Method, computer program and transceiver module for adjusting time synchronization

Abstract

Embodiments of the present invention relate to a method, computer program, and transceiver module for adjusting time synchronization between a mobile device and one of a plurality of transceiver modules. The method is performed by the transceiver module, and the method includes listening to time synchronization signals of other transceiver modules in at least some of a plurality of time periods. Each of the plurality of time periods is assigned to one of the plurality of transceiver modules. The method also includes adjusting the time synchronization if the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module. The method also includes sending a time synchronization signal for other transceiver modules based on the time synchronization between the mobile device and the transceiver module.

Description

Technical Field

[0001] Embodiments of the present invention relate to a method, a computer program and a transceiver module for adjusting time synchronization between a mobile device and a transceiver module of a plurality of transceiver modules. Background Art

[0002] In the case of periodic positioning of mobile transceivers by a vehicle equipped with multiple transceivers, for example using the protocol proposed in the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard, the energy consumption of the vehicle transceivers is particularly high as long as the mobile transceiver is not within the radio range of the vehicle transceivers.

[0003] In order to determine the position of the mobile transceiver, the method specified in the IEEE 802.15.4 standard for safe distance measurement by exchanging special radio messages with a large spectrum bandwidth can be used (for example, by double-sided two-way ranging (DS-TWR) in IEEE 802.15.4, where "ranging" corresponds to distance measurement). For the method specified in IEEE 802.15.4, the radio message sent by the mobile transceiver can first be received by the transceiver installed in the vehicle. Since the mobile transceiver and the transceiver installed in the vehicle usually have no common knowledge of the time of the transmission time point, the transceiver installed in the vehicle may wait and realize the reception of the radio message at any time.

[0004] After the mobile transceiver device enters the radio range of one of the transceiver devices installed in the vehicle and a radio message from the mobile transceiver device is received by the transceiver device installed in the vehicle, the relevant transceiver device in the vehicle can reduce its energy consumption in the following way, namely, by deactivating the relevant transceiver device in the vehicle until the next periodic positioning and reactivating it only shortly before the time point of the next upcoming positioning.

[0005] Since the transceivers installed in the vehicle are spatially distributed and the entry of a mobile transceiver into the radio range of a specific transceiver installed in the vehicle only results in a reduction in the current consumption of one specific transceiver installed in the vehicle. For the special case in which a plurality of transceivers installed in the vehicle are connected to a common bus system, time synchronization information can be distributed between the transceivers installed in the vehicle so that they can also reduce energy consumption by applying the information to periodic radio processes as described above. A bus protocol suitable for this is standardized in IEEE 1588 and is called the Precision Time Protocol (PTP). In order to be able to distribute the time synchronization information appropriately according to IEEE 1588, the underlying bus system should meet special characteristics that are usually not given in vehicle data bus systems such as LIN (Local Interconnect Network) bus systems and CAN (Controller Area Network) bus systems.

[0006] If the transceiver installed in the vehicle does not have such a connection via the vehicle bus network, energy consumption cannot be reduced throughout the vehicle. Summary of the invention

[0007] For example, in a vehicle, there is a need to provide an improved method for reducing the energy consumption of a transceiver module group.

[0008] Some embodiments of the present disclosure take this need into account. Some embodiments of the present disclosure are based on the following recognition: the technology for time synchronization between a mobile device (mobile transceiver device) and a transceiver module (such as a transceiver device of a vehicle) can be adjusted to be used to transfer time synchronization between transceiver modules. Therefore, for example, one of the transceiver modules can have high-precision time synchronization with the mobile device and provide a time synchronization signal based on this for other transceiver modules, and then the other transceiver modules can use the time synchronization signal to adjust their own time synchronization and subsequently have improved time synchronization with the mobile device. For this purpose, a time period or time slot set in addition to the time period provided for ranging between the mobile device and the transceiver module can be used in the communication of the corresponding transceiver module. For example, time synchronization may deteriorate over time through time drift between the quartz-based oscillators used in the mobile device and the transceiver module. In addition, time synchronization methods with different characteristics and different precision may be used sequentially in time, and the order depends on the situation and is not known in advance. Therefore, in the time synchronization between the mobile device and the transceiver module and between the transceiver modules, if the received time synchronization signal is more accurate than the time synchronization used before, the time synchronization can be adjusted. Due to the improved time synchronization, the receiving characteristics of the transceiver modules can now be adjusted so that the corresponding transceiver module must be ready to receive in a shorter time. This enables the energy consumption of all transceivers installed in the vehicle to be reduced by extending the radio protocol provided for the positioning of mobile transceivers by distributing the required information.

[0009] Some embodiments of the present disclosure provide a method for adjusting time synchronization between a mobile device and one of a plurality of transceiver modules. The method is performed by the transceiver module. The method includes listening to time synchronization signals of other transceiver modules in the plurality of transceiver modules in at least some of a plurality of time periods. Each of the plurality of time periods is assigned to a transceiver module in the plurality of transceiver modules. The method also includes adjusting time synchronization if the received time synchronization signal has an estimated accuracy higher than that of the time synchronization between the mobile device and the transceiver module. The method also includes sending a time synchronization signal to the other transceiver modules based on the time synchronization between the mobile device and the transceiver module. By receiving and sending the time synchronization signal, time synchronization can be exchanged at least between the transceiver modules. Here, if the received time synchronization signal is more accurate than the time synchronization previously used, the local time synchronization can be adjusted. As previously described, this can reduce the energy consumption of the transceiver of the transceiver module.

