Method and device for determining a temporal offset between signals at different signal inputs

Abstract

To determine a temporal offset (Δt) between a first signal (s1) at a first signal input (2) and a second signal (s0) at a second signal input (3), a first instantaneous value of a first constant signal track (12), which increases strictly monotonously in a first early signal partial period and falls to zero strictly monotonously in a first late signal partial period and which is the first signal (s1) or is generated therefrom, is multiplied by a second instantaneous value of a temporal derivation (22) of a second constant signal track (13), which increases strictly monotonously in a second early signal partial period and falls to zero strictly monotonously in a second late signal partial period and is the second signal (s0) or is generated therefrom. A signal product (24) is thus obtained. The signal product (24) is integrated over the time. A signal integral (15) is thus obtained which shows the temporal offset (Δt) of the first signal (s1) to the second signal (s0).

Description

[0001] Method and device for determining a time offset between signals at different signal inputs

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to a method and a device for determining a time offset between signals at different signal inputs.

[0004] In many technical fields, the synchronicity of signals transmitted over different signal transmission paths is important. For example, when high-speed data is transmitted in parallel over multiple lines, the synchronicity of the signals used to transmit the data over the individual lines must be significantly higher than the inverse of the frequency of the signals on the individual lines. Otherwise, the bits transmitted over the individual lines cannot be assigned to a specific byte or other specific packet of parallel transmitted data.

[0005] The same applies if several signals are transmitted over essentially the same line or signal transmission path but using different carrier signals that differ, for example, in terms of their frequency.

[0006] In many cases, it is not sufficient for a specific application to simply set the synchronicity or, more generally, the precise temporal sequence between different signals once, because the precise temporal sequence can be lost, be it due to different drift of individual signal generators, different influences on different signal transmission paths, dispersion of the signals transmitted by means of carrier signals of different frequencies depending on environmental influences, etc. Both for the initial setting of the precise temporal sequence and for checking and, if necessary, readjusting the precise temporal sequence, determining the temporal offset between the respective signals as a measure of the deviation from the desired synchronicity of the signals is of great interest, if not necessary, in order to be able to adjust the desired temporal sequence.

[0007] STATE OF THE ART

[0008] To determine a time offset between signals at different signal inputs, the times at which the signals arrive at the different signal inputs can be recorded and a difference between these times can be determined. To do this, a counter can be started at the time the earlier of the two signals arrives and stopped at the time the later of the two signals arrives. The counter reading then indicates the time offset. The direction of the offset is indicated by which signal started the counter. Alternatively, one signal can cause the counter to count up and the other signal to count down, so that the sign of the counter reading indicates the direction of the time offset. This known method uses discrete counter time units and is therefore not analogizable and therefore not generally applicable.So it reaches its limits when it comes to small time offsets.

[0009] WO 02 / 099 544 A1 discloses a controller for a physical device that observes a correlation between various measured signals and automatically learns from this to control the device. The controller has a first signal input for a first input signal indicating a measured state of the device, and signal processing devices that generate a control signal depending on the first input signal to maintain the device in a desired state. The controller has additional signal inputs for further input signals, which are additional measurements of the device or its environment.The signal processing means use a weighted average of results from different fixed impulse responses to each input signal to modify the control signal, and means to automatically condition the modifications depending on temporal cross-correlations observed between the other input signals and a temporal derivative of the control signal. A further development of the control known from WO 02 / 099 544 A1 emerges from Bernd Porr and Florentin Wörgötter's "Strongly Improved Stability and Faster Convergence of Temporal Sequence Learning by Using Input Correlations Only," Neural Computation, July 2006, DOI: 10.1162 / neco.2006.18.6.1380. Here, instead of temporal cross-correlations between the other input signals and the temporal derivative of the control signal, temporal correlations between temporal derivatives of the other input signals and the first input signal are calculated.The resulting result is used to modify the amplitude of the first input signal so that it can be used as a control signal. The timing of the signals is neither determined nor modified.

[0010] US 7627 031 B2 discloses a device and a method for adaptively introducing a compensating signal latency that is related to the signal latency of a data symbol decision circuit. To compensate for the signal latency between two signals of the data symbol decision circuit, a second input signal is delayed by a variable delay time as a function of a first latency-affected signal. The variable delay time is adjusted by controlling a variable delay element in the form of an interpolating mixer so that the signal latency is optimally compensated with the delayed signal. A control variable, which is a measure of the signal latency of the decision circuit, is used to correctly adjust the delay time. The control variable is determined by multiplying the first signal by the time derivative of the second signal and subsequently integrating the signal product over time.

