CN113438041B - Method and system for testing responder MTIE - Google Patents
Method and system for testing responder MTIE Download PDFInfo
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- CN113438041B CN113438041B CN202110858923.0A CN202110858923A CN113438041B CN 113438041 B CN113438041 B CN 113438041B CN 202110858923 A CN202110858923 A CN 202110858923A CN 113438041 B CN113438041 B CN 113438041B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/10—Monitoring; Testing of transmitters
- H04B17/15—Performance testing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/59—Responders; Transponders
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/20—Monitoring; Testing of receivers
- H04B17/29—Performance testing
Abstract
The application provides a test method and a test system of a responder MTIE, wherein a control signal generator outputs a set excitation signal to a test antenna, so that the test antenna sends a downlink excitation signal based on the excitation signal; acquiring the antenna power of a test antenna; if the antenna power is within the preset power range, acquiring an uplink signal fed back to the test antenna by the transponder to be tested; demodulating the uplink signal, and counting the code element width of the obtained low-frequency code digital signal; the maximum time interval error MTIE is determined using the standard code rate and symbol width. In the scheme, the test antenna sends down a downlink excitation signal by using the excitation signal, if the antenna power of the test antenna is in a preset power range, the acquired uplink signal fed back to the test antenna is demodulated, the code element width of the low-frequency code digital signal is counted, and the maximum time interval error MTIE is determined by using the standard code rate and the code element width, so that the aim of testing the transponder MTIE is fulfilled.
Description
Technical Field
The invention relates to the technical field of transponders, in particular to a method and a system for testing a Maximum Time Interval Error (MTIE) of a transponder.
Background
The appearance of the rail train brings great convenience to the production and the life of people.
In a rail train control system, a transponder is an important component, and the quality of an uplink signal of the transponder is related to the analysis and restoration of a receiving signal by a vehicle-mounted device, so that the transponder has a direct influence on the running safety of a train. The MTIE is an important parameter for evaluating the quality of the transponder uplink signal. In view of the above, it is desirable to provide a method and system for testing the responder MTIE.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method and a system for testing a responder MTIE, so as to achieve the purpose of testing the responder MTIE.
In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:
the first aspect of the embodiment of the invention discloses a method for testing maximum time interval error MTIE of a responder, which comprises the following steps:
controlling a signal generator to output a set excitation signal to a test antenna, so that the test antenna sends a downlink excitation signal to a to-be-tested transponder based on the excitation signal;
acquiring the antenna power of the test antenna acquired by the power acquisition unit;
if the antenna power is in a preset power range, acquiring an uplink signal which is acquired by a time domain signal acquisition device and fed back to the test antenna by the to-be-tested transponder;
demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal;
and determining the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the code element width.
Optionally, the demodulating the uplink signal based on the hilbert transform to obtain a low-frequency code digital signal, and performing statistics to obtain a symbol width of the low-frequency code digital signal includes:
performing Hilbert transform on the uplink signal to obtain a complex signal corresponding to the uplink signal, wherein the complex signal comprises a signal real part and a signal imaginary part;
performing phase demodulation on the real signal part and the imaginary signal part to determine a phase discontinuity point of the complex signal;
converting the uplink signal to a low frequency code digital signal based on a phase discontinuity of the complex signal;
and counting the code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal.
Optionally, if the standard code rate is a fixed code rate, determining a maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the symbol width includes:
selecting code elements in n sampling windows from the low-frequency code digital signal;
and aiming at the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the fixed code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested responder, wherein n is a positive integer greater than or equal to 2.
Optionally, if the standard code rate is an average code rate, determining a maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the symbol width includes:
selecting code elements in n sampling windows from the low-frequency code digital signal;
and for the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the average code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested transponder, wherein n is a positive integer greater than or equal to 2.
Optionally, after obtaining the uplink signal fed back to the test antenna by the transponder to be tested and collected by the time domain signal collector, the method further includes:
and smoothing the uplink signal.
