DE102016108491B3 - Method for time-to-digital conversion with controlled temporal wavelet compression by means of a transmit wavelet and a controlled delay analysis wavelet - Google Patents

Abstract

The device carries out a method for determining the delay time of a first wavelet in a transmission path (I1). For this purpose, the first wavelet is sent into the transmission path at a time after a reference time. After passing through the transmission link, the delayed and typically deformed wavelet is scalar multiplied by a second wavelet. The result is compared with a reference value. At a cutting time (ts), the scalar product value intersects the reference value. Depending on this cutting time (ts) with respect to the reference time, the delay of the first and / or second wavelet is regulated with respect to the reference time. An amplitude control does not take place.

Description

preamble

The invention is directed to a method for converting a time delay (.DELTA.t) of a receiver output signal (S0) against a delayed transmission signal (S5d), the delayed transmission signal (S5d) in a transmission path (I1) of any physical nature in the conversion to the receiver output signal (S0) has learned.

General introduction

In many applications it is necessary to determine delay times of a signal relative to a transmitted signal. Such applications relate, for example, to the propagation time of electromagnetic waves, the transit time of sound waves, the time of flight of particles, reaction times in chemistry, disintegration times in particle physics, etc.

These delay times are typically to be further processed in digital data processing systems.

Against this background, the digitizing determination of such delay times is a fundamental problem of circuit technology.

State of the art

• 1. Erzeugen des digitalen Sendesignals und Einspeisung in die Übertragungsstrecke (I1) und Entnehmen des Empfängerausgangssignals aus der Übertragungsstrecke;
• 2. Bildung eines amplitudenwertdiskretten Ausgangssignals, dass das Empfängereingangssignal repräsentiert;
• 3. Vergleich des so gebildeten amplitudenwertdiskretten Ausgangssignals mit dem digitalen Sendesignal und Ausregelung einer Amplitudendifferenz zu Null.

Numerous methods of delta-sigma conversion of signal amplitudes are known from the literature. Common to all is that they have an amplitude controlled control loop. This amplitude is very much affected by noise and quantization errors for small deviations, which limits the resolution. If the delay of an analog receiver output signal compared to a digital transmission signal to be determined, the analog receiver output signal is summed with a negative feedback analog feedback signal to an analog filter input signal. The analog filter input signal indicates the weighted difference between the amplitude discrete output signal and the analog receiver output signal. The aim in the prior art is to control this deviation to zero. Therefore, the analog filter input signal is integrated with the aid of a first filter in the simplest case to the analog filter output signal. More complicated filter algorithms are conceivable. The analog filter output signal is then converted to an amplitude value discrete output signal. This amplitude value discrete output signal is then multiplied by an analog factor to the analog feedback signal and fed back to the control loop. In order to determine the delay between the thus amplitude value discrete output signal and the digital transmission signal, these are then compared with each other in a digital manner. The determination of the delay in a transmission path (I1) thus takes place in the three independent steps

• 1. generating the digital transmission signal and feeding into the transmission path (I1) and removing the receiver output signal from the transmission path;
• 2. forming an amplitude value discrete output signal representative of the receiver input signal;
• 3. Comparison of the thus formed amplitude value discrete output signal with the digital transmission signal and compensation of an amplitude difference to zero.

Each of these three stages results in processing errors in determining a digital value representing the delay in the transmission link.

Such an amplitude value discrete device is known for example from EP 2 924 460 A1 known. In the method disclosed therein, the amplitude-wise proportion of the basic wavelets on an input signal is determined by scalar product formation, which can be realized by multiplication and subsequent low-pass filtering. In a second step, the thus determined amplitude component values of the respective basic wavelets are multiplied by these basic wavelets, multiplied by minus 1 and mixed together to form a compensation signal which controls a compensation transmitter which is also incorporated into the receiver EP 2 924 460 A1 irradiates.

If the control loop is stable, the individual amplitude values of the respective base wavelets reflect the measurement result as measured value vector. Experiments have shown that the inventive method described below the method and apparatus of EP 2 924 460 A1 is superior and can achieve at least an order of magnitude higher resolution.

Object of the invention

The invention is therefore based on the object to provide a solution which reduces the above disadvantages of the prior art in the form of occurring process errors.

