Quantum Annealing (QA)-accelerated MIMO detection is an emerging research approach in the context of NextG wireless networks. The opportunity is to enable large MIMO systems and thus improve wireless performance. The approach aims to leverage QA to expedite the computation required for theoretically optimal but computationally-demanding Maximum Likelihood detection to overcome the limitations of the currently deployed linear detectors. This paper presents X-ResQ, a QA-based MIMO detector system featuring fine-grained quantum task parallelism that is uniquely enabled by the Reverse Annealing (RA) protocol. Unlike prior designs, X-ResQ has many desirable system properties for a parallel QA detector and has effectively improved detection performance as more qubits are assigned. In our evaluations on a state-of-the-art quantum annealer, fully parallel X-ResQ achieves near-optimal throughput (over 10 bits/s/Hz) for $4\times6$ MIMO with 16-QAM using six levels of parallelism with 240 qubits and $220~\mu$s QA compute time, achieving 2.5--5$\times$ gains compared against other tested detectors. For more comprehensive evaluations, we implement and evaluate X-ResQ in the non-quantum digital setting. This non-quantum X-ResQ demonstration showcases the potential to realize ultra-large $1024\times1024$ MIMO, significantly outperforming other MIMO detectors, including the state-of-the-art RA detector classically implemented in the same way.

翻译：量子退火加速MIMO检测是下一代无线网络背景下新兴的研究方向，其机遇在于支持大规模MIMO系统以提升无线性能。该方法旨在利用量子退火加速理论上最优但计算量极大的最大似然检测所需的计算，从而克服当前线性检测器的局限性。本文提出X-ResQ——一种基于量子退火的MIMO检测器系统，其独特之处在于通过反向退火协议实现了细粒度量子任务并行性。与先前设计不同，X-ResQ在并行量子检测器中具备多项理想系统特性，且随着更多量子比特的分配，检测性能显著提升。在最新量子退火器上的评估表明，全并行X-ResQ在$4\times6$ MIMO、16-QAM配置下，采用六级并行（使用240个量子比特，量子退火计算时间为$220~\mu$s）实现了近最优吞吐量（超过10 bits/s/Hz），相比其他测试检测器获得2.5–5倍的增益。为进行更全面的评估，我们在非量子数字环境中实现了X-ResQ并测试其性能。该非量子X-ResQ演示展现了实现超大规模$1024\times1024$ MIMO的潜力，其性能显著优于其他MIMO检测器，包括以相同方式经典实现的先进反向退火检测器。