The second aspect of the embodiment of the invention discloses a system for testing maximum time interval error MTIE of a responder, which comprises:
the control module is used for controlling the signal generator to output a set excitation signal to the test antenna, so that the test antenna sends a downlink excitation signal to the transponder to be tested based on the excitation signal;
the first acquisition module is used for acquiring the antenna power of the test antenna acquired by the power acquisition unit;
the second obtaining module is used for obtaining an uplink signal which is collected by the time domain signal collector and fed back to the test antenna by the to-be-tested transponder if the antenna power is within a preset power range;
the demodulation and statistics module is used for demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal;
and the confirming module is used for determining the maximum time interval error MTIE for testing the transponder to be tested by utilizing the standard code rate and the code element width.
Optionally, the demodulation and statistics module includes:
a transformation unit, configured to perform hilbert transformation on the uplink signal to obtain a complex signal corresponding to the uplink signal, where the complex signal includes a real signal part and an imaginary signal part;
a demodulation and determination unit, configured to perform phase demodulation on the real signal part and the imaginary signal part, and determine a phase discontinuity point of the complex signal;
a conversion unit for converting the uplink signal into a low frequency code digital signal based on a phase jump point of the complex signal;
and the counting unit is used for counting the code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal.
Optionally, if the standard code rate is a fixed code rate, the determining module is specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and aiming at the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the fixed code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested responder, wherein n is a positive integer greater than or equal to 2.
Optionally, if the standard code rate is an average code rate, the determining module is further specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and for the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the average code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested transponder, wherein n is a positive integer greater than or equal to 2.
Optionally, the method further includes:
and the smoothing processing module is used for smoothing the uplink signal.
Based on the testing method and system for the responder MTIE provided by the embodiment of the invention, the set excitation signal is output to the testing antenna through the control signal generator, so that the testing antenna sends the downlink excitation signal to the responder to be tested based on the excitation signal; acquiring the antenna power of the test antenna acquired by the power acquisition unit; if the antenna power is in a preset power range, acquiring an uplink signal which is acquired by a time domain signal acquisition device and fed back to the test antenna by the to-be-tested transponder; demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal; and determining the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the code element width. In the scheme, a test antenna sends a downlink excitation signal to a transponder to be tested by using an excitation signal, if the collected antenna power of the test antenna is in a preset power range, an uplink signal fed back to the test antenna is collected and demodulated, the code element width of the obtained low-frequency code digital signal is counted, and the maximum time interval error MTIE for testing the transponder to be tested is determined by using a standard code rate and the code element width, so that the aim of testing the MTIE of the transponder is fulfilled.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a schematic structural diagram illustrating an IQ signal obtained from an original signal according to a prior art according to an embodiment of the present invention;
fig. 2 is a schematic flowchart of a method for testing a maximum time interval error MTIE of a transponder according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of performing hilbert transform according to an embodiment of the present invention;
fig. 4 is a schematic flowchart of determining a maximum time interval error MTIE according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of another exemplary method for determining the maximum time interval error MTIE according to the present invention;
FIG. 6 is a schematic structural diagram of a system for testing a maximum time interval error MTIE of a transponder according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of another testing system for maximum time interval error MTIE of a transponder according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.
In order to facilitate understanding of the technical solution of the present invention, technical terms appearing in the present invention are explained:
FSK (Frequency shift key, Frequency shift keying modulation): the low-frequency digital signal (digital signal with non-periodic variation of high 1 and low 0) and the high-frequency sinusoidal signal (2 high-frequency sinusoidal signals with one high and one low are commonly used, which respectively represent 1 and 0 of the low-frequency digital signal) are modulated into sinusoidal signals with alternating frequency in the time domain through a multiplier, so as to be conveniently propagated in a medium such as a free space or a transmission cable.