[0010] In some embodiments, the received and transmitted time synchronization signals may include information about the estimated accuracy of the corresponding time synchronization signal. Thus, the corresponding receiving transceiver module may estimate whether the received time synchronization signal is more accurate than the time synchronization currently used in the corresponding transceiver module.

[0011] For example, the method may include adjusting the estimated accuracy of the time synchronization based on the time span since the last adjustment of the time synchronization, based on the estimated accuracy of the time synchronization signal based on which the time synchronization was last adjusted, and based on the accuracy of the timer of the transceiver module. Thus, degradation of the time synchronization caused by time drift between quartz oscillators can be taken into account.

[0012] In some embodiments, the method further comprises listening for a time synchronization signal of the mobile device within a predefined period.Thus, time synchronization with the mobile device can be adjusted directly based on the signal of the mobile device and then communicated to other transceiver modules accordingly.

[0013] For example, if the accuracy of the time synchronization is below a threshold, the time synchronization signal can be intercepted. In other words, the adjustment of the time synchronization can only be performed when the quality of the time synchronization is no longer high enough, thereby saving energy during this period.

[0014] The method may further include adjusting a signal receiving time period of a transceiver of the transceiver module based on the adjusted time synchronization. By adjusting the signal receiving time period, for example, the time period may be shortened, thereby saving energy.

[0015] For example, the signal receiving time period of the transceiver for receiving the positioning signal from the mobile device can be adjusted based on the adjusted time synchronization, thereby avoiding the corresponding transceiver from having to remain activated for a longer period of time for ranging.

[0016] For example, the time synchronization signal of the other transceiver module is based on ultra-wideband transmission technology (UWB). In other words, time synchronization can be transmitted between transceiver modules by means of UWB. The time synchronization signal of the mobile device can be based on ultra-wideband transmission technology or Bluetooth transmission technology (such as low-energy Bluetooth (BLE or Bluetooth LE)). In other words, the initial time synchronization between the mobile device and the transceiver module can be based on UWB or Bluetooth LE.

[0017] In different embodiments, the plurality of transceiver modules may be disposed at different locations of the vehicle. For example, the transceiver module may be used to determine the location of the mobile device relative to the vehicle. The embodiment also provides a vehicle having the transceiver module or the plurality of transceiver modules.

[0018] The embodiments of the present disclosure also provide a program having a program code, which is used to execute the method when the program code is executed on a computer, a processor, a control module or a programmable hardware component.

[0019] Embodiments of the present disclosure also provide a transceiver module having one or more processors and one or more transceivers. The transceiver module is configured to adjust the time synchronization between a mobile device and the transceiver module by listening to the time synchronization signals of other transceiver modules in the multiple transceiver modules in at least some of the multiple time periods via the transceiver. Each of the multiple time periods is assigned to a transceiver module in the multiple transceiver modules. The multiple transceiver modules include the transceiver module. The transceiver module is also configured to adjust the time synchronization if the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module. The transceiver module is also configured to send a time synchronization signal to other transceiver modules through the transceiver based on the time synchronization between the mobile device and the transceiver module. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Some examples of the device and / or method are described in detail below with reference to the accompanying drawings only for exemplary purposes. The accompanying drawings are as follows:

[0021] Figure 1a A flow chart illustrating an embodiment of a method for adjusting time synchronization;

[0022] Figure 1b A block diagram illustrating one embodiment of a transceiver module for adjusting time synchronization;

[0023] Figure 2 A timing diagram showing time synchronization between a mobile device and a transceiver module;

[0024] Figure 3 A timing diagram showing time synchronization between a mobile device and a transceiver module and between different transceiver modules;

[0025] Figure 4 An example packet format is shown;

[0026] Figure 5a An exemplary network diagram illustrating a network having a mobile device and a plurality of transceiver modules;

[0027] Figure 5b An exemplary timing diagram illustrating time synchronization between a mobile device and a transceiver module and between different transceiver modules, wherein initial time synchronization is performed via Bluetooth Low Energy;

[0028] Figure 6a An exemplary network diagram illustrating a network having a mobile device and a plurality of transceiver modules;

[0029] Figure 6b Exemplary timing diagrams showing time synchronization between a mobile device and one transceiver module and between different transceiver modules, with additional time synchronization being performed via UWB. DETAILED DESCRIPTION

[0030] Various examples will now be described in more detail with reference to the accompanying drawings, in which some examples are shown. In the accompanying drawings, the thickness of lines, layers and / or regions may be exaggerated for clarity.

[0031] It goes without saying that when an element is referred to as being "connected" or "coupled" to other elements, the elements may be connected or coupled directly or through one or more intermediate elements. When "or" is used to combine two elements A and B, this is understood to disclose all possible combinations, i.e. only A, only B, and A and B, unless otherwise explicitly or implicitly defined. Alternative expressions for the same combination are "at least one of A and B" or "A and / or B". The same applies to combinations of more than two elements.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) are used herein with their common meaning in the art to which examples belong.

[0033] Figure 1a A flow chart of an embodiment of a method for adjusting time synchronization between a mobile device 20 and a transceiver module 10 of a plurality of transceiver modules is shown. The method is performed by the transceiver module. In particular, the method can be performed by each transceiver module. For example Figure 1b A plurality of transceiver modules 10 are shown, which can respectively perform the method. The method comprises listening 120 for time synchronization signals of other transceiver modules of the plurality of transceiver modules in at least some of the plurality of time periods. Each of the plurality of time periods is assigned to one of the plurality of transceiver modules. The method further comprises adjusting 140 the time synchronization if the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module. The method further comprises sending 150 the time synchronization signal for the other transceiver modules based on the time synchronization between the mobile device and the transceiver module.

