Method for detecting the earliest received time point of a signal change and method for measuring transmission time or for defending against relay attacks

Abstract

The invention relates to the earliest received time point for detecting a signal change. In particular, the method according to the invention allows earlier detection of signal changes, which significantly reduces the time span available for undetected relay attacks and thus makes it possible to prevent such relay attacks or at least make them significantly more difficult, without having to change the data transmission technology constituting the transmission system, such as UMTS, LTE or Bluetooth, for this purpose or for the required ultra-wideband signals. The problem is achieved in that the earliest time point for a statistically significant change of the signal is selected as the earliest received time point, wherein a threshold value for statistical significance is determined from the signal itself.

Description

Technical Field

[0001] The present invention relates to the earliest received time point for detecting a signal change. Background Art

[0002] A known solution is to sample the received pulses with a smaller and more precise step size. To this end, in order to better sample the received pulses, a new method is proposed, for example in A 1.9-mm-Precision 20-GHz Direct-Sampling Receiver Using Time-Extension Method for Indoor Localization by Han et al., IEEE Journal of Solid-State Circuits, June 2017, Vol. 52, No. 6, pp. 1509-1520, DOI 10.1109 / JSSC.2017.2679068, which is direct sampling with time extension, in which high time resolution sampling is performed during short pulses and the sampled pulses are analyzed between pulses. In Song et al., A Secure TOF-Based Transceiver with Low Latency and sub-cm Ranging for Mobile Authentication Applications, EEE Symposium on Radio Frequency Integrated Circuits, June 2018, pp. 160-163, DOI 10.1109 / RFIC.2018.8429022, it is proposed to improve the authentication effect by using the round-trip time of the pulse signal to perform binary phase shift keying and pulse phase modulation on the received and retransmitted pulses.

[0003] In addition, known digital transmission systems such as Bluetooth, UMTS or LTE encode and transmit information in symbols and / or chips. Here, according to the data to be transmitted, (rarely) the same symbol or chip or (usually) different symbols or chips are continuously transmitted to obtain symbols and / or chips of more transmission streams. Symbols or chips are transmitted in symbol and / or chip periods respectively. The transmission of symbols or chips requires a duration usually predetermined, and then the next symbol or next chip can be transmitted in a subsequent symbol or chip period. However, the received signal is usually used alone to decode the information encoded therein. For this purpose, the method used is to synchronize the time portion and / or incompleteness of the objects involved in the transmission, especially the transmitter and / or receiver, and especially to make the receiver recognize at least with a predetermined accuracy which time portion of the signal it is to decode the first information, and which time portion it is to decode the subsequent information, etc. The transmitter usually uses a bidirectional link, in which both parties act as both transmitters and receivers, and transmit control signals at least in two directions. Although it is important for sound transmission: the receiver recognizes which time portion of the received signal it can decode the first information. However, particularly precise time synchronization relative to the symbol or chip period in a transmission system is not usually sought and is not particularly advantageous in practice. However, in otherwise identical system designs, shorter symbol or chip periods allow for higher data transmission rates.

[0004] For this purpose, a clock is used in the Bluetooth standard and the other communication partners work with a deviation from this clock. For this purpose, each communication partner uses its own clock, which measures the time (non-synchronized) with an accuracy of approximately 3 μs. For synchronization, for example, the CSP mechanism is used for synchronization. The synchronization accuracy provided by the CSP is approximately 1 ms. In general, known transmission systems implement time synchronization or signal transmission time propagation timing with an accuracy corresponding to the symbol rate up to one quarter of the maximum symbol rate.

[0005] In practice, in particular in wireless transmission, multipath effects occur, which can cause different parts of the radiated signal to arrive at the receiver at different times, in particular because they have traveled different routes between the transmitter and the receiver. These parts usually coincide again at the receiver. In this case, the signal component part that arrives first is not necessarily the most powerful component part. Therefore, the transmission system usually uses only the component parts in the middle of the symbol or chip period for decoding.

[0006] In existing systems, the signal propagation time between a transmitter and a receiver is measured, for example in order to partially synchronize the clocks of the transmitter and receiver involved.

[0007] From pure distance measuring systems that evaluate the transmission time of a signal pulse, for example from EP 3 098 626 A1 it is known that when the signal reaches the transmitter after being reflected by a comparator, a signal generator is started when a preset signal amplitude is exceeded, which also generates repeated edges and the time of arrival of the pulse is inferred by sampling the edges. However, based on the exceeding of the preset signal amplitude, it is also known to match the triggering of the threshold circuit to the total signal strength by means of normalization. Summary of the invention

[0008] The object of the invention is to enable a more precise determination of the time of the earliest reception of a signal change. This can be used, for example, to improve transmission time measurements, in particular for distance measurement and / or synchronization, but also for detecting and protecting against relay attacks, as well as for shortening symbol or chip periods or for increasing the stability of a transmission system. In particular, a predetermined and / or constant signal amplitude is not exceeded.

[0009] Another object of the present invention is to provide a method for detecting and / or defending against relay attacks, a method for access control, authentication, distance measurement, synchronization and / or detecting and / or defending against relay attacks and access control systems using the earliest reception time of a signal change and / or the time point of a signal edge, and a method for protecting an access system.

[0010] In particular, the method according to the present invention enables early detection of signal changes, such as signal changes of a signal received in a receiver, which significantly reduces the time available for an undetected relay attack, thereby preventing a relay attack or at least making it significantly difficult, without having to change existing data transmission systems such as UMTS, LTE or Bluetooth or transmission technologies requiring ultra-wideband signals.

[0011] The accuracy of the method depends in particular on the transmission quality between the transmitter and the receiver. The method is particularly suitable for the current transmission conditions and can therefore be used in particular under poor transmission conditions and provides a particularly high accuracy under good transmission conditions.

[0012] The object is also achieved by a method for determining the time of the earliest received signal change and / or signal edge, which method is particularly used for transmission time measurement, in particular for distance measurement or synchronization in transmission systems, in particular synchronization symbolic and / or digital transmission systems.

[0013] Any transmission system or any transmission standard that meets the requirements described below can be used, in particular existing systems or standards can also be used. In particular, existing hardware can usually also be used, and usually only a corresponding management system needs to be set up in software. This is usually possible without compromising compatibility with standards or other devices.

[0014] With the aid of a transmission system, at least one first plurality of symbols and / or chips are transmitted from a first object to a second object in at least one first encoded analog signal at a first symbol rate or chip rate, and / or from a first object to a second object in at least one second analog signal generated based on the first analog signal.

[0015] The first plurality of symbols and / or chips is arbitrary. It is important that the first signal has at least one edge, which is common, for example, for the encoding of 0s and 1s. For example, the first signal can be a low-frequency signal, for example in the kilohertz or megahertz range, which is mixed, for example, with a carrier signal, thereby forming, for example, a second analog signal which usually has a higher frequency, for example in the gigahertz range. This second signal can then be transmitted, for example, by radio and received by a receiver.

[0016] Ordinal numbers used to more accurately represent plural numbers should not represent order, especially time order, but are only used to distinguish different plural numbers. For example, other arbitrary representations, such as plural number A (replacing the first plural number), plural number B (replacing the second plural number), plural number C (replacing the third plural number), etc. are also feasible.

[0017] In particular, the third plurality of numbers is smaller than or equal to the first plurality of numbers and / or the third plurality of transmitted symbols and / or chips is a subset of or equal to the first plurality of symbols and / or chips.

