论文标题
一种有效的算法，用于在异步IoT系统中用于设备检测和通道估计
An Efficient Algorithm for Device Detection and Channel Estimation in Asynchronous IoT Systems
论文作者
论文摘要
最近，大量努力致力于大规模的机器型通信中的联合装置活动检测和通道估计问题。本文针对以前尚未解决的两个实用问题的针对性问题：在具有大量设备数量的系统中实时实现的非协同用户的异步传输和有效的算法。具体而言，本文考虑了一个实用的系统，其中每个活动设备发送的序言由于缺乏协调而被一些未知数的符号延迟。我们设法提出了检测主动设备并将其延迟和渠道估算为组套索问题的问题。然后，提出了一个块坐标下降算法，以在全球范围内解决此问题，在更新每个变量块时，可以使用其他变量块，这是我们感兴趣的问题的特殊结构。我们的分析表明，所提出的算法的总体复杂性很低，因此适用于实时应用。
A great amount of endeavour has recently been devoted to the joint device activity detection and channel estimation problem in massive machine-type communications. This paper targets at two practical issues along this line that have not been addressed before: asynchronous transmission from uncoordinated users and efficient algorithms for real-time implementation in systems with a massive number of devices. Specifically, this paper considers a practical system where the preamble sent by each active device is delayed by some unknown number of symbols due to the lack of coordination. We manage to cast the problem of detecting the active devices and estimating their delay and channels into a group LASSO problem. Then, a block coordinate descent algorithm is proposed to solve this problem globally, where the closed-form solution is available when updating each block of variables with the other blocks of variables being fixed, thanks to the special structure of our interested problem. Our analysis shows that the overall complexity of the proposed algorithm is low, making it suitable for real-time application.