This object is achieved by a method according to claim 1.

Solution of the problem of the invention

• 1. Erzeugen des digitalen Sendesignals und Einspeisung in die Übertragungsstrecke (I1) und Entnehmen des Empfängerausgangssignals aus der Übertragungsstrecke;
• 2. Bildung und ZEITLICHE Ausregelung eines zeitkontinuierlichen, wertdiskreten Verzögerungswertsignals gegenüber dem Sendesignal, das einen Schnittpunkt des Filterausgangssignals mit einem Referenzwert repräsentiert, wobei das zeitkontinuierliche, wertdiskrete Verzögerungswertsignal die Verzögerungszeit repräsentiert.

According to the invention, it has been recognized that performing the temporal digitization in a single step reduces the sequence of the steps to be performed to the following sequence:

• 1. generating the digital transmission signal and feeding into the transmission path (I1) and removing the receiver output signal from the transmission path;
• 2. Forming and Timing a continuous-time, discrete-value delay value signal with respect to the transmission signal, which represents an intersection of the filter output signal with a reference value, wherein the time-continuous, discrete-value delay value signal represents the delay time.

An amplitude discretization by regulation of the amplitude of a filter input signal thus explicitly does not take place in contrast to the prior art. In contrast to the prior art, neither an amplitude nor gains or amplitudes of generator output signals used in the control loop nor the amplitude of the transmission signal are regulated. The aim of the control, in contrast to the prior art, is thus no longer to correct the filter input signal so that the amplitude values coincide, but the temporal intersection of the filter input signal with a first constant amplitude value coincides with the time intercept of the receiver input signal with a second amplitude value.

These first and second amplitude values are typically but not necessarily zero and equal.

The task of converting a time delay (.DELTA.t) of the receiver output signal (S0) against a delayed transmission signal (S5d), the delayed transmission signal (S5d) in a transmission path (I1) of any physical nature in the conversion to the receiver output signal (S0) has learned , is achieved according to the invention concretely by the following steps: First, the delayed transmission signal (S5d) is generated on the basis of a first temporal wavelet (WL1). In each time segment (T _s ) in which a wavelet is generated, this wavelet has a first temporal base point (t ₀ ). This base point (t ₀ ) is used below as a time reference point within a time period (T _s ). The time segments (T _s ) preferably do not overlap. Secondly, the delayed transmission signal (S5d) thus generated is now fed into said transmission path (I1). It passes through the transmission path (I1) and undergoes a conversion into the receiver output signal (S0). In fact, typically at the end of the transmission path (I1) there is a receiver which generates this receiver output signal (S0). For the problem described here, it is irrelevant which nature is the transmission link (I1), the transmitter or the receiver. Third, the generation of a first wavelet signal (WS1) is based on a second wavelet (WL2). This second wavelet (WL2) is typically not identical to the first wavelet (WL1) and typically has a different, second time base point (t ₀ + t _v ) in at least the relevant time period. Typically, it is provided with a first delay time (t _v ) from the first temporal base point (t ₀ ) of the first wavelet (WL1) in the time segment. Fourth, the formation of a temporal scalar product signal (S8) is followed by scalar product formation between the receiver output signal (S0) and the first wavelet signal (WS1). The nature of the dot product is the subject of further embodiments of the invention. The fifth is followed by the formation of a continuous-time, discrete-value delay value signal (S9) by comparing the value of the scalar product signal (S8) with a first reference value (Ref) and changing the value of the time-continuous, discrete-value delay value signal (S9). This is preferably done in a comparator when the value of the scalar product signal (S8) intersects a reference value (Ref) at a cutting time (t ₀ + t _s ) with respect to the first time base point (t ₀ )

