Method for localisation relative to an anchor network by means of unidirectional communication

Abstract

The invention relates to locating an active or passive radio node relative to a network of at least two anchors. This can be achieved, in particular, by dispensing with time synchronisation between the anchors (A1, A2) and the radio node (FK) while the anchors are time synchronised with each other. In addition, one-way ranging can further reduce the required communication. It is sufficient, if a one-way transmission with frequency change is carried out from the radio node to at least two anchors, or from at least two anchors to the radio node. In contrast to the known one-way ranging between an active and a passive object, time synchronisation between active and passive objects can be dispensed with if either two time-synchronised active objects or one active and two time-synchronised passive objects are used.

Description

[0001] Method for localization relative to an anchor network using unidirectional communication

[0002] The application concerns the location of an active or passive radio node against a network of at least two anchors. It also concerns the synchronization of frequencies and times of two objects, such as anchors.

[0003] Such systems are known in various ways, for example as GPS or from W0202209651 5A1 and EP 2710398 B1 .

[0004] Unilateral distance determination is also known, for example, from WO 2022 096 091 A1.

[0005] The object of the present invention is first and foremost to make such methods simpler, more reliable, more flexible and / or faster. This can be achieved in particular by dispensing with time synchronization between the anchors and the radio node, while the anchors are time synchronized with each other. In addition, the necessary communication can be further reduced through one-sided ranging. It is sufficient if a one-sided transmission with frequency change is carried out from the radio node to at least two anchors or from at least two anchors to the radio node. In contrast to the known one-sided ranging between an active and a passive object, time synchronization between active and passive objects can be dispensed with if either two time-synchronized active objects or one active and two time-synchronized passive objects are used.This object is achieved by a method, an anchor network, and an anchor network together with at least one, in particular a plurality of, active and / or passive radio nodes configured to carry out the method. For this purpose, each anchor and each radio node has, in particular, a control unit and a transmitting and / or receiving device.

[0006] The method according to the invention is one for determining a position and / or a direction and / or a distance difference of an active and / or passive radio node at least relative to an anchor network comprising at least two anchors, wherein the at least two anchors are time-synchronized with each other or with a common timer. The method is applied in particular indoors, at distances between anchor and radio node of less than two kilometers, in particular less than 200 m, and / or when the radio channel properties remain approximately unchanged during the implementation of the method or at least during the signal propagation time of a signal between anchor and radio node.The method is particularly advantageously applied to a large number of radio nodes, in particular more than 20 radio nodes, and / or used to track a large number of radio nodes and / or applied to a large number of anchors, in particular at least five, in particular a large number of anchor pairs. For this purpose, it is particularly preferred to carry out the method using passive radio nodes, in particular pairs of radio nodes. Passive radio nodes are understood to be those that do not transmit signals for distance or distance difference measurement. This does not mean that the radio nodes do not, for example, transmit measurement results wirelessly and / or communicate for other purposes. For example, a mobile phone that passively locates itself relative to the anchor network, as is the case with GPS positioning, for example, but maintains a data connection for receiving and sending user data, would be passive in this sense.

[0007] According to the invention, the radio node and / or the at least two anchors of the anchor network each transmit radio positioning signals, alternating between at least two, in particular between at least five, frequencies, whereby the phase relationship of the signals before and after a change is known. This can be achieved by measuring the relationship or by other means through which the relationship is known. For example, switching can be performed without a phase jump.

[0008] According to the invention, the direction, position and / or a distance difference is determined, in particular exclusively, on the basis of

[0009] - measured phase or phase and amplitude of received radio location signals and

[0010] - the known phase relationship and

[0011] - Information on the time offset of the frequency changes between the anchors as well as on the frequencies and, depending on the design of the method, additional information on at least the relative position and / or the distance between the at least two anchors of the anchor network.

[0012] What's special about this is that even without time synchronization between the radio nodes on one side and the anchor network on the other, it is possible to determine the distance difference between the radio nodes and the individual anchors, even with only unidirectional signal exchange between the radio nodes on one side and the anchor network on the other. This enables not only passive radio nodes, but also simultaneous determination with respect to and / or by many radio nodes, as well as short measurement times.

[0013] From the distance differences, together with other information such as the distance between the anchors, further information such as the direction to the radio node, distance and / or position of the radio node can be determined. The determinations can be made in the anchor network, in the radio node and / or an external processing unit. The anchors can, for example, transmit their signals on the frequencies f1,1 to f1,n for anchor 1 with frequencies 1 to n and analogously for the other x anchors, i.e. f1,1 to fx,n. The frequencies 1 to n of the anchors can be at least approximately identical, so that one can briefly and approximately speak of the frequencies f1 to fn. Approximately identical frequencies exist in particular when they are considered identical due to the existing synchronization, their deviation is no greater than the current CFO and / or their difference does not exceed 100 MHz.