Transponder (Balise): a ground transmission unit using magnetic induction technology. The important function is to transmit data information through the air gap. The transponder is a signal device mounted on a track and communicates with an onboard device passing over it. Transponders are the generic term for active transponders and passive transponders.
Downlink excitation signal: an 27.095MHz sinusoidal signal carrying energy is emitted by the vehicle antenna, and the transponder, upon receiving the energy, activates the circuit and transmits an FSK signal.
Uplink signals: a 4MHz frequency FSK signal carrying information transmitted by the transponder.
Symbol (Symbol): time domain information represented by 1 high (or low) level in the digital signal. The symbol width is the time domain length of a single symbol.
Vsa (vector Signal analyser): vector signal analyzers, or RSGs (real-time signal analyzers).
MTIE (Maximum Time Interval Error): the time interval error TIE is the difference between the sample symbol width and the comparison symbol width.
Briefly, the MTIE, namely, whether the code rate of the low-frequency signal demodulated by the FSK signal meets the standard or not, is different from statistical methods such as averaging, median, and maximum values for a large number of sample symbols in a traditional code rate test, the MTIE performs symbol width estimation on all symbol combinations in a mode of "bit-by-bit growth" and "full sample shift" windowing, and the estimation standard is divided into MTIE1 (adopting the standard code rate) and MTIE2 (adopting the sample average code rate) according to the comparison code rate. Since the sampling window width of the MTIE calculation is from 1 to 1000, MTIE1 corresponds to the MTIE2 evaluation criterion with a sampling window width from 1 to 1000 and is divided into short, medium and long window width segmentation criteria.
The MTIE test improves the resolution of the actual symbol width information as much as possible by using phase demodulation, thereby ensuring the accuracy of the test result.
MTIE evaluation boundaries the piecewise function shown in tables 1 and 2:
table 1: evaluation boundaries of MTIE1
| Corresponding to the number n of code element bits to be investigated | Upper limit ns |
| 1 to 16 positions | 272 |
| 17 to 140 bits | 396 |
| 141 to 1000 bits | 1000n/564.48+148 |
Table 2: evaluation boundaries of MTIE2
| Corresponding to the number n of code element bits to be investigated | Upper limit ns |
| 1 to 16 positions | 236 |
| 17 to 140 bits | 370 |
| 141 to 1000 bits | 2500n/564.48+148 |
In tables 1 and 2, 1-16 bits, 17-140 bits, and 17-140 bits are a sampling window, respectively.
In the prior art, uplink signals are tested by VSA vector signal analyzers, which in use perform FSK decoding of the uplink signals by means of IQ (in-phase quadrature signal) decomposition.
As shown in fig. 1, the method for obtaining IQ signals from original signals is that original signals s (t) are divided into two signals by a separator and then mixed with signals cos (wc × t), one of the two signals is delayed by pi/2 phase (i.e. 90 °) by a delay, and finally the two signals are passed through a low pass filter to obtain i (t) and q (t) signals. The signals I (t) and Q (t) are orthogonal decomposition components of the original signal respectively, and the phase discontinuity point can be obtained in a phase demodulation mode, so that the decoding is realized.
As can be known from the background art, in a rail train control system, a transponder is an important component, and the quality of an uplink signal of the transponder is related to the analysis and restoration of a received signal by a vehicle-mounted device, so that the quality has a direct influence on the safety of train running. The MTIE is an important parameter for evaluating the quality of the transponder uplink signal. In view of the above, it is desirable to provide a method and system for testing the responder MTIE.
In the scheme, a test antenna sends a downlink excitation signal to a to-be-tested transponder by using an excitation signal, if the acquired antenna power of the test antenna is within a preset power range, an uplink signal fed back to the test antenna is acquired and demodulated, the symbol width of the obtained low-frequency code digital signal is counted, and the maximum time interval error MTIE for testing the to-be-tested transponder is determined by using a standard code rate and the symbol width, so that the aim of testing the maximum time interval error MTIE of the transponder is fulfilled.