Seventh follows a change of the first delay time (t _v ) as a function of the cutting time (t ₀ + t _s ). The change in the delay time (t _v ) thus depends on the time of the value change of the delay value signal (S9) and not on its amplitude value, which is the essential difference from the prior art. According to the invention, it has been recognized that such a point in time of the change in value of the delay value signal (S9) can be determined considerably more accurately than a specific amplitude. This improves the temporal resolution by at least a factor 10. Instead of regulating the second time base point (t ₀ + t _v ) of the second wavelet (WL2), for example, a regulation of the first temporal base point (t ₀ + t _v ) of the first Wavelets (WL1) take place, in which case preferably the second wavelet (WL2) has a second time base point (t ₀ ) without delay (t _v ). Of course, these two regulatory systems can be mixed. Wavelets are characterized by the fact that they have a delay (t _v ) for the transformation and a signal compression (α). This corresponds to the phase (φ) and the frequency (ω) of the Fourier transformation. Accordingly, it is conceivable in a further variant, instead of the delay (t _v ), the first compression (α ₁ ) of the first wavelet (WL1) in the generation of the delayed transmission signal as a function of the time of the value change of To control the delay value signal (S9) or to control the second compression (α ₂ ) of the second wavelet (WL2) in response to the timing of the value change of the delay value signal (S9). Of course, these control methods can also be combined. The combination can also be done with the regulation of the delay. A combination of several wavelet signals (WS1, WS2) in corresponding paths is possible.

Advantage of the invention

As already mentioned, a control method based on a signal value change has a much higher temporal resolution than a method based on an amplitude value.

Description of the developments / embodiments of the invention

In a further embodiment of the invention, the error is further minimized. This is done by the formation of a correction signal (K1) as a function of the cutting time (t ₀ + t _s ). The next step is to form a corrected scalar product signal (S10) by adding the value of the correction signal (K1) to the value of the scalar product signal (S8). The filtering of the corrected scalar product signal (S10) then generates the filtered scalar product signal (S11). This is usually an integrator or a low pass filter. The filtered scalar product signal (S11) thus formed is then used instead of the scalar product signal (S8) to form the time-continuous, discrete-value delay value signal (S9).

This has the advantage that the resulting resolution error is further minimized.

One possible concrete realization of the scalar product formation comprises the formation of a filter input signal (S2) by multiplication of the receiver output signal (S0) and the first wavelet signal (WS1), and the subsequent filtering of the filter input signal (S2) to the scalar product signal (S8). This filtering is typically carried out as integration and / or low-pass filtering.

The wavelets are preferably certain requirements, but not mandatory. It is particularly preferred if the first wavelet (WL1) and the second wavelet (WL2) are chosen such that the value of the scalar product signal (S8) decreases monotonically or decreases monotonically or increases monotonically or increases strictly monotonically from the time delay (.DELTA.t) of the delayed transmission signal (S5d) in the transmission path (I1) to the receiver output signal (S0) depends. This should be the case at least in a predetermined range. The time delay (Δt) should be in a time interval whose time length is different from zero.

List of figures

1 shows the simplified schematic diagram of a device that performs the inventive method by controlling the second wavelet generator (WG2).

2 shows the simplified schematic diagram of a device that performs the inventive method by controlling the first wavelet generator (WG1).

3 shows the simplified schematic diagram of a device that performs the method according to the invention with reduced error by controlling the second wavelet generator (WG2).

4 shows the simplified schematic diagram of a device that executes the method according to the invention with reduced error by controlling the first wavelet generator (WG1).

5 shows 1 supplemented by a second wavelet analysis signal path.

6 shows 5 , where now two wavelet generators are controlled.

7 shows 5 , where now the wavelet generator of the transmitter and a wavelet generator of the receive path are controlled.

Description of the figures

Fig. 1

1 shows the simplified schematic diagram of a device that performs the inventive method. A first wavelet generator (WG1) generates the delayed transmission signal (S5d) on the basis of a first wavelet (WL1), which is not drawn. The delayed transmission signal (S5d) is fed to the transmission path (I1). There it experiences the delay (.DELTA.t) and appears at the output of the transmission path (I1) as a delayed receiver output signal (S0). A second wavelet generator (WG2) generates the first wavelet signal (WS1) on the basis of the second wavelet (WL2), which is not drawn. A first multiplier (M1) multiplies the first wavelet signal (WS1) by the receiver output signal (S0) to the filter input signal (S2). A first filter (F1) filters the filter input signal (S2) to the scalar product signal (S8). The first filter is preferably a low-pass filter or an integrator. A time-to-digital converter (TDC), typically a comparator, forms the time-continuous, discrete-value delay value signal (S9) by comparing the value of the scalar product signal (S8) with a first reference value (Ref) and changing the value of the continuous-time, discrete-value delay value signal (S9) if the value of the scalar product signal (S8) exceeds the reference value (Ref ) at a cutting time (t ₀ + t _s ) with respect to the first time base point (t ₀ ) intersects. A controller (CTR) controls the delay (t _v ) of the second wavelet (WL2) in the second wavelet generator (WG2) in dependence on the time of change of the value of the continuous-time, discrete-value delay value signal (S9).