[0014] The armatures can switch between the frequencies at times t1,2 to tx,n, where t1,2 means the switching of armature 1 from the first to the second frequency.

[0015] Absolute times are not important, but can be given relative to any time, for example in the anchor network, to which the radio node does not need to be synchronized.

[0016] However, alternatively or additionally, the radio node can also transmit signals on the frequencies f1 to fn.

[0017] The radio node can switch between the frequencies at times t1,2 to t1,n, where t1,2 means the switching of the radio node 1 from the first to the second frequency.

[0018] Absolute times are not important, but can be given relative to any time, for example in the radio node, to which the anchor network does not need to be synchronized.

[0019] The transmission of signals at different frequencies, as well as the switching, can occur with or without interruptions. It is only important that the phase position of the signals relative to each other before and after the switching is known. This requires information about the time of a switchover, possibly a virtual one, and the relative phase position before and after the switching. The same physical sequence, with transmission with interruptions during the switching, can thus be specified with different combinations of relative phase position and switching time (within the interruption).

[0020] When the radio node transmits, the anchors are receivers; when the anchors transmit, the radio node is the receiver. The receiver(s) receive the signals at different frequencies and measure their phase position or their amplitude and phase position. The phase positions can be designated, for example, as phi1,1 to phix,n. When the anchors transmit, the radio node measures the signals of anchors 1 to x at their respective frequencies 1 to n; when the radio node transmits, the anchors 1 to x measure the signals of the radio node at frequencies 1 to n.

[0021] The calculation can be done, for example, as follows:

[0022] 1 . Calculate the distance between anchor 1 and radio node as if both were synchronized in time.

[0023] 2. Calculate the distance between anchor 2 and radio node as if both were time synchronized.

[0024] 3. Calculate the distance difference, eliminating the "unknown" time difference.

[0025] In multipathing environments, the shortest signal path (the shortest distance detectable in the signal) can advantageously be searched for using FFT and / or high-resolution methods such as MUSIC or CAPON. These shortest distances are then subtracted. For this purpose, the signal components of the shortest path between an anchor and the radio node are isolated using FFT and / or high-resolution methods, and the respective distance is determined based on this.

[0026] It is also possible to determine an angle, i.e. a relative orientation, of the radio node to the connecting line between two anchors.

[0027] The problem is also solved by an anchor network comprising at least two anchors, wherein the at least two anchors are time-synchronized with each other or with a common timer. The anchors have, in particular, means for receiving and / or transmitting radio signals. The anchor network further has at least one control unit configured to control the anchors to carry out the method, in particular the anchor-side part.

[0028] The problem is also solved by a system comprising an anchor network and at least one, in particular a plurality of, radio nodes. The radio node(s) in particular have means for receiving and / or transmitting radio signals. The radio node(s) further each have at least one control unit configured to control the respective radio node to carry out the part of the method, in particular the part of the method at the radio node.

[0029] Furthermore, the anchor network or system preferably comprises a computing unit for determining the position and / or direction and / or distance difference. The computing unit can be part of the anchor and / or the radio node.

[0030] In particular, the anchors are approximately or completely stationary, at least for the duration of the signal exchange, in order to determine a distance difference. This can be achieved, for example, by fixing the anchors to fixed structures or by placing them on fixed structures. However, holding them steady in human hands can also adequately meet the requirement. In particular, the consistency of the measurement can also be determined by the anchors determining their distances and / or positions before and after the signal exchange and comparing them. A metric can be determined for the accuracy or consistency, for example, based on the deviations in the distances and / or positions before and after the signal exchange.

[0031] Preferably, a channel analysis is performed on the received signals to determine the position, direction, and / or distance difference in order to determine the signal component of the shortest signal path assumed based on the channel analysis. In particular, the phase and / or amplitude measurement is used, in particular, only for this signal component. The channel analysis can be performed, for example, using an FFT, whereby the first relevant maximum is sought in the obtained pseudospectrum and assumed to be the shortest signal path.

[0032] It is particularly advantageous to use the change in phase shift during a frequency change or its ratio to the frequency difference of the frequency change to determine the position, direction, and / or distance difference. Therefore, the absolute phase position is not required.

