58 citations · 164 across the 7 of their papers we have counts for
7 papers
Joint Phase-Time Arrays: A Paradigm for Frequency-Dependent Analog Beamforming in 6G
Vishnu V. Ratnam, Jianhua Mo, Ahmad AlAmmouri +4
Hybrid beamforming is an attractive solution to build cost-effective and energy-efficient transceivers for millimeter-wave and terahertz systems. However, conventional hybrid beamf…
Optimal preprocessing of WiFi CSI for sensing applications
Vishnu V. Ratnam, Hao Chen, Hao Hsuan Chang +3
Due to its ubiquitous and contact-free nature, the use of WiFi infrastructure for performing sensing tasks has tremendous potential. However, the channel state information (CSI) me…
Performance of Analog Beamforming Systems with Optimized Phase Noise Compensation
Vishnu V. Ratnam
Millimeter-wave and Terahertz frequencies, while promising high throughput and abundant spectrum, are highly susceptible to hardware non-idealities like phase-noise, which degrade…
Periodic Analog Channel Estimation Aided Beamforming for Massive MIMO Systems
Vishnu V. Ratnam, Andreas F. Molisch
Analog beamforming is an attractive and cost-effective solution to exploit the benefits of massive multiple-input-multiple-output systems, by requiring only one up/down-conversion…
Continuous Analog Channel Estimation Aided Beamforming for Massive MIMO Systems
Vishnu V. Ratnam, Andreas F. Molisch
Analog beamforming greatly reduces the implementation cost of massive antenna transceivers by using only one up/down-conversion chain. However, it incurs a large pilot overhead whe…
Hybrid Beamforming with Selection for Multi-user Massive MIMO Systems
Vishnu V. Ratnam, Andreas F. Molisch, Ozgun Y. Bursalioglu +1
This work studies a variant of hybrid beamforming, namely, hybrid beamforming with selection (HBwS), as an attractive solution to reduce the hardware cost of multi-user Massive Mul…
Hybrid Beamforming for Massive MIMO - A Survey
Andreas F. Molisch, Vishnu V. Ratnam, Shengqian Han +4
Hybrid multiple-antenna transceivers, which combine large-dimensional analog pre/postprocessing with lower-dimensional digital processing, are the most promising approach for reduc…