mCore+: A Real-Time Design Achieving ∼ 500 μs Scheduling for 5G MU-MIMO Systems

Multi-User (MU)-MIMO technology plays a vital role in 5G NR. Under MU-MIMO transmission, multiple users can share the same time-frequency resources simultaneously. For 5G MU-MIMO systems, it is challenging to design a scheduler. The scheduler needs to determine resource block (RB) allocation, the number of data streams and modulation and coding scheme (MCS) for each user in each transmission time interval (TTI). In particular, multiple users can be co-scheduled on the same RB for MU-MIMO transmission. In addition, it is necessary for the scheduler to find a scheduling solution within each TTI to be useful. In this paper, we present mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq1-3207160.gif"/></alternatives></inline-formula>, a novel design and implementation that can achieve <inline-formula><tex-math notation="LaTeX">$\sim$</tex-math><alternatives><mml:math><mml:mo>∼</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq2-3207160.gif"/></alternatives></inline-formula>500 <inline-formula><tex-math notation="LaTeX">$\mu$</tex-math><alternatives><mml:math><mml:mi>μ</mml:mi></mml:math><inline-graphic xlink:href="chen-ieq3-3207160.gif"/></alternatives></inline-formula>s timing performance for 5G MU-MIMO systems. mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq4-3207160.gif"/></alternatives></inline-formula> is meticulously designed with a multi-phase optimization and heavily leverages large-scale parallel computation. In each phase, mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq5-3207160.gif"/></alternatives></inline-formula> either decomposes the optimization problem into a number of independent sub-problems, or reduces the search space into a smaller but most promising subspace, or both. mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq6-3207160.gif"/></alternatives></inline-formula> is validated on a commercial-off-the-shelf GPU platform. Experimental results show that mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq7-3207160.gif"/></alternatives></inline-formula> can offer a scheduling solution in <inline-formula><tex-math notation="LaTeX">$\sim$</tex-math><alternatives><mml:math><mml:mo>∼</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq8-3207160.gif"/></alternatives></inline-formula>500 <inline-formula><tex-math notation="LaTeX">$\mu$</tex-math><alternatives><mml:math><mml:mi>μ</mml:mi></mml:math><inline-graphic xlink:href="chen-ieq9-3207160.gif"/></alternatives></inline-formula>s for up to 100 RBs, 100 users, 29 MCS levels and <inline-formula><tex-math notation="LaTeX">$4 \times 12$</tex-math><alternatives><mml:math><mml:mrow><mml:mn>4</mml:mn><mml:mo>×</mml:mo><mml:mn>12</mml:mn></mml:mrow></mml:math><inline-graphic xlink:href="chen-ieq10-3207160.gif"/></alternatives></inline-formula> MIMO systems. Also, mCore<inline-formula><tex-math notation="LaTeX">$+$</tex-math><alternatives><mml:math><mml:mo>+</mml:mo></mml:math><inline-graphic xlink:href="chen-ieq11-3207160.gif"/></alternatives></inline-formula> can achieve better or comparable throughput performance compared to other state-of-the-art algorithms.