Patent ID: 7149312

Claim:
Method to retrieve RDS information by filtering and transforming an incoming multiplex signal (m(t)) into an amplitude demodulated RDS signal (m RDS (t)), wherein an amplitude modulated RDS signal (m c (t)) is derived on basis of an intermediate signal (m a (t)) obtained during an extraction of a stereo-difference signal (m d (t)) from the incoming multiplex signal, and the intermediate signal (m a (t)) is obtained by multiplying the multiplex signal (m(t)) with the second harmonic of a pilot carrier (2sin(2ω pil t)), wherein the amplitude modulated RDS signal (m c (t)) is derived by subtracting a stereo-sum signal (m s (t)) multiplied by the second harmonic of a pilot carrier (2sin(2ω pil t)) from the intermediate signal (m a (t)).