Performance of PTS reduction technique using a Stepped-Carrier OFDM scheme for JARC applications

Orthogonal Frequency Division Multiplexing (OFDM) is a promising option for integrating radar sensing and vehicular communication in the frequency range of 77-81GHz. Although recent publications emphasize benefits of OFDM for achieving reliable radar detection and efficient vehicular communication, the practical implementation of this technology is hindered by the requirement of high-speed Analog to Digital Converters (ADC) to handle the wideband signal. Stepped-Carrier OFDM (S-C OFDM) appears to be a promising solution to address this challenge, as it can effectively reduce the baseband bandwidth of the signal while still meeting requirements for automotive radar applications. Nevertheless, one major disadvantage of OFDM systems is the high peak-to-average power ratio (PAPR) which can cause in-band distortion and out-of-band radiation due to non-linearities in high-power amplifiers. Over the years, several techniques have been proposed to address this issue, including partial transmit sequence (PTS), coding, interleaving or selective mapping. This paper focuses on the PTS reduction technique, which is widely recognized in the literature for its distortionless nature and minimal impact on the bit error rate (BER) performance. It is specifically suitable for joint automotive radar and communication (JARC) applications, despite its computationally demanding nature. Due to the range resolution requirements in OFDM radar, a large bandwidth is imposed, resulting in decreased computational complexity performance. As a novel contribution to the existing literature, our work highlights the beneficial influence of reducing the baseband bandwidth while using stepped-carrier OFDM on the computational complexity effort of the PTS technique. Furthermore, it demonstrates the ability to meet the requirements of an automotive radar detection system.