Givens rotation‐based QR decomposition for MIMO systems

Abstract

QR decomposition is an essential operation in various detection algorithms utilised in multiple-input multiple-output (MIMO) wireless communication systems. This study presents a Givens rotation-based QR decomposition for 4 × 4 MIMO systems. Instead of performing QR decomposition by coordinate rotation digital computer (CORDIC) algorithms, LUT compression algorithms are employed to rapidly evaluate the trigonometric functions. The proposed approach also provides greater accuracy compared with the CORDIC algorithms. QR decomposition is performed by complex Givens rotations cascaded with real Givens rotations. In complex Givens rotations, a modified triangular systolic array is adopted to reduce the delay units of the design and hence, reducing the hardware complexity. The proposed QR decomposition algorithm is implemented in TSMC 90 nm CMOS technology. It achieves the throughput of 53.5 million QR decompositions per second when operating at 214 MHz.