDM Systems: A Vector Quantization Approach

The linear minimum mean square error (LMMSE) channel estimation yields the optimal performance in terms of the mean square error (MSE). However, the high computational complexity limits its application in practical systems. To overcome this issue, this letter proposes a vector quantization approach to the LMMSE channel estimation. The LMMSE filtering matrices corresponding to some typical wireless channels are calculated off-line. When performing the LMMSE channel estimation on-line, an appropriate LMMSE filtering matrix is selected according to the MSE criterion. At the expense of a negligible performance degradation, the computational complexity of the LMMSE channel estimation is reduced.