CN103037239A - System and method for testing receiving performance of digital video receiving terminal - Google Patents

Abstract

The invention provides a system and method for testing the receiving performance of a digital video receiving terminal. The control device sets parameters to control the signal generating device to generate a radio frequency signal; the digital video receiving terminal receives and demodulates the radio frequency signal; the signal evaluation device evaluates the demodulated The signal is evaluated; the control device adjusts the parameter to be measured according to the evaluation result until the threshold value of the parameter to be measured is determined. Applying the solution of the present invention, due to the newly added control equipment and signal evaluation equipment, it forms a feedback system with the digital video receiving terminal and signal generating equipment, as long as the necessary test items and parameters are provided, the test can be carried out automatically without manual work Participation also greatly improved the accuracy of the test.

Description

A test system and method for receiving performance of digital video receiving terminal

technical field

The invention relates to the technical field of video terminals, in particular to a system and method for testing receiving performance of a digital video receiving terminal.

Background technique

The receiving performance of a digital video receiving terminal can usually be expressed by some indicators, such as signal strength, signal-to-noise ratio, modulation bandwidth, co-channel or adjacent-channel interference intensity and other parameters. The job of the tester is to detect the threshold values of these parameters one by one, so as to evaluate the receiving performance of the terminal. When testing a single test item, testers can fix certain parameters and only change the parameters to be tested. When the single test is finished, the result of the parameter to be tested can be known.

Therefore, testing is a very tedious job. First, testers need to manually set various parameters to control the signal generating equipment to generate qualified radio frequency signals, which simulate the signals received by digital video receiving terminals and input them to data video receiving terminals. The digital video receiving terminal displays the picture according to the received signal, and the testers use their own experience to manually judge whether the picture is normal. This method is not only a great waste of manpower, but also very inaccurate because the test results are related to the subjective judgment of the testers.

Contents of the invention

The invention provides a system and method for testing the receiving performance of a digital video receiving terminal, which can avoid manual operation, greatly save human resources and improve the accuracy of testing.

For achieving above-mentioned first object, the technical scheme that the present invention provides is:

A test system for receiving performance of a digital video receiving terminal, including a digital video receiving terminal and a signal generating device, the system also includes: a control device and a signal evaluation device;

The control device is used to set fixed parameters and parameters to be tested for the test item to control the signal generating device to generate a radio frequency signal when testing a single test item; it is also used to receive the evaluation result output by the signal evaluation device, Adjust the parameter to be tested according to the evaluation result to control the signal generating device to regenerate the radio frequency signal until the threshold value of the parameter to be tested is determined, and use the threshold value as the test result of the parameter to be tested;

The signal generating device modulates and outputs a radio frequency signal to the digital video receiving terminal according to the fixed parameter and the parameter to be tested set by the control device for the test item;

The digital video receiving terminal is used to receive a radio frequency signal from a signal generating device and demodulate the radio frequency signal;

The signal evaluation device is used to evaluate whether the signal demodulated by the digital video receiving terminal is normal or abnormal, and output the evaluation result to the control device.

In the above solution, the control device includes:

A storage unit for storing fixed parameters and parameters to be tested set for the test item;

The transceiver unit is used to output the fixed parameters set for the test items and the parameters to be tested to the signal generating device; it is also used to receive the evaluation results output by the signal evaluation device;

An adjustment unit, configured to adjust the parameter to be measured according to the evaluation result to control the signal generating device to regenerate the radio frequency signal until the threshold value of the parameter to be measured is determined, and use the threshold value as the test result of the parameter to be measured .

In the above scheme, the signal evaluation equipment includes:

a transceiver unit, configured to receive a demodulated signal or a value related to a bit error rate input from the digital video receiving terminal; and also configured to output the evaluation result determined by the analysis unit to the control device;

The analysis unit is used to count the number of error packets according to the demodulated signal, determine the actual bit error rate according to the number of error packets, and then determine the evaluation by comparing the actual bit error rate with the preset standard bit error rate result; or directly obtain the value related to the bit error rate from the digital video receiving terminal to determine the actual bit error rate, and then determine the evaluation result by comparing the actual bit error rate with the preset standard bit error rate.

