Device and method for calibrating a radio-based position determining device

[0001] The field of the present invention includes the calibration of the device for determining the position included in the radio navigation system, and in particular the calibration dependent on the strength of the received radio signals.

[0002] Various technologies are available to determine the location of portable end devices. The most known localization / navigation system for outdoor applications is the satellite-based satellite navigation system (GPS). There are various approaches to determining location and navigation inside buildings, such as systems based on the use of infrared, RFID (Radio Frequency Identification) systems, as well as field strength analysis in IEEE 802.11 WLAN (Wireless Local Area Network) networks. Currently, the GPS system works reliably only outside. Newer extensions, such as high-sensitivity receivers or A-GPS (Assisted GPS), are an attempt to use this technology also indoors. The AGPS system uses a GPS satellite navigation system in connection with the reception of the so-called support information from the mobile network. However, these technologies do not yet have adequate average accuracy. Infrared and RFID based systems are usually not available everywhere, and their operation depends on meeting certain conditions.

[0003] WLAN technology in accordance with IEEE 802.11 has become a standard in the field of wireless network communication. It is constantly developed, both in terms of data transmission speed and range. Proven standards and standards still in the planning phase enable broadband data transfer at high speed and are characterized by a high degree of integration enabling low equipment prices. Currently available palmtops (PDA = Personal Digital Assistants) and smartphones usually have built-in wireless interfaces, like the mentioned WLAN interface. In addition, the Bluetooth standard is often used, and WiMAX technology may be used in the future.

[0004] In the case of WLAN technology, commercial public WLAN access points (so-called hotspots) are in the meantime in many places with a large number of visitors. The growing spread of broadband Internet access (e.g. using DSL technology) has led to the spread of WLAN as an affordable home network technology also among private users. A number of studies have shown that networks

WLANs are now widely available in downtown areas, and their numbers even sometimes exceed real demand. This applies in particular to places of everyday life and tourist attractions. Therefore, WLANs can be the basic technology for determining the location of mobile devices. In the future, other technologies will certainly be used to which the presented concept of the invention can be extended.

[0005] The location of portable terminal devices in WLANs can generally be determined by analyzing base stations received by a portable terminal device (hotspots or access points), in which, for example, the strength of the signals received by the terminal device is determined. However, WLAN signals are heavily shielded by buildings and other obstacles, and especially in urban areas with extensive WLAN infrastructure there are usually no ideal anechoic conditions due to location. This means that you cannot directly determine the distance of the mobile terminal to the base station or second party based on the measured signal strength or field strength.

[0006] For positioning systems based on WLANs, the so-called "Received-signal-strength fingerprinting". The above radioidentification method is based on the assumption that the strength of radio signals from many radio beacons that are or can be received at a given location clearly indicates the current location or position. If there are reference data containing the names of the transmitters that are or can be received at a given reference time in a certain number of reference places or positions, and the strength of the relevant radio signals, a set of current measured values ​​(names of radio transmitters with the corresponding signal strength values) allows determining the current position mobile device by comparing the current measured values ​​with the reference values ​​contained in the data. As part of said matching, for each reference point, it is determined to what extent the previously recorded measured values ​​or reference values ​​are similar to the current measured values ​​at the current position. The most similar reference points form the basis for the estimate value of the location where the mobile terminal is currently located.

[0007] European patent application EP 1 795 912 A1 describes a technique for determining the location of a target in a "wireless communication environment". The data model models multiple random points or sample points. Each point of the samples includes a given place along with a set of expected signal values. Signal values ​​are observed where the target is located. Based on the observed signal values ​​and the set of significance indicators, the current set of significant sample points is determined, which is then used together with the observed signal values ​​to estimate the location of the target.

[0008] For reference data, it is possible to experimentally determine the strength of the radio beacons signals that can be received at a reference position between individual moments of reference measurements. As a result, we receive data containing a list of radio transmitters (access points) with appropriately assigned receiving strength and field strength quality for each geographical reference position. This list associated with a given reference position is also referred to as the reference measurement package or the reference package (RP). For a WLAN, this reference data might look like this:

<td>RID</td><td>MOTHER</td><td>RSSI</td><td>PGS</td><td>X</td><td>Y</td><td>FROM</td><td>MAPNR</td><td>CREATED</td>

<td> 1</td><td>00.OD.54.9E. 17.81</td><td> 46530</td><td> 100</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>00.00.54.9E.1A.BA</td><td> 67260</td><td> 90</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>00.00.54.9E.1D.64</td><td> 72002</td><td> 88</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>OO.OE.6A.D3.B9.8B</td><td> 59531</td><td> 100</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>00.0F.A3.10.07.6C</td><td> 46464</td><td> 96</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>00.0F.A3.10.07.FB</td><td> 74488</td><td> 94</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 1</td><td>00.0F.A3.10.09.SF</td><td> 72375</td><td> 97</td><td> 5795</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:42</td>

<td> 2</td><td>00.00.54.9E.17.81</td><td> 54138</td><td> 100</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>00.00.54.9E.18.1D</td><td> 76560</td><td> 11</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>OO.OD.54.9E.1 A.BA</td><td> 62318</td><td> 94</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>00.00.54.9E.1D.64</td><td> 71348</td><td> 96</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>OO.OE.6A.D3.B9.8B</td><td> 45393</td><td> 100</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>00.0F.A3.10.07.6C</td><td> 66853</td><td> 96</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>00.0F.A3.10.07.FB</td><td> 72251</td><td> 100</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 2</td><td>00.0F.A3.10.09.5F</td><td> 70990</td><td> 90</td><td> 14399</td><td> 15451</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.00.54.9E.17.81</td><td> 58291</td><td> 100</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.00.54.9E.18.1D</td><td> 78610</td><td> 68</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.00.54.9E.1 A.BA</td><td> 62153</td><td> 98</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.00.54.9E.1D.64</td><td> 64187</td><td> 90</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>OO.OE.6A.D3.B9.8B</td><td> 32851</td><td> 100</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.0F.A3.10.07.6C</td><td> 69006</td><td> 96</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.0F.A3.10.07.FB</td><td> 71749</td><td> 92</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>OO.OF.A3.10.09.5F</td><td> 71482</td><td> 83</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

<td> 3</td><td>00.OF.A3.10.09.80</td><td> 71000</td><td> 40</td><td> 24583</td><td> 15627</td><td> 150</td><td> 0</td><td> 12.03.07 12:43</td>

[0009] The table contains the following information:

• reference position identifier (ID) (in this case: 1, 2, 3) • MAC addresses of radio transmitters received in a given reference position • receiving strength of field strengths of radio transmitters that can be received in the reference position (RSSI = Received Signal Strength Indicator; e.g. the value of 46.56 means 46.56 dBm) • reference positions in Cartesian metric coordinates (x, y, z), and • the moment or time stamp of the recorded measured values.