The first wavelet generator (WG1) and the second wavelet generator (WG2) are started in this example via a synchronization signal (t _sy ), which respectively indicates the base time (t ₀ ).

In 2 the delay is controlled in the first wavelet generator (WG1).

In 3 A correction unit (KE) converts the time of the change of the value of the time-continuous value-discrete delay value signal (S9) into a correction signal (K1). A first summer (Σ1) adds the scalar product signal (S8) and the correction signal (K1) to the corrected scalar product signal (S10). A first filter (F1) filters the corrected scalar product signal (S10) into a filtered scalar product signal (S11). The second filter is preferably a low-pass filter or an integrator. This forms now instead of in 1 Scalar product signal (S8) used the input signal for the time-to-digital converter (TDC).

In 4 the delay is controlled in the first wavelet generator (WG1).

Fig. 5

5 equals to 1 with the difference that a third wavelet generator (WG3) generates a second wavelet signal (WS2) with the aid of a third wavelet (WL3). In the example of 5 this happens unregulated in synchronism with the other wavelet generators (WG1, WG2). This second wavelet signal (WS2) is multiplied again in a second multiplier (M1b) by the receiver output signal (S0) to form a second filter input signal (S2b). Another first filter (F1b) filters the second filter input signal (S2b) to a second scalar product pre-signal (S8b). The output signal of the first filter (F1) is here called the first scalar product pre-signal (S8a). This first scalar product advance signal (S8a) and the second scalar product advance signal (S8b) are summed by the second summer (Σ2) weighted to the scalar product signal (S8). The second summer (Σ2) may be identical to the first summer (Σ1). The exemplary representation of a possible realization here can be combined with the other implementation possibilities described above and others that correspond to the claims.

Fig. 6

6 equals to 5 with the difference that now the second wavelet generator (WG2) and the third wavelet generator (WG3) are regulated. The control can be carried out by different signals with different sensitivity of the wavelet generators with respect to these control signals, ie weighted. It is also conceivable that the control takes place with different time constants.

Fig. 7

7 equals to 5 with the difference that now the first wavelet generator (WG1) and the third wavelet generator (WG3) are regulated. The control can be carried out by different signals with different sensitivity of the wavelet generators with respect to these control signals, ie weighted. It is also conceivable that the control takes place with different time constants.

LIST OF REFERENCE NUMBERS

• α

  first temporal compression of a wavelet

  α ₁

  first temporal compression of the first wavelet (WL1)

  α ₂

  second temporal compression of the second wavelet (WL2)

  .delta.t

  Delay of the receiver output signal (S0) compared to the delayed transmission signal (S5d)

  CTR

  regulator

  F1

  first filter

  F1b

  another first filter

  F2

  second filter

  I1

  transmission path

  K1

  correction signal

  KE

  correction unit

  M1

  first multiplier

  M1b

  second multiplier

  ω

  frequency

  φ

  phase

  Ref

  reference value

  S0

  Receiver output

  S2

  Filter input signal

  S2b

  second filter input signal

  s5d

  delayed transmission signal

  S8

  Scalar product signal

  S8a

  first scalar product pre-signal

  S8b

  second scalar product pre-signal

  S9

  continuous-time, discrete-value delay value signal

  S10

  corrected scalar product signal

  S11

  filtered scalar product signal

  Σ1

  first summer

  Σ2

  second summer

  t ₀

  first temporal base point of the first wavelet (WL1) in regulating the delay time t _{v of} the second time base time (t ₀ + t _v ) of the second wavelet (WL2) or second time base point of the second wavelet (WL2) in regulating the delay time t _v of first temporal base time (t ₀ + t _v ) of the first wavelet (WL1)

  t ₀ + t _s

  Cutting time

  t ₀ + t _v

  first temporal base time point (t ₀ + t _v ) of the first wavelet (WL1) during control of the same or second temporal base time point (t ₀ + t _v ) of the second wavelet (WL2) when controlling the same

  t _sy

  synchronization signal

  t _v

  delay

  TDC

  Time-to-digital converter (typically a comparator)

