Patent ID: 7705710

Claim:
A method for start and access verification of a motor vehicle by means of a mobile identification transmitter with an evaluation unit arranged in the identification transmitter, the method comprising the following steps executed in any order: at least two antennas arranged in different places on the vehicle each emit a first electromagnetic signal time independently from each other, which is measured by a measuring device in the identification transmitter; the at least two vehicle-side antennas simultaneously emit a second electromagnetic signal which is measured by the measuring device in the identification transmitter; the measuring device measures the field strengths of the first and second electromagnetic signals as components; the measured components of the first electromagnetic signal emitted by the first antenna are written as a first vector, the measured components of the first electromagnetic signal emitted by the second antenna are written as a second vector, and the measured components of the second electromagnetic signal emitted by both the first and second antennas are written as a sum vector; comparing the vector sum of the first and second vectors with the sum vector; and determining whether to provide access to the motor vehicle based on the results of the comparison.