[0034] Figure 1b FIG. 1 is a block diagram of an embodiment of a corresponding transceiver module 10, which is configured to adjust time synchronization. The transceiver module 10 includes one or more processors 12 and one or more transceivers 14 coupled to the one or more processors. The processing functions of the transceiver module can be provided by the processor, while the communication is performed through the one or more transceivers. The transceiver module is configured to perform Figure 1aThe method of adjusting the time synchronization between the mobile device 20 and the transceiver module 10. In particular, the transceiver module is configured to listen to the time synchronization signals of other transceiver modules in the plurality of transceiver modules in at least some of the plurality of time periods through the transceiver. The plurality of transceiver modules include the transceiver module. The transceiver module is configured to adjust the time synchronization if the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module. The transceiver module is configured to send the time synchronization signal to the other transceiver modules through the transceiver based on the time synchronization between the mobile device and the transceiver module.

[0035] Embodiments of the present disclosure relate to methods, computer programs, and transceiver modules for adjusting time synchronization between a mobile device and one of a plurality of transceiver modules. In the scenarios described herein, the focus is on direct or indirect time synchronization of a mobile device with a plurality of transceiver modules (such as each one). For example, such time synchronization may be desired in a vehicle scenario. For example, a vehicle may include a plurality of transceiver modules. The plurality of transceiver modules may, for example, be arranged at different locations in the vehicle. For example, one transceiver module each may be arranged on the four outer corners of the vehicle (for example, in a bumper) and one or more transceiver modules may be arranged in an interior space of the vehicle. In Figures 5a to 6b An example for this is shown in , in which the multiple transceivers respectively include six transceivers. In general, the transceiver module is configured to communicate via wireless transmission technology. In particular, the proposed time synchronization signal is a wireless time synchronization signal. The transceiver module can be configured, for example, to communicate via a first (wireless) transmission technology, such as ultra-wideband transmission technology (UWB). At least one subset of the transceiver can also be configured to communicate via a second (wireless) transmission technology, such as a Bluetooth-based transmission technology, such as low-energy Bluetooth (BLE). The corresponding transceiver module can include a separate transceiver for each transmission technology, such as a separate transceiver for UWB and BLE (or a transceiver only for UWB if only UWB is supported). In the transceiver module, a transceiver (or a transceiver) can also be connected to a vehicle network such as a controller area network bus (CAN bus) or a local interconnect network (LIN) for wired communication, such as communicating with a vehicle controller. The mobile device can be a mobile phone, such as a programmable mobile phone (also a smart phone). Alternatively, the mobile device can be, for example, a so-called "wearable" (device) (a mobile device that can be worn on the body), or a remote control key (key fob) for the vehicle. In some embodiments, the mobile device can be configured to communicate with the transceiver module via UWB and / or BLE. The communication between the mobile device and a plurality of transceiver modules (i.e. also with the transceiver modules) can be provided for determining the position of the mobile device relative to the vehicle.

[0036] In principle, two different time synchronization signals may be used for time synchronization: a time synchronization signal of another transceiver module (besides the mobile device) and a time synchronization signal of the mobile device. Accordingly, the method may optionally include listening 110 for the time synchronization signal of the mobile device within a predefined period. The predefined period is Figures 2 to 6b It is summarized as "UWB ranging time window". In this time window, two time intervals are of particular concern: one is the time interval for receiving the time synchronization packet (hereinafter also referred to as PREPOLL signal), and the other is the time interval for receiving the ranging start packet (hereinafter also referred to as POLL signal). Figure 5a and 6b Only the time intervals for UWB communication are shown in the figure. Accordingly, the predefined period may be a predefined period for receiving a UWB-based time synchronization signal. As an alternative, the time synchronization signal of the mobile device may also be a BLE-based time synchronization signal. Accordingly, the predefined period may be a predefined period for receiving a BLE-based time synchronization signal. Combinations are also possible. Thus, the transceiver module may listen to the time synchronization signal of the mobile device in one predefined period for receiving a BLE-based time synchronization signal (of the mobile device) and in (another) predefined period for receiving a UWB-based time synchronization signal of the mobile device. However, this implementation possibility is not described in the figure. Figures 2 to 6b , where BLE time synchronization is used to roughly define the time period for receiving UWB time synchronization packets (e.g. Figure 2 The time synchronization signal of the mobile device may be based on ultra-wideband transmission technology or Bluetooth transmission technology (e.g., BLE). In conjunction with the present disclosure, when the receiving component of the transceiver of the transceiver module is activated and ready to receive signals, it can be referred to as "listening". In other words, "listening" corresponds to the activation of the receiving component of the transceiver of the transceiver module. In addition, the corresponding time synchronization signal may correspond to a time synchronization packet transmitted by the corresponding transmission technology.

[0037] The method further comprises listening 120 for time synchronization signals of other transceiver modules of the plurality of transceiver modules in at least some of the plurality of time periods. Here each of the plurality of time periods is assigned to one of the plurality of transceiver modules. Thus, “listening” may relate to those of the plurality of time periods that are assigned to other transceiver modules of the plurality of transceiver modules. The corresponding plurality of time intervals are Figures 3 to 6bIn FIG. 1 , the time slots are shown as UWB time synchronization time slots. For example, the time synchronization signal of the other transceiver module may be based on UWB transmission technology.

