10 citations · 12 across the 18 of their papers we have counts for
21 papers
Low-complexity Equalization of Zak-OTFS Via Neumann Series
Vineetha Yogesh, Saif Khan Mohammed, Sandesh Rao Mattu +2
We describe a general method for selecting an orthonormal basis of carrier waveforms that aligns the basis with delay / Doppler characteristics of a wireless channel. We show that…
Modulation Augmentation and Constellation Shaping for LDPC-Coded QPSK
Heping Wan, Joonyoung Cho, Sandesh Rao Mattu +4
While constellation shaping improves spectral efficiency, its application to quadrature phase-shift keying (QPSK) remains limited. We address this limitation by incorporating a sho…
Real-Time and Scalable Zak-OTFS Receiver Processing on GPUs
Junyao Zheng, Chung-Hsuan Tung, Yuncheng Yao +6
Orthogonal time frequency space (OTFS) modulation offers superior robustness to high-mobility channels compared to conventional orthogonal frequency-division multiplexing (OFDM) wa…
Zak-OTFS: A Predictable Physical Layer for Communications and Sensing
Sandesh Rao Mattu, Nishant Mehrotra, Venkatesh Khammammetti +1
This tutorial derives the mathematical foundations of what it means for a carrier waveform to be predictable and non-selective. We focus on Zak-OTFS, where each carrier waveform is…
Delay-Doppler Channel Estimation using Arbitrarily Modulated Data Transmissions
Nishant Mehrotra, Sandesh Rao Mattu, Robert Calderbank
Conventional delay-Doppler (DD) communication and sensing systems require transmitting pilot frames at every channel coherence time interval in order to keep track of channel varia…
Increasing Data Rate through Shaping on Wireless Channels Subject to Mobility and Delay Spread
Sandesh Rao Mattu, Nishant Mehrotra, Robert Calderbank
This letter describes how to improve performance of cellular systems by combining non-equiprobable signaling (shaping) with low-density parity check (LDPC) coding for an orthogonal…
A Reinforcement Learning Framework for Resource Allocation in Uplink Carrier Aggregation in the Presence of Self Interference
Jaswanth Bodempudi, Batta Siva Sairam, Madepalli Haritha +2
Carrier aggregation (CA) is a technique that allows mobile networks to combine multiple carriers to increase user data rate. On the uplink, for power constrained users, this transl…
A Design Framework that Unifies 6G Modulation Schemes for Double Selectivity
Nishant Mehrotra, Sandesh Rao Mattu, Robert Calderbank
There is significant recent interest in designing new modulation schemes for doubly-selective channels with large delay and Doppler spreads, where legacy modulation schemes based o…
Pulse Shaping Filter Design for Integrated Sensing & Communication with Zak-OTFS
Nishant Mehrotra, Sandesh Rao Mattu, Robert Calderbank
Zak-OTFS provides a framework for integrated sensing & communication (ISAC) in high delay and Doppler spread environments. Pulse shaping filter design enables joint optimization of…
Discrete Radar based on Modulo Arithmetic
Nishant Mehrotra, Sandesh Rao Mattu, Saif Khan Mohammed +2
Zak-OTFS is modulation scheme where signals are formed in the delay-Doppler (DD) domain, converted to the time domain (DD) for transmission and reception, then returned to the DD d…
Low-Complexity Equalization of Zak-OTFS in the Frequency Domain
Sandesh Rao Mattu, Nishant Mehrotra, Saif Khan Mohammed +2
4G/5G wireless standards use orthogonal frequency division multiplexing (OFDM) which is robust to frequency selectivity. Equalization is possible with a single tap filter, and low-…
Improving the Spectral Efficiency of Zak-OTFS via Mutually Unbiased Bases
Sandesh Rao Mattu, Nishant Mehrotra, Robert Calderbank
Orthogonal signaling or Nyquist signaling limits the number of information symbols transmitted in bandwidth and time to be , the time-bandwidth product. Transmitting mo…
Differential Communication in Channels with Mobility and Delay Spread using Zak-OTFS
Sandesh Rao Mattu, Nishant Mehrotra, Robert Calderbank
Zak-transform based orthogonal time frequency space (Zak-OTFS) is a delay-Doppler (DD) domain modulation scheme in which the signal processing is carried out in the DD domain. The…
Low-Complexity Frequency Domain Equalization of Zak-OTFS in Doubly-Spread Channels
Saif Khan Mohammed, Sandesh Rao Mattu, Nishant Mehrotra +2
We communicate over wireless channels by first estimating and then equalizing the effective channel. In Zak-OTFS (orthogonal time frequency space) modulation the carrier waveform i…
Zak-OTFS with Spread Carrier Waveforms
Nishant Mehrotra, Sandesh Rao Mattu, Robert Calderbank
Zak-OTFS (orthogonal time frequency space) modulation is a communication framework that parameterizes the wireless channel in the delay-Doppler (DD) domain, where the parameters ma…
Zak-OTFS for Mutually Unbiased Sensing and Communication
Nishant Mehrotra, Sandesh Rao Mattu, Robert Calderbank
Waveforms with ideal ambiguity functions are fundamental to integrated sensing and communication, to active sensing (radar), and to uplink multiple access. We describe a general me…
Low-Complexity Detection of Multiple Preambles in the Presence of Mobility and Delay Spread
Sandesh Rao Mattu, Beyza Dabak, Venkatesh Khammammetti +1
Current wireless infrastructure is optimized to support downlink applications. This paper anticipates the emergence of applications where engineering focus shifts from downlink to…
Delay-Doppler Signal Processing with Zadoff-Chu Sequences
Sandesh Rao Mattu, Imran Ali Khan, Venkatesh Khammammetti +4
Much of the engineering behind current wireless systems has focused on designing an efficient and high-throughput downlink to support human-centric communication such as video stre…
On the Bit Error Performance of OTFS Modulation using Discrete Zak Transform
Vineetha Yogesh, Vighnesh S Bhat, Sandesh Rao Mattu +1
In orthogonal time frequency space (OTFS) modulation, Zak transform approach is a natural approach for converting information symbols multiplexed in the DD domain directly to time…
Learning based Channel Estimation and Phase Noise Compensation in Doubly-Selective Channels
Sandesh Rao Mattu, A. Chockalingam
In this letter, we propose a learning based channel estimation scheme for orthogonal frequency division multiplexing (OFDM) systems in the presence of phase noise in doubly-selecti…
Deep Channel Prediction: A DNN Framework for Receiver Design in Time-Varying Fading Channels
Sandesh Rao Mattu, Lakshmi Narasimhan T, A. Chockalingam
In time-varying fading channels, channel coefficients are estimated using pilot symbols that are transmitted every coherence interval. For channels with high Doppler spread, the ra…