In the above solution, the control device is a personal computer or a programmable smart machine.

In the above solution, the control device and the signal generating device are connected through a serial port, a network port or a general interface bus GPIB, and the control device and a digital video receiving terminal are connected through a serial port or a network port.

For the second purpose of the invention, the technical solution proposed by the present invention is:

A method of testing applied to the system of claim 1, the method comprising:

A. The control equipment sets fixed parameters and parameters to be tested for the test items to control the signal generating equipment to generate radio frequency signals;

B. The digital video receiving terminal receives the radio frequency signal from the signal generating device, and demodulates the radio frequency signal;

C. The signal evaluation device evaluates whether the signal demodulated by the digital video receiving terminal is normal or abnormal, and outputs the evaluation result to the control device;

D. The control device adjusts the parameter to be tested according to the evaluation result, and returns to step A until the threshold value of the parameter to be tested is determined, and takes the threshold value as the test result of the parameter to be tested.

In the above solution, before step B, it further includes: the control device controls the digital video receiving terminal to initialize, so that the digital video receiving terminal is in a state of being tested.

In the above scheme, the step C includes:

The signal evaluation device receives the demodulated signal input from the digital video receiving terminal, counts the number of error packets according to the demodulated signal, determines the actual bit error rate according to the number of error packets, and then determines the actual bit error rate by The comparison between the actual bit error rate and the preset standard bit error rate determines the evaluation result, and outputs the evaluation result to the control device.

In the above scheme, the step C includes:

The signal evaluation device obtains the value related to the bit error rate from the digital video receiving terminal to determine the actual bit error rate, and then determines the evaluation result by comparing the actual bit error rate with a preset standard bit error rate.

To sum up, the present invention provides a system and method for testing the receiving performance of a digital video receiving terminal, which newly adds a control device and a signal evaluation device to form a feedback system with a digital video receiving terminal and a signal generating device, as long as necessary Test items and parameters can be automatically tested without manual participation, which greatly improves the accuracy of the test.

Description of drawings

FIG. 1 is a schematic structural diagram of a testing system for receiving performance of a digital video receiving terminal of the present invention.

Fig. 2 is a flowchart of a method for performing performance testing on a digital video receiving terminal according to the present invention.

FIG. 3 is an embodiment of the internal structure of the control device 101 in the present invention.

FIG. 4 is an example of the internal structure of the signal evaluation device 104 in the present invention.

FIG. 5 is an embodiment of another test system for receiving performance of a digital video receiving terminal according to the present invention.

Detailed ways

The basic idea of the present invention is to add a control device and a signal evaluation device, and form a closed-loop feedback system with the digital video receiving terminal and the signal generating device. The control device sets a series of parameters to control the signal generating device to generate a radio frequency signal that meets the conditions, and simulate the signal input to the digital video receiving terminal. The digital video receiving terminal demodulates the received signal and sends it to the signal evaluation device for evaluation. The control device then determines whether to readjust the parameters according to the result of the signal evaluation, so as to control the signal generating device to regenerate the radio frequency signal until the control device ends the detection of a single test item.

FIG. 1 is a test system for realizing the receiving performance of a digital video receiving terminal in the present invention. As shown in FIG. 1 , the system includes: a control device 101 , a signal generating device 102 , a digital video receiving terminal 103 , and a signal evaluation device 104 .

Wherein, the control device 101 and the signal evaluation device 104 are newly added devices or modules of the present invention, the signal generating device 102 can use existing devices in the prior art, and the digital video receiving terminal 103 is the object to be tested in the present invention, Detect the pros and cons of its receiving performance.