[0010] The optional PGS values ​​("percentage seen") determine how often a given transmitter was present as a percentage when recording measured values ​​(e.g. PGS = 90 means that the transmitter was measured on average with 9 of 10 measurements).

[0011] In addition, the reference packet may contain information about the spatial orientation of the portable terminal device with which the corresponding reference packet has been registered. This means that the orientation information contains data about the direction in which the portable terminal was held or moved when calibrating the reference point. This information is particularly important in a situation where a portable end device, e.g. a device that supports the WLAN standard is held directly in front of the user's body, which may cause a shielding effect. However, even without the aforementioned shielding effect, additional information about the device's orientation can be useful due to the fact that virtually every antenna has directional characteristics. Orientation can therefore also refer to the spatial orientation of the main antenna panel of the portable terminal device.

[0012] The described data / reference packages are usually generated at least during the training or teaching phase during the operation of the radio navigation system and can be collected in various ways, such as manually generating individual points or reference packages and generating reference data as part of a mobile measurement or based on data radio navigation system planning.

[0013] As mentioned above, radio navigation using the fingerprinting method uses primarily signal strength (RSSI) of transmitters to determine the position. The signal strength recorded by the positioning device, i.e. the one used by this device for radio navigation, may fluctuate for various reasons. Different antennas for measuring WLAN signals can, for example, significantly differ in quality, in particular given that the positioning software using WLAN is to be independent of the given device and platform, so that it can be used on as many different types as possible types of end devices. These types of antenna quality differences can affect the observed signal levels used to determine location.

In addition to the aforementioned differences in antenna quality, other factors may also affect the level of radio signals used to determine the position. For example, the positioning device may be in a pocket of clothing or luggage for some time. In such cases, the radio signals are more or less attenuated by the material from which the clothing or luggage is made.

[0014] Due to the fact that based on the strength or level of the signal, conclusions can be drawn regarding the distance between the positioning device and the radio transmitter transmitting the appropriate radio signal, knowledge of the actual signal strength (i.e. without distortions due to different antenna quality or variable attenuation) can contribute to the reliable determination of the current position of the device.

[0015] The object of the present invention is therefore to immunize the radio navigation to fixed or pseudo-permanent factors affecting the strength of the signals used to determine the position.

[0016] This object is achieved by means of a calibration device of a positioning device having the features set out in claim 1 or a procedure for calibrating a positioning device by means of radio navigation according to claim 14.

[0017] According to the present invention, individual radio signals are not (exclusively) tested independently of each other, but signal patterns are generated consisting of one or more radio signals that can be compared with reference data. Generation of radio signal patterns can be based on the fact that certain features of the pattern will generally be not susceptible to the influences mentioned above (e.g. depending on the device). The calibration according to the present invention aims at correcting permanent or at least pseudo-permanent influences. In this way, the basis of calibration can be a relatively large amount of data, which in terms of time, space, frequency of radio signals or other quantities is sufficiently dispersed to take into account random deviations and / or be representative.

[0018] In accordance with the embodiments of the present invention, a position calibration device will be provided. The calibration device consists of an element comparing the received radio signal pattern with multiple radio reference patterns, an element determining the difference in signal strength, and an element determining and providing the device with a calibration value for determining the position. An element comparing the received radio signal pattern with multiple radio reference patterns has been made so as to select a subset of the selection from the multiple radio signal reference patterns based on the match criterion between the received radio signal pattern and a given radio reference pattern from among the many radio signal reference patterns. The determination of the calibration value by the element determining this value is based on the difference in signal strength.

The received radio signal pattern includes at least one transmitter name and the radio signal strength that can be received. The comparison element was further made in such a way as to compare the relative signal strengths for the various names of the transmitters within the received radio signal pattern with the respective relative signal strengths within the radio signal reference pattern, thereby determining the compatibility criterion.

[0019] Radio reference signals that are similar to the received radio signal pattern are added to the selection subset. This similarity is usually mapped quantitatively, but at least qualitatively using the compliance criterion. As a rule, it can be assumed that radio reference patterns added to the selection subset refer to positions close to the current position of the positioning device, i.e. the position where the radio signal pattern was received. Simply put, it can be assumed that the effect of differences between the received radio signal pattern and the (similar) radio signal reference pattern is that the level of the received radio signal pattern used to determine the position is determined to be invariably lower or higher compared to when the reference data was generated. For closer analysis, for example, you can often find an almost invariable difference in signal levels between two devices across the entire measurement range. In another possible scenario, it can be assumed that this difference is substantially constant for at least the period during which the positioning device is in clothing or luggage. Such pseudo-constant signal level fluctuations cannot be sufficiently taken into account with the help of a pre-set correction value, programmed permanently in the positioning device.

[0020] According to the implementing examples, the compliance criterion may be indifferent to the scaling of the received radio signal pattern and radio reference patterns. This means that systematic or temporary deviations in signal strength do not affect the compliance criterion or the effect is small, and the decision to add a given radio reference pattern to a selection subset does not depend on the absolute strength of the received radio signal pattern and / or radio reference pattern , because the calibration presented here must assume that at least the strength of the received radio signal pattern has a permanent or pseudo-permanent error.

[0021] According to further embodiments, the comparison element may be made to compare the criterion of compliance with the ACC threshold value_th. If the match criterion between the received radio signal pattern and the specified radio signal reference pattern meets the condition defined by the ACC threshold value_th, the received radio signal pattern and the specified radio signal reference pattern will be added to the selection subset as combined values ​​(e.g., as data elements collating data structures). However, if the relevant compliance criterion does not meet the condition set by the ACC threshold_th, the received radio signal pattern and the specified radio reference pattern will not be added to the selection subset. As a result of the addition of the received radio signal pattern and the specified radio reference pattern after the said condition is met to a subset of the selection as combined values, it is clear between which radio signal patterns the difference in signal strength should be determined. ACC threshold_th as a rule, it ensures that only radio reference patterns are added to the selection subset that are sufficiently similar to the received radio signal pattern. In this way, it can usually be reliably prevented sufficiently that the calibration is based on incorrect data.

