EP3878098A1 - Interpolateur a rang eleve - Google Patents
Interpolateur a rang eleveInfo
- Publication number
- EP3878098A1 EP3878098A1 EP19794584.3A EP19794584A EP3878098A1 EP 3878098 A1 EP3878098 A1 EP 3878098A1 EP 19794584 A EP19794584 A EP 19794584A EP 3878098 A1 EP3878098 A1 EP 3878098A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- interpolation
- signal
- interpolator
- stage
- ratio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005070 sampling Methods 0.000 claims abstract description 55
- 230000000903 blocking effect Effects 0.000 claims abstract description 29
- 238000001914 filtration Methods 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 25
- 230000004044 response Effects 0.000 claims description 40
- 230000000737 periodic effect Effects 0.000 claims description 22
- 238000003780 insertion Methods 0.000 claims description 5
- 230000037431 insertion Effects 0.000 claims description 5
- 238000001228 spectrum Methods 0.000 description 23
- 230000003595 spectral effect Effects 0.000 description 16
- 230000006870 function Effects 0.000 description 10
- 230000002238 attenuated effect Effects 0.000 description 8
- 238000001413 far-infrared spectroscopy Methods 0.000 description 7
- 239000000523 sample Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/06—Non-recursive filters
- H03H17/0621—Non-recursive filters with input-sampling frequency and output-delivery frequency which differ, e.g. extrapolation; Anti-aliasing
- H03H17/0635—Non-recursive filters with input-sampling frequency and output-delivery frequency which differ, e.g. extrapolation; Anti-aliasing characterized by the ratio between the input-sampling and output-delivery frequencies
- H03H17/065—Non-recursive filters with input-sampling frequency and output-delivery frequency which differ, e.g. extrapolation; Anti-aliasing characterized by the ratio between the input-sampling and output-delivery frequencies the ratio being integer
- H03H17/0657—Non-recursive filters with input-sampling frequency and output-delivery frequency which differ, e.g. extrapolation; Anti-aliasing characterized by the ratio between the input-sampling and output-delivery frequencies the ratio being integer where the output-delivery frequency is higher than the input sampling frequency, i.e. interpolation
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/0223—Computation saving measures; Accelerating measures
Definitions
- the invention relates to the field of digital signal processing, and more particularly relates to the production of a high-rank interpolator allowing real-time processing at high speed.
- Interpolating a digital signal is a common operation in a digital signal processing chain. It consists in bringing the sampling frequency of a signal from a first frequency to a second, higher frequency, by calculating intermediate samples between each sample of the original signal. This is the case, for example, when a signal must be brought to a precise sampling frequency for processing purposes, or when two or more signals sampled at very different frequencies are subject to joint processing, this which requires the harmonization of their sampling frequency beforehand.
- This second scenario occurs for example when a signal having a very high frequency band, and therefore sampled at a very high frequency, must be modulated by a modulating signal of narrow band and the sampling frequency of which is optimized for this band.
- the two signals then have a high sampling frequency ratio. To achieve modulation, that is to say the product of the two signals, it is necessary to first bring the two signals to a common sampling frequency.
- the interpolation of a signal is generally done in two stages:
- the signal is first oversampled, that is to say that (n - 1) zeros are inserted between each original sample, n being the ratio of the sampling frequencies, to obtain a signal whose spectrum has n identical periods in the output spectral domain, and - the oversampled signal is filtered so as to attenuate the (n - 1) parasitic periods of the spectrum so as to keep only the useful period, but there are many other forms of interpolators.
- ratio the value corresponding to the ratio of the output sampling frequency to the input sampling frequency of an interpolator or an interpolation stage.
- the term ratio is equivalent to the term "factor”, “ratio” or "order”, which can be found in the literature.
- the sampling frequency ratio is integer, factorizable and high (typically, of the order of one or more tens).
