OTA traffic analysis device and OTA traffic analysis method

Abstract

To provide an OTA traffic analysis device and an OTA traffic analysis method that enable efficient and highly accurate observation of OTA traffic from intermittently received multi-wave mixed signals, without affecting the wireless communication system in operation.SOLUTION: An OTA traffic analysis device 1 intermittently captures a multi-wave mixed signal generated by wireless communication between a base station and a wireless terminal in an OTA environment, and analyzes OTA traffic on the basis of separated signals separated for each signal source from the intermittently captured received signal. The OTA traffic analysis device includes a device control unit 31a that controls a signal capture time and a reception interval of the multi-wave mixed signal, and a PDU estimation unit 43 that selects separated signals for each component of the same communication, estimates signal patterns of the selected separated signals for each component of the same communication, and estimates PDUs transmitted and received by wireless communication on the basis of the estimated separated signal patterns.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an OTA traffic analysis device and an OTA traffic analysis method that intermittently receive wireless signals in an OTA (Over The Air) space where multiple wireless terminals transmit and receive wireless signals, and analyze OTA communication traffic from the received wireless signals. [Background technology]

[0002] The next-generation communications standard, 5G, is beginning to be put into practical use, and in order to meet the wide-ranging needs of 5G, studies are underway on local 5G, which can be flexibly built and used by various entities such as local governments and regional companies.

[0003] In order to cope with the further rapid increase in mobile traffic, the application of InBand Full-Duplex (IBFD), a highly efficient frequency utilization technology, is being considered.

[0004] IBFD can ideally double the frequency efficiency compared to existing duplex methods, but there is a problem of a lot of new interference occurring, so a control technology is needed to obtain various interference amounts and determine whether IBFD can be applied based on the results. To achieve this, interference monitoring technology is needed to grasp the wireless conditions in time and space, for example, of 5G wireless terminals or terminals of other standards, and to measure the interference conditions of radio waves emitted into space from multiple terminals at high speed and with high accuracy, and as part of this, a system is needed to estimate the direction of arrival of electromagnetic waves at any point.

[0005] Known conventional systems for estimating the direction of arrival include systems that estimate the direction of arrival of electromagnetic waves based on received signals at the same positions of multiple antennas that each receive three orthogonal polarized signals (e.g., Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-96191 Summary of the Invention [Problem to be solved by the invention]

[0007] In the radio wave arrival direction estimation system described in Patent Document 1, for example, three antennas are moved sequentially to the same measurement position, and the arrival direction of the electromagnetic wave at that position can be accurately estimated using all (three) polarized components received at that same position.

[0008] However, conventional direction-of-arrival estimation systems do not take into consideration a function for analyzing communication traffic such as the length, interval, and amount of communication data by an incoming signal from the incoming signal received at the relevant position. Therefore, in an OTA environment in which multiple wireless terminals transmit and receive wireless signals to each other, conventional direction-of-arrival estimation systems have difficulty in responding to an operation in which the wireless signal is received at a desired observation point and communication data by the wireless signal, for example, a protocol data unit (PDU) such as a packet or a frame, is estimated from the received wireless signal.

[0009] One of the factors that hinder the above operation is, for example, signal processing capability. In the above-mentioned conventional direction-of-arrival estimation system, in order to analyze communication traffic (OTA traffic) in an OTA environment, it is highly likely that the existing processing capability is not sufficient to constantly receive and process a multi-wave mixed signal that is a mixture of wireless signals sent from multiple wireless terminals. If intermittent reception processing of wireless signals is performed to avoid this, there is a problem that the OTA traffic cannot be analyzed efficiently and the analysis accuracy is reduced. In addition, there is a risk that the observation may affect the wireless communication system in operation.

[0010] The present invention has been made to solve such conventional problems, and has an object to provide an OTA traffic analysis device and an OTA traffic analysis method that enable efficient and highly accurate observation of OTA traffic from an intermittently received multi-wave mixed signal without affecting the wireless communication system in progress. [Means for solving the problem]

[0011] In order to solve the above problems, an OTA traffic analysis device according to claim 1 of the present invention is an OTA traffic analysis device (1, 1A) that, in an OTA environment in which wireless communication is performed between a base station (B1) and a plurality of wireless terminals (A1), intermittently captures a multi-wave mixed signal in which wireless signals transmitted and received between the base station and the wireless terminals are mixed, and analyzes communication traffic of the wireless communication based on separated signals separated for each signal source (110) that is the wireless terminal from received signals intermittently acquired in response to the capture, and includes a capture control means (31a) that controls a signal capture time and a reception interval of the multi-wave mixed signal, and a capture control means (31b) that controls a reception interval of the separated signals separated after capture. Signals arriving from the signal source The signal pattern of the selected separated signal is selected for each of the same Signals arriving from the signal source and estimating the same signal pattern for each of the separated signals based on the estimated signal pattern of the separated signals. Signals arriving from the signal source and a PDU estimation means (43, 43A) for estimating a protocol data unit (PDU) transmitted and received by the wireless communication for each of the plurality of frames.

[0012] With this configuration, the OTA traffic analysis device according to claim 1 of the present invention estimates the signal pattern of the separated signals of components of the same communication separated from the intermittently received received signal, and then detects the same communication from the signal pattern. Signals arriving from the signal source This makes it possible to easily estimate the length and interval of each PDU, and enables OTA observation of the number of wireless terminals and the communication volume of each wireless terminal, without affecting the operation of a wireless communication system that uses a specific frequency.

[0013] Moreover, the OTA traffic analysis device according to claim 2 of the present invention may further include a setting means (41) for setting parameters related to the analysis of the communication traffic, wherein the setting means sets a frequency, a data rate, the signal capture time, the reception interval, a maximum PDU size, a minimum PDU size, and a minimum inter-PDU gap length as the parameters, the capture control means controls so that the capture is performed at the set signal capture time and reception interval, and the PDU estimation means continues the PDU estimation process until an estimated PDU that matches the set frequency, data rate, maximum PDU size, minimum PDU size, and minimum inter-PDU gap length is acquired.

[0014] With this configuration, the OTA traffic analysis device according to claim 2 of the present invention can easily estimate a PDU that matches a desired frequency, a desired data rate, a desired size, etc. by setting parameters using the setting means.

[0015] The OTA traffic analysis device according to claim 3 of the present invention further comprises an arrival direction estimation means (24) for estimating the arrival direction of the separated signal, and a signal strength estimation means (25) for estimating the signal strength of the separated signal, and the PDU estimation means estimates the same PDU by taking into account the arrival direction and signal strength of the separated signal. Signals arriving from the signal source and selecting the same signal based on the signal pattern of the selected separation signal. Signals arriving from the signal source The PDU transmitted and received via the wireless communication may be estimated for each of the plurality of frames.

[0016] With this configuration, the OTA traffic analysis device according to claim 3 of the present invention uses the arrival direction estimation means and signal strength estimation means of an existing blind signal estimation device in combination, and takes into account the estimation results of the arrival direction and signal strength of the separated signals to perform the same For each signal coming from the signal source By estimating the signal pattern of the separated signal and then estimating the PDU, the accuracy of PDU estimation can be improved without complicating the configuration compared to the case where the estimated results of the arrival direction and signal strength are not taken into account.

[0017] In the OTA traffic analysis device according to claim 4 of the present invention, the setting means further sets a threshold for an arrival angle, and the PDU estimation means classifies, among the separated signals captured at adjacent signal capture times, the separated signals whose arrival directions are within a range of the threshold, into a single signal. Signals arriving from the signal source The configuration may be such that the first selection is made as follows.

[0018] With this configuration, the OTA traffic analysis device according to claim 4 of the present invention can set a threshold for the arrival angle, and can analyze separated signals within the angle range of the threshold as a single signal. Signals arriving from the signal source This makes it easy to select each device individually, and also speeds up the analysis of communication traffic in an OTA environment.

[0019] In addition, in the OTA traffic analysis device of claim 5 of the present invention, the PDU estimation means may be configured to determine whether the separated signal is the beginning of the PDU, a continuation of the PDU, or the end of the PDU, depending on whether the separated signal has been received, is continuing to be received, or has stopped being received, corresponding to the signal capture time, and to estimate the length and interval of the PDU based on the result of the determination.

[0020] With this configuration, the OTA traffic analysis device according to claim 5 of the present invention can simplify the processing up to obtaining the PDU (estimated PDU) obtained as an estimation result, and can also shorten the processing time.

