TY - JOUR
T1 - Simple Semi-Grant-Free Transmission Strategies Assisted by Non-Orthogonal Multiple Access
AU - Ding, Zhiguo
AU - Schober, Robert
AU - Fan, Pingzhi
AU - Vincent Poor, H.
N1 - Funding Information:
Manuscript received December 18, 2018; revised February 11, 2019; accepted March 1, 2019. Date of publication March 7, 2019; date of current version June 14, 2019. The work of Z. Ding was supported by the UK Engineering and Physical Sciences Research Council under grant number EP/P009719/2 and by H2020-MSCA-RISE-2015 under grant number 690750. The work of P. Fan was supported by the NSFC project No.61731017, NSFC-NRF project No.61661146003/NRF2016NRF-NSFC001-089, and the 111 Project No.111-2-14. The work of H. V. Poor was supported by the U.S. National Science Foundation under Grants CCF-093970 and CCF-1513915. The associate editor coordinating the review of this paper and approving it for publication was H. Zhang. (Corresponding author: Zhiguo Ding.) Z. Ding is with the Department of Electrical Engineering, Princeton University, Princeton, NJ 08544 USA, and also with the School of Electrical and Electronic Engineering, The University of Manchester, Manchester M13 9PL, U.K. (e-mail: [email protected]).
Publisher Copyright:
© 1972-2012 IEEE.
PY - 2019/6
Y1 - 2019/6
N2 - Grant-free transmission is an important feature to be supported by future wireless networks since it reduces the signaling overhead caused by conventional grant-based schemes. However, for grant-free transmission, the number of users admitted to the same channel is not capped, which can lead to a failure of multi-user detection. This paper proposes non-orthogonal multiple-access (NOMA) assisted semi-grant-free (SGF) transmission, which is a compromise between grant-free and grant-based schemes. In particular, instead of reserving channels either for grant-based users or grant-free users, the focus here is on an SGF communication scenario, where users are admitted to the same channel via a combination of grant-based and grant-free protocols. As a result, a channel reserved by a grant-based user can be shared by grant-free users, which improves both connectivity and spectral efficiency. Two NOMA assisted SGF contention control mechanisms are developed to ensure that, with a small amount of signaling overhead, the number of admitted grant-free users is carefully controlled and the interference from the grant-free users to the grant-based users is effectively suppressed. Analytical results are provided to demonstrate that the two proposed SGF mechanisms employing different successive interference cancelation decoding orders are applicable to different practical network scenarios.
AB - Grant-free transmission is an important feature to be supported by future wireless networks since it reduces the signaling overhead caused by conventional grant-based schemes. However, for grant-free transmission, the number of users admitted to the same channel is not capped, which can lead to a failure of multi-user detection. This paper proposes non-orthogonal multiple-access (NOMA) assisted semi-grant-free (SGF) transmission, which is a compromise between grant-free and grant-based schemes. In particular, instead of reserving channels either for grant-based users or grant-free users, the focus here is on an SGF communication scenario, where users are admitted to the same channel via a combination of grant-based and grant-free protocols. As a result, a channel reserved by a grant-based user can be shared by grant-free users, which improves both connectivity and spectral efficiency. Two NOMA assisted SGF contention control mechanisms are developed to ensure that, with a small amount of signaling overhead, the number of admitted grant-free users is carefully controlled and the interference from the grant-free users to the grant-based users is effectively suppressed. Analytical results are provided to demonstrate that the two proposed SGF mechanisms employing different successive interference cancelation decoding orders are applicable to different practical network scenarios.
KW - cognitive radio NOMA
KW - grant free transmission
KW - massive connectivity
KW - Non-orthogonal multiple access (NOMA)
UR - http://www.scopus.com/inward/record.url?scp=85067584894&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2019.2903443
DO - 10.1109/TCOMM.2019.2903443
M3 - Article
AN - SCOPUS:85067584894
SN - 0090-6778
VL - 67
SP - 4464
EP - 4478
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 6
M1 - 8662677
ER -