Novel energy-efficient scalable soft-output SSFE MIMO detector architectures

Energy-efficient scalable soft-output signal detectors are of significant interest in emerging multiple-input multiple-output (MIMO) wireless communication systems. However, traditional high-performance MIMO detectors consume a rather high amount of power, are typically constraint to one modulation scheme and are not scalable with the number of antennas. Hence, they are not well-suited for future energy-efficient software defined radio (SDR) platforms. This paper presents two energy-efficient scalable MIMO detector architectures: one optimized for high throughput, one for low area. Both architectures support 16-QAM as well as 64-QAM while offering soft-output and near-ML performance. The 2 times 2 high-throughput architecture was implemented in CMOS 65 nm technology and subsequently scaled to 4 times 4 and 8 times 8. The 4 times 4 instance provides up to 300 Mbps throughput while consuming only 0.3 mm² area and 28 mW power. The 8 times 8 instance offers a throughput 10times better than the state-of-the-art while consuming 2/3 less power. Thus, the proposed near-ML selective spanning with fast enumeration (SSFE) based detector architectures are not only multi-standard capable and scalable, they are also highly efficient.