SYSTEM AND METHOD FOR POSITIONING IN A BUILDING

Description

[0001] The technology described here generally relates to a building system. Embodiments of the technology particularly relate to a building system with which a user's position in a building can be determined, and to a method for operating such a system.

[0002] Building systems can be designed in a variety of ways for a wide variety of applications. For example, there may be an interest in determining a user's position in a building. This interest may be on the part of the user, who wants to orient themselves within the building. This interest may also exist on the part of building management, which wants to know whether and where a user is in the building. The well-known Global Positioning System (GPS) can generally be used to determine a position and for navigation. However, GPS reception in buildings is reduced or even impossible. Building systems with alternative approaches to positioning are therefore known for buildings. For example, DE 10 2013 201873 A1 discloses an indoor positioning system that uses RFID technology or NFC (Near Field Communication) technology to create radio cells within the building.

[0003] The building management's interest in knowing whether and where a user is in the building also exists in connection with an access control system, which is also an example of a building system. The access control system controls, for example, access to a restricted area (e.g., individual rooms or floors, or floor corridors with access to elevators). In such an access control system, users (persons) can identify themselves as authorized to access in various ways, e.g., with a key, a magnetic, chip, or RFID card, or a mobile electronic device (e.g., a mobile phone). WO 2010 / 112586 A1 describes an access control system in which a mobile phone carried by a user sends an identification code to an access node. If the identification code is recognized as valid, the access node sends an access code to the mobile phone, which displays the access code on a display.

[0004] If the user holds the mobile phone up to a camera so that the camera can capture the displayed access code, the access control system checks whether the captured access code is valid. If it is, the user is granted access.

[0005] WO 2018 / 183571 A1 describes a method in connection with multipath propagation of radio signals in which a radio profile is recorded from a known RFID tag as a function of a reception angle. A radio profile is also recorded from an unknown RFID tag as a function of a reception angle, which is then compared with the radio profile of the known tag. This allows the position of the unknown RFID tag to be determined.

[0006] US 2010 / 309051 A1 also concerns the multipath propagation of radio signals. Radio signals are used to calculate the position of a radio device in both indoor and outdoor environments. First, a moving scanner (e.g., a vehicle equipped with radio equipment) scans a geographic area of ​​interest and receives radio waves from various sources transmitting radio waves in different standards. The received signals are processed to characterize them and the transmission channels at each position of the vehicle.

[0007] WO2016 / 048370 A1 describes a system for determining the location of a mobile device. The system comprises a distributed antenna system, wherein signals propagated between the remote antenna units and a central unit are delayed so that different signal paths between the remote antenna units and the central unit have different delay times. The system determines the location of the mobile device using the delay times.

[0008] Multi-story buildings can experience high levels of foot traffic at certain times of the day, such as in the lobby of an office building in the morning or after a lunch break, when large numbers of employees enter the building and gather there to get to their workstations. At these times, not only the efficiency of an elevator system installed in the building is highly demanding, but also that of other building systems in the building in general. These systems aim to minimize long waiting times, disruption, and unrest in the lobby as much as possible, while maintaining a high level of safety. Therefore, there is a need for technology that meets these requirements while remaining user-friendly.

[0009] One aspect of such technology relates to a method for operating a building system according to claim 1, wherein the building system comprises a control device, transmission devices for primary radio signals, in particular a first transmission device for a first radio signal, a second transmission device for a second radio signal, a third transmission device for a third radio signal, a reception device for radio signals and a signal processing device communicatively connected to the reception device.In the method, primary channel impulse responses are determined by the signal processing device, wherein a first primary channel impulse response is based on the first radio signal received by the receiving device, wherein a second primary channel impulse response is based on the second radio signal received by the receiving device, and wherein a third primary channel impulse response is based on the third radio signal received by the receiving device. The signal processing device determines a secondary channel impulse response based on a secondary radio signal received by the receiving device, wherein the secondary radio signal is transmitted by a first mobile electronic device of a first user.The signal processing device also determines degrees of similarity by evaluating the channel impulse responses, with a first degree of similarity indicating how similar the first primary channel impulse response and the secondary channel impulse response are to one another, a second degree of similarity indicating how similar the second primary channel impulse response and the secondary channel impulse response are to one another, and a third degree of similarity indicating how similar the third primary channel impulse response and the secondary channel impulse response are to one another. For each degree of similarity, the signal processing device determines a distance between the mobile device and the transmitting device corresponding to the degree of similarity, which transmitting device is arranged at specified locations in the building. The signal processing device determines a position of the mobile device based on the distances.

[0010] Another aspect of the technology relates to a system for determining a user's position in a building according to claim 7. The system comprises a control device, transmission devices for primary radio signals, in particular a first transmission device for a first radio signal, a second transmission device for a second radio signal, and a third transmission device for a third radio signal, a reception device for radio signals, and a signal processing device communicatively connected to the reception device. The signal processing device determines primary channel impulse responses, wherein a first primary channel impulse response is based on the first radio signal received by the reception device, wherein a second primary channel impulse response is based on the second radio signal received by the reception device, and wherein a third primary channel impulse response is based on the third radio signal received by the reception device.The signal processing device also determines a secondary channel impulse response based on a secondary radio signal transmitted by a mobile device of a first user, received by the receiving device. The signal processing device further determines degrees of similarity by evaluating the channel impulse responses, wherein a first degree of similarity indicates how similar the first primary channel impulse response and the secondary channel impulse response are to one another, wherein a second degree of similarity indicates how similar the second primary channel impulse response and the secondary channel impulse response are to one another, and wherein a third degree of similarity indicates how similar the third primary channel impulse response and the secondary channel impulse response are to one another.The signal processing device also determines, for each degree of similarity, a distance between the mobile device and the transmitting device corresponding to the degree of similarity, which are located at specified locations in the building. Based on these distances, the position of the mobile device is determined.

[0011] The technology described here creates a building system that, based on the analysis of radio signals, not only detects that a user is in the building but also determines their position within the building. This is done in a convenient way for the user, because, for example, they don't have to handle their mobile electronic device. In addition to this perceptible advantage for the user, the technology described here also offers significant technical advantages.

[0012] In one embodiment, the position of the mobile device is determined using a trilateration method. This allows a known method of low complexity to be used for position determination.

[0013] According to the technology described here, the degrees of similarity are based on an evaluation of the channel impulse responses. From each of the primary channel impulse responses, a first sequence of temporally successive first multipath signal components is determined, and from the secondary channel impulse response, a second sequence of temporally successive second multipath signal components is determined. The evaluation of the primary and secondary channel impulse responses comprises a pairwise comparison, according to the order in the first and second sequence, of each second multipath signal component with its first multipath signal component corresponding to the order in order to determine a temporal deviation for each pair such that a maximum temporal deviation and a minimum temporal deviation are present, wherein the degree of similarity is based on at least one of these temporal deviations.The technology described here therefore specifically uses multipath signal propagation, which is often considered disadvantageous.

[0014] Because multipath signal propagation is specifically utilized, the technology described here can be used even when there is no line of sight to the receiving device. The technology described here is therefore also suitable for use in buildings with high user density. Such user density might occur, for example, in the lobby of an office building or hotel with high traffic volumes.

[0015] Another advantage of the technology described here is that it can be used for both synchronous and asynchronous radio signals. In one embodiment for a synchronous situation, the primary radio signals and the secondary radio signal share a common time reference. For each degree of similarity, the distance is calculated according to d = E S ⋅ c ⋅ SD S , where c is the speed of light, ES = (K + 1) / K (correction factor) and SD S = max { | Δ 1 | , ..., | Δ K |} (degree of similarity in a synchronous situation).

[0016] In one embodiment of an asynchronous situation, the primary radio signals and the secondary radio signal do not have a common time reference. For each of the similarity levels, the distance is calculated according to d 1 = E A ⋅ c / 2 ⋅ SD A , where c is the speed of light, EA = (K + 1) / (K - 1) (correction factor) and SD A = (max {Δ 1 , ..., Δ K} - min{Δ 1 , ..., Δ K}) (degree of similarity in an asynchronous situation).

