Title
Compressive Sensing Based User Activity Detection And Channel Estimation In Uplink Noma Systems
Abstract
Conventional request-grant based non-orthogonal multiple access (NOMA) incurs tremendous overhead and high latency. To enable grant-free access in NOMA systems, user activity detection (UAD) is essential. In this paper, we investigate compressive sensing (CS) aided UAD, by utilizing the property of quasi-time-invariant channel tap delays as the prior information. This does not require any prior knowledge of the number of active users like the previous approaches, and therefore is more practical. Two UAD algorithms are proposed, which are referred to as gradient based and time-invariant channel tap delays assisted CS (g-TIDCS) and mean value based and TIDCS (m-TIDCS), respectively. They achieve much higher UAD accuracy than the previous work at low signal-to-noise ratio (SNR). Based on the UAD results, we also propose a low-complexity CS based channel estimation scheme, which achieves higher accuracy than the previous channel estimation approaches.
Year
DOI
Venue
2020
10.1109/WCNC45663.2020.9120664
2020 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC)
Keywords
DocType
ISSN
NOMA, compressive sensing, user activity detection, channel estimation, multipath
Conference
1525-3511
Citations 
PageRank 
References 
0
0.34
0
Authors
6
Name
Order
Citations
PageRank
Yuanchen Wang112.38
Xu Zhu237147.63
Eng Gee Lim32220.78
Zhongxiang Wei43711.26
Liu Yujie512224.79
Yufei Jiang63222.37