[0021] In order to solve the above-mentioned problems, an OTA traffic analysis method according to claim 6 of the present invention is an OTA traffic analysis method for intermittently capturing a multi-wave mixed signal in which radio signals transmitted and received between a base station (B1) and a plurality of wireless terminals (A1) are mixed in an OTA environment in which wireless communication is performed between the base station and the wireless terminals, and analyzing communication traffic of the wireless communication based on separated signals separated for each signal source (110) that is the wireless terminal from received signals intermittently acquired in response to the capture, the OTA traffic analysis method including a capture control step (S3) for controlling a signal capture time and a reception interval of the multi-wave mixed signal, and a capture control step (S4) for controlling the reception interval of the separated signals separated after the capture. Signals arriving from the signal source The signal pattern of the selected separated signal is selected for each of the same Signals arriving from the signal source and estimating the signal pattern of the separated signals for each of the plurality of signals (S61 to S66). Signals arriving from the signal source and a PDU estimation step (S7) of estimating a protocol data unit (PDU) transmitted and received by the wireless communication for each of the plurality of frames.

[0022] With this configuration, the OTA traffic analysis method according to claim 6 of the present invention estimates a signal pattern of a separated signal of components of the same communication separated from an intermittently received signal, and then detects the same communication from the signal pattern. Signals arriving from the signal source This makes it possible to easily estimate the length and interval of each PDU, and enables OTA observation of the number of wireless terminals and the communication volume of each wireless terminal, without affecting the operation of a wireless communication system that uses a specific frequency. Effect of the Invention

[0023] The present invention can provide an OTA traffic analysis device and an OTA traffic analysis method that enable efficient and highly accurate observation of OTA traffic from an intermittently received multi-wave mixed signal without affecting a wireless communication system in operation. [Brief description of the drawings]

[0024] [Figure 1]1 is a conceptual diagram for explaining a wireless environment in an OTA space in which an OTA traffic analysis device according to the present invention is arranged. [Diagram 2] FIG. 1 shows an example of the structure of a wireless frame that transmits and receives a PDU that is to be analyzed by the OTA traffic analysis device of the present invention, where (a) shows the structure of the entire wireless frame, and (b) to (f) show the structure of slots each having a different number of symbols. [Diagram 3] FIG. 13 is a timing chart showing the PDU estimation process performed by the OTA traffic analysis device of the present invention, in which (a) to (f) show each PDU pattern to be estimated, (g) shows a multi-wave mixed signal containing a mixture of wireless signals transmitting and receiving each PDU pattern, (h) shows a received signal obtained by intermittently capturing the multi-wave mixed signal, (i) shows a separated signal separated for each signal source from the received signal, and (j) shows a timing chart of an estimated PDU estimated from the separated signal. [Figure 4] 4A and 4B are timing charts showing a method for capturing a mixed signal of multiple waves in the OTA traffic analysis device according to the present invention, where FIG. 4A shows an example of a sequential processing method, and FIG. 4B shows an example of a pipeline processing method. [Diagram 5] FIG. 13 is a timing chart showing the PDU estimation process performed by the OTA traffic analysis device of the present invention, taking into account the estimated direction of arrival and signal strength of a separated signal from a received signal, in which (a) shows the signal capture time, (b) to (g) show the respective separated signals, and (h), (i), and (j) show the timing charts of each piece of data that has each separated signal as a component. [Figure 6] 1 is a timing chart showing an example of the relationship between the size of a PDU to be analyzed by an OTA traffic analysis device according to the present invention and a signal capture interval. [Figure 7] 1 is a block diagram showing a functional configuration of an OTA traffic analysis device according to a first embodiment of the present invention. [Figure 8] 5 is a flowchart showing a PDU estimation processing operation in a PDU estimation unit of the OTA traffic analysis device according to the first embodiment of the present invention. [Figure 9] 9 is a flowchart showing a procedure of a separated signal pattern determination process for estimating a PDU for each set of separated signals selected as components of the same communication in step S7 of FIG. 8. [Figure 10] 10A, 10B, 10C, and 10D show an example of the correspondence between a received signal, a separated signal pattern, and an estimated PDU in the PDU estimation process of the OTA traffic analysis device of the first embodiment of the present invention, in which (a), (b), (c), and (d) show the relationship between each separated signal that is received at different times and is no longer received at different times, and an estimated PDU estimated based on the judgment result by the judgment process procedure shown in FIG. [Figure 11] FIG. 11 is a block diagram showing a functional configuration of an OTA traffic analysis device according to a second embodiment of the present invention. [Figure 12] 10 is a flowchart showing a PDU estimation process operation in a PDU estimation unit of an OTA traffic analysis device according to a second embodiment of the present invention. [Figure 13] FIG. 11 is a timing chart showing PDU estimation processing by an OTA traffic analysis device according to a second embodiment of the present invention, in which (a) shows intermittently performed signal reception, (b) shows signal processing for the intermittently received signal, (c) shows a separated signal separated for each signal source by signal processing, (d) shows a PDU estimation processing based on the separated signal, and (e) shows a timing chart of an estimated PDU obtained by the PDU estimation processing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of an OTA traffic analysis device and an OTA traffic analysis method according to the present invention will be described with reference to the drawings.

[0026] (overview) The OTA traffic analysis device 1 according to the present invention (here, the OTA traffic analysis device 1 according to the first embodiment is illustrated, but the same applies to the OTA traffic analysis device 1A according to the second embodiment) is arranged and operated in an OTA space in which wireless communication is performed between a wireless base station B1 (or an exchange B2) and various wireless terminals A11, A12, A13, and A14, for example, as shown in FIG. 1. The wireless terminals A11, A12, A13, and A14 transmit and receive wireless signals (multiplexed by OFDM, converted into RF signals, and transmitted. Hereinafter, they may be referred to as OFDM signals) with the base station B1, and can communicate with a communication partner via the base station B1. Here, the wireless terminals A11, A12, A13, and A14 can communicate with a communication terminal in a network connected to the base station B1, for example, via the base station B1. In addition, the wireless terminals A11, A12, A13, and A14 can also communicate with other wireless terminals via the base station B1. In FIG. 1, wireless terminals A11, A12, A13, and A14 (hereinafter, these may be collectively referred to as wireless terminal A1) include various wireless communication devices such as tablet terminals, smartphones, personal computers (PCs), and wireless routers.

[0027] In the above-mentioned OTA environment, when the base station B1 and multiple wireless terminals A1 simultaneously transmit and receive wireless signals (OFDM signals), a wireless communication situation occurs in which these wireless signals are mixed. The OTA traffic analysis device 1 according to the present invention has an arrival direction / signal strength estimation function (corresponding to an arrival direction estimation processing unit 24 and a signal analysis unit 25 described later) that receives a multi-wave mixed signal in which wireless signals (OFDM signals) transmitted from each wireless terminal A1 as a signal source 110 are mixed during communication between the base station B1 and the wireless terminal A1 at an appropriate placement point within the observation area 6, separates each mixed wireless signal from the multi-wave mixed signal, and estimates the arrival direction and signal strength of each separated signal (separated signal), i.e., each signal source 110.

[0028] Moreover, the OTA traffic analysis device 1 according to the present invention further has an OTA traffic analysis function that analyzes communication traffic relating to communication between the base station B1 and the wireless terminal A1 based on, for example, the result of estimation by the direction of arrival / signal strength estimation function of the signal arrival direction and signal strength for each signal source 110. In the present invention, the OTA traffic analysis function is particularly assumed to be a data estimation function that estimates the interval and length of communication data transmitted and received by communication between the base station B1 and the wireless terminal A1.

[0029] <Data estimation function> In the present invention, for example, a wireless frame having a structure shown in FIG. 2 is used for transmitting and receiving communication data between the base station B1 and a plurality of wireless terminals A1.

[0030] FIG. 2 shows an example of the configuration of a radio frame used in IBFD communication of the 5G NR standard. As shown in FIG. 2(a), the radio frame has a length of, for example, 10 milliseconds (ms) and is composed of 10 subframes of equal time length, for example, 1 ms. There are subframes in which one slot is composed of one set of 14 symbols (see FIG. 2(b)), two sets of 14 symbols (see FIG. 2(c)), four sets of 14 symbols (see FIG. 2(d)), eight sets of 14 symbols (see FIG. 2(e)), and 16 sets of 14 symbols (see FIG. 2(f)). The symbol configuration is, for example, one set of 14 symbols for low data rate operation and 16 sets of 14 symbols for high data rate operation.