As shown in fig. 2, a schematic flow chart of a method for testing a maximum time interval error MTIE of a transponder according to an embodiment of the present invention is provided, where the method mainly includes the following steps:
step S201: and the control signal generator outputs the set excitation signal to the test antenna, so that the test antenna sends a downlink excitation signal to the transponder to be tested based on the excitation signal.
In the process of implementing step S201 specifically, each instrument (such as a signal generator, a power amplifier, a power meter, and an oscilloscope) is initialized, the power amplifier is configured, the output of the power amplifier is set, an excitation signal is set on the signal generator, the signal generator is controlled to output the excitation signal set on the signal generator to the test antenna, and the test antenna receives the excitation signal and sends a downlink excitation signal to the transponder to be tested based on the excitation signal.
Step S202: and acquiring the antenna power of the test antenna acquired by the power acquisition unit.
In step S202, a power collector is configured to collect antenna power at the test antenna.
In the process of implementing step S202 specifically, the power collector is used to collect the antenna power of the test antenna, and obtain the antenna power.
Step S203: and judging whether the antenna power is in a preset power range.
In step S203, the predetermined power is an antenna power that can keep the transponder under test operating stably and not in an over-saturated state. This power is defined in the railway standard 3544 d.6.13.5 as the third level of magnetic flux (the magnetic flux within the range of the transponder under test antenna which is fixed in position relative to the test antenna), i.e., +10dB ± 1 dB.
In the process of implementing step S203, it is determined whether the antenna power is within the preset power range, if the antenna power is within the preset power range, step S204 is executed, and if the antenna power is not within the preset power range, step S201 is executed.
Step S204: and acquiring an uplink signal which is acquired by the time domain signal acquisition device and fed back to the test antenna by the transponder to be tested.
In step S204, the uplink signal is denoted by S (t).
In the process of implementing step S204 specifically, it is determined that the antenna power is within the preset power range, the time domain signal collector is used to collect the uplink signal of the transponder to be tested, and the transponder to be tested feeds back the uplink signal to the test antenna, so as to obtain the fed-back uplink signal.
Optionally, after step S204 is executed to obtain an uplink signal fed back to the test antenna by the transponder to be tested and collected by the time domain signal collector, the method further includes:
the uplink signal is smoothed.
In the embodiment of the invention, the smoothing processing is carried out on the uplink signal, so that the signal-to-noise ratio can be increased.
Step S205: demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal.
In the process of implementing step S205 specifically, the uplink signal is subjected to hilbert transform and demodulated to obtain a low-frequency code digital signal, and the symbol width of the low-frequency code digital signal is obtained through statistics.
Optionally, step S205 is executed to demodulate the uplink signal based on the hilbert transform to obtain the low frequency code digital signal, and count a symbol width of the low frequency code digital signal, as shown in fig. 3, which is a schematic flow diagram for performing the hilbert transform according to an embodiment of the present invention, and mainly includes the following steps:
step S301: and performing Hilbert transform on the uplink signal to obtain a complex signal corresponding to the uplink signal.
In step S301, the complex signal includes a real signal part and an imaginary signal part.
The complex signal is denoted by S' (t), the real part of the signal is denoted by I (t), and the imaginary part of the signal is denoted by Q (t).
Hilbert transform, which is obtained by convolution calculation of original real signal s (t) without imaginary part and impulse response h (t)
Wherein the content of the first and second substances,
is s (t) a quadrature signal phase shifted by 90 deg..
In the process of implementing step S201 specifically, according to the formula
Hilbert transform is performed on the uplink signal to obtain a complex signal S' (t) corresponding to the uplink signal, wherein,
is a real signal
Projection in the complex plane.
Step S302: and performing phase demodulation on the real part and the imaginary part of the signal to determine a phase discontinuity point of the complex signal.