- the useful band of the input signal is small compared to that of the output signal, the sampling frequency of the input signal must be as low as possible while respecting the Shannon criterion, in order to limit as much as possible the resources necessary for developing the signal, whether: ⁇ computing resources in the event of real-time calculation, these resources being all the less used when the sampling frequency is low, or
- An aim of the interpolation is to attenuate according to a specified template the periodicities of the spectrum due to oversampling, while modifying the spectrum of the useful part of the interpolated signal as little as possible,
- interpolation can prove to be costly in computing time, and therefore difficult to implement on a software platform with limited computing power, such as, for example, a DSP (English acronym for Digital Signal Processor). digital signal), an FPGA (English acronym for Field Programmable Gate Array, or programmable door network), an ASIC (acronym for Application-Specific Integrated Circuit, or integrated circuit specific to an application), or any hardware target allowing the necessary processing operations to be carried out, such as a processor, in particular when the processing operations must be carried out in real time and the interpolation ratio is high. It can also prove to be inexpensive to implement but inefficient spectrally.
- DSP Digital Signal Processor
- FPGA Field Programmable Gate Array
- ASIC application-Specific Integrated Circuit
- An objective that the invention seeks to solve consists in realizing an interpolation function in a digital signal processing chain which is both inexpensive to implement, which allows it to be brought by a real time platform to a high output sampling frequency or even higher than the device operating frequency, while respecting spectral mask constraints.
- the invention relates to a signal interpolator produced in the form of a structured cascade of interpolators of different types.
- cascaded interpolation structures are known from the state of the art in order to interpolate a signal of a high rank, these structures are made up of interpolators of the same type, generally FIRs (acronym English for Finite Impulse Response or finite response filter), which can cause problems especially for the last stages where the length of the filters depends on the sampling frequency and the desired spectral purity.
- the invention starts from the principle that the cost of implementing the interpolation stages increases with the sampling frequency, and proposes to use interpolators whose complexity decreases with the wire of the interpolation.
- the interpolation reports of the different stages take account of the spectral properties of the stage which follows them in order to limit their complexity and to respect a constraining spectral mask.
- the invention describes an interpolator, for the interpolation by a ratio n of the sampling frequency of a signal called the input signal.
- the interpolator according to the invention successively comprises: a first interpolation stage comprising an oversampler configured to oversample the input signal of a ratio 3 ⁇ 4, n x being a submultiple of n, and a filter for filtering the oversampled signal, and
- a second interpolation stage comprising a linear interpolator configured to interpolate by a ratio n 2 the signal from the first interpolation stage, n 2 being a submultiple of n, and
- a third interpolation stage comprising a blocking interpolator configured to interpolate by a ratio n 3 the signal from the second interpolation stage, n 3 being a sub-multiple of n,
- the filter used by the first interpolation stage is a filter Fl R or a filter 11 R (English acronym for Infinity Impulse Response, or infinite impulse response).
- the linear interpolator of the second interpolation stage is configured to perform a linear interpolation equivalent to the oversampling of the signal from the first interpolation stage of a ratio n 2 by insertion of samples damaged then by the filtering of said oversampled signal by a filter having a frequency response in (sin (7r. fe 2 ) / (p. / e 2 )) 2 , with fe 2 the sampling frequency of the signal at the output of the second interpolation stage, said frequency response in (sin (7r. fe 2 ) / (p.
- each of these frequency bands has a width greater than the useful band of the input signal.
- linearly interpolating a signal amounts to oversampling it by inserting harmful samples, then filtering it by a filter whose frequency response is in (sin (7r. Fe 2 ) / (. Fe 2 )) 2 .
- the oversampling carried out by the second interpolation stage naturally creates n 2 periodic replicas of the signal spectrum from the first interpolation stage.
- the frequency response in (sin (. Fe 2 ) / (.fe 2 )) 2 includes (n 2 - 1) periodic zeros (infinite theoretical attenuation points) located at the level of the periodic replicas of the spectrum of the oversampled signal. Around each zero is a frequency band in which the attenuation is greater than a given minimum attenuation.
