Alternative frequency service verification

摘要

An alternative frequency of e. g. a digital shortwave signal like a DRM signal can easily and satisfactorily be checked whether or not the same service is transmitted before a fast seamless switching to this alternative frequency can be performed. The inventive method to perform such a checking is characterized by a respective correlation of at least two sets of samples taken from the signal transmitted on the alternative frequency having a predetermined time relationship (DELTAtcorr) and a comparison of said respective correlation results, i.e. comparison of the time (t1) of occurance of a correlation peak included in a first correlation result with the time (t2) of occurance of a correlation peak included in a respective further correlation result, to verify that both services are the same when the time relationship (|t2 l -t1|) between said correlation peaks is the same as said predetermined time relationship (DELTAtcorr) of the at least two sets of samples.