[0022] According to the working examples, the comparison element may be made such that it selects such radio reference patterns for a subset of selection whose criterion for compliance with the received radio signal pattern is within a tolerance range comprising the predetermined best criterion of compliance. The tolerance range will usually be limited to one side only so that the new best compliance value is always taken into account. However, according to this implementing example, the tolerance range also includes inferior compliance criteria based on the best value so far. In this way, the radio reference reference pattern that is most compatible in the second, third, etc. order will also be added to the selection subset, which will provide more calibration data. In this way it is also possible to reliably prevent a situation in which as a result of an accident (e.g. by the noise in a given radio signal), the reference signal of the radio signal could only affect the calibration, although in the absence of accidental influence it would not have reached the best value of the compliance criterion. It should be taken into account that the best-determined match value so far can be determined continuously when comparing a received radio signal pattern with multiple radio reference patterns, or can be determined earlier. In the latter case, the absolute best value of the compliance criterion will serve as the best specific value so far.

[0023] According to an exemplary embodiment, the tolerance range may at least in one direction comprise the best compliance criterion value previously determined within the width of the tolerance range, which should be successively 30, 10 and 5% of each best compliance criterion value determined so far. Example: a tolerance band width of 5% of the best compliance criterion determined so far indicates a relatively strict selection in terms of adding radio reference patterns to a subset of the selection. The selection subset will contain more than one radio reference pattern only if the matching criterion of the best two, three, four or more radio reference patterns matches the received radio signal pattern and these patterns are in a narrow area of ​​5% best compliance value. This situation can occur, for example, when the positioning device is located at a similar distance from several radio transmitters and the propagation conditions of radio signals are generally similar (or the distance and propagation conditions of various radio signals compensate each other). In this case, it may be appropriate to include all radios with similar signal strength during calibration instead of only one radios with the highest signal strength.

[0024] Alternatively, the comparison element may be made such that it selects such radio signal reference patterns for a subset of selection whose criterion for compliance with the received radio signal pattern is in the upper or optimal quantile of the compatibility criterion for many radio reference patterns. For example, you can add one percent of all radio reference patterns with the best criteria for compliance with the received radio reference pattern to the selection subset. The selection subset can also always contain a certain number of radio reference patterns (e.g. five) if other conditions such as the ACC threshold allow_th. In practice, it may happen that the selection subset is left empty due to the threshold condition, which usually causes temporary suspension of calibration.

[0025] According to the working examples, the comparison element may be made in such a way that it selects the reference signals of the radio signals for a selection subset that will meet the following criteria:

<img file="PL2385389T3_D0001.tif" />

<img file="PL2385389T3_D0002.tif" />

and

ACC_max = ACCo-LIMTT, where ACC₀ is the value of the compliance criterion for the radio signal reference currently with the best compatibility, and ACC_th is the threshold value of the compliance criterion that determines the addition to the subset of selections. For LIMIT, for example, you can specify a value slightly greater than 1, such as 1.05 or 1.08. The LIMIT value can be treated as the width of the tolerance range given above.

[0026] According to embodiments, the received radio signal pattern may include at least one radio name that can be received, and the strength of the received radio signal. If both the transmitter name and the strength of the received radio signal are available, a similar position determination can be made based on the names of the transmitters received in the last time unit. On this basis, you can make a more accurate position determination by analyzing the strength of the received radio signals in combination with the simultaneously received transmitter names. The radio signal pattern usually includes many data elements that contain at least the transmitter name and signal strength value. In a similar manner, at least one radio reference pattern among a plurality of radio signal reference patterns may include at least one of the name of the radio transmitter included in the radio reference pattern and the strength of the radio signal included in the radio reference pattern. In this way, by comparing the strength of the received radio signal with the reference patterns of radio signals, you can, for example, associate the relative signal strengths for different transmitter names under a given radio signal pattern and the corresponding relative signal strengths under the radio signal reference pattern, for example, and draw conclusions about correspondence between the received radio signal pattern and the corresponding radio reference pattern.

[0027] According to embodiments, the element defining and making available the calibration value may include a low-pass filter that at least filters the difference in signal strength or the calibration value. Consideration of the low-pass filter option is due to the fact that differences to be leveled by calibration and are caused, for example, by different types of positioning devices or changing (slowly) ambient conditions, are constant or change rarely or slowly. In the long run, fixed or slow changing components of the difference in signal strength or calibration values ​​dominate at the low-pass filter output, while fast changes usually due to random causes occur at the low-pass filter output only in strongly suppressed form.

[0028] According to an embodiment, the low-pass filter may be a recursive filter with an input coefficient and a filter feedback coefficient. A higher value is usually determined for the filter feedback coefficient than for the filter input coefficient, so that the feedback value on the filter output has a greater effect on the output signal than on the filter input. For example, the filter feedback ratio can be 10, 100, 1000 or 10,000 times the filter input factor. If the filter feedback coefficient was specified with parameter a, the filter input coefficient can be determined, for example, depending on the filter feedback coefficient. Example: filter input coefficient = 1 / (a ​​+ 1). An example value of a = 500 means the ratio between the filter feedback coefficient and the filter input coefficient of 25,000. The value of parameter a can be determined depending on the currently set polling interval.

[0029] According to an embodiment, the low-pass filter may be made to specify a filtered difference in signal strength from a plurality of differences in the strength of individual signals. Many differences in the strength of individual signals may correspond to differences in signal strength related to the radio signal reference pattern among the many radio signal reference patterns to radio transmitters included in the radio signal reference pattern. In addition, many differences in the strength of individual signals can serve as input values ​​for a low-pass filter. Therefore, differences in the strength of individual signals can be used further directly, because any systematic deviations will probably affect any differences in the strength of individual signals anyway.

