WO2014101202A1 - Procédé, dispositif et système d'essai de diaphonie de lignes multiples - Google Patents

Procédé, dispositif et système d'essai de diaphonie de lignes multiples Download PDF

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Publication number
WO2014101202A1
WO2014101202A1 PCT/CN2012/088077 CN2012088077W WO2014101202A1 WO 2014101202 A1 WO2014101202 A1 WO 2014101202A1 CN 2012088077 W CN2012088077 W CN 2012088077W WO 2014101202 A1 WO2014101202 A1 WO 2014101202A1
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Prior art keywords
line
crosstalk
lines
tested
subcarrier
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PCT/CN2012/088077
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English (en)
Chinese (zh)
Inventor
涂建平
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华为技术有限公司
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Priority to PCT/CN2012/088077 priority Critical patent/WO2014101202A1/fr
Priority to CN201280002025.4A priority patent/CN103229472B/zh
Publication of WO2014101202A1 publication Critical patent/WO2014101202A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/46—Monitoring; Testing
    • H04B3/487—Testing crosstalk effects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
    • H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
    • H04M3/34—Testing for cross-talk

Definitions

  • the present invention relates to the field of communications technologies, and in particular, to a multi-line crosstalk testing method, apparatus, and system. Background technique
  • Digital Subscriber Line (DSL) technology is a high-speed transmission technology for data transmission over a telephone twisted pair, Unshielded Twist Pair (UTP), including Asymmetric Digital Subscriber Line (Asymmetrical Digital). Subscriber Line, ADSL), Very High-speed Digital Subscriber Line (VDSL), Integrated Services Digital Network (ISDN)-based ISDN Digital Subscriber Line (IDSL) and single-pair high-speed digital Single-pair High-bit-rate Digital Subscriber Line (SHDSL).
  • ADSL Very High-speed Digital Subscriber Line
  • VDSL Very High-speed Digital Subscriber Line
  • ISDN Integrated Services Digital Network
  • IDSL Integrated Services Digital Network
  • SHDSL single-pair high-speed digital Single-pair High-bit-rate Digital Subscriber Line
  • DSL using passband transmission uses frequency division multiplexing technology to make DSL and the traditional telephone service (POTS) coexist on the same pair of twisted pairs, where DSL occupies In the high frequency band, the POTS occupies the baseband portion below 4 kHz, and the POTS signal and the DSL signal are separated or combined by a splitter/splitter.
  • POTS traditional telephone service
  • the passband transmission xDSL uses Discrete Multi-Tone Modulation (DMT) technology for modulation and demodulation.
  • DMT Discrete Multi-Tone Modulation
  • User cables basically contain multiple pairs (25 pairs or more) of twisted pairs. Different twisted pairs may run a variety of different services. Due to the principle of electromagnetic induction, various types of xDSL work simultaneously with each other. Crosstalk will occur, and some of the lines will experience a sharp drop in performance due to crosstalk problems; especially when the line is long, some lines may not even be able to open any form of DSL at all. business. Crosstalk is the main factor affecting user rate in current DSL modern (such as ADSL, VDSL) systems. It can be divided into far-end crosstalk (FEXT) and near-end crosstalk (NEXT).
  • FEXT far-end crosstalk
  • NEXT near-end crosstalk
  • NEXT has a greater impact than FEXT, but in ADSL/ In VDSL, due to the use of uplink and downlink frequency domain separation and frequency division multiplexing technology, the impact of FEXT is much greater than NEXT, and FEXT will seriously affect the transmission performance of the line.
  • DSM Spec t rum Management-DSM
  • the main purpose of DSM is to optimize and control the transmission power spectrum of the line through the crosstalk information between the lines so that the lines in the same bundle of cables are affected by as little crosstalk as possible during the operation, thereby improving the stability of the line and increasing the reachability of the line. And reduce power consumption.
  • the actual line condition is very complicated.
  • the adjacent ports are not mapped according to the adjacent line order.
  • the adjacent ports may not be in one line bundle, and the adjacent ports may not be adjacent.
  • DSM optimizes the ports in the same bundle.