[0031] In the IBFD communication of the 5G standard, for example, packet data is transmitted and received between the base station B1 and the wireless terminal A1 using the wireless frame shown in FIG. 2. Examples of data types transmitted and received by packet data include email, data, voice, images, and videos. During wireless communication between the base station B1 and the wireless terminal A1, the transmitting side samples, quantizes, encodes, encrypts, and compresses the data to be transmitted based on the protocol specifications, packetizes the data, assembles the data into PDUs, and transmits the data as wireless signals through modulation. On the other hand, the receiving side receives the wireless signal sent from the transmitting side, demodulates the data, reconstructs the PDU based on the protocol specifications, and then expands and decodes the data to reproduce the original data.

[0032] When various data are wirelessly transmitted between base station B1 and wireless terminal A1 using the above-mentioned wireless frames, the OTA traffic analysis device 1 of the present invention intermittently captures a multi-wave mixed signal containing a mixture of wireless signals transmitted and received between base station B1 and wireless terminal A1 during communication at predetermined intervals for a predetermined length of time, and performs processing to separate signals for each signal source 110 mixed in the multi-wave mixed signal.

[0033] 3, communication between base station B1 and wireless terminal A1 in observation area 6 may involve, for example, transmission and reception of signals having PDU patterns #1 to #6 as shown in Fig. 3(a) to (f). During communication of signals having PDU patterns #1 to #6, an OTA traffic analysis device 1 placed at a certain point in observation area 6 may receive a transmission signal (multiple-wave mixed signal) in which signals having PDU patterns #1 to #6 are mixed, as shown in Fig. 3(g), for example.

[0034] In such an OTA environment, the OTA traffic analysis device 1 repeatedly captures a multi-wave mixed signal for a reception time (signal capture time) Trx (Trx1, Trx2, Trx3, ...) at each reception interval Tint (Tint1, 2, 3, ...), as shown in Figure 3(h), for example.

[0035] As a method for capturing a signal containing multiple waves, for example, a sequential processing method and a pipeline processing method can be applied. The sequential processing method is a method in which capture is performed sequentially at an appropriate time interval, as shown in FIG. 4(a), for example. When the capture accuracy of a signal containing multiple waves is not important, it is possible to reduce the processing load by setting the time interval to a wide value. The pipeline method is a method in which the time interval between captures is made shorter than that of the sequential processing method, as shown in FIG. 4(b), and the total capture time is made longer than that of the sequential processing method. By setting the time interval to an appropriate short value, the processing load increases, but the capture accuracy can be improved compared to the sequential processing method. In the present invention, both the sequential processing method and the pipeline method can be applied, but the following description is based on the assumption that the sequential processing method is applied.

[0036] In accordance with the capture of a multiple-wave mixed signal (transmission signal) by the sequential processing method shown in Fig. 3(h), the OTA traffic analysis device 1 according to the present invention repeatedly performs a signal separation process for separating signals for each signal source 110 mixed therein from the received signal (multiple-wave mixed signal) and a process for acquiring signals (separated signals) separated by the signal separation process, as shown in Fig. 3(i), every time it finishes receiving a multiple-wave mixed signal at a receiving interval Tint1, 2, 3, .... In Fig. 3(i), the processing time Tp of the signal separation process performed sequentially is represented by Tp1, Tp2, Tp3, ..., and the time Ts of the acquired separated signals is represented by Ts1, Ts2, Ts3, ....

[0037] Furthermore, as shown in Fig. 3(j), the OTA traffic analysis device 1 according to the present invention performs a PDU estimation process for estimating the pattern of PDUs transmitted and received in the forms of Figs. 3(a) to 3(f) based on the separated signals with respective time lengths Ts1, Ts2, Ts3,... obtained by the signal separation process shown in Fig. 3(i). A PDU is a unit of data transmission and reception grouped together according to a protocol (communication convention) specification in data communication, and an example thereof is a packet. The PDU (estimated PDU) estimated by the PDU estimation process shown in Fig. 3(j) is desirably approximated as closely as possible to the PDU patterns #1 to #6 shown in Figs. 3(a) to 3(f) from the viewpoint of OTA traffic analysis accuracy.

[0038] Thus, the OTA traffic analysis device 1 according to the present invention has a PDU estimation process function as the above-described data estimation function for estimating a PDU based on the separated signals separated for each signal source 110 from the multi-wave mixed signal intermittently captured.

[0039] <PDU estimation process function> The PDU estimation process function selects partial constituent (fragment) elements (corresponding to the communication data received at the capture timings Trx1, Trx2, Trx3,... respectively) of the PDU patterns #1 to #6 (see Figs. 3(a) to 3(f)) transmitted and received by the ongoing wireless communication for each constituent element of the same communication, and performs a PDU estimation process for recognizing an estimated PDU for each different communication from the fragment elements for each selected same-communication constituent element.

[0040] In addition, the above-mentioned various data (email, data, voice, image, video, etc.) transmitted and received between the base station B1 and the wireless terminal A1 can be roughly inferred from the data type in terms of the length (maximum size, minimum size) and interval (gap between PDUs) of the PDU when transmitted and received in a wireless frame (see FIG. 2), or the so-called data pattern such as the data rate. In other words, when the type of communication data wirelessly communicated between the base station B1 and the wireless terminal A1 is known to some extent, even if the communication data is received intermittently, the entire length and interval of the PDU can be estimated from the intermittently received received signal.

[0041] As an example, a PDU estimation process performed in association with the estimated results of the arrival direction and signal strength of the separated signals will be described with reference to Fig. 5. Note that, for the capture execution timing shown in Fig. 5(a), the capture start times (times corresponding to the starting points of the reception times Trx1, Trx2, Trx3, ... in Fig. 3(h)) are represented as t1, t2, t3, .... Also, for the separated signals shown in Fig. 5(b) to (g), the signal processing times after the capture start times t1, t2, t3, ... (corresponding to the signal separation processing time Tp shown in Fig. 3(i)) are omitted, and each is associated with the estimated results of the arrival direction and signal strength.

[0042] In the process of estimating a PDU from a separated signal (see Figures 5(b) to (g)) associated with the estimated results of the arrival direction and signal strength, the OTA traffic analysis device 1 of the present invention estimates the arrival directions A, B, C, A', B', C', ... and signal strengths of signals (separated signals) Sa, Sb, Sc, Sa', Sb', Sc', ... separated for each signal source 110 from a multiple-wave mixed signal received during communication between the base station B1 and the wireless terminal A1, and performs a process of storing the separated signals Sa, Sb, Sc, Sa', Sb', Sc', ... together with the estimated results of the arrival directions A, B, C, A', B', C', ... and signal strengths in a database 33 (see Figure 7) in association with the capture start times t1, t2, t3, ...

[0043] In accordance with this process, the PDU estimation processing function continuously searches the stored separated signals Sa, Sb, Sc, Sa', Sb', Sc', ... and their arrival directions A, B, C, A', B', C', ... and estimated signal strengths for each capture start time t1, t2, t3, ... (see Fig. 5(a) to (g)), and selects components of the same communication from each of the searched multiple separated signals Sa, Sb, Sc, Sa', Sb', Sc', .... The arrival direction is referred to as a parameter for selecting components of the same communication.

[0044] Specifically, assuming that capture progresses sequentially from time t1 to time t7 in Figure 5(a), for the separated signals Sa, Sb, Sc, Sa', Sb', Sc', ... shown in Figures 5(b) to (g), the arrival directions A, B, and C are captured for the separated signals Sa, Sb, and Sc received and separated at time t1, respectively.

[0045] Similarly, for the received and separated separated signals Sb and Sa' at time t2, arrival directions B and A' are captured, respectively, for the received and separated separated signals Sc, Sa' and Sb' at time t3, arrival directions C, A' and B' are captured, respectively, for the received and separated separated signals Sa, Sb' and Sc' at time t4, arrival directions A, B' and C' are captured, respectively, for the received and separated separated signals Sa, Sb and Sc' at time t5, arrival directions A, B and C' are captured, respectively, for the received and separated separated signals Sc at time t6, arrival direction C' is captured, and for the received and separated separated signals Sa', Sb' and Sc' at time t7, arrival directions A', B' and C' are captured, respectively.