The functions of each device in the system are described in detail below:

1) The control device 101 is used to set fixed parameters and parameters to be tested for user-specified test items to control the signal generating device 102 to generate radio frequency signals; it is also used to receive the evaluation results output by the signal evaluation device 104, according to The evaluation result adjusts the parameter under test to control the signal generating device 102 to regenerate the radio frequency signal until the threshold value of the parameter under test is determined, and finally the threshold value is used as the test result of the parameter under test.

2) The signal generating device 102, whose function is to modulate and generate radio frequency signals according to the fixed parameters set by the control device 101 for the test items and the parameters to be tested, and output the radio frequency signals to the digital video receiving terminal 103.

3) The digital video receiving terminal 103 is used to receive the radio frequency signal from the signal generating device 102 and demodulate the radio frequency signal.

4) The signal evaluation device 104 is used to evaluate whether the signal demodulated by the digital video receiving terminal 103 is normal or abnormal, and output the evaluation result to the control device 101 .

Fig. 2 is a flow chart of a method for performing performance testing on a digital video receiving terminal by using the above system. As shown in Figure 2, the method includes:

Step 201: The control device 101 sets fixed parameters and parameters to be tested for the test items to control the signal generating device 102 to generate radio frequency signals.

Both the fixed parameters and the parameters to be tested mentioned here are parameters that need to be input to the signal generating device 102, and the specific types thereof vary with different test items. For example, when testing the performance of signal sensitivity, parameters such as modulation method, frequency point, symbol rate, modulation bandwidth, signal-to-noise ratio, channel model of multipath interference, and intensity of co-frequency or adjacent-frequency interference can be set in advance, and these Parameters are fixed parameters and will not change in this single test. At the same time, the signal strength also needs to be set, but this parameter may need to be changed in this single test, that is, the signal strength is the parameter to be tested in this single test. The control device 101 inputs both the fixed parameters and the parameters to be measured to the signal generating device 102, and the signal generating device 102 can generate radio frequency signals that meet the conditions of these parameters. As for how the signal generating device 102 generates the radio frequency signal, it belongs to the prior art and will not be repeated here.

The evaluation result described here may be an evaluation result of a normal or abnormal signal, and the evaluation method thereof will be described in detail in the signal evaluation device 104 below. The control device 101 can judge whether the currently set parameter to be tested has reached the threshold value according to the evaluation result, if so, stop detecting the single test item this time, and use the threshold value as the test result of the parameter to be tested; otherwise, restart Adjust the parameter to be tested. That is to say, the threshold value mentioned here is a critical value leading to normal and abnormal signals, which can reflect the receiving performance of the tested terminal, and its meaning is the same as that in the prior art, so it will not be repeated here.

In practical applications, if the functions of the control device 101 are modularized, an embodiment of its internal structure can be shown in Figure 3, including:

The storage unit 301 is used for storing fixed parameters and parameters to be tested set for the test items.

The transceiver unit 302 is used to output the fixed parameters set for the test items and the parameters to be tested to the signal generating device 102 ; and is also used to receive the evaluation result output by the signal evaluation device 104 .

The adjustment unit 303 is configured to adjust the parameter to be measured according to the evaluation result to control the signal generating device 102 to regenerate the radio frequency signal until the threshold value of the parameter to be measured is determined, and use the threshold value as the test result of the parameter to be measured .

Step 202: The digital video receiving terminal 103 receives the radio frequency signal from the signal generating device 102, and demodulates the radio frequency signal.

The digital video receiving terminal 103 of the present invention is the target device to be detected, and can automatically demodulate the radio frequency signal. Different from the prior art test performance method, since the present invention is automatically detected by the system, there is no need to manually judge whether the picture is normal or not, so the digital video receiving terminal 103 in the present invention does not need to display the demodulated information, only Just demodulate.

In practical applications, if the digital video receiving terminal 103 is not under test, the control device 101 can control the digital video receiving terminal 103 to initialize before step 102, so that the digital video receiving terminal 103 is under test. Of course, if the digital video receiving terminal 103 is already under test, this step can be omitted.

