Method as well as device for timeslot-wise detection of at least one radio signal

Abstract

A method of timeslot-wise detection of at least one radio signal in a cellular radio network. A radio signal is received via at least one first radio antenna and at least one second radio antenna. The radio signal received by the respective radio antennas is forwarded to at least one first radio receiver assigned to the first radio antenna and to at least one second radio receiver assigned to the second radio antenna. The radio signal forwarded is evaluated. The radio receivers are synchronized with a preconfigured frame structure. At least one identical time slot is selected out of the frame structure Timing information of the selected time slot is provided from the first radio receiver to the second radio receiver, from the second radio receiver to the first radio receiver and/or from the respective radio receiver to a central unit for calculating a time difference of arrival. Further, a device for timeslot-wise detection is described.

Claims

1. A method of timeslot-wise detection of at least one radio signal in a cellular radio network, wherein a radio signal is received via at least one first radio antenna and at least one second radio antenna, wherein the radio signal received by the respective radio antennas is forwarded to at least one first radio receiver assigned to the first radio antenna and to at least one second radio receiver assigned to the second radio antenna, and wherein the radio signal forwarded is evaluated by the following steps: synchronizing the first radio receiver with a preconfigured frame structure and synchronizing the second radio receiver with a preconfigured frame structure; selecting at least one identical time slot out of the frame structure at the first radio receiver and the second radio receiver; and providing timing information of the selected time slot from the first radio receiver to the second radio receiver, from the second radio receiver to the first radio receiver and/or from the respective radio receiver to a central unit for calculating a time difference of arrival.

2. The method according to claim 1, wherein the radio receivers are synchronized with a system clock and/or a timing source of the cellular radio network.

3. The method according to claim 1, wherein the preconfigured frame structure corresponds to a communication standard to be investigated that is used by the cellular radio network.

4. The method according to claim 1, wherein at least one interference is detected in the at least one radio signal such that an interfering emitter is identified.

5. The method according to claim 4, wherein the interfering emitter detected is displayed graphically and/or wherein the interfering emitter detected is written to a flag.

6. The method according to claim 1, wherein the time difference of arrival calculated is post-processed.

7. The method according claim 1, wherein the location of the emitter identified by direction finding is graphically displayed and/or wherein a flag for a correct or faulty signal is set.

8. A device for timeslot-wise detection of at least one radio signal in a cellular radio network, comprising at least one first radio antenna configured to receive the radio signal, at least one second radio antenna configured to receive the radio signal, at least one first radio receiver configured to process the radio signal, at least one second radio receiver configured to process the radio signal and at least one evaluation unit, wherein the evaluation unit is configured to evaluate the at least one radio signal, wherein the evaluation unit is configured to synchronize the respective radio receivers with a preconfigured frame structure and to select at least one identical time slot out of the frame structure at the respective radio receivers, and wherein the evaluation unit is configured to provide timing information of the selected time slot from the first radio receiver to the second radio receiver, from the second radio receiver to the first radio receiver and/or from the respective radio receiver to a central unit for calculating a time difference of arrival.

9. The device according to claim 8, wherein one evaluation unit is provided for each radio receiver so that each radio receiver is assigned to its own evaluation unit.

10. The device according to claim 9, wherein the at least two evaluation units are interconnected with each other.

11. The device according to claim 8, wherein the respective radio antenna and the corresponding radio receiver are connected with each other so that the radio signal received by the respective radio antenna is forwarded to the corresponding radio receiver.

12. The device according to claim 8, wherein the radio receivers are synchronized with a system clock and/or a timing source of the cellular radio network.

13. The device according to claim 8, wherein the preconfigured frame structure corresponds to a communication standard to be investigated that is used by the cellular radio network.

14. The device according to claim 8, wherein a post-processor is provided that is connected to the evaluation unit, wherein the post-processor is configured to post-process the time difference of arrival calculated.

15. The device according to claim 14, wherein the post-processor is configured to set a flag for a correct or faulty signal is set.

16. The device according to claim 8, wherein a display is provided with which the evaluation unit is connected.

17. The device according to claim 16, wherein the evaluation unit and the display are configured to graphically display the identified location of the emitter on the display.

18. The device according to claim 8, wherein the evaluation unit is configured to detect at least one interference in the at least one radio signal in order to identify an interfering emitter.

19. The device according to claim 18, wherein the evaluation unit and the display are configured to graphically display the interfering emitter detected on the display and/or wherein the evaluation unit and the display are configured to write the interfering emitter detected to a flag.

