CN101841826B - Method for testing automatic frequency control (AFC) capability of terminal and terminal testing device - Google Patents

Abstract

The invention discloses a terminal testing device and a method for testing terminal AFC by using the terminal testing device. The terminal testing device includes: an AFC test control module, which is used to configure the frequency information of the downlink signal, so that the frequency of the downlink signal changes with time. Offset; signal transceiver processing module, used to perform frequency offset processing on the downlink signal according to the frequency information of the configured downlink signal and send it to the terminal under test, and receive the uplink signal sent by the terminal under test; AFC test result output module , for outputting the curve of the frequency of the downlink signal and the curve of the AFC of the terminal under test, and the synchronization relationship between the two curves according to the frequency of the configured downlink signal and the frequency of the received uplink signal. By adopting the invention, the test result can accurately reflect the AFC capability of the terminal, and the fairness and objectivity of the test can be improved.

Description

A terminal AFC test method and terminal test equipment

technical field

The present invention relates to the communication field, in particular to a terminal AFC testing method and terminal testing equipment.

Background technique

High-speed scene coverage is the main topic of cellular mobile network coverage at present. In high-speed scenes, the frequency of the downlink signal received by the terminal is time-varying, and changes with the relative position of the terminal and the base station. When the position of the terminal relative to the base station changes rapidly during the process of receiving the downlink signal, the downlink signal received by the terminal in a short period of time will have a large frequency hop, and the signal with the frequency hop needs to be demodulated. As shown in Figure 1, when the terminal passes directly below the base station while moving with the vehicle, the frequency of the downlink signal jumps from F0+*fd to F0-*fd, that is, it jumps twice the Doppler frequency shift *fd.

For the terminal, its receiving frequency must always track the base station’s transmission frequency in order to correctly demodulate the received downlink signal. The process of tracking the base station’s transmission frequency is defined as AFC (automatic frequency control), that is, automatic frequency control. The AFC tracking capability of the terminal, especially the AFC tracking rate, will directly affect its demodulation capability in high-speed scenarios. If the AFC tracking rate is slow, it will directly cause long-term burst errors when the terminal passes the base station. Therefore, the test of terminal AFC is an important basis for evaluating terminal performance.

The current existing terminal AFC test method is to use the terminal's own tools to measure and draw the AFC curve. As shown in Figure 2, the downlink signal sent by the base station is simulated as a frequency hopping signal in a high-speed scenario through the channel emulator, so that the frequency change of the downlink signal received by the terminal is shown in Figure 3. Since the frequency of the signal received by the terminal changes, the terminal will start the AFC processing process, and the AFC curve of the terminal can be obtained through the monitoring tool of the terminal, which only records the frequency change of the downlink signal tracked by the terminal.

It can be seen that the AFC curve drawn by the terminal alone cannot reflect the time delay between the signal tracked by the terminal and the actual signal, so the AFC tracking rate of the terminal cannot be accurately obtained (AFC tracking rate = tracking frequency span / Tracking time, it can be seen that the AFC tracking rate is related to the tracking delay), and the AFC tracking rate is an important indicator for measurement. As shown in Figure 4, the top signal sequence is the signal sequence simulated by the channel emulator, and the following signal sequences are the AFC curves drawn by Terminal 1 and Terminal 2 respectively. It can be seen that although Terminal 1 and Terminal 2 draw The AFC curves of the AFC curves show that the signal frequency variation law is basically the same, but the AFC curve of terminal 1 is relatively synchronized with the signal sequence simulated by the channel emulator in time, which means that the AFC tracking rate of terminal 1 is better than that of terminal 2. In this way, terminal 1 1 will have a lower bit error rate than Terminal 2 in high-speed scenarios. However, the existing terminal AFC test method cannot reflect the synchronization between the terminal AFC and the signal sequence simulated by the channel emulator, so the AFC tracking rate cannot be obtained, and the test results cannot accurately reflect the terminal AFC capability.