[0018] In particular, the fifth plurality of numbers is smaller than or equal to the first plurality of numbers and / or the fifth plurality of transmitted symbols and / or chips is a subset of or equal to the first plurality of symbols and / or chips.

[0019] In particular, the fifth plurality of numbers is equal to the third plurality of numbers and / or the fifth plurality of transmitted symbols and / or chips is equal to the third plurality of transmitted symbols and / or chips.

[0020] In known transmission systems, there is usually an adaptation of the (relative) time measurement in the transmitter and receiver in order to unambiguously identify when the transmission of an information unit, such as a symbol and / or a chip, begins and / or ends, and / or when a symbol and / or chip period begins and / or ends. Therefore, the system is usually symbol-synchronized. From this synchronization, distance measurements can also be derived, but these do not reach these feasibility in the analysis according to the invention. Here, the period, in particular the symbol and / or chip period, represents the inverse of the rate, in particular, the symbol period represents the inverse of the symbol rate and / or the chip period represents the inverse of the chip rate.

[0021] Symbols and / or chips can represent, transmit and / or encode any information and / or useful data. Information, symbols or chips that are independent of the method and / or the detection of the earliest time point, such as useful data, and / or information about the signal or its edges, for example, can be transmitted to improve the method.

[0022] Thus, the method can be applied in conventional transmission systems and already transmitted data, symbols, chips and signals can be used for performing the analysis.The transmission of data specifically for the analysis is not absolutely necessary but can be advantageous.

[0023] According to the invention, a second plurality of samples of a third plurality of transmitted symbols and / or chips of at least one first or second analog signal at a second object is used to detect the earliest reception of a signal change and / or a signal edge of a symbol or chip relative to a previous symbol or chip change.

[0024] The second plurality may be identical in number to the first plurality, the same applies equally to the first and third plurality as well as to the second and third plurality. In any case, the second plurality of samples does not imply two groups of samples, since the ordinal number used before the word "plurality" is only intended to separate the different plurality numbers precisely. In particular, the value of each plurality is at least three, in particular the value is at least 10. The third plurality is typically smaller than the first plurality, since the symbols and / or chips transmitted by the third plurality of at least one first or second analog signal represent in particular a subset of the symbols and / or chips of the first plurality.

[0025] According to the present invention, the earliest received time point is selected as the time point at which there is a sample of the second plurality of samples, in particular in the signal and / or code chip period, or the earliest aggregation group, in particular in the signal and / or code chip period, consisting of the second plurality of samples, which time point shows a statistically significant change and / or the sample is higher or lower than a value determined from a fourth plurality of samples of the first and / or second analog signal, or is out of the range of values ​​determined from the fourth plurality of samples of the first and / or second analog signal.

[0026] An aggregate value is to be understood in particular as a value which is represented by mathematical means, for example by forming an arithmetic, geometric or other mean or median, i.e. a value formed from a plurality, a plurality or a group of values, in particular sample values.

[0027] A group of aggregate values, in particular a sample, may be understood to mean in particular a number, a plurality and / or a certain number of values, in particular sample values, which follow one another, in particular directly, in particular in a chronological order, and are combined into a group. From such an aggregate group, an aggregate value may be formed from a number, a plurality and / or a certain number of values, in particular sample values, by mathematical means, for example by forming an arithmetic, geometric or other mean value or median.

[0028] The earliest aggregation group is in particular a group having samples, in particular samples considered in a symbol and / or chip period, having samples selected earlier than samples of other considered aggregation groups. In particular, the aggregation groups are selected such that the time points of selection of their samples do not overlap and / or the earliest aggregation group, in particular the aggregation group considered in a symbol and / or chip period, in particular the aggregation group whose samples are selected earlier than samples of other considered aggregation groups.

[0029] In particular, the earliest received time point is selected as the time point at which there is a second plurality of samples, in particular in the signal and / or code chip period, and / or the earliest aggregation group, in particular in the signal and / or code chip period, consisting of the second plurality of samples, which time point shows a statistically significant change compared to the remaining samples of the second plurality of samples and / or samples of the first or second analog signal, and / or is higher or lower than a value determined from a fourth plurality of samples of the first and / or second analog signal, or deviates from a range of values ​​determined from the fourth plurality of samples of the first and / or second analog signal.

[0030] It is therefore checked when or in which sample or in which aggregation group a first change of the received first or second analog signal is detected, which first change satisfies at least one specific requirement, in particular related to the signal itself. The change is determined in particular by comparing the sample with an aggregate value, in particular, for example, an arithmetic mean or a median, from a fourth plurality of samples. The earliest possible time point is an absolute time point, which is measured, for example, relative to the clock of the transmission system. Here, usually, the time point is a time point within a symbol or chip period and is therefore a time point that occurs in multiple or all symbols or chip periods. Therefore, usually the time point is a repeated time point, in particular measured relative to a clock time or clock period, for example, measured relative to a clock or clock generator of the transmission system, in particular to the modulation of the symbol or chip period. Therefore, the absolute time point can also be selected as the time point of the earliest sample of the second plurality of samples, but it is advantageously the time point of the earliest sample of the second plurality of samples in the symbol and / or chip period. Thus, the accuracy can be improved by aggregating multiple samples of symbols and / or chips transmitted at different absolute times. According to the invention, a second plurality of samples of a third plurality of transmitted symbols and / or chips is selected such that the samples are selected at symbols and / or chips transmitted at different times, in particular in a symbol and / or chip period, and are at least five, in particular ten different, in particular in each case deviating by at least two percent of the symbol and / or chip period and / or by at least ten percent, in particular at least twenty percent. In particular, there are at least ten different first time points in a symbol and / or chip period, in particular each time point deviating by at least two percent of the symbol and / or chip period and / or at least ten percent, in particular at least twenty percent, the distance between the first time points in the symbol and / or chip period being in particular smaller than the minimum possible sampling interval of the second object of the transmission system.

[0031] The selected time points of the samples are therefore specifically set such that they are selected at different symbols or chips, ie, for example, in different symbol and / or chip periods. In addition, the time points together span, in particular, at least ten percent of a symbol and / or chip period.

[0032] In particular, the second plurality of samples is processed such that the second plurality of samples are grouped together when viewed modulo time of the symbol or chip period and / or are grouped together when viewed in time relative to a position within the symbol or chip period. Thus, measurements for a plurality of symbols and / or chips may be viewed together, thereby increasing accuracy under the assumption of constant transmission conditions. In particular, such samples are respectively viewed together and / or grouped together, and in particular their sequence, between which edges the combined and / or grouped samples are obtained, are in particular identical, at signal edges or signal changes that at least at the transmitter and / or theoretically behave in the same way, in particular at edges between two different symbols and / or chips.

[0033] In particular, the selected samples are divided into groups, each group being a sequence of two different consecutive symbols and / or chips. In particular, at least 10, in particular at least 100 samples are obtained for at least one group / in each group. In particular, at least 10 samples are obtained and / or divided into at least 10 times in a symbol or chip period.

[0034] The object is also achieved by a transmission system for carrying out the method according to the invention.