  • Some of the route topology information provided by the Administrator, some of the Bureau did not record the relevant route topology information when wiring.
  • the record information of the bureau is not very accurate.
  • the information bank of the bureau cannot be updated in time. Therefore, in practical applications, it is often necessary to test the crosstalk effect of each line to optimize the dynamic frequency of each line to minimize the influence of crosstalk.
  • the existing crosstalk test method mainly measures the size of crosstalk by measuring the difference of silence noise when there is crosstalk on the line.
  • each line needs to be individually activated to measure the quiet noise of the line without other line crosstalk.
  • one of the lines is sequentially selected as the interference line, and activated, and the other line is used as the victim line, and the victim line is activated one by one, and the silent noise of the victim line in the activation condition of the crosstalk line is measured, and the silence noise is passed twice.
  • this method can only test one of the lines individually, and other lines cannot work during the test, and must be in a silent state.
  • the measurement time is one by one, and the line needs to be activated frequently, especially for the line size. At the time, the number of measurements required is huge, which has a great impact on the business. Summary of the invention
  • the object of the present invention is to provide a multi-line crosstalk test method, device and system, which can test multiple lines at the same time, can complete crosstalk test quickly and accurately, and the tested line can work normally, and the service to the user The impact is small.
  • a first aspect of the present invention provides a multi-line crosstalk test method, the method comprising:
  • the subcarrier test sequence includes at least one masking frequency point, and shielding the subcarrier signal corresponding to the frequency at the masking frequency point ;
  • the determining, by using each of the plurality of tested lines, a corresponding subcarrier test sequence includes:
  • the method when the acquiring the number of lines of the multiple tested lines, the method further includes:
  • line parameters of the plurality of tested lines where the line parameters include one or any combination of the following: a subcarrier width, a line length, an average line attenuation, an electrical length, and a maximum reachable rate.
  • the masking frequency points are set for the K lines to be tested, and K different subcarrier test sequences are generated, including:
  • the masking frequency point set by the last line to be tested includes all the masking frequency points set by the previous line to be tested, and K different subcarrier test sequences are formed.
  • the shielding frequency set by the ⁇ different subcarrier test sequences is ⁇ * ⁇ ladder way distribution, specifically:
  • Each row represents a masked frequency point included in a subcarrier test sequence, wherein the first row indicates that the first subcarrier test sequence includes one masked frequency point.
  • the second row indicates that the second subcarrier test sequence includes one masking frequency point. ⁇ ⁇ ⁇ ⁇ .
  • the operating parameter information includes a line attenuation H i ( ), a transmit power spectral density ( ), and a noise at the receiving end R X N 0 i Sei (n k , where represents the kth masking frequency of the subcarrier test sequence, H h ; ( ) represents the line of the ith measured line at the kth masking frequency point Attenuation (ie, transfer function), indicating the transmission power spectral density of the jth measured line at the kth shielding frequency point, indicating the noise of the i-th measured line at the receiving end of the kth shielding frequency point, 1 i K,
  • the background noise of the i-th measured line at the first masking frequency point indicates the background noise of the i-th measured line at the kth masking frequency point, ⁇ WR, . ⁇ ) indicates the operating parameter information
  • the signal-to-noise ratio of the first shielded frequency point of the i-th line under test indicates the background noise of the i-th measured line at the kth masking frequency point, ⁇ WR, . ⁇
  • the method further includes:
  • the symmetry is calculated formula ⁇ i th horizontal test line crosstalk coefficient of the j-th test line ⁇ ,;.
  • the crosstalk level coefficient ⁇ specifically:
  • the present invention further provides a multi-line crosstalk test apparatus, where the apparatus includes: a configuration unit, configured to configure a corresponding subcarrier test sequence for each of the plurality of tested lines,
  • the subcarrier test sequence includes at least one masking frequency point, and the subcarrier signal for transmitting the corresponding frequency is shielded at the masking frequency point;
  • a sending unit configured to load, in each of the tested lines, the subcarrier test sequence configured by the configuration unit, and send the test by using each of the tested lines;
  • An acquisition unit configured to collect operation parameter information after each of the tested lines loads and sends the subcarrier test sequence in the sending unit;
  • a calculating unit configured to calculate a crosstalk level coefficient between the two tested lines according to the received operating parameter information corresponding to the plurality of measured lines collected by the collecting unit.
