Orthogonal time frequency space modulation (OTFS) has been proved to have better performance over orthogonal frequency division multiplexing (OFDM) under highmobility environments. In this manuscript, we address the challenging problem of channel estimation in high-mobility scenarios for 5G and beyond. To improve the spectral efficiency of the syst...
Recently, a frequency diverse array (FDA) has been employed in an orthogonal frequency division multiplexing (OFDM) transmitter to achieve secure wireless communication without mathematical encryption. However, an insecure coupling effect arises if the frequency increments are linearly assigned to all antenna elements. To solve this problem, random...
Published in Frontiers in Communications and Networks
In this study, a novel cluster index modulation (CIM) scheme, which is based on indexing the available clusters in the environment, is proposed for future mmWave communication systems. Exploiting the fact that the available clusters in the system are well separated in terms of their angular distribution, we selected the best path for each of them a...
Published in Frontiers in Communications and Networks
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 t...
Published in Frontiers in Communications and Networks
In this study, a mixed massive random access scheme is considered where part of users transmit both common information and user-specific information, while others transmit only common information. In this scheme, common information is transmitted by index modulation (IM)–aided unsourced random access (URA), while user-specific information is by IM-...
In this paper, we address a multiple-input multipleoutput (MIMO) communication system based on generalized spatial modulation (GSM) and dual-polarized (DP) antennas in sub-TeraHertz (sub-THz) bands to improve the Spectral Efficiency (SE) while reducing the spatial correlation effect and the space occupancy. Moreover, the joint Maximum Likelihood (M...
In this letter, we present filtered asymmetrically clipped optical-orthogonal frequency-division multiplexing with index modulation (FACO-OFDM-IM) for optical wireless systems. FACO-OFDM-IM optimizes the baseband bandwidth by filtering out-of-band spectral leakage caused by clipping. Additionally, IM enables FACO-OFDM-IM to impart granularity for s...
Published in Frontiers in Communications and Networks
Next generation wireless networks are expected to provide much higher data throughput and reliable connections for a far larger number of wireless service subscribers and machine-type nodes, which results in increasingly stringent requirements of spectral efficiency (SE) and energy efficiency (EE). Orthogonal frequency-division multiplexing with in...
Wireless Terabits per second (Tbps) link is needed for the new emerging data-hungry applications in Beyond 5G (B5G) (e.g., high capacity broadband, enhanced hotspot, three Dimensional (3D) extended reality, etc.). Besides, the sub-THz/THz bands are the next frontier for B5G due to scarce sub-GHz spectrum, and insufficient bandwidth for wireless Tbp...
