The context for this book is to present a proficient channel estimation technique for performance improvement and complexity reduction of multiple antenna system. Matrix factorization is applied on LS estimation to reduce a full rank matrix into a simpler form in order to eliminate matrix inversion. Results indicate a significant improvement in SNR compared with LS estimation. The complexity comparison is performed in terms of mathematical operations, which shows that the approach outperforms LS estimation at a lower complexity and represents a good solution for channel estimation ...