[0030] One aspect of the present technical invention relates to a device for determining position by means of radio navigation comprising the previously described calibration device and the radio signal receiving element. The radio receiving device has been made in such a way as to receive the calibration value generated by the calibration device and to scale the radio signals using the generated calibration value, whereby the scaled radio signal data transmitted by the radio receiving device are generally consistent with the signal strength with the data reference signal with which the radio signal data is compared (by means of subsequent functional units of the positioning device). In this way, the positioning device can calibrate either continuously or at regular intervals. The ability to (self) calibration can provide reliable positioning especially in situations where the positioning device is in low-range zones with a small number of radio transmitters. In such zones, determining the position of radio signals from radio transmitters that can be received is relatively important.

[0031] According to an embodiment, the method of functioning of the positioning device is based on the principle of fingerprinting. It allows for relatively accurate position determination, especially when, in addition to the names of the radio transmitters that can be received by the positioning device, you can obtain relatively accurate data on the strength of radio signals transmitted by the radio transmitters.

[0032] The present technical invention also relates to the procedure for calibrating the position determination device by means of radio navigation, which consists of the following stages:

Comparing the received radio signal pattern with multiple radio reference patterns;

Adding radio signal reference patterns from a plurality of radio signal reference patterns to a subset of the selection by means of a match criterion between the received radio signal pattern and the corresponding radio signal reference pattern from among the many radio signal reference patterns;

Determining the difference in signal strength between the received radio signal pattern and the corresponding radio reference signal pattern from a selection subset; and Determining the signal strength calibration value and making this value available for use by the positioning device.

The received radio signal pattern includes at least one name of the received transmitter and the strength of the received radio signal. When comparing a received radio signal pattern with multiple radio reference patterns, the relative strengths of the radio signals for different names of radio transmitters are associated with each other within the received radio signal pattern with the appropriate strength within the reference pattern, which allows a match criterion to be determined.

[0033] The present technical invention also relates to a computer program enabling the implementation of said procedure if the computer program runs on a processor or microcontroller.

[0034] For both the calibration procedure and the computer program, a more detailed specification can be made by means of the aforementioned technical properties regarding the calibration instrument.

[0035] Embodiments of the present invention are explained in detail below with reference to the respective figures.

Fig. 1 Schematic description explaining how the radio navigation system functions

Fig. 2 Examples of signal strengths depending on the time when the positioning device is in the current position

Fig. 3 Graphical description of the measured radio signal pattern and similar radio reference pattern

Fig. 4 Block diagram with an overview of the device components for determining the calibration-related position according to the technical invention presented

Fig. 5 Block diagram of an embodiment of the present technical invention

Fig. 6 Block diagram of another embodiment of a calibration device in accordance with the present technical invention

Fig. 7 Top view of the geographical area in which position determination can be carried out

Fig. 8 Block diagram of a recursive low-pass filter, and

Fig. 9 Block diagram of parts of a calibration device according to an exemplary embodiment

Fig. 10 Flowchart of a calibration procedure according to an embodiment of the present technical invention [0036] Fig. 1 shows the basic principle of operation of a radio navigation system. The position determination device 10 is currently in the current position to be determined. The positioning device 10 is within the range of four radio transmitters 16, 17, 18 and 19, enabling the device to determine the position of 10 radio signals from radio transmitters 16-19. The distance between the positioning device 10 and 16-19 radios is d₁, d₂, d₃ or d₄. However, these distances are not previously known to the positioning device.

[0037] The possibility of approximate position determination results from the fact that the positioning device 10 is within the range of 16-19 radio transmitters. For this purpose, each 16-19 radio transmitter marks the transmitted radio signals with a separate transmitter name. In order to determine the position more accurately, one can use the phenomenon that the radio signals weaken depending on the distance. Based on the strength or level of the signal in the current position, the distance between the respective radio transmitter and the current position in which the positioning device 10 is located can be estimated. This information enables the position to be determined, e.g. by interpolation.

[0038] One possible implementation of the radio navigation system is the fingerprinting method. The fingerprinting principle means that radio signals received in the current position from 16-19 radio transmitters are compared with many previously registered reference points. For further processing, a reference point will be selected whose selected properties of the received radio signals (radio transmitter identification and signal strength) are most similar. It can be assumed that the position determination device 10 is close to the position at which the reference point was registered and which is therefore known.

[0039] Fig. 2 shows an example of the time course of the actually observed signal strength 22, which relates to the radio signal of the radio transmitter and in the manner in which it was determined by the given position determination device 10 in the current position. Signal strength is shown on the ordinate of the graph in Figure 2 and is designated RSSI (Received Signal Strength Indicator). Indeed, the observed signal strength 22 is essentially constant and deviates only slightly from the long-term average.

[0040] The dashed line in Fig. 2 further shows the time course of the expected signal strength 24, determined for example in the training or teaching phase of the radio navigation system. The positioning device used in the training phase may differ from the device used in the use phase. Therefore, the expected signal strength 24 differs from the actual observed signal strength 22. However, the deltaRSSI deviation is essentially constant throughout. Without taking additional action, the position determination device 10 cannot determine what part of the deltaRSSI deviation falls between the radio 16 and the position determination device 10, and what part falls on the systematic deviation, e.g. due to the use of antennas of different quality in phase training as well as in the later stages of use.

[0041] Fig. 3 shows the signal strengths 31, 32, 33 and 34, which in the current position have actually been observed by the positioning device 10 depending on the index and information about the radio transmitter. Signal strengths depicted depending on the particular radio transmitter or the name provided by the radio transmitter can serve as an example of the characteristics of the radio signal pattern. FIG. 3 it also shows a similar signal reference pattern resulting in a similar principle from reference signal strengths 36, 37, 38 and 39. A similar signal reference pattern is shown with a dashed line. The similarity between the received radio signal pattern and a similar signal reference pattern results in the example shown in Fig. 3 from the fact that the signal strength difference is 6 dB, respectively. As a criterion for the compatibility of radio transmitters, for example, one can cite the dispersion of differences in signal strength by means of the index i. Due to the fact that in practical applications of the positioning device there will usually be a large number of reference patterns of radio signals, the purpose of calibration is to make a selection from a set of patterns radio signal references that are similar to the received radio signal pattern within the meaning of the compliance criterion. This choice should be indifferent to the absolute forces of the received radio signal pattern, which means that it usually does not matter whether the deviation shown in Fig. 3 has a fixed value of 6 or 8 dB. Usually, the only thing is that the deviation should be essentially the same for all radio transmitters and, i.e., have a small spread.

