Next Article in Journal
YOT-Net: YOLOv3 Combined Triplet Loss Network for Copper Elbow Surface Defect Detection
Previous Article in Journal
Combining Indoor Positioning Using Wi-Fi Round Trip Time with Dust Measurement in the Field of Occupational Health
 
 
Article

Null Subcarrier Index Modulation in OFDM Systems for 6G and Beyond

by 1 and 2,*
1
Department of Electrical and Electronics Engineering, Istanbul University-Cerrahpasa, Istanbul 34320, Turkey
2
Department of Electrical and Electronics Engineering, Izmir University of Economics, Izmir 35330, Turkey
*
Author to whom correspondence should be addressed.
Academic Editor: Dimitrie C. Popescu
Sensors 2021, 21(21), 7263; https://doi.org/10.3390/s21217263
Received: 8 September 2021 / Revised: 12 October 2021 / Accepted: 13 October 2021 / Published: 31 October 2021
(This article belongs to the Special Issue Flexible Radio Access Techniques for 5G and Beyond)
Computational complexity is one of the drawbacks of orthogonal frequency division multiplexing (OFDM)-index modulation (IM) systems. In this study, a novel IM technique is proposed for OFDM systems by considering the null subcarrier locations (NSC-OFDM-IM) within a predetermined group in the frequency domain. So far, a variety of index modulation techniques have been proposed for OFDM systems. However, they are almost always based on modulating the active subcarrier indices. We propose a novel index modulation technique by employing the part of the transmitted bit group into the null subcarrier location index within the predefined size of the subgroup. The novelty comes from modulating null subcarriers rather than actives and reducing the computational complexity of the index selection and index detection algorithms at the transmitter and receiver, respectively. The proposed method is physically straightforward and easy to implement owing to the size of the subgroups, which is defined as a power of two. Based on the results of our simulations, it appeared that the proposed NSC-OFDM-IM does not suffer from any performance degradation compared to the existing OFDM-IM, while achieving better bit error rate (BER) performance and improved spectral efficiency (SE) compared to conventional OFDM. Moreover, in terms of computational complexity, the proposed approach has a significantly reduced complexity over the traditional OFDM-IM scheme. View Full-Text
Keywords: OFDM; index modulation; null subcarrier; computational complexity; 6G and beyond OFDM; index modulation; null subcarrier; computational complexity; 6G and beyond
Show Figures

Figure 1

MDPI and ACS Style

Eren, T.; Akan, A. Null Subcarrier Index Modulation in OFDM Systems for 6G and Beyond. Sensors 2021, 21, 7263. https://doi.org/10.3390/s21217263

AMA Style

Eren T, Akan A. Null Subcarrier Index Modulation in OFDM Systems for 6G and Beyond. Sensors. 2021; 21(21):7263. https://doi.org/10.3390/s21217263

Chicago/Turabian Style

Eren, Tuncay, and Aydin Akan. 2021. "Null Subcarrier Index Modulation in OFDM Systems for 6G and Beyond" Sensors 21, no. 21: 7263. https://doi.org/10.3390/s21217263

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop