  In multiple-input multiple-output communications, channel estimation is
paramount to keep base stations and users on track. This paper proposes a novel
PCA-based-principal component analysis-channel estimation approach for MIMO
orthogonal frequency division multiplexing systems. The channel frequency
response is firstly estimated with the least squares method, and then PCA is
used to filter only the higher singular components of the channel impulse
response, which is then converted back to the frequency domain. The proposed
approach is compared with the MMSE, the minimum mean square error estimation,
in terms of bit error rate versus Eb/N0.