[0011] OBJECT OF THE INVENTION

[0012] The invention is based on the object of demonstrating a method and a device for determining a time offset between signals at different signal inputs, which can also be implemented in analog form and are suitable for determining very small time offsets.

[0013] SOLUTION

[0014] The object of the invention is achieved by a method having the features of independent patent claim 1 and by a device having the features of independent patent claim 11. Preferred embodiments of the method according to the invention and the device according to the invention are defined in the dependent claims 2 to 10 and 12 and 13, respectively.

[0015] DESCRIPTION OF THE INVENTION

[0016] In a method according to the invention for determining a temporal offset between a first signal at a first signal input and a second signal at a second signal input, a first instantaneous value of a first continuous signal trace, which increases strictly monotonically in a first early signal sub-period and decreases strictly monotonically towards zero in a first late signal sub-period, is multiplied by a second instantaneous value of a temporal derivative of a second continuous signal trace, which increases strictly monotonically in a second early signal sub-period and decreases strictly monotonically towards zero in a second late signal sub-period, thereby obtaining a signal product. The signal product is integrated over time. This obtains a signal integral which indicates the temporal offset of the first signal from the second signal in terms of magnitude and sign.

[0017] The first signal input can be connected to a first signal transmission path, and the second signal input can be connected to a separate second signal transmission path. However, the first signal input and the second signal input can also be connected to a common signal transmission path via a signal branching, for example, based on the frequency of a carrier signal, i.e., via a so-called crossover network.

[0018] The first continuous signal trace can be directly the first signal at the first signal input or can be generated therefrom. The first signal trace can be generated, for example, by outputting a first signal curve with a predefined signal curve triggered by the arrival of the first signal at the first signal input. This decouples the signal curve of the first signal trace from the curve of the first signal. The first signal can then have any desired curve. However, if the first signal has a first continuous signal trace that increases strictly monotonically in a first early signal sub-period and decreases strictly monotonically to zero in a first late signal period, the first signal itself can be used as the first continuous signal trace. Preferably, the first continuous signal trace increases strictly monotonically from zero in the first early signal sub-period and decreases strictly monotonically back to zero in the first late signal period.The same applies to the second continuous signal trace. In particular, the second continuous signal trace can also be the second signal directly or be generated from it. If the second continuous signal trace is generated from the second signal in such a way that the arrival of the second signal at the second signal input triggers the output of a second signal curve with a predefined signal profile, the time derivative of the second continuous signal trace can be directly specified and triggered by the arrival of the second signal at the second signal input. In any case, the time derivative of the second continuous signal trace is positive in the second early signal sub-period, initially increasing until it falls again and then becomes negative in the second late signal period.

[0019] The signal integral obtained by the method according to the invention indicates the temporal offset of interest between the first signal and the second signal in magnitude and direction, specifically over small temporal offsets with a linear dependence. As will be explained below, the linear dependence can be adjusted so that the signal integral indicates the temporal offset with high resolution, i.e., with a significant change in the signal integral even with small changes in the offset.

[0020] To obtain this meaningful signal integral, it is sufficient to integrate the signal product with respect to the earlier of the two signals over an integration period that is at least as long as the signal trace to the earlier of the two signals. After that, the signal product is zero because one of its factors, i.e., the signal trace to the earlier of the two signals, and thus also its time derivative, has decayed to zero.

[0021] The beginning or arrival of the respective signal can be detected by comparing a signal level at the respective signal input with a threshold value, whereby the time at which the signal level exceeds the threshold value is defined as the beginning or arrival of the respective signal.

[0022] Preferably, the first signal curve that can be output to generate the first signal trace is a first double exponential curve. The second signal curve that is output to generate the second signal trace is preferably a second double exponential curve. The second double exponential curve can be identical to the first double exponential curve. If the derivative of the second continuous signal trace is output directly, in this embodiment this is the derivative of a second double exponential curve. In the method according to the invention, the first continuous signal trace and the second continuous signal trace, regardless of whether they are the first and second signals or are generated therefrom, can be identical to one another, i.e. in particular have identical early and late signal sub-periods and identical amplitudes. However, this is not critical for the function of the method according to the invention.The signal integral obtained according to the invention indicates the time offset of the first signal to the second signal even if the early signal sub-periods and / or the late signal sub-periods and / or the amplitudes of the signal traces are different.

