Access Delay Constrained Activity Detection in Massive Random Access
Access Delay Constrained Activity Detection in Massive Random Access
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DOI：
10.1109/spawc51858.2021.9593173
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发表时间：
2021-09
期刊：
影响因子：
--
通讯作者：
Jyotish Robin;E. Erkip
中科院分区：
文献类型：
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作者：
Jyotish Robin;E. Erkip
在5G和下一代无线系统中，具有突发流量的大规模物联网网络预计将与蜂窝系统共存，以服务于几个延迟关键型应用。因此，重要的是接入点以最小的资源消耗迅速地识别活动设备，以实现大规模机器类型通信而不中断常规业务。本文提出了一种基于组测试的频率复用策略用于活动检测，该策略可以考虑网络延迟的约束，同时最小化整体资源利用率。其核心思想是在主动设备发现的每个时隙中，可以使用频域中的多个子载波并行地发起组测试以减少延迟。我们提出的方案是功能的渐近和非渐近制度的设备的总数（n）和并发激活设备的数量（k）。我们证明，渐近地，当可用时隙的数量缩放为${\Omega }\left（{\log \left（{\frac{n}{k}} \right）} \right）$，频率复用组测试策略需要$O\left（{k\log \left（{\frac{n}{k}} \right）} \right）$时频资源，这是阶最优的，并导致时间-频率资源的数量减少O（k）。槽相对于完全自适应广义二进制分裂的最优策略。此外，我们建立的频率复用GT策略显示出显着的宽容，估计误差在k。与3GPP标准化NB-IoT随机接入协议的比较表明，我们提出的策略在接入延迟和整体资源利用率方面的优势。
In 5G and future generation wireless systems, massive IoT networks with bursty traffic are expected to co-exist with cellular systems to serve several latency-critical applications. Thus, it is important for the access points to identify the active devices promptly with minimal resource consumption to enable massive machine-type communication without disrupting the conventional traffic. In this paper, a frequency-multiplexed strategy based on group testing is proposed for activity detection which can take into account the constraints on network latency while minimizing the overall resource utilization. The core idea is that during each time-slot of active device discovery, multiple subcarriers in frequency domain can be used to launch group tests in parallel to reduce delay. Our proposed scheme is functional in the asymptotic and non-asymptotic regime of the total number of devices (n) and the number of concurrently active devices (k). We prove that, asymptotically, when the number of available time-slots scale as ${\Omega }\left( {\log \left( {\frac{n}{k}} \right)} \right)$, the frequency-multiplexed group testing strategy requires $O\left( {k\log \left( {\frac{n}{k}} \right)} \right)$ time-frequency resources which is order-optimal and results in an O(k) reduction in the number of time-slots with respect to the optimal strategy of fully-adaptive generalized binary splitting. Furthermore, we establish that the frequency-multiplexed GT strategy shows significant tolerance to estimation errors in k. Comparison with 3GPP standardized random access protocol for NB-IoT indicates the superiority of our proposed strategy in terms of access delay and overall resource utilization.