School of Electrical Engineering, Korea University, Seoul 02841, Korea.
Department of Information and Communication Engineering, Dongguk University, Seoul 02841, Korea.
Sensors (Basel). 2021 Feb 12;21(4):1308. doi: 10.3390/s21041308.
The 3GPP standardized the physical layer specification in 5G New Radio to support enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) coexistence in usage scenarios including aerial vehicles (AVs). Dynamic multiplexing of URLLC traffic was standardized to increase the outage capacity. DM allocates a fully overlapped bandwidth part (BWP) of eMBB and URLLC AVs to perform the immediate scheduling of URLLC traffic by puncturing ongoing eMBB traffic. However, DM often suffers from a significant frame error incurred by puncturing. Meanwhile, BWP can be sliced orthogonally for eMBB and URLLC AVs, possibly preventing overdimensioning the resources depending on the eMBB and URLLC traffic loads. In this paper, we propose a dynamic BWP allocation scheme that switches between two multiplexing methods, dynamic multiplexing (DM) and orthogonal slicing (OS), so as to minimize an impact of uRLLC traffic on eMBB traffic. To implement efficient BWP allocation, the capacity region is analyzed by considering the effect of physical layer parameters, such as modulation and coding scheme (MCS) levels and code block group size on DM and OS. OS is effective for improving the eMBB throughput under a URLLC latency constraint for deterministic and predictable URLLC traffic, whereas DM has limited error-correcting capability against the URLLC's puncturing effect. The relative MCS level of eMBB and URLLC is critical in determining the eMBB traffic tolerance against puncturing. Identifying the performance tradeoff between DM and OS, the tolerance level is quantified by a URLLC load threshold. It is given in an approximate closed form, which is an essential reference for selecting DM over OS, enabling dynamic BWP allocation for the URLLC AV.
3GPP 标准化了 5G 新无线电的物理层规范，以支持增强型移动宽带 (eMBB) 和超可靠低延迟通信 (URLLC) 在包括飞行器 (AV) 在内的用例中的共存。为了增加中断容量，URLLC 流量的动态复用被标准化。DM 为 eMBB 和 URLLC AV 分配完全重叠的带宽部分 (BWP)，通过刺穿正在进行的 eMBB 流量来执行 URLLC 流量的即时调度。然而，DM 经常因刺穿而导致显著的帧错误。同时，BWP 可以为 eMBB 和 URLLC AV 进行正交切片，可能根据 eMBB 和 URLLC 流量负载防止资源过度设计。在本文中，我们提出了一种动态 BWP 分配方案，该方案在两种复用方法（动态复用 (DM) 和正交切片 (OS)）之间切换，以最大程度地减少 uRLLC 流量对 eMBB 流量的影响。为了实现有效的 BWP 分配，通过考虑物理层参数（例如调制和编码方案 (MCS) 级别和码字块大小）对 DM 和 OS 的影响来分析容量区域。在 URLLC 延迟约束下，对于确定性和可预测的 URLLC 流量，OS 对提高 eMBB 吞吐量是有效的，而 DM 对 URLLC 的穿孔效应具有有限的纠错能力。eMBB 和 URLLC 的相对 MCS 级别对于确定 eMBB 流量对穿孔的容忍度至关重要。确定 DM 和 OS 之间的性能权衡，通过 URLLC 负载阈值量化容忍度水平。它以近似闭式给出，这是选择 DM 而不是 OS 的重要参考，为 URLLC AV 动态分配 BWP 提供了依据。