In addition, it is difficult to guarantee the fairness and objectivity of the test by drawing the AFC curve through the terminal's built-in monitoring tool; in addition, the existing terminal AFC test technology needs to use a channel emulator for signal simulation, and the device connection is complicated.

Contents of the invention

Embodiments of the present invention provide a terminal AFC testing method and terminal testing equipment to solve the problems in the prior art that the AFC tracking delay cannot be obtained according to the AFC curve drawn by the terminal and the fairness and objectivity of the test are poor.

The terminal testing equipment provided by the embodiment of the present invention includes:

The AFC test control module is used to configure the frequency information of the downlink signal, so that the frequency of the downlink signal is shifted with time;

The signal transceiving processing module is used to perform frequency offset processing on the downlink signal according to the frequency information of the configured downlink signal and send it to the terminal under test, and receive the uplink signal sent by the terminal under test;

The AFC test result output module is configured to output the curve of the frequency of the downlink signal and the AFC curve of the terminal under test, and the synchronization relationship between the two curves according to the frequency of the configured downlink signal and the frequency of the received uplink signal.

The method for testing the terminal AFC provided by the embodiment of the present invention using the above-mentioned terminal testing equipment includes:

After the terminal testing device sends the downlink signal processed by the frequency offset to the terminal under test, it receives the uplink signal sent by the terminal under test;

The terminal testing equipment outputs the frequency curve of the downlink signal, the AFC curve of the terminal under test, and the synchronization relationship between the two curves according to the frequency of the transmitted downlink signal and the frequency of the received uplink signal.

In the above-mentioned embodiments of the present invention, the terminal test equipment performs offset processing on the downlink signal sent to the terminal under test and then sends it to the terminal under test, and then according to the uplink signal received by the terminal device from the terminal under test and the terminal test The frequency offset processing of the downlink signal sent by the device to the terminal under test, the curve of the output downlink signal frequency and the AFC curve of the terminal under test, and the synchronization relationship between the two curves, so that, on the one hand, the curve output by the terminal test device The synchronization relationship can accurately obtain the terminal AFC tracking delay, and then accurately calculate the AFC tracking rate, so as to accurately and comprehensively test the AFC capability of the terminal under test. On the other hand, the terminal AFC curve output by the terminal test equipment also improves Fairness and objectivity of testing.

Description of drawings

FIG. 1 is a schematic diagram of a frequency offset of a downlink signal received by a terminal in a high-speed scenario;

FIG. 2 is a schematic diagram of a terminal AFC test platform in the prior art;

Fig. 3 is a schematic diagram of the frequency change of the downlink signal output by the channel emulator in Fig. 2;

FIG. 4 is a schematic diagram of a terminal AFC curve obtained by testing in the prior art;

FIG. 5 is one of the structural schematic diagrams of the terminal testing equipment in the embodiment of the present invention;

FIG. 6 is the second structural schematic diagram of the terminal testing equipment in the embodiment of the present invention.

Detailed ways

In the embodiment of the present invention, the ACF test of the terminal is performed through the terminal test equipment. The process of using the terminal test equipment to perform the terminal AFC test may include:

The terminal test equipment sends the downlink signal processed by the terminal test equipment to the terminal under test, and then receives the uplink signal sent by the terminal under test, and then according to the frequency of the downlink signal sent by the terminal test equipment and the received uplink signal The frequency of the signal, output the frequency curve of the downlink signal sent by the terminal testing equipment and the AFC curve of the terminal under test, and the synchronization relationship between these two curves in time, as the AFC test result of the terminal under test.