[0042] Fig. 4 shows the possibility of using calibration in a position determination device 10. The finger positioning device 10 typically includes a measurement value recording system 42, which inter alia acts as a radio signal receiver. This enables the appropriate processing of received radio signals (amplification, demodulation, etc.). The measured value recording system 42 also determines the strength of the received radio signals. The 42 measured value recording system provides so-called measurement packs or 'measurement packs' (MPs) which are then used by the WLAN 44 locating module. The WLAN 44 locating module usually compares the received transmitter names with the database and determines the position of the measuring device based on the strength of the signals provided by the measured value recording system 42 position. The block diagram in Fig. 4 shows a calibration device built into localization module 44. In this way, the WLAN locating module 44 provides the measuring value recording system 42 with a calibration offset value. The measured value recording system 42 uses the calibration offset value to properly correct the signal strength values ​​specified by it, which, as a rule, has a positive effect on the operation of the measured value recording system 42.

[0043] Fig. 5 is a block diagram of a calibration device according to the present invention. For example, the calibration device receives from the measured value recording system 42 measuring package 50. Alternatively, the calibration device can be made in such a way as to determine the measurement package 50 itself. The calibration device also has access to a mass memory or a database containing reference packages 54 (RP) . A received measurement packet 50 reflecting a recently received radio signal pattern along with reference packets 54 are provided to the comparison element 51. The comparison element 51 is usually responsible for comparing multiple reference packets 54 with the received measurement packet 50, with differences between the reference packets 54 and the received measuring packet 50 resulting from systematic, constant and / or pseudo-permanent deviations usually being ignored by the comparison element 51 (if it is possible). As output, the comparison device 51 provides a selection of reference packets 55 including packets that, regardless of said systematic, constant and / or pseudo-permanent deviations, are similar to the received radio signal pattern in the received measuring packet 50. This kind of similarity can usually be interpreted in such a way that the reference signals of the radio signals contained in the selected reference packets of the selection of reference packets 55 have been registered in positions close to the current position to which the received radio signal pattern of the received measuring packet 50 relates.

[0044] Upon completion of the selection of reference packets 55, it is provided to the element determining the difference in signal strength 56 ("matching"). The element determining the difference in signal strength 56 also contains an input for the current measuring packet 50. The element determining the difference in signal strength 56 usually determines the difference in signal strength for each reference packet in the selection of reference packets 55. Specific differences in signal strength ("deltaRSSI values") are recorded in the data structure or database 57, from where they are supplied to the historical weight filter 58 ("history weight filter"). In this way, the deviations between the reference packets and the received measurement packet are dominant, which from a statistical point of view occur on average in a large number of pairs of reference packets 54 and 50 measuring packets. The historical data filter 58 provides a calibration calibration value 59 ("calibration offset") that is feed backed into the measurement value recording system 42 (Fig. 4).

[0045] Fig. 6 is a slightly more detailed block diagram of the calibration device according to an embodiment of the present invention. The received radio signal pattern is delivered to the element comparing the radio signal patterns 61.

[0046] Another input value of the radio signal pattern comparison element 61 is a given radio signal reference pattern among a plurality of radio signal reference patterns 64. It should be remembered that a particular received radio signal pattern is usually compared with many or even all of the radio signal reference patterns 64 using item 61. To limit the computational power and time required to compare radio signal patterns, a reasonable pre-selection can be made from a plurality of reference patterns of radio signals 64, for example based on recently determined positions, since they are probably near the current position. The element comparing the radio signal patterns 61 provides the appropriate ACC compliance criterion_and for reference pair (received radio signal pattern and radio signal reference pattern). Specific ACC compliance criterion_and is first compared using function block 62 with the ACC threshold_th. If specified ACC compliance criterion_and is greater than the absolute ACC threshold_th, there is not sufficient agreement between the received radio signal pattern and the radio reference pattern, and the reference pair will be rejected. However, if the compliance criterion meets the condition ACCi &lt;ACCTh, the ACCi compliance criterion is passed to the block of selection function 63, which will determine the best value of the compliance criterion

ACC_and or a set of best compliance criteria values. In the situation presented in Fig. 6, low values ​​of the ACC compliance criterion_and they correspond to good agreement between the received radio signal pattern and the corresponding radio signal reference pattern, while the high values ​​of the ACC compliance criterion_and reflect inferior compliance. Ultimately, this is a matter related to the definition of the compliance criterion and has no significant impact on the present invention. The abbreviation ACC used to define the compliance criterion comes from the English word "accuracy". Depending on the implementation and configuration, the selection function block 63 provides an index or multiple indexes relating to the radio signal reference pattern or radio signal reference patterns that are most compatible with the received radio signal pattern. Index or indexes and are passed to the database query 65, which uses them to send queries to the database with 64 reference radio patterns. The database 64 then returns the corresponding radio signal reference patterns, and the database query element 65 inserts them into the data structure or another database 66 that contains a selection of radio signal reference patterns.

[0047] Fig. 6 shows a continuous selection of radio signal reference patterns, within which the radio signal reference pattern with the currently best compatibility criterion can be constantly changed. Alternatively, it can also be assumed that for each measurement packet (MP) determined by the positioning device, the compliance criteria of all (or at least some) radio reference patterns in the database 64 will be determined once. The radio signal reference patterns are then analyzed according to compliance criteria, which allows the most compatible radio signal reference pattern or the most compatible radio signal reference patterns to be determined.

[0048] Both the received radio signal pattern and the radio signal reference patterns included in the selection of the reference signals of the radio signals 66 are used as input values ​​by the element determining the difference in signal strength 67. As already mentioned in the context of Fig. 5, one difference is determined. signal strength for each reference pair consisting of the received radio signal pattern and the selection reference radio signal pattern 66. In this way, the element determining the difference in signal strength 67 provides a plurality of differences in signal strength (deltaRSSI values). The differences in signal strength supplied are delivered to the low-pass filter in the order in which they are calculated. A low pass filter 68 defines a calibration value that roughly corresponds to the constant deviation found in a large number of comparative pairs between the received radio signal pattern and selected radio reference patterns. The calibration value is then recorded by the element providing the calibration value 69, where it is made available to the receiving module of the positioning device or where the positioning device has access to it.