[0038] The method further comprises: if the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module, adjusting 140 the time synchronization. Herein the "estimated accuracy of the time synchronization" may mean how high the difference between the time synchronization of the transceiver module or the time synchronization signal and the time used by the mobile device can be at most. Herein the accuracy of the time synchronization between the mobile device and the transceiver module may decrease over time until said accuracy is increased again by time synchronization with the mobile device by means of the time synchronization signal of the mobile device (or by the transmission of the time synchronization signal of another transceiver module).

[0039] For making the decision, it can be determined on the one hand how high the estimated accuracy of the (current) time synchronization between the mobile device and the transceiver module is and on the other hand how high the estimated accuracy of the received time synchronization signal is. For the latter, the respective time synchronization signal can for example comprise information about how high the estimated accuracy of the respective time synchronization signal is. In other words, the received and transmitted time synchronization signals can comprise information about the estimated accuracy of the respective time synchronization signal.

[0040] For the current time synchronization, the estimated accuracy can be determined by the transceiver module itself. The estimated accuracy of the time synchronization can initially be based on the estimated accuracy of the time synchronization signal from which the time synchronization is derived. The estimated accuracy can now be continuously depreciated according to the maximum drift of the timers of the mobile device and the corresponding transceiver module. Therefore, the method can include adjusting 130 the estimated accuracy of the time synchronization based on the time span since the last adjustment of the time synchronization, based on the estimated accuracy of the time synchronization signal based on which the last time synchronization adjustment was based, and based on the accuracy of the timer of the transceiver module (and / or the timer of the mobile device). The estimated accuracy of the time synchronization can be continuously depreciated (i.e. reduced) based on the time span since the last time synchronization adjustment, based on the estimated accuracy of the time synchronization signal based on which the last time synchronization adjustment was based, and based on the accuracy of the timer of the transceiver module (and / or the timer of the mobile device). The accuracy can also be used as a trigger for listening to the corresponding time synchronization signal. For example, if the accuracy of the time synchronization is lower than a threshold, the time synchronization signal (of the mobile device or other transceiver module) can be listened to 110; 120.

[0041] If these prerequisites are met, the time synchronization is adjusted 140. The time synchronization can be derived from the time synchronization signal, for example. For example, the time synchronization signal can be in a fixed relationship with the time synchronization, which is achieved, for example, in that the time synchronization signal is sent (and therefore also received) at a fixed time point (time interval) relative to the time synchronization. The method can therefore include deriving the time synchronization based on a predefined time relationship between the time synchronization signal and the time synchronization.

[0042] The transceiver module not only receives time synchronization signals from other transceiver modules or from the mobile device, but also transmits a time synchronization signal itself, which can be received by other (or at least some other) transceiver modules if necessary. The method thus comprises sending 150 a time synchronization signal to other transceiver modules based on the time synchronization between the mobile device and the transceiver module. For this purpose, the transceiver module can use the time period allocated to the transceiver module.

[0043] In at least some embodiments, time synchronization is adjusted so that the transceiver module is synchronized with the mobile device as much as possible. If the accuracy of time synchronization is high enough, the transceiver module can more accurately estimate the time point when the mobile device or other transceiver modules send signals related to the transceiver module. Accordingly, the transceiver module can control the receiving components of the transceiver of the transceiver module accordingly. For example, the method may include adjusting 160 the signal receiving time period of the transceiver of the transceiver module based on the adjusted time synchronization. For example, the receiving component of the transceiver can be activated within the signal receiving time period and otherwise deactivated. Accordingly, the method may include, for example, selectively activating the receiving component of the transceiver based on time synchronization when the accuracy of time synchronization is high enough. Here, the signal receiving time period of the transceiver for receiving the positioning signal from the mobile device can be adjusted based on the adjusted time synchronization. For example, the transceiver can be a UWB transceiver and the signal receiving time period of the transceiver for receiving the UWB positioning signal can be adjusted. For example, the signal receiving time period of the transceiver for receiving the UWB positioning signal can be defined as one or more relevant time periods. Outside this time period, the receiving component can be deactivated, for example.

[0044] In an embodiment, the one or more processors 12 may correspond to any controller or processor or programmable hardware component. For example, the one or more processors 12 may also be implemented as software, which is programmed for corresponding hardware components. In this regard, the one or more processors 12 may be implemented as programmable hardware with corresponding adapted software. Any processor, such as a digital signal processor (DSP), may be used here. The embodiments are not limited to a specific type of processor here. It is conceivable that any processor or multiple processors are used to implement the one or more processors 12.

[0045] In some embodiments, the one or more transceivers 14 may include typical transmitting or receiving components, which may include, for example, one or more antennas, one or more filters, one or more mixers, one or more amplifiers, one or more duplexers, one or more diplexers, etc.

[0046] Further details and aspects of the method and transceiver module are combined before or after (e.g., in Figures 2 to 6b The method or transceiver module may include one or more additional optional features, which correspond to one or more aspects of the proposed solution or the example described above or below.

[0047] In at least some embodiments, the transceiver module is a transceiver module of a vehicle. In the following, it is assumed that the transceiver module or the transceiver device installed in the vehicle is configured for communication via ultra-wideband communication (UWB) according to IEEE 802.15.4. However, the principles shown can also be applied to other wireless transmission technologies and protocols.

