Patent ID: 8306168

Claim:
A reception system for frequency modulated or phase modulated high frequency signals for vehicles comprising: a multi antenna system, comprising at least two antennas (A 1 , A 2 ); at least one individually adjustable phase rotation element Φ 1 situated in a reception path of at least one of said at least two antennas; a linear combination circuit ( 5 ) for combining signals from said at least two antennas; a receiver circuit ( 2 ) for receiving signals from at least one of said at least two antennas; at least one individually adjustable switching element (S 1 , S 2 ) for switching through or interrupting a signal flow from at least one of said at least two antennas, wherein said at least one switching element is positioned in a signal path of at least one of said at least two antennas; wherein said at least one individually adjustable phase rotation element and said at least one individually adjustable switching element are in communication with said linear combination circuit ( 5 ) to form a combined signal wherein said combined signal is passed to said receiver circuit ( 2 ); a selection device ( 14 ) disposed in said receiver circuit ( 2 ) for extensively separate determination of said reception signal and for determination of a noise signal ( 21 ) of said combined signal, for separate determination of a useful signal level ( 4 ) and a noise signal level ( 23 ); a plurality of test circuits implemented by settings of said switching element and at least one individually adjustable phase rotation element at a period Tz of the test circuits of less than approximately 100 symbol lengths of the data signal to be transmitted; a logic unit ( 7 ) for subsequent determination of a signal-to-noise ratio (SNR); wherein said logic unit is configured to determine useful signal levels of the individual reception signals (e 1 , e 2 ) by performing the following steps: conducting a test cycle; switching said individually adjustable switching element of only one reception signal (E 1 , E 2 ) in each instance of said at least two antennas, within a scope of said test cycle, wherein as a criterion for the further setting process, only those signals are selected wherein a signal to noise ratio (SNR) exceeds a required minimum measure; recording phase deviations of the useful reception signals ( 4 ) from one another in a fixed text cycle time interval (Tz) that are sufficiently small in comparison with a ratio of a wavelength to a travel speed, wherein said step of determining phase deviations occurs one after the other to determine phase deviations for each successive antenna; setting said phase rotation elements (Φ 1 , Φ 2 ), controlled by said logic control circuit ( 7 ), so that all of a set of useful reception signals of said reception signals assume a substantially common phase.