Unidirectional wireless ranging method and unidirectional wireless ranging device for vehicles

The embodiment of the invention discloses a unidirectional wireless ranging method for vehicles. The method includes the following steps: a receiver receives the ranging signal transmitted by a transmitter arranged on a target vehicle, and the receiving time of the ranging signal received by the receiver is recorded; according to the frequency of the ranging signal, the transmission time of the ranging signal transmitted by the transmitter is acquired; and according to the time difference between the transmission time of the ranging signal and the receiving time of the ranging signal received by the receiver, the distance between the target vehicle with the transmitter and the receiver is calculated. The embodiment of the invention also discloses a unidirectional wireless ranging device and the transmitter for vehicles. The adoption of the invention can realize non-return or one-way wireless ranging, shorten the response time for ranging and reduce the transmission loss of ranging signals and the error of received transmitted wireless ranging signals as the result of the affection of obstacles.