[0048] Since the radio interface for positioning according to IEEE 802.15.4 is supported by all transceivers installed in the vehicle, it can also be used in addition to positioning to distribute time synchronization information between the transceivers (transceiver modules) installed in the vehicle. Since the distance measurement method standardized in IEEE 802.15.4 is essentially based on the precise measurement of the time difference between the sending and receiving of radio messages, it provides the characteristics required for the time synchronization of the transceivers installed in the vehicle - unlike vehicle bus systems designed only for data communication. Although there are vehicle bus systems suitable for time synchronization, the commonly used CAN and LIN systems are generally not suitable for this.

[0049] The synchronization protocol shown below is based on the following functional principles:

[0050] Each transceiver device installed in the vehicle periodically sends locally available time synchronization information about the mobile transceiver device (as a time synchronization signal) to all other (further) transceiver devices installed in the vehicle (as a broadcast).

[0051] Each transceiver installed in the vehicle periodically receives time synchronization information about the mobile transceiver from all other transceivers installed in the vehicle and compares each time synchronization information with the locally available time synchronization information. If the received time synchronization information is of higher quality (i.e., has a higher estimated accuracy) than the corresponding locally available time synchronization information, the receiving transceiver replaces the local time synchronization information (i.e., local time synchronization) with the received higher quality time synchronization information.

[0052] Each transceiver installed in the vehicle re-evaluates the quality of the locally available time synchronization information for each periodic transmission event in order to be able to make a statement about the quality of the locally available time synchronization information. For this purpose, the statement about the information quality is reduced linearly over time by X ppm (parts per million) in order to take into account the maximum deviations guaranteed in the IEEE 802.15.4 standard of the drift of the quartz oscillator in the mobile transceiver compared to the transceiver installed in the vehicle.

[0053] The following advantageous basic properties apply to the synchronization protocol shown below:

[0054] If there is no direct connection between two transceiver devices installed in a vehicle, but there is an indirect connection through one (or more) other transceiver devices, the time synchronization information is transmitted with a delay of one (or more) cycles.

[0055] If there are multiple indirect connections between two transceiver devices installed in the vehicle, the time synchronization information is transmitted over the shortest path (ie the indirect connection with the shortest delay).

[0056] If there is a direct but unstable connection between two transceiver devices installed in the vehicle (ie the data communication via the radio channel is faulty or occasionally interrupted), the time synchronization transmission is delayed until error-free data transmission is restored for the first time.

[0057] An exemplary implementation is shown below.

[0058] Some embodiments of the present disclosure generally relate to the distribution of time synchronization information via UWB. In some embodiments, UWB can be used to establish time synchronization between a mobile device and a transceiver module. The time synchronization can then be shared with other transceiver modules.

[0059] Figure 2A timing diagram of time synchronization between a mobile device and a transceiver module is shown. Dual time synchronization is used here. On the one hand, time synchronization is achieved by low-energy Bluetooth to achieve rough time synchronization. Based on the rough time synchronization, the transceiver module can determine a rough time interval, within which the transceiver module can receive a so-called PREPOLL signal (pre-inquiry signal, time synchronization signal / packet). The time frame for UWB ranging is defined according to the PREPOLL signal. Within the time frame for UWB ranging, the mobile device sends a POLL signal (inquiry signal, ranging start signal / packet) that should be received by the transceiver module. In addition, a time period is defined for each transceiver module within the time frame (here marked as "anchor point 1" to "anchor point 6", this example is based on six transceiver modules, which are also currently referred to as anchor points). At the end of the UWB ranging time frame, the mobile device sends a "FINAL" signal, followed by a "FINAL_DATA" signal containing the distance measurement result. Edge synchronization is performed between the PREPOLL signal and the UWB ranging time frame and from the UWB ranging time frame to the next POLL signal.

[0060] Each anchor point shall acquire a PREPOLL signal via UWB to participate in ranging, e.g., open an RX time frame / window around the PREPOLL signal in each ranging cycle (e.g., a signal / data reception time frame / time window for receiving data via the corresponding transceiver). The size of the RX time frame depends on the BLE time synchronization (accuracy: approximately 1ms). Each anchor point that has received a PREPOLL signal via UWB shall open an RX time frame around the POLL signal in each ranging cycle. Each anchor point that has received a POLL signal in the current measurement cycle shall use POLL to synchronize with the UWB MAC (Media Access Control) time grid (accuracy: ~1μs), respond to the POLL signal in the response time slot set by the anchor point for this purpose, and open an RX time window around the time intervals FINAL and FINAL_DATA in the current measurement cycle. Each anchor point that has not received a POLL signal in the current measurement cycle shall increase the UWB RX window size by 125-200ppm (depending on the implementation) in the next cycle.

[0061] The current example is based on time synchronization between the mobile device and the transceiver module and further distributing the time synchronization to other transceiver modules.

[0062] Figure 3A timing diagram of time synchronization between a mobile device and a transceiver module and between different transceiver modules is shown. Each anchor point with a duty cycle less than 100% can transmit a time synchronization data packet (i.e., a time synchronization signal, for example) within its dedicated UWB time synchronization time interval. In the example above with six transceiver modules (anchor points), the time interval of the first transceiver module can be the first time interval after FINAL_DATA, the time interval of the second transceiver module can be the second time interval after FINAL_DATA, and so on (in the same fixed order as in ranging). The transceiver modules receive, process and forward time synchronization information from each other, and an RX time window for receiving time synchronization packets of other transceiver packets is opened. In an extended scheme, each anchor point in the same ranging cycle can avoid receiving time synchronization packets of other anchor points through a PREPOLL signal or a POLL signal. In another extended scheme, a transceiver module whose current RX time window (the time window is based on the estimated accuracy of time synchronization) is less than a threshold value can avoid receiving time synchronization packets of other transceivers.