[0049] The ACC compliance criterion can be determined as described in patent application DE 10 2008 036 681 A1. Radio signals or radio transmitters assigned to radio signals can be separated or filtered to the first number N_eq radio transmitters whose previously registered names in the reference position are identical to the names provided in the current position, and up to the second number N_neqradio transmitters whose previously registered names in the reference position differ from the names provided in the position, i.e. radios whose names are delivered only in the current position and have not been registered in the reference position, or whose names were previously registered only in the reference position and were not provided in current position. An additional step may be present to make the second number N_neq radio transmitters select the number N_nh ("Not heard") radio transmitters too rarely received in the current position, i.e. radio transmitters whose previously registered properties exist in the reference position, but their properties are not present in the current position. The greater the number N_nh radio transmitters too rarely received at the current position, the more likely the current position does not match the reference position. Another stage may be envisaged, at which of the second number N_neq radio transmitters the number N will be selected_htm ("Heard too much") radio transmitters too often picked up at the current position for which there are no previously registered electromagnetic properties at the reference position, but their electromagnetic properties are delivered at the current position. The greater the number N_htmradio transmitters received too often at the current position, the more likely the current position does not match the reference position. Second number N_neq radio transmitters result from the number N_nh radio transmitters too rarely received in the current position and the number N_htm radio transmitters too often received in the current position according to formula N_neq = (N_nh + N_htm).

[0050] On the basis of the provided properties of radio signals in the third stage, a compatibility criterion or ACC distance value for the current position is determined, while determining the compatibility criterion, both the properties of the first number N are taken into account_eq as well as the second number N_neq radio transmitters that affect the compliance criterion differently. According to the implementing examples, the properties of the first number of Neq radios are more important than the properties of the second number of Nneq radios, as discussed in detail below.

[0051] Determining or providing the properties of radio signals is the task of a mobile end device or client, e.g., a palmtop that supports the WLAN or Bluetooth standard, or a mobile phone. For this purpose, the customer is equipped with an element that determines or provides the properties of radio signals of fixed position radios, which properties are usually characterized by the name of the fixed position radio and its electromagnetic signal characteristics, such as receiving field strength, receiving spectrum or received signal ratio to noise.

[0052] The name or identification feature of the fixed position radio can be, for example, the MAC address (MAC = Media Access Control), base station name or cell name.

[0054] The properties of radio signals can be understood to be the MP (i) measuring packages described above. Specific or supplied MP (i) properties are provided to the radio splitter 34 or associated radio transmitters for the first number N_eq and the second number N_neq radionadajników. First number N_eq Radio transmitters includes radio transmitters whose previously registered names in a given reference position are identical to the names of transmitters specified in their current position. Second number N_neq = (N_nh + N_htm) radios include radios whose names are provided only in this position and which have not previously been registered in the reference position, or whose names have previously been registered only in the reference position and are not supplied in this position. Radio signals are divided into at least two groups. The first group includes the properties of radio signals of the first number N_eq radios, while the second group includes the properties of radio signals of the second number N_neq radionadajników. As described earlier, the second group can be further divided into a group of properties of radio signals received too rarely received radios in the current position and into a group of properties of too often received radios in this position. The properties of the first number of Neq radios and the properties of the second number of Nneq radios can affect the compliance criterion differently, i.e. they can be weighed differently.

[0054] At each place or position, signals from multiple base stations or radio beacons are delivered with different signal strengths along with corresponding names if they can be received. For this type of WLAN, an electronic fingerprint includes a list of unique MAC addresses for each device or radio transmitter together with the corresponding strength of the received signals, thus determining the current position. It does not matter where the WLAN radios are located.

[0055] Next, differences are created between previously recorded electromagnetic properties at the reference position and the electromagnetic properties of the first number N_eq radio transmitters, delivered in the current position. For example, differences are created between the RSSI values ​​of radio transmitters whose previously registered names in the reference position are identical to the names of the transmitters provided in the current position. From these differential RSSI values ​​ARSSIl-ARSSIN_eq the sum of ΣΔΚββ ^ is created. Neq is the first number of radio transmitters found in both the measurement and reference packages. The ΔRSSI function calculates the distance between two signal strength values. For example, you can select the Euclidean distance between measured values ​​in dB as a function of distance. In this context, distance does not mean a space gap, but a mathematical deviation. After adding the sum

ΣΔRSSI_n is weighted by the weighting factor EQW, i.e. EQW ^ ARSSI_n. At the same time, the EQW factor defines a weight between 0 and 1, which determines how strongly the distance between measured values ​​or signal strength values ​​ΣΔRSSIn is to be assessed compared to too often or too rarely received radios in the current position.

[0056] If the calculation of the compliance criterion were to be stopped at this point, it would be possible to select as reference candidates that are in fact less suited to the current position. Example: suppose for the first reference point N_eq = 1 compared to the current position, i.e. the match only occurs for one radio name between the reference measurement packet and the current measurement packet. If the distance between the respective RSSI values ​​of the compatible measurement packets is accidentally 2.5 dB, the result is ΣΔRSSIl / N_eq = 2.5 dB. Suppose further that for the next reference point N_eq = 3 compared to the current position, i.e. there is a match between the three radio names between the reference measurement packet and the current measurement packet. If in this situation the distance between the respective RSSI values ​​is, for example, 2 dB, 3 dB and 4 dB, the result is ΣΔRSSI_n / N_eq = 3 dB. Consequently, the second reference point would be rated worse than the first, which would lead to estimation errors. The previously described formula avoids or at least reduces such errors.

[0057] For each radio transmitter received too seldom, a function or bullish value ("malus") M can be defined_{NH; m}() (m = 1, ..., N_nh). This means that for each occurring in the reference values ​​but not in the current measured values ​​of the transmitter, an increase value M can be defined_{nh, m}() (m = 1, ..., N_nh). It may depend on the extent to which the corresponding transmitter received too seldom was reliably received in the reference position in the past. In the case of good reception so far too seldom received transmitter, i.e. a large RSSI value, the bullish value will be high. Bullish value of M_{nh, m}() (m = 1, ..., N_nh) can therefore be directly proportional to the RSSI reference value too rarely received at the current transmitter position. In addition, the bullish function M_{nh, m}() (m = 1, ..., N_nh) may be associated with the PGS value of the corresponding, too infrequently received radio transmitter. For example, a low PGS value in a reference data can only lead to a small value of the corresponding bullish function M_{nh, m}(). This relationship can, for example, be calculated using the following formula:

M_niwii (PGS) = FixMalus + DynamicMalus, where DynamicMalus = FixMalus * PGS / 100. According to the implementation examples, the function M_{nh, m}() (m = 1, ..., N_nh) for an upward value of a transmitter received too seldom, depends on the property related to the receiving field strength that was previously registered at the reference point and on the models, e.g. the environment, the quality of the measured values, etc. The increase values ​​N_nh M_{nh, m}() (m = 1, ..., N_nh) radio transmitters too rarely received in the current position will be further processed to determine the first sum ΣΜηή ^ Ο of the N_nh too rarely received radio transmitters.