- the interpolation ratios of the first two interpolation stages are chosen so that each of the frequency bands has a width greater than the useful band of the input signal.
- the replicas of the useful signal due to the oversampling of a ratio n 2 in the linear interpolator are attenuated by a guaranteed minimum level.
- the ratio between the power of the useful signal replicas due to the oversampling of a ratio n 2 in the linear interpolator at the output of the equivalent filter whose frequency response is in (sin (.fe 2 ) / (. fe 2 )) 2 and the power of these same replicas at the input of the filter is less than a given ratio in all the frequency bands mentioned above.
- the blocking interpolator of the third interpolation stage is configured to perform a blocking interpolation, equivalent to the oversampling of the signal from the second interpolation stage of a ratio n 3 by insertion. of harmful samples then to the filtering of said oversampled signal by a filter having a frequency response in sin (n. fe 3 / (n. fe 3 , with fe 3 the sampling frequency of the signal at the output of the third stage of interpolation, said frequency response sin (n.fe 3 /(n.fe 3 having (n 3 - 1) periodic zeros around each of which is a frequency band whose attenuation is greater than a given minimum level.
- the interpolator is configured so that each of these frequency bands has a width greater than the useful band of the input signal. Indeed, interpolating by blocking a signal amounts to oversampling it by inserting harmful samples, then filtering it by a filter whose frequency response is in sin (n. Fe 3 / (n. Fe 3. The over- sampling performed by the third interpolation stage naturally creates n 3 periodic replicas of the spectrum of the signal from the second interpolation stage. The frequency response is in sm (n. fe 3 / (n. fe 3 includes (n 3 - 1 ) zeros (infinite theoretical attenuation points) which are located at the level of periodic replicas of the spectrum of the oversampled signal.
- each zero is a frequency band in which the attenuation is greater than a given minimum attenuation.
- interpolation ratios of the three stages of the interpolator are chosen so that each of these frequency bands has a width greater than or equal to the useful band of the input signal.
- l useful due to oversampling of a ratio n 3 in the blocking interpolator are attenuated by a guaranteed minimum level.
- the ratio between the power of the useful signal replicas due to the oversampling of a ratio n 3 in the linear interpolator at the output of the equivalent filter whose frequency response is in sin (n. Fe 3 / (n. fe 3 and the power of these same replicas at the input of the filter is less than a ratio given in all the frequency bands mentioned above.
- the interpolation ratio of at least one interpolation stage is a power of two, which gives the possibility of making the calculations as parallel as possible.
- the invention also relates to a method of interpolation by a ratio n of the sampling frequency of a signal called the input signal.
- the method successively comprises: a first interpolation step comprising the oversampling of said input signal by a ratio 3 ⁇ 4, where is a submultiple of n, and the filtering of the oversampled signal, and a second interpolation step comprising the linear interpolation of the signal resulting from the first interpolation step by a ratio n 2 , where n 2 is a submultiple of n, and a third interpolation step by signal blocking interpolator resulting from the second interpolation step by a ratio n 3 , where n 3 is a sub-multiple of n,
- the invention relates to a method for dimensioning an interpolator such as that described above.
- the dimensioning of the interpolator includes:
- a step of determining the interpolation ratio n 2 of the second stage of the interpolator This determination is made from a useful bandwidth of the signal to be transmitted and from a minimum attenuation of replicas of the signal entering the third interpolation stage due to the interpolation of a ratio n 3 , and
- Figure 1 shows an interpolator according to two embodiments of the invention
- FIG. 2 represents, by way of example, the normalized frequency response equivalent to a blocking interpolator interpolating the signal of a ratio 8;
- FIG. 3 represents, by way of example, the normalized frequency response equivalent to a linear interpolator interpolating the signal of a ratio 8;
- FIG. 4 represents three zoom levels of the normalized frequency response of a signal interpolated by an interpolator according to an embodiment of the invention
- Figure 5 shows an embodiment of a device for modulating two signals having a different sampling frequency comprising two interpolators according to embodiments of the invention
- Figure 6 shows the steps of a signal interpolation method according to the invention
- Figure 7 shows the steps of a method for dimensioning an interpolator according to the invention.