Since the frequency of the downlink signal sent by the terminal test equipment is the downlink signal after the terminal test equipment performs frequency offset processing on the downlink signal of the signal source (such as a base station), for example, by simulating the signal frequency offset in the high-speed scene shown in Figure 1 The shift can make the frequency of the downlink signal change according to a certain rule, and this signal frequency change is preset by the terminal test equipment, so it is known to the terminal test equipment; The frequency of the received downlink signal remains consistent or basically consistent, that is, the downlink AFC curve of the terminal can be drawn by measuring the frequency change of the uplink signal of the terminal under test. By measuring the frequency of the uplink signal sent by the terminal, the curve of the downlink signal frequency and the downlink AFC curve of the terminal can be drawn. By comparison, the synchronization of the two curves in time can be seen, and the frequency of the downlink signal and the measured The synchronization relationship of the AFC of the terminal, so that the AFC tracking rate of the terminal under test can be accurately calculated, and then the performance of the terminal can be evaluated.

It can be seen that the AFC of the terminal under test can be tested through the terminal test equipment. Compared with the prior art, the application of equipment such as channel emulators and attenuators is saved, thereby simplifying the complexity of equipment connection and The complexity of building a test environment reduces the cost of testing and is easy to implement. In addition, the terminal under test does not need to bring its own monitoring tool to draw the AFC curve, but is uniformly drawn or output by the terminal test equipment. The terminal under test only needs to report the uplink signal in a conventional way, so that on the one hand, the fairness of terminal testing can be improved And objectivity, on the other hand, can also reduce the requirements of AFC testing on the terminal.

The terminal testing equipment provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 5 , it is a schematic structural diagram of a terminal testing device 1 in an embodiment of the present invention. The terminal test equipment may include: an AFC test control module 51 , a signal sending and receiving processing module 52 and an AFC test result output module 53 . in:

The AFC test control module 51 is used to configure the frequency information of the downlink signal, the frequency information of the downlink signal of the configuration can make the frequency of the downlink signal of the signal source offset with time, and notify the frequency information of the configured downlink signal to the signal transceiver A processing module 52 and an AFC test result output module 53 . The frequency information of the configured downlink signal can be the preset frequency change rule information, such as the frequency change rule for simulating the Doppler spectrum shift in the high-speed scene shown in Figure 1; it can also be based on the preset frequency change The frequency of the downlink signal configured regularly;

The signal transceiving processing module 52 is used for performing frequency offset processing on the downlink signal according to the frequency information of the downlink signal configured by the AFC test control module 51 and sending it to the terminal under test, and receiving the uplink signal sent by the terminal under test;

The AFC test result output module 53 is configured to output the frequency curve of the downlink signal and the AFC of the terminal under test according to the downlink signal frequency information configured by the AFC test control module 51 and the frequency of the uplink signal of the terminal under test received by the signal transceiving processing module 52 The curve, and the synchronous relationship between the two, are used as the test result of the AFC of the terminal under test. The output curve takes the time when the downlink signal starts to be sent as the starting point of time. It can include two curves, one is the curve of the frequency of the downlink signal over time, and the other is the terminal AFC curve. In this way, it can be seen from the output curve that the two are in time. The synchronization relationship, and can further calculate the AFC tracking rate of the terminal under test according to the synchronization relationship. For example, the curves output by the AFC test result output module 53 are respectively the downlink signal frequency curve of the channel emulator as shown in Figure 4 and the AFC curve of the terminal 2. According to the comparison, it can be determined that the two curves have a time difference Δt. The AFC tracking rate of the terminal 2 can be obtained by combining the obtained Δt with the counted number of error blocks (the AFC tracking rate can be obtained by using an existing calculation method).

The AFC test result output module 53 may further output the AFC tracking rate calculated according to the above method as a test result. It can be seen that since the AFC test result output module can draw the synchronization relationship between the downlink signal frequency curve and the terminal AFC curve, the calculation accuracy of the terminal AFC tracking rate can be improved according to the synchronization relationship.

The AFC test result output module 53 can output the test results to the display module of the terminal test device for screen display, and can also output to other external devices, such as printing devices, so as to draw the test results.