[0046] Here, for example, when the angle difference between the directions (angles) of arrival direction A and arrival direction A' is within a preset threshold (threshold angle), it can be inferred that separated signal Sa of arrival direction A and separated signal Sa' of arrival direction A' are signals (components of the same communication) arriving from the same signal source 110. This inference method also applies to separated signal Sb of arrival direction B and separated signal Sb' of arrival direction B', and separated signal Sc of arrival direction C and separated signal Sc' of arrival direction C'.

[0047] That is, in the OTA traffic analysis device 1 according to the present invention, a threshold angle is set in advance, and as the multiple wave mixed signal is captured and separated in the order of times t1, t3, t4, t5, t6, t7, ... at the timings shown in FIG. 5(a), the separated signals before and after whose estimated direction of arrival is within the range of the threshold angle can be extracted as components of the same communication.

[0048] Specifically, in the examples of Figures 5(b) to (g), separated signals Sa and Sa' can be extracted as components of the same communication. Similarly, separated signals Sb and Sb', and separated signals Sc and Sc' can be extracted as components of another same communication. In Figures 5(b) to (g), the blank areas corresponding to times t1, t3, t4, t5, t6, t7, ... indicate a state in which a separated signal does not exist, and the areas indicated by dotted lines indicate a state in which a separated signal could not be received for some reason (a state of reception failure).

[0049] According to the result of selecting components of the same communication based on the threshold angle described above, separated signals Sa and Sa' are selected as the same communication element consecutively, except for time t6, among times t1, t3, t4, t5, t6, t7, ... in FIG. 5(a). Separated signals Sb and Sb' are selected as another identical communication element consecutively, except for time t6 (reception miss). Separated signals Sc and Sc' are further selected as another identical communication element consecutively, except for time t2 (reception miss).

[0050] 5, (h), (i), and (j) show an example of a transmission / reception pattern of packet data A, B, and C transmitted and received between base station B1 and wireless terminal A1 in observation area 6 using a wireless frame having the configuration shown in Fig. 2. The section of time width t0 enclosed by a dotted line in Fig. 5(h), (i), and (j) corresponds to the intermittent capture section spanning times t1 to t7 shown in Fig. 5(a).

[0051] According to the timing chart shown in FIG. 5, in the OTA traffic analysis device 1 of the present invention, a multi-wave mixed signal containing packet data A, B, and C transmitted and received between base station B1 and wireless terminal A1 is intermittently captured over a period wider than time width t0, fragments (separated signals) of each component of packet data A, B, and C are extracted, and these separated signals are selected for each component of the same communication, making it possible to estimate the interval and length of packet data A, B, and C (PDU) which includes the separated signal as part of it.

[0052] Here, in order to estimate the interval and length of the PDU after selecting a separated signal for each component of the same communication, it is necessary to estimate for each selected separated signal whether the separated signal is the beginning, end, or continuation part of the PDU, etc.

[0053] The reason for this will be described with reference to Fig. 6. The size of the PDU that is the subject of OTA traffic analysis by the OTA traffic analysis device 1 according to the present invention and the signal capture interval have a relationship as shown in Fig. 6, for example.

[0054] As shown in the upper part of Fig. 6, PDUs such as PDUs #1, #2, #3, ... may be appropriately transmitted at different intervals (g1, g2, ...) and different time lengths. On the other hand, in the OTA traffic analysis device 1 according to the present invention, as shown in the lower part of Fig. 6, a multi-wave mixed signal in which PDUs #1, #2, #3, ... are mixed is intermittently received for a certain time length at certain intervals i1, i2, i3, i4, ... and separated for each signal source 110, and the separated signals are selected for each component of the same communication to extract PDUs #1, #2, #3, ....

[0055] As can be seen from the relationship shown in Figure 6, reception of PDU#1 begins almost at the beginning of capture interval i1, but is not received during capture interval i2. Reception of PDU#2 begins almost at the beginning of capture interval i3, and after being received at the rear end, it is no longer received. Reception of PDU#3 begins a short time after the beginning of capture interval i5, and continues to be received at the rear end.

[0056] In this way, in order to capture PDUs #1, #2, #3, ... with different lengths and intervals at regular intervals i1, i2, i3, i4, ... and estimate the length as accurately as possible, it is useful to estimate, for each separated signal of the selected components of the same communication, whether the separated signal is the head part, continuation part, or end part of the PDU, which is also useful in improving the accuracy of the estimated PDU. Note that the process procedure for determining whether a separated signal is the head part, continuation part, or end part of the PDU will be described in detail later with reference to Fig. 9.

[0057] 5, the PDU estimation process takes into account (associates) the arrival direction and signal strength of the separated signals separated from the received multi-wave mixed signal, but in the present invention, it is not necessarily required to associate the separated signals with the arrival direction and signal strength, and the PDU may be estimated only from the separated signals. This configuration will be described in detail later as a second embodiment.

[0058] (First embodiment) Based on the above-mentioned overview, the configuration of the OTA traffic analysis device 1 according to the first embodiment of the present invention will be described below with reference to Fig. 7. Note that the first embodiment is premised on estimating a PDU from a separated signal associated with the estimation results of the arrival direction and signal strength.

[0059] As shown in FIG. 7, the OTA traffic analysis device 1 according to this embodiment includes an antenna device 10, a blind signal estimation device 20, and a data processing device 30.

[0060] Antenna device 10 receives a multi-wave mixed signal transmitted from multiple signal sources 110 within observation area 6 (see FIG. 1). Specific configurations of antenna device 10 include, for example, a configuration in which three antennas capable of receiving three orthogonal polarized waves are rotated on a rotating body as multiple antenna elements as described in Patent Document 1, or a configuration in which each antenna element of an array antenna is configured as multiple antenna elements.

[0061] The OTA traffic analysis device 1 of this embodiment receives incoming signals from the surrounding wireless environment, i.e., a multi-wave mixed signal that is a mixture of signals transmitted from multiple signal sources 110 within an observation area 6, using multiple antenna elements provided in the antenna device 10, and processes the received signals of each antenna element using a blind signal estimation device 20 and a data processing device 30 to separate the signals transmitted from each signal source 110 and estimate the arrival direction and signal strength of each signal source 110, and estimate a PDU based on the estimated results of the arrival direction and signal strength.

[0062] Moreover, the OTA traffic analysis device 1 according to the present embodiment can be used, for example, in a local 5G environment, and the frequency bands of the incoming signal to be captured are assumed to be, for example, 3.75 GHz, 4.6 GHz to 4.8 GHz, and 28.2 GHz to 29.1 GHz. The OTA traffic analysis device 1 is not limited to use in a local 5G environment, and can also be used in other wireless systems such as WiFi.

[0063] It should be noted that the antenna device 10 is not limited to the above-mentioned configuration in the OTA traffic analysis device 1. As long as it is possible to comprehensively obtain the arrival direction and various characteristics for inter-area terminal-to-terminal interference, inter-base station interference, etc. in the above-mentioned frequency band, various methods can be applied for the type, number, arrangement, driving method, arrival direction estimation method, etc. of the antenna.

[0064] As shown in FIG. 3, the blind signal estimation device 20 includes a frequency conversion unit 21, an AD conversion unit 22, a signal separation unit 23, an arrival direction estimation processing unit 24, and a signal analysis unit 25.

[0065] The frequency conversion unit 21 receives a signal (a mixed signal of multiple waves) received by the antenna device 10, and converts the received signal into an intermediate frequency band signal (IF signal).

[0066] The AD conversion unit 22 converts the received signal, frequency-converted by the frequency conversion unit 21, from an analog signal to a digital signal and outputs the digital signal to the signal separation unit 23. The AD conversion unit 22, together with the antenna device 10 and the frequency conversion unit 21, constitutes a receiving unit 20a.

[0067] The signal separation unit 23 performs signal separation processing to separate a signal transmitted from any one of the multiple signal sources 110 from the digital signal input from the AD conversion unit 22, i.e., the multiple-wave mixed signal received at a specified placement point in the observation area 6.

[0068] The arrival direction estimation processing unit 24 inputs the signals (separated signals) separated by the signal separation unit 23, and performs signal processing to estimate the arrival direction of each input signal. In this signal processing, for example, the beamformer method, the MUSIC method, the ESPRIT method, etc. are applied as algorithms for estimating the arrival direction. In these methods, for example, the horizontal axis is the angle and the vertical axis is the signal level, and an angular spectrum is generated that represents the arrival direction (angle) of an arriving signal in relation to the signal level, and then the peak of the signal level on the vertical axis of the angular spectrum is read, and the angle on the horizontal axis corresponding to the peak is estimated as the arrival direction (angle) of an arriving signal having the angular spectrum. The arrival direction estimation processing unit 24 constitutes the arrival direction estimation means of the present invention.