- FIG. 1 represents an interpolator according to two embodiments of the invention.
- the interpolator according to the invention comprises a first conventional interpolation stage 101, that is to say providing oversampling of the input signal by the insertion of (3 ⁇ 4 - 1) zeros between each sample of this signal, n x being the oversampling ratio of the first stage of the interpolator.
- the sampling frequency after oversampling being relatively low, a II R filter can be used in the case where the output frequency is compatible with the clock frequency of the digital component used.
- an FIR filter proves to be advantageous.
- the filtering interpolation technique makes it possible to control the spectral purity and to optimize the exploitation of the useful band of the original signal.
- the transition band of the filter is very narrow, which leads to a filter order that is too high and therefore too complex to implement (in the case of a low-pass filter, the transition band is the area between the end of the pass band and the start of the rejected band).
- the interpolation ratio n x must therefore be chosen as low as possible. It must also take into account the usable frequency domain of the next stage, as detailed below.
- the interpolator according to the invention also comprises a second interpolation stage 102 in the form of a linear interpolator. This is one of the simplest interpolation techniques, which consists in calculating the intermediate samples on a straight line which passes through two adjacent samples. We sometimes speak of "blocker of order 1 over n cycles", but this term is not completely exact because there is no blocking of the signal strictly speaking.
- the second interpolation stage 102 performs the interpolation of the signal from the first interpolation stage by a ratio n 2 .
- the linear interpolator can be produced very simply, by calculating the half-sum of the adjacent samples on N successive layers, until obtaining the (n 2 - 1) intermediate layers.
- the samples i and i + 1 correspond to the samples n 2 i and n 2 (i + 1) at the output sampling frequency. Thereafter, these output samples will be named m (0) and m (n 2 ).
- the calculation of the intermediate samples is as follows:
- linear interpolator The implementation complexity of a linear interpolator is lower than that of the so-called "classic" interpolator of the first stage, which allows it to be implemented at higher sampling frequencies.
- structure of the linear interpolator in particular when n 2 is a power of 2, is highly parallelizable.
- Such an interpolator is therefore particularly suitable for the generation and interpolation of a signal in real time, and can make it possible to generate an output signal from the second interpolation stage at a sampling frequency greater than the maximum operating frequency. of the component on which the interpolator is implemented.
- the interpolation ratio n 2 is chosen to be as low as possible while respecting the usable frequency domain of the third stage.
- the interpolation ratio n 3 is as large as possible, the third stage interpolator being the one whose implementation is the least complex.
- the spectral performances of the linear interpolation are very weak and do not allow to maximize the use of the band of the original signal, this is why such an interpolation cannot be used by the first stage of the interpolator.
- the interpolator comprises only the first stage 101 of interpolation by oversampling and filtering, and the second stage 102 of linear interpolation.
- h h 1 ⁇ n 2 .
- the interpolator further comprises a third interpolation stage 103, making it possible to interpolate the signal leaving the second interpolation stage by a ratio n 3 .
- the blocking interpolator of the third stage 103 performs an interpolation equivalent to the oversampling of the signal of a ratio n 3 by the insertion of n 3 1 samples damaged between each sample, then filtering it by an FIR filter comprising n 3 coefficients equal to 1.
- Oversampling in a ratio n 3 naturally generates (n 3 - 1). replicas of the signal entering the blocking interpolator. These (n 3 - 1). replicas have a high power level over a bandwidth which corresponds to the width of the useful signal to be interpolated. It is therefore necessary that the filtering of these replicas strongly attenuates the (n 3 - 1). aftershocks.