  • the configuring unit includes:
  • Obtaining a subunit configured to acquire the number of lines K of the plurality of tested lines
  • a setting subunit configured to set the shielding frequency point for the K lines to be tested according to the number K of lines acquired by the obtaining subunit, to generate ⁇ different subcarrier testing sequences, wherein at least one of the subcarriers is generated
  • the number of the masking frequency points set in the test sequence is greater than or equal to the number of the lines.
  • the acquiring subunit is further configured to acquire line parameters of the multiple tested lines, Line parameters include one or any combination of the following:
  • the configuration unit further includes:
  • a sorting subunit configured to sort the K lines to be tested according to the size of the line parameter acquired by the acquiring subunit
  • the setting subunit sets a masking frequency point to the K lines to be tested according to the sorting result of the sorting subunit, the number of the shielding frequency points is sequentially increased, and the shielding of the next measured line is set.
  • the frequency point includes all the masking frequency points set by the previous line under test, forming K different subcarrier test sequences.
  • the shielding of the ⁇ different subcarrier test sequence set by the setting subunit is set
  • the frequency points are distributed in a ⁇ * ⁇ step manner, specifically:
  • Each row represents a masked frequency point included in a subcarrier test sequence, wherein the first row indicates that the first subcarrier test sequence includes one masked frequency point.
  • the second row indicates that the second subcarrier test sequence includes one masking frequency point. ⁇ ⁇ ⁇ ⁇ .
  • the operating parameter information collected by the collecting unit includes line attenuation H i ( ), transmission power spectral density, and receiving The noise of the terminal, wherein the k-th shielding frequency point of the sub-carrier test sequence is represented, and H represents the line attenuation (ie, the transmission function) of the ith-tested line at the k-th shielding frequency point, indicating that the j-th column is measured.
  • the transmission power spectral density of the line at the kth shielding frequency point, R X noisy Sei (n k ), represents the noise of the i-th measured line at the receiving end of the kth shielding frequency point, 1 i K , K k ⁇ K , 1 ⁇ j ⁇ k-1;
  • the calculating unit is specifically configured to calculate a crosstalk horizontal coefficient according to a system of equations (Af-n k f
  • ⁇ denotes the crosstalk level coefficient of the jth line under test for the ith line under test
  • ⁇ / denotes the subcarrier spacing, 2 k K , k i K.
  • the calculating unit further includes:
  • ⁇ , ⁇ ) represents the background noise of the i-th measured line at the first masking frequency point
  • ⁇ , ⁇ represents the background noise of the i-th measured line at the kth masking frequency point
  • ⁇ WR, ⁇ ) Indicates a signal-to-noise ratio of the ith measured channel at the first masking frequency point in the operation parameter information.
  • the device further includes:
  • a detecting unit configured to acquire a known crosstalk level coefficient
  • the calculating unit uses the known crosstalk horizontal coefficient obtained by the detecting unit as an input of a system of equations ( ⁇ / ⁇ ) 2 -
  • 2 ⁇ ( ) + ⁇ RxNoise i n k ) And calculating, according to the operating parameter information collected by the collecting unit, a crosstalk horizontal coefficient between the remaining plurality of tested lines.
  • the present invention further provides a multi-line crosstalk test system, where the system includes: a spectrum management center unit, a plurality of transmitting ends and a receiving end corresponding to the tested line;
  • the spectrum management center unit configures a corresponding subcarrier test sequence for each of the plurality of tested lines, where the subcarrier test sequence includes at least one masked frequency point, and the shielded frequency point is shielded and transmitted. a subcarrier signal corresponding to the frequency;
  • the transmitting end of each of the tested lines loads the subcarrier test sequence corresponding to each of the tested lines, and sends the subcarrier test sequence to the corresponding receiving end via the each tested line;
  • the spectrum management center unit collects the operation parameter information of each of the tested lines, and calculates crosstalk between the two tested lines according to the operation parameter information received by the plurality of measured lines. Horizontal factor.
