Scalable interpolation-based QRD architecture for subcarrier-grouped-ordering MIMO-OFDM system

In the MIMO-OFDM system, QR-based MIMO detection suffers from high computational complexity of the QR decomposition due to the large numbers of antennas and subcarriers. Thus, interpolation-based QR decomposition was proposed to reduce the complexity. In this paper, we present a scalable interpolation-based QR decomposition algorithm for the grouped-ordering interpolation scheme. The proposed algorithm possesses computational stability because it eliminates the square root and division operations in the traditional Gram-Schmidt-based scheme. Besides, its scalability offers a power-saving structure for the lower-rank MIMO scheme in the future mobile communication systems. A hardware architecture is also developed to balance the hardware complexity and computation time. Finally, analysis result shows that the proposed algorithm reduces the complexity to 25.4%~61.3% of the traditional algorithm in the 4×4 MIMO-OFDM system.