In addition, the signal generating device 102 of the present invention can use existing devices, such as the signal generating device SFU of Rohde & Schwarz. The signal generating device 102 usually has an external controlled interface, and can receive parameters set by the control device 101 .

Step 203 : The signal evaluation device 104 evaluates whether the signal demodulated by the digital video receiving terminal 103 is normal or abnormal, and outputs the evaluation result to the control device 101 .

In practical applications, the signal evaluation device 104 can be set inside the control device 101 as a module, or can be set outside as an independent device. When implementing the evaluation, the signal evaluation device 104 may use software or hardware.

If software is used, the signal evaluation device 104 can directly read the value in the register in the demodulator chip, which is related to the bit error rate, and then determine the actual bit error rate according to this value. In the prior art, the digital video receiving terminal 103 can automatically count the error packets of the demodulated code stream, and save the relevant value in a certain register of the demodulator chip, and the signal evaluation device 104 can obtain the error packet according to the value. code rate. As for how the demodulator chip of the digital video receiving terminal 103 obtains the value related to the bit error rate belongs to the prior art, how the signal evaluation device 104 determines the bit error rate according to the value is also easy to implement, and will not be repeated here.

If a hardware method is adopted, the signal evaluation device 104 can receive the demodulated signal from the digital video receiving terminal 103, count the number of error packets in the demodulated signal by using a counter within a specified time, and then calculate the number of error packets according to the number of error packets. The number determines the actual bit error rate.

Regardless of the way of hardware or software, the signal evaluation device 104 can determine whether the signal is normal or abnormal under the conditions of the currently set parameters according to the bit error rate. This is because the digital video receiving terminal 103 has international or domestic evaluation standards, such as SPEC standards. The standard stipulates that when the actual bit error rate of the demodulated signal exceeds the standard bit error rate, the picture displayed by the signal will not meet the requirements, otherwise it will meet the requirements. Therefore, the signal evaluation device 104 in the present invention determines whether the evaluation result is normal or abnormal according to the comparison between the actual bit error rate and the standard bit error rate. Of course, there are different evaluation standards in practical applications, and users who apply the solutions of the present invention can determine them by themselves.

In practical applications, if the function of the signal evaluation device 104 is modularized, an embodiment of its internal structure is shown in FIG. 4, including:

The transceiver unit 401 is used to receive the demodulated signal input from the digital video receiving terminal 103 or the value related to the bit error rate; it is also used to output the evaluation result determined by the analysis unit 402 to the control device 101;

The analysis unit 402 is used to count the number of error packets according to the demodulated signal, determine the actual bit error rate according to the number of error packets, and then determine by comparing the actual bit error rate with the preset standard bit error rate evaluation result; or directly obtain the value related to the bit error rate from the digital video receiving terminal 103 to determine the actual bit error rate, and then determine the evaluation result by comparing the actual bit error rate with the preset standard bit error rate.

Step 204: The control device 101 adjusts the parameter under test according to the evaluation result, and returns to step 201 until the threshold value of the parameter under test is determined, and takes the threshold value as the test result of the parameter under test.

If the control device 101 does not determine the critical value for the signal to be between normal and abnormal, that is, the threshold value of the parameter to be measured cannot be determined, then the parameter to be measured needs to be adjusted. The control device 101 determines how to adjust the parameter to be measured according to the evaluation result and with reference to a preset adjustment strategy. There are many adjustment strategies in practical applications, such as: pre-set the step size of each adjustment and the number of cycles, and stop the adjustment when the number of cycles is reached; or, pre-set the step size of each adjustment and the accuracy to be achieved, when the test Stop the adjustment when the parameter reaches the precision; or, pre-specify each adjustment according to the "dichotomy" rule, and set the number of cycles, and stop the adjustment when the number of cycles is reached. In a word, there are many ways how to adjust the parameters to be detected, which can be determined by users who apply the solution of the present invention, and will not be repeated here.