The AFC test control module 51 can also control the start and end of the terminal AFC test process. After the AFC test control module 51 starts the test process, the AFC test control module 51 can notify the signal transceiver processing module 52 and the AFC test result output module 53 of the frequency information of the configured downlink signal; when the AFC test control module 51 ends the test process , the signal transceiving processing module 52 may be notified to stop the signal transceiving processing operation.

The AFC test control module 51 can also configure the SNR of the downlink signal, and notify the signal transceiving processing module 52 of the configured SNR; the signal transceiving processing module 52 can perform baseband processing on the downlink signal according to the configuration information. Usually, in the process of testing the terminal, it is necessary to test the performance of the terminal in various channels. Since the signal-to-noise ratios of various channels are not necessarily the same, other devices are usually used to set the signal-to-noise ratio in the prior art. However, in this embodiment In , the signal-to-noise ratio is set through parameter configuration, which can simplify the setting operation of the signal-to-noise ratio and improve the flexibility of setting.

The signal transceiving processing module 52 can perform frequency offset processing during the baseband processing of the downlink signal, and then modulate the baseband processed signal into a radio frequency signal for transmission. In this way, the radio frequency processing process can be implemented in a conventional manner without modification.

The signal transceiving processing module 52 can be realized by the following units:

The baseband signal processing unit 521 is used to perform baseband processing on the downlink signal of the signal source. During the baseband processing of the downlink signal, the transmission frequency of the downlink signal is set according to the configured signal frequency information, so as to realize the frequency offset of the downlink signal deal with. For example, according to the downlink signal frequency change rule in the high-speed scenario shown in FIG. 1, the downlink signal frequency changing with time as shown in FIG. 3 is obtained;

A radio frequency signal processing unit 522, configured to modulate the downlink signal processed by the baseband signal processing unit 521 into a downlink radio frequency signal and send it, and receive an uplink radio frequency signal sent by the terminal under test;

The signal frequency measurement unit 523 is configured to measure the frequency of the uplink radio frequency signal received by the radio frequency signal processing unit 522 from the terminal under test, and notify the AFC test result output module 53 . The signal frequency measurement unit 523 can measure the signal frequency through an existing signal processing method, such as using a CZ device for measurement.

During the baseband processing, the baseband signal processing unit 521 can make the processed signal conform to the regulations by adding an AWGN (Additive White Gaussian Noise) signal to the downlink signal according to the set signal-to-noise ratio parameter. signal-to-noise ratio requirements.

The terminal testing equipment can also include a parameter setting module 54, which can provide the user with a test parameter setting interface, through which the user can set the frequency offset parameter and the frequency hopping period parameter of the downlink signal. Frequency change rules can be formulated through these two parameters. For example, for the frequency change rule in the high-speed scenario shown in Figure 1, the frequency offset parameter can be set to *fd, and the frequency hopping period can be set to t, and the frequency change curve shown in Figure 3 can be obtained. The signal-to-noise ratio parameter can also be set through the test parameter setting interface.

These test parameters can be configured to the AFC test control module 51 . The AFC test control module 51 can notify the signal transceiving processing module 52 of the frequency offset parameter and the frequency hopping cycle parameter when the test starts, so that it can set the frequency of the downlink signal according to the parameter, further, the signal can also be The noise ratio parameter is notified to the signal transceiving processing module 52, so that the module carries out baseband processing according to these parameters; the AFC test control module 51 can also notify the AFC test result output module 53 of the frequency offset parameter and the frequency hopping cycle parameter, In order to make the module draw the frequency change curve of the downlink signal according to these parameters.

By changing the connection relationship among the modules of the terminal testing equipment 1, the terminal testing equipment 2 as shown in FIG. 6 can be obtained.

Each functional module in the terminal test equipment 2 is identical or substantially identical to the corresponding functional modules in the terminal test equipment 1, the difference is that the signal frequency measurement unit 523 directly notifies the measured signal frequency to the AFC test result output module 53, so that The AFC test result output module 53 draws an AFC curve of the terminal under test according to the signal frequency.