[0033] Preferably, the time difference between the radio node and the anchor network is not determined and / or is unknown, at least not with an accuracy of at least 50 ns, and / or the relative time between the anchor network and the radio node is not used to determine the position and / or direction. While it is not an advantage that (precise) time synchronization is not available, it is a significant advantage to be able to do without it.

[0034] A time shift will be present in all measurements between the anchor network and the radio node and will thus cancel out when determining the distance difference. A drift in this time shift due to clocks / quartz frequencies of different speeds in the radio node and the anchor network can also be detected and corrected. It is preferred if the signals for determining a distance difference are exchanged within a time window that is so small that the (relative) drift of the clocks in the anchor network and the radio node is approximately constant and / or the error resulting from the change in the drift is, in particular, less than 3 ns, and in particular less than 0.3 ns, within the time window.

[0035] Time synchronization within the anchor network can be achieved in various ways. Synchronization is possible solely among the anchors or against another timer. This can be done via wired or wireless communication. In a preferred embodiment, depending on the application, time synchronization between the anchors of the anchor network is performed wirelessly, in particular by determining differences in phase shifts or phase shifts and amplitudes on the forward and / or return path of the transmission between two anchors, in particular also by means of in-line phase return of the negated measured phase.For distance determination, it is known to work with in-line phase return, i.e. to use the measured phase of a received signal and to modify the phase of the response signal sent in response based on the measured phase. This is done by adding the measured phase to a predetermined phase position and sending the response signal with the phase position obtained by this addition. From US 8,446,254 B2, for example, it is known to send back the response signal with exactly the phase of the received interrogation signal, but this still has the disadvantage that temporal information is missing. This can also be seen as a corresponding in-line phase return, in which, for example, the received phase of the interrogation signal is always added to the phase zero for the transmission of the response signal. If the predetermined phase were not zero here, but that of a PLL whose phase position relative to the common time is known, this would bring further advantages.

[0036] For time synchronization and / or determination of a deviation between timers, but alternatively or additionally also for frequency synchronization and / or determination of a frequency deviation of local PLLs of the objects, this method also works independently as a separate invention between two objects (e.g. first and second anchor) with a known phase relationship of the transmitted signals and / or PLLs, in particular in each case relative to the respective local timer of the two objects, preferably also with an in-line phase return, wherein addition is replaced by subtraction. This enables particularly fast execution of the synchronization and / or determination, in particular when the distance and / or the radio signal path length(s) between the two objects is known.Preferably, the transmitted radio signal is broken down into signal path components, and for the subsequent determinations, one or more signal path components are always considered separately, in particular one or more whose radio signal path length is known. Alternatively or additionally, known methods can be used to attempt to reduce multipathing, for example, by appropriately selecting frequencies.

[0037] For example, if the phase positions relative to the local clocks of the two objects are known—that is, the phase position of the PLL or the transmitted signals of the first object relative to the clock on the first object, and the phase position of the PLL or the transmitted signals of the second object relative to the clock on the second object—the synchronization of the two clocks can be achieved quickly and easily using in-line phase return. This also allows the frequency deviation of the PLLs of the two objects to be determined.

[0038] The frequency deviation of the PLLs of the two objects (CFO crystal frequency offset), which can be used directly for frequency synchronization, can be determined, for example, using the following procedure:

[0039] CFO = 1 / 2* dPhase(t2,t1 ) / (2*Pi) / (t2-t1 ), where dPhase(t2,t1 ) is the measured change between the phase shifts of two response signals from the second object, the second object having sent these two response signals to the signals sent to the first object at time t1 and time t2 of the timer on the first object (one to the one sent at time t1 and one to the one sent at time t2), and these two response signals being received at the first object, and the second object having already subtracted the phase of the signals sent at times t1 and t2, previously received, from the phase position known per se relative to the timer of the second object when sending the response signals. The phase shift is the phase shift caused by the radio channel and / or the transmission of the signals during the round trip (one signal from the first object to the second and from the second to the first).The change in phase shift is then understood to mean the change in phase shift from the first (starting at t1) to the second (starting at t2) round trip.

[0040] A longer time interval between the round trips and / or t1 and t2 results in greater accuracy and is therefore preferable. It is important to ensure the uniqueness at (2 * Pi) / 2. Depending on how precisely the CFO was known prior to the measurement, the time interval can be optimized so that it is large but uniqueness is still maintained. In practice, particularly with an existing CFO of 100 Hz or better (lower), time intervals between t1 and t2 or the round trips in the range of 0.3 to 50 ms have proven to be effective. Preferably, further measurements with increasing time intervals are subsequently performed, taking into account the accuracies achieved on the basis of the previous measurement(s), in order to set the time intervals so that uniqueness is maintained.