In the process of implementing step S302, as shown in step S201, the projection of S (t) onto the complex plane is S ' (t), the real part S (t) and the imaginary part S ' (t) of the signal are different from each other by 90 °, i.e. orthogonal, and the instantaneous phase is arctan of the ratio of the imaginary part S ' (t) and the real part S (t) at a certain time point. Therefore, the instantaneous phase of S' (t) at each sampling point can be obtained, the instantaneous frequency is the derivative of the instantaneous phase, and the frequency change point is the phase mutation point, so that the phase mutation point of the complex signal is determined.
Step S303: the uplink signal is converted to a low frequency code digital signal based on a phase discontinuity of the complex signal.
In step S303, the low frequency code digital signal is a low frequency code 01 of FSK.
In the process of implementing step S303, since the original signal S (t) is an FSK modulation signal, the phase discontinuity point of the complex signal is determined, that is, the boundary information of the FSK low frequency code 01 change can be obtained, that is, the uplink signal is converted into the low frequency code digital signal based on the phase discontinuity point of the complex signal.
Step S304: and counting code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal.
In the process of specifically implementing step S304, after obtaining the boundary information of the FSK low frequency code 01 change, the FSK signal is demodulated, and the number of the low frequency code 01 code elements is calculated to obtain the code element width of the low frequency code 01 code element.
Since the phase demodulation is performed in steps S301 to S304 and S '(t) is obtained by projecting the complex plane in S (t), the 01 symbol width after S' (t) demodulation matches S (t).
Step S206: the maximum time interval error MTIE for testing the transponder under test is determined using the standard code rate and the symbol width.
In step S206, the MTIE is maxtimentervalerror, the maximum time interval error. In brief, the maximum time interval error is to evaluate whether the symbol width is uniformly distributed, and during calculation, the error TIE (len, k) of the 1-bit code width TI (len, k) relative to the average width TImean of the stream is evaluated bit by bit for the continuous 1000-bit code stream.
Where len denotes a 1-bit width, and k denotes the kth bit of the currently selected code stream, then mtie (len) ═ MAX (TIE (len, k) ═ 1: 1000)).
Len is 1, i.e. 1-bit width is evaluated, and MTIE (1:1000) is obtained after Len is increased one by one.
The MTIE1 and MTIE2 are estimates of the fixed bitrate and the average bitrate, respectively (both of them satisfy one of them, and the specific boundaries are shown in table 1 and table 2 above).
Optionally, if the standard code rate is a fixed code rate, step S206 is executed to determine the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the symbol width, as shown in fig. 4, which is a schematic flow chart for determining the maximum time interval error MTIE provided in the embodiment of the present invention, and the method mainly includes the following steps:
step S401: selecting the code elements in n sampling windows from the low-frequency code digital signal.
In the process of implementing step S401, symbols in n sampling windows are selected from the low frequency code digital signal according to the converted low frequency code digital signal.
Step S402: and aiming at the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using a fixed code rate, and taking the maximum code element width error as the maximum time interval error MTIE for testing the responder to be tested.
In step S402, n is a positive integer of 2 or more.
For example, as shown in table 1, a code element in 3 sampling windows is selected from the low frequency code digital signal, for a sampling window of 1 to 16 bits, a sampling window of 17 to 140 bits, and a sampling window of 141 to 1000 bits, a code element width corresponding to the code element in the sampling window of 1 to 16 bits, 17 to 140 bits, and 141 to 1000 bits is obtained, a fixed code rate is used to perform evaluation on the code element width error, so as to obtain a code element width error of the 3 sampling windows, the code element width errors of the 3 sampling windows are compared, so as to obtain a maximum code element width error, and the maximum code element width error is used as a maximum time interval error MTIE for testing the to-be-tested transponder.
Optionally, if the standard code rate is the average code rate, step S106 is executed to determine the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the symbol width, as shown in fig. 5, which is another schematic flow diagram for determining the maximum time interval error MTIE provided in the embodiment of the present invention, and the step mainly includes the following steps:
step S501: selecting the code elements in n sampling windows from the low-frequency code digital signal.
