An efficient FPGA implementation of QR decomposition using a novel systolic array architecture based on enhanced vectoring CORDIC

Abstract

Multiple input multiple output (MIMO) - Orthogonal frequency division multiplexing (OFDM) systems typically use Orthogonal-triangular (QR) decomposition. In this paper, we present a novel systolic array architecture to realize QR decomposition based on the Givens rotation method for a 4 × 4 real matrix. The coordinate rotation digital computer (CORDIC) algorithm is adopted and modified to speed up and simplify the Givens rotation. To verify the function and evaluate the performance, the proposed architectures are validated on a Virtex 5 FPGA development platform. Compared to a commercial implementation of vectoring CORDIC, an enhanced vectoring CORDIC is presented that uses 37.7% less hardware resources, dissipates 76.8% less power and provides a 1.8 times speed-up while maintaining the same computation accuracy. The novel QR systolic array architecture based on the enhanced vectoring CORDIC saves 5% in hardware and the throughput is improved by a factor of two with no accuracy penalty when compared with the best previous version of the QR systolic array.