https://dspace.iiti.ac.in:8080/jspui/handle/123456789/14111 2026-08-15T10:03:22Z 2026-08-15T10:03:22Z Sukhsagar Bhatia, Vimal https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18894 2026-08-07T12:27:04Z 2026-01-01T00:00:00Z

Title: Energy-Efficient Hexagonal QAM for Fluid Antenna Systems: ASER Analysis under Imperfect CSI Authors: Sukhsagar; Bhatia, Vimal Abstract: Fluid antenna systems (FAS) have recently emerged as an effective solution for enhancing spatial diversity within compact and flexible wireless architectures. In practical communication systems, however, channel estimation errors are inevitable, which necessitates performance analysis under imperfect channel state information (CSI). This letter investigates the performance of an N-port FAS over Nakagami-m fading channels under imperfect CSI. Closed-form analytical expressions are derived for the cumulative distribution function, probability density function, outage probability, and ergodic capacity, along with high-SNR asymptotic approximations. The average symbol error rate of hexagonal QAM (HQAM) and rectangular QAM (RQAM) is also analyzed under the considered conditions. An asymptotic diversity study reveals that the achievable diversity order is jointly determined by the effective spatial rank of the FAS and the Nakagami fading parameter, while imperfect CSI degrades performance without affecting diversity scaling. Simulation results validate the analysis and demonstrate that HQAM outperforms conventional QAM, achieving approximately 2 dB and 0.8 dB SNR gains over 128-RQAM and 256-SQAM, respectively. © 2012 IEEE.

2026-01-01T00:00:00Z Lokhande, Mukul Sharma, Vijay P. Chand, S.V. Jaya Kumar, Sonu Vishvakarma, Santosh Kumar https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18637 2026-07-09T06:48:14Z 2026-01-01T00:00:00Z

Title: Trans-precision NPU for resource-efficient mobile AI acceleration Authors: Lokhande, Mukul; Sharma, Vijay P.; Chand, S.V. Jaya; Kumar, Sonu; Vishvakarma, Santosh Kumar Abstract: This paper introduces the Trans-precision NPU (T-NPU), a resource-efficient, multi-mode neural processing unit for mobile AI acceleration using a unified multi-precision datapath. At its core is a Single Instruction Multiple Data (SIMD) trans-precision multiply-accumulate unit (T-MAC) supporting heterogeneous formats, including FP4/FP8, INT4/INT8, and Posit-8/16, enabling flexible computation with improved throughput. The design uses a reconfigurable datapath that shares logic between exponent and mantissa processing to boost arithmetic intensity and energy efficiency. T-MAC integrates the DA-VINCI activation function to form a fundamental processing element for diverse workloads such as DNNs, Transformers, reinforcement learning, and generative AI. We evaluate an AXI-enabled unified core combining a systolic array and vector engine, integrated with a RISC-V CVA6 core and memory via the Cheshire framework. Results show a 14 pJ PDP, 2.4× better energy efficiency in 28 nm CMOS, and 1.8× fewer FPGA LUTs. MobileNet-SSD with KALAM-16 encoding shows ∼0.6% accuracy loss and 4.47 TOPS/W. © 2026 Elsevier B.V.

2026-01-01T00:00:00Z Mahapatra, Brahmadutta Yadav, Saurabh Chaudhary, Sumit Usha Mukjerjee, Shaibal https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18639 2026-07-09T06:48:14Z 2026-01-01T00:00:00Z

Title: Barrier Layer Optimization of DIBS-grown MgZnO/CdZnO Heterojunction for High Mobility Authors: Mahapatra, Brahmadutta; Yadav, Saurabh; Chaudhary, Sumit; Usha; Mukjerjee, Shaibal Abstract: This work explores the effect of Mg composition and growth environment of the MgZnO barrier layer in dual ion beam sputtering (DIBS) grown MgZnO/CdZnO heterostructure. Results suggest that a lower Mg composition of 5% provides higher mobility by reducing lattice mismatch and to form a well-defined heterojunction. Further, the presence of O2 during the growth environment reduces the carrier mobility (μ) of the two-dimensional electron gas, while increasing the carrier charge density (ns). The optimized heterojunction exhibited an increase in μ from 6.9 cm2/Vs to 28 cm2/Vs while the ns reduces from 3.22 × 1015 cm-2 to 4.22× 1013 cm-2. These findings are crucial for developing DIBS grown MgZnO/CdZnO high electron mobility transistors. © 2026 IEEE.

2026-01-01T00:00:00Z Singh, Abhishek https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18599 2026-07-09T06:48:13Z 2026-01-01T00:00:00Z

Title: Terahertz emission from interdigitated photoconductive antennas based on Ge-on-Si Authors: Singh, Abhishek Abstract: A large-area interdigitated photoconductive antenna (i-PCA) for terahertz (THz) emission with a novel metal-insulator-semiconductor interface is designed with the aim of developing compact and scalable THz devices. The photoconductive material is an amorphous germanium (Ge) film deposited using DC magnetron sputtering. The antenna electrodes are composed of gold-germanium (AuGe). With the integration of a silicon dioxide (SiO2) layer that acts as an electrical mask on alternate active areas, we present a simple approach to fabricate a large-area i-PCA. Along with a simplified fabrication compared to other existing designs, our approach increases the electrical robustness of the emitter and reduces the inactive gap area on the device. The i-PCA is capable of THz emission up to 2.5 THz and 36 dB signal-to-noise ratio, and is promising for applications in CMOS technologies. © 2026 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved. This article is available under the terms of the https://publishingsupport.iopscience.iop.org/iop-standard/v1.

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