[0041] Preferably, the frequencies of the signals transmitted at time t1 and time t2 of the timer on the first object are selected to be identical, and the frequencies of the response signals of the second object to the signal transmitted at time t1 and to the signal transmitted at time t2 of the timer on the first object are also selected to be identical, in particular approximately identical to the frequencies of the signals transmitted at time t1 and time t2 of the timer on the first object. This means that they were aligned as closely as possible with the available information.

[0042] With sufficient time synchronization accuracy and a known distance and / or signal path length, the method can also be performed unidirectionally, even with only one signal at a single frequency. If a signal with a certain frequency and a known phase position is emitted at the first object at a known time, the expected phase position at the second object can be calculated. If the actual phase position is measured, the CFO can be calculated from this. However, all errors related to the signal path length, time synchronization, and phase measurement directly influence the determination of the CFO.

[0043] The method is preferably repeated at several different frequencies (e.g. fa and fb) at different times (e.g. ta for the start of execution at fa and tb for the start of execution at frequency fb; t1 is then in particular equal to ta in each case). Preferably, the frequencies have no linear distances from the time of execution (e.g. ta and tb) or only a low linear dependence, in particular of less than 10%. A low linear dependence is given in particular when the two-dimensional vectors, each consisting of frequency and transmission time, have a linear component of less than 10% to one another. This is the case, for example, in pairs between two such vectors if the projection of one onto the other has a length of less than 10% of the length of one.

[0044] Thus, especially with fb - fa = Kab * (tb - ta) for different pairs of fa and fb, Kab is not the same for all pairs, but in particular, it is different for all pairs. In another preferred, but technically more complex embodiment, the implementation is carried out at multiple frequencies simultaneously.

[0045] The time difference (dT), which can then be used directly for synchronization, can be determined using the following calculation: dT = 1 / 2* dPhase(f2,f1 ) / (2*Pi) / (f2-f 1 ), where dPhase is the measured change between the phase shifts of two response signals from the second object, where the second object has sent these two response signals to the signals sent from the first object with the frequency f1 and frequency f2 (first signal at f 1 , second signal at f2) and these two response signals (one to the one at f1 with approximately also frequency f1 and one to the one at f2 with also approximately frequency f 2) were received at the first object and where the second object, when sending the response signals, has already subtracted the phase of the signals sent from the first object previously received from the phase position known per se relative to the timer of the second object, i.e. in particular has rotated the transmitted phase of the response signals by the negative received phase of the previously received signal.A response signal is the response signal sent to the signal sent with frequency f1 and a reply signal is the response signal sent to the signal sent with frequency f2.

[0046] The measurement of the runout of the first signal at f1 and the corresponding

[0047] The measurement of the response signal and the concentricity of the second signal at f2 and the corresponding response signal are advantageously performed with a time interval during which the channel has not changed significantly, especially simultaneously. A CFO also leads to deviations if the measurements are not performed simultaneously. Although the deviation can be mathematically calculated with an approximately known CFO, it is advantageous to avoid or keep it small. In practice, a time interval of a maximum of 100 ms has proven effective.

[0048] Advantageously, signals for determining the frequency deviation and / or frequency synchronization are also used to determine the time difference and / or time synchronization, or vice versa. For this purpose, frequency hopping is used, in particular with non-equidistant frequency intervals and / or frequency intervals that are small or non-linear compared to the transmission time. In particular, this method is thus used for determining the frequency deviation and / or frequency synchronization on the one hand, and for determining the time difference and / or time synchronization on the other.

[0049] Preferably, the methods are repeated individually or jointly for several different frequency pairs (e.g., several pairs of fa and fb) at identical or different times (e.g., ta1 for the start of execution at fa 1 and fb 1, and ta2 for the start of execution at frequencies fa2 and fb2). Preferably, the frequencies and / or frequency differences exhibit little or no linear dependence on the time of execution.

[0050] It is therefore true, in particular with (fb 1 - fa 1 ) / (fb2 - fa2) = K12 * (ta1 - ta2) for different pairs of pairs fan / fbn and fam / fbm, that Knm is not the same for all, in particular it is different for all pairs of pairs.

[0051] In another preferred, but technically more sophisticated embodiment, the implementation is carried out for several pairs of frequency pairs simultaneously.

[0052] In a preferred embodiment, the radio signal exchange between the anchors for time synchronization occurs in a manner that allows for rapid switching between the transmission frequencies, particularly relative to the time required to turn the transmission amplifier on and off, such that first one object (e.g., the first anchor) transmits, particularly sequentially, on different frequencies, and then another object (e.g., the second anchor) transmits, particularly sequentially, on different frequencies. This allows the required time to be reduced.

