System for providing information relating to the source frequency in a digital receive-transmit system

A method for measuring frequency of a data source comprising the following steps:

• a) processing a first signal (FS) at a first frequency (FQ1) associated with the data source by performing a frequency division according to a first factor (N);
• b) processing a second signal (FT) at a second frequency (FQ2) associated with a transmission flow by performing a frequency division according to a second factor (M);
• c) using the second frequency (FQ2) of the second signal (FT), divided by the second factor (M) as a reference frequency (F, FR) to measure the first frequency (FQ1) divided by the first factor (N) of the first signal (FT);
• d) sending a coded measurement (U) of the first frequency (FQ1) to a receiver (R) at a preset rate (FP) and a precision (QP) as determined by the preset rate (FP);
• characterized in that the method provides the following additional steps:
• c′) selecting the first and second factors (N, M) to set a measuring rate (F) determining a higher number of measurements (NUM) in the time interval (TP) compared to the number of measurements as determined by the preset rate (FP);
• c″) calculating the mean value over said time interval (TP) of said higher number of measurements (NUM), obtaining a frequency measurement (U′) associated with a precision (Q) that is higher than the precision (QP) determined by the preset rate (FP) and a frequency equal to the preset rate (FP);
• and
• c′″) coding the frequency measurement (U′) to obtain a coded signal (U) having the same frequency of the preset rate (FP), so that compared to the receiver (R) the coded signal has a mean value equal to that of the frequency measurement (U′) and an error that varies more rapidly.

A transmission apparatus, for sending clock frequency value of a data source at a preset rate, in order to ensure correct reception of information at a receiver means (R), comprising:

• a first signal (FS) at a first frequency (FQ1) associated with the data source;
• a second signal (FT) at a second frequency (FQ2) associated with the transmission system, said second signal (FT) used as a reference signal to measure the first signal (FS);
• and
• measuring means (CP, CN, CM) for measuring the first frequency (FQ1) of the first signal (FS) compared to the second frequency (FQ2) of the second signal (FT), wherein said measuring means (CP, CN, CM) for frequency measurement (U′) of the first frequency (FQ1) of the first signal (FS) are prearranged to perform said measurement (U′) at a measuring rate (F) higher than a preset rate (FP), wherein a post-processing means (P) is provided to code the frequency measurement (U′) and supply a coded signal (U) at said preset rate (FP) to the receiver means (R), wherein the post-processing means (P) maintains in the frequency measurement (U′) a precision (Q) supplied by the measurement means (CP, CN, CM) and determined by the measuring rate (F), and wherein the precision (Q) is higher than a precision (QP) determined by the preset rate (FP).