Description

DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 shows a schematic overview of one representative embodiment of a device according to the present disclosure;

(3) FIG. 2 shows a flow-chart representing one embodiment of one representative embodiment of a method according to the present disclosure;

(4) FIG. 3 shows a schematic illustration of a diagram on the display of the device according to FIG. 1 when the method shown in FIG. 2 is performed;

(5) FIG. 4 shows a schematic illustration of a spectrum received on the display of the device according to FIG. 1, wherein the spectrum comprises downlink signals and uplink signals; and

(6) FIG. 5 shows the spectrum received from FIG. 4 when a gated trigger is applied.

DETAILED DESCRIPTION

(7) The detailed description set forth below in connection with the appended drawings, where like numerals reference like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

(8) In FIG. 1, a device 10 for timeslot-wise detection of at least one radio signal in a cellular radio network is schematically shown. In some embodiments, the cellular radio network is based on time slots such as a time domain cellular radio network, for instance a long term evolution (LTE) network.

(9) The device 10 comprises a housing 12 that encompasses a first radio receiver 14 which is connected to a first radio antenna 16. Moreover, the housing 12 encompasses a second radio receiver 18 which is connected to a second radio antenna 20. Via the radio antennas 16, 20, the device 10 is enabled to receive at least one radio signal at two separate positions simultaneously, for example a radio signal assigned to the cellular radio network. Hence, the same radio signal is received twice, namely by the two separately formed radio antennas 16, 20.

(10) The radio signal received by the respective radio sensor 16, 20 is forwarded to the corresponding radio receiver 14, 18 for measuring or rather processing purposes as will be described later with respect to FIG. 2. Further, the radio receivers 14 are connected to at least one (central) evaluation unit 22 that is also encompassed in the housing 12.

(11) In the shown embodiment, a single evaluation unit 22 is provided. In some embodiments, the evaluation unit 22 may correspond to a software module that runs on a processor, for example. Alternatively, two or more evaluation units 22 are provided wherein the evaluation units 22 are unambiguously assigned to corresponding radio receivers 14, 18. Hence, one evaluation unit 22 is provided per radio receiver 14, 18.

(12) Further, the at least one evaluation unit 22 is connected with a post-processor 24 that is also located within the housing 12 wherein the post-processor 24 is configured to post-process the output of the at least one evaluation unit 22.

(13) In addition, the device 10 comprises a display 26 which is connected with at least one of the evaluation unit 22 and the post-processor 24. Accordingly, information forwarded to the display 26 via the evaluation unit 22 and/or the post-processor 24 is displayed on the display 26 so that a user of the device 10 is informed appropriately.

(14) The device 10 may further comprise a central unit 28 that may be configured to communicate with the at least one evaluation unit 22. The central unit 28 may also be encompassed in the housing 12. Alternatively, the central unit 28 is located separately as exemplarily shown in FIG. 1. Furthermore, the central unit 28 may be established by a sub-unit of the at least one evaluation unit 26.

(15) The device 10 generally corresponds to a direction finder 30 as will be described hereafter with respect to FIG. 2 in which a flow-chart is shown that illustrates a method of timeslot-wise detection of at least one radio signal in the cellular radio network.

(16) Accordingly, the device 10 may have a directional antenna unit 32. The directional antenna unit 32 may be separately formed with respect to the radio antennas 16, 20. Alternatively, the radio antennas 16, 20 correspond to the directional antenna unit 32 as shown in the embodiment of FIG. 1.

(17) In general, the directional antenna unit 32 may comprise several antenna elements, for example at least one of the radio antennas 16, 20 or rather all radio antennas 16, 20.

(18) The respective method shown in FIG. 2 and described hereinafter can generally be performed by the device 10 shown in FIG. 1.

(19) In a first step S1, a radio signal is received via the radio antennas 16, 20, namely by two separate radio antennas 16, 20, wherein the radio signal is assigned to the cellular radio network.

(20) In a second step S2, the radio signal received by the radio antennas 16, 20 is forwarded to the dedicated radio receivers 14, 18 connected to the corresponding radio antenna 16, 20.

(21) In a third step S3, the radio signal forwarded to the respective radio receivers 14, 18 is processed internally by each of the radio receivers 14, 18. In some embodiments, the radio receivers 14, 18 each measure the radio signal received so as to gather information that is forwarded to the at least one evaluation unit 22 connected to the radio receivers 14, 18.