[0017] As mentioned above, the technology described here can also be used with more than one user, for example, in high traffic situations. In such a situation, the receiving device receives a number of additional secondary radio signals transmitted by a number of additional mobile electronic devices. Based on each additional secondary radio signal received, a channel impulse response is determined, which is evaluated in conjunction with the primary channel impulse responses to determine the distances of the corresponding additional mobile electronic device to the transmitting devices. This allows the positions of the individual users to be detected even in situations with more than one user.

[0018] In one embodiment, the positions of the other mobile electronic devices are used to determine distances between the other users. Such inter-user distances can be used to detect exceptional situations in the building. Such an exceptional situation can occur if an authorized or unauthorized user attempts to join a user who, for example, is going through a lock in order to enter a restricted access zone. The technology described here can also be used to detect such a pushing situation. If such a situation occurs, a security measure can be initiated, e.g. triggering an alarm and / or alerting security personnel. In another exceptional situation, some or all of the users present may belong together and as such form a group. In this case, too, for example,Security personnel can be alerted to, for example, guide the users of this group through the entrance together in order to keep the group together and keep delays to a minimum.

[0019] Known standards for radio communication can be applied in the technology described herein. In one embodiment, the radio signals have a bandwidth of at least 500 MHz and are transmitted and received according to a WLAN / WiFi standard or a standard for ultra-wideband technology. Examples of such standards are given elsewhere in this description.

[0020] In one embodiment, a first identifier is used to determine the building action. If the first user is authorized to access the building, the first identifier is assigned to a user profile in which a user-specific building action is stored. The first identifier is determined in conjunction with the secondary radio signal. The building action can, for example, consist of initiating an elevator call (destination call) for the user or releasing doors or other barriers to which this user is authorized to access.

[0021] A further advantage of the technology described here is that the evaluation of the received primary and secondary radio signals takes place in the signal processing device, which, for example, acts as a central device for radio signal evaluation for the entire building, while the transmitting devices have a limited range of functions with low complexity. In one embodiment, the range of functions is restricted to periodic transmission of a broadband training sequence, possibly in conjunction with an identifier. The transmitting devices are therefore relatively inexpensive. If additional transmitting devices are to be installed in a zone, for example, to improve the accuracy of distance determination, this can also be achieved relatively inexpensively.

[0022] Another advantage is that the technology described here can be used in conjunction with an access control system. This essentially creates a hybrid building system that can be used in conjunction with positioning and / or access control. The position of a user determined with the technology described here can be used to determine their distance to the entrance to a restricted-access zone. If this distance is less than a specified minimum distance, it can mean that the user is not just in the public zone, but actually requests access. If there are multiple users in the public zone and their positions are determined, the user who actually requests access can be identified.

[0023] Various aspects of the improved technology are explained in more detail below using exemplary embodiments in conjunction with the figures. In the figures, like elements have like reference numerals. They show: Fig. 1 is a schematic representation of an exemplary situation in a building with a building system according to a first embodiment; Fig. 2 is a schematic representation of a second embodiment of a building system; Fig. 3A is a schematic representation of multipath signal propagation between components in the situation according to Fig. 1 can occur; Fig. 3B a schematic representation of an exemplary first channel impulse response based on a first radio signal; Fig. 3C a schematic representation of an exemplary second channel impulse response based on a second radio signal; Fig. 3D a schematic representation of the first channel impulse response with exemplary peak values; Fig. 3E a schematic representation of the second channel impulse response with exemplary peak values; Fig. 3F a schematic representation of a superposition of the Fig. 3D und 3E shown channel impulse responses; Fig. 4 is a flowchart of an embodiment of a method for determining a position of a user in a building, Fig. 5 is a flowchart of a further embodiment of a method for position determination and Fig. 6 is a schematic representation of an embodiment of a signal processing device of the Fig. 1 und Fig. 2 shown building system.

[0024] Fig. 1 und Fig. 2 are schematic representations of exemplary situations in a building with a building system 1. The building system 1 can, for example, comprise a system for determining a position of a user 2, an access control system, an elevator system, or a combination of these systems. In the Fig. 1 und Fig. 2 In the situations shown, an access control system is used, among other things, whereby in this application the position of the user 2 can also be determined according to the technology described here. The building system 1 is also referred to below as an access control system; embodiments of the technology described here are described with reference to an access control system. The person skilled in the art will recognize that the position determination can also be used in situations other than those described in Fig. 1 und Fig. 2 shown situations, in particular independently of an access control system or an elevator system, for example, a determined position can be communicated to the user 2 for orientation and / or route guidance.

[0025] In Fig. 1 und Fig. 2 For illustrative purposes, only some walls 3, rooms 18 and zones 20, 22 of the building are shown. The rooms 18 can be, for example, offices, apartments, halls and / or elevator cars of an elevator system. In the Fig. 1 In the situation shown, a user 2 (U 1 ) is located in zone 22, carrying a mobile electronic device 6 (hereinafter also referred to as mobile device 6). The mobile device 6 transmits a radio signal RF2. In the Fig. 2 In the situation shown, a large number of users 2 (U 1 , U 2 , U 3 , U 4 ) are located in zone 22. In these exemplary situations, zone 22 is not subject to any access restrictions and is hereinafter also referred to as public zone 22. An access 24 separates public zone 22 from zone 20, which is subject to access restrictions and borders rooms 18. Zone 20 is hereinafter also referred to as restricted-access zone 20. The term "building" in this description includes, for example, residential and / or commercial buildings, sports arenas, airports, and ships.

[0026] According to one exemplary embodiment, the building system 1 comprises a plurality of transmitting devices 4, 4.2, 4.3 (each represented as TX) for radio signals RF1, RF12, RF13. In the exemplary embodiment shown, the building system 1 comprises three transmitting devices 4, 4.2, 4.3, but more than three transmitting devices can also be arranged. The transmitting devices 4, 4.2, 4.3 are arranged at fixed positions in the building; they can, for example, be specified and documented in a building plan. Such documentation can, for example, specify for each of the transmitting devices 4, 4.2, 4.3 on which floor it is arranged and at which position. The position can, for example, be specified relative to a selected fixed point.

[0027] According to one exemplary embodiment, the building system 1 also comprises a receiving device 14 (shown as RX) for radio signals RF1, RF12, RF13, RF2, a signal processing device 8 (shown as DSP) connected to the receiving device 14, and a controller 11 (shown as ACS). The receiving device 14 and the signal processing device 8 can be arranged in an evaluation unit 12, which is connected to the controller 11 of the building system 1 via a wired and / or wireless connection 28.

[0028] In Fig. 2 is that in Fig. 1 The application example shown is modified in that it includes a further receiving device 14A. The receiving device 14A is connected to the signal processing device 8 of the evaluation unit 12 by means of a wired and / or wireless connection 27. The receiving device 14A is optional, but may be advantageous in the technology described here, as explained elsewhere in this description. Further components and functionalities of the building system 1 according to Fig. 1 und Fig. 2 are mentioned elsewhere in this description.

[0029] In the Fig. 1 und Fig. 2 In the situations shown, the technology described here can be advantageously used to operate the building system 1 with the least possible complexity. Briefly and by way of example, the operation of the building system 1 according to an embodiment is as follows: The technology determines a distance d 1 , d 12 , d 13 for each of the transmitting devices 4, 4.2, 4.3 (see Fig. 1 ) to user 2. Since the positions of the transmitting devices 4, 4.2, 4.3 in the building are fixed and therefore known, the technology determines the position of user 2 from these distances d 1 , d 12 , d 13 , for example using a trilateration method. To do this, the technology evaluates radio signals RF1, RF12, RF13, RF2 transmitted by the transmitting devices 4, 4.2, 4.3 and by the mobile device 6 of user 2 in order to obtain distinguishable channel impulse responses (h(τ)) based on these. Since the sources of these radio signals (i.e. the transmitting devices 4, 4.2, 4.3 and the mobile device 6) are relatively close to one another in the same environment (public zone 22), the radio signals propagate along similar paths (e.g. due to reflections from walls 3 and other effects). For this reason, the closer the mobile device 6 is to a particular transmitting device 4, 4.2, 4.3, the more similar are the channel impulse responses (h(τ)) assigned to this pair (mobile device 6, specific transmitting device 4, 4.2, 4.3). The technology described here uses this and determines a degree of similarity from the channel impulse responses (h(τ)) of each pair, which indicates how similar the respective channel impulse responses are. In total, there are at least three degrees of similarity. Each degree of similarity is used to determine the distance d 1 , d 12 , d 13 of the mobile device 6 to the specific transmitting device 4, 4.2, 4.3. The total of at least three distances d 1 , d 12 , d 13 are then used to determine the position.

