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Process and apparatus for translating the sampling rate of a sampled signal

Assignee: Individual
•
Filing: 1981-11-24
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Granted: 1985-05-07
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Expires: 2001-11-24
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Abstract

Abstract Abstract of the Disclosure An input sampling sequence with an input sampling rate is translated into an output sampling sequence with a selectable output sampling rate in a sampling filter. A circuit for forming the time difference of the sampling points forms from the given input sampling rate and the desired output sampling rate a signal corresponding to the time difference and this is used in a translation circuit for converting into data for characterizing the filter coefficients. The sampling filter is conditioned by the selected coefficients from the translation circuit. The invention is suitable for the transmission of sampled data, particularly sampled rates between two systems operating at different clock frequencies.

Inventors

  • 👤 Henry O. Kunz
  • 👤 Roger Lagadec

Bibliographic Details

Application Number —
Jurisdiction CA
Data Source google_patents
Last Synchronized 2026-10-24 03:04
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/06; H03H17/0621; H03H17/0628

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 113 words
A process for translating an input sampling sequence with an input sampling rate into an output sampling sequence with a selectable output sampling rate so that the two sampling sequences have rate spectra which are of identical amplitude in a rate range extending from zero rate to about half the lower of the two sampling rates except for an error portion determined only by the precision of processing the sampled values, comprising determining the instantaneous time difference between the input and output sampling times and producing a control signal representative of that difference; translating the sampling rate; and controlling the sampling rate translation as a function of the characteristics of the control signal.
Claim 2
Dependent Claim 113 words
A process for translating an input sampling sequence with an input sampling rate into an output sampling sequence with a selectable output sampling rate so that the two sampling sequences have rate spectra which are of identical amplitude in a rate range extending from zero rate to about half the lower of the two sampling rates except for an error portion determined only by the precision of processing the sampled values, comprising determining the instantaneous time difference between the input and output sampling times and producing a control signal representative of that difference; translating the sampling rate; and controlling the sampling rate translation as a function of the characteristics of the control signal.
Claim 3
Dependent Claim 45 words
A process according to claim 1 wherein the sampling rate translation is controlled by using the control signal representative of the instantaneous time difference to select an instantaneous sampling filter coefficient set and conditioning an at least single-stage sampling filter with the selected coefficient set.
Claim 4
Dependent Claim 24 words
A process according to claim 1 or 2 wherein the output sampling rate is derived as a fixed ratio of the input sampling rate.
Claim 5
Dependent Claim 37 words
A process according to claim 1 or 2 and including suppressing short-term fluctuations in the time intervals between samples, and then determining the instantaneous time difference between the input and output sampling times between successive sampling times.
Claim 6
Dependent Claim 32 words
A process according to claim 1 or 2 wherein determinations of the instantaneous time difference between the input and output sampling times are time-averaged to increase the precision thereof. . . .
Claim 7
Dependent Claim 69 words
A process according to claim 2 wherein the sampling rate is translated using at least one single-stage sampling filter to an output sampling rate greater that the input sampling rate, and wherein the control signal represents a translation rate which is a time-quantization of the instantaneous time difference, the adaptation to the output sampling rate being accomplished by reading out the sampling sequence only at the output sampling times.
Claim 8
Dependent Claim 70 words
A process according to claim 2 wherein the input sampling sequence is converted into a translation sampling sequence by inserting an additional number of zero sampling values dependent upon the time difference such that the translation sampling rate corresponds to the quantization of the instantaneous time difference and wherein the adaptation to the output sampling rate is accomplished by reducing the sampling rate using at least one single-stage sampling filter.
Claim 9
Dependent Claim 21 words
A process according to claim 7 wherein the selection of adaption is determined by the relationship between the two sampling rates.
Claim 10
Dependent Claim 20 words
A process according to claim 6, 7 or 8 wherein multiplications are not performed where the sampling rates are zero.
Claim 11
Dependent Claim 26 words
A process according to claim 6,7 or 8 wherein the increase or decrease in the sampling rate in each case is by a power of 2.
Claim 12
Dependent Claim 27 words
A process according to claim 6,7 or 8 wherein, before translating the sampling rate, the input sampling rate is increased by a fixed ratio with a prefilter.
Claim 13
Dependent Claim 27 words
A process according to claim 6,7 or 8 wherein, after translating the sampling rate, the output sampling rate is reduced by a fixed ratio using a postfilter.
Claim 14
Dependent Claim 49 words
A process according to claim 6, wherein prior to the translation of the sampling rate, the input sampling rate is additionally increased by a fixed ratio using a prefilter and, after translating the sampling rate, the output sampling rate is correspondingly reduced by the same ratio using a postfilter.
Claim 15
Dependent Claim 33 words
