OFDM with Index Modulation for Asynchronous mMTC Networks

Authors

Seda Doğan, Istanbul Medipol University
Armed Tusha, Istanbul Medipol University
Hüseyin Arslan, University of South FloridaFollow

Document Type

Article

Publication Date

2018

Keywords

asynchronous transmission, massive Machine-Type Communication (mMTC), Orthogonal Frequency Division Multiplexing (OFDM), OFDM with Index Modulation (OFDM-IM)

Digital Object Identifier (DOI)

https://doi.org/10.3390/s18041280

Abstract

One of the critical missions for next-generation wireless communication systems is to fulfill the high demand for massive Machine-Type Communications (mMTC). In mMTC systems, a sporadic transmission is performed between machine users and base station (BS). Lack of coordination between the users and BS in time destroys orthogonality between the subcarriers, and causes inter-carrier interference (ICI). Therefore, providing services to asynchronous massive machine users is a major challenge for Orthogonal Frequency Division Multiplexing (OFDM). In this study, OFDM with index modulation (OFDM-IM) is proposed as an eligible solution to alleviate ICI caused by asynchronous transmission in uncoordinated mMTC networks. In OFDM-IM, data transmission is performed not only by modulated subcarriers but also by the indices of active subcarriers. Unlike classical OFDM, fractional subcarrier activation leads to less ICI in OFDM-IM technology. A novel subcarrier mapping scheme (SMS) named as Inner Subcarrier Activation is proposed to further alleviate adjacent user interference in asynchronous OFDM-IM-based systems. ISA reduces inter-user interference since it gives more activation priority to inner subcarriers compared with the existing SMS-s. The superiority of the proposed SMS is shown through both theoretical analysis and computer-based simulations in comparison to existing mapping schemes for asynchronous systems.

Rights Information

This work is licensed under a Creative Commons Attribution 4.0 License.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Sensors, v. 18, issue 4, art. 1280

Scholar Commons Citation

Doğan, Seda; Tusha, Armed; and Arslan, Hüseyin, "OFDM with Index Modulation for Asynchronous mMTC Networks" (2018). Electrical Engineering Faculty Publications. 9.
https://digitalcommons.usf.edu/ege_facpub/9