[0023] In the method according to the invention, the first signal trace or the time derivative of the second signal trace can be delayed by a predetermined period of time before the first instantaneous value of the first continuous signal trace is multiplied by the second instantaneous value of the time derivative of the second continuous signal trace. In this way, a desired time offset between the first signal and the second signal can be specified at which the signal integral becomes zero. It is irrelevant whether the first signal trace is delayed directly, or first the first or second signal trace generated therefrom, or first the derivative of the second signal trace itself is delayed. If a positive time offset between the first signal and the second signal is desired, the first signal trace must be delayed; if a negative time offset between the first signal and the second signal is desired, the time derivative of the second signal trace must be delayed.

[0024] In order to specifically set the desired time offset between the first signal at the first signal input and the second signal at the second signal input, the signal integral can be made zero by acting on a first signal transmission path to the first signal input and / or on a first signal generator generating the first signal. In this procedure, the second signal is used as a reference to which the first signal is temporally adjusted. It is understood that acting on the first signal transmission path to the first signal input for the targeted setting of the desired time offset of the signals is particularly effective when the first signal transmission path only transmits the first signal and not also the second signal.In principle, however, it is also possible to create the desired time offset by influencing a common signal transmission path that also transmits the second signal, if the influence on the common signal transmission path has different effects on the signal propagation times of the two signals over the common signal transmission path. Specifically, with the method according to the invention, a first signal propagation time over the first signal transmission path can be varied by varying a first length of the first signal transmission path using a switchable delay. With the switchable delay, the first signal transmission path can be extended by different signal transmission segments.The signal propagation time over the first signal transmission path can also be influenced by a mechanical or thermal expansion of the first signal transmission path and / or a change in the temperature of a wired first signal transmission path.

[0025] The method according to the invention can be applied to both optical and electrical signals. In both cases, the signals can be digital data signals.

[0026] The method according to the invention can not only be used to determine the time offset between the first signal and the second signal and to compensate for it if necessary. At least one further time offset between a further signal at a further signal input and the second signal at the second signal input can also be determined and compensated for if necessary in basically the same way as the time offset between the first signal at the first signal input and the second signal at the second signal input. On this basis, identical or different desired time offsets to the second signal can be set for a large number of signals. In principle, however, it is also possible to determine any further time offset between the further signal and a signal other than the second signal and to eliminate it if necessary.In this way, desired time offsets between all signals can also be set, and in particular, synchronicity of all signals can be achieved.

[0027] An apparatus according to the invention for carrying out the method according to the invention has the first signal input, the second signal input, a first pulse signal generator connected to the first signal input, a second pulse signal generator connected to the second signal input, an integration period generator connected to the first pulse signal generator and the second pulse signal generator, and a signal integral generator which multiplies the first instantaneous value of the first continuous signal trace by the second instantaneous value of the time derivative of the second continuous signal trace, whereby the signal product is obtained, and which integrates the signal product over time, whereby the signal integral is obtained.

[0028] The first pulse signal generator compares the first signal level at the first signal input with the first threshold and detects the start of the first signal when the first signal level exceeds the first threshold. Correspondingly, the second pulse signal generator compares the second signal level at the second signal input with the second threshold and detects the second start of the second signal when the second signal level exceeds the second threshold. The integration interval generator generates the integration period after the start of the earlier of the two signals, whereby the integration period is at least as long as the earlier of the two signals. The signal integral obtained by the signal integral generator indicates the temporal offset of the first signal from the second signal in terms of magnitude and direction.

[0029] The device according to the invention can further comprise a first signal trace generator which generates the first signal trace by outputting the first signal curve from the first beginning, and a second signal trace generator which generates the second signal trace by outputting the second signal curve or directly its time derivative from the second beginning.

[0030] If the device according to the invention has an adjustable delay for the first signal track and / or for the time derivative of the second signal track, a desired time offset between the first signal and the second signal can be specified at which the signal integral becomes zero.

