Method, system and device for reducing adjacent-channel interference in electronic tollof collection (ETC) system

Abstract

The invention discloses a method, a system and a device for reducing adjacent-channel interference in an electronic tollof collection (ETC) system. A transmitting and receiving integrated antenna is modified to form transmitting and receiving separated antennae; software of a controller is modified to control the transmitting antenna to send interference waves when effective data signals are sent completely; meanwhile, the receiving antenna waits for receiving a response signal returned by an on-board unit; and channel signals corresponding to a lane cover the lane without time slot in a full duplex communication mode, so that signals of adjacent lanes are not inserted in the time slot of the on-board unit (OBU) in the lane, and the adjacent-channel interference can be effectively reduced and even eliminated. In addition, the technical scheme is independent of other equipment, the antennae work independently, and hardware cost is low.

Description

technical field [0001] The invention relates to dedicated short-range communication technology, in particular to a method, system and device for reducing adjacent channel interference in an ETC system. Background technique [0002] ETC (Electronic Tollof Collection, electronic non-parking toll collection system) is a special short-range microwave communication technology, through the information exchange between the Road-side Unit (Road-side Unit, RSU) and the vehicle-mounted unit (On-Board Unit, OBU). It is a fully automatic charging method that automatically completes the deduction of vehicle tolls when the driver does not stop and there is no toll collector to pay the toll. ETC has the advantages of fast passage without parking, high traffic capacity and service level, no cash transaction, simplified toll management, and reduced environmental pollution. [0003] On-board unit OBU is a mobile equipment identification device with microwave communication function and inform...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, the method of distinguishing channel numbers is mostly used to reduce adjacent channel interference. However, due to the wideband reception of OBU and the broadcast search method of RSU, in the search process, the channel distinction loses its original intention and is not very good. Solve the problem of adjacent channel interference

Another way to prevent adjacent channel interference is to connect the controllers of two adjacent lanes with a synchronizer, so that the search signals of different channels sent by the adjacent two antennas are sent out synchronously, so that the stronger signal of this lane suppresses the adjacent channel. Lane divergent signals to reduce the probability of adjacent channel interference, but this method needs to rely on synchronizers, which increases hardware costs and construction workload, and if the synchronizer fails, it cannot limit the occurrence of adjacent channel interference

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