activity
20142025
most citedSuperimposed Pilots are Superior for Mitigating Pilot Contamination in Massive MIMO

102 citations · 165 across the 12 of their papers we have counts for

collaborators

13 papers

cs.NI2025

Knowledge Graph-Based approach for Sustainable 6G End-to-End System Design

Akshay Jain, Sylvaine Kerboeuf, Sokratis Barmpounakis +17

Previous generations of cellular communication, such as 5G, have been designed with the objective of improving key performance indicators (KPIs) such as throughput, latency, etc. H…

eess.SP2024

Downlink Power Control based UE-Sided Initial Access for Tactical 5G NR

Akshay Jain, Karthik Upadhya, Mikko A. Uusitalo +1

Communication technologies play a crucial role in battlefields. They are an inalienable part of any tactical response, whether at the battlefront or inland. Such scenarios require…

eess.SP2024

LPD-Aware Uplink CSI-based 5G NR Downlink Synchronization for Tactical Networks

Karthik Upadhya, Akshay Jain, Mikko A. Uusitalo +1

5G NR is touted to be an attractive candidate for tactical networks owing to its versatility, scalability, and low cost. However, tactical networks need to be stealthy, where an ad…

cs.IT2023

Heterogeneous Rank Beamforming for Industrial Communications

Andrea Bedin, Akshay Jain, Andrea Zanella +1

This paper proposes a novel hardware beamforming architecture, which is capable of utilizing a different number of Radio Frequency (RF) chains in different parts of the bandwidth.…

cs.NI2023

28 GHz NLOS Channel Measurements Revealing Low Path Loss and High Angular Spread in Container Ports

Andrea Bedin, Dmitry Chizhik, Jinfeng Du +4

This paper presents results from a comprehensive measurement campaign conducted at 28 GHz inside a container canyon within a commercial port environment. The measurements are perfo…

cs.CY2022

Digital Twins for Industry 4.0 in the 6G Era

Bin Han, Mohammad Asif Habibi, Bjoern Richerzhagen +10

Having the Fifth Generation (5G) mobile communication system recently rolled out in many countries, the wireless community is now setting its eyes on the next era of Sixth Generati…

eess.SP2022

Jamming Resilient Indoor Factory Deployments: Design and Performance Evaluation

Leonardo Chiarello, Paolo Baracca, Karthik Upadhya +3

In the framework of 5G-and-beyond Industry 4.0, jamming attacks for denial of service are a rising threat which can severely compromise the system performance. Therefore, in this p…

eess.SP2021

Jamming Detection With Subcarrier Blanking for 5G and Beyond in Industry 4.0 Scenarios

Leonardo Chiarello, Paolo Baracca, Karthik Upadhya +2

Security attacks at the physical layer, in the form of radio jamming for denial of service, are an increasing threat in the Industry 4.0 scenarios. In this paper, we consider the p…

cs.IT2019★ 1 cited

On the Spectral Efficiency for Massive MIMO Systems With Imperfect Spacial Covariance Information

A. K. Kocharlakota, K. Upadhya, S. A. Vorobyov

This paper studies the impact of imperfect channel covariance information on the uplink (UL) and downlink (DL) spectral efficiencies (SEs) of a time-division duplexed (TDD) massive…

cs.IT2018★ 61 cited

Covariance Matrix Estimation for Massive MIMO

Karthik Upadhya, Sergiy A. Vorobyov

We propose a novel pilot structure for covariance matrix estimation in massive multiple-input multiple-output (MIMO) systems in which each user transmits two pilot sequences, with…

cs.IT2016

Downlink Performance of Superimposed Pilots in Massive MIMO systems

Karthik Upadhya, Sergiy A. Vorobyov, Mikko Vehkapera

In this paper, we investigate the downlink throughput performance of a massive multiple-input multiple-output (MIMO) system that employs superimposed pilots for channel estimation.…

cs.IT2016★ 102 cited

Superimposed Pilots are Superior for Mitigating Pilot Contamination in Massive MIMO

Karthik Upadhya, Sergiy A. Vorobyov, Mikko Vehkapera

In this paper, superimposed pilots are introduced as an alternative to time-multiplexed pilot and data symbols for mitigating pilot contamination in massive multiple-input multiple…

cs.IT2014★ 1 cited

A Risk Minimization Framework for Channel Estimation in OFDM Systems

Karthik Upadhya, Chandra Sekhar Seelamantula, K. V. S. Hari

We address the problem of channel estimation for cyclic-prefix (CP) Orthogonal Frequency Division Multiplexing (OFDM) systems. We model the channel as a vector of unknown determini…