[0035] The object is also achieved by a method for protecting an access system, the access system comprising an authorization device and an access control device, wherein between the authorization device and the access control device, at least one first plurality of symbols and / or code chips are transmitted in an encoded manner at a first symbol rate or code chip rate in at least one first analog signal from the first of the two devices to the second of the two devices, and / or in at least one second analog signal generated based on the first analog signal from the first of the two devices to the second of the two devices via the transmission system, the earliest receiving signal change and / or signal edge The time of the edge is determined by the method or system according to the invention, and access, activation, deactivation and / or opening is denied by the access control device if a predetermined data reception time point deviates in time from an earliest reception time point and / or in the case of a deviation of the earliest reception time from a predetermined time slot or a time point calculated using another method, and / or the signal transmission time and / or the signal round trip time and / or the distance are determined based on the earliest reception time, and access, entry, activation, deactivation and / or opening is specifically denied by the access control device if a certain signal transmission time and / or the signal round trip time and / or the predetermined distance and / or a predetermined deviation of the signal transmission time are determined in another way or by another method, and / or the signal round trip time and / or the distance are exceeded.

[0036] The data reception includes in particular the reception of signal components used by the transmission system, in particular without the use of the method according to the invention, in order to identify, derive and / or decode information, data packets or bits therefrom, signal components, in particular without components which the transmission system (in particular without the use of the method according to the invention) does not use data packets or bits to identify, derive and / or decode. For example, this can be a constant signal state, for example a constant voltage, as is usually used to encode a 0 or a 1, but also an edge from which a bit is derived. The time of data reception is understood to mean in particular the start of the reception of signal components used by the transmission system, in particular even without the use of the method according to the invention, in order to identify, derive and / or decode information, data packets or bits therefrom, wherein, in particular, the signal components do not have components which the transmission system (in particular even without the use of the method according to the invention) does not use data packets or bits to identify, derive and / or decode.

[0037] The method, system and use according to the invention also achieve in particular a signal or signal change which is at most 10 dB, in particular at most 20 dB or even at most 30 dB lower than a signal component used by the transmission system for identifying, deriving and / or decoding information, data packets or bits without using the method according to the invention.

[0038] This allows signal components to have only relatively small signal components, components having, for example, signal components having at most or about 10 dB, in particular at most or about 20 dB, in particular at most or about 30 dB, signal components having amplitudes and / or variations that are greater than the maximum amplitude, and / or to detect variations in the received and / or transmitted signal, and / or in particular, when their distance from the maximum or greater amplitude is at least 1 / 8, in particular at least 1 / 20, in particular at least 1 / 80, in particular at least 1 / 250 of the symbol rate, and / or variations in the received signal, in particular if the second and / or fourth plurality of variations is greater than or equal to 400 and / or the second plurality of variations is at least 400, in particular consecutive edges and / or signal variations are used. The method, system and use are designed accordingly advantageously. This can be implemented in particular in existing transmission systems and existing hardware.

[0039] Likewise, in the method, system and use according to the invention, the accuracy of the time measurement, signal transmission time measurement, signal round trip measurement and / or time synchronization, in particular if the second and / or fourth plurality of changes is greater than or equal to 400 and / or the second plurality of changes is at least 400, in particular the immediately following consecutive edges and / or signal changes have been increased to 1 / 8, in particular 1 / 20, in particular 1 / 80 of the symbol rate of the transmission system. Likewise, in the method, system and use according to the invention, the accuracy of the time measurement, signal transmission time measurement, signal round trip time measurement and / or time synchronization can be achieved, in particular if the second and / or fourth plurality of changes is greater than or equal to 4000 and / or the second plurality of changes is at least 4000, in particular the immediately following edge and / or signal changes are adopted to increase the symbol rate of the transmission system to 1 / 25, in particular 1 / 60, in particular 1 / 250. The method, system and use are designed accordingly advantageously. This can be implemented in particular in existing transmission systems and existing hardware. Therefore, the subject matter of the invention is to improve a method for performing a method according to the invention or for creating a transmission system according to the invention.

[0040] The object is also achieved by an access control system having an authorization device and an access control device, wherein the access control system has a transmission system, in which at least a first plurality of symbols and / or chips are arranged electrically, magnetically or electromagnetically between the authorization device and the access control device and are transmitted at a first symbol or chip rate in at least one first analog signal from a first one of the authorization device and the access control device to a second one of the authorization device and the access control device and / or in at least one second analog signal generated based on the first analog signal from the first authorization device and the access control device to a first one of the two devices, the access control system being configured to determine the time at which a signal change and / or a signal edge is first received by one of the above-mentioned methods, When the data reception time point has a predetermined time deviation from the earliest reception time point, and / or in the case of a deviation between the earliest reception and a predetermined time or a time calculated using other methods, the time of access, activation, deactivation and / or opening is denied, in particular by the access control device, and / or the signal transmission time and / or the signal round trip time and / or the distance are determined based on the earliest reception time and a predetermined signal transmission time and / or signal round trip time, and / or in the case of a predetermined deviation amount, access is denied, in particular access, entry, activation, deactivation and / or opening of the access control device, and / or the denial is implemented by the access control device in another way or by other methods or other devices with specific signal transmission time and / or signal round trip time and / or distance.

[0041] The object is also achieved by using the time point of the earliest received signal change and / or signal edge for access control, authentication, distance measurement, synchronization and / or for detecting and / or defending against relay attacks, wherein at least one first plurality of symbols and / or code chips are transmitted in an encoded manner from a first object to a second object in at least one first analog signal at a first symbol rate or code chip rate with the aid of a transmission system, and / or are transmitted from the first object to the second object in at least one second analog signal generated based on the first analog signal, and a second plurality of samples of the transmitted symbols and / or code chips of at least one first or second analog signal at the second object are used to: detect the earliest reception of a signal change and / or signal edge of a symbol or code chip relative to a previous symbol or code chip change, wherein the following time point is selected as the time point of earliest reception, at which time point the received first A first change of one or a second analog signal and / or of an aggregate group of received first or second analog signals, said first change being statistically significant and / or at said point in time exceeding or falling below a value determined from a fourth plurality of samples of the first and / or second analog signal or leaving a range of values ​​determined from a fourth plurality of samples of the first and / or second analog signal, wherein a second plurality of samples of a third plurality of transmitted symbols and / or chips is selected such that the samples are taken from symbols and / or chips transmitted at different times, at least five, in particular at least ten different times, in particular with a deviation in each case of at least two percent of the symbol and / or chip period and / or at least ten, in particular at least 20%, of the frame shift symbol and / or chip period, the distance between the time points in the symbol and / or chip period being in particular smaller than a minimum possible sampling interval of a second object of the transmission system.

[0042] The above statements regarding the method of determining the earliest receipt time apply to the same terms and methods for protecting access to the system, its use and / or the system.

[0043] In particular, with regard to the method, use and / or system, access, activation, deactivation and / or opening is granted by the access control device and / or the access control device if there are no deviations and / or excesses. In particular, access, entry, activation, deactivation and / or opening is only granted if there are no or only a predetermined number of deviations and / or excesses in a large number of repetitions, or if there are no or at most a predetermined number of deviations and / or excesses.

[0044] In particular, access, entry, activation, deactivation and / or opening is only permitted if at least one further authentication requirement is met, such as the correct password being entered or the certificate being valid and / or marked as permitted in the access system. It is particularly advantageous if the at least one authentication request contains a number of authentication requests that are dependent on the time of receipt, in particular after a registration and / or at least one authentication request that is independent of the time of receipt. Regardless of the time of receipt, the validity of the certificate is also time-dependent, but not directly dependent on the time of receipt.