(22) Each of the radio receivers 14, 18 may obtain baseband data or rather a baseband signal assigned to the radio signal received via the corresponding radio antenna 16, 20.

(23) The information gathered may be assigned to time information, amplitude information and/or phase information which may be used for direction finding purposes.

(24) In some embodiments, the radio receivers 14, 18 each provide a time stamp to the respective radio signal received by the corresponding radio antenna 16, 20, namely the baseband data processed.

(25) In a fourth step S4, the evaluation unit 22 evaluates the data received from the radio receivers 14, 18. In some embodiments, the data is assigned to the radio signal received by the corresponding radio antennas 16, 20.

(26) The evaluation unit 22 synchronizes each of the radio receivers 14, 18 with a preconfigured frame structure, namely the arrangement of the time slot(s) used for uplink signals as well as downlink signals. The preconfigured frame structure may be derived from the radio signal received during the evaluation step performed by the evaluation unit 22 and/or the measuring step done by the radio receivers 14, 18.

(27) Alternatively, the user may have selected a certain communication standard to be investigated at the beginning, particularly manually, such that a certain preconfigured frame structure is expected due to the communication standard under investigation.

(28) During the synchronizing step, the radio receivers 14, 18 may be synchronized with a system clock and/or a timing source of the respective cellular radio network. The system clock or rather timing source is based on the application or rather the communication standard under investigation which in turn is associated to the cellular radio network.

(29) In other words, the preconfigured frame structure used for synchronizing the radio receivers 14, 18 corresponds to the respective communication standard since the communication standard is assigned to the cellular radio network. For instance, the radio receivers 14, 18 are synchronized with an internal clock of the device 10.

(30) In a fifth step S5, the evaluation unit 22 selects at least one identical time slot out of the frame structure at the respective radio receivers 14, 18 each, for example all radio receivers 14, 18. This selection is done after the radio receivers 14, 18 were synchronized with the preconfigured frame structure. The selected identical time slot may correspond to a time slot that is assigned to an uplink.

(31) Put it another way, the evaluation unit 22 selects at least one specific time slot at each of the radio receivers 14, 18 such that an identical time slot of the previously synchronized radio receivers 14, 18 is selected.

(32) A trigger, for instance a gated trigger or a periodic trigger (10 ms), may be applied on the radio signal received in order to identify the different time slots, for example time slot(s) assigned to uplink. This is schematically illustrated in FIG. 3 wherein the time slots assigned to uplink are marked appropriately. The trigger may be applied in a zero span operation mode of the device 10 in which no sweeping takes place. In other words, the device becomes 10 a fixed-tuned radio receiver system. Certain gate settings may be selected to determine gate delay and gate length.

(33) The specific time slot(s) can be identified visually on the display 26 of the device 10 when displaying the radio signal on which the trigger is applied as indicated in FIG. 3.

(34) In addition, a sweep time may be adjusted manually. Hence, visualization and selection of the respective time slot, namely a time slot assigned to uplink, become easier.

(35) Gate delay and gate length can be retrieved from the two vertical lines shown on the display 26 in the zero span operation mode of the device 10. The gate delay can be retrieved on the left and the gate length can be retrieved on the right; please refer to FIG. 3. The gate length may typically be in the order of 1 ms per uplink time slot.

(36) The gated trigger ensures that at least one specific time slot, in particular a time slot assigned to uplink, is selected from the frame structure. This enables the user to identify a potential interferer in the spectrum received as illustrated in FIGS. 4 and 5.

(37) In FIG. 4, the spectrum received is shown without any trigger applied whereas the same spectrum is shown in FIG. 5 when the trigger, for example a gated trigger, is applied for identifying time slot(s) assigned to uplink.

(38) In a sixth step S6, timing information of the selected time slot, namely the identical time slot, is obtained by analyzing the baseband data or rather the baseband signals obtained from the radio receivers 14, 18.

(39) The timing information may be provided from the first radio receiver 14 to the second radio receiver 18. Alternatively or additionally, the timing information is provided from the second radio receiver 18 to the first radio receiver 14. Alternatively or additionally, the timing information is provided from the first radio receiver 14 to the central unit 28. Alternatively or additionally, the timing information is provided from the second radio receiver 18 to the central unit 28.

(40) Accordingly, different possibilities are provided wherein the timing information is forwarded or rather exchanged for calculating a time difference of arrival (TDoA). Hence, the device 10 is configured to determine a time difference of the arrival times of the radio signals at the respective radio antennas 16, 20.