- the usable band of the signal entering the blocking interpolator should be limited as a function of the attenuation provided by the sin (f) / (f) function around its zeros, so that periodic spectrum replicas linked to oversampling by inserting zeros do not exceed a given maximum level.
- n 3 is greater than 8
- the variations in the template of the normalized sin (f) / (f) function are negligible.
- the width of the usable frequency band of the signal remains stable for values of n 3 greater than 8.
- the points 202 and 203 of FIG. 2 correspond to the limits of a frequency band 304 in which the attenuation is greater than 20dB around the first zero 201 of the frequency response in sin (7r /) / (7r /).
- the threshold value of 20dB is given here as an example.
- the relative bandwidth of the useful signal usable with a blocking interpolator is therefore low (less than 1% of the frequency band of the blocker output signal).
- it is sufficient with the proposed architecture because the first two interpolation stages make it possible to limit the ratio of the usable band of the signal to be interpolated to the sampling frequency of the third interpolation stage to the maximum ratio authorized by this stage. for the spectral purity chosen.
- the very low attenuation around the useful spectrum makes it particularly suitable for implementation as the last stage of a high-ranking interpolator.
- the second stage linear interpolator 102 performs an interpolation equivalent to oversampling the incoming signal by a ratio n 2 by inserting (n 2 - 1) harmful samples between each sample, then filtering it by an FIR filter comprising ( 2 n 2 - 1) coefficients in triangle. Oversampling in a ratio n 2 naturally generates (n 2 - 1) replicas of the signal entering the linear interpolator. These (n 2 - 1). replicas have a high power level over a bandwidth which corresponds to the width of the useful signal to be interpolated. It is therefore necessary that the filtering of these replicas strongly attenuates these (n 2 - 1). aftershocks.
- the impulse response in triangle corresponds to the convolution of two identical rectangles of n 2 points.
- the points 302 and 303 in FIG. 3 correspond to the limits of a frequency band 304 in which the attenuation is greater than 40dB around the first zero 301 of the frequency response in (sin (7r /) / (7r /)) 2 .
- the threshold value of 40dB is given here as an example.
- n 2 8
- the first interpolation stage is dimensioned to limit the ratio of the useful signal band to the sampling frequency fe 2 to the maximum ratio authorized by the second linear interpolation stage for the spectral purity chosen.
- the cascaded interpolator according to the invention therefore allows the implementation at low cost of a high-ranking interpolator on logic components (for example an FPGA), using stages of decreasing complexity and highly parallelizable, which facilitate its implementation. works in real time at high speed.
- the interpolator according to the invention has the following characteristics: - a high integer and factorizable interpolation rank (preferably of the form 2 N ),
- a filter which can be a Fl R or IIR filter
- the interpolation ratio of each stage is determined to control the spectral purity taking into account the ratio of the usable band to the sampling frequency of the following stage.
- a first embodiment presents a high-rank interpolator (4096), comprising three cascaded interpolation stages.
- An aim of the first interpolation stage is to raise the sampling frequency to the minimum value making it possible not to exceed the bandwidth usable by the second linear interpolation stage.
- the useful band of the signal must be less than 5% of relative band tolerated by the next stage of linear interpolation.
- Fpass must be less than or equal to 0.05% fe.
- the value of%, as well as the values of Fpass and Fstop make it possible to determine the size of the filter of the first interpolation stage, according to means known to those skilled in the art.
- a filter can be produced for example with 80 coefficients.
- interpolation stage 102 of linear interpolator type:
- the second stage of linear interpolation increases the sampling frequency to the value minimum so as not to exceed the 0.3% of relative band tolerated by the final stage of interpolation by blocking interpolator.
- the useful band Fpass of the signal to be interpolated must be less than or equal to 0.003%% fe, or n 2 16.7.
