Abstract: 
We will start by reviewing the parametric family of Zak-OTFS pulsone waveforms that can be matched to the delay and Doppler spreads of different propagation environments. In particular, we will describe how the (point) pulsone signal in the time domain realizes a quasi-periodic localized function on the delay-Doppler (DD) domain. The characteristic structure of a pulsone is a train of pulses modulated by a tone, a signal with unattractive peak-to-average power ratio (PAPR). We will review system performance in the crystalline regime where the delay period of the pulsone is greater than the delay spread of the channel, and the Doppler period of the pulsone is greater than the Doppler spread of the channel. When channel sensing and data transmission take place in separate subframes, the point pulsone used to sense the channel does not interfere with the point pulsones used to transmit data. We will describe how the I/O relation of the sampled communication system can be read off from the response to the point pulsone used for channel sensing.
We will introduce the notion of filtering in the discrete delay-Doppler domain. We will describe how to construct spread waveforms with desirable characteristics by applying a chirp filter in the discrete DD domain to a point pulsone. One desirable characteristic is low PAPR, about 6dB for the exemplar spread pulsone, compared with about 15dB for the point pulsone. A second desirable characteristic is the ability to read off the I/O relation of the sampled communication system provided a second crystallization condition is satisfied. 
We will demonstrate how to integrate sensing and communication within a single Zak-OTFS subframe through the combination of a spread pulsone used for channel sensing and point pulsones for data transmission. The filter in the discrete DD domain enables coexistence by minimizing interference between sensing and data transmission. We will demonstrate that sharing DD domain resources in this way increases effective throughput compared with traditional approaches that use guard bands to divide DD domain resources between sensing and communication. 
This is joint work with Muhammad Ubadah, Saif Khan Mohammed, Ronny Hadani, Shachar Kons, and Ananthanarayanan Chockalingam – see  https://arxiv.org/abs/2404.04182 for more details.

Bio:

Dr. Calderbank directs the Rhodes Information Initiative at Duke University, where he is a Distinguished Professor. He is known for contributions to voiceband modem technology, to quantum information theory, and for co-invention of space-time codes for wireless communication. His research papers have been cited more than 50,000 times, and his inventions are found in billions of consumer devices. Dr. Calderbank was elected to the National Academy of Engineering in 2005, to the National Academy of Inventors in 2015, and to the American Academy of Arts and Sciences in 2022. He has received a number of awards, including the 2013 IEEE Hamming Medal for contributions to information transmission, and the 2015 Claude E. Shannon Award.