[0031] Furthermore, the device according to the invention can have a time offset setting device which makes the signal integral zero for the targeted setting of the desired time offset between the first signal and the second signal by acting on the first signal transmission path to the first signal input and / or on the first signal generator generating the first signal.

[0032] Advantageous developments of the invention will become apparent from the patent claims, the description, and the drawings. The advantages of features and combinations of features mentioned in the description are merely exemplary and may be effective alternatively or cumulatively, without necessarily achieving the advantages of embodiments according to the invention.

[0033] With regard to the disclosure content – ​​not the scope of protection – of the original application documents and the patent, the following applies: Further features can be found in the drawings – in particular the illustrated geometries and the relative dimensions of several components to one another, as well as their relative arrangement and operative connection. The combination of features of different embodiments of the invention or features of different patent claims is also possible, deviating from the chosen references of the patent claims, and is hereby encouraged. This also applies to features that are illustrated in separate drawings or mentioned in their description. These features can also be combined with features of different patent claims.Likewise, features listed in the patent claims may be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

[0034] The number of features mentioned in the patent claims and the description is to be understood as meaning that exactly this number or a greater number than the stated number is present, without the need for the explicit use of the adverb "at least." Thus, for example, if reference is made to a first signal transmission path, this is to be understood as meaning that exactly one first signal transmission path, two first signal transmission paths, or more first signal transmission paths are present. The features mentioned in the patent claims may be supplemented by further features or may be the only features present in the subject matter of the respective patent claim.

[0035] The reference symbols contained in the patent claims do not represent a limitation of the scope of the subject matter protected by the patent claims. They serve solely to make the patent claims easier to understand. BRIEF DESCRIPTION OF THE FIGURES

[0036] In the following, the invention is further explained and described with reference to preferred embodiments shown in the figures.

[0037] Fig. 1 is a block diagram of a first embodiment of the method and device according to the invention.

[0038] Fig. 2 shows a signal trace as it can be generated using the method according to the invention.

[0039] Fig. 3 shows an embodiment of a signal track generator of the device according to the invention, which generates the signal track according to Fig. 2.

[0040] Fig. 4 shows an embodiment of an integration period generator of the device according to the invention.

[0041] Fig. 5 illustrates the generation of an integration period by the integration period generator according to Fig. 4.

[0042] Fig. 6 illustrates the structure of a signal integral generator of the device according to the invention.

[0043] Fig. 7 is a plot of the signal integral obtained by the signal integral generator of Fig. 6 versus the time offset of a first signal relative to a second signal.

[0044] Fig. 8 illustrates the simultaneous coupling of a laser pulse as synchronous input signals into several optical fibers of an optical fiber as signal transmission paths with different signal propagation times.

[0045] Fig. 9 is a block diagram of a further embodiment of the method according to the invention and the device according to the invention for determining the time offsets between output signals at the end of the signal transmission paths according to Fig. 8. Fig. 10 illustrates a synchronization of the output signals at the outputs of the signal monitoring paths according to Fig. 8 based on the signal integrals obtained by the method according to the invention and the device according to the invention according to Fig. 9; and

[0046] Fig.11 shows the synchronization of ten originally asynchronous signals (left).

[0047] The synchronization curve is shown at the bottom right. Signals are synchronous when the time offset has reached zero. The control signals that generate the shift of the input signals to achieve the zero time offset are shown at the top right.

[0048] FIGURE DESCRIPTION

[0049] The device 1 illustrated in Fig. 1 has a first signal input 2 and a second signal input 3. A first pulse generator 4 is connected to the first signal input 2, and a second pulse generator 5 is connected to the second signal input 3. The pulse generators 4 and 5 compare a signal level present at the respective signal input 2 or 3 with a first or second threshold value and detect the start of a first signal Si arriving at the first signal input 2 and the start of a second signal So arriving at the second signal input by the respective signal level exceeding the threshold value. With the start of the respective signal Si or So, the pulse generators 4 and 5 output a pulse signal 6 or 7 at the signal input 2 or 3, respectively, which therefore indicates the time of the start with its rising edge.Both pulse generators 4 and 5 are connected here, on the one hand, to an integration period generator 8 and, on the other hand, to a first and second signal trace generator 10, 11, respectively. The integration period generator 8 generates an integration period 9. The signal trace generators 10 and 11 generate a first signal trace 12 and a second signal trace 13 by outputting a first and second signal curve starting from the beginning of the signal Si and So, respectively. The integration period generator 8 and the signal trace generators 10 and 11 are connected to a signal integral generator 14. This generates a signal integral 15 from the signal traces 12 and 13 using the integration period 9, which indicates a temporal offset of the first signal Si from the second signal So in terms of magnitude and direction. The signal traces 12 and 13 generated by the signal trace generators 10 and 11 are preferably double exponential curves 16, an example of which is shown in Fig. 2.From its beginning at time t = 0, the amplitude A(t) of the double exponential curves 16 is given by A(t) = exp (-at) - exp (-bt), where a is smaller than b. The double exponential curve 16 is a preferred special case of a continuous signal trace that increases strictly monotonically from zero in an early signal subperiod and decreases strictly monotonically back to zero in a late signal subperiod.