[0030] The radio components of the building system 1 (i.e. the receiving devices 14, 14A and the transmitting devices 4, 4.2, 4.3) are arranged in the public zone 22 in the exemplary embodiments shown. The transmitting device 4 is arranged, for example, in the entrance 24 or in its vicinity, while the transmitting devices 4.2, 4.3 and the receiving devices 14, 14A are arranged at a distance therefrom at other locations in the public zone 22. In the situation shown, the user 2 staying there has a distance d 1 to the transmitting device 4, a distance d 12 to the transmitting device 4.2 and a distance d 13 to the transmitting device 4.3. The person skilled in the art will recognize that each further Fig. 2 shown user 2 (U 2 , U 3 , U 4 ) has corresponding distances to the transmitting devices 4, 4.2, 4.3; for illustration, Fig. 2 However, only distances d 2 , d 3 , d 4 of the other users 2 (U 2 , U 3 , U 4 ) to the transmitting device 4 and thus to the access 24 are shown.

[0031] The location of the receiving device 14 is selected such that it receives the radio signals RF1, RF12, RF13 transmitted by the transmitting devices 4, 4.2, 4.3 with sufficient signal strength, i.e., a radio signal has a signal strength (expressed, for example, by an RSSI (Received Signal Strength Indicator) value) at the location of the receiving device 14 that is greater than a threshold value specified for reliable reception. The location of the receiving device 14A is selected accordingly.

[0032] The following is an embodiment of the technology described here with reference to the Fig. 1 The situation shown is explained. In one exemplary embodiment, the transmitting devices 4, 4.2, 4.3 transmit the radio signals RF1, RF12, RF13, each of which has a relatively high bandwidth, for example, greater than approximately 500 MHz, for example between 1 GHz and 4 GHz. The bandwidth, characterized by a lower and an upper limit frequency, specifies the width of the intermediate frequency spectrum in which dominant frequency components of a signal to be transmitted lie. The transmitting devices 4, 4.2, 4.3 transmit the radio signals RF1, RF12, RF13 according to a radio communication standard designed for this bandwidth, for example, according to a (broadband) WLAN / WiFi standard (802.11ad) or a standard for ultra-wideband (ultra-wideband (UWB)) technology (IEEE 802.15.4a). The radio signals RF1, RF12, RF13 can also be transmitted according to the 5G standard or any other or future standard for broadband radio communication.

[0033] The properties and functions of the transmitting devices 4, 4.2, 4.3 are described below using the example of the transmitting device 4. Those skilled in the art will recognize that each additional transmitting device 4.2, 4.3 has essentially the same properties and functions.

[0034] In one embodiment, the transmitting device 4 generates and transmits a training sequence with the radio signal RF1, which is transmitted periodically or continuously. The training sequence consists of predefined bit patterns, so that the training sequence is characteristic of the transmitting device 4; this allows the radio signal RF1 to be distinguished from other radio signals (e.g., the radio signal RF2). In one embodiment, the radio signal RF1 can be assigned to the transmitting device 4 using the training sequence in a receiver. The training sequence can, for example, be an m-sequence (maximum length sequence), which can be generated, for example, using a shift register with a generator polynomial or using a computer program.

[0035] In one embodiment, the radio signal RF1 can be configured to transmit additional information in addition to the training sequence, for example, information about a location of the transmitting device 4 or a transmitter identifier assigned to the location in a database. The radio signal RF1 can also be provided to cause the mobile device 6 to transmit a response signal, for example, to place the response signal in a defined temporal relationship to the radio signal RF1; for example, the response signal has a temporal offset from the radio signal RF1.

[0036] The receiving device 14 is compatible with the radio communication standard according to which the transmitting devices 4, 4.2, 4.3 transmit. The receiving device 14 is also designed to receive the broadband radio signals RF1, RF12, RF13 and evaluate the training sequences. The receiving device 14 also receives the radio signal RF2 transmitted by the mobile device 6 of the user 2 if the user 2 or the mobile device 6 is within radio range of the receiving device 14.

[0037] The mobile device 6 has a radio module which, in one embodiment, generates and transmits the radio signal RF2 according to the radio communication standard selected for the transmitting device 4. Similar to the radio signals RF1, RF12, RF13, the radio signal RF2 is also broadband, i.e., the bandwidth is greater than approximately 500 MHz, for example, between 1 GHz and 4 GHz. In one embodiment, the radio module generates and transmits a training sequence with the radio signal RF2, which is transmitted periodically or continuously and may be characteristic of the mobile device 6. In the embodiments of the technology described here, the radio module of the mobile device 6 is activated when the user 2 is in the public zone 22.In the activated state, the mobile device 6 transmits the radio signal RF2 continuously, for example; in one embodiment, it can be configured (programmed) such that it transmits the radio signal RF2 only after receiving the radio signal RF1 transmitted by the transmitting device 4, for example as a response signal for synchronization purposes.

[0038] In one embodiment, the mobile device 6 can also be configured to transmit an identifier that allows the mobile device 6 to be assigned to the user 2 (as explained elsewhere in this description). The identifier can be transmitted with the radio signal RF2, for example, embedded therein and in accordance with the radio communication standard used for the radio signal RF2. The identifier can also be transmitted separately from the radio signal RF2, for example, using Bluetooth radio technology or a (possibly narrowband) WLAN / WiFi radio technology; in this case, the selected radio technology is also implemented in the receiving device 14 so that the identifier can be received.

[0039] The mobile device 6 can, for example, have an application-specific software application (also referred to as an app), which can be activated, for example, by the user 2. In one embodiment, the application-specific software application is used in connection with access control and the use of elevators. In one embodiment, the application-specific software controls the generation and transmission of the radio signal RF2. Depending on the configuration, this software can also generate the identifier of the mobile device 6, for example, an identifier that is unique to the mobile device 6 and does not change over time. Such a software-generated identifier represents an alternative to a device identification number and a telephone number, which can also be used as an identifier.

[0040] The determination of the degrees of similarity and their application for positioning are described below in connection with Fig. 3A-Fig. 3F The explanation is given for the transmitting device 4 and the user 2 in order to determine the distance d 1 of the user 2 or the mobile device 6 from the transmitting device 4. The distances d 12 , d 13 to the transmitting devices 4.2, 4.3 can be determined in an analogous manner.

[0041] Fig. 3A shows a schematic representation of multipath signal propagation from radio signal sources (4, 6). The radio signal sources correspond in the situation according to Fig. 1 the transmitting device 4 and the mobile device 6, which are separated from each other by the distance d 1. Fig. 3A also shows the Fig. 1 shown receiving device 14, a wall 3 with two perpendicular wall surfaces and an XY coordinate system.