[0069] The signal analysis unit 25 receives the separated signals from the signal separation unit 23 and performs signal processing to analyze the separated signals for various items. Items to be analyzed (analysis items) include, for example, signal strength. The signal analysis unit 25 corresponds to the signal strength estimation means of the present invention, and constitutes the analysis processing unit 20b together with the above-mentioned signal separation unit 23 and arrival direction estimation processing unit 24.

[0070] The blind signal estimation device 20 is equipped with a frequency conversion unit 21, an AD conversion unit 22, a signal separation unit 23, an arrival direction estimation processing unit 24, and a signal analysis unit 25, and is capable of receiving a multi-wave mixed signal arriving at an installation point within the space of the observation area 6, separating the mixed signals therein, and estimating the arrival direction and signal strength for each separated signal.

[0071] The data processing device 30 is realized by, for example, a PC (personal computer), and performs data processing for analyzing communication traffic (OTA traffic) carried out between wireless terminals A1 (signal sources 110) within the observation area 6 based on the analysis results of the received signal in the blind signal estimation device 20, in particular the estimation results of the signal arrival direction and signal strength. The data processing device 30 is configured to include a control unit 31, a database 33, an input unit 34, and a display unit 35.

[0072] The control unit 31 is configured by, for example, a computer device. This computer device has a CPU (Central Processing Unit) that performs predetermined information processing for realizing the functions of the OTA traffic analysis device 1 and overall control of the antenna device 10 and the blind signal estimation device 20, a non-volatile memory such as a ROM (Read Only Memory) or HDD (Hard Disc Drive) that stores an OS (Operating System) for starting up the CPU, other programs, and control parameters, and a RAM (Random Access Memory) that stores execution codes and data of the OS and applications used by the CPU for operation.

[0073] The above-mentioned computer device functions as the control unit 31 by the CPU executing a program stored in a nonvolatile memory such as a ROM or a HDD using the RAM as a working area. Specifically, the control unit 31 realizes each function of an analysis condition setting unit 41, an antenna control unit 42, a PDU estimation unit 43, and a display control unit 47 as shown in Fig. 7 by the CPU executing each program stored in the nonvolatile memory in the working area of ​​the RAM. Here, the analysis condition setting unit 41 and the antenna control unit 42 constitute a functional unit serving as a device control unit 31a that controls the blind signal estimation device 20, and the PDU estimation unit 43 and the display control unit 47 constitute a functional unit serving as a data control unit 31b that performs data processing related to the OTA traffic analysis.

[0074] The analysis condition setting unit 41 is a functional unit for setting analysis conditions for OTA traffic in the observation area 6, and is capable of setting, for example, the frequency of a radio signal to be analyzed for OTA traffic, and constitutes a setting means of the present invention. The analysis condition setting unit 41 may be configured to set, for example, any one of the 3.7 GHz band, the 4.7 GHz band, and the 28 GHz band as the frequency band to be analyzed for OTA traffic, taking into account the operation of 5G.

[0075] The antenna control unit 42 performs mechanical control of the antenna direction in the antenna device 10, etc.

[0076] The device control unit 31a, which has an analysis condition setting unit 41 and an antenna control unit 42, also has a function of controlling the capture time (reception time Trx in FIG. 3(h)) and reception interval (Tint in FIG. 3(h)) of the multiple wave mixed signal. The device control unit 31a constitutes the capture control means of the present invention.

[0077] The PDU estimation unit 43 sequentially stores in the database 33 signals generated by signal processing in accordance with intermittent reception (capture) of a multiple-wave mixed signal in the blind signal estimation device 20, i.e., the separated signals and the estimation results of the arrival directions and signal strengths of the separated signals, and executes a PDU estimation process for estimating the length and interval of PDUs including the separated signals as some components, based on the stored separated signals and the estimation results of the arrival directions and signal strengths of the separated signals. The PDU estimation unit 43 constitutes the PDU estimation means of the present invention.

[0078] The display control unit 47 controls the display of various information and screens related to the OTA traffic analysis process, such as a setting screen for OTA traffic analysis conditions, a display screen for displaying PDU estimation results, and the like.

[0079] The database 33 is a functional unit for storing various information related to OTA traffic analysis, such as the separated signals output by the signal separation unit 23, the estimated directions of arrival and signal strengths of the separated signals output by the arrival direction estimation processing unit 24 and the signal analysis unit 25, respectively, and the PDU estimation results by the PDU estimation unit 43.

[0080] The input unit 34 is a functional unit for inputting various information such as commands, and is configured with input devices such as a keyboard, a mouse, etc. In this embodiment, the input unit 34 may have a function (function as an operation unit) of setting various parameters such as the frequency related to the OTA traffic analysis process, and of instructing the start or end of the OTA traffic analysis process.

[0081] The display unit 35 displays various information and screens related to the OTA traffic analysis process, such as a setting screen for OTA traffic analysis conditions (setting parameters) and a display screen for displaying PDU estimation results, under the display control of the above-mentioned display control unit 47. The display unit 35 may be configured with a touch panel or the like to enable input of setting parameters, commands, etc.

[0082] Next, the PDU estimation process operation in the OTA traffic analysis device 1 according to this embodiment will be described with reference to the flowchart shown in FIG.

[0083] In order to perform this PDU estimation process, the OTA traffic analysis device 1 is installed at a desired location within the observation area 6.

[0084] After being installed at a desired location, the OTA traffic analysis device 1 performs a pre-start setting (analysis condition setting) process in which the analysis condition setting unit 41 of the control unit 31 sets setting items (parameters) required to execute the PDU estimation process (step S1). The analysis condition setting process can be performed, for example, by displaying a setting screen on the display unit 35 and accepting input of setting values ​​from the input unit 34 by the user into setting fields for each setting item displayed on the setting screen.

[0085] Here, the analysis condition setting unit 41 accepts input (setting operation) of setting items such as frequency, data rate, received signal length (signal capture time), reception interval, maximum PDU size, minimum PDU size, minimum gap length between PDUs, and threshold angle (used when selecting components of the same communication from the direction of arrival) based on the protocol used for communication between the base station B1 and the wireless terminal A1 and the configuration of the PDU that matches the protocol specification, and performs processing to set each of the input items. The received signal length (signal capture time) and reception interval correspond to the reception time Trx and reception interval Tint in Fig. 3, respectively.

[0086] Next, the control unit 31 accepts a start operation of the traffic analysis process by the user, for example, at the input unit 34 (step S2). This start operation can be performed, for example, by pressing a "Start" button displayed on the above-mentioned setting screen.

[0087] When a predetermined start operation for the traffic analysis process is performed, the OTA traffic analysis device 1 controls the antenna device 10 and the blind signal estimation device 20 from the device control unit 31a of the data processing device 30 to receive a multi-wave mixed signal containing a mixture of multiple radio signals (step S3).

[0088] Here, the antenna control unit 42 of the device control unit 31a drives and controls the antenna device 10 so as to intermittently capture a multiple-wave mixed signal of the frequency band set by the analysis condition setting unit 41 at the received signal length (signal capture time) and reception interval set in step S2. Furthermore, the device control unit 31a drives and controls the blind signal estimation device 20 so as to perform signal processing of the captured signal in accordance with the intermittent capture of the multiple-wave mixed signal of the frequency band by the antenna device 10. By this drive control, in the blind signal estimation device 20, the received signal intermittently captured by the antenna device 10 is frequency-converted by the frequency conversion unit 21, and the received signal after the frequency conversion is subjected to signal processing in which the AD conversion unit 22 converts the received signal from an analog signal to a digital signal, and the signal is promptly input to the signal separation unit 23 after capture.

[0089] The signal separation unit 23 performs a process (see signal separation time Tp in FIG. 3) of separating a plurality of signal source components arriving from the surroundings at the point from the input signal (captured signal) for each signal source 110 (step S4), and inputs the signal source components of the separated signal (separated signal) to the arrival direction estimation processing unit 24 and the signal analysis unit 25. Next, the arrival direction estimation processing unit 24 and the signal analysis unit 25 perform a process (see separated signal time Ts≈reception time Trx in FIG. 3) of analyzing the input separated signal to estimate the arrival direction and signal strength of the separated signal (step S5).

