Wireless terminal testing device and method for displaying timing deviation

Abstract

To provide a wireless terminal testing device that makes it easy to determine the timing difference of uplink signals and to easily perform timing adjustment of uplink signals. [Solution] The system includes a delay addition unit 12 that adds a signal propagation delay amount calculated from the satellite and the position information of the satellite to the uplink signal from the UE100 and outputs it; a timing generation unit 13 that generates a downlink signal in synchronization with the Subframe timing and synchronizes with the UE100; a power measurement unit 14 that measures the power of the uplink signal received from the UE100 at predetermined time intervals; a reception processing unit 15 that performs reception processing of the received uplink signal; a heatmap generation unit 16 that displays the power measurement values ​​measured by the power measurement unit 14 as a heatmap arranged in chronological order on a display unit 18; and a timing deviation detection unit 17 that overlays the position of the 3GPP standard NPRACH on the heatmap and displays it surrounded by a frame.

Description

Technical Field

[0001] The present invention relates to a wireless terminal test apparatus that simulates a base station of a wireless communication system to test a wireless terminal.

Background Art

[0002] When developing a wireless terminal that uses wireless communication for network connection such as an IoT (Internet of Things) terminal, it is necessary to test whether the developed wireless terminal can communicate normally. For this reason, a test apparatus that operates as a pseudo base station that simulates the functions of an actual base station is connected to the wireless terminal to be tested, communication is performed between the test apparatus and the wireless terminal, and a test is performed to confirm the content of this communication.

[0003] NB-IoT (NarrowBand Internet of Things) has been standardized as a communication means for IoT terminals. In addition, NTN (Non-Terrestrial Network), a non-terrestrial network using satellites that can be used with NB-IoT, has also been defined.

[0004] In Patent Document 1, it is described that in NTN, uplink synchronization is executed by appropriately setting TA (Timing Advance) between an airborne base station and a terminal.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When simulating communication between NB-IoT wireless terminals via NTN, a satellite is inserted between the base station and the wireless terminal, resulting in a larger propagation delay than during ground-based communication.

[0007] Since the base station lacks a means to accurately measure the propagation delay between the wireless terminal and the satellite, it waits for the uplink signal based on the propagation delay calculated from the positional information of the wireless terminal and the satellite.

[0008] The uplink signal timing search range is specified as within ±100μs, which is much narrower than the propagation delay, making timing synchronization difficult.

[0009] Therefore, the present invention aims to provide a wireless terminal testing device that makes it easy to determine the timing difference of the uplink signal and to easily perform timing adjustment of the uplink signal. [Means for solving the problem]

[0010] The wireless terminal testing apparatus of the present invention is a wireless terminal testing apparatus (1) that performs testing of a wireless terminal (100) by simulating communication with the wireless terminal via a satellite, and displays on a display unit (18) the difference between the period when the power of the uplink signal from the wireless terminal is high and the period when the timing position of NPRACH (Narrowband Physical Random Access Channel) is high.

[0011] This configuration displays the time difference between the period when the uplink signal power is high and the timing position of the NPRACH. Therefore, the timing difference of the uplink signal can be easily identified, and the uplink signal timing can be easily adjusted.

[0012] Furthermore, the wireless terminal testing apparatus of the present invention displays the period of the NPRACH timing position on a heat map that arranges the power values ​​of the uplink signal at predetermined time intervals in a time series, using a border.

[0013] This configuration displays the power values ​​of the uplink signal at predetermined intervals in a time-series heatmap, with the timing positions of the NPRACH signal indicated by a border. This makes it easy to see the difference in the timing of the uplink signal and to easily synchronize the uplink signal timing.

[0014] Furthermore, the wireless terminal testing apparatus of the present invention displays the heat map differently for periods when the power of the uplink signal is high compared to other periods.

[0015] This configuration displays periods of high uplink signal power in the heatmap in a different way than other periods. Therefore, it is easy to identify differences in uplink signal timing and easily adjust the uplink signal timing.

[0016] Furthermore, the present invention relates to a timing deviation display method for a wireless terminal test device (1) that simulates communication between a wireless terminal (100) and a satellite to perform testing of the wireless terminal, and comprises the steps of: displaying a heat map on a display unit (18) in which the power values ​​of the uplink signal from the wireless terminal at predetermined time intervals are arranged in chronological order; and displaying the period of the timing position of NPRACH on the heat map with a frame.