[0053] In another preferred embodiment, the radio signal exchange between the objects for time synchronization occurs in which a slow switching between the transmission frequencies is provided, particularly in relation to the time required for switching the transmission amplifier on and off, so that the objects transmit only one signal at a time on one frequency, thus always alternating. This can reduce the required time.

[0054] In a further preferred embodiment in which the, in particular ongoing, time synchronization of the objects / anchors, in particular after an initial (possibly also arbitrary) time synchronization, with and / or during an approximately constant radio channel (reference channel) (e.g. if the average distance of the transmitted energy of the radio channel changes by less than 1 m, in particular by less than 10 cm, during and / or during the time synchronization and / or the time synchronization is carried out in such a way that this condition is met) between the anchors can be carried out radio-based, this is preferably carried out in such a way that the, in particular ongoing, time synchronization takes place between two anchors, in particular multiple times and continuously, by means of unidirectional signal exchange on several frequencies and on the basis of phase measurements on the exchanged unidirectional signals.

[0055] This can be done, for example, using the following calculation:

[0056] If dPh(F2,F1 ) is the relative (i.e. normalized to the difference of the frequencies F1 and F2) change in the phase shift (caused by the transmission channel) between the two unidirectional signals at F1 and F2 measured on received unidirectional signals at frequencies F1 and F2, for example from the first to the second anchor, then let ddPh((F2,F1 ),t2, t1 ) be the relative phase shift difference, i.e. the phase shift measured at time t2 corrected for the effect of the transmission channel, i.e. ddPh((F2,F1 ),t2, t1 ) = dPh(F2,F1 )(t2) - dPh(F2,F1 )(t1 ) with dPh(F2,F1 )(t2) as dPh(F2,F1 ) of a signal at time t1 and dPh(F2,F1 )(t1 ) as dPh(F2,F1 ) of a signal sent or received at time t2, then ddPh() is proportional to the shift dT of the time base between the objects / anchors between times t1 and t2.

[0057] So the time shift dT can be calculated with: dT = ddPh((F2,F1 ),t2, t1 ) / (2*pi) / (F2-F1 )

[0058] For this purpose, the change in the measured phases, in particular phase shifts, is preferably considered, especially at a plurality of frequencies, with the "reference measurement" with known time synchronization (t1). By measuring at different frequencies, the spacing of which is preferably selected to be large, in particular in the range of 50 - 500 MHz, a particularly error-tolerant determination can be made, which in particular places lower demands on the CFO and the previously existing coarse time synchronization and yet quite reliably avoids the ambiguity problem because, so to speak, a virtual measurement is only taken at the difference frequency. For example, if the measurement is carried out in the 2.4 GHz band with the frequencies 2400 and 2480 MHz, the difference is only 80 MHz.Then 12ns corresponds to 360° phase rotation, so that with a phase measurement accuracy in the range of + / -3 to 6° a fairly good time synchronization can be achieved and this with only low requirements in terms of avoiding ambiguity problems regarding the phase position.

[0059] The rate of change of the time synchronization from time t1 to time t2 is then: ddT = dPh at time 2 - dPh at time 1 = ddPh((F2,F1),t2, t1) / (t2 - t1). ddPh((F2,F1),t2, t1) can also be replaced by an average of several ddPh((Fn,Fm),t2, t1) with several frequency pairs Fn,Fm. This can increase the accuracy. ddPh is therefore the change in the phase shift measured at the second object (previously adjusted for the phase shift caused by the transmission channel) between signals received at the second object that were transmitted at the first object at times t1 and t2.

[0060] With sufficient accuracy of the measurement setup, in particular a sufficiently well-known signal path length, a sufficiently small CFO, and sufficiently accurate phase measurement, the time deviation can also be easily determined using a unidirectional signal. If a signal with a known phase position is emitted from the first object at a given frequency and its phase position is determined at the second object, this can be compared with the expected phase position, and dT can be directly determined from the deviation. However, this requires high accuracy requirements, especially at high frequencies, to avoid ambiguity.

[0061] Sufficient accuracy is achieved when ambiguity in the phase measurement can be reliably avoided. This can be determined mathematically based on the frequency used.

[0062] In general, the frequencies used in this text are preferably above 2 GHz. This allows for high accuracy and allows the use of existing transmitters, such as Bluetooth, Wi-Fi, and / or mobile networks, such as LTE.

