Title
Joint Activity Detection and Channel Estimation for IoT Networks: Phase Transition and Computation-Estimation Tradeoff.
Abstract
Massive device connectivity is a crucial communication challenge for Internet of Things (IoT) networks, which consist of a large number of devices with sporadic traffic. In each coherence block, the serving base station needs to identify the active devices and estimate their channel state information for effective communication. By exploiting the sparsity pattern of data transmission, we develop a structured group sparsity estimation method to simultaneously detect the active devices and estimate the corresponding channels. This method significantly reduces the signature sequence length while supporting massive IoT access. To determine the optimal signature sequence length, we study emph{the phase transition behavior} of the group sparsity estimation problem. Specifically, user activity can be successfully estimated with a high probability when the signature sequence length exceeds a threshold; otherwise, it fails with a high probability. The location and width of the phase transition region are characterized via the theory of conic integral geometry. We further develop a smoothing method to solve the high-dimensional structured estimation problem with a given limited time budget. This is achieved by sharply characterizing the convergence rate in terms of the smoothing parameter, signature sequence length and estimation accuracy, yielding a trade-off between the estimation accuracy and computational cost. Numerical results are provided to illustrate the accuracy of our theoretical results and the benefits of smoothing techniques.
Year
DOI
Venue
2018
10.1109/jiot.2018.2881486
IEEE Internet of Things Journal
Keywords
Field
DocType
Estimation,Channel estimation,Internet of Things,Smoothing methods,Geometry,Convergence,Computational efficiency
Base station,Mathematical optimization,Data transmission,Algorithm,Communication channel,Coherence (physics),Smoothing,Rate of convergence,Mathematics,Channel state information,Computation
Journal
Volume
Issue
ISSN
abs/1810.00720
4
2327-4662
Citations 
PageRank 
References 
3
0.36
36
Authors
4
Name
Order
Citations
PageRank
Tao Jiang121144.26
Yuanming Shi265953.58
Jun Zhang33772190.36
K. B. Letaief411078879.10