  • the spectrum management center unit acquires a number of lines K of the plurality of tested lines, and sets the line for the K lines to be tested. Shielding frequency points, generating ⁇ different subcarrier test sequences, wherein the number of the mask frequency points set in at least one of the subcarrier test sequences is greater than or equal to the number of lines ⁇ .
  • the multi-line crosstalk test method, device and system provided by the invention use sub-carrier shielding (tone blackout) to set shielding frequency points of different styles of sub-carriers, construct different sub-carrier test sequences ⁇ ij, and use each sequence irrelevant sexuality, calculate the crosstalk level coefficient between the two lines to be tested, and only need to transmit the subcarrier test sequence once on each line to be tested. It can test multiple lines at the same time, and can complete the crosstalk test quickly and accurately. The tested line can work normally and has little impact on the user's business.
  • sub-carrier shielding tone blackout
  • FIG. 1 is a schematic diagram of a multi-channel DSL access system based on a multi-line crosstalk test method provided by the present invention
  • FIG. 3 is a schematic diagram of a subcarrier test sequence in a downlink direction according to Embodiment 1 of the present invention
  • 4 is a flowchart of a multi-line crosstalk test method according to Embodiment 2 of the present invention
  • FIG. 5 is a schematic diagram of a multi-line crosstalk test apparatus according to Embodiment 3 of the present invention.
  • FIG. 6 is a schematic diagram of a multi-line crosstalk test apparatus according to Embodiment 4 of the present invention.
  • FIG. 7 is a schematic diagram of a multi-line crosstalk test system according to Embodiment 5 of the present invention. detailed description
  • FIG. 1 is a schematic diagram of a multi-channel DSL access system based on the multi-line crosstalk test method of the present invention, as shown in FIG.
  • the system includes a subscriber end DSLAM 120 and a central office DSLAM 150.
  • the client DSLAM 120 includes a client transceiver unit 121 and a split/integrator 122.
  • the client transceiver unit 121 receives the DSL signal from the computer 110 and amplifies the received signal to process the processed DSL signal.
  • the split/conformer 122 integrates the DSL signal from the client transceiver unit 121 and the POTS signal of the telephone terminal 130; the integrated signal is transmitted through the multi-channel UTP 140, by the central office
  • the split/conformer 151 in the DSLAM 150 receives; the split/conformer 151 separates the received signals, and transmits the POTS signals therein to a Public Switched Telephone Network (PSTN) 160, which will be the DSL signal.
  • PSTN Public Switched Telephone Network
  • the transceiver unit 152 sends the received signal to the network management system (NMS) 170. In the downstream direction of the signal, the signals are transmitted in the reverse order of the above.
  • NMS network management system
  • VDSL2 very high speed digital subscriber line
  • the DSLAM terminal cannot obtain the crosstalk information between the Legacy line and the Legacy line by itself, and needs to be obtained by a separate crosstalk test method.
  • vectorized DSL Vectored-DSL
  • VDSL2 vectorized DSL
  • VDSL2 Since VDSL2 technology is earlier than Vectored-DSL technology and has been widely used, it is necessary to consider VDSL2 Legacy user front-end devices (Customer Premises Equipment) that are compatible with existing networks and do not support Vectored-DSL when upgrading VDSL2 to Vectored-DSL. CPE), such as a modem modem.
  • CPE Vectored-DSL
  • the VDSL2 Legacy CPE does not support the transmission and reception of pilot sequences and feedback errors in the Sync Symbol, which makes it difficult for the Vectoring Control Entity (VCE) to estimate the crosstalk coefficient between the Vector line and the legacy line. Therefore, the application of Vectored-DSL technology is limited by the long-term coexistence with Legacy VDSL2.
  • Dynamic Spectrum Management DSM is primarily used in pure Legacy VDSL2, as well as in legacy VDSL2 and Vectored-DSL hybrid scenarios. If there is no detailed crosstalk between the Legacy line and the Legacy line, and between the Legacy line and the Vector line, the DSM will not work effectively.
