265 research outputs found
Multidimensional Index Modulation for 5G and Beyond Wireless Networks
This study examines the flexible utilization of existing IM techniques in a
comprehensive manner to satisfy the challenging and diverse requirements of 5G
and beyond services. After spatial modulation (SM), which transmits information
bits through antenna indices, application of IM to orthogonal frequency
division multiplexing (OFDM) subcarriers has opened the door for the extension
of IM into different dimensions, such as radio frequency (RF) mirrors, time
slots, codes, and dispersion matrices. Recent studies have introduced the
concept of multidimensional IM by various combinations of one-dimensional IM
techniques to provide higher spectral efficiency (SE) and better bit error rate
(BER) performance at the expense of higher transmitter (Tx) and receiver (Rx)
complexity. Despite the ongoing research on the design of new IM techniques and
their implementation challenges, proper use of the available IM techniques to
address different requirements of 5G and beyond networks is an open research
area in the literature. For this reason, we first provide the dimensional-based
categorization of available IM domains and review the existing IM types
regarding this categorization. Then, we develop a framework that investigates
the efficient utilization of these techniques and establishes a link between
the IM schemes and 5G services, namely enhanced mobile broadband (eMBB),
massive machine-type communications (mMTC), and ultra-reliable low-latency
communication (URLLC). Additionally, this work defines key performance
indicators (KPIs) to quantify the advantages and disadvantages of IM techniques
in time, frequency, space, and code dimensions. Finally, future recommendations
are given regarding the design of flexible IM-based communication systems for
5G and beyond wireless networks.Comment: This work has been submitted to Proceedings of the IEEE for possible
publicatio
Index and Composition Modulation
In this paper, we propose a novel modulation concept which we call
\emph{index and composition modulation (ICM)}. In the proposed concept, we use
indices of active/deactive codeword elements and compositions of an integer to
encode information. In this regard, we first determine the activated codeword
elements, then we exploit energy levels of these elements to identify the
compositions. We depict a practical scheme for using ICM with orthogonal
frequency division multiplexing (OFDM) and show that OFDM with ICM (OFDM-ICM)
can enhance the spectral efficiency (SE) and error performance of OFDM-IM. We
design an efficient low-complexity detector for the proposed technique.
Moreover, we analyze the error and SE performance of the OFDM-ICM technique and
show that it is capable of outperforming existing OFDM benchmarks in terms of
error and SE performance.Comment: 5 pages, 4 figures. arXiv admin note: text overlap with
arXiv:2006.1440
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