[0045] In particular, access is not only access to an area in the sense of possible movement of objects and / or persons in the area, such as the interior of a room or a vehicle, but also in particular access to a function, in particular the meaning of activating a function can also be understood, such as access to a function to start or start a vehicle or access to the "brew coffee" function of a coffee machine. Access control systems are therefore not only such access control systems that control, limit and / or protect access only in the access range, in terms of possible movement of objects and / or persons into the area, but also in particular those that control access to functions, in particular in the sense of activating functions, limiting and / or protecting. Access control systems are in particular authorization systems, such as for logging into a computer system, for example by means of a password and / or a certificate, or also conventional access control systems, such as locks, barriers, doors and / or locking and / or activating functions, such as service stations, such as coffee machines. In particular, it can be a door and / or ignition lock and / or starter of a vehicle (for example a motor vehicle, an aircraft, a ship or an autonomous taxi - and all other conceivable vehicles). It can also be access and / or activation of any service station (ATM, telephone, coffee machine - the list can be extended as required). For example, a mobile phone, a key, a certificate and / or an input system for entering a password may be considered as an authorization device.

[0046] In particular, the transmission system according to the method, application and / or system is a wireless transmission system, such as a radio key or a near-field key, in particular for a motor vehicle, and a wireless transmission system for communication, for example between motor vehicles, or two Bluetooth modules.

[0047] In particular, with regard to the method, application and / or system, a signal change is recognized and / or accepted and / or access, entry, activation, deactivation and / or opening is granted and / or a signal change according to the invention is present only if:

[0048] - when the signal change is an expected and / or predetermined and / or agreed signal change, and / or

[0049] when the signal change is based in particular on an information coding of symbols and / or chips and / or signals exchanged between a first and a second object, in particular between a transmitter and a receiver,

[0050] - when the signal change encodes information which is predetermined and / or computable using symbols and / or chips exchanged between the first and second objects, in particular between a transmitter and a receiver, and / or

[0051] - when the signal change has a form and / or type, in particular based on symbols and / or chips and / or signals exchanged between a first and a second object, in particular between a transmitter and a receiver, and / or

[0052] when the signal change has a form and / or type which is predetermined and / or can be calculated using symbols and / or chips exchanged between the first and the second object, in particular between a transmitter and a receiver,

[0053] Here, information, type and / or form need not be predetermined and / or can be calculated as specific precisely defined information, type and / or form, and / or can be predetermined and / or calculated by means of specific precisely defined information, type and / or form, but predetermined tolerances and / or predetermined deviations from predetermined and / or calculated information, type and / or form are also allowed. Further protection can be achieved thereby, because the type of signal change, the predetermined and / or calculated form and / or the predetermined and / or calculated information must also be known to the attacker. Information can also be predetermined and / or calculated by previous communication and / or transmission, and / or information can also be predetermined and / or calculated by previous communication and / or transmission. A particularly simple type of predetermined and / or calculated shape is, for example, the type of edge, which is characterized as a falling edge or a rising edge. Even if this simple type only provides relatively low security in a single application, security is significantly improved when the method is applied multiple times or several times. It is preferred that the shape is predetermined and / or calculated as a rising edge or a falling edge and / or that the coded predetermined and / or calculated information is predetermined and / or calculated as 0 or 1. In particular, access, entry, activation, deactivation and / or opening is only permitted if a number of authentication requirements related to the reception time, in particular according to the present application, in particular according to claim 1 thereof, are met, in particular in addition to at least one other authentication requirement.

[0054] In particular, a plurality of time points for the earliest reception of a plurality of signal changes and / or a plurality of signal edges are determined by means of one of the aforementioned methods, and if a predetermined number of times exceeds a predetermined and / or calculated deviation of the respective reception from the respective time of the earliest reception and / or if a deviation of the respective earliest reception from the respective predetermined and / or calculated is exceeded or using other methods, in the event of a predetermined number of exceeded deviations of the respective reception from the respective time of the earliest reception and / or in the event of a deviation of the respective earliest reception from the respective predetermined and / or earliest reception time calculated by means of other methods, the calculated time window denies access, entry, activation and / or opening by means of the access control device.

[0055] By means of the method, application and / or system, it is possible, for example, to ensure with high accuracy that access is only permitted if an authorized device is present in a predefined distance range or volume range and / or spatial range and / or if it is ensured that no relay attacks are present. It is particularly advantageous that this is possible in many modern systems without requiring hardware changes.

[0056] It is particularly advantageous to use samples of a fifth plurality of transmitted symbols and / or code chips of at least one first or second analog signal at the second object as a fourth plurality of samples, in particular to assign a significance level and / or a specific value or value range, in particular depending on the standard deviation or the width of the fluctuations or scattering of the fourth plurality of samples.

[0057] In particular, a statistically significant variation is assumed if the variation reaches or exceeds x times the standard deviation of the fourth plurality of samples, or wherein the determined value is the mean or median of the fourth plurality of samples plus or minus x times this width. The fluctuation within the fourth plurality of samples or the scatter is or wherein the particular value range extends to twice the width of the fluctuation within the fourth plurality of samples or the scatter, in particular around an aggregate value, in particular the scatter extends, for example, from the arithmetic mean or median of the fourth plurality of samples, or wherein the determined value is x times the width of the fluctuation or scatter plus, for example, one from the arithmetic mean or median of the fourth plurality of samples.

[0058] x is advantageously in the range between 0.4 and 5, in particular between 0.5 and 3, in particular between 1 and 3.

[0059] In particular, the harmonic, cubic, geometric, quadratic or preferably arithmetic mean, median or mode is used as mean.

[0060] In particular, the standard deviation of a set of values ​​is used as an empirical standard deviation of the deviations of the set of values ​​from its mean. In particular, the standard deviation mathematically represents the average deviation of the values ​​from the mean.

[0061] Advantageously, samples of a fifth plurality of transmitted symbols and / or code chips of at least one first or second analog signal at the second object are used as a fourth plurality of samples, and the fourth plurality of samples of the fifth plurality of transmitted symbols and / or code chips are selected such that their samples are selected at symbols and / or code chips transmitted at different times and are at at least five, in particular at least ten different second time points in the symbol and / or code chip period, the second time points in particular deviating from at least two percent of the symbol and / or code chip period and / or being frame-shifted by at least ten percent, in particular at least twenty percent, of the symbol and / or code chip period, respectively.

[0062] This makes it possible to achieve, from the signal itself, an in particular dynamic adaptation of the threshold value for detecting the earliest point in time and to respectively increase the accuracy, in particular in the event of changing transmission conditions.

[0063] Advantageously, the spacing between the second time points in the symbol and / or chip period is in particular less than the minimum feasible sampling interval of the second object of the transmission system, in particular at most half of the sampling interval. This means that the functions of the hardware used can be optimally utilized. Advantageously, at least under theoretically considered optimal transmission conditions at the transmitter and / or at the receiver, the fourth plurality of samples of the fifth plurality of transmitted symbols and / or chips are in a section of the symbol and / or chip period, in which or on which at least one first and / or second analog signal is constant and / or has a constant level. Particularly high precision can thereby be achieved. The knowledge of when such conditions are given can be derived at least approximately relative to the symbol and / or signal period, in particular with knowledge of the specifications of the transmission system and / or from the variation of the signal itself.

[0064] It should be noted that the time points in the symbol and / or chip period at the receiver and / or the segments in the symbol and / or chip period at the receiver are on an absolute clock at different times from the same time points in the symbol and / or chip period at the transmitter and / or the segments in the symbol and / or chip period at the transmitter, i.e., the signal transmission time from the transmitter to the receiver is staggered.

