High Accuracy GPS-Free Vehicular Positioning Based on V2V Communications and RSU-Assisted DOA Estimation

Traffic congestion has increased, especially in urban cities with population growth and increase in economic activities. Traffic congestions are responsible for economic losses, environmental pollution and road accidents. This research addresses these challenges, by proposing intelligent transportation system (ITS) based on vehicular communications and vehicular positioning. Roadside units (RSU) are considered for transmitting reference signals for vehicle positioning. Vehicular communication is used to exchange estimated position information among vehicles. Vehicular channel model for urban road is developed using Wireless Insite ray-tracing simulator considering IEEE 802.11p dedicated short range communication (DSRC) band at 5.9 GHz. Direction-of-arrival (DOA) of reference signals are analyzed and fused in the vehicle on-board unit (OBU) to estimate and enhance the vehicle position accuracy. Results show that the capability of the proposed method provides higher positioning accuracy than the state-of-the-art GPS based vehicular positioning. Estimated bit-error-rate (BER) results of developed systems indicate that reliable communication is feasible with vehicle-to-vehicle (V2V) and vehicle-to-roadside unit (V2R), to exchange vehicle position information to surrounding vehicles.