[0090] The direction of arrival estimation processing unit 24 estimates the direction of arrival in the above step S5 by applying, for example, the MUSIC method, the beamforming method, or the like to the inputted separated signals (signal source components transmitted from any of the multiple signal sources 110) and estimates the direction of arrival for each of the separated signals. The direction of arrival estimation processing unit 24 outputs the estimation result of the direction of arrival of the signal source 110 to the data processing device 30. Also, in the above step S5, the signal analysis unit 25 calculates the signal strength for each of the inputted separated signals, and also performs analysis processing on other items, and outputs the calculated signal strength for each separated signal and the analysis results of the other items to the data processing device 30.

[0091] Specifically, when applying the MUSIC method, for example, the arrival direction estimation processing unit 24 generates a MUSIC angle spectrum of each signal source component input from the signal separation unit 23. The MUSIC angle spectrum is configured as a graph, for example, with the horizontal axis representing the angle and the vertical axis representing the signal level, which represents the arrival direction (angle) of an arriving signal in relation to its signal level.

[0092] Subsequently, the arrival direction estimation processing unit 24 reads the signal level peak on the vertical axis of the MUSIC angular spectrum, and estimates the angle on the horizontal axis corresponding to the peak as the arrival direction (angle) of the arrival signal having that angular spectrum.

[0093] On the other hand, when the beamforming method is applied, the arrival direction estimation processing unit 24 generates a beamforming angle spectrum of each signal source component input from the signal separation unit 23. The beamforming angle spectrum is also configured as a graph, for example, with the horizontal axis representing the angle and the vertical axis representing the signal level, which represents the arrival direction (angle) of the arriving signal in relation to its signal level.

[0094] As a result, the arrival direction estimation processing unit 24 reads the signal level peak on the vertical axis of the beamforming angular spectrum, and estimates the angle on the horizontal axis corresponding to the peak as the arrival direction (angle) of the arrival signal having that angular spectrum.

[0095] The separated signals separated in step S4 and the estimated results of the arrival direction and signal strength for each separated signal based on the analysis processing in step S5 are continuously recorded in a predetermined storage area of ​​the database 33 by the data control unit 31b (step S6).

[0096] In conjunction with this, the PDU estimation unit 43 performs a process of estimating the size of a PDU that includes the separated signals stored in step S6 as some of its components and is transmitted and received between the base station B1 and the wireless terminal A1, based on the separated signals stored in step S6 and the estimated results of the arrival direction and signal strength for each separated signal (step S7).

[0097] The PDU estimation process in step S7 can be performed, for example, as described above, by the procedure according to the timing chart shown in Fig. 5. Here, the PDU estimation unit 43 uses the estimated results of the arrival directions and signal strengths of the multiple separated signals stored corresponding to each capture time (see step S6) as indicators, and continuously performs a process of selecting, as components of the same communication, for each pair of separated signals that satisfy a preset condition before and after the capture time, i.e., the condition of the range of the threshold angle set in step S2 above, as components of the same communication, as the capture time passes.

[0098] In this process, the separated signals selected as components of the same communication (in the example of Figure 5, Sa and Sa', Sb and Sb', Sc and Sc') may appear in a mixture of various patterns for each pair, such as a first pattern in which they are not selected at a certain capture time but are selected at the next capture time, a pattern in which they continue to be selected for multiple capture times after a certain capture time (second pattern), and a pattern in which they are selected at a certain capture time but are no longer selected at the next capture time (third pattern).

[0099] Assuming that such patterns of separated signals (separated signal patterns) appear, for example, the separated signal of the first pattern described above can be inferred to be the separated signal of the head portion of the PDU to be estimated (estimated PDU). Also, the separated signals of the second and third patterns described above can be inferred to be the separated signals of the continuing portion (continuation portion) and the rear end portion of the estimated PDU, respectively.

[0100] An example of the correspondence relationship between the received signal, the separated signal pattern, and the estimated PDU is shown in Fig. 10. In Fig. 10, (a) shows the correspondence relationship when only a separated signal pattern that is not received at the timing next after the received signal is included, (b) shows the correspondence relationship when a separated signal pattern that is not received at the timing next after the received signal and two separated signal patterns that are not received at the timing next after the received signal are included, (c) shows the correspondence relationship when a separated signal pattern that is not received at the timing next after the received signal and a separated signal pattern that is not received four timings after the received signal are included, and (d) shows the correspondence relationship when a separated signal pattern that is not received at the timing next after the received signal and a separated signal pattern that is not received at the timing next after the received signal after two consecutive timings of not being received are included.

[0101] According to the correspondence relationship between the received signal, demultiplexed signal pattern, and estimated PDU shown in FIG. 10, as shown in (a) to (d) of FIG. 10, from a demultiplexed signal pattern that is no longer received at the next timing after it is received, it is possible to estimate (obtain an estimated PDU) the PDU that is the beginning of the demultiplexed signal and that continues from the received capture time to just before the start of the next capture time.

[0102] Furthermore, as shown in Figures 10(b) and (d), from a separated signal pattern that is no longer received at the timing after it was received, it is possible to obtain an estimated PDU that continues from its reception until just before the start of the two subsequent capture times.

[0103] In addition, as shown in FIG. 10(c), for a separated signal that is no longer received four capture times after its reception, it is possible to obtain an estimated PDU that continues until the start of the capture time four times after its reception.

[0104] The PDU estimation process using the relationship between the separated signal pattern and the estimated PDU shown in Fig. 10 will be described in detail with reference to Fig. 9. In the PDU estimation process in step S7 in Fig. 8, the PDU estimation unit 43 sequentially reads out the estimation results of the arrival direction and signal strength of the stored separated signals (see step S6), and performs a process of determining the pattern of the separated signals (separated signal pattern) for each set of separated signals selected as components of the same communication, that is, for each arrangement of separated signals for each signal source 110, according to the flowchart shown in Fig. 9.

[0105] Here, for the separated signals at each capture time for each signal source 110, for example for a certain signal source 110, the PDU estimation unit 43 determines that the point at which the separated signal is detected is the beginning of a PDU that can be estimated (estimated PDU) (step S61).

[0106] Furthermore, if the separated signal is still detected, the PDU estimation unit 43 determines, for example, that the estimated PDU is still continuing (step S62).

[0107] On the other hand, if the separated signal is not detected, the PDU estimation unit 43 determines that the end of the estimated PDU is reached at that point (step S63).

[0108] While repeatedly performing the processes from step S61 to step S63, the PDU estimation unit 43 sequentially constructs an estimated PDU from the separated signal of the signal transmitted from the signal source 110. During the process of constructing the estimated PDU, the PDU estimation unit 43 determines that it is the end of the PDU when the data length calculated from the elapsed time from the head of the PDU and the data rate reaches a preset maximum PDU size (step S64).

[0109] On the other hand, if the data length is found to be shorter than the preset PDU minimum size in step S64, the PDU estimation unit 43 extends the data to the PDU minimum size and adjusts the PDU start position and PDU end position (time) (step S65). To perform this process, the PDU estimation unit 43 is configured to determine whether only the start position, only the end position, or both the start and end positions are missed. Depending on the result of this determination, if only the start position is missed, the PDU estimation unit 43 advances the start position (time) by the amount of size extension, and if only the end position is missed, the end position (time) is delayed by the amount of size extension. If both the start position and the end position are missed, a process is performed to shift both the front and back by half the amount of size extension.

[0110] Furthermore, during the process of constructing an estimated PDU by repeating steps S61 to S63, if the PDU estimation unit 43 detects the next separation signal at an interval shorter than the predetermined minimum gap between PDUs from the end of the PDU, it determines that the point where the separation was detected is the beginning of the next PDU, and goes back to the previous estimated PDU and modifies it to a size appropriate for the minimum gap between PDUs (step S66).

[0111] As shown in FIG. 9, the PDU estimation unit 43 selects, for each group, separated signals that are selected as components of the same communication from the estimated results of the arrival direction and signal strength of the stored multiple separated signals (see step S6 in FIG. 8), and updates the estimated PDU by applying a separated signal pattern judgment process (see FIG. 10) to each separate separated signal in each group.

[0112] Through this process, in step S7 of Fig. 8, the PDU estimation unit 43 can finally estimate (obtain an estimated PDU) the pattern of PDUs transmitted by wireless signals from the signal source 110 for each component of the same communication, that is, for each signal source 110. In this manner, the PDU estimation unit 43 continues the PDU estimation process until an estimated PDU that matches the frequency, data rate, maximum PDU size, minimum PDU size, and minimum inter-PDU gap length set in step S1 of Fig. 8 is obtained.