  WG1

  first wavelet generator

  WG2

  second wavelet generator

  WG3

  third wavelet generator

  WL1

  first wavelet

  WL2

  second wavelet

  WS1

  first wavelet signal

  WS2

  second wavelet signal

  <WS1, S0>

  Scalar product between the first wavelet signal (WS1) and the receiver output signal (S0)

Claims (7)

Method for converting a time delay (Δt) of a receiver output signal (S0) with respect to a delayed transmission signal (S5d), which has received the delayed transmission signal (S5d) in a transmission path (I1) of any physical nature during the conversion to the receiver output signal (S0), comprising the steps of generating the delayed transmit signal (S5d) on the basis of a first temporal wavelet (WL1), with a first temporal base point (t ₀ ) of the first wavelet (WL1) and a first temporal compression (α ₁ ) of the first wavelet (WL1) in at least one relevant period of time; - feeding the delayed transmission signal (S5d) into the transmission path (I1) and converting the delayed transmission signal (S5d) into the receiver output signal (S0); Generating a first wavelet signal (WS1) on the basis of a second wavelet (WL2), with a second time base point (t ₀ + t _v ) of the second wavelet (WL2) in at least the relevant time segment with a first delay time (t _v ) , which may be zero, with respect to the first time base point (t ₀ ) and a second time compression (α ₂ ) of the second wavelet (WL2); - Forming a temporal scalar product signal (S8) by scalar product formation between the receiver output signal (S0) and the first wavelet signal (WS1); - Forming a time-continuous, discrete-value delay value signal (S9) by comparing the value of the Skalar product signal (S8) with a first reference value (Ref) and changing the value of the continuous-time, discrete-value delay value signal (S9), if the value of the scalar product signal (S8 ) intersects the reference value (Ref) at a cutting time (t ₀ + t _s ) with respect to the first time base point (t ₀ ); Change of the first temporal compression (α ₁ ) of the first wavelet (WL1) as a function of the cutting time (t ₀ + t _s ) and / or change of the second temporal compression (α ₂ ) of the second wavelet (WL 2) as a function of the cutting time ( t ₀ + t _s ); Method according to claim 1 comprising the additional steps - additional change of the first delay time (t _v ) as a function of the cutting time (t ₀ + t _s ). Method according to claim 1, comprising the additional steps - formation of a correction signal (K1) as a function of the cutting time (t ₀ + t _s ); - forming a corrected scalar product signal (S10) by adding the value of the correction signal (K1) to the value of the scalar product signal (S8); Filtering the corrected scalar product signal (S10) to the filtered scalar product signal (S11); - using the filtered scalar product signal (S11) instead of the scalar product signal (S8) to form the time-continuous, discrete-value delay value signal (S9); The method of claim 1, wherein the formation of a scalar product time signal (S8) by scalar product formation between the receiver output signal (S0) and the first wavelet signal (WS1) is accomplished by the steps of - forming a filter input signal (S2) by multiplying the receiver output signal (S0) and the first wavelet signal (WS1); - filtering the filter input signal (S2) to the scalar product signal (S8). The method of claim 4, wherein the filtering of the filter input signal (S2) to the scalar product signal (S8) comprises integration. The method of claim 3, wherein the filtering of the corrected scalar product signal (S10) to the filtered scalar product signal (S11) comprises integration. A method according to claim 1, wherein the first wavelet (WL1) and the second wavelet (WL2) are chosen so that the value of the scalar product signal (S8) decreases monotonically or decreases monotonically or increases monotonically or increases strictly monotonically from the time delay (.DELTA.t) of the delayed transmission signal (S5d) in the transmission path to the receiver output signal (S0), wherein the time delay (.DELTA.t) is in a time interval whose time length is different from zero.

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