Device and method for sampling rate conversion
AssigneeRohde & Schwarz GmbH & Co. KG
InventorMarkus Freidhof
Life of this patent
Estimating the term…
Abstract
A resampler device and method are used to convert a digital input signal string (Sin) with an input-sampling rate into a digital output signal string (Sout) with a higher output-sampling rate. Prior to interpolation, a time shift (tmod(n)/Tout) is first determined for every sampling time (t′n) of the output signal string (sout) relative to a next sampling time (ti+1) of the input signal string (sin). Then the time shift (Δt(n)/Tout) of the sampling time (t′n) of the output signal string (Sout) relative to the preceding sampling time (ti) of the input signal string (Sin) is determined from the previously determined time shift (tmod(n)/Tout) relative to the next sampling time (ti+1).
Claims11
Device for converting a digital input signal string (Sin) with an input-sampling rate (fin) into a digital output signal string (Sout) with an output-sampling rate (fout) that is higher than the input-sampling rate (fin), comprising:
- an estimating unit (11) that estimates the sampling rate ratio (Rk) between the input-sampling rate (fin) and the output-sampling rate (fout),
- a regulating unit (12) that is connected to the estimating unit (11) and which generates a control signal (RTC,k) as a function of the estimated sampling rate ratio (Rk),
- a timing control unit (13), which initially determines, from the control signal (RTC,k) the time shift tmod(n)/Tout) of each sampling time (t′n) of the output signal string (Sout) relative to the next sequential sampling time (t1+) of the input signal string (Sin), and then establishes therefrom the time shift (Δt(n)/Tout) of the sampling time (t′n) of the output signal string (Sout) relative to the preceding sampling time (ti) of the input signal string (Sin), and
- an interpolator (7) that interpolates, from the sampling times (t′n) determined in the timing control unit (13), the input signal string (Sin) for producing the output signal string (Sout).
Method for converting a digital input signal string (Sin) with an input-sampling rate (fin) into a digital output signal string (Sout) with an output-sampling rate (fout) that is higher than the input-sampling rate (fin), having the following process steps:
- estimating (11) the sampling rate ratio (Rk) between the input-sampling rate (fin) and the output-sampling rate (fout),
- generating a control signal (RTC,k) as a function of the estimated sampling rate ratio (Rk),
- determining from the control signal (RTC,k) a time shift tmod(n)/Tout) of each sampling time (t′n) of the output signal string (Sout) relative to the next sequential sampling time (ti+1) of the input signal string (Sin),
- establishing the time shift (Δt(n)/Tout) of the sampling time (t′n) of the output signal string (Sout) relative to the preceding sampling time (ti) of the input signal string (Sin) from the previously determined time shift tmod(n)/Tout) relative to the next sequential sampling time (ti+1), and
- interpolating (7), from the sampling times (t′1, t′2, . . . t′6) determined in a timing control unit (13), the input signal string (Sin) to produce the output signal string (Sout).
Dependencies are inferred from the claim text.