[0063] The distance between the anchors / objects and / or their relative position is advantageously determined using radio-based distance measurements between any two of the anchors / objects. This completely eliminates the need for other measurement methods, such as manual or light-based ones. This reduces the amount of equipment required. It also enables the quick and easy setup of, for example, ad hoc, anchor networks. This can be helpful in emergency situations, for example, to locate a radio node, such as a cell phone. In the event of the loss or burial of one of the people, a group of people, each carrying a radio node, such as a cell phone, can use the radio nodes of the remaining people to set up an anchor network, and the radio node of the lost or buried person can be located promptly.For this purpose and in general, the radio nodes can, for example, determine their relative position using GPS and / or radio-based distance measurement. After an initial determination, the position of some or all of the anchors can be adjusted in order to improve the determination in a subsequent implementation of the method. This enables precise positioning to be achieved very quickly and reliably. For this purpose, the position of the anchors is changed, in particular iteratively, so that they are arranged around the radio node to be located, in particular evenly. For this purpose, some or all of the anchors can move towards the approximate position between measurements, in particular from different sides, while maintaining a, in particular predetermined, minimum distance between the anchors of, for example, 2 m.

[0064] It is preferred if the armatures adjust the phase of the emitted signals based on a time difference between the armatures so that the signals from the armatures appear to be emitted coherently. In a simple embodiment, the armatures transmit their signals at times fixed relative to their respective local clocks; this leads to deviations due to drift even with time synchronization. However, known phase jumps during switching and different phase positions of the radiation from different armatures can also result in an armature system viewed from the outside appearing incoherent. This can be changed by slightly changing the switching times so that the armature system appears coherent from the outside, at least from a certain distance from each armature. This can then simplify the necessary calculations.

[0065] With particular advantage for easy installation, the anchors or some of them are part of, in particular, stationary loudspeakers and / or lamps and / or other electrical infrastructure installed or operated in buildings or rooms (also: sockets, switches, smoke detectors, etc.).

[0066] To improve the accuracy and robustness of the method, the radio node communicates with the at least two anchors via multiple antenna paths, and / or the anchors communicate with each other in pairs via multiple antenna paths. An antenna path is, in particular, the radio channel from a first transmitting antenna to a first receiving antenna. If, for example, two antennas, e.g., of an anchor, are used for reception and the signals received with them are evaluated separately, two antenna paths are used. If, for example, a second transmitting antenna, e.g., of the radio node, is also used, for example, later in time, and reception is carried out with both receiving antennas, four antenna paths are used.

[0067] In certain use cases, it is preferable to build the anchor network of mobile devices ad hoc, and for the anchors to first determine information about their relative positioning, especially repeatedly. This allows for a rapid, solid anchor network and determination. This is possible with active and / or passive radio nodes.

[0068] Generally, depending on the application, it is preferable to work with active and / or passive radio nodes. Passive radio nodes are advantageous, for example, when a large number of radio nodes are used simultaneously and / or the radio node(s) should remain anonymous and / or undetected. The use of active radio nodes can be advantageous when they should consume as little electrical power as possible, i.e., transmit only briefly and receive for a short time. Combining active and passive provisions for a radio node can utilize the advantages of both variants.

[0069] The following explanations explain the inventions purely by way of example using the purely schematic figures. The figures show:

[0070] Fig. 1 is an illustration of an anchor network and an active radio node; Fig. 2 is an illustration of an anchor network and a passive

[0071] Radio control and

[0072] Fig. 3 an illustration of time synchronization using in-line phase return.

[0073] Figure 1 shows an anchor network with two anchors A1, A2 with fixed positions and a known distance. The radio node FK transmits unidirectional signals, which are received by the anchors A1, A2. From this, the difference in the distances represented by double arrows is determined. If the method is performed with multiple anchors, for example, three or four, and their positions are known, the position of the radio node can be determined in two or three dimensions.

[0074] Figure 2 shows an anchor network with two anchors A1, A2 and a passive radio node FK, which receives the unidirectional signals from anchors A1, A2 and determines the difference in the distances represented by double arrows. If the method is performed with multiple anchors, for example, three or four, and their positions are known, the position of the radio node can be determined in two or three dimensions.

