"Reshaping the ISAC Tradeoff Under OFDM Signaling: A Probabilistic Constellation Shaping Approach" presented by Dr. Zhen Du, Dr. Yifeng Xiong and Dr. Fan Liu. Based on the IEEE Xplore® article under the same title. Published IEEE Transactions on Signal Processing, September 2024. Visit article article here.
Integrated Sensing and Communications (ISAC) is widely recognized as a key technological driver for next-generation wireless systems. Exploiting orthogonal frequency division multiplexing (OFDM) communication waveforms for sensing offers a low-cost and hardware-efficient approach toward practical ISAC deployment. However, the impact of communication randomness on sensing performance remains insufficiently quantified, and the sensing-communication trade-off is often difficult to flexibly adjust according to diverse service requirements.
This webinar will present a theoretical framework that characterizes the randomness of the radar ambiguity function under communication signaling. By analyzing the matched filtering behavior, the presenters will reveal a fundamental result: sensing performance is determined by the fourth-order moment of constellation amplitudes. Based on this insight, they outline an optimal probabilistic constellation shaping strategy to achieve a controllable sensing-communication trade-off. The proposed approach depends only on the probability distribution of the transmitted constellation, without requiring channel state information or specific data realizations, leading to low complexity and practical implementability. Extensions of the framework to mismatched filtering conditions will also be discussed.
