*Article* **A W-Band Communication and Sensing Convergence System Enabled by Single OFDM Waveform**

**Nazar Muhammad Idrees <sup>1</sup> , Zijie Lu 1, Muhammad Saqlain 1, Hongqi Zhang 1, Shiwei Wang 1, Lu Zhang <sup>1</sup> and Xianbin Yu 1,2,\***


**Abstract:** Convergence of communication and sensing is highly desirable for future wireless systems. This paper presents a converged millimeter-wave system using a single orthogonal frequency division multiplexing (OFDM) waveform and proposes a novel method, based on the zero-delay shift for the received echoes, to extend the sensing range beyond the cyclic prefix interval (CPI). Both simulation and proof-of-concept experiments evaluate the performance of the proposed system at 97 GHz. The experiment uses a W-band heterodyne structure to transmit/receive an OFDM waveform featuring 3.9 GHz bandwidth with quadrature amplitude modulation (16-QAM). The proposed approach successfully achieves a range resolution of 0.042 m and a speed resolution of 0.79 m/s with an extended range, which agree well with the simulation. Meanwhile, based on the same OFDM waveform, it also achieves a bit-error-rate (BER) 10−2, below the forward error-correction threshold. Our proposed system is expected to be a significant step forward for future wireless convergence applications.

**Keywords:** communication and sensing; cyclic prefix interval (CPI); orthogonal frequency division multiplexing (OFDM); range extension