[0050] Fig. 3 illustrates a practical implementation of a signal trace generator 2 outputting a signal trace 12 in the form of a double exponential curve 16 according to Fig. 2. This filter filters the pulse signal 6 coming from the pulse generator 4 as a rectangular pulse with two different high-pass filters 17 and 18. The signal trace generator 2 then subtracts the pulse signal 6 filtered with the other high-pass filter 18 from the pulse signal 6 high-pass filtered with one high-pass filter 17 in order to generate the signal trace 12. The one high-pass filter 17 generates the summand exp(-at) and the other high-pass filter 18 generates the summand - exp(-bt) of the double exponential function A(t) = exp(-at) - exp(-bt).

[0051] Fig. 4 illustrates an embodiment of the integration period generator 8. An OR gate 19 passes the earlier of the pulse signals 6 and 7, which then triggers a retriggerable monostable multivibrator 20 with duration D. The monostable multivibrator 20 is retriggered with duration D by the later pulse signal 6 or 7.

[0052] Fig. 5 shows for an earlier pulse signal po and a later pulse signal pi of the two pulse signals 6, 7 the resulting integration period 9 from its starting time t s with the rising edge of the previous pulse signal po until its end time t e, which lies behind the rising edge of the later pulse signal pi by the duration D. The left-hand dashed line indicates the point in time at which the monostable multivibrator is triggered again by the rising edge of the later pulse signal pi and then remains high for the duration D, thus continuing the integration period 9. The monostable multivibrator can also be triggered simply, i.e. only by the earlier pulse signal po, and therefore does not have to be retriggerable. In any case, the choice of duration D must ensure that the integration period 9 is at least as long as the signal trace 12 or 13 that is generated for the earlier pulse signal po of the two pulse signals 6, 7. Accordingly, the duration D must be at least as long as the longer of the two signal tracks 12 and 13. Fig. 6 shows an embodiment of the signal integral generator 14. A differentiator 21 generates a time derivative 22 of the signal track 13 to the second signal So.A multiplier 23 multiplies the signal trace 12 to the first signal Si at the first signal input 2 by the derivative 22, resulting in a signal product 24. An integrator 25 integrates the signal product over the integration period 9, i.e., from t. s are e . This results in the signal integral 15 being obtained, which indicates the offset of the signal track 12 relative to the signal track 13 and thus of the first signal Si at the first signal input 2 relative to the second signal So at the second signal input 3.

[0053] Fig. 7 is a plot of the signal integral 15 against the time offset Δt of the signal trace 12 or the first signal Si compared to the signal trace 13 or the second signal So. If the signal trace 12 leads the signal trace 13, the signal integral 15 is positive because less of the signal trace 12 falls into the period in which the derivative 22 of the signal trace 13 is negative. Conversely, if the signal trace 12 leads, the signal integral 15 is negative because then less of the signal trace 12 falls into the time range in which the derivative 22 is positive. In between, the signal integral 15 has a zero crossing. At this zero crossing, the signal traces 12 and 13 and thus also the signals Si and So at the signal inputs 2 and 3 are synchronized. Around the zero crossing, the course of the signal integral 15 is linearly dependent on the time offset Δt.This range of linear dependence can be varied by the durations of the signal sub-periods of signal traces 12 and 13, i.e., for example, the factors a and b of the summands of the double exponential curve A(t) = exp(-at) - exp(-bt). If very small temporal offsets are to be resolved, higher factors must be selected, which result in shorter early and late signal sub-periods. However, larger temporal offsets Δt then lead outside the range of the linear dependence of the signal integral 15 on the offset Δt or even result in a signal integral 15 outside the range shown in Fig. 7, i.e., a signal integral of zero. With smaller factors a and b, the linear range of the linear dependence of the signal integral 15 on the offset Δt is broadened, but the gradient in the linear range decreases, which means a lower resolution of the temporal offset Δt due to changes in the signal integral 15.