[0058] Properties of radio signals from the number N_htm too often, radios received in the current position are assigned to radios that do not have previously registered electromagnetic properties in the reference position, but their electromagnetic properties are supplied in the current position. Any radio transmitter received in the current position, which is too often, can be assigned a ramping function M_{htm, r}() (r = 1, ..., N_htm) or a bullish value. This means that for each not occurring in the reference values, but occurring in the current measured values ​​of the radio transmitter, an increase value M can be defined_{htm, r}() (r = 1, ..., Nhtm). Also in this case, the function of the bullish value Mhtm, r () (r = 1, ..., Nhtm) may depend on the current RSSI measured value of the radio transmitter and on models, e.g. the environment, quality of measured values, age of reference data, etc. Too often the radio transmitter received in the current position can be assigned the upward function M_{htm, r}() (r = 1, ..., N_htm) depending on the property associated with the receiving field strength of its radio signal, for example, RSSI values. Bullish value of M_{htm, r}() (r = 1, ..., N_htm) is therefore usually directly proportional to the RSSI reference value too often received at the current transmitter position. In addition, the increase function Mhtm, r () (r = 1, ..., Nhtm) can be associated with the PGS value of a corresponding, too often received radio transmitter. For example, a low PGS value in a reference data can only lead to a small value of the corresponding bullish function M_{htm, r}() (r = 1, ..., N_hm). Bullish values ​​N_htm too often, received radios will be added to the second ΣMht_m,_r().

[0059] According to the implementing examples, the first sum ΣM_nh_m() bullish values ​​of too rarely received radios will be added to the second sum of htMhtιτι,_r() radio receivers received too often and will be weighted by a weighting factor (1 - EQW), i.e. (1 - EQW) &lt;ΣM_nh_m() + ΣMht_m,_r() ).

[0060] They will then be added together and standardized using (N_eq + N_nh + Nht_m): weighted sum of EQW0ARSSI_n differences between previously recorded electromagnetic properties in the reference position and the electromagnetic properties of the first number ^Neq radio transmitters, delivered in current position, and weighted sum (1 - EQW). (ΣM_nh_m() + ΣMht_m,_r()) bullish values ​​to calculate the ACC distance value between the current position and a given reference position. The ACC distance value can therefore be calculated using the following formula:

<img file="PL2385389T3_D0003.tif" />

[0061] If the ACC distance value is determined according to G1. (1), the correspondence between the current position and a given reference position will be greater the smaller the ACC distance value is. This means that compliance will be greater the lower the sum will be

ΣΔRSSI_n differences and the smaller the ZM sums will be_nh, m (), ΣΜ ^, γΟ increase values.

[0062] According to other implementing examples, the compliance criterion can also be inverse to the ACC distance value or can be calculated from (1-ACC) if the ACC value cannot be greater than 1. This means that the smaller the ACC distance is, the greater the compliance criterion. Of course, you can also assume other calculation instructions, where the properties of the first number N_eq radio transmitters and second number properties ^Nneq ^{= (N}nh ^{+ N}htm⁾ Radio transmitters affect the compliance criterion in different ways.

[0063] According to the method described for calculating the ACC distance value, each transmitter too often or too rarely received increases the ACC distance. The processing of different transmitters in the fingerprint and current measured values ​​strongly affects accuracy: a transmitter not present in the stored reference fingerprint that appears in the current measurement is a clear indication that the fingerprint is inadequate.

[0064] Fig. 7 is a plan view of a geographical area 70, for example a city district or market hall with market stands and passages between them. Position determination device 10 is in the current position 76. For many positions in geographical area 70 reference records have been registered, which are shown in figure 7 in the form of a circle or a cross. The reference positions 79 represented in the form of a cross are too far from the current position 76 of the positioning device 10, which results in incompatibility of the radio transmitters that can be received in these positions (or the compliance is low). At reference positions 78 represented as a circle, there is at least one substantial agreement between the radio signal pattern received at the current position 76 and the radio reference pattern marked for a given reference position. This fundamental compatibility may result from sufficient compatibility of the radio transmitters, which can be received in both positions. FIG. 7 also presents the criterion of correspondence between the received radio signal pattern at the current position 76 and the reference patterns of the radio signals at the given reference positions. A small circle at a given reference position means that there is only little agreement. However, a large circle means high compatibility.

[0065] Reference positions 71, 72, 73, 74 and 75 near the current position 76 correspond to a relatively good correspondence between the received radio signal pattern and the corresponding radio signal reference patterns. Reference position 71 is the position with the best compatibility. Reference positions 72-75 have sufficient agreement between the received radio signal pattern and the corresponding radio reference patterns, which means that they can also be used for calibration purposes. Therefore, radio reference patterns corresponding to reference positions 71-75 will be included in the selection of radio reference patterns 57 or 66 (Figures 5 and 6). Even if the strength of the received radio signal pattern at the current position 76 would be significantly different in absolute terms from the strength of the signals specified for the reference position 71-75 due to a failed or poor calibration, the comparison element 51, 61 will cause the reference positions found to be used for calibration near the current position 76.

[0066] Fig. 8 is a block diagram of an embodiment of a low-pass filter that can be used, for example, in a historical data filter 58 or a low-pass filter 68. The filter shown in Fig. 8 is a recursive filter, which pre-filter the value at the filter input by a factor input filter 81. The input coefficient of the filter 81 is here expressed depending on the parameter a as 1 / (1 + a). The value at the filter input is multiplied by the filter input coefficient 81 and the result is provided to the summing amplifier 82. The summing amplifier 82 has an additional input with which the earlier value at the filter output is provided. The previous value at the output of the filter is taken at the output of the summing amplifier 82, supplied to delay element 83, and then multiplied by the filter feedback factor 84, which in the case shown in Fig. 8 corresponds to the parameter a. The state at the output of the filter at time k can thus be expressed as follows:

y [k] = (l / (l + a)) x [k] + ay [kl}.

