CP-DSSS for Radar-Centric Integrated Sensing and Communication

The application of cyclic-prefix direct-sequence spread spectrum (CP-DSSS) is mainly known for communication purposes. Nevertheless, this technique offers a promising potential for radar-centric integrated sensing and communication (ISAC). CP-DSSS combined with Zadoff-Chu (ZC) sequences spreads each transmit symbol, belonging to a digital modulation constellation, to the length of the ZC sequence. Consequently, a CP-DSSS symbol represents the sum of multiple modulation symbols, each of it convolved with a circularly-shifted version of a ZC sequence. To enable ISAC with CP-DSSS, modulation symbols are allocated for radar sensing and communication in a way that portions of the CP-DSSS symbols in the discrete-time domain belonging to each of the applications are orthogonal in the discrete-time domain in the receiver. This paper demonstrates the suitability of CP-DSSS in combination with ZC sequences for radar sensing and communication simultaneously, which is supported by simulation and measurements.