A process according to claim 13, wherein sampling filters are used for increasing or decreasing the sampling rate and are equivalent to at least single-stage cascade of identical sampling filters with identical coefficients.
Claim 16
Dependent Claim 42 words
A process according to claim 13, wherein sampling filters are used for increasing or decreasing the sampling rate, the coefficients of said filters being represented without quanitization errors in a representation in fixed word length and with a selectable form of quantization.
Claim 17
Dependent Claim 60 words
A process according to claim 1 or 2, wherein the sampling filter for translating the input into the output sampling sequence is a Fourier processor for calculating the rate spectrum of the input sampling sequence, followed by a processor for performing the filter operations in the Fourier domain and a second Fourier processor for transforming back into the time domain.
Claim 18
Independent Claim 150 words
An apparatus for translating an input sampling sequence with an input sampling rate into an output sampling sequence with a selectable output sampling rate so that the two sampling sequences have a rate spectra which are of identical amplitude in a rate range extending from zero rate to about half the lower of the two sampling rates except for an error portion determined only by the precision of processing the sampled values, comprising the combination of circuit means for determining the instantaneous time difference between the input and output sampling times and for producing signals representative of that difference; translation circuit means for converting said signals representative of time difference into data representative of a set of filter coefficients, and sampling filter circuit means for converting the input sampling sequence at the input sampling rate into an output sampling sequence at the output rate in response to said filter coefficients.
Claim 19
Independent Claim 150 words
An apparatus for translating an input sampling sequence with an input sampling rate into an output sampling sequence with a selectable output sampling rate so that the two sampling sequences have a rate spectra which are of identical amplitude in a rate range extending from zero rate to about half the lower of the two sampling rates except for an error portion determined only by the precision of processing the sampled values, comprising the combination of circuit means for determining the instantaneous time difference between the input and output sampling times and for producing signals representative of that difference; translation circuit means for converting said signals representative of time difference into data representative of a set of filter coefficients, and sampling filter circuit means for converting the input sampling sequence at the input sampling rate into an output sampling sequence at the output rate in response to said filter coefficients.
Claim 20
Dependent Claim 66 words
An apparatus according to claim 17, wherein said circuit means for producing signals representative of said time difference comprises an oscillator phase-coupled with the input sampling rate and having frequency which is an integral multiple of the input sampling rate, and a counter stage for determining the time intervals between the output sampling times as an integral number of time intervals of the oscillator output signal.
Claim 21
Dependent Claim 34 words
An apparatus according to claim 17, wherein the output timing signal is supplied from a translation circuit, whose input is the input signal and which multiplies the input timing frequency by a fixed value.
Claim 22
Dependent Claim 32 words
An apparatus according to claim 18, and including circuit means for time-averaging the instantaneous time difference said circuit being connected between said circuit for forming the time difference and said translation circuit.
Claim 23
Dependent Claim 41 words
An apparatus according to claim 17, wherein the sampling filter comprises an at least single-stage cascade of partial filters with increasing sampling rates, followed by a circuit for subsampling the sequence with the highest sampling rate fed in by the cascade.
Claim 24
Dependent Claim 47 words
An apparatus according to claim 17, wherein the sampling filter comprises a series connection of a circuit for inserting zero sampling values and a cascade of n partial filters with stepwise decreasing sampling rates, the number n of partial filters being equal to or greater than 1.
Claim 25
Dependent Claim 38 words
An apparatus according to claim 21 or 22, wherein a comparison circuit for comparing the sampling rates is coupled to the sampling filter and wherein the sampling filter operates as a function of the result of the comparison.
Claim 26
Dependent Claim 51 words
An apparatus according to claim 17, wherein a prefilter is connected upstream of the sampling filter input and increases the sampling rate by a fixed amount, whilst a corresponding frequency multiplication circuit is positioned upstream of the difference forming circuit input, and increases the input sampling rate by the same ratio.
Claim 27
Dependent Claim 54 words
An apparatus according to claim 17, wherein a postfilter is connected downstream of the sampling filter and reduces the sampling rate by a fixed ratio, and a frequency multiplication circuit for the output sampling rate is connected upstream of the difference forming circuit input, and increases the output sampling rate by the same ratio.
Claim 28
Independent Claim 39 words
An apparatus according to claims 24 and 25, wherein a prefilter and postfilter are provided connected to the sampling filter and a frequency multiplier acting on the difference forming circuit for the input sampling rate and output sampling rate.
Claim 29
Dependent Claim 45 words
A circuit arrangement according to claim 17, wherein the sampling filter comprises at least a single-stage cascade of. partial filters and at least one partial filter can be represented as an at least single-stage cascade of identical subfilters, which all have identical and equivalent coefficients.

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