[0065] Advantageously, at least one property of the first or second signal, such as level and / or amplitude and / or phase, is used to determine a change, a significance level, a width of fluctuations or scattering and / or a predetermined value and / or a value range of the first or second signal and / or as a change of the received first or second analog signal, a change of at least one characteristic of the received first or second analog signal. The earliest received point in time may be the point in time of the earliest sample value or group of aggregates which exceeds or falls below a determined value or leaves a value range determined from a fourth plurality of samples of the first and / or second analog signal with respect to at least one or all of the at least one property.

[0066] For example, only the phase of the samples and / or only their amplitude can be used. It is also possible to take both into account and use the time of the earliest sample as the earliest received time, which satisfies one or both criteria, such as exceeding or falling below a value range in terms of amplitude and / or leaving a value range in terms of amplitude.

[0067] The level and / or amplitude and / or phase are common and proven characteristics of the signal, in the variation of which the symbols and / or chips are encoded, for example amplitude shift keying (ASK) or phase shift keying (PSK), i.e. for example multiphase shift keying (MPSK), Gaussian frequency shift keying (GFSK) or quadrature amplitude modulation (QAM). The method according to the invention can be implemented particularly simply and reliably by means of or according to the first and / or second signal modulated in these ways and / or in a transmission system using such a modulation or in a device using such a modulation.

[0068] Advantageously, the second analog signal is generated from the first signal by mixing and / or at a high frequency, and / or the second signal has a higher frequency than the first signal, and / or the first signal is reconstructed as far as possible at the second object from the second signal at the second object before sampling, in particular by mixing.

[0069] Advantageously, the second plurality is equal to the fourth plurality and / or the third plurality of transmitted symbols and / or chips is equal to the fifth plurality of transmitted symbols and / or chips. This does not mean that these are identical samples, but only the number of samples which are advantageously chosen to be identical.

[0070] Advantageously, the first time point and the second time point are selected such that the first time point is in a first time span of a symbol and / or chip period and the second time point is in a second time span, and the first time span and the second time span do not overlap in the symbol and / or chip period.

[0071] Advantageously, the transmission system is bidirectional. Here, user data can be transmitted in both directions, or user data can be transmitted only in one direction and at least control data, such as a channel quality indicator (CQI) or an acknowledgement (ACK) signal, can be transmitted in the other direction. The method according to the invention or the use according to the invention is advantageously applied to two transmission directions. Then, for one transmission direction, the first object is a transmitter, the second object is a receiver, and the roles and / or numbers of the objects are interchanged with respect to the opposite direction. In particular, in such an embodiment, a signal round trip time is determined based on at least one earliest time point at the first object and based on at least one earliest time point at the second object, in particular a signal round trip time from the first object to the second object and back or in the opposite direction. In particular, the signal round trip time is used to determine the distance between the first and second objects.

[0072] Advantageously, the symbol and / or the chip transmits at least partially encrypted information, in particular at least partially encrypted information about the course of the first and / or second analog signal, and / or inferred information about the course of the first and / or second analog signal, and wherein such inferences can be derived and used at the second object, for example for selecting one or more of the plurality and / or for defining one or more time periods, sections and / or points in time. The symbol and / or the chip particularly advantageously transmits at least partially encrypted information, in particular at least partially encrypted authorization information, such as a password or a certificate. With this configuration, the security against attacks can be further increased.

[0073] Advantageously, with respect to the method, use and / or system,

[0074] - when the signal change is a signal change of a previously encrypted and / or encrypted communication, and / or

[0075] - when the signal change encodes information which is encrypted and exchanged between the first and the second object, in particular the transmitter and the receiver,

[0076] - when the signal variation encodes information calculated in an encrypted manner using the first and second objects, in particular the transmitter and the receiver, and / or

[0077] - when the signal change encodes the form and / or type of data which are encrypted and exchanged between the first and second objects, in particular the transmitter and the receiver, and / or

[0078] when the signal change is of a form and / or type which can be calculated in an encrypted manner using data exchanged between the first and the second object, in particular the transmitter and the receiver,

[0079] The signal change itself is recognized and / or accepted and / or access, entry, activation, deactivation and / or opening is permitted and / or a signal change according to the invention is present.

[0080] Advantageously, the second and / or fourth plurality of samples are equidistant within the symbol and / or chip period and / or the second and / or fourth plurality of samples are equidistant over time, wherein in particular their spacing in time is chosen such that their position in the symbol and / or chip period is repeated after five symbols and / or chips at the earliest, in particular after ten symbols and / or chips at the earliest.

[0081] It is particularly advantageous to divide the symbol and / or code chip period into at least three non-overlapping time ranges and / or to define at least two, in particular three, non-overlapping time ranges in the symbol and / or code chip period, wherein a first time point is within a first of the three ranges and a second time point is within a second of the three ranges, wherein the first range and the second range are in particular adjacent to each other and / or the third range is not between the first and second ranges.

[0082] This makes it possible to further increase the accuracy of the method in the event of inaccurate synchronization and / or varying ambient conditions.

[0083] Thus, for example, it can be ensured that: a fourth plurality of samples of a fifth plurality of transmitted symbols and / or code chips of at least one first or second analog signal at the second object are selected in the region of the symbol and / or code chip transmission period, wherein a signal that is as constant as possible can be calculated, in particular also taking into account to be expected inaccuracies, and / or in said region, in which there are no edges and / or transient processes and / or no transitions generated by Gaussian frequency shift keying (GFSK), and / or in said region, a constant first and / or second signal is emitted, for example at the first object.

[0084] Particularly advantageously, the synchronization accuracy between a first object and a second object in a transmission system, in particular without using the method according to the invention, is selected such that a deviation between the first and second objects, in particular a deviation of a clock, a clock generator and / or a time measuring device, is a maximum of 50% of the symbol and / or chip period, in particular in the range of 10% to 50% of the symbol and / or chip period.

[0085] It is particularly advantageous if the samples are taken after signal processing, for example by mixing, rectification and / or smoothing.

[0086] Particularly advantageously, the detection of the earliest point in time at the second object can be used to: send a signal from the second object, in particular with a predetermined and / or communicated time correlation with the earliest point in time. In particular, the detection of the earliest point in time at the second object can be used to: perform the method according to the invention a second time, wherein the first and second objects are exchanged with each other and wherein in particular the earliest point in time and / or its temporal position relative to the time of a timer or clock of a transmission system is transmitted, in particular to the first object and / or to a first analog signal of the second embodiment and / or to the second object of the second embodiment, and / or wherein the analog signal of the second embodiment has a predetermined and / or communicated relationship with the earliest time of the first embodiment.

[0087] Advantageously, the earliest reception of a signal change can be determined at a plurality of antennas and the direction of incidence of the signal change can be determined therefrom, wherein the antennas are located at a distance from one another, in particular with a spacing of at least 0.5 m between two antennas in a fixed arrangement relative to one another. Advantageously, the direction of incidence can be used for authentication and / or for identifying an authentication request. Advantageously, an antenna is arranged at the motor vehicle, the switching on or activation and / or operation of which is ensured and / or limited by the method, system and / or use according to the invention.

[0088] Thus, for example, a plurality of antennas can be arranged in a motor vehicle and a specific direction of incidence can be determined by determining the orientation relative to the motor vehicle. For example, the vehicle can only be started if the direction of incidence is within a predetermined angular range relative to the forward direction of travel of the motor vehicle, in particular if the direction of incidence indicates a position of the transmitter behind the steering wheel in the forward direction of travel of the motor vehicle and / or assumes a position of the transmitter within the vehicle together with the distance.

