A 684Mbps 57mW joint QR decomposition and MIMO processor for 4×4 MIMO-OFDM systems

This paper presents a configurable MIMO detector with QR decomposition and channel interpolation for 4×4 MIMO-OFDM systems. QR decomposition (QRD) processor and MIMO detector are usually investigated independently in the literature; however, this methodology usually limits operating condition to only slow fading channel. Therefore, this study jointly designs a hardware architecture for QR decomposition and MIMO detection without interface memory buffer, and the channel interpolation is also performed at the same time. This QR-based MIMO detector is implemented in a 90nm CMOS process with 2.02mm² core area. The chip consumes 56.8mW at 114MHz operating frequency with 1.0V supply and achieves 684Mbps throughput. The proposed chip, which performs one QRD and one MIMO detection for one OFDM symbol, is the first MIMO detector in the literature that supports real-time QR decomposition and MIMO detection for fast fading MIMO-OFDM systems.