Abhishek Kumar

• Kumar, Abhishek; Martinez-Bauset, Jorge; Li, Frank Yong; Florea, Carmen & Dobre, Octavia A. (2023). Understanding Inter- and Intra-Cluster Concurrent Transmissions for IoT Uplink Traffic in MIMO-NOMA Networks: A DTMC Analysis. IEEE Internet of Things Journal. ISSN 2327-4662. 11(8), s. 14328–14343. doi: 10.1109/JIOT.2023.3341613.
• Kumar, Abhishek; Li, Frank Yong & Martinez-Bauset, Jorge (2023). Performance Evaluation of Cluster-based Concurrent Uplink Transmissions in MIMO-NOMA Networks , 2023 IEEE International Conference on Communications (ICC): Mobile and Wireless Networks Symposium. IEEE conference proceedings. ISSN 978-1-5386-7462-8. s. 1042–1047. doi: 10.1109/ICC45041.2023.10279821. Vis sammendrag

  To obtain benefits for non-orthogonal multiple access (NOMA) based concurrent transmissions for uplink Internet of things (IoT) traffic in multi-antenna enabled networks, device clustering has been a challenging task. Most previous studies focused on grouping devices into clusters that are served by different beams in multiple input multiple output (MIMO)-NOMA networks. In this paper, we perform an exploratory study on the impact of both intra- and inter-cluster interference on the performance of uplink concurrent transmissions considering that multiple clusters are served by a single beam. For performance assessment, we define two metrics, cluster throughput and transmission latency, and evaluate network performance with various network configurations. The study provides insight on how to configure device clusters and perform access control in order to maximize performance and improve fairness. As devices closer to the base station experience less path attenuation, we introduce distinct access control mechanisms to improve transmissions fairness for concurrent transmissions from difference clusters.

• Kumar, Abhishek; Li, Frank Yong & Martinez-Bauset, Jorge (2022). Revealing the Benefits of Rate-Splitting Multiple Access for Uplink IoT Traffic. IEEE Global Communications Conference (GLOBECOM). ISSN 2334-0983. doi: 10.1109/GLOBECOM48099.2022.10000752. Vis sammendrag

  To address the challenges faced by non-orthogonal multiple access (NOMA) for multiple access in beyond fifth gen-eration (B5G) networks, rate-splitting multiple access (RSMA) has newly emerged as a promising approach. In addition to achieving high data rates, RSMA may be used for massive machine-type communication (mMTC)/massive Internet of things (mIoT) applications as well. Although RSMA addresses the user coupling and scheduling overhead problems met by NOMA, it is not clear whether and how RSMA can be applied to uplink mMTC/mIoT traffic. In this study, we explore the applicability of RSMA for uplink traffic and investigate whether there is any benefit to employ RSMA and if yes how this benefit can be achieved. To this end, we propose a novel uplink RSMA scheme with two constituent components, known as inter-device decoding and intra -device decoding, respectively. Through user pairing for inter-device decoding and power allocation for intra-device decoding, we reveal under which circumstances RSMA can bring benefits for uplink traffic.

• Kumar, Abhishek & Dash, Soumya P. (2022). Optimal Multi-Level Amplitude-Shift Keying Modulation for a Reliable Channel Magnitude Detection-Based Receive Diversity Powerline Communication System. IEEE Transactions on Green Communications and Networking (ITGCN). 6(4), s. 2168–2178. doi: 10.1109/TGCN.2022.3172786. Vis sammendrag

  The implementation of a coherent powerline communication (PLC) receiver increases its hardware complexity and energy consumption, which can be tackled by a non-coherent receiver. However, this reduces the reliability of the PLC systems. To meet this trade-off, a novel energy-efficient receiver structure is proposed in this study that exploits the knowledge of the channel magnitude of a receive diversity PLC system. The transmitter employs multi-level amplitude-shift keying (ASK) modulation for data transmission via the PLC channels subjected to Rayleigh multipath phenomenon and corrupted by additive Nakagami-m background noise, which would lead to a superior performance as compared to other modulation schemes owing to the channel magnitude-based proposed receiver. Utilizing the receiver structure, closed-form expression for symbol error probability (SEP) and its asymptotic expression at a high average signal-to-noise ratio (SNR) are derived using a characteristic function approach. Furthermore, to achieve the simultaneous design of an energy-efficient modulation scheme and a reliable PLC system, optimal ASK signaling levels are obtained with a constraint on the total available energy at the transmitter end. The analytical relation of the derived optimal multi-level ASK constellation with the traditional ASK constellation is obtained at high SNR values. The proposed channel magnitude-based receiver is found to achieve full diversity order and numerical results presented provide various insights towards the design of the energy-efficient PLC system.

• Afshar, Mehran; Patel, Hitendra R.H.; Jain, Ankit; Kumar, Abhishek; Patel, Prashant & James, Nicholas D. [Vis alle 7 forfattere av denne artikkelen] (2019). Chronic tyrosine kinase inhibitor (TKI) use in metastatic renal cell carcinoma (mRCC): can this lead to the adverse effect of hypogonadism? Expert Review of Anticancer Therapy. ISSN 1473-7140. 19(6), s. 529–532. doi: 10.1080/14737140.2019.1609355.
• Kumar, Abhishek; Priyadarshi, Anish; Shukla, Sudhanshu; Manjappa, Manukumara; Haur, Lew Jia & Mhaisalkar, Subodh G. [Vis alle 7 forfattere av denne artikkelen] (2018). Ultrafast THz photophysics of solvent engineered triple-cation halide perovskites. Journal of Applied Physics. ISSN 0021-8979. 124:215106(21), s. 1–5. doi: 10.1063/1.5051561.
• Ananthanarayanan, Divya; Wong, Johnson; Ho, Jian Wei; Kumar, Abhishek; Lee, Rainer & Haug, Halvard [Vis alle 7 forfattere av denne artikkelen] (2018). Evaluation of diffused phosphorus emitters using Griddler-PC1D , Proceedings of 7th World Conference on Photovoltaic Energy Conversion (WCPEC-7) 2018. IEEE conference proceedings. ISSN 978-1-5386-8529-7. s. 2651–2654. doi: 10.1109/pvsc.2018.8547617.

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