[0089] Advantageously, the transmission system and / or the first and / or the second signal are designated transmission systems and / or first and / or second signals and received signals having a significantly higher bandwidth, in particular at least 1.5 times the bandwidth, are aggregated to the designated bandwidth of the received signals and the bandwidth of the signals and the signals detected in the sampling are used for authentication of the type and, if a predetermined bandwidth is exceeded, access, entry, activation, deactivation and / or switching on is blocked.

[0090] The system is advantageously configured to perform one or more advantageous methods and / or uses. In particular, the system is a hardware and software system having at least one transmitter and receiver, and in particular at each object having at least one analog-to-digital converter for generating samples and / or a digital-to-analog converter for generating the first and / or second signal, and in particular at each object, and / or in particular at each of the objects having at least one CPU. In particular, the method and / or use uses such a hardware and software system. In particular, the software is configured as hardware for performing the method and / or use according to the invention.

[0091] It is particularly advantageous to transmit at least one first plurality of symbols and / or code chips at a first symbol or code chip rate from a first object or multiple times in at least one first encoded analog signal to a second object and / or in particular from a first object to a second object in at least one second analog signal generated based on the first analog signal.

[0092] It is particularly advantageous if at least a first plurality of symbols and / or chips are transmitted or the transmission is performed multiple times at a first symbol or chip rate in a plurality of first or second analog signals and in each case at least one first plurality of symbols and / or chips is encoded in particular from a first object to a second object at the first symbol or / chip rate.

[0093] Particularly advantageously, a plurality of receiving devices are arranged in a fixed position connected to the second object but spaced apart therefrom, in particular spaced apart by at least 10 cm, and / or the time point of the earliest reception of a signal change and / or a signal edge is determined for each of the plurality of receiving devices of the second object. In particular, the second object and the plurality of receiving devices are part of a motor vehicle, and / or the first object is an access device, in particular a wireless key. In particular, the direction and / or distance of the first object is determined based on a third plurality of transmitted symbols and / or chips of at least one first or second signal used at the second object, in particular by triangulation, in particular based on the difference in the time points of the earliest reception at the plurality of receiving devices of the second object. In particular, the determined distance is checked for consistency with the time point of the earliest reception. In particular, the angle and / or the angle difference between the first and second objects and / or one of the plurality of receiving devices and / or between the first object and one of the plurality of first receiving devices is determined based on a third plurality of transmitted symbols and / or chips of at least one first or second signal used at the second object, in particular by phase comparison of the third plurality of transmitted symbols and / or chips of at least one first or second signal.

[0094] It is particularly advantageous that a plurality of transmission devices of the first object are arranged in a manner that is fixedly connected to the first object but spaced apart therefrom, in particular spaced apart by at least 10 cm, and the transmitting device is used for transmission, and / or a plurality of first objects are arranged in a manner that is fixedly connected to the first object but spaced apart therefrom, in particular spaced apart by 10 cm, and the method according to the invention is performed for each of the plurality of first objects, and in particular the earliest point in time of reception of a signal change and / or a signal edge is determined for each first object and / or each transmitting device from a third plurality of transmitted symbols and / or code chips of at least one first or second signal used at the second object.

[0095] Particularly advantageously, based on the phase change of the third plurality of transmitted symbols and / or chips of the at least one first or second signal used at the second object and / or based on the difference in the earliest received time points, the distance and / or the change in orientation between the first and second objects is determined and / or therefrom it is determined how long at least two signal paths of the third plurality of transmitted symbols and / or chips of the at least one first or second signal differ, in particular assuming a static arrangement and environment of the first and second objects during the transmission of the first or second signal. In particular, the shortest signal path and / or the signal component which has been received via the shortest signal path is determined.

[0096] In particular, the direction and / or distance of the first object is determined based on a third plurality of transmitted symbols and / or chips of at least one first or second signal of a transmitting device used at a plurality of first objects and / or second objects, in particular by triangulation, in particular based on the difference in the earliest reception time of the signal from the first object and / or the transmitting device of the first object. In particular, the determined distance is checked for consistency with the earliest reception time.

[0097] It is particularly advantageous to determine the angle of incidence difference between the first and second objects based on a phase change between a third plurality of transmitted symbols and / or code chips of at least one first or second signal used at the second object, and / or to determine therefrom: the angle by which at least two signal paths of a third plurality of transmitted symbols and / or code chips of at least one first or second signal differ, in particular assuming a static setup and environment of the first and second objects and / or the receiving device and the second object during transmission of the first or second signal.

[0098] It is particularly advantageous to determine the difference in the angle of incidence between the first and second objects based on a phase change between the received second signal and a plurality of further received second signals, and / or to determine therefrom: the angle by which at least two signal paths of the second signal and these further second signals differ, in particular assuming a static setting and environment of the first and second objects and / or the receiving device and the first and / or second objects during the transmission of the second signal and these further second signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Further advantageous improvements and advantages are further explained by way of example and not limitation by means of the following simplified drawings. In the drawings:

[0100] Figure 1 A schematic diagram showing a sending module and a receiving module in the prior art is shown.

[0101] Figure 2 A diagram showing an aggregation of measurement values ​​from different symbol periods,

[0102] Figure 3 A diagram of the method according to the invention is shown. DETAILED DESCRIPTION

[0103] Figure 1 The schematic structure of the transmitting module and receiving module in the prior art is shown. Such a module is provided by, for example, the Texas Instruments CC25 chip. Such a transmitting and receiving module is suitable for: transmitting data by the I&Q method, for example, using the Bluetooth standard.

[0104] An antenna 1 is shown which is externally connected to the chip. The signal received by the antenna passes through an input amplifier 3 and is then split into two signals. The two signals are fed to two mixers 4 and are then fed to the corresponding analog-to-digital converters 6 via a bandpass filter 5, respectively. In addition, the signal generated in the frequency synthesizer 14 is fed to one of the mixers 4, while the signal of the frequency synthesizer 14 is fed to the other mixer 4 only after passing through a phase shifter 13. I and Q signals can therefore be obtained from the mixer 4. After the analog-to-digital converter 6, the I and Q signals are then fed to the demodulator 7 in digital form and are then transmitted to the data packet processor 9 and the input memory 10 via an error correction and decoding unit 8. From there, the signal reaches the interface driver 11, through which the data becomes available via the input 12, for example, for further processing by a CPU.

[0105] The data to be transmitted can be transmitted to the interface driver 11 via the input 12 and then written to the output memory 16 and transmitted to the error correction and decoding unit 8 via the packet processor 9. The signal generated in this way is then transmitted to the transmission amplifier 2 and the antenna 1 via the modulator 15 and the frequency synthesizer 14.

[0106] If such a module is applied to the method, application or system according to the invention, in addition to the received data usually provided via the input 12, further sampling values ​​or samples of the analog-to-digital converter 6 are also intercepted, which, although usually collected in the analog-to-digital converter 6, are usually only used in a subsequent stage to decode or recover the digital data stream from the first and / or second signal, but are not subsequently passed on or used, for example not from the code chips used, here for example via the input 12.

[0107] Although in principle it is also possible to provide samples via input 12, which can be achieved by changing the firmware, other data inputs and / or outputs are also conceivable. In principle, the hardware included, in particular the memory, together with the CPU and corresponding software is sufficient to implement the method according to the invention or to form the object of the system according to the invention.