[0042] The receiving device 12 receives the radio signals RF1, RF2 transmitted by the mobile device 6 and the transmitting device 4. The radio signals RF1, RF2 propagate in all directions in the room and are more or less reflected, diffracted, and / or scattered by any obstacles and walls 3 present, or are otherwise influenced in their propagation. This is known to those skilled in the art, for example, under the term "multipath propagation." For illustration, Fig. 3A Some of these signal paths are shown, with solid lines representing the signal paths of the radio signal RF1 transmitted by the transmitting device 4 and dashed lines representing the signal paths of the radio signal RF2 transmitted by the mobile device 6. The receiving device 14 receives, for example, the radio signal RF2 of the mobile device 6 via a direct path and via a variety of other paths. In an analogous manner, the receiving device 14 receives the radio signal RF1 of the transmitting device 4. The person skilled in the art will recognize that reception via a direct path is not always possible because, for example, there is an obstacle (e.g., a user 2) between the receiving device 14 and the transmitting device 4, and that in such a case the receiving device 14 only receives signals that propagate via indirect paths.

[0043] As explained above, the radio signals RF1, RF2 received by the receiving device 14 are distinguishable, in one embodiment, for example, due to different training sequences. If the training sequence is an m-sequence, then for certain lengths (2 N < -1) of the bit sequences, orthogonal m-sequences exist, by means of which multiple transmitters (here, the transmitting device 4 and the mobile device 6) can send a training sequence to a receiver (here, the receiving device 14) without causing interference. The radio signal RF2 of the mobile device 6 can also transmit the identifier of the mobile device 6, so that it can be distinguished from the radio signal RF1, even if the radio signal RF1 itself does not contain an individual identifier. The receiving device 14 determines an associated channel impulse response h 1 (τ), h 2 (τ) for each radio signal RF1, RF2.

[0044] Those skilled in the art know that the channel impulse response h(τ) is a description of the current linear transmission channel and, by definition, corresponds to the signal that can be determined at an output of the transmission channel when a Dirac pulse is supplied as an input signal at an input of the transmission channel. The channel impulse response describes the effect that the transmission channel has on the input signal, for example, as a function of time. Knowledge of the channel impulse response h(τ) improves, for example, the decoding of received symbols in a receiver; in some radio-based communication systems (e.g. WLAN 802.11), the channel impulse response h(τ) is therefore estimated at the receiver end. The estimation of the channel impulse response h(τ) can be based on a received training sequence.

[0045] Based on the radio signal RF1 transmitted by the transmitting device 4, a first channel impulse response h 1 (τ) can be determined after reception by the receiving device 14; Fig. 3B shows a schematic representation of an exemplary magnitude function | h 1 (τ) | of the first channel impulse response h 1 (τ) as a function of time in nanoseconds (ns). In this exemplary representation, the magnitude function | h 1 (τ) | has four peak values ​​at τ 1 ≈ 26 ns, τ 2 ≈ 40 ns, τ 3 ≈ 47 ns and τ 4 ≈ 55 ns; each of these peak values ​​corresponds to a multipath signal component SC(RF1) k (k = 1, 2, 3, 4) of the radio signal RF1, which are taken into account in the evaluation in this exemplary embodiment.

[0046] Based on the radio signal RF2 transmitted by the mobile device 6, a second channel impulse response h 2 (τ) can be determined after reception by the receiving device 14; Fig. 3C shows a schematic representation of an exemplary magnitude function | h 2 (τ) | of the second channel impulse response h 2 (τ) as a function of time in nanoseconds (ns). In this exemplary representation, the magnitude function | h 2 (τ) | has four peak values ​​at τ 1 ≈ 25 ns, τ 2 ≈ 43 ns, τ 3 ≈ 45 ns and τ 4 ≈ 58 ns; each of these peak values ​​corresponds to a multipath signal component SC(RF2) k (k = 1, 2, 3, 4) of the radio signal RF2, which are taken into account in the evaluation in this exemplary embodiment.

[0047] In one embodiment, the multipath signal components SC(RF1) 1 , SC(RF2) 1 can each correspond to a signal component received via a direct radio path. The receiving device 14 thus has a line of sight to the transmitting device 4 and the mobile device 6. Those skilled in the art will recognize that, depending on the currently prevailing situation in the public zone 22 (e.g., there is an obstacle (e.g., another user or a part of a building) between the mobile device 6 and the receiving device 14), this line of sight may not exist. In such a situation, at least one of these (first) multipath signal components SC(RF1) 1 , SC(RF2) 1 may not occur. The technology described here also makes it possible to determine the degree of similarity in this situation.

[0048] A person skilled in the art will also recognize that the receiving device 14 and the signal processing device 8 are designed, e.g. have a fixed reception bandwidth, to resolve a plurality of multipath signal components SC(RF1) k , SC(RF2) k in the radio signals RF1, RF2 so that they can be evaluated. As explained above, the respective bandwidth of the radio signals RF1, RF2 is greater than 500 MHz; the reception width of the receiving device 14 must be set accordingly. The higher the bandwidth of the radio signals RF1, RF2, the greater the distance between the signal components SC(RF1) k , SC(RF2) k and the more accurately the signal components SC(RF1) k , SC(RF2) k and their time difference can be evaluated. A person skilled in the art will also recognize that the number k of multipath signal components SC(RF1) k , SC(RF2) k is not limited to four.

[0049] The signal processing device 8 detects for each of the channel impulse responses h 1 (τ), h 2 (τ) the multipath signal components SC(RF1) k , SC(RF2) k , the corresponding peak values ​​and their temporal occurrence (τ). This is shown in Fig. 3D und Fig. 3E illustrated. Fig. 3D is a schematic representation of the magnitude function | h 1 (τ) | of the first channel impulse response h 1 (τ) with the four exemplary multipath signal components SC(RF1) k shown, and Fig. 3E is a schematic representation of the magnitude function | h 2 (τ) | of the second channel impulse response h 2 (τ) with the four exemplary multipath signal components SC(RF2) shown, each at the times τ 1 , τ 2 , τ 3 , τ 4 .

[0050] The temporal occurrence of the multipath signal components SC(RF1) k , SC(RF2) k is extracted from the channel impulse responses h 1 (τ), h 2 (τ). For such an extraction process, one embodiment can use the SAGE (Space-Alternating Generalized Expectation-Maximization) algorithm, as described, for example, in: B.H. Fleury, et al., "Channel parameter estimation in mobile radio environments using the SAGE algorithm," IEEE Journal on selected areas in communications, Vol. 17, No. 3, pages 434–450, 1999, and T. Santos, J. Karedal, P. Almers, F. Tufvesson, and A. Molisch, "Modeling the ultra wideband outdoor channel: Measurements and parameter extraction method," IEEE Transactions on Wireless Communications, Vol. 9, No. 1, pages 282–290, 2010.

[0051] Out of Fig. 3B - 3D It can be seen that the channel impulse responses h 1 (τ), h 2 (τ) are similar because the transmitting device 4 and the mobile device 6 are relatively close to each other in the same environment (public zone 22). The smaller the distance d 1 , i.e. the closer the mobile device 6 is to the transmitting device 4, the more similar the channel impulse responses h 1 (τ), h 2 (τ) are. In the opposite case, i.e. with increasing distance d 1 , the similarity of the channel impulse responses h 1 (τ), h 2 (τ) decreases increasingly. In the Fig. 1 In the situation shown, the environment in which the transmitting device 4 and the mobile device 6 are located is relatively narrowly confined; for example, it is an entrance hall in a building. The similarity of the channel impulse responses h 1 (τ), h 2 (τ) is demonstrated, for example, by the fact that (with line of sight) both have four clearly prominent multipath signal components SC(RF1) k , SC(RF2) k , which occur at similar times τ 1 , τ 2 , τ 3 , τ 4 .

[0052] The first-occurring multipath signal component SC(RF1) 1 , SC(RF2) 1 (k = 1) results from the radio signal RF1, RF2, which is received by the receiving device 14 in a direct line-of-sight relationship (e.g., without reflection from the wall 3). The peak values ​​of these first-occurring multipath signal components SC(RF1) 1 , SC(RF2) 1 (k = 1) are generally the largest. The peak values ​​of the subsequent multipath signal components SC(RF1) k , SC(RF2) k (k = 2, 3, 4) generally decrease in sequence.