It should be noted that the terminal test equipment provided in the embodiment of the present invention may be an independent terminal test equipment specially used for testing terminal AFC curves, or may be obtained by improving existing terminal test equipment. When the terminal test equipment of the embodiment of the present invention is improved on the basis of the existing terminal test equipment, functional modules such as AFC test control and ACF test result output need to be added, and some conventional processing functions, such as baseband signal processing function and radio frequency Signal processing functions, etc., can be realized by relying on the processing modules of the original test equipment or further improvement.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. A terminal testing device, characterized in that, comprising: The automatic frequency control AFC test control module is used to configure the frequency information of the downlink signal, so that the frequency of the downlink signal shifts with time; The signal transceiving processing module is used to perform frequency offset processing on the downlink signal according to the frequency information of the configured downlink signal and send it to the terminal under test, and receive the uplink signal sent by the terminal under test; The AFC test result output module is configured to output the curve of the frequency of the downlink signal and the AFC curve of the terminal under test, and the synchronization relationship between the two curves according to the frequency of the configured downlink signal and the frequency of the received uplink signal. 2. The terminal testing device according to claim 1, wherein the signal transceiving processing module includes: The baseband signal processing unit is used to perform frequency offset processing on the downlink signal according to the configured signal frequency information during the baseband processing of the downlink signal; A radio frequency signal processing unit, configured to modulate the downlink signal processed by the baseband signal processing unit into a downlink radio frequency signal for transmission, and receive an uplink radio frequency signal sent by the terminal under test; The signal frequency measurement unit is used to measure the frequency of the uplink radio frequency signal received by the radio frequency signal processing unit. 3. The terminal testing device according to claim 2, wherein the signal frequency measurement unit notifies the measured signal frequency to the AFC test control module; The AFC test control module notifies the AFC test result output module of the signal frequency received from the signal frequency measurement unit and the frequency of the configured downlink signal. 4. The terminal testing device according to claim 2, wherein the signal frequency measurement unit notifies the measured signal frequency to the AFC result output module; The AFC test control module notifies the configured frequency of the downlink signal to the AFC result output module. the 5. The terminal testing device according to claim 2, wherein the AFC test control module is further used to configure the signal-to-noise ratio of the downlink signal; The baseband signal processing unit is further configured to, according to the configured SNR, add an additive white Gaussian noise AWGN signal to the downlink signal so that the downlink signal meets the SNR requirement. 6. The terminal testing device according to claim 1, wherein the AFC test result output module is further configured to calculate and output the AFC tracking rate of the terminal under test according to the synchronization relationship between the two curves. 7. The terminal testing device according to any one of claims 1 to 6, further comprising: a parameter setting module, configured to receive an input signal offset parameter and an offset cycle parameter; The AFC test control module is further configured to configure the frequency information of the downlink signal according to the signal offset parameter and the offset period parameter. 8. The terminal testing device according to claim 7, wherein the parameter setting module is further used to receive an input signal-to-noise ratio parameter; The baseband signal processing unit is further configured to, according to the signal-to-noise ratio parameter received by the parameter setting module, add an AWGN signal to the downlink signal so that the downlink signal meets the SNR requirement. 9. A method utilizing the terminal testing equipment as claimed in claims 1 to 8 to test the terminal AFC, characterized in that it comprises: After the terminal testing device sends the downlink signal processed by the frequency offset to the terminal under test, it receives the uplink signal sent by the terminal under test; The terminal testing equipment outputs the frequency curve of the downlink signal, the AFC curve of the terminal under test, and the synchronization relationship between the two curves according to the frequency of the transmitted downlink signal and the frequency of the received uplink signal. 10. The method according to claim 9, wherein the terminal test equipment sends the downlink signal through frequency offset processing, comprising: The terminal test equipment performs frequency offset processing during the baseband processing of the downlink signal, and modulates the baseband processed signal into a radio frequency signal for transmission. the

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