[0108] Figure 2In the upper part, a signal of a digital data transmission system is shown, which signal switches alternately between two states, for example 0 and 1, and has edges located therebetween. In the lower part, the measured values ​​(samples) of the upper signal are plotted as bold points. At the measurement points located at the falling edges, dashed lines are drawn in the upper part to clarify the position in the upper signal. The positions of the samples or measurement points collected at consecutive falling edges in a symbol or period are indicated by the three arrows in the upper part. It can be seen that the time-shifted sampling of the signal, for example of three falling edges, at different times in the symbol or chip period enables the detection of repeated falling edges with a very high time resolution.

[0109] Figure 3 A diagram of a method according to the invention is shown. In the diagram of the amplitude axis 17 and the time axis 18 of the receiver, a signal 20 at the transmitter and an aggregate sample 19 of the signal received at the receiver are shown, which is time-shifted during the propagation time of the signal from the transmitter to the receiver. The points each represent ten aggregate samples 19 taken at different symbols transmitted at different times in a symbol period. Here, the size of the circle characterizes the inaccuracy of the aggregate sample in terms of time and in terms of amplitude.

[0110] The symbol period 22 is shown and divided into three ranges, namely a first range 21a, a second range 21b, and a third range 21c. The limits of the width of the fluctuations 23a, 23b of the average value of the samples in the second range 21b are also shown, and the upper limit 24a and the lower limit 24b of the value range are shown, which are derived from the fluctuation width by multiplying with the coefficient x, around the arithmetic mean of the aggregated samples in the second range 21b. It can also be seen that the first aggregated sample value 26 exceeds or falls below the upper limit 24a and the lower limit 24b of the value range. This defines the earliest point in time 27 at which the received signal changes.

[0111] Reference numerals list

[0112] 1 Antenna

[0113] 2 Transmitter Amplifier

[0114] 3 Input Amplifier

[0115] NF Low Frequency Signal

[0116] 4 Mixer

[0117] HF High Frequency Signal

[0118] 5 Bandpass filter

[0119] 6 Analog-to-digital converter

[0120] 7 Demodulator

[0121] 8 Error correction and decoding unit

[0122] 9 Packet Processor

[0123] 10 Input memory

[0124] 11 Interface Driver

[0125] 12 Input

[0126] 13 Phase Shifter

[0127] 14 Frequency Synthesizer

[0128] 15 Modulator

[0129] 16 Output memory

[0130] 17 Amplitude axis

[0131] 18 Timeline

[0132] 19 Aggregate Samples

[0133] 20 Signal at the transmitter, delayed by signal travel time

[0134] 21a First Range

[0135] 21b Second Range

[0136] 21c Third Range

[0137] 22 symbol period

[0138] 23a Upper limit of mean fluctuation

[0139] 23b Lower limit of mean fluctuation

[0140] 24a Upper limit of the value range

[0141] 24b Lower limit of the value range

[0142] 25 Width of mean fluctuations

[0143] 26 First aggregate sample value

[0144] 27 Earliest time point

Claims

1. A method for determining the earliest point in time of reception of a signal change and / or a signal edge, the method being used for transmission time measurement, for distance measurement and / or for synchronization in a synchronous symbolic and / or digital transmission system, wherein by means of the transmission system at least one first plurality of symbols and / or chips are transmitted in an encoded manner at a first symbol or chip rate in at least one first analog signal from a first object to a second object and / or in at least one second analog signal generated based on the first analog signal from a first object to a second object, wherein a second plurality of samples of a third plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object is used to determine the earliest reception of a signal change and / or a signal edge of a symbol or chip that deviates from a previous symbol or chip, wherein the earliest received time point is a time point at which there is an earliest sample of the second plurality of samples or an earliest aggregated group from the second plurality of samples, the earliest sample or the earliest aggregated group showing a statistically significant change, and / or at which there is an earliest sample of the second plurality of samples or an earliest aggregated group from the second plurality of samples, the earliest sample or the earliest aggregated group exceeding or falling below a value determined from a fourth plurality of samples of the first and / or second analog signal, or departing from a range of values ​​determined from a fourth plurality of samples of the first and / or second analog signal (24b, 24a), wherein the second plurality of samples of the third plurality of transmitted symbols and / or chips are selected so that the samples are selected at symbols and / or chips transmitted at different times and are located at at least five different first time points in the symbol and / or chip period, the first time points are respectively deviated from at least 2 percent of the symbol and / or chip period, and / or are respectively frame-shifted to at least 10 percent of the symbol and / or chip period, wherein the spacing between the first time points in the symbol and / or chip period is less than the minimum feasible sampling interval of the second object of the transmission system, Therein samples of a fifth plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object are used as the fourth plurality of samples.

2. The method according to claim 1, wherein samples of a fifth plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object are used as a fourth plurality of samples in order to determine a significance level and / or a specific value or value range from a standard deviation or a width of fluctuations or scattering of the fourth plurality of samples, wherein the statistically significant change is assumed when the change reaches or exceeds x times the standard deviation of the fourth plurality of samples, or wherein the determined value is the mean or median of the fourth plurality of samples plus or minus x times the width of the fluctuation or scatter within the fourth plurality of samples, or wherein the determined range of values ​​exceeds 2 times the width of the fluctuation or scatter within the fourth plurality of samples, where x is between 0.4 and 5, and / or wherein samples of the fifth plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object are used as the fourth plurality of samples, and the fourth plurality of samples of the fifth plurality of transmitted symbols and / or chips are selected so that its samples are selected at symbols and / or chips transmitted at different times and are at at least five different second time points in the symbol and / or chip period, the second time points being respectively deviated from at least two percent of the symbol and / or chip period and / or respectively frame-shifted from at least ten percent of the symbol and / or chip period, The spacing between the second time points in the symbol and / or chip period is smaller than the minimum feasible sampling interval of the second object of the transmission system.

3. A method according to claim 1 or 2, wherein the fourth plurality of samples of the fifth plurality of transmitted symbols and / or code chips are located in a portion of the symbol and / or code chip period, for which the at least one first analog signal and / or the at least one second analog signal is constant and / or has a constant level.

4. A method according to claim 2, wherein in order to determine the change, significance level, width of fluctuation or scatter, and / or predetermined value and / or value range, the level and / or amplitude and / or phase of the first analog signal or the second analog signal is used, and / or the change in the level and / or amplitude and / or phase of the first analog signal and / or the second analog signal received is used as the change in the first analog signal or the second analog signal received or a sample thereof.

5. A method according to claim 1 or 2, wherein the second analog signal is generated from the first analog signal by mixing with a high frequency, and / or the frequency of the second analog signal is higher than the first analog signal, and / or wherein the first analog signal is reconstructed at the second object from the second analog signal at the second object by mixing before sampling.

6. A method according to claim 2, wherein the second multiple is equal to the fourth multiple, and / or the third multiple transmitted symbols and / or code chips are equal to the fifth multiple transmitted symbols and / or code chips, and / or wherein the first time point and the second time point are selected so that the first time point is in a first time span of the symbol and / or code chip period and the second time point is in a second time span, and the first time span and the second time span do not overlap.

7. The method according to claim 1 or 2, wherein the transmission system is bidirectional and the method is applied to both transmission directions.

8. A method according to claim 1 or 2, wherein the symbols and / or code chips transmit at least partially encrypted information, and / or inferences about the process of the first analog signal and / or the second analog signal, and wherein such inferences are derived and used at the second object to select one or more of a plurality of numbers, and / or to define one or more time periods, segments and / or time points.

