This letter proposes a novel time-asynchronous non-orthogonal multiple access (TA-NOMA) in downlink multicarrier systems. TA-NOMA applies an intentional time offset to control interference between multi-users and to improve spectral efficiency. We first propose a transceiver design for TA-NOMA, and analyze a novel type of interference caused by the intentional time offset. Based on the analysis, a singular value decomposition (SVD)-based pre-processing scheme is proposed. Numerical results show that the proposed TA-NOMA with pre-processing has a superior spectral efficiency compared with conventional power-domain NOMA. Another remarkable feature is that TA-NOMA does not require any user pairing.
Bibliographical noteFunding Information:
Manuscript received March 21, 2021; accepted April 15, 2021. Date of publication April 22, 2021; date of current version July 9, 2021. This work was supported in part by the National Research Foundation of Korea (NRF) Grant funded by the Korea Government (MSIT) under Grant 2018R1A2A1A05021029, and in part by Samsung Research in Samsung Electronics. The associate editor coordinating the review of this paper and approving it for publication was S. Zhang. (Corresponding author: Daesik Hong.) The authors are with the Information Telecommunication Laboratory, School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea (e-mail: email@example.com; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org). Digital Object Identifier 10.1109/LWC.2021.3074936
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All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Electrical and Electronic Engineering