Enumerate a preferred embodiment below and illustrate the present invention scheme:

In practical applications, the functions of the control device and the signal evaluation device can be realized by a certain computer, or by two different computers, or by any other programmable intelligent machine, not limited to personal computers . In this embodiment, if the function of the control device and the function of the signal evaluation device are implemented by the same computer, two functional modules can be set in it, namely, the control module 5011 (ie, the control device) and the signal evaluation module 5012 (ie, the signal evaluation module) equipment). For the convenience of operation, a UI operation interface 5013 can also be set in the computer, through which the tester selects the required test items and the initialization parameters of the signal generating device 502 . In addition, the computer can also save a script file 5014 in advance, which is used to record the initialization parameters of the digital video receiving terminal 503, the path of the resource file, and the environment configuration parameters, such as: the source of the video stream, the signal frequency, the control mode (serial port or network) mouth) etc.

Fig. 6 is a flow chart of this embodiment, including:

Step 601: The control module 5011 obtains the test items and initialization parameters that the user needs to test through the UI operation interface 5013, and at the same time, reads the script file 5014 to obtain the initialization parameters related to the digital video receiving terminal 503.

For example: the user selects parameters such as modulation mode, symbol rate, modulation bandwidth, signal-to-noise ratio, signal strength, multipath interference channel model, co-channel or adjacent-frequency interference intensity and other parameters from the UI operation interface, and sets the initial values of these parameters. At the same time, the initialization parameters related to the digital video receiving terminal are read through the script file.

Step 602: The control module 5011 transmits the initialization parameters to the digital video receiving terminal 503 through the serial port or the network port, so that the digital video receiving terminal 503 is initialized.

The initialization parameters described here are parameters related to the digital video receiving terminal 503, and the control module 5011 can control the digital video receiving terminal 503 to initialize according to the initialization parameters, so that the digital video receiving terminal 503 is converted to the state to be tested for subsequent Be prepared for the test work.

In addition, the control module 5011 can also send the initialization parameters to the digital video receiving terminal 503 in other ways.

Step 603: The control module 5011 transmits the initialization parameters to the signal generating device 502 through the serial port or the network port, so that the signal generating device 502 is initialized.

The initialization parameters described here are parameters related to the signal generating device 502 . In addition, similarly, the control module 5011 can also send the initialization parameters to the signal generating device 502 in other ways, such as a general purpose interface bus (GPIB).

The above steps 601 to 603 are for the control module 5011 to complete the initialization of the digital video receiving terminal 503 and the signal generating device 502 . In practical applications, if the user needs to detect multiple test items, the initialization parameters described in step 603 refer to parameters related to multiple test items, so they can be transmitted to the signal generating device 502 in advance, and then in subsequent step 604 Parameters related to a single test item are transmitted to the signal generating device 502 . Of course, in practical applications, the parameters may not be transmitted to the signal generating device in two steps, which is related to the user's actual practice, as long as the fixed parameters for the test items and the parameters to be tested are finally transmitted to the signal generating device.

Step 604: The control module 5011 transmits other parameters related to the test item to the signal generating device 502 according to the test item selected by the user, so that the signal generating device 502 generates a qualified radio frequency signal.

The "other parameters related to the test item" mentioned here refers to other parameters except the initialization parameters in step 603 that enable the signal generating device 502 to generate radio frequency signals that meet the conditions. For example: the user currently wants to test the frequency capture range. After transmitting the basic initialization parameters to the signal generating device 502 in step 603, other parameters such as frequency point, guard interval, constellation number, FEC, etc. can also be transmitted to the signal generating device in this step. 502. In this way, in the test item for testing the frequency capture range, the frequency point is the so-called parameter to be tested, while other parameters are fixed parameters.

Step 605: The digital video receiving terminal 503 receives the radio frequency signal from the signal generating device 502, and demodulates it.

This step can be completed by the digital video receiving terminal 503 itself, or the demodulation can be performed after the control module 5011 issues a command to start demodulation.

Step 606: The signal evaluation module 504 receives the demodulated signal from the digital video receiving terminal 503, and evaluates whether it is normal or abnormal. As mentioned above, the signal evaluation module 504 of this embodiment can also be implemented by software or hardware, and the description will not be repeated here.