In the process of implementing step S501, symbols in n sampling windows are selected from the low frequency code digital signal according to the converted low frequency code digital signal.
Step S502: and (3) evaluating the code element width error by using the average code rate according to the code element width corresponding to the code element in each sampling window, and taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested transponder.
In step S502, n is a positive integer of 2 or more.
For example, as shown in table 2, a code element in 3 sampling windows is selected from the low frequency code digital signal, for a sampling window of 1 to 16 bits, a sampling window of 17 to 140 bits, and a sampling window of 141 to 1000 bits, a code element width corresponding to the code element in the sampling window of 1 to 16 bits, 17 to 140 bits, and 141 to 1000 bits is obtained, the code element width error of the 3 sampling windows is obtained by performing evaluation on the code element width error by using a fixed code rate, the maximum code element width error is obtained by comparing the code element width errors of the 3 sampling windows, and the maximum code element width error is used as a maximum time interval error MTIE for testing the to-be-tested transponder.
According to the testing method for the maximum time interval error MTIE of the responder, provided by the embodiment of the invention, the set excitation signal is output to the testing antenna through the control signal generator, so that the testing antenna sends a downlink excitation signal to the responder to be tested based on the excitation signal; acquiring antenna power of a test antenna acquired by a power acquisition unit; if the antenna power is in a preset power range, acquiring an uplink signal which is fed back to the test antenna by the to-be-tested transponder and acquired by the time domain signal acquisition device; demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal; the maximum time interval error MTIE for testing the transponder under test is determined using the standard code rate and the symbol width. In the scheme, a test antenna sends a downlink excitation signal to a transponder to be tested by using an excitation signal, if the collected antenna power of the test antenna is in a preset power range, an uplink signal fed back to the test antenna is collected and demodulated, the code element width of the obtained low-frequency code digital signal is counted, and the maximum time interval error MTIE for testing the transponder to be tested is determined by using a standard code rate and the code element width, so that the aim of testing the MTIE of the transponder is fulfilled.
Corresponding to the testing method for the maximum time interval error MTIE of the transponder shown in the above embodiment of the present invention, the embodiment of the present invention further provides a testing system for the maximum time interval error MTIE of the transponder, as shown in fig. 6, where the testing system for the maximum time interval error MTIE of the transponder includes: a control module 61, a first obtaining module 62, a second obtaining module 63, a demodulation and statistics module 64 and a confirmation module 65.
And the control module 61 is used for controlling the signal generator to output the set excitation signal to the test antenna, so that the test antenna sends a downlink excitation signal to the transponder to be tested based on the excitation signal.
And a first obtaining module 62, configured to obtain the antenna power of the test antenna collected by the power collector.
And a second obtaining module 63, configured to obtain, if the antenna power is within the preset power range, an uplink signal fed back to the test antenna by the transponder to be tested, where the uplink signal is collected by the time domain signal collector.
And a demodulation and statistics module 64, configured to demodulate the uplink signal based on the hilbert transform to obtain a low-frequency digital signal, and count to obtain a symbol width of the low-frequency digital signal.
And the confirming module 65 is used for determining the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the code element width.
It should be noted that, the specific principle and the execution process of each module in the testing system for the maximum time interval error MTIE of the transponder disclosed in the embodiment of the present invention are the same as the testing method for implementing the maximum time interval error MTIE of the transponder disclosed in the embodiment of the present invention, and reference may be made to the corresponding parts in the testing method for the maximum time interval error MTIE of the transponder disclosed in the embodiment of the present invention, which are not described herein again.