[0113] As described above, the OTA traffic analysis device 1 of the first embodiment intermittently captures a multi-wave mixed signal that is a mixture of wireless signals transmitted and received between a base station B1 and a wireless terminal A1 in an OTA environment in which wireless communication is performed between a base station B1 and a plurality of wireless terminals A1, and analyzes wireless communication traffic based on separated signals separated for each signal source 110, which is a wireless terminal A1, from the received signal intermittently acquired in response to the capture.

[0114] The OTA traffic analysis device 1 of the first embodiment has a device control unit 31a that controls the signal capture time and reception interval of a multiple-wave mixed signal, a PDU estimation unit 43 that selects a separated signal separated after capture for each component of the same communication, estimates a signal pattern of the selected separated signal for each component of the same communication, and estimates a PDU to be transmitted and received by wireless communication for each component of the same communication based on the estimated signal pattern of the separated signal, an arrival direction estimation processing unit 24 that estimates the arrival direction of the separated signal, and a signal analysis unit 25 that estimates the signal strength of the separated signal, and the PDU estimation unit 43 has a configuration that selects a separated signal for each component of the same communication taking into account the arrival direction and signal strength of the separated signal, and estimates a PDU to be transmitted and received by wireless communication for each component of the same communication based on the signal pattern of the selected separated signal.

[0115] With this configuration, the OTA traffic analysis device 1 of the first embodiment can estimate the signal pattern of the separated signals of the components of the same communication separated from the intermittently received received signal, and then easily estimate the length and interval of the PDU for each component of the same communication from the signal pattern, making it possible to observe the number of wireless terminals and the communication volume of each wireless terminal via OTA without affecting the operation of the wireless communication system that uses a specific frequency.

[0116] In particular, in the OTA traffic analysis device 1 according to the first embodiment, the arrival direction estimation function and signal strength estimation function of the existing blind signal estimation device 20 are used in combination, and the estimated results of the arrival direction and signal strength of the separated signals are taken into account to estimate the signal pattern of the separated signals of the same communication components, and then the PDU is estimated. This makes it possible to improve the PDU estimation accuracy without complicating the configuration, compared to the case where the estimated results of the arrival direction and signal strength are not taken into account.

[0117] Moreover, the OTA traffic analysis device 1 according to the first embodiment further includes an analysis condition setting unit 41 that sets parameters related to the analysis of communication traffic. The analysis condition setting unit 41 sets the parameters as frequency, data rate, signal capture time, reception interval, maximum PDU size, minimum PDU size, and minimum gap length between PDUs. The device control unit 31a controls the capture of a multiple-wave mixed signal at the set signal capture time and reception interval. The PDU estimation unit 43 is configured to continue the PDU estimation process until an estimated PDU that matches the set frequency, data rate, maximum PDU size, minimum PDU size, and minimum gap length between PDUs is acquired.

[0118] With this configuration, the OTA traffic analysis device 1 of the first embodiment can easily estimate a PDU that matches the desired frequency, desired data rate and size (maximum PDU size, minimum PDU size, minimum gap length between PDUs), etc., by setting parameters using the analysis condition setting unit 41.

[0119] In addition, in the OTA traffic analysis device 1 according to the first embodiment, the analysis condition setting unit 41 further sets a threshold value for the arrival angle, and the PDU estimation unit 43 is configured to select, from among the separated signals at adjacent signal capture times, those whose arrival directions are within the range of the above threshold value as components of the same communication.

[0120] With this configuration, the OTA traffic analysis device 1 of the first embodiment can easily perform a process of selecting separated signals that are within the angle range of the threshold by setting a threshold for the arrival angle, for each component of the same communication, thereby speeding up the analysis process of communication traffic in an OTA environment.

[0121] Furthermore, in the OTA traffic analysis device 1 according to the first embodiment, the PDU estimation unit 43 determines whether the separated signal is the beginning of a PDU, a continuation of a PDU, or the end of a PDU, depending on whether the separated signal has been received, is continuing to be received, or has ceased to be received corresponding to the signal capture time, and estimates the length and interval of the PDU based on the result of that determination.

[0122] With this configuration, the OTA traffic analysis device 1 according to the first embodiment can simplify the process up to obtaining the PDU (estimated PDU) obtained as the estimation result, and can also shorten the processing time.

[0123] Moreover, the OTA traffic analysis method according to the first embodiment is for intermittently capturing a multi-wave mixed signal containing a mixture of wireless signals transmitted and received between a base station B1 and a plurality of wireless terminals A1 in an OTA environment in which wireless communication is performed between the base station B1 and a plurality of wireless terminals A1, and analyzing wireless communication traffic based on separated signals separated for each signal source 110, which is the wireless terminal A1, from the received signal intermittently acquired in response to the capture, and includes a step (S3) of controlling the signal capture time and reception interval of the multi-wave mixed signal, and a PDU estimation step (S7) of selecting the separated signals separated after capture for each component of the same communication, estimating the signal pattern of the selected separated signals for each component of the same communication, and estimating the PDU transmitted and received by wireless communication for each component of the same communication based on the estimated signal pattern of the separated signals, and in the PDU estimation step (S7), the separated signals are selected for each component of the same communication taking into account the arrival direction and signal strength of the separated signals, and the PDU transmitted and received by wireless communication for each component of the same communication is estimated based on the signal pattern of the selected separated signals.

[0124] With this configuration, the OTA traffic analysis method according to the first embodiment can estimate the signal pattern of the separated signals of the components of the same communication separated from the intermittently received received signal, and can easily estimate the length and interval of the PDU for each component of the same communication from the signal pattern, and can monitor the number of wireless terminals and the communication volume of each wireless terminal by OTA without affecting the operation of a wireless communication system using a specific frequency. In particular, according to the OTA traffic analysis method according to the first embodiment, the arrival direction estimation function and the signal strength estimation function of the existing blind signal estimation device 20 are used in combination, and the estimated results of the arrival direction and signal strength of the separated signals are taken into account to estimate the signal pattern of the separated signals of the components of the same communication, and then the PDU is estimated, so that the accuracy of PDU estimation can be improved without complicating the configuration compared to the case where the estimated results of the arrival direction and signal strength are not taken into account.

[0125] Second Embodiment A configuration of an OTA traffic analysis device 1A according to the second embodiment is shown in Fig. 11. As shown in Fig. 11, the OTA traffic analysis device 1A according to the second embodiment includes a PDU estimation unit 43A instead of the PDU estimation unit 43 in the data processing device 30 of the OTA traffic analysis device 1 according to the first embodiment. The PDU estimation unit 43 separates signals contained in an intermittently received received signal into components of the same communication (signal source 110) and estimates the length of a PDU based on the arrival direction and signal strength of the separated signals, whereas the PDU estimation unit 43A directly inputs the separated signals separated from the received signal by the signal separation unit 23 without using the arrival direction and signal strength, and estimates the length of a PDU based on the separated signal pattern.

[0126] The OTA traffic analysis device 1A according to the second embodiment has the same configuration as the OTA traffic analysis device 1 according to the first embodiment, except for a PDU estimation unit 43A. In Fig. 11, the same reference numerals are used to designate the same components as those of the OTA traffic analysis device 1 according to the first embodiment.

[0127] The PDU estimation process of the OTA traffic analysis device 1A according to the second embodiment will be described with reference to the flowchart shown in Fig. 12. In Fig. 12, the same processes as those in the PDU estimation process of the OTA traffic analysis device 1 according to the first embodiment shown in Fig. 8 are given the same step numbers, and detailed descriptions of the same processes will be omitted. Here, the process unique to the OTA traffic analysis device 1A according to the second embodiment will be mainly described.

[0128] In the OTA traffic analysis device 1A according to the second embodiment, the PDU estimation unit 43A first performs an analysis condition setting process (step S1), similarly to the OTA traffic analysis device 1 according to the first embodiment.

[0129] Thereafter, similarly to the OTA traffic analysis device 1 according to the first embodiment, the PDU estimation unit 43A receives an analysis start operation (step S2), drives the blind signal estimation device 20 to intermittently capture a multi-wave mixed signal in which multiple wireless signals are mixed (step S3), and executes a process of separating signal components for each signal source 110 from the captured signal by the signal separation unit 23 of the blind signal estimation device 20 (step S4).

