Fm-receiver for receiving fm-signals with transmission identification

Abstract

FM-receiver for receiving an FM-signal with transmission identification. An aerial input is connected to a tuning unit (1) to which there are connected, in succession, an IF-unit (2), an FM-detection circuit (3), a pilot regeneration circuit (10) for regenerating a pilot, a demodulation arrangement (12) for demodulating the code signal which contains transmission identification information, and a clock regeneration circuit (18) which is connected to both the pilot regeneration circuit (10) and the demodulation arrangement (12). The clock regeneration circuit comprises a resettable phase search circuit (18') for producing a clock signal whose frequency is derived from the regenerated pilot and whose phase is derived from the demodulated code signal, a clock-controlled decoding circuit (13) for decoding the code signal and a clock-controlled signal processing unit (17). For the purpose of stabilizing the processing, for example, for the reproduction of the transmission identification information, more specifically with mobile reception, use is made, in the event of disturbances of the code signal, of correctly decoded bits which were stored during undisturbed reception in a memory circuit ( 15). Only in the event of extreme interferences the phase search circuit (18') of the clock regeneration circuit (18) and also the other clock-controlled circuits (13-17) are reset to correct a possible phase slip of the clock signal.