Interpolation-Based QR Decomposition and Channel Estimation Processor for MIMO-OFDM System

This paper presents a modified interpolation-based QR decomposition algorithm for the grouped-ordering multiple input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Based on the original research that integrates the calculations of the frequency-domain channel estimation and the QR decomposition for the MIMO-OFDM system, this study proposes a modified algorithm that possesses a scalable property to save the power consumption for interpolation-based QR decomposition in the variable-rank MIMO scheme. Furthermore, we also develop the general equations and a timing scheduling method for the hardware design of the proposed QR decomposition processor for the higher-dimension MIMO system. Based on the pro posed algorithm, a configurable interpolation-based QR decomposition and channel estimation processor was designed and implemented using a 90-nm one-poly nine-metal CMOS technology. The processor supports 2 × 2, 2 × 4 and 4 × 4 QR-based MIMO detection for the 3GPP-LTE MIMO-OFDM system and achieves the throughput of 35.16 MQRD/s at its maximum clock rate 140.65 MHz.