  • the multi-line crosstalk test method and device provided by the invention can be applied to the DSM system to obtain crosstalk information between lines, to optimize the transmission power spectrum of each line, to pre-compensate the crosstalk of the line or to select a line with less crosstalk. Communication, minimize crosstalk effects, improve line stability, increase line reachability, and reduce power consumption.
  • the invention can also be applied to the detection of the line communication state, and the faulty line is judged by the line crosstalk condition to ensure the effective operation of the line.
  • the Spectrum Management Center is an important functional module in the DSM system.
  • the SMC connects to the user's network terminal such as a modem via a DSLAM via a multiplex line.
  • the SMC can be integrated into the DSLAM or it can be used as a separate server to control the DSLAM.
  • FIG. 2 is a flowchart of a multi-line crosstalk test method provided in this embodiment. As shown in FIG. 2, the method of the present invention includes:
  • Step S101 The SMC configures a corresponding subcarrier test sequence for each of the plurality of tested lines.
  • the SMC pre-configures multiple subcarrier test sequences and stores them in the management information base (Management).
  • the far-end crosstalk between the two lines LI and L2 includes two directions: the downlink direction and the uplink direction, the downlink direction L2 crosstalk to L1 and the uplink direction L1 to L2 crosstalk coefficient have a dual relationship, that is, in the case of the same frequency
  • the crosstalk horizontal coefficients in both directions are equal. Therefore, the SMC can construct subcarrier test sequences in two directions in the constructed subcarrier test sequence, respectively calculate the crosstalk horizontal coefficients in two directions, or can construct only one direction (uplink or downlink) subcarriers.
  • the sequence is tested to calculate the horizontal crosstalk level coefficient in one direction, and then the crosstalk horizontal coefficient in the other direction is calculated by the symmetric relationship.
  • the subcarrier test sequence in the downlink direction is described as an example, but the present invention is not limited thereto.
  • the SMC configures a corresponding subcarrier test sequence for each of the plurality of tested lines, including:
  • Step S101 The SMC acquires the number K of lines of the plurality of tested lines.
  • Step S1012 The SMC sets the mask frequency point for the K lines to be tested, and generates K different subcarrier test sequences.
  • the subcarrier test sequence includes at least one masking frequency point, and the subcarrier signal corresponding to the frequency is shielded at the masking frequency point, that is, no signal is transmitted at the masking frequency point.
  • the SMC constructs a subcarrier test sequence in a stepwise manner, the number of the masked frequency points is sequentially increased, and the shielding frequency points set by the next measured line include all the shielding frequency points set by the previous measured line, forming K different subcarrier test sequences.
  • the shielding frequency points set by the K different subcarrier test sequences are distributed in a K*K ladder manner, specifically:
  • Each row represents a masked frequency point included in a subcarrier test sequence, wherein the first row indicates that the first subcarrier test sequence includes one masked frequency point.
  • the second row indicates that the second subcarrier test sequence includes one masking frequency point. ⁇ ⁇ ⁇ .
  • the method further includes: acquiring line parameters of each of the tested lines.
  • the line parameters include one or any combination of the following: subcarrier width, line length, electrical length, average line attenuation, maximum reachable rate.
  • the measured line may be first sorted according to the obtained size of the line parameter; and according to the sorted result, the masked frequency points are sequentially set to the tested line to form a plurality of lines.
  • K templates can be generated by using any one or several template parameter combinations in the template parameters, including Tone Blackout, RFI notch, and PSDMASK parameters.
  • Tone Blackout is used as a template parameter to set the mask frequency as an example.
  • the present invention is not limited thereto, and the mask frequency can be set by using RFI notch and PSDMASK as template parameters.
  • the line to be tested includes K lines to be tested, that is, line L 1 to line LK, and each line to be tested may have different lines.
  • the line parameters for example, the subcarrier width of the line L1 may be 8M, the subcarrier width of the line L2 is different or length, and the like.
  • the shielding frequency point nl is set on the line L1, the shielding frequency point nl and the shielding frequency point n2 are set on the line L2, the shielding frequency point nl, the shielding frequency point n2 and the shielding frequency point n3 are set on the line L3, and the shielding is set on the line LK.