[0063] The time synchronization information of all ranging sessions collected by the transceiver module, such as the time synchronization signal, can be sent via a UWB data packet. The data packet can be periodically sent in the time slot of the time grid after the (or each) ranging cycle. The transceiver module as the first responder in the ranging session sends a time synchronization packet in the first time interval after the time interval allocated for the FINAL_DATA packet of the ranging session. Similarly, the transceiver module as the second responder in the ranging session sends a time synchronization packet in the second time interval after the time interval allocated for the FINAL_DATA packet of the ranging session. Similarly, the nth transceiver module as the nth responder in the ranging session sends a time synchronization packet in the nth time interval after the time interval allocated for the FINAL_DATA packet of the ranging session. Here, 1≤n≤the number of responders, and the number of responders is transmitted to each transceiver module via the vehicle bus when each ranging session is established. If no time synchronization information is available at a transceiver module, the transmission of the time synchronization data packet by the corresponding transceiver module can be stopped until time synchronization information is available at the corresponding anchor point. Figure 3 exemplarily shows the allocation of the number of responders=6.

[0064] Figure 4 An exemplary packet format of an exemplary UWB time synchronization data packet / signal is shown. The time synchronization packet to be sent by each transceiver module for a specific ranging session within a time interval may have the same PHY (physical layer) and MAC configuration as the PREPOLL packet of the ranging session. In particular, the same SYNC pilot code (synchronization pilot code) and the same SFD configuration (start frame delimiter) may be used.

[0065] The following unencrypted PSDU (Physical Layer Service Data Unit) can be used for time synchronization packets:

[0066] The PSDU may include an IEEE MAC Header (MHR) of 10 bytes. The IEEE-MAC useful data may include time synchronization information and the estimated accuracy and / or instantaneous accuracy of the time synchronization information when the RMARKER of the time synchronization transmission is transmitted. In addition, an IEEE MAC-Footer (MFR) of 2 bytes may be used.

[0067] The MHR field can be Figure 4 The setting shown, where "<<" and ">>" refer to bitwise shift operations to the left and right and "&" and "|" refer to bitwise logical and operations or OR operations. The MHR here can include a 2-byte frame control field, an optional sequence number, a 2-byte target Pan ID (e.g., a UWB session identifier shifted 16 bits to the right), a 2-byte target address (e.g., an anchor address shifted 4 bits to the left | 0x0f), a 2-byte source Pan ID (e.g., a UWB session identifier & 0xffff), and a 2-byte source address (e.g., an anchor address shifted 4 bits to the left | an anchor identifier). Additional security headers and IEs (information elements) can also be used here. Information elements are special standardized data fields that can be transmitted in a MAC header for standard applications and in which each receiver knows what the standardized meaning of the data is. This is in contrast to the useful data part, in which arbitrary data can be transmitted, but the receiver needs a description of the format and meaning to decode it. In addition, a similar format can be used for Bluetooth LE time synchronization.

[0068] The anchor point identifier can be set according to the time interval of the transceiver module, that is, the first responder is 1, the second responder is 2, and so on.

[0069] The useful data contains time synchronization information and information about the accuracy of the time synchronization information. Here, for example, the RMARKER in the IEEE 802.15.4 standard is used as a time reference. The time synchronization information is based on the timer of the transmitting transceiver module. The accuracy can be adjusted and the size of the RX time window on the receiving transceiver module side can be determined at each transmission. Each transceiver module can receive and process the UWB time synchronization packets of other transceiver modules according to the following method.

[0070] For example, each anchor point listens to incoming UWB packets from other anchor points in the same way as it listens to UWB packets from smartphones (mobile devices). The dynamic opening of the UWB RX window can be applied to the reception of time synchronization packets by all other transceiver modules.

[0071] For example, the transceiver module will (only) process time synchronization packets that have a session ID that matches the ranging session configured in the transceiver module and a matching transceiver address, such as Figure 4 As shown in the MAC-Header-PAN-ID field.

[0072] After successfully receiving the UWB time synchronization data packet from the other transceiver module, the receiving transceiver module performs the following operations:

[0073] 1.RMARKER reception is time-stamped by the local clock, resulting in an accuracy of acc RMARKER Timestamp t RMARKER .

[0074] 2. The PSDU timestamp and precision fields can be decoded and stored as t ANDERER_ANCHOR and acc ANDERER_ANCHOR .

[0075] 3. If acc RMARKER +acc ANDERER_ANCHOR If the estimated accuracy of the time synchronization of the receiving transceiver module is less than (better than) that of the receiving transceiver module, the receiving transceiver module should use t ANDERER_ANCHOR Replaces the previous time synchronization.

[0076] Below is an example of adjusting time synchronization based on a BLE connection with a phone / mobile device. Figure 5a An exemplary network diagram showing a network with a mobile device and multiple transceiver modules (currently referred to as anchors 1 to 6). The arrows between the anchors show which anchors successfully communicate with each other, if there is a connection with less latency (currently for example between anchors 1 and 4), not all connections will be used. The numbers between the anchors indicate the latency resulting from the order of the time intervals. Figure 5a An example of a network diagram is shown, including an exemplary number of anchor points, an exemplary UWB link (between transceiver modules), when transceiver module 5 is performing BLE time synchronization with a mobile device (arrow between mobile device and anchor point 5). The UWB link weight shows the number of ranging cycles after receiving a UWB time synchronization packet until time synchronization information is sent by each individual anchor point. The dashed UWB link between two transceivers is available, but not used.

