Communications, Signal Processing and Learning

Works on coded modulation, space-time coding, and signal processing for wireless communication, including single- and double-symbol-decodable space-time block codes for MIMO systems. Related interests span cooperative communication, network coding, cognitive radio and spectrum sensing, and MIMO radar.

Works on wireless communications and networking, with emphasis on radio resource allocation and energy-efficient (green) cellular networks, device-to-device communication, and user association in heterogeneous wireless access networks. Related interests span the Internet of Things, visible-light communication, and machine-learning approaches to wireless positioning.

Works on the mathematical modelling, simulation, and prototyping of wireless systems and networks. Interests include interference management and coexistence, low-power and low-latency connectivity, network softwarization and security, the Internet of Things, and ICT for societal development, informed by industry experience developing Wi-Fi and Bluetooth system-on-chip technologies.

Works on communication theory, signal processing, and the design of wireless systems, with emphasis on network MIMO and standards-facing research for 5G and 6G. Contributions include the pi/2-BPSK waveform developed at IIT Hyderabad and subsequently adopted into 3GPP 5G specifications, with current work on 6G prototypes in the 7 GHz band, massive MIMO antenna arrays, OTFDM and structural MIMO waveforms, and non-terrestrial LEO/GEO systems.

Works in coding and information theory, centred on index coding — including index coding over noisy channels, index-coded modulation, and source coding for cache-aided receivers. Applications extend to vehicle-to-everything (V2X) communication and channel estimation for 6G systems.

Works on communication theory and signal processing for wireless systems and networks, spanning physical-layer modulation, synchronisation, and channel coding. Related interests include cooperative communication, heterogeneous network analysis, power allocation for LED-based optical wireless systems, and applications of AI and machine learning.

Works in coding and information theory with a focus on erasure codes for distributed storage — regenerating codes, the node-repair problem, and minimum-storage regenerating (MSR) constructions, including the coupled-layer Clay codes that brought MSR codes into practical storage systems. Further interests include low-latency streaming codes and privacy and security.

Works on physical-layer design for wireless communication, including OTFS modulation, integrated sensing and communication (ISAC) with MIMO-OTFS, intelligent reflecting surfaces, MIMO systems, and physical-layer security.

Worked on coding techniques for wireless communications, networks and storage. Past work includes lattice index coding, index coding with local decodability, codes for cache updates, coded data rebalancing, spatial modulation and space-time block codes. Recent work includes design of a new class of algebraic error correcting codes that achieve capacity in the erasure channel.

Current interest includes quantum error correction.

Studies combinatorial and algorithmic problems in Fourier analysis and their consequences for signal processing and machine learning. Topics include universal sampling sets for bandlimited signals and the associated uncertainty principles, characterisations of convolution idempotents, the Fuglede conjecture via association schemes, and how additive structure in the frequency support governs the computational complexity of the DFT, alongside convex and combinatorial optimisation.

Works on information theory and coding, with applications to data compression, statistical inference, and security. Recent research interests include data compression with locality and privacy, distributed estimation and learning, and model compression.

Leads the Speech Information Processing (SIP) Lab, working on the processing, analysis, and understanding of real speech — read, conversational, and emotional — recorded in natural environments. Topics include speech recognition and synthesis, speech enhancement, prosody modelling, speaker recognition for biometrics, language identification, voice conversion, and spoken-audio search, with emphasis on Indian languages.

Leads the Lab for Video and Image Analysis (LFOVIA), working on image and video quality assessment, perceptually optimal algorithm design, and machine learning. Recent work includes no-reference and completely blind quality assessment of user-generated video content and models informed by the visual cortex, with related interests in multimedia communication and biomedical imaging.

Works on multimedia signal processing and compression, network information theory, and multiterminal source coding, together with statistical modelling of complex data. Application areas include biomedical signal, image, and video analysis — notably in cardiology and ophthalmology — immersive and 3D multimedia processing, and neighbourhood-scale pollution mapping.

Works on cyber-physical systems and the Internet of Things, wireless sensor networks, embedded systems, and energy-efficient green communication. Leads research on autonomous navigation for both aerial and terrestrial platforms — including UAV and drone-based sensing, V2X communication, and living-lab testbeds — through the TiHAN technology innovation hub at IIT Hyderabad.

Works on wireless communications and the application of artificial intelligence and machine learning to wireless systems, including learning-based radio resource allocation and machine learning for 6G networks, connecting academic research with industry 5G and 6G product development.

Research spans wireless communication, cognitive radio, wireless sensor networks, and statistical signal processing, extending to cyber-physical systems, the Internet of Things, artificial intelligence, and digital fabrication. Author of several monographs and a large body of journal work across signal processing and communications.

Brings a policy and regulatory perspective to the department's communications research, drawing on a career in the Indian Telecommunication Service covering telecom policy implementation, project execution and enforcement, and international engagement at the Department of Telecommunications, including service as Secretary of the Telecom Regulatory Authority of India (TRAI).

Works on digital signal processing, speech and image processing, and artificial neural networks. Contributions developed over four decades include phase processing using group-delay functions, zero-frequency filtering for extracting excitation information from speech, zero-time windowing for vocal-tract characterisation, and single-frequency filtering for speech analysis at varying temporal and spectral resolutions.