[0067] For parameter a, a relatively large value, for example 500, should generally be specified. The value of parameter a may depend on the currently set probing interval ("polling interval").

[0043] Fig. 9 is a schematic diagram of a method of providing values ​​at a filter input to a low-pass filter 68. Differences in signal strength determined by the elements determining the difference in signal strength 56, 67 are buffered in data structure 96. Data structure 96 can be organized in such a way that the difference in signal strength for the received radio signal pattern relative to multiple radio reference patterns is recorded in vectors of different length. The vectors may have different lengths because, depending on the received radio signal pattern, there is practically enough radio reference patterns in the selection subset. The vectors in data structure 96 can be marked depending on when they are added to data structure 96 so that they can be read in this order by sequencer 97. Sequencer 97 reads the individual signal strength values ​​of the currently read vector and transmits them to the lowpass filter 68. After reading the vector belonging to a specific radio signal pattern, this vector can be removed from the data structure 96, which will free up memory space for newly supplied differences in signal strength.

[0069] The designation deltaRSSI ij denotes the difference in signal strength between the received radio signal pattern and and the reference radio signal pattern j, wherein j corresponds to the numbering in the selection set of the reference radio signal patterns for the received radio signal pattern i.

[0070] Fig. 10 is a block diagram of a calibration procedure according to an embodiment of the present technical invention. After starting the procedure in field 101, field 102 receives the current radio signal pattern. The calibration procedure then performs in field 103 a comparison between the received radio signal pattern and multiple radio reference patterns. Based on the comparison, a radio reference reference pattern or multiple radio reference patterns are added to the selection subset. To this end, the compatibility criterion between the received radio signal pattern and the individual radio reference patterns is analyzed.

[0071] For each of the radio signal reference patterns contained in the selection subset, the difference in signal strength between the received radio signal pattern and the individual radio signal reference patterns is determined (box 105). In field 106 the value of the signal strength calibration is determined on the basis of specific differences in signal strength, whereby, as a rule, averaging of many differences in signal strength is performed to exclude accidental fluctuations of the calibration value if possible. In field 107, the calibration procedure provides the calibration value used by the device for determining the position. The calibration value provided is usually used by the receiving element of the device to determine the position. After successful calibration, the receiving component may determine the absolute values ​​of the strengths of the received radio signal patterns or received radio signals with sufficient accuracy for position determination. The procedure terminates in field 108, but may be periodically repeated. For example, it can be performed once per unit of time, e.g. every 10, 30 or 60 seconds. The procedure can also be initiated as a result of special circumstances, e.g. after receiving a new radio signal pattern.

[0072] Although some aspects have been described in the context of the instrument, these aspects are also a description of the relevant procedure, and the instrument block or subassembly should also be seen as an appropriate stage of the procedure or a feature of the stage of the procedure. Similarly, aspects described in connection with a stage of a procedure or as a stage of a procedure are also a description of the respective block, detail or feature of a given instrument. Some or all of the steps in the procedure may be performed with or using a hardware device, such as a microprocessor, programmable computer, or electronic system. For some implementations, such an apparatus may perform some of the most important stages of the procedure or many of the most important stages of the procedure.

[0073] Depending on the specific implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be carried out using a digital medium, e.g. floppy disk, DVD, Blu-ray or CD, ROM, PROM, EPROM, EEPROM or FLASH, hard disk or other magnetic or optical memory on which electronically readable control signals are stored that can interact or interact with a programmable computer system in a manner that allows the performance of a given procedure. Therefore, the digital media can be computer readable.

[0074] Therefore, some embodiments in accordance with the invention include a data carrier with electronically readable control signals capable of interacting with a programmable computer system in a manner that allows one of the procedures set out to be performed.

[0075] Embodiments of the present invention may generally be implemented in the form of a computer program comprising a program code, the program code enabling one of the procedures to be performed if the computer program is running on the computer.

[0076] The program code may also be saved on a computer readable medium.

[0077] Other implementing examples include a computer program enabling one of the procedures outlined to be performed, wherein the computer program is recorded on a computer readable medium.

[0078] In other words, an implementing example of the procedure covered by the invention is a computer program containing a program code for performing the presented procedure if the computer program is running on the computer.

[0079] Another implementing example of the procedures encompassed by the invention is a data carrier (or digital carrier or computer readable medium) on which a computer program is located which allows the procedures outlined.

[0080] Therefore, another embodiment of the procedure covered by the invention is a data stream or a sequence of signals the representation of which is a computer program enabling the implementation of the described procedures. The data stream or signal sequence may be configured to be transferred via a data communication connection, for example via the Internet.

[0081] Another embodiment includes a processing element, for example a computer or programmable logic module, configured or adapted to perform one of the procedures outlined.

[0082] Another implementing example includes a computer on which a computer program has been installed that enables one of the procedures outlined.

[0083] Another embodiment in accordance with the invention includes a device or system enabling a computer program to be transferred to a recipient to perform at least one described procedure. The transfer can be electronic or optical. The recipient can be a computer, a portable device, a memory device or similar device. The device or system may include a data server for transferring the computer program to the recipient.

[0084] For some embodiments, a programmable logic module (e.g., programmable FPGA gate matrix) may be used to perform some or all of the functions of the procedures outlined. For some implementation examples, the programmable gate matrix may work with a microprocessor to perform one of the procedures outlined. For some implementing examples, the procedures are generally performed by any hardware device. It can be universal equipment, e.g. a computer processor (CPU), or equipment adapted to a given procedure, e.g. an ASIC.

[0085] The above-described embodiments merely illustrate the principles of the illustrated invention. We assume that modifications and variations of the described systems and details are understood by other professionals. Therefore, the invention is to be limited only by the scope of protection of the following claims, and not to the specific details provided on the basis of the description and explanation of the embodiments.

FraunhoferGesellschaft zur Forderung der Angewandten Forschung eV; Germany Representative:

EP 2 385 389 B1 Z-10728