- the interpolator proposed in this embodiment therefore meets all the requirements, and can be implemented at low cost in a digital component.
- the use of an FIR in the first interpolation stage does not pose any implementation problems since the output sampling frequency of this stage is low.
- the complexity of the first stage of the interpolator according to the invention is divided by a ratio n 2 n s thanks to the presence of the next two floors. So for the same strip of transition of the filter and the same attenuation, the order of the filter used, that is to say its number of coefficients, is divided approximately in the same ratio.
- FIG. 4 represents three zoom levels of the normalized frequency response of an interpolator such as that described above, of rank 4096.
- the value 1 corresponds to / e.
- the representation 401 is the frequency response between the frequency 0 and the frequency Fe / 2 (2048 / e).
- the periodic replicas of the spectrum around points 256, 512, ..., 2048, which correspond to the oversampling by n 3 produced by the third interpolation stage, are well attenuated by more than 50dB after filtering by a filter with a frequency response in (sin (7r /) / (7r /)) 2 .
- the representation 402 is a zoom on the frequency response between the frequency 0 and the frequency 4 fe 1 (ie 32 / e).
- the periodic replicas of the spectrum around points 8, 16, ... 32 which correspond to the effects of oversampling by n x and n 2 of the first two interpolation stages, -are good attenuated by more than 50dB after filtering by a filter with a frequency response
- the representation 403 is a zoom on the frequency response between the frequency 0 and the frequency fe.
- the signal is only very slightly attenuated, while it is attenuated by more than 50dB in the rejected band. , which starts at 0.6 / e.
- a second embodiment presents an interpolator whose rank (32) is lower than that of the previous one.
- This interpolator only includes two cascaded interpolation stages.
- this value determines the size of the filter of the first interpolation stage, such as for example an FIR with 80 coefficients, which does not pose any particular implementation problems at the sampling frequency fe 1 .
- interpolation stage 102 of linear interpolator type:
- This stage increases the sampling frequency to the final value Fe. We therefore necessarily have n 2 4.
- a third embodiment presents a device intended to modulate a signal C sampled at the frequency Fe by the product of two modulating signals, a first signal at the frequency Fe / 4096 (modulating signal A) and a second at the frequency Fe / 32 (modulating signal B). Multiplying signal A by signal B and using the product of these two signals to modulate signal C first requires the harmonization of their respective sampling frequency.
- the embodiment described in FIG. 5 then corresponds to a combination of the embodiments presented in two and three stages presented previously.
- FIG. 5 One way of producing the product of the two modulating signals is shown in FIG. 5. It consists in bringing the modulating signal A to the frequency Fe / 4 by means of a three-stage interpolator such as that described previously for a ratio 4096 , and which comprises a first stage 501 of interpolation of a ratio 8 by oversampling and filtering, a second stage 502 of linear interpolation of a ratio 32 and a third stage 503 of interpolation by blocking interpolator.
- a three-stage interpolator such as that described previously for a ratio 4096 , and which comprises a first stage 501 of interpolation of a ratio 8 by oversampling and filtering, a second stage 502 of linear interpolation of a ratio 32 and a third stage 503 of interpolation by blocking interpolator.
- Such an interpolator meets all the requirements given above with regard to the preservation of the signal in its useful band and the attenuation of the periodic replicas of the spectrum generated by the oversampling of the
- the modulating signal B is also brought to the sampling frequency Fe / 4 by means of an oversampling of a ratio 8 and filtering.
- the product 505 of the two signals interpolated to Fe / 4 is then produced, and the resulting signal is brought to the sampling frequency Fe by a linear interpolation stage 506 of a ratio 4.
- Such an interpolation stage is possible because the assembly 504-506 relates to the case of the two-stage interpolator described above for a ratio 32.
- the useful band of the modulating signal A is much less than that of B: it therefore necessarily respects the constraint on the band d sampling usable by the linear interpolation stage 506.