According to the test system for the maximum time interval error MTIE of the responder, provided by the embodiment of the invention, the set excitation signal is output to the test antenna through the control signal generator, so that the test antenna sends a downlink excitation signal to the responder to be tested based on the excitation signal; acquiring antenna power of a test antenna acquired by a power acquisition unit; if the antenna power is in a preset power range, acquiring an uplink signal which is fed back to the test antenna by the to-be-tested transponder and acquired by the time domain signal acquisition device; demodulating the uplink signal based on Hilbert transform to obtain a low-frequency code digital signal, and counting to obtain the code element width of the low-frequency code digital signal; the maximum time interval error MTIE for testing the transponder under test is determined using the standard code rate and the symbol width. In the scheme, a test antenna sends a downlink excitation signal to a transponder to be tested by using an excitation signal, if the collected antenna power of the test antenna is in a preset power range, an uplink signal fed back to the test antenna is collected and demodulated, the code element width of the obtained low-frequency code digital signal is counted, and the maximum time interval error MTIE for testing the transponder to be tested is determined by using a standard code rate and the code element width, so that the aim of testing the MTIE of the transponder is fulfilled.
Optionally, based on the demodulation and statistics module 64 shown in fig. 6, the demodulation and statistics module 64 includes: the device comprises a transformation unit, a demodulation and determination unit, a conversion unit and a statistic unit.
And the transformation unit is used for performing Hilbert transformation on the uplink signal to obtain a complex signal corresponding to the uplink signal, and the complex signal comprises a signal real part and a signal imaginary part.
And the demodulation and determination unit is used for carrying out phase demodulation on the real part and the imaginary part of the signal and determining a phase mutation point of the complex signal.
A conversion unit for converting the uplink signal into a low frequency code digital signal based on a phase jump point of the complex signal.
And the counting unit is used for counting the code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal.
According to the testing system for the maximum time interval error MTIE of the responder provided by the embodiment of the invention, the complex signal corresponding to the uplink signal is obtained by carrying out Hilbert transform on the uplink signal, phase demodulation is carried out, the phase discontinuity point of the complex signal is determined, and the code element width of the low-frequency code digital signal is solved, so that the testing condition of the MTIE of the responder can be met, and the aim of testing the MTIE of the responder is fulfilled.
Optionally, based on the confirmation module 65 shown in fig. 6, if the standard code rate is a fixed code rate, the confirmation module 65 is specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and aiming at the code element width corresponding to the code element in each sampling window, estimating the code element width error by using a fixed code rate, taking the maximum code element width error as the maximum time interval error MTIE of the transponder to be tested, wherein n is a positive integer greater than or equal to 2.
The test system for the maximum time interval error MTIE of the responder provided by the embodiment of the invention realizes the purpose of testing the MTIE of the responder by determining the maximum time interval error MTIE for testing the responder to be tested by utilizing the standard code rate and the code element width.
Optionally, based on the confirmation module 65 shown in fig. 6, if the standard code rate is the average code rate, the confirmation module 65 is further specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and (3) evaluating the code element width error by using the average code rate according to the code element width corresponding to the code element in each sampling window, taking the maximum code element width error as the maximum time interval error MTIE of the transponder to be tested, wherein n is a positive integer greater than or equal to 2.
The test system for the maximum time interval error MTIE of the responder provided by the embodiment of the invention realizes the purpose of testing the MTIE of the responder by determining the maximum time interval error MTIE for testing the responder to be tested by utilizing the standard code rate and the code element width.
Optionally, based on the testing system for the maximum time interval error MTIE of the transponder shown in fig. 6, in conjunction with fig. 6, as shown in fig. 7, the testing system for the maximum time interval error MTIE of the transponder is further provided with a smoothing module 66.
And a smoothing module 66, configured to smooth the uplink signal.