[0054] The signal integral 15 can be used to control a time offset setting device for specifically setting a desired time offset between the first signal Si applied to the first signal input 2 and the second signal So applied to the second signal input 3, and in particular for synchronizing the first signal Si with the second signal So. When the signal integral 15 is positive, the time offset setting device delays the first signal Si at the first signal input 2; when the signal integral 15 is negative, the time offset setting device ensures a temporal advance of the first signal Si at the second signal input 2. The necessary degree of delay or advance of the first signal Si is indicated by the absolute value of the signal integral 15. When synchronizing the signals Si and So, a desired time offset of zero is set for the signals.In order to set a different desired time offset of the signals, the first signal track 12 or the time derivative 22 of the second signal track 13 is to be delayed by a corresponding period of time before the first instantaneous value of the first continuous signal track 12 is multiplied by the second instantaneous value of the time derivative 22 of the second signal track 13.

[0055] Fig. 8 illustrates the coupling of a laser pulse 26 as synchronous input signals 27 into ten parallel optical fibers 28 of a fiber optic 29. At the other end of the fiber optic 29, output signals 30 emerge from the optical fibers 28. These output signals have become temporally broader than the input signals 27 due to chromatic dispersion and are no longer synchronous due to manufacturing differences, different spatial routing, etc. of the individual optical fibers 28, but exhibit temporal offsets. The relevant temporal offsets are, for example, on the order of a few picoseconds and can be determined and then compensated for using the method according to the invention.

[0056] Since the still Gaussian output pulses 30 also qualify as signal traces which increase strictly monotonically from zero in an early signal sub-period and decrease strictly monotonically back to zero in a late signal sub-period, no signal traces need to be generated to determine the offsets of the output signals 30, but the output signals 30 themselves can be used as signal traces 12 and 13.

[0057] Fig. 9 shows a corresponding embodiment of the device 1 without signal track generators 10 and 11. The pulse signals 6 and 7 generated by the pulse generators 4 and 5 are used here by the integration period generator 8 only to generate the integration period 9. Otherwise, the first and second signals Si and So applied to the signal inputs 2 and 3 are fed directly to the signal integral generator 14 as signal tracks 12 and 13. This does not, of course, preclude the arrangement of filters in the signal inputs 2 and 3 which only allow the relevant output signals 30 according to Fig. 8 to pass through. Depending on the signal integral 15, which is determined in each case for an output signal 30 emerging from one of the optical fibers 28 and an output signal 30 serving as reference signal 31 emerging from an optical fiber 28 serving as reference line 32, the filter shown in Fig.10 schematically indicated time offset adjustment device 33 to the signal transmission paths 34 formed by the other optical fibers 28 in order to change the signal propagation times over these signal transmission paths 34 such that the synchronized output pulses 30' shown in Fig. 10 emerge from the individual optical fibers 28. This means that the aim of this embodiment is to set a desired time offset of the signals of exactly zero, which corresponds to their synchronization.

[0058] As a possible intervention by the time offset adjustment device 33 in the signal propagation time of the signal transmission paths 34, several hundred meters of optical fiber are wound into a coil 35, the temperature of which can be adjusted using a thermocouple 36. A temperature change of 1 degree results in a propagation time change of approximately 40 picoseconds per kilometer of length of the wound optical fiber 28. By adjusting the temperatures of the coils 35 using the thermocouples 36, differences between the signal propagation times of the signal transmission paths 34, ranging from a few picoseconds to several hundred picoseconds, can be compensated. The signal integral 15 specifies the required temperature change in terms of magnitude and direction.The success of the synchronization by the time offset adjustment device 33 can be checked upon arrival of the next output pulses 30 at the device 1 according to the invention by determining the remaining time offsets compared to the reference signal 31. Any remaining time offsets can then be compensated for. With an optimal relationship between the magnitude and direction of the signal integral 15 and the temperature change of the coils 35 caused by the time offset adjustment device 33, the synchronicity of the output pulses 30 can be achieved in one step. If the temperature changes are set somewhat too small, the method converges from one side to the synchronicity of the output pulses 30 after several steps. If the temperature change is too large, an overshoot occurs, i.e.to a change in the direction of the time offset, but if the gain is not too large, the method still converges to the synchronicity of the output pulses 30.

