Patent ID: 8688155
Filing Date: 2014-04-01
Classification: H04B,H04H,H04L

Abstract:
1. A circuit to synchronize communication signals between a repeater station of a single-frequency simulcast radio communication network and user terminals with respect to a universal frequency reference signal sent by a central station of the network communicating with the repeater station, the circuit comprising: an oscillator circuit adapted to produce a local frequency reference signal for a tuning receiver of the station to a first operating frequency for transmitting the signals received from the central station, and for a tuning transmitter of the station to a second operating frequency for transmitting the signals to the user terminals; means for determining a frequency offset between the universal frequency reference signal received from the central station and the local frequency reference signal; first frequency control means, for tuning the oscillator circuit to the frequency of the universal reference signal, and arranged to vary its oscillation frequency on the basis of the determined frequency offset, in a first feedback control loop configuration; and second frequency control means arranged to provide the tuning transmitter with a signal for compensating a residual difference in synchronization between the oscillation frequency of the oscillator circuit, with respect to which the tuning transmitter is tuned, and the frequency of the universal reference signal, in a second direct control loop configuration.