Design and performance evaluation of acoustic vehicle-to-pedestrian communication system

Abstract

There is a greater risk of vehicle-pedestrian accidents when vehicles are traveling at low speeds. To cope with this problem, acoustic vehicle-topedestrian communication that can measure relative speed between vehicle and pedestrian is proposed. The proposed system is easy to implement on both the vehicle and pedestrian side, and will promote improved traffic safety. The proposed system is affected by noise, Doppler shift, fading, delay spread, and Doppler spread, and uses an orthogonal frequency division multiplexing signal, error correcting code, frequency diversity, and null subcarrier to counteract these effects. The performance of the proposed system was evaluated in outdoor experiments using real vehicles. In a line-of-sight environment, the proposed system measured relative speed and communicated without bit error at a distance of 40 m with a transmitter moving at about 2.78 m s −1 and a stationary receiver. In a non-line-of-sight environment, the proposed system measured relative speed and communicated without bit error at a 9 m distance between transmitter and receiver, which is a sufficient distance to prevent vehiclepedestrian accidents.

An efficient subcarrier arrangement for airborne OFDM communication using parametric loudspeaker

“…Numerous studies on acoustic communication have been reported. [13][14][15][16][17][18] Compared to similar studies of wireless communication using ultrasonic waves, 19,20) there are two main advantages of wireless communication using audible sound: (1) the availability of microphones in commercial devices and (2) the ease of implementing the modem as software. On the other hand, there also two disadvantages: (1)′ the communication signal at an audible frequency is unpleasant to the human ear and (2)′ communication is not very secure.…”