Algorithm-architecture co-design of soft-output ML MIMO detector for parallel application specific instruction set processors

Abstract

Emerging SDR baseband platforms are usually based on multiple DLP+ILP processors with massive parallelism [10]. Although these platforms would theoretically enable advanced SDR signal processing, existing work implemented basic systems and simple algorithms. Importantly, MIMO is not fully supported in most implementations [7][9][11]. [1] implemented MIMO but with a simple linear detector. Our work explores the feasibility for SDR implementations of soft-output ML MIMO detectors, which brings 6--12 dB SNR gains when compared to popular linear detectors. Although soft-output ML MIMO detectors are considered to be challenging even for ASICs [3][4], we combine architecture-friendly algorithms, application specific instructions, code transformations and ILP/DLP explorations to make SDR implementations feasible. In our work, a 2x4 ADRES based ASIP with 16-way SIMD can deliver 193Mbps for 2x2 64QAM, and 368Mbps for 2x2 16QAM transmissions. To the best of our knowledge, this is the first work exploring SDR based soft-output ML MIMO detectors.