Short range motorway communications using a dual-signal receiver

This paper evaluates the performance of a dual-signal receiver (DSR) when used for short-range communications on a motorway. Vehicles send small packets with equal transmitting power to a base station near the motorway using the slotted Aloha protocol. The positions of the vehicles are derived from real vehicle measurements. The measurements are split into three traffic conditions: queuing traffic with low vehicle speeds, heavy traffic with small average headway's, and light traffic. A DSR is used, and compared with a capture receiver. Success probabilities are calculated using a free space power loss model and Rice distribution. The success probabilities are used to analyse the throughput and delay characteristics for the slotted Aloha protocol in the uplink data stream, under different traffic conditions. The results show that the DSR benefits from the near-far effect. The total throughput for all vehicles is significantly higher than for the capture receiver.