[0053] According to the technology described here, the similarity of the channel impulse responses h 1 (τ), h 2 (τ) is used to determine a degree of similarity. The distance d 1 is determined based on the degree of similarity. To determine the degree of similarity, the multipath signal components SC(RF1) k , SC(RF2) k (k = 1, 2, 3, 4) are considered in pairs, i.e. the first occurring multipath signal components SC(RF1) 1 , SC(RF2) 1 (k = 1) form a pair P1, and the second occurring multipath signal components SC(RF1) 2 , SC(RF2) 2 (k = 2) form a pair P2; correspondingly, the pairs P3 and P4 are obtained.

[0054] Fig. 3F shows a schematic representation of a graphic overlay of the Fig. 3D und 3E shown magnitude functions | h 1 (τ) | , | h 2 (τ) | , where only the multipath signal components SC(RF1) k , SC(RF2) k are shown. The pairwise consideration of the multipath signal components SC(RF1) k , SC(RF2) k is in Fig. 3F also illustrated. For each of the pairs P1-P4, a time difference Δ k is plotted, which indicates whether the respective multipath signal component SC(RF2) k of the second radio signal RF2 is received by the receiving device 14 before or after the corresponding multipath signal component SC(RF1) k of the first radio signal RF1. A sign of the time difference Δ k indicates which signal component of a pair P1-P4 is received first.

[0055] The Fig. 3F The time differences Δ k shown for each pair P1 - P4 result from the equation Δ k = τ RF 2 k − τ RF 1 k with k = 1, ..., K. Once these time differences Δ k are determined, the pair is identified for which the time difference Δ k has the largest value, ie max { | Δ 1 | , ..., | Δ k |}. The maximum of the value across all pairs is a measure of the similarity of the two channel impulse responses h 1 (τ), h 2 (τ); this measure is called the degree of similarity. For geometric reasons, the distance d 1 is limited, ie d 1 ≥ c ⋅ Δ k for each k. The distance d 1 is determined using the equation d 1 = E S ⋅ c ⋅ SD S , where: c is the speed of light, ES = (K + 1) / K is a correction factor explained below and SD S = max { | Δ 1 | , ..., | Δ k |} is a degree of similarity with a common time reference.

[0056] In the previous explanations for determining the distance d 1 , it is assumed that the radio signals RF1, RF2 have a common time reference, i.e., they are synchronized with each other. This can be achieved, for example, by using highly accurate clocks in the transmitting device 4, the mobile device 6, and the receiving device 14 and / or by means of so-called round-trip time protocols for synchronizing wirelessly connected system components. An overview of such synchronization methods is provided, for example, by Ill-Keun Rhee, et al., "Clock Synchronization in Wireless Sensor Network: An Overview," Sensors 2009, Vol. 9, pp. 56–85.

[0057] For a very high number K of multipath signal components SC(RF1) k , SC(RF2) k for synchronous radio signals RF1, RF2 the correction factor ES approaches 1. With ES = 1 the distance d 1 results from d 1 = c · max { | Δ 1 | , ..., | Δ K |}. For a relatively small number K of multipath signal components SC(RF1) k , SC(RF2) k the correction factor ES = (K + 1) / K. In the embodiment described here with K = 4 ES = 5 / 4.

[0058] The technology described here can also be used if the radio signals RF1 and RF2 do not have a common time reference, ie they are asynchronous to each other. In this case, the distance d 1 is calculated according to d 1 = E A ⋅ c / 2 ⋅ SD A , where: c is the speed of light, EA = (K + 1) / (K - 1) is a correction factor described below and SD A = (max{Δ 1 , ..., Δ K} - min{Δ 1 , ..., Δ K}) is a degree of similarity in the absence of a common time reference.

[0059] Even with asynchronous radio signals RF1, RF2, the correction factor EA approaches 1 for a very high number K of multipath signal components SC(RF1) k , SC(RF2) k . With EA = 1, the distance d 1 is given by d 1 = c / 2 · (max {Δ 1 , ..., Δ K} - min{Δ 1 , ..., Δ K}). With a relatively small number K of multipath signal components SC(RF1) k , SC(RF2) k , the correction factor EA = (K + 1) / (K - 1). In the embodiment described here with K = 4, EA = 5 / 3.

[0060] The distance d 1 is determined using the procedure described above; it indicates how far the user 2 or the mobile device 6 is from the transmitting device 4. Analogously to this procedure, the distances d 12 , d 13 can be determined. To determine the distances d 12 , d 13 , degrees of similarity are also determined. The degree of similarity between the transmitting device 4.2 and the mobile device 6 is determined from an evaluation of a channel impulse response h 12 (τ), which is based on the radio signal RF12 (transmitting device 4.2), and the channel impulse response h 2 (τ). From this, the distance d 12 between the transmitting device 4.2 and the mobile device 6 can be determined. From an evaluation of a channel impulse response h 13 (τ), which is based on the radio signal RF13 (transmitting device 4.3), and the channel impulse response h 2 (τ), the degree of similarity with regard to the transmitting device 4.3 and the mobile device 6 is determined. From this, the distance d 13 between the transmitting device 4.3 and the mobile device 6.

[0061] The distances d 1 , d 12 , d 13 are determined essentially simultaneously by the signal processing device 8. At a specific point in time, the three distances d 1 , d 12 , d 13 are therefore available in relation to the user 2. Using a trilateration method, the position of the user 2 in the building can be determined from this. Trilateration is a measuring method for determining the position of a point, which is based on distance measurements to three points. If, for example, only the distance to a known point is known, then when viewed from a plane, the location of an observer lies on a circle around this point. If three points are known, the location is at the intersection points of the circle lines. The more measurements are available for different reference points, the more accurately the position can be determined. For the technology described here, this means that three or more transmitting devices 4, 4.2, 4.3 can be used to determine the position.

[0062] Knowledge of the location of user 2 can be used in different ways within the building. In one embodiment, it can be detected whether user 2 is in the public zone 22 or (authorized or unauthorized) in the restricted access zone 20. In the case of an authorized user 2, for example, an identifier sent by the mobile device 6 can be used to determine whether user 2 is known. If user 2 is known, a user profile is created for them in a building management system, for example, wherein the user profile specifies which rights user 2 has within the building. This can be used, for example, to decide whether and which building action (e.g., a security measure) should be initiated.

[0063] In one embodiment, the position determination is carried out continuously. For example, once a position determination is complete, a new position determination is carried out after a specified period of time. The period of time can, for example, be in the range of seconds or milliseconds. Thus, not only is a current position determined, but a change in the position is also detected. If the user 2 walks around the public zone 22, for example, different positions result in successive time. This allows the path of the user 2 to be tracked. Depending on the design of the building system 1, the positions and the path can be saved and / or displayed graphically in a building plan.

[0064] Using the specified time period, it is also possible to determine the speed (V = distance / time) at which user 2 is moving along the path. From the path, it is also possible to determine the direction in which user 2 is going. If, for example, they are moving towards a destination (e.g., elevator or airlock), it is possible to determine when they are likely to arrive there. If this information is available, a building action can be initiated before the user reaches the destination (possibly taking into account the rights defined in the user profile). The building action can, for example, include providing an elevator car, unlocking a door, or initiating a security measure (e.g., if an unauthorized user 2 is moving towards the airlock).

[0065] In the public zone 22, several users 2 can be present, as in Fig. 2 shown, with each user 2 carrying a mobile device 6. If this is the case, the position of each present user 2 is determined according to the procedure described above. In one embodiment, the mobile devices 6 are differentiated according to the training sequences or identifiers mentioned above. The technology described here can thus be applied separately for each present and distinguishable user 2 in order to determine the position or position changes of this user 2. If the positions of the present users 2 are known, the distances between the users can be determined from this.

[0066] The position of user 2 or the positions of users 2 determined in this way can be used in different ways. In buildings and situations that, for example, Fig. 1 und Fig. 2 Exceptional situations may occur if the situations shown are similar to those shown. A possibly unauthorized user may follow an authorized user 2, who is allowed to enter the restricted-access zone 20, so closely that this user may, in a sense, freeloader and possibly enter the restricted-access zone 20 undetected. Fig. 1 At the turnstile (16) shown, which is used to separate users, the unauthorized user may be able to push past the authorized user. Another exceptional situation may arise if users belonging to a group wish to access zone 20. The users of this group can, for example, be channeled together through access 24 to keep delays to a minimum. The technology described here can also be used advantageously for these exceptional situations.

