Using adaptive beamforming in a transmitter (or receiver) to reduce the impact of a non-trustworthy receiver (or transmitter)

摘要

A first embodiment of the invention concerns a transmitting device 19 which ascertains whether a receiving device 66 which is situated within an emission region (4, 4 ) of the transmitting device is trustworthy. If it is determined that receiving device 66 is non-trustworthy (e.g. that it is an eavesdropper) then the transmitting device adapts the field strength of transmissions in the direction of the non-trustworthy device 66, by reducing transmission power in that direction so that the emission region shrinks 9. In a second embodiment a receiving device (19, Fig 9) determines whether a transmitting device (85, Fig 9) is trustworthy. If it is determined to be non-trustworthy, e.g. if it is determined to be transmitting incorrectly due to a defect, the receiver reduces its sensitivity to transmissions from the non-trustworthy transmitting device. Assessment of trustworthiness may be made on the basis of digital signatures or certificates, or using mobility information. The present invention finds particular application in C2X systems, i.e. car-to-car communication or car-to-infrastructure communication systems.