[0077] Figure 5b An exemplary timing diagram showing time synchronization between a mobile device and a transceiver module and between different transceiver modules, with initial time synchronization being performed via Bluetooth Low Energy. Figure 5b by Figure 5a Based on the network diagram, and accordingly Figure 6b by Figure 6aAssuming that all transceiver modules try to receive the ranging session PREPOLL on a 100% open UWB RX window before receiving the time synchronization information via BLE or UWB, Figure 5b The sequential application of received time synchronization information is shown to reduce the duration of the UWB-RX window of the exemplary network diagram above.

[0078] exist Figure 5b and 6b In the figure, the time frame in which the corresponding transceiver listens for signals is indicated by hatching, while the time interval in which data is sent or received is indicated by another hatching. Figure 5b In the example of FIG. 5 , BLE time synchronization is performed between the mobile device and the anchor point (transceiver module) 5 (via the BLE time synchronization signal of the mobile device). Therefore, it is not necessary for the anchor point 5 to listen on the entire UWB ranging time frame, but the listening can be limited to the PREPOLL signal, the POLL signal, the FINAL signal and the FINAL_DATA signal, so that the receiving component can be turned off during this period. The anchor point 5 is assigned to the fifth time interval in the UWB time synchronization time frame, so the anchor point 5 sends the time synchronization signal in this time frame, as shown in FIG. Figure 5a As can be seen in the figure, the signal is received and processed by anchor point 6. Anchor point 6 in turn sends other time synchronization signals, which are received and processed by anchor point 2. Therefore, in the next (n+1th) UWB ranging time window, anchor points 2, 5 and 6 can control the receiving components in a targeted manner so that the receiving components of the corresponding (UWB) transceivers only work in the time intervals of PREPOLL, POLL, FINAL and FINAL_DATA. In the UWB time synchronization time window after the n+1th UWB ranging time interval, anchor point 2 sends a time synchronization signal, which is received and processed by other transceiver modules 1 and 3. In the same UWB time synchronization time window, anchor point 3 immediately sends the received information to transceiver module 4. Therefore, all anchor points can control the receiving components in a targeted manner so that the receiving components of the corresponding (UWB) transceivers only work in the time intervals of PREPOLL, POLL, FINAL and FINAL_DATA.

[0079] In another example, a continuous BLE and UWB connection with a cell phone / mobile device is illustrated. Figure 6a An exemplary network diagram showing a network with a mobile device and multiple transceiver modules. Figure 5a Network diagram of , where UWB time synchronization is also performed between the mobile device and the anchor point 2. Figure 6aAn example of a network diagram is shown, including an exemplary numbering of anchor points, exemplary UWB links (between anchor points and between a mobile device and anchor point 2), when anchor point 2 receives the first UWB time synchronization information, while all other anchor points are in a state of synchronization with the BLE time synchronization information through the previous exchange of UWB time synchronization packets generated by the BLE time synchronization process of anchor point 5. The UWB link weight (between anchor points) shows the number of ranging cycles until the time synchronization information is sent by each individual anchor point after the UWB time synchronization data packet is received. The UWB link between anchor points 1 and 4 is available, but not used.

[0080] Assuming that all transceiver modules have received the BLE time synchronization information from anchor point 5 through the earlier UWB time synchronization packet exchange and attempt to receive the ranging session PREPOLL with a reduced UWB RX window, Figure 6b The sequential application of the improved time synchronization information of anchor point 2 is shown as a result of PREPOLL reception. Figure 6b An exemplary timing diagram showing time synchronization between a mobile device and a transceiver module and between different transceiver modules, wherein Figure 5b Compared to the previous example, additional time synchronization is performed via UWB. Figure 6b In the example of , anchor point 2 receives a PREPOLL signal and a POLL signal from a mobile device, sends a response within the time interval of the UWB ranging time window assigned to it, and receives FINAL and FINAL_DATA signals from the mobile device. Then, anchor point 2 sends a time synchronization signal in the time interval of the UWB time synchronization time window assigned to it, which is received and processed by anchor points 1, 3 and 6 (and in the case of anchor point 1, it is applied in the next time window). Based on this, anchor point 3 sends a time synchronization signal, which is received and processed by anchor point 4, and anchor point 6 sends a time synchronization signal, which is received by anchor point 5 and applied there in the subsequent UWB time synchronization time window. In the next UWB ranging time window, all anchor points can now listen to the PREPOLL or POLL signal (in the case of anchor point 2) in a targeted manner, and since the time synchronization is now accurate enough, it is avoided to listen to the time synchronization signals of other anchor points / transceiver modules.

[0081] The aspects and features described in conjunction with one or more of the previous detailed examples and figures may also be combined with one or more other examples to replace the same features in another example or to additionally introduce the features into another example.

[0082] Examples may also be computer programs with program codes for performing one or more of the above methods or associated with the computer programs when they are executed on a computer or processor. The steps, operations or processes of the various methods described above may be performed by a programmed computer or processor. Examples may also include program storage devices, such as digital data storage media, which are readable by a machine, a processor or a computer and encode machine-executable, processor-executable or computer-executable instruction programs. These instructions perform some or all of the steps of the above methods or cause them to be performed. The program storage device may, for example, include or may be a digital memory, a magnetic storage medium, such as a disk and a tape, a hard drive, or an optically readable digital data storage medium. Other examples may also include a computer, a processor or a control unit programmed to perform the steps of the above methods, or a (field) programmable logic array (FPLA) or a (field) programmable gate array (FPGA) programmed to perform the steps of the above methods.