[0075] Figure 3 shows an illustration of time synchronization using in-line phase return between two objects A1, A2, which can be anchors of an anchor network. The objects each have local timers and each have a PLL, which are preferably set to approximately the same frequencies, the phase position of which is known in relation to the respective local timer of the object, but is assumed here for simplicity to be identical, and the phase of which for each anchor is shown at two times Ta, Td for object A1 and Tb, Tc for object A2 by pointers in a circle, the outer circle in each case. The pointers in the inner circles (A1 right, A2 left) show the phase of a signal. The arrows between the objects illustrate signals, the upper one a first from the first object A1 to the second object A2 and the lower one a second from the second object A2 to the first object A1.The first object sends a signal starting at time Ta with the phase position of the internal PLL, so the pointers are identical. This signal start is received at the second object at time Tb, with a phase position indicated by the top left pointer, while the internal PLL of the second object A2 has the phase indicated by the pointer in the top right. The second object starts sending the second signal at time Tc, which for the sake of simplicity has been assumed to be approximately equal to Tb. Without inline phase return, this signal would be sent with the phase of the PLL. For the in-line phase return, however, it is now rotated by the negated deviation of the received first signal from the PLL of the second object and thus starts sending with a different phase position, illustrated by the bottom left pointer in the second object.The first object receives the signal and determines the phase position of the signal's start relative to its own PLL. From this, combined with the phase of the first signal's start of transmission, it can determine the phase shift through the radio channel of the round trip.

[0076] If the distance is constant and known, the relative change in the objects' timers can be determined. If the distance is constant, the deviation of the objects' timers can be determined by repetition. The phase position determined at the first object for the second signal can be compared with the calculated phase position for synchronous timers. This allows the deviation of the timers to be determined.

Claims

Claims 1 . Method for determining a position and / or a direction and / or at least one distance difference of an active and / or passive radio node (FK) at least relative to an anchor network comprising at least two anchors (A1, A2), wherein the at least two anchors have a time synchronization with each other and / or with respect to a common timer and wherein the radio node and / or at least two anchors of the anchor network each transmit radio positioning signals and thereby alternate between at least two, in particular between at least five frequencies with a known phase relationship and wherein, in particular exclusively, on the basis of - measured phase or phase and amplitude of received radio location signals and - the known phase relationship and - Information on the time offset of the frequency changes between the anchors as well as on the frequencies that have at least one distance difference and / or together with Information on at least the relative position and / or the distance between at least two anchors of the anchor network is used to determine the direction and / or position.

2. Method according to the preceding claim 1, wherein the radio node transmits positioning radio signals and the at least two anchors receive the positioning radio signals and measure their phase or phase and amplitude.

3. Method according to one of the preceding claims, wherein the at least two anchors transmit radio locating signals and the radio node transmits the Receives radio location signals and measures their phases or phases and amplitudes.

4. Method according to one of the preceding claims, wherein the change in the phase shift during a frequency change or its ratio to the frequency difference is used as the measured phase of received radio locating signals.

5. Method according to one of the preceding claims, wherein the time difference between radio node and anchor network is not known, at least not with an accuracy of at least 50 ns and / or wherein the relative time between anchor network and radio node is not used to determine the position and / or direction 6. Method according to one of the preceding claims, wherein the time synchronization between the anchors of the anchor network is carried out radio-based, in particular by determining differences in the phase shifts or phase shifts and amplitudes on the forward and return path of the transmission between two anchors in each case, in particular also by means of in-line phase return, in particular of the negative measured phase and / or wherein the time synchronization of the anchors is carried out radio-based by means of bidirectional signal exchange and on the basis of phase measurements on the exchanged signals, in particular by means of negated in-line phase return.

7. Method according to one of the preceding claims, wherein the distance between the anchors and / or their relative position is determined by means of radio-based distance measurements between each two of the anchors.

8. A method according to any one of the preceding claims, wherein the armatures adjust the phase of the radiated signals so that the signals of the armatures appear to be radiated coherently.

9. Method according to the preceding claim, wherein the signal exchange takes place in such a way that first an anchor on different frequencies sends and then another anchor sends on different frequencies.

10. Method according to one of the preceding claims, wherein the time synchronization of the anchors at and / or during an approximately constant radio channel between the anchors is carried out radio-based by means of unidirectional signal exchange on several frequencies and on the basis of phase measurements on the exchanged signals. 1 1. Method according to one of the preceding claims, wherein the anchors are components of, in particular stationary, loudspeakers and / or lamps and / or other electrical infrastructure installed or operated in buildings or rooms.

12. Method according to one of the preceding claims, wherein the radio node communicates with the at least two anchors via a plurality of antenna paths and / or the anchors communicate with each other in pairs via a plurality of antenna paths.

13. Method according to one of the preceding claims, wherein the anchor network is constructed ad hoc from mobile devices and in particular the anchors first determine information on their relative arrangement.

14. Anchor network configured to carry out the method according to one of the preceding claims together with an active and / or passive radio node.