[0067] The technology described here detects, for example, a free rider or tailgating situation in which, for example, an unauthorized user follows an authorized user 2. The technology determines by means of the Fig. 3F The procedure described above records the positions of these users and the temporal progression of these positions. From this, the distance between the unauthorized user and authorized user 2 can be determined. If the distance is less than a specified distance (individual users who do not know each other, for example, typically keep their distance from each other), this indicates a pushy situation. In this case, building system 1 can, for example, initiate a security measure. The security measure can include triggering an alarm and / or alerting security personnel to assess whether the situation actually is a pushy situation.

[0068] The technology described here also detects when several users are standing relatively close together and form a group. This detection is based on a distance limit set for groups being reached or undercut, e.g. because the users know each other and are therefore standing closer together. This group may, for example, be located away from other users who may be present. Similar to the free rider or pushy person situation described, the detection of a group situation is based on the determination of inter-user distances, i.e. the distances that exist between the users. Since the position of each user present is determined, a multitude of inter-user distance values ​​can be determined. From the evaluation of these distance values, it can be determined whether and which users are close to one another. These users are assigned to the group.In this situation, Building System 1 can also initiate a security measure, for example, requesting security personnel to escort the users through together as a group.

[0069] As mentioned above, the building system 1 can comprise an elevator system, an access control system, or a combination of such systems. Depending on the position of a user 2 and based on information about the access authorization of the user 2, e.g., based on the identifier assigned to them, the access control system controls the access 24 so that only authorized users 2 can enter the zone 20, for example by blocking or releasing a door, a barrier, a turnstile, or another physical barrier or gate. For access points 24 without such physical barriers, the access control system can, for example, control the access 24 by triggering a visual and / or acoustic alarm upon detection of an unauthorized user; alternatively or additionally, notification of a security service can be initiated.Regardless of whether the lock is equipped with or without a physical barrier, any existing information device can also be activated, for example, to inform a user. Fig. 1 und Fig. 2 Two turnstiles 16 are shown as exemplary physical barriers, which the controller (ACS) 11 of the access control system controls via a wired and / or wireless connection 26.

[0070] In Fig. 1 und Fig. 2 For illustrative purposes, components of the access control system are arranged in the access 24 or in its surroundings. Depending on the traffic volume for which the access control system is intended, the access 24 consists of several individual gates; for example, each of the two turnstiles 16 can represent a gate. Those skilled in the art will recognize that in a specific implementation, the access control system or its components can be arranged differently than shown in the figures. Each individual gate can, for example, represent a single access at which a transmitting device 4 can be arranged.

[0071] The Fig. 1 The rooms 18 shown can, for example, belong to a group of elevators, which comprises, for example, four elevators (AD) and is controlled by an elevator control system (ECS) 10. If a user 2 moves towards the entrance 24, this means in one embodiment that the user 2 wishes to be transported with one of the elevators to a destination floor specified for this user 2. According to one embodiment, such transport represents a building action desired by the user 2. Upon recognition of the user 2, a destination call is initiated, to whom the elevator control system 10 assigns an elevator (AD) for a journey from a boarding floor to a destination floor. The assigned elevator (AD) is communicated to the user 2, for example by means of a display unit. In the Fig. 1 und Fig. 2 In the situations shown, a display unit can be assigned to each turnstile 16. For example, if user 2 uses one of the turnstiles 16 shown, the access control system detects which turnstile 16 user 2 is at and controls the display unit located there to display the assigned elevator (e.g., "A"). Those skilled in the art will recognize that the assigned elevator can be communicated to user 2 visibly and / or audibly.

[0072] With the understanding of the principal system components and their functionalities described above, the following in connection with Fig. 4 and Fig. 5 a description of an exemplary method for operating the building system based on the Fig. 1 shown situation (i.e. a single user 2). Fig. 4 shows a simplified flowchart of the procedure, while Fig. 5 shows a flowchart with more detailed steps of the procedure.

[0073] The description is based on user 2, who is located in public zone 22 and may wish to enter restricted zone 20 at entrance 24, for example, to use an elevator. User 2 carries mobile device 6 and has activated its radio module (e.g., for broadband WLAN / WiFi or UWB communication). Any associated software application is activated. The stationary transmitting devices 4, 4.2, 4.3 are also activated and transmit the (primary) radio signals RF1, RF2, RF3.

[0074] The Fig. 4 The procedure shown begins in one step S1 and ends in one step S7. The person skilled in the art will recognize that the division into these steps is exemplary, that one or more of these steps can be divided into one or more sub-steps and that several of the steps can be combined into one step.

[0075] In one step S2 The receiving device 14 receives the radio signals RF1, RF2, RF3 transmitted by the transmitting devices 4, 4.2, 4.3, wherein each radio signal RF1, RF2, RF3 transmits a training sequence associated with the respective transmitting device 4, 4.2, 4.3. The signal processing device 8 determines for each of these received radio signals RF1, RF2, RF3 and, based thereon, a channel impulse response h 1 (τ), h 12 (τ), h 13 (τ), as described in connection with Fig. 3B For better differentiation, these channel impulse responses h 1 (τ), h 12 (τ), h 13 (τ) are also referred to as primary channel impulse responses h 1 (τ), h 12 (τ), h 13 (τ).

[0076] If the user 2 is located with his mobile device 6 in the public zone 22 and within radio range of the receiving device 14, the receiving device 14 receives in one step S3a (secondary) radio signal RF2 transmitted by the mobile device 6, which transmits the training sequence assigned to the mobile device 6. The signal processing device 8 determines a secondary channel impulse response h 2 (τ) based on the received radio signal RF2, as in connection with Fig. 3C is explained.

[0077] The mobile device 6 transmits the radio signal RF2, for example, in response to received radio signals that the transmitting devices 4, 4.2, 4.3 transmit, for example, periodically. These radio signals can be the radio signals RF1, RF2, RF3 or one or more separate radio signals for synchronization purposes. The radio signal RF2 contains a training sequence, as described above, by which the radio signal RF2 can be distinguished from the radio signals RF1, RF2, RF3 in the evaluation device 12. The mobile device 6 can also transmit the radio signal RF2 independently of an external event or influence (e.g., without receiving one or more radio signals), for example, controlled by the software application.

[0078] The mobile device 6 can also transmit an identifier of the mobile device 6, either embedded in the radio signal RF2 or as a separate radio signal, which is transmitted, for example, using Bluetooth technology. Using this identifier, it can be checked whether it is assigned to an authorized user 2 in a database containing a plurality of user profiles. The controller 11 of the access control system can, for example, perform this check immediately after the (first) receipt of the identifier by the receiving device 14, even if the user 2 is only in the public zone 22 and does not yet wish to access the system. The check can also only be carried out when the user 2 actually wishes to access the system, for example, when they are very close to the access 24 or the transmitting device 14. In the exemplary embodiment described here, it is assumed that the user 2 is authorized to access the system and, in one step S6a desired building action is initiated.

[0079] In one step S4 The signal processing device 8 determines the degree of similarity of the channel impulse responses h 1 (τ), h 12 (τ), h 13 (τ), h 2 (τ) by comparing the secondary channel impulse response h 2 (τ) with each of the primary channel impulse responses h 1 (τ), h 12 (τ), h 13 (τ). The degree of similarity (max { | Δ 1 | , ..., | Δ K |}) is determined according to the above equation Δ K = τ RF2< k - τ RF1< k.

