“…However, satellite-based positioning systems suffer a severe deterioration due to frequent blockage and degradation in dense urban environments [6], [7]. To make matters worse, GNSS jammers and cycle slips in the real time kinematic (RTK) approaches would also inevitably lead to undesirable system outages [8], [9]. Fortunately, the growing ubiquity of cellular vehicle-to-everything (C-V2X) networks can be used to provide self-contained positioning services, such as the downlink time difference of arrival (DL-TDOA) approaches in the Long-Term Evolution (LTE) and fifth generation (5G) standard releases of the Third Generation Partnership Project (3GPP) [10], [11].…”