[0059] Fig. 11 shows on the left ten temporally offset Gaussian signals Sj, such as can arise in optical fibers, e.g. due to chromatic aberration. These signals Sj were fed into the inventive method as input signals, with the signal So, which was used as a reference for synchronization, being marked with a long dashed line. Two further signals Sj, one with a time offset of approximately -100 ps and another with a time offset of approximately +150 ps to the signal So, are highlighted as examples with short dashed lines. These ten signals Sj were repeated several thousand times and each fed into the inventive method, with them being shifted in time with each repetition due to the effect of the time offset setting with the aim of achieving an offset of zero. The time shift of the signals Sj is shown bottom right, with zero on the y-axis corresponding to the time of the signal So. So you can see here, for example.B. how the signal originally shifted by +150 ps gradually loses offset and is synchronous with the signal So after approximately 3,500 repetitions, i.e. a temporal offset of zero is reached. With a signal repetition rate in the range of, for example, 1 GHz, this would correspond to a time of approximately 3.5 ps until complete synchronicity. The same applies to all other signals which, however, become synchronous with the signal So earlier due to their lower original offset. Signals that are too early are delayed so that the negative y-values ​​decrease, while those that are too late are accelerated so that the positive values ​​decrease. For this purpose, the signal integrals 15 generated by the method according to the invention are used as control signals, see Fig. 11 top right. These control signals indicate the respective proportional reduction in the offset.For the signal on the far right, whose original offset was +150 ps, ​​the resulting signal integral is 15, which initially lies only slightly below zero due to the slight temporal overlap with the signal So, then becomes increasingly negative before rising back to zero. It can be seen that the control signal becomes zero precisely when the corresponding signal has become synchronous with the signal So.

[0060] LIST OF REFERENCE SYMBOLS

[0061] device

[0062] First signal input

[0063] Second signal input

[0064] First pulse signal generator

[0065] Second pulse signal generator

[0066] First pulse signal

[0067] Second pulse signal

[0068] Integration period generator

[0069] Integration period

[0070] First signal trace generator

[0071] Second signal track generator

[0072] First signal track

[0073] Second signal track

[0074] Signal integral generator

[0075] Signal integral

[0076] Double exponential curve

[0077] High-pass filter

[0078] High-pass filter

[0079] OR gate

[0080] Monostable multivibrator

[0081] Differentiator

[0082] Derivation

[0083] multiplier

[0084] Signal product

[0085] Integrator

[0086] laser pulse

[0087] Input signal

[0088] optical fiber

[0089] light guide

[0090] Output signal

[0091] Reference signal

[0092] Reference line 33 Time offset setting device

[0093] 34 Signal transmission path

[0094] 35 coil

[0095] 36 thermocouple

[0096] Si First Signal

[0097] So Second Signal

[0098] Po Previous pulse signal

[0099] Pi Later pulse signal

[0100] D Duration t s Start time te End time

[0101] At Time offset

[0102] A(t) Amplitude of the double exponential curve 16

Claims

PATENT CLAIMS 1. A method for determining a time offset (Δt) between a first signal (si) at a first signal input (2) and a second signal (so) at a second signal input (3), wherein a first instantaneous value of a first continuous signal trace (12), which increases strictly monotonically in a first early signal sub-period and decreases strictly monotonically towards zero in a first late signal sub-period and which is the first signal (si) or is generated therefrom, is multiplied by a second instantaneous value of a time derivative (22) of a second continuous signal trace (13), which increases strictly monotonically in a second early signal sub-period and decreases strictly monotonically towards zero in a second late signal sub-period and which is the second signal (so) or is generated therefrom, thereby obtaining a signal product (24), and wherein the signal product (24) is integrated over time, thereby obtaining a signal integral (15).which indicates the time offset (At) of the first signal (si) to the second signal (so).

2. Method according to claim 1, characterized in that the signal product (24) is integrated over an integration period (9) after the earlier of the two signals (po), wherein the integration period (9) is at least as long as the signal trace (12 or 13) to the earlier of the two signals (po).