Step 607: The signal evaluation module 504 returns the evaluation result to the control module 5011. In practical applications, the signal evaluation module 504 can return the evaluation result to the control module 5011 by itself, or the control module 5011 can actively obtain it.

Step 608: The control module 5011 judges whether the parameter to be tested needs to be adjusted, if yes, adjust according to the preset adjustment strategy, and then return to step 604 for repeated execution; otherwise, execute step 609.

The adjustment strategy in this step is related to the actual application, and its method can refer to the method described in step 204 .

Step 609: Determine the threshold value of the parameter to be tested, and save the threshold value as the test result of the parameter to be tested.

Step 610: Judging whether all the test items have been tested, if yes, exit the procedure; otherwise, return to step 602.

In practical applications, if there are multiple tests, steps 602 to 609 can be re-executed according to the above method to obtain the threshold value of each parameter to be tested one by one. After obtaining all the test results, the control module 5011 can also analyze and summarize all the test results to generate a final test report. Of course, if there is only a single test, there is no need to loop, and step 610 can be omitted.

Let's take the signal sensitivity test as an example to illustrate:

During the first cycle, the initial value of the parameter to be measured (signal strength) is set to X1, and the evaluation result obtained by the signal evaluation module 5012 is normal, then the control module 5011 attenuates the signal strength at intervals of -10dbm, and the obtained signal strength is X2;

During the second cycle, the evaluation result obtained by the signal evaluation module 5012 is normal, and then the control module 5011 continues to attenuate the signal strength at intervals of -10dbm to obtain a signal strength value of X3;

In the third cycle, the evaluation result obtained by the signal evaluation module 5012 is abnormal (the digital video receiving terminal is out of lock), indicating that the threshold value of the signal strength should be between X2 and X3. Therefore, the control module 5011 calls back the signal strength at an interval of 1dbm to obtain a signal strength value of X4;

During the fourth cycle, the evaluation result obtained by the signal evaluation module 5012 is still abnormal, and the control module 5011 continues to call back the signal strength at an interval of 1dbm to obtain a signal strength value of X5;

In the fifth cycle, the evaluation result obtained by the signal evaluation module 5012 is normal (the digital video receiving terminal is re-locked), indicating that the threshold value of the signal strength should be between X4 and X5. Therefore, the control module 5011 attenuates the signal strength at intervals of 0.1 dBm to obtain a signal strength value of X6;

In the sixth cycle, the evaluation result obtained by the signal evaluation module 5012 is normal, and the control module 5011 attenuates the signal strength at intervals of 0.1 dBm to obtain a signal strength value of X7;

In the seventh cycle, the evaluation result obtained by the signal evaluation module 5012 is abnormal (the digital video receiving terminal is out of lock again), indicating that the threshold value of the signal strength should be between X6 and X7. Therefore, the control module 5011 calls back the signal strength at intervals of 0.02dbm to obtain a signal strength value of X8;

In the eighth cycle, the evaluation result obtained by the signal evaluation module 5012 is normal (the digital video receiving terminal is locked again), so X8 can be used as the threshold value of the signal strength. At this time, the precision of the result of the signal sensitivity test item is 0.02dbm, and if the precision needs to be improved, the loop execution can be continued.

The above example uses the step length as an adjustment strategy. In practical applications, other adjustment strategies can also be used to adjust the parameters to be tested, which will not be listed here.