According to the testing system for the maximum time interval error MTIE of the responder provided by the embodiment of the invention, the signal-to-noise ratio is increased by smoothing the uplink signal, so that the testing condition of the MTIE of the responder is met, and the aim of testing the MTIE of the responder is fulfilled.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the system or system embodiments are substantially similar to the method embodiments and therefore are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described system and system embodiments are only illustrative, wherein the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A method for testing maximum time interval error MTIE of a transponder, said method comprising:
controlling a signal generator to output a set excitation signal to a test antenna, so that the test antenna sends a downlink excitation signal to a to-be-tested transponder based on the excitation signal;
acquiring the antenna power of the test antenna acquired by the power acquisition unit;
if the antenna power is in a preset power range, acquiring an uplink signal which is acquired by a time domain signal acquisition device and fed back to the test antenna by the to-be-tested transponder;
performing Hilbert transform on the uplink signal to obtain a complex signal corresponding to the uplink signal, wherein the complex signal comprises a signal real part and a signal imaginary part, performing phase demodulation on the signal real part and the signal imaginary part to determine a phase mutation point of the complex signal, and converting the uplink signal into a low-frequency code digital signal based on the phase mutation point of the complex signal; counting code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal;
and determining the maximum time interval error MTIE for testing the transponder to be tested by using the standard code rate and the code element width.
2. The method of claim 1, wherein determining the maximum time interval error MTIE for testing the transponder under test using the standard code rate and the symbol width if the standard code rate is a fixed code rate comprises:
selecting code elements in n sampling windows from the low-frequency code digital signal;
and aiming at the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the fixed code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested responder, wherein n is a positive integer greater than or equal to 2.
3. The method of claim 1, wherein determining the maximum time interval error MTIE for testing the transponder under test using the standard code rate and the symbol width if the standard code rate is an average code rate comprises:
selecting code elements in n sampling windows from the low-frequency code digital signal;
and for the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the average code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested transponder, wherein n is a positive integer greater than or equal to 2.
4. The method of claim 1, wherein after obtaining the uplink signal fed back to the test antenna by the transponder under test and collected by the time domain signal collector, further comprising:
and smoothing the uplink signal.
5. A system for testing maximum time interval error MTIE of a transponder, said system comprising:
the control module is used for controlling the signal generator to output a set excitation signal to the test antenna, so that the test antenna sends a downlink excitation signal to the transponder to be tested based on the excitation signal;
the first acquisition module is used for acquiring the antenna power of the test antenna acquired by the power acquisition unit;
the second obtaining module is used for obtaining an uplink signal which is collected by the time domain signal collector and fed back to the test antenna by the to-be-tested transponder if the antenna power is within a preset power range;
a demodulation and statistics module comprising:
a transformation unit, configured to perform hilbert transformation on the uplink signal to obtain a complex signal corresponding to the uplink signal, where the complex signal includes a real signal part and an imaginary signal part;
the demodulation and determination unit is used for carrying out phase demodulation on the real part and the imaginary part of the signal and determining a phase discontinuity point of the complex signal;
a conversion unit for converting the uplink signal into a low frequency code digital signal based on a phase jump point of the complex signal;
the counting unit is used for counting code elements of the low-frequency code digital signal to obtain the code element width of the low-frequency code digital signal;
and the confirming module is used for determining the maximum time interval error MTIE for testing the transponder to be tested by utilizing the standard code rate and the code element width.
6. The system of claim 5, wherein if the standard code rate is a fixed code rate, the confirmation module is specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and aiming at the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the fixed code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested responder, wherein n is a positive integer greater than or equal to 2.
7. The system of claim 5, wherein if the standard code rate is an average code rate, the confirmation module is further specifically configured to:
selecting code elements in n sampling windows from the low-frequency code digital signal; and for the code element width corresponding to the code element in each sampling window, evaluating the code element width error by using the average code rate, taking the maximum code element width error as the maximum time interval error MTIE for testing the to-be-tested transponder, wherein n is a positive integer greater than or equal to 2.
8. The system of claim 5, further comprising:
and the smoothing processing module is used for smoothing the uplink signal.
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| CN101123482A (en) * | 2007-09-14 | 2008-02-13 | 中兴通讯股份有限公司 | A device and method for testing sliding index in digital communication network |
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