[0017] This configuration displays the power values ​​of the uplink signal at predetermined intervals in a time-series heatmap, with the timing positions of the NPRACH signal indicated by a border. This makes it easy to see the difference in the timing of the uplink signal and to easily synchronize the uplink signal timing. [Effects of the Invention]

[0018] The present invention provides a wireless terminal testing device that makes it easy to determine the timing difference of the uplink signal and to easily perform timing adjustment of the uplink signal. [Brief explanation of the drawing]

[0019] [Figure 1] FIG. 1 is a block diagram of a wireless terminal test apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an example of a heat map and the timing position of NPRACH when the timings of the wireless terminal test apparatus according to an embodiment of the present invention match. [Figure 3] FIG. 3 is a diagram showing an example of a heat map and the timing position of NPRACH when the timings of the wireless terminal test apparatus according to an embodiment of the present invention do not match. [Figure 4] FIG. 4 is a flowchart for explaining the procedure of the timing deviation display process of the wireless terminal test apparatus according to an embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

[0020] Hereinafter, a wireless terminal test apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0021] In FIG. 1, a wireless terminal test apparatus 1 according to an embodiment of the present invention is connected to a UE (User Equipment) 100 as a wireless terminal via a coaxial cable or the like, and performs a measurement test by transmitting and receiving RF (radio frequency) signals with the UE 100 while simulating a base station.

[0022] The wireless terminal test apparatus 1 includes a scenario processing unit 11, a delay addition unit 12, a timing generation unit 13, a power measurement unit 14, a reception processing unit 15, a heat map generation unit 16, a timing deviation detection unit 17, and a display unit 18.

[0023] The scenario processing unit 11 creates a scenario for simulating a base station based on settings for simulating a base station input from a user, and simulates the base station based on the scenario. When performing a test of communication via NTN, the position information of the satellite and the UE 100 is set in the scenario.

[0024] The delay addition unit 12 adds a signal propagation delay amount calculated from the satellite and UE100 position information set in the scenario to the uplink signal from UE100 and outputs it. The delay amount is approximately 500 msec at most.

[0025] The timing generation unit 13 generates subframe timings with a period of 1 msec, and generates downlink signals synchronized with these to synchronize with the UE100, enabling the receiving processing unit 15 to receive uplink signals.

[0026] The power measurement unit 14 measures the power of the uplink signal received from the UE100. For example, the power measurement unit 14 measures the power of the uplink signal in 0.1ms units and outputs the result.

[0027] The receiving processing unit 15 performs receiving processing such as timing synchronization processing and demodulation processing of the received uplink signal, and outputs the processed signal and timing information of the received signal.

[0028] The heatmap generation unit 16 displays the power measurement values ​​measured by the power measurement unit 14 as a heatmap arranged in chronological order on the display unit 18, based on the outputs of the power measurement unit 14 and the receiving processing unit 15, and displays periods with high power measurement values ​​in a different color from other periods.

[0029] The timing deviation detection unit 17, based on the output of the power measurement unit 14 and the reception processing unit 15, uses timing information of the received signal to determine the position of the NPRACH (Narrowband Physical Random Access Channel) according to the 3GPP (3rd Generation Partnership Project) standard. The NPRACH is then overlaid on the heatmap generated and displayed by the heatmap generation unit 16, and displayed surrounded by a frame of a different color and shape from the other frames. The start position of the NPRACH is determined by the transmission timing of the downlink signal, and its end position is determined by the 3GPP standard.

[0030] The display unit 18 consists of an image display device such as a liquid crystal display and displays images generated by the heat map generation unit 16, the timing deviation detection unit 17, etc.

[0031] Here, the wireless terminal test device 1 is composed of a computer device (not shown) equipped with a communication module for communicating with the UE100. This computer device includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), a storage device such as a hard disk drive, input / output ports, and a touch panel (all not shown).

[0032] The ROM and hard disk drive of this computer device store programs that enable the computer device to function as a wireless terminal test device 1. In other words, the CPU executes the programs stored in the ROM using the RAM as a working area, thereby enabling the computer device to function as a wireless terminal test device 1.

[0033] Thus, in this embodiment, the scenario processing unit 11, the heatmap generation unit 16, and the timing deviation detection unit 17 are configured by a CPU, while the delay addition unit 12, the timing generation unit 13, the power measurement unit 14, and the reception processing unit 15 are configured by a communication module.

[0034] In the wireless terminal test apparatus 1 with this configuration, the heat map generation unit 16 and the timing deviation detection unit 17 display, for example, a heat map and a frame for the timing position of NPRACH on the display unit 18, as shown in Figure 2.

[0035] In Figure 2, the "System Frame Number" column in the "Timing information" column shows the number of the wireless frame, and the "Sub Frame Number" column shows the number of the subframe obtained by dividing one frame into 10 parts.

[0036] The "Timing Error" column in the "NPRACH reception result" column shows the amount of discrepancy between the NPRACH timing position border and the power measurement values ​​in the heatmap over large periods; the "Resource Index" column shows an index indicating the range of available coverage; and the "Number of Current Repetition" column shows the current number of repetitions.

[0037] The "Uplink heatmap" on the right side of the diagram displays the power measurements of the uplink signal at 0.1ms intervals in a time-series heatmap. Periods with high power measurements (periods where the value is 2.3) are displayed in a different color compared to other periods (periods where the value is negative).

[0038] In the heatmap, the time periods corresponding to the timing positions of NPRACH are enclosed by a thick border, different from the other borders, as shown in Figure A. The border in Figure A may be a different color from the other borders.