In a word, due to the new addition of control equipment and signal evaluation equipment in the scheme of the present invention, it can form a feedback system with digital video receiving terminal and signal generation equipment, as long as necessary test items and parameters are provided, the test can be carried out automatically. Without manual participation, the accuracy of the test is also greatly improved.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (9)

1. the test macro of a digital video receiving terminal receptivity comprises digital video receiving terminal, signal generating apparatus, it is characterized in that, this system also comprises: control appliance and signal evaluation equipment;

Described control appliance is used for when the single test item of test, and the preset parameter and the parameter to be measured that arrange for this test item produce radiofrequency signal to control described signal generating apparatus; Also be used for receiving the assessment result by the output of signal evaluation equipment, adjust parameter to be measured according to this assessment result and regenerate radiofrequency signal to control described signal generating apparatus, until determine the threshold value of parameter to be measured, and with the test result of this threshold value as parameter to be measured;

Described signal generating apparatus, according to described control appliance for preset parameter and the Parameter Modulation to be measured of test item setting and export radiofrequency signal and give described digital video receiving terminal;

Described digital video receiving terminal is used for receiving the radiofrequency signal from signal generating apparatus, and with this radiofrequency signal demodulation;

Described signal evaluation equipment is used for the signal after the demodulation of digital video reception terminal is carried out normal or unusual assessment, and assessment result is exported to described control appliance.

2. system according to claim 1 is characterized in that, described control appliance comprises:

Memory cell is used for preset parameter and parameter to be measured that storage arranges for test item;

Transmit-Receive Unit is used for and will exports to signal generating apparatus for preset parameter and the parameter to be measured of test item setting; Also be used for receiving the assessment result by the output of signal evaluation equipment;

Adjustment unit is used for adjusting parameter to be measured according to described assessment result and regenerates radiofrequency signal to control described signal generating apparatus, until determine the threshold value of parameter to be measured, and with the test result of this threshold value as parameter to be measured.

3. system according to claim 1 and 2 is characterized in that, described signal evaluation equipment comprises:

Transmit-Receive Unit be used for to receive signal or the value relevant with the error rate after the demodulation of described digital video receiving terminal input; Also be used for the assessment result that analytic unit is determined is exported to described control appliance;

Analytic unit is used for according to the signal after the demodulation number of erroneous packets being added up, and determines the actual error rate according to the number of erroneous packets, relatively determines assessment result by the actual error rate and the standard error code check that sets in advance again; Perhaps directly obtain the value relevant with the error rate from described digital video receiving terminal, to determine the actual error rate, again by relatively more definite assessment result of the actual error rate and the standard error code check that sets in advance.

4. system according to claim 1 is characterized in that, described control appliance is PC or programmable intelligent machine.

5. system according to claim 1 is characterized in that, described control appliance be connected signal generating apparatus and connect by serial ports, network interface or general-purpose interface bus GPIB, described control appliance be connected serial ports, network interface connection with the digital video receiving terminal.

6. method of testing that is applied to the described system of claim 1 is characterized in that the method comprises:

A, control appliance setting produce radiofrequency signal for preset parameter and the parameter to be measured of test item with the control signal generation;

B, digital video receiving terminal receive the radiofrequency signal from signal generating apparatus, and with this radiofrequency signal demodulation;

C, the signal evaluation equipment signal after to the demodulation of digital video reception terminal carries out normal or unusual assessment, and assessment result is exported to described control appliance;

D, described control appliance are adjusted parameter to be measured according to this assessment result, and return steps A and carry out, until determine the threshold value of parameter to be measured, and with the test result of this threshold value as parameter to be measured.

7. method according to claim 6 is characterized in that, also further comprise before the step B: control appliance control figure video reception terminal is carried out initialization, makes the digital video receiving terminal be in tested state.

8. according to claim 6 or 7 described methods, it is characterized in that described step C comprises:

Described signal evaluation equipment receives the signal after the demodulation of described digital video receiving terminal input, according to the signal after the demodulation number of erroneous packets is added up, determine the actual error rate according to the number of erroneous packets, again by the actual error rate and the standard error code check that sets in advance relatively determine assessment result, and assessment result is exported to described control appliance.

9. according to claim 6 or 7 described methods, it is characterized in that described step C comprises:

Described signal evaluation equipment obtains the value relevant with the error rate from described digital video receiving terminal, to determine the actual error rate, again by relatively more definite assessment result of the actual error rate and the standard error code check that sets in advance.

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