[0083] The description and drawings only represent the principles of the present disclosure. In addition, all examples listed herein are clearly used for illustrative purposes only in principle to help readers understand the principles of the present disclosure and the design solutions contributed by the inventors to improve the technology. All statements about the principles, aspects and examples of the present disclosure and their specific examples include their equivalents.

[0084] The functions of the different elements shown in the drawings, including the functions of each functional block referred to as "means", "means for providing a signal", "means for generating a signal", etc., may be implemented in the form of dedicated hardware, such as "signal provider", "signal processing unit", "processor", "control means", etc., as well as hardware that is capable of executing software in conjunction with related software. When provided by a processor, the functions may be provided by a single dedicated processor, a single shared processor, or multiple independent processors, some or all of which may be shared. However, the terms "processor" or "control means" are by no means limited to hardware that can only execute software, but may include digital signal processor hardware (DSP hardware), network processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), read-only memories (ROMs), random access memories (RAMs), and non-volatile storage devices for storing software. Other hardware, conventional and / or customer-specific may also be included.

[0085] A block diagram may represent, for example, a rough circuit diagram that implements the principles of the present disclosure. Similarly, a flow chart, sequence diagram, state transition diagram, pseudo code, etc. may represent various processes, operations, or steps that are, for example, substantially displayed in a computer-readable medium and are therefore executed by a computer or processor, whether or not such a computer or processor is explicitly shown. The methods disclosed in the specification or claims may be implemented by a component that includes means for performing each step of these methods.

[0086] It goes without saying that, unless otherwise stated explicitly or implicitly, for example for technical reasons, multiple steps, processes, operations or functions disclosed in the specification or claims should not be interpreted as being performed in a specific order. Therefore, the disclosure of multiple steps or functions does not limit them to a specific order, unless these steps or functions are not interchangeable for technical reasons. In addition, in some examples, a single step, function, process or operation may include and / or be decomposed into multiple sub-steps, functions, processes or operations. Unless explicitly excluded, these sub-steps may be included and constitute part of the disclosure of the single step.

[0087] In addition, the following claims are hereby incorporated into the detailed description, and each claim can stand on its own as a separate example. Although each claim can stand on its own as a separate example, it should be noted that although a dependent claim in the claims may refer to a specific combination with one or more other claims, other examples may also include a combination of a dependent claim with the technical solutions of any other dependent or independent claim. Unless it is stated that a specific combination is not considered, these combinations are explicitly proposed here. In addition, features of a claim should also be included in any other independent claim, even if the claim does not directly refer to the independent claim.

Claims

1. A method for adjusting time synchronization between a mobile device and a transceiver module among a plurality of transceiver modules, the method being performed by the transceiver module, the method comprising: listening (120) for time synchronization signals of other transceiver modules of the plurality of transceiver modules in at least some of a plurality of time periods, each of the plurality of time periods being allocated to a transceiver module of the plurality of transceiver modules; If the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module, adjusting (140) the time synchronization; and sending (150) a time synchronization signal to the other transceiver modules based on the time synchronization between the mobile device and the transceiver module, wherein the received and transmitted time synchronization signals comprise information about an estimated accuracy of the respective time synchronization signals, wherein the method comprises adjusting (130) the estimated accuracy of the time synchronization based on a time span since the last adjustment of the time synchronization, based on an estimated accuracy of the time synchronization signal based on which the last adjustment of the time synchronization was made, and based on an accuracy of a timer of the transceiver module.

2. The method according to claim 1, wherein: The method includes listening (110) for a time synchronization signal of a mobile device for a predefined period of time.

3. The method according to claim 1 or 2, wherein: If the accuracy of the time synchronization is lower than the threshold, a time synchronization signal is listened to (110; 120).

4. The method according to claim 1 or 2, wherein: The method includes adjusting (160) a signal reception time period of a transceiver of the transceiver module based on the adjusted time synchronization.

5. The method according to claim 4, wherein: A signal reception time period of the transceiver for receiving a positioning signal from a mobile device is adjusted based on the adjusted time synchronization.

6. The method according to claim 2, wherein: The time synchronization signal of the other transceiver modules is based on ultra-wideband transmission technology, and / or the time synchronization signal of the mobile device is based on ultra-wideband transmission technology or Bluetooth transmission technology.

7. The method according to claim 1 or 2, wherein: The plurality of transceiver modules are disposed at different locations of the vehicle.

8. A transceiver module (10), the transceiver module having one or more processors (12) and one or more transceivers (14), the transceiver module being configured to adjust time synchronization between a mobile device (20) and the transceiver module (10) by: Listening, by the transceiver, time synchronization signals of other transceiver modules in a plurality of transceiver modules in at least some of a plurality of time periods, each of the plurality of time periods being allocated to a transceiver module in the plurality of transceiver modules, the plurality of transceiver modules including the transceiver module; If the received time synchronization signal has a higher estimated accuracy than the time synchronization between the mobile device and the transceiver module, adjusting the time synchronization; and Sending a time synchronization signal to the other transceiver modules through the transceiver based on the time synchronization between the mobile device and the transceiver module, in, The received and transmitted time synchronization signals include information about an estimated accuracy of the corresponding time synchronization signal, wherein the estimated accuracy of the time synchronization is adjusted based on a time span since the last adjustment of the time synchronization, based on an estimated accuracy of the time synchronization signal based on which the time synchronization was last adjusted, and based on the accuracy of a timer of the transceiver module.

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