- the product of the two modulating signals is used to modulate 507 the signal C at the frequency Fe.
- the invention also relates to a method of interpolation by a ratio n of the sampling frequency of a signal.
- This process performs the functions described by the device according to the invention, and all of the embodiments described in connection with the device can be applied mutatis mutandis to the process.
- Figure 6 shows the different stages of this process. He understands :
- a first step 601 of interpolating the input signal This interpolation is carried out by oversampling the input signal by a ratio, n x being a submultiple of n, then by filtering the oversampled signal, and
- a second step 602 of interpolation by linear interpolation of the signal resulting from the first step of interpolation has a ratio n 2 , n 2 being a submultiple of n.
- the method according to the invention may comprise only these two stages.
- the invention relates to a method for dimensioning an interpolator comprising several cascaded interpolation stages such as that shown in FIG. 1.
- the dimensioning method according to the invention comprises:
- n 2 a capacity of the second stage linear interpolator to attenuate the periodic replicas of the spectrum linked to the interpolation by the ratio n 2 , that is to say the size of the (n 2 - 1) frequency bands positioned around the frequencies fe,
- n 2 n / n.
- the dimensioning method according to the invention comprises two steps 701 and 702 described above, as well as an intermediate step 703 for determining the interpolation ratio n 2 of the second stage from:
- n 3 a capacity of the blocking interpolator of the third stage to attenuate the periodic replicas of the spectrum linked to the interpolation by the ratio n 3 , that is to say the width of the (n 3 - 1) frequency bands positioned around the frequencies fe 2 , 2 fe 2 , 3 fe 2 , ..., (n 3 - l) fe 2 guaranteeing a given attenuation (for example, choose n x and n 2 so that Fpass £ 0.003 ⁇ h 1 ⁇ H 2 ⁇ fe guarantees a minimum attenuation of 50dB of the replicas of the useful signal around the zeros of the blocking interpolator).
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- Theoretical Computer Science (AREA)
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Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1801161A FR3088156B1 (fr) | 2018-11-06 | 2018-11-06 | Interpolateur a rang eleve |
PCT/EP2019/079906 WO2020094506A1 (fr) | 2018-11-06 | 2019-10-31 | Interpolateur a rang eleve |
Publications (1)
Publication Number | Publication Date |
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EP3878098A1 true EP3878098A1 (fr) | 2021-09-15 |
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ID=65861315
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19794584.3A Pending EP3878098A1 (fr) | 2018-11-06 | 2019-10-31 | Interpolateur a rang eleve |
Country Status (3)
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EP (1) | EP3878098A1 (fr) |
FR (1) | FR3088156B1 (fr) |
WO (1) | WO2020094506A1 (fr) |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0052847B1 (fr) * | 1980-11-26 | 1985-07-17 | WILLI STUDER AG Fabrik für elektronische Apparate | Procédé et circuit pour la conversion de la fréquence d'échantillonnage d'une suite d'échantillons en évitant la conversion en un signal continu |
US5732107A (en) * | 1995-08-31 | 1998-03-24 | Northrop Grumman Corporation | Fir interpolator with zero order hold and fir-spline interpolation combination |
US7408485B1 (en) * | 2007-03-22 | 2008-08-05 | Texas Instruments Incorporated | Asynchronous sampling rate converter and method for audio DAC |
-
2018
- 2018-11-06 FR FR1801161A patent/FR3088156B1/fr active Active
-
2019
- 2019-10-31 WO PCT/EP2019/079906 patent/WO2020094506A1/fr unknown
- 2019-10-31 EP EP19794584.3A patent/EP3878098A1/fr active Pending
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Publication number | Publication date |
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FR3088156B1 (fr) | 2021-08-06 |
WO2020094506A1 (fr) | 2020-05-14 |
FR3088156A1 (fr) | 2020-05-08 |
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