[0080] In one step S5 The distances d 1 , d 12 , d 12 are determined based on the degrees of similarity. For synchronous radio signals RF1, RF12, RF13, RF2, the distance is determined for each transmitting device 4, 4.2, 4.3 according to d = ES · c . max { | Δ 1 | , ..., | Δ K |}; for asynchronous radio signals RF1, RF12, RF13, RF2, the distance is determined according to d = EA · c / 2 · (max {Δ 1 , ..., Δ K} - min{Δ 1 , ..., Δ K}).

[0081] In one step S6 The position of the mobile device 6 is determined. In one embodiment, the position of the user 2 or the mobile device 6 is determined from the distances d 1 , d 12 , d 12 by means of trilateration. As mentioned above, the position determination can be carried out continuously, for example, to track the path of the user 2.

[0082] As mentioned above, Fig. 5 a flowchart with more detailed steps of the method according to an embodiment. In Fig. 5 is the one in Fig. 4 shown step S4 more detailed through steps S4.1, S4.2 shown the steps S1-S3 and S5-S7 essentially correspond to the Fig. 4 steps shown.

[0083] In step S4.1For the (secondary) channel impulse response h 2 (τ), the multipath signal components SC(RF2) k are determined, and for each primary channel impulse response h 1 (τ), h 12 (τ), h 13 (τ), multipath signal components are also determined, as in connection with Fig. 3D und Fig. 3E (related to the transmitting device 4). In the embodiment described here, four multipath signal components (K = 4) are determined.

[0084] In one step S4.2 For each primary channel impulse response h 1 (τ), h 12 (τ), h 13 (τ), a pairwise comparison of its multipath signal components with the multipath signal components SC(RF2) k of the secondary channel impulse responses h 2 (τ) is carried out. From this comparison, the temporal deviation Δ k = τ RF2< k - τ RF1< k is determined for each pair P1 - P4, as in conjunction with Fig. 3F is explained.

[0085] Deviating from the Fig. 1 shown situation, may change according to the Fig. 2 In the situation shown, several users 2 (U 1 , U 2 , U 3 , U 4 ) are in the public zone 22. Each of these users 2 carries a mobile device 6 which, as described above, transmits a radio signal according to the radio technology used in the building. The receiving device 14 therefore receives a plurality of further radio signals. For each of the radio signals, a further channel impulse response is determined, which is compared with the first channel impulse response h 1 (τ) in order to determine a distance d 1 , d 2 , d 3 , d 4 of the respective electrical device 6 to the transmitting device 4. Distances to the further transmitting devices 4, 4.2, 4.3 can be determined analogously to the above explanations. This makes it possible, for example, to identify which user 2 (U 1 , U 2 , U 3 , U 4 ) is closest to the transmitting device 4.

[0086] As mentioned above, in one embodiment, in addition to the receiving device 14, the receiving device 14A is present and connected to the signal processing device 8, as shown in Fig. 2 shown. The receiving device 14A is arranged to receive the radio signals RF1, RF12, RF13 from the transmitting devices 4, 4.2, 4.3. If the mobile device 6 is within reception range of the receiving device 14A, the latter also receives the radio signal RF2 transmitted by the mobile device 6.

[0087] The signal processing device 8 thus processes channel impulse responses based on the reception of the radio signals RF1, RF12, RF13, RF2 by the receiving device 14A. The processing includes the Fig. 3F described pairwise determination of time differences Δ k according to Δ k = τ RF2< k - τ RF1< k . The signal processing device 8 also processes the channel impulse responses which are based on the reception of the radio signals RF1, RF12, RF13, RF2 by the receiving device 14 in order to determine time differences Δ k. From the totality of these time differences Δ k , ie based on the reception by the receiving devices 14, 14A, the pair is determined for which the time difference Δ k has the greatest value, ie max { | Δ 1 | , ..., | Δ κ |}. The further processing in order to determine the distance is carried out as described above. An advantage of using the additional receiving device 14 is that it improves the accuracy of the distance determination.

[0088] Fig. 6 is a schematic representation of an embodiment of the signal processing device 8 of the Fig. 1 und Fig. 2shown access control system 1. The signal processing device 8 comprises a processor unit 30, a memory device 34, and an interface device 32 with a signal input 40 and a signal output 42. The memory device 34 is designed to store a measurement database 38 and a computer program 36. The processor unit 30 is communicatively connected to the memory device 34 in order to access the measurement database 38 and the computer program 36 according to the technology described here. The processor unit 30 is also communicatively connected to the interface device 32 in order to receive signals from the receiving device 14, 14A via a signal input 40 of the interface device 32 and to send signals to the controller 11 of the access control system 1 via a signal output 42 of the interface device 32.

[0089] The identifier of the mobile device 6 of an authorized user 2, mentioned in the preceding exemplary embodiments, or the identifiers of other authorized users, can be stored in a memory device of the access control system 1 in one exemplary embodiment. Those skilled in the art will recognize that the number of users 2 present in the public zone 22 varies over time and that the memory device is updated when a mobile device 6 is no longer within radio range, e.g., because the associated user 2 has left the public zone 22 without requesting access to the restricted-access zone 20 or because the associated user 2 has already entered the restricted-access zone 20. The memory device thus stores data records for users 2 who are present in the public zone 22 at a specific time.The access control system therefore "knows" how many mobile devices 6 are within radio range at a given time and, if their users 2 are registered users 2 for the building, to which users 2 the mobile devices 6 belong. At this time, the access control system can check for each registered user 2 which rights are defined for user 2 in the building.

[0090] For each registered user 2, a user profile is created in the access control system, i.e., it is stored as a data record in a database. The user profile includes personal data of user 2 (e.g., name, reason for authorization (resident, employee, external service provider, visitor)), access authorizations (e.g., specific rooms 18 and floors), and any time-based access restrictions (e.g., access from Monday to Friday, from 7:00 a.m. to 8:00 p.m.). The user profile also assigns at least one mobile device 6 to user 2. As an alternative to creating the user profile in the access control system, the user profile can be created in a database of a building management system, whereby the access control system can access this database via a communications network.

[0091] The mobile device 6 can be, for example, a mobile phone, a smartphone, a tablet PC, or a smartwatch, whereby these devices are typically equipped with hardware that enables wireless communication. The mobile device 6 can also be glasses with a miniature computer or another computer-based device worn on the body (also referred to as a "wearable device"). Depending on the design of the mobile device 6, it can, for example, have a graphical user interface (GUI) to enable the mobile device 6 and its functions to be selectively activated and deactivated.