[0130] The signal separator 23 inputs the separated signal source components (separated signals separated for each signal source 110) to the PDU estimation unit 43A of the data control unit 31b. Here, the PDU estimation unit 43A takes in the separated signals input from the signal separator 23, and performs a process of continuously storing the separated signals in a predetermined storage area of ​​the database 33 (step S6A).

[0131] The signal processing up to step S6A will be described with reference to Fig. 13. In the OTA traffic analysis device 1A according to the second embodiment, as shown in Fig. 13, a multi-wave mixed signal, which is a mixture of multiple radio signals transmitted and received between a base station B1 and a wireless terminal A1 in communication, is intermittently received by a blind signal estimation device 20 (see Fig. 13(a)).

[0132] In the OTA traffic analysis device 1A, the intermittently received multiple-wave mixed signal is subjected to signal processing by the frequency conversion unit 21 and the AD conversion unit 22 of the blind signal estimation device 20 (see FIG. 13(b)), and then separated for each signal source 110 by the signal separation unit 23, and is recorded in the database 33 as a separated signal (see FIG. 13(c)). In FIG. 13(c), the separated signals shown with the same shading indicate components of the same communication. Here, four types of shading are used to show the arrangement of separated signals S11, S12, S13, and S14 relating to four types of data communication. The arrangement of the separated signals S11, S12, S13, and S14 here constitutes an intermittent separated signal pattern of PDUs transmitted and received by four types of data communication. As a result, the PDU estimation unit 43A, like the PDU estimation unit 43 of the OTA traffic analysis device 1, is able to estimate (obtain estimated PDUs) the PDUs corresponding to each of the data A1, B1, C1, and D1 for each type of communication data based on the above-mentioned separated signal pattern.

[0133] That is, during the series of processes shown in FIG. 12, the PDU estimation unit 43A searches for the separation signal pattern of the stored separation signal in conjunction with the process of continuously recording the separation signal in step S6A, and performs a process of estimating the size of the PDU that includes the separation signal as a partial component based on the separation signal pattern (step S7A).

[0134] Timing charts of the signal processing in step S7A are shown in Fig. 13(d) and (e). In the OTA traffic analysis device 1A according to the second embodiment, as shown in Fig. 13(d), a process is performed to estimate PDUs corresponding to the data A1, B1, C1, and D1, respectively, from the demultiplexed signal patterns of the demultiplexed signals S11, S12, S13, and S14 (see Fig. 13(c)) generated in the previous process.

[0135] This PDU estimation process is executed by the PDU estimation unit 43A by applying the decision flow shown in Fig. 9 in light of the relationship between the received signal, separated signal, and estimated PDU shown in Fig. 10. According to this PDU estimation process, as shown in Fig. 13(e), it is possible to estimate PDUs corresponding to data A1, B1, C1, and D1 in the sections in which separated signals S11, S12, S13, and S14 shown in Fig. 13(c) continue, respectively.

[0136] As described above, the OTA traffic analysis device 1A according to the second embodiment has a device control unit 31a that controls the signal capture time and reception interval of a multi-wave mixed signal, and a PDU estimation unit 43A that selects separated signals separated after capture for each component of the same communication, estimates the signal pattern of the selected separated signals for each component of the same communication, and estimates the PDU transmitted and received by wireless communication for each component of the same communication based on the estimated signal pattern of the separated signal.

[0137] Here, unlike the PDU estimation unit 43 according to the first embodiment, the PDU estimation unit 43A has a configuration for estimating a separated signal pattern without referring to the arrival direction and signal strength of the separated signals, and further estimating a PDU from the separated signal pattern. With this configuration, the OTA traffic analysis device 1A according to the second embodiment does not need to perform the process of estimating the arrival direction of the separated signals by the arrival direction estimation processing unit 24 of the blind signal estimation device 20, and the process of estimating the signal strength of the separated signals by the signal analysis unit 25, and it is possible to reduce the processing load of the PDU estimation unit 43 and to alleviate the request for increased processing capacity. [Industrial Applicability]

[0138] As described above, the present invention has the effect of enabling efficient and highly accurate observation of OTA traffic from an intermittently received signal containing multiple waves without affecting a wireless communication system in communication, and is useful for OTA traffic analysis devices and OTA traffic analysis methods in general that are necessitated by intermittent reception of a signal containing multiple waves. [Explanation of symbols]

[0139] 1. 1A OTA traffic analyzer 6 Observation Area 10 Antenna device 20 Blind signal estimator 20a Receiving section 20b Analysis processing section 21 Frequency conversion section 22 AD conversion section 23 Signal separation section 24 Arrival direction estimation processing unit (arrival direction estimation means) 25 Signal analysis unit (signal strength estimation means) 30 Data processing device 31 Control Unit 31a Device control unit (capture control means) 31b Data control section 33 Database 34 Input section (setting means) 35 Display section 41 Analysis condition setting unit (setting means) 42 Antenna control section 43, 43A PDU estimation section (PDU estimation means) 47 Display control section 110 Signal source A1 Wireless Terminal

Claims

1. An OTA traffic analysis device (1, 1A) that, in an OTA environment in which wireless communication is performed between a base station (B1) and a plurality of wireless terminals (A1), intermittently captures a multi-wave mixed signal in which wireless signals transmitted and received between the base station and the wireless terminals are mixed, and analyzes communication traffic of the wireless communication based on a separated signal separated for each signal source (110) that is the wireless terminal from a received signal intermittently acquired in response to the capture, A capture control means (31a) for controlling a signal capture time and a reception interval of the multi-wave mixed signal; a PDU estimation means (43, 43A) for selecting the separated signals separated after capture for each signal arriving from the same signal source, estimating a signal pattern of the selected separated signals for each signal arriving from the same signal source, and estimating a protocol data unit (PDU) transmitted and received by the wireless communication for each signal arriving from the same signal source based on the estimated signal pattern of the separated signals; An OTA traffic analysis device comprising:

2. The method further comprises setting means (41) for setting parameters related to the analysis of the communication traffic, the setting means sets, as the parameters, a frequency, a data rate, the signal capture time, the reception interval, a maximum PDU size, a minimum PDU size, and a minimum inter-PDU gap length; the capture control means controls so that the capture is performed at the set signal capture time and reception interval; 2. The OTA traffic analysis device according to claim 1, wherein the PDU estimation means continues the PDU estimation process until an estimated PDU that matches a set frequency, data rate, maximum PDU size, minimum PDU size, and minimum inter-PDU gap length is obtained.

3. an arrival direction estimation means (24) for estimating the arrival direction of the separated signals; and a signal strength estimation means (25) for estimating the signal strength of the separated signals, The PDU estimation means selects the demultiplexed signals for each signal arriving from the same signal source, taking into consideration the arrival direction and signal strength of the demultiplexed signals, and estimates a PDU to be transmitted and received by the wireless communication for each signal arriving from the same signal source, based on a signal pattern of the selected demultiplexed signals.

3. The OTA traffic analysis device according to claim 2 .

4. The setting means further sets a threshold value for an arrival angle, The OTA traffic analysis device according to claim 3, characterized in that the PDU estimation means selects, from among the separated signals at adjacent signal capture times, those separated signals whose arrival directions are within the range of the threshold as signals arriving from the same signal source.

5. the PDU estimation means determines whether the separated signal is the beginning of the PDU, a continuation of the PDU, or a tail of the PDU, depending on whether the separated signal has been received, is being received, or has ceased to be received, corresponding to the signal capture time; 4. The OTA traffic analysis device according to claim 1, further comprising: a step of estimating a length and an interval of the PDU based on a result of the judgment.

6. An OTA traffic analysis method for analyzing communication traffic of the wireless communication based on a separated signal obtained by separating a received signal intermittently acquired in response to the capture for each signal source (110) of the wireless terminal, in an OTA environment in which wireless communication is performed between a base station (B1) and a plurality of wireless terminals (A1), comprising: A capture control step (S3) of controlling a signal capture time and a reception interval of the multi-wave mixed signal; selecting the separated signals separated after capture for each signal coming from the same signal source, and estimating a signal pattern of the selected separated signals for each signal coming from the same signal source (S61 to S66); a PDU estimation step (S7) of estimating a protocol data unit (PDU) transmitted and received by the wireless communication for each signal arriving from the same signal source based on the estimated signal pattern of the separated signal; 13. A method for analyzing OTA traffic, comprising:

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