I. INTRODUCTION
With an important amount of unused spectrum, the subTeraHertz (sub-THz) frequencies between 90 and 300 GHz are contemplated to realize high-data rate wireless communications and hence to fulfill the requirements of the nextgeneration of wireless networks [1]. Several beyond 5G applications are considered for sub-THz systems [2]: high capacity backhaul, enhanced hot-spot kiosk and also short-range communications. Despite the evolution of semi-conductor technology, the design of new physical layer algorithms is required to achieve high data-rate sub-THz communications. Traditional coherent schemes do not consider the specific radio-frequency (RF) impairments related to the sub-THz bands, and therefore, cannot be directly used in these frequencies. In particular, subTHz systems suffer from strong phase impairments due to the poor performance of high-frequency oscillators. We therefore investigate in this paper the optimization of the digital signal processing to mitigate the impact of phase noise (PN) on communication performance within the frame of the highcapacity backhaul.