DOI: 10.1109/TMTT.2024.3487295   IEEEXplore: https://ieeexplore.ieee.org/document/10747703

Orthogonal frequency-division multiplexing (OFDM)-based integrated sensing and communication system (ISAC) with over-the-air (OTA) synchronization of incoming signals.

79 GHz (POC - proof of concept system).

OFDM based service is very robust against intersymbol interference (ISI). Forward error correction (FEC) eliminates or significantly reduces bit errors after decoding to improve radar and communication system performance. The synchronization process relies on estimating the time offset (TO), frequency offset (FO) and sampling frequency offset (SFO) of the received signals. TO and FO are corrected for in the synchronization process by first estimating the coarse offsets with the Schmidl and Cox (S&C) algorithm. TO is then finely estimated by cross-correlating the receive signal and the first preamble OFDM symbol to set the starting point for the receive signal. SFO correction first estimates the offset from correlation of other preamble OFDM symbols, refines the estimate based on examination of pilot subcarriers, and corrects the offset calculation by resampling.

6G mobile communication systems.

< 50 Hz frequency error; < 0.1 ppm sampling frequency error (simulation); 0.97 Gb/s data rate (communication system simulation), 0.99 Gb/s POC; 153.49 m ISI-free maximum range; 0.3 m range resolution; 48.83 KHz ISI-free maximum Doppler shift (radar system simulation).