15. Method for time synchronization, frequency synchronization and / or determination of a time difference and / or frequency deviation between a first and a second object, wherein the objects each have at least one local clock and at least one PLL and the relative phase position of two signals by means of the PLL of an object is known in dependence on the time difference of the generation or emission of the two signals at one of the objects relative to its clock and / or the phase position of the PLL of each of the objects relative to its timer, whereby the time synchronization, frequency synchronization and / or detection between the objects is carried out radio-based by means of phase measurement(s).

16. The method according to claim 15, wherein the time synchronization and / or determination of the time difference is carried out by determining phase shift of the transmission of the outgoing signal from the first to the second object and the return signal from the second to the first object by means of in-line phase return.

17. The method according to claim 16, wherein the in-line phase return is realized in that the phase position of the return path signal is changed at the second object relative to a phase position known relative to the local clock of the second object, in particular the phase position of its PLL, by the negated measured phase of the forward path signal received at the second object.

18. The method of claim 16, wherein multiple forward and return path signals are exchanged with in-line phase return.

19. Method according to claim 15 to 17, wherein a time synchronization and / or determination of the time difference takes place and wherein the phase position of the second signal received at the first object is determined at the first object and together with the phase position of the first signal at the first object with respect to the PLL of the first object, in particular the difference in the phase positions, is used for time synchronization, in particular the change in the difference between two forward and return path signal pairs exchanged at different frequencies is used as a measure of the relative change of the local clocks, in particular as their relative change.

20. Method according to claim 15, wherein the time synchronization and / or determination of the time difference, in particular when the distance between the objects is known, is radio-based by means of unidirectional Signal exchange from the first to the second object, in particular on several frequencies, and on the basis of phase measurement(s) on the signal(s) received at the second object, in particular wherein the phase position of the unidirectional signal of the first object received at the second object is determined at the second object and the phase position of the first signal at the second object relative to the PLL of the second object, in particular the difference to a phase position mathematically expected for the same clocks, is used for time synchronization.

21. Method according to claim 20, wherein the method is carried out during and / or with an approximately unchanged radio channel or with an approximately known radio channel, distance and / or approximately known signal path length.

22. Method according to claim 20 or 21, wherein the relative difference, measured on received unidirectional signals at a first and a second frequency, i.e. normalized to the difference between the first and second frequency, of the phase shifts caused by the transmissions between the two unidirectional signals at the first and second frequency is used for time synchronization, in particular as a measure of the deviation of the local clocks, in particular multiplied by the proportionality factor two Pi as the deviation of the local clocks.

23. The method according to claim 15, wherein the frequency synchronization and / or determination of the frequency deviation is carried out by determining phase shift of the transmission of the outgoing signal from the first to the second object and the return signal from the second to the first object by means of in-line phase return.

24. Method according to claim 23, wherein the in-line phase return is realized by the phase position of the return path signal being offset by the negated measured value relative to a phase position known relative to the local clock of the second object, in particular the phase position of its PLL. Phase of the forward signal received at the second object is changed at the second object.

25. The method of claim 23, wherein multiple forward and return path signals are exchanged with in-line phase return.

26. Method according to claim 23 to 25, wherein the phase position of the second signal received at the first object is determined at the first object and is used together with the phase position of the first signal at the first object relative to the PLL of the first object, in particular the difference in the phase positions, for frequency synchronization and / or determination, in particular the change in the difference between two forward and return path signal pairs exchanged at different times and in particular at at least approximately identical frequencies is used as a measure of the frequency deviation.

27. The method according to claim 15, wherein the frequency synchronization and / or determination of the frequency deviation, in particular with knowledge of the relative movement, in particular standstill, between the objects, is carried out radio-based by means of unidirectional signal exchange from the first to the second object, in particular at several times, and on the basis of phase measurement(s) of the signal tone(s) received at the second object.

28. Method according to one of claims 15 to 27, wherein the method is carried out during and / or with an approximately unchanged radio channel or with an approximately known radio channel, distance and / or approximately known signal path length.

29. Method according to claim 27 or 28, wherein the relative difference of the phase shifts caused by the transmissions between the two unidirectional signals measured at two different times on received unidirectional signals, i.e. first and second time, i.e. normalized to the difference between the first and second times, at the first and second time as a measure of the deviation of the PLLs of the two objects, in particular as the deviation of the local PLLs of the objects.

30. Method according to claim 27 or 28, wherein the phase position of the unidirectional signal of the first object received at the second object is determined at the second object and the phase position of the first signal at the second object relative to the PLL of the second object, in particular the difference to a phase position mathematically expected at the same frequencies of the PLLs of the two objects, is used for time synchronization.

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