(41) The radio receivers 14, 18 each provide a time stamp to the respective baseband signals or rather baseband data wherein the at least one evaluation unit 22 is configured to correlate the data or rather signals in order to calculate a time difference of arrival (TDoA) of the radio signal at the separate radio antennas 16, 20.

(42) As mentioned above, the timing information may be forwarded from the first radio receiver 14 to the central unit 28. Alternatively or additionally, the timing information may be forwarded from the second radio receiver 18 to the central unit 28. Furthermore, the timing information may be exchanged among the radio receivers 14, 18, namely from the first radio receiver 14 to the second radio receiver 18 or vice versa.

(43) The calculated time difference of arrival (TDoA) can be used for direction finding the emitter of the at least one radio signal in order to locate the emitter in an appropriate manner.

(44) Accordingly, the time difference of arrival is calculated in the specific time slot selected previously, namely the identical time slot, so that information used for direction finding is obtained in the respective time slot.

(45) During the evaluation, at least one interference is detected in the radio signal, namely an interfering signal portion that may disturb the wanted signal(s) of the cellular radio network. While detecting the interference, an interfering emitter may be located due to the direction finding.

(46) In some embodiments, with the gated trigger enabled, the device 10 will output all signals in the specific time slot, both normal traffic and other signals such as interferers.

(47) The time difference of arrival calculated may be displayed or rather post-processed irrespective of the kind of signal the radio signal received relates to. Thus, a wanted signal as well as an interfering signal will be displayed or post-processed. However, the post-processing of the signals may be different depending on their respective kind.

(48) For instance, the time difference of arrival calculated or rather a result of the direction finding is displayed graphically on the display 26. For this purpose, the evaluation unit 22 may forward the respective information to the display 26 for visualizing purposes.

(49) The graphic illustration on the display 26 may be an azimuth dial, an illustration of the respective direction and/or a signal-beam. Simultaneously, a map is displayed so that the user of the device 10 is enabled to identify the direction in a faster and simpler manner. In addition, a triangulation may be displayed on the map, for example wherein the map is a heat map.

(50) Further, the emitter detected is written to a flag so that the respective information may be stored. In addition, this information may also be displayed on the display 26.

(51) In some embodiments, the time difference of arrival calculated or rather the result of the direction finding may be post-processed by the post-processor 24.

(52) For instance, a filter or rather a trigger may be applied on the time difference of arrival calculated or rather the result of the direction finding. Hence, noise can be eliminated by post-processing techniques.

(53) Since the direction finding of an emitter of the at least one radio signal takes place in the selected time slot being a specific one, it is ensured that an interfering signal may be detected in a faster and simpler manner since the time slot selected out of the frame structure may be a time slot assigned to uplink.

(54) Accordingly, direction finding of a radio emitter, namely an emitter of a radio signal, is improved in a radio network based on time-slot technique such as a time domain radio network.

(55) The evaluation unit(s) 22, central unit 28, and/or post-processor 24 or other components of the timeslot-wise detection device described herein may include, in some embodiments, logic for implementing the technologies and methodologies described herein. This logic of these components can be carried out in either hardware or software, or a combination of hardware and software. In some embodiments, one or more of these components includes one or more computing devices such as a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or the like, or any combinations thereof, and can include discrete digital or analog circuit elements or electronics, or combinations thereof.

(56) In an embodiment, one or more of these components includes a microprocessor and a memory storing logic modules and/or instructions. In an embodiment, one or more of these components includes one or more ASICs having a plurality of predefined logic components. In an embodiment, one or more of these components includes one or more FPGA having a plurality of programmable logic components. In an embodiment, one or more of these components includes hardware circuit implementations (e.g., implementations in analog circuitry, implementations in digital circuitry, and the like, and combinations thereof). In an embodiment, one or more of these components includes combinations of circuits and computer program products having software or firmware instructions stored on one or more computer readable memories that work together to cause a device to perform one or more methodologies or technologies described herein.

(57) The present application may also reference quantities and numbers. Unless specifically stated, such quantities and numbers are not to be considered restrictive, but exemplary of the possible quantities or numbers associated with the present application. Also in this regard, the present application may use the term “plurality” to reference a quantity or number. In this regard, the term “plurality” is meant to be any number that is more than one, for example, two, three, four, five, etc. The terms “about,” “approximately,” “near,” etc., mean plus or minus 5% of the stated value. For the purposes of the present disclosure, the phrase “at least one of A, B, and C,” for example, means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all further possible permutations when greater than three elements are listed.

(58) The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure which are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure, as claimed.