3. Method according to claim 1 or 2, characterized in that a first signal level at the first signal input (2) is compared with a first threshold value and in that a first start of the first signal (si) is detected by the first signal level exceeding the first threshold value, and / or in that a second signal level at the second signal input (3) is compared with a second threshold value and a second start of the second signal (so) is detected by the second signal level exceeding the second threshold value.

4. Method according to claim 3, characterized in that the first signal trace (12) is generated from the first signal (si) by a first signal curve from the first beginning is output, and / or that the second signal track (13) is generated from the second signal (so) by outputting a second signal curve from the second beginning.

5. The method according to claim 4, characterized in that the first signal curve is a first double exponential curve (16) and / or that the second signal curve is a second double exponential curve (16).

6. Method according to one of the preceding claims, characterized in that the first signal track (12) or the time derivative (22) of the second signal track (13) is delayed by a predetermined period of time before the first instantaneous value of the first signal track (12) is multiplied by the second instantaneous value of the time derivative (22) of the second signal track (13).

7. Method according to one of the preceding claims, characterized in that the signal integral (15) is made zero for the targeted setting of a desired time offset between the first signal (si) and the second signal (so) by acting on a first signal transmission path (34) to the first signal input (2) and / or on a first signal generator generating the first signal (si).

8. The method according to claim 7, characterized in that a first signal propagation time is varied over the first signal transmission path (34), wherein optionally a first length of the first signal transmission path (34) is varied by means of a switchable delay.

9. Method according to one of the preceding claims, characterized in that the first signal (si) and the second signal (so) are optical or electrical signals.

10. Method according to one of the preceding claims, characterized in that the first signal (si) and the second signal (so) are digital data signals.

11. Method according to one of the preceding claims, characterized in that a further time offset between a third signal at a third signal input and the second signal (so) at the second signal input (3) is determined.

12. Device for carrying out the method according to claim 3 as far as it is dependent on claim 2 or for carrying out the method according to one of claims 4 to 10 as far as it is dependent on claim 2 and claim 3, with the first signal input (2), the second signal input (3), a first pulse signal generator (4) connected to the first signal input (2), which compares the first signal level at the first signal input with the first threshold value and detects the first start of the first signal (si) by the first signal level exceeding the first threshold value, a second pulse signal generator (5) connected to the second signal input (3), which compares the second signal level at the second signal input (3) with the second threshold value and detects the second start of the second signal (so) by the second signal level exceeding the second threshold value,an integration period generator (8) connected to the first pulse signal generator (4) and the second pulse signal generator (5), which generates the integration period (9) after the beginning of the earlier of the two signals (so or Si), wherein the integration period (9) is at least as long as the signal trace (12 or 13) for the earlier of the two signals (so or Si), and a signal integral generator (14) which multiplies the first instantaneous value of the first continuous signal trace (12), which increases strictly monotonically in the first early signal sub-period and decreases strictly monotonically in the first late signal sub-period and which is the first signal (si) or derived therefrom, by the second instantaneous value of the time derivative (22) of the second continuous signal trace (13), which increases strictly monotonically in a second early signal sub-period and decreases strictly monotonically in a second late signal sub-period and which is the second signal (so) or derived therefrom,wherein a signal product (24) is obtained, and the signal product (24) is integrated over time, whereby a signal integral (15) is obtained which indicates the time offset (At) of the first signal (si) to the second signal (so).

13. Device according to claim 12 for carrying out the method according to claim 4, characterized by a first signal trace generator (4) which generates the first signal trace (12) by outputting the first signal curve from the first beginning, and a second signal trace generator (5) which generates the second signal trace (13) by outputting the second signal curve or its time derivative (22) from the second beginning.

14. Device according to claim 12 or 13 for carrying out the method according to claim 6, characterized by an adjustable delay for the first signal track (12) and / or for the time derivative (22) of the second signal track (13).

15. Device according to claim 12, 13 or 14 for carrying out the method according to claim 7, characterized by a time offset setting device (33) which makes the signal integral (15) zero for the targeted setting of a desired time offset between the first signal (si) and the second signal (so) by acting on the first signal transmission path (34) to the first signal input (2) and / or on the first signal generator generating the first signal (si).

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