Claims

1. Method for operating a building system (1), the building system (1) comprising a control device (10, 11), transmitting devices (4, 4.2, 4.3) for primary radio signals (RF1, RF12, RF13), in particular a first transmitting device (4) for a first radio signal (RF1), a second transmitting device (4.2) for a second radio signal (RF12), a third transmitting device (4.3) for a third radio signal (RF13), a receiving device (14) for radio signals and a signal processing device (8) communicatively connected to the receiving device (14), the method comprising: determining, by the signal processing means (8), primary channel impulse responses (h1(τ), h12 (τ), h13 (τ)), wherein a first primary channel impulse response (h1 (τ) is based on the first radio signal (RF1) received by the receiving means (14), wherein a second primary channel impulse response (h12 (τ)) is based on the second radio signal (RF12) by the receiving device (14), and wherein a third primary channel impulse response (h13 (τ)) is based on the third radio signal (RF13) received by the receiving device (14); determining, by the signal processing means (8), a secondary channel impulse response (h2(τ)) based on a secondary radio signal (RF2) received by the receiving means (14), wherein the secondary radio signal (RF2) is transmitted from a first mobile electronic device (6) of a first user (2), determining, by the signal processing means (8), degrees of similarity (SDS, SDA) by evaluating the channel impulse responses (h1(τ), h12 (τ), h13 (τ), h2 (τ)), where a first degree of similarity (SDS, SDA) indicates how similar the first primary channel impulse response (h1 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other, wherein a second degree of similarity (SDS, SDA) indicates how similar the second primary channel impulse response (h12 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other, and wherein a third degree of similarity (SDS, SDA) indicates how similar the third primary channel impulse response (h13 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other; determining, by the signal processing means (8), for each degree of similarity, a distance (d1, d12, d13) of the mobile device (6) to the transmitting device (4, 4.2, 4.3) corresponding to the degree of similarity, which are arranged in the building at predetermined locations; determining, by the signal processing device (8), a position of the mobile device (6) based on the distances (d1, d12, d13); whereby a first sequence of temporally consecutive first multipath signal components (SC(RF1)k) is determined from each of the primary channel impulse responses (h1(τ) h12(τ), h13(τ)); whereby a second sequence of temporally consecutive second multipath signal components (SC(RF2)k) is determined from the secondary channel impulse response (h2(τ)); wherein the evaluation of the primary and secondary channel impulse responses (h1(τ), h12(τ), h13(τ), h2(τ)) comprises a pairwise comparison, according to the order in the first and second sequence, of each second multipath signal component (SC(RF2)k) with its first multipath signal component (SC(RF1)k) corresponding to the order, to determine a temporal deviation (Δk) for each pair (P1, P2, P3, P4) such that a maximum temporal deviation (Δk) and a minimum temporal deviation (Δk) are present, wherein the degree of similarity (SDS, SDA) is based on at least one of these temporal deviations (Δk), wherein the first, second and third radio signals (RF1, RF12, RF13) and the secondary radio signal (RF2) have a common time reference, wherein for each of the degrees of similarity the determination of the distance (d1, d12, d13) according to d = ES − c − SDS where: c is the speed of light, ES = (K + 1) / K is a correction factor and SDS = max { | Δ1 | , ..., | ΔK | } is the degree of similarity with a common time reference, or wherein the first, second and third radio signals (RF1, RF12, RF13) and the secondary radio signal (RF2) do not have a common time reference, wherein for each of the degrees of similarity the determination of the distance (d1, d12, d13) according to d = EA − c / 2 − SDA , where: c the speed of light, EA = (K + 1) / (K - 1) a correction factor, SDA = (max{Δ1, ..., ΔK} - min{Δ1, ..., ΔK}) the degree of similarity with no common time reference, K the number of multipath signal components SC(RF1)k, SC(RF2)k, max{Δ1, ...., ΔK} the maximum temporal deviation from temporal deviations | Δ1 | , ..., | ΔK | and min {Δ1, ..., ΔK}) the minimum temporal deviation from temporal deviations | Δ1 | , ..., | ΔK |.

2. The method according to claim 1, wherein the position of the mobile device (6) is determined by means of a method for trilateration.

3. The method according to any one of the preceding claims, further comprising determining a first identifier of the first mobile electronic device (6) from the second radio signal (RF2), wherein the first identifier is associated with a user profile if the first user (2) is authorized to access.

4. The method according to any one of the preceding claims, wherein the receiving device (14) receives a number of further secondary radio signals emitted by a number of further mobile electronic devices (6), which are assigned to the further users (2), wherein based on each received further secondary radio signal a channel impulse response is determined, which is evaluated in conjunction with the primary channel impulse responses (h1 (τ), h12 (τ), h13 (τ)) to determine distances (d1, d2, d3, d4) of the corresponding further mobile electronic device (6) to the transmitting devices (4, 4.2, 4.3) in order to determine the positions of the other mobile electronic devices (6).

5. The method according to claim 4, further comprising, using the positions of the further mobile electronic devices (6), determining distances between the further users (2).

6. Method according to one of the preceding claims, wherein the radio signals (RF1, RF12, RF13, RF2) have a bandwidth of at least 500 MHz and are transmitted and received according to a WLAN / WiFi standard or a standard for an ultra-wideband technology.

7. System (1) for determining a position of a user (2) in a building, wherein the system (1) comprises: a control device (10, 11) transmitting devices (4, 4.2, 4.3) for primary radio signals (RF1, RF12, RF13), in particular a first transmitting device (4) for a first radio signal (RF1), a second transmitting device (4.2) for a second radio signal (RF12), and a third transmitting device (4.3) for a third radio signal (RF13) a receiving device (14) for radio signals; and a signal processing device (8) which is communicatively connected to the receiving device (14), wherein the signal processing device (8) is designed, - to determine primary channel impulse responses (h1(τ), h12(τ), h13 (τ)), wherein a first primary channel impulse response (h1 (τ)) is based on the first radio signal (RF1) received by the receiving means (14), wherein a second primary channel impulse response (h12 (τ)) is based on the second radio signal (RF12) by the receiving device (14), and wherein a third primary channel impulse response (h13 (τ)) is based on the third radio signal (RF13) received by the receiving device (14); - to determine a secondary channel impulse response (h2 (τ)) based on a secondary radio signal (RF2) received by the receiving device (14), wherein the secondary radio signal (RF2) can be emitted from a first mobile electronic device (6) of a first user (2) - to determine degrees of similarity (SDS, SDA) by evaluating the channel impulse responses (h1 (τ), h12 (τ), h13 (τ), h2 (τ)), wherein a first degree of similarity (SDS, SDA) indicates how similar the first primary channel impulse response (h1 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other, wherein a second degree of similarity (SDS, SDA) indicates how similar the second primary channel impulse response (h12 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other, and a third degree of similarity (SDS, SDA) indicates how similar the third primary channel impulse response (h13 (τ)) and the secondary channel impulse response (h2 (τ)) are to each other; - to determine for each degree of similarity a distance (d1, d12, d13) of the mobile device (6) to the transmitting device (4, 4.2, 4.3) corresponding to the degree of similarity, which are arranged in the building at predetermined locations; and - to determine a position of the mobile device (6) based on the distances (d1, d12, d13); wherein the signal processing means (8) is further configured to determine from each of the primary channel impulse responses (h1(τ) h12(τ), h13(τ)) a first sequence of temporally consecutive first multipath signal components (SC(RF1)k), and to determine from the secondary channel impulse response (h2(τ)) a second sequence of temporally consecutive second multipath signal components (SC(RF2)k); - wherein the evaluation of the primary and secondary channel impulse responses (h1(τ), h12(τ), h13(τ), h2(τ)) comprises a pairwise comparison, according to the order in the first and second sequence, of each second multipath signal component (SC(RF2)k) with its first multipath signal component (SC(RF1)k) corresponding to the order, to determine a temporal deviation (Δk) for each pair (P1, P2, P3, P4) such that a maximum temporal deviation (Δk) and a minimum temporal deviation (Δk) are present, wherein the degree of similarity (SDS, SDA) is based on at least one of these temporal deviations (Δk), - wherein the first, second and third radio signals (RF1, RF12, RF13) and the secondary radio signal (RF2) have a common time reference, wherein for each of the degrees of similarity the determination of the distance (d1, d12, d13) according to d = ES − c − SDS - where: c is the speed of light, ES = (K + 1) / K is a correction factor and SDS = max{ | Δ1 | , ..., | ΔK | } is the degree of similarity with a common time reference; or - wherein the first, second and third radio signals (RF1, RF12, RF13) and the secondary radio signal (RF2) do not have a common time reference, wherein for each of the degrees of similarity the determination of the distance (d1, d12, d13) according to d = EA − c / 2 − SDA , - where: c the speed of light, EA = (K + 1) / (K - 1) a correction factor, SDA = (max{Δ1, ..., ΔK} - min{Δ1, ..., ΔK}) the degree of similarity with no common time reference, K the number of multipath signal components SC(RF1)k, SC(RF2)k, max{Δ1, ...., ΔK} the maximum temporal deviation from temporal deviations | Δ1 | , ..., | ΔK | and min{Δ1, ..., ΔK}) the minimum temporal deviation from temporal deviations | Δ1 |, ..., | ΔK |.

8. System (1) according to claim 7, wherein the signal processing device (8) is designed to determine the position of the mobile device (6) by means of a method for trilateration.

9. System (11) according to one of claims 7 - 8, in which the radio signals (RF1, RF12, RF13, RF2) have a bandwidth of at least 500 MHz and in which the transmitting device (4) and the receiving device (14) are designed according to a WLAN / WiFi standard or a standard for an ultra-wideband technology.