9. A method according to claim 2, wherein the second and / or fourth plurality of samples are equidistant in the symbol and / or code chip period, and / or wherein the second and / or fourth plurality of samples are equidistant over time, wherein their spacing is selected in the course of time so that their positions in the symbol and / or code chip period are repeated at the earliest after five symbols and / or code chips and / or wherein the symbol and / or code chip period is divided into at least three non-overlapping time ranges, wherein the first time point is in a first range of the three ranges and the second time point is in a second range of the three ranges.

10. The method according to claim 1 or 2, wherein the synchronization accuracy between the first object and the second object in the transmission system is selected so that the deviation between the first object and the second object is at most 50% of the symbol and / or code chip period.

11. A method for detecting and / or protecting against relay attacks, wherein the earliest reception of a signal change and / or a signal edge is determined using a method according to one of the preceding claims, and a. when a predetermined time deviation between the data reception time and the earliest reception time is exceeded, and / or when there is a deviation between the earliest reception and a predetermined time window or a time window calculated by other methods, and / or b. in the case of exceeding the signal transmission time and / or signal round-trip transmission time and / or distance determined based on the time point of the earliest reception, and / or c. in the event of a predetermined deviation from the signal transmission time and / or the signal round-trip transmission time and / or the distance determined in other ways or by other methods, Measures for defending against relay attacks are taken, and / or by means of received signals, instructions and / or verifications, the initiation of a relay attack is not performed and / or is not recognized as valid.

12. A method for protecting an access system comprising an authorization device and an access control device, wherein between the authorization device and the access control device, at least one first plurality of symbols and / or chips are transmitted in an encoded manner in at least one first analog signal at a first symbol or chip rate from the first of the authorization device and the access control device to the second of the authorization device and the access control device by means of a transmission system in an electrically, magnetically or electromagnetic manner, and / or in at least one second analog signal generated based on the first analog signal from the first of the authorization device and the access control device to the second of the authorization device and the access control device, The earliest reception time of a signal change and / or a signal edge is determined by a method according to one of the above claims 1 to 10, and if a predetermined time deviation between the time of data reception and the time of the earliest reception is exceeded and / or if there is a deviation between the earliest reception and a time window that is predetermined or calculated by other methods, access, entry, activation and / or opening is denied by the access control device, and / or A signal transmission time and / or a signal round-trip transmission time and / or a distance are determined based on the earliest received time point, and access, entry, activation and / or opening are denied by the access control device if a predetermined signal transmission time and / or a predetermined signal round-trip transmission time and / or a predetermined distance is exceeded and / or if a predetermined deviation of the signal transmission time and / or the signal round-trip transmission time and / or the distance determined in other ways or by other methods is exceeded.

13. An access control system having an authorization device and an access control device, wherein the access control system has a transmission system, which is designed to: transmit at least one first plurality of symbols and / or chips between the authorization device and the access control device in an encoded manner at a first symbol rate or chip rate in at least one first analog signal from a first one of the authorization device and the access control device to a second one of the authorization device and the access control device, and / or transmit at least one second analog signal generated based on the first analog signal from a first one of the authorization device and the access control device to a second one of the authorization device and the access control device, The access control system is designed to: determine the earliest received time of a signal change and / or a signal edge by means of a method according to one of the above claims 1 to 10, and deny access, entry, activation and / or opening if a predetermined time deviation between the time of data reception and the earliest received time is exceeded and / or if there is a deviation between the earliest received time and a time window that is predetermined or calculated by other methods, and / or The signal transmission time and / or the signal round-trip transmission time and / or the distance are determined based on the earliest received time point, and access, entry, activation and / or opening are denied if a predetermined signal transmission time and / or a predetermined signal round-trip transmission time and / or a predetermined distance are exceeded and / or if a predetermined deviation of the signal transmission time and / or the signal round-trip transmission time and / or the distance determined in other ways or with the aid of other methods or devices is exceeded.

14. A method of using the earliest received time point of a signal change and / or a signal edge for access control, authentication, distance measurement, synchronization and / or for detecting and / or for protecting against relay tools, wherein at least one first plurality of symbols and / or chips are transmitted in an encoded manner from a first object to a second object in at least one first analog signal at a first symbol or chip rate, and / or from the first object to the second object in at least one second analog signal generated based on the first analog signal, by means of a transmission system, and the at least one first analog signal or the at least one second analog signal at the second object is transmitted in an encoded manner. a second plurality of samples of symbols and / or chips for detecting the earliest reception of a signal change and / or a signal edge of a symbol or chip relative to a previous symbol or chip change, wherein the time point of the earliest reception is selected as a time point at which there is an earliest sample of the second plurality of samples or an earliest aggregated group of samples from the second plurality of samples, the earliest sample or the earliest aggregated group showing a statistically significant change and / or exceeding or falling below a value determined from a fourth plurality of samples of the first and / or second analog signal or departing from a range of values ​​determined from the fourth plurality of samples of the first and / or second analog signal, wherein the second plurality of samples of the third plurality of transmitted symbols and / or chips are selected so that the samples are selected at symbols and / or chips transmitted at different times and are located at at least five different first time points in the symbol and / or chip period, the first time points are respectively deviated from at least 2 percent of the symbol and / or chip period, and / or are respectively frame-shifted to at least 10 percent of the symbol and / or chip period, wherein the spacing between the first time points in the symbol and / or chip period is less than the minimum feasible sampling interval of the second object of the transmission system, Therein samples of a fifth plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object are used as the fourth plurality of samples.

15. A transmission system comprising at least two objects, each of which has at least one antenna and a total of at least one transmitter and receiver and a computing and / or control unit and at least one memory, and the transmission system is designed to: transmit at least one first plurality of symbols and / or chips at a first symbol or chip rate in at least one first analog signal in an encoded manner from a first object of the two objects to a second object of the two objects and / or in at least one second analog signal generated based on the first analog signal from the first object of the two objects to the second object of the two objects, and the transmission system is designed to determine the earliest reception time of a signal change and / or a signal edge in a synchronous symbolic and / or digital transmission system, It is characterized in that The system is designed to use a second plurality of samples of a third plurality of transmitted symbols and / or chips of the at least one first analog signal or the at least one second analog signal at the second object to detect the earliest reception of a signal change and / or a signal edge of a symbol or chip that is offset from a previous symbol or chip, wherein the time point at which the earliest sample of the second plurality of samples or the earliest aggregated group from the second plurality of samples exists, the earliest sample or the earliest aggregated group showing a statistically significant change, and / or the earliest sample of the second plurality of samples or the earliest aggregated group from the second plurality of samples exists, the earliest sample or the earliest aggregated group exceeding or falling below a value determined from a fourth plurality of samples of the first and / or second analog signal, or departing from a range of values ​​determined from a fourth plurality of samples of the first and / or second analog signal is selected as the time point of the earliest reception, wherein the second plurality of samples of the third plurality of transmitted symbols and / or chips are selected so that the samples are selected at symbols and / or chips transmitted at different times and are located at at least five different first time points in the symbol and / or chip period, the first time points are respectively deviated from at least two percent of the symbol and / or chip period and / or are respectively frame-shifted to at least ten percent of the symbol and / or chip period, wherein the spacing between the first time points in the symbol and / or chip period is less than the minimum feasible sampling interval of the second object of the transmission system, Therein samples of a fifth plurality of transmitted symbols and / or chips of the at least one first analog signal or the second analog signal at the second object are used as the fourth plurality of samples.

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