Distributed Sensing and Centric Computing via FMCW Waveform in Wireless Sensor Network

Wireless Sensor Networks (WSNs) are widely used for environmental sensing, where numerous low-complexity sensors are deployed to collect and partially process measurements. The data is then transmitted to a computing center for information fusion and estimation. Integrated Sensing and Communications (ISAC) is a recent approach that enables simultaneous sensing and data transmission by designing the waveform, architecture, and protocol. This approach has the potential to improve real-time computing and spectral utilization in WSNs. In this paper, we propose a frequency-modulated continuous-wave (FMCW)-based waveform for ISAC, which is cheaper and more suitable for WSNs than other waveforms. We use a pulse-by-pulse modulation scheme to embed communication symbols across all pulses, minimizing the averaged mean square error (AMSE) of these symbols. Additionally, we design the combiner matrix of the computing center in the presence of channel uncertainty. Numerical experiments are conducted to evaluate the effectiveness of the proposed approach.