[0039] In Figure 2, the period of high power measurement coincides with the timing of NPRACH, indicating successful reception of NPRACH.

[0040] Figure 3 shows a case where the period of high power measurement does not coincide with the timing position of NPRACH.

[0041] In Figure 3, the periods indicated by B and C are considered to be periods in which the power measurement values ​​are not close to those of adjacent periods, and where the power measurement values ​​are changing from small to large or large to small. Therefore, the area displayed with a different color is narrowed according to the ratio of the power measurement values ​​to the power measurement values ​​during periods with large power measurement values.

[0042] In the example shown in Figure 3, the discrepancy between the period of high power measurement and the timing position of NPRACH is approximately +0.28 ms (approximately 0.28 ms behind the timing specified by the 3GPP standard).

[0043] As shown in Figure 3, if there is a discrepancy between the period of high power measurement values ​​and the timing position of NPRACH, for example, the TA setting value of UE100 can be changed to adjust the discrepancy between the period of high power measurement values ​​and the timing position of NPRACH to within ±1 grid unit.

[0044] The timing lag display process by the wireless terminal test device 1 configured as described above according to this embodiment will be explained with reference to Figure 4. The timing lag display process described below is started when the user selects to start communication with UE100.

[0045] In step S1, the timing generation unit 13 performs the process of transmitting a downlink signal as communication with the UE 100. After executing the process in step S1, the delay addition unit 12 performs the process in step S2.

[0046] In step S2, the delay addition unit 12 calculates the delay amount from the satellite and UE100 position information set in the scenario, adds the delay amount to the received uplink signal, and outputs it to the power measurement unit 14 and the receiving processing unit 15. After executing the process in step S2, the power measurement unit 14 executes the process in step S3, and the receiving processing unit 15 executes the process in step S4.

[0047] In step S3, the power measurement unit 14 measures the power of the uplink signal at predetermined time intervals and outputs the result. After executing the process in step S3, the timing deviation detection unit 17 executes the process in step S5.

[0048] In step S4, the receiving processing unit 15 performs the receiving processing of the uplink signal. After performing the processing in step S4, the heatmap generation unit 16 performs the processing in step S6.

[0049] In step S5, the timing deviation detection unit 17 calculates the position of the NPRACH according to the 3GPP standard based on the outputs of the power measurement unit 14 and the receiving processing unit 15. After executing the process in step S5, the timing deviation detection unit 17 executes the process in step S7.

[0050] In step S6, the heatmap generation unit 16 generates a heatmap in which power measurement values ​​at predetermined time intervals are arranged in chronological order based on the outputs of the power measurement unit 14 and the receiving processing unit 15. After executing the process in step S6, the heatmap generation unit 16 executes the process in step S7.

[0051] In step S7, the heatmap generation unit 16 displays the heatmap on the display unit 18, displaying periods with high power measurement values ​​in a different color from other periods, and the timing deviation detection unit 17 overlays a frame indicating the position of NPRACH according to the 3GPP standard onto the heatmap. After executing the process in step S7, the heatmap generation unit 16 and the timing deviation detection unit 17 terminate the timing deviation display process.

[0052] As described above, in the embodiment, the wireless terminal test device 1 displays a heat map of the power measurement values ​​of the uplink signal at predetermined time intervals, changing the display for periods when the power measurement values ​​are high, and overlays a frame indicating the position of NPRACH according to the 3GPP standard on this heat map.

[0053] This makes it easy to determine the timing difference of the uplink signals and to easily synchronize the timing of the uplink signals.

[0054] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of Symbols]

[0055] 1. Wireless terminal testing equipment 11 Scenario Processing Unit 12 Delay Addition Section 13 Timing generation unit 14 Power Measurement Section 15 Receiving Processing Unit 16 Heatmap generation section 17 Timing deviation detection unit 18 Display 100 UE (Wireless Terminal)

Claims

1. A wireless terminal test device (1) that simulates communication between a wireless terminal (100) and a satellite to perform a test of the wireless terminal, A wireless terminal test apparatus that displays on a display unit (18) the difference between the period during which the power of the uplink signal from the wireless terminal is high and the period during which the timing position of NPRACH is high.

2. The wireless terminal testing apparatus according to claim 1, wherein the period of the timing position of NPRACH is displayed with a border on a heat map obtained by arranging the power values ​​of the uplink signal at predetermined time intervals in a time series.

3. The wireless terminal testing apparatus according to claim 2, wherein the heat map displays differently for periods when the power of the uplink signal is high and for other periods.

4. A method for displaying timing deviations in a wireless terminal test device (1) that simulates communication between a wireless terminal (100) and a satellite to test the wireless terminal, The steps include: displaying a heat map on the display unit (18) showing the power values ​​of the uplink signal from the wireless terminal at predetermined time intervals arranged in chronological order; A timing deviation display method comprising the step of displaying the period of the timing position of NPRACH on the heat map with a border.

Images