Reduced-complexity interpolation-based QR decomposition using partial layer mapping

This paper presents a double one-dimension interpolation-based QR decomposition (DOD-IQRD) algorithm and a partial layer-mapping (PLM) scheme for multiple-input multiple-output (MIMO) orthogonal-frequency-division-multiplexing (OFDM) systems. The proposed algorithm integrates the calculations of frequency-domain channel estimation and QR decomposition for MIMO-OFDM systems, and thus requires less computational complexity than traditional scheme. Besides, the proposed partial layer-mapping scheme can further reduce computational complexity with negligible performance degradation. The analysis results show that the double one-dimension interpolation-based QR decomposition algorithm reduces the complexity to 45.2% of the traditional algorithm in the 3GPP-LTE 4×4 MIMO-OFDM system. The proposed QR decomposition algorithm combined with the partial layer-mapping scheme can further save up to 70.5% computational complexity for MIMO-OFDM systems.