Patent ID: 8422976

Claim:
An antenna diversity system for receiving broadcast reception of OFDM—modulated signals in vehicles, said system comprising: a receiver having an input and an output; a multi-antenna system having a plurality of antennas and an output comprising an OFDM—modulated reception signal for each of said plurality of antennas; a signal selection switch having an input for receiving at least two reception signals from said plurality of antennas, said signal selection switch for selection of a different reception signal, in terms of diversity, and wherein said signal selection switch has an output in a form of a selected reception signal which is passed to said receiver; and a diversity processor, which assesses a signal quality of the selected OFDM—modulated reception signal arriving at said receiver, and which is configured to activate said signal selection switch to pass a different OFDM—modulated reception signal, in terms of diversity, to said receiver, if interference occurs, by switching over, wherein said diversity processor is configured to receive said selected OFDM—modulated reception signal that is present in said receiver, having the greater frequency bandwidth B of the OFDM—modulated reception signal than the expected bandwidth of the transmission channel; wherein said diversity processor is configured to determine a signal quality of said selected OFDM—modulated reception signal, by dividing its frequency bandwidth B into frequency intervals (Δf), within which the frequency components of said selected reception signal are essentially constant, in each instance, when multipath-propagation is present, wherein said diversity processor is configured so that frequency intervals Δf are formed by means of a plurality of subcarriers, and wherein a set of frequency-interval-specific level values of said frequency intervals Δf are detected by means of the level values of the subcarriers, wherein said processor comprises: an evaluation circuit wherein said set of frequency-interval-specific level values of said frequency intervals Δf of said selected OFDM—modulated reception signal are separately compared with a signal level threshold that is required for interference-free reception, in said evaluation circuit that is a frequency-interval-specific level evaluation of these subcarriers, and the interference rate of said selected OFDM—modulated reception signal is determined by means of evaluation of these measurements over all the frequency intervals (Δf), wherein if interference is detected, said processor passes a different reception signal, in terms of diversity, in a form of a different selected OFDM—modulated reception signal having a lowest interference rate, to said receiver.