  • the frequency point nl ⁇ nK that is, the mask frequency is set according to the ⁇ * ⁇ step mode shown in Equation 1.
  • the US indicates the uplink direction
  • the DS indicates the downlink direction
  • the mask frequencies n1 to nK are both set in the downlink direction.
  • the shielding frequency point n1 is set in all the tested lines, that is to say, all the tested lines do not transmit subcarrier signals at this shielding frequency point nl, and there is no mutual crosstalk between the tested lines.
  • the measured noise signal at the receiving end is the background noise of the line (ie, white noise).
  • each column in the ⁇ * ⁇ step matrix can be repeated multiple times, that is, the number of columns included in the ladder matrix can be greater than ⁇ , that is, it can also be set on all lines to be tested.
  • Multiple identical shielding frequency points for example, another shielding frequency point ⁇ ⁇ is set on all the tested lines, and the shielding frequency point ⁇ ⁇ is different from the shielding frequency point nl, that is, the corresponding frequency is different
  • Finding the average value improves the calculation accuracy of white noise.
  • the frequency point similarly, may even be plural, and thus, the number of shielding frequency points set on the line LK may be greater than K.
  • the SMC can map the template to the port template of the corresponding line of the tested line according to the rule that the number of masked frequency points of the subcarriers has the least impact on all line performances. Specifically, any one of the following can be used:
  • Step S102 The SMC controls the sending end of each tested line to load the subcarrier test sequence corresponding to each tested line, and sends the corresponding test line to each corresponding one of the tested lines. The receiving end of the line to be tested.
  • the sender can be either a DSLAM or a user's network terminal device (such as CPE).
  • the downlink direction refers to the direction in which the data transmission direction is sent by the DSLAM to the CPE
  • the uplink direction refers to the direction in which the data transmission direction is sent by the CPE to the DSLAM.
  • the DSLAM directly loads the subcarrier test sequence configured by the SMC to the line under test and sends it to the receiver.
  • the DSLAM first transmits the subcarrier test sequence configured by the SMC to the CPE of each user through the downlink data. After receiving the subcarrier test sequence corresponding to the test line, the CPE loads and A corresponding subcarrier test sequence is sent to the DSLAM.
  • Step S1 03 The SMC collects operation parameter information on each tested line.
  • Operation parameter information including line attenuation H i ( ), transmission power spectral density signal to noise ratio SNR, (n k ) and noise RxNoisei ( ) at the receiving end.
  • H i ( ) represents the line attenuation (ie, the transfer function) of the ith tested line at the kth masking frequency point, indicating that the jth
  • the transmission power spectral density of the measured line at the kth shielding frequency point, R x noisy Sei (n k ) represents the noise of the i-th measured line at the receiving end of the kth shielding frequency point, ⁇ WR, ⁇ ) indicates the i-th
  • the operating parameters corresponding to the values of different i, j and k can be collected at the receiving end.
  • Step S104 The SMC calculates a crosstalk level coefficient between the two tested lines according to the operation parameter information that is received by the plurality of tested lines. Specifically include:
  • Step S1041 The SMC calculates the background noise when there is no crosstalk for each line under test.
  • step S1041 is based on the following formula:
  • step S1 If the operation parameter information collected in step S103 includes the line attenuation H ComputerJ, the transmission power spectral density ( ), the signal-to-noise ratio, and the noise RxNoise person n k at the receiving end, then this step S1 (M1 is according to the following formula:
  • Equation 3 calculates the background noise without crosstalk for each line under test.
  • Step S1042 The equation group formed by the relationship between the noise of the receiving end of each measured line and the line attenuation, the transmission power spectral density, and the background noise without crosstalk according to the same shielding frequency point.
  • Equation 4 calculates the crosstalk level coefficient, where 2 k K , k ⁇ i ⁇ K, denotes the jth The crosstalk level coefficient of the measured line to the ith measured line, ⁇ / indicates the subcarrier spacing, and the minimum is 4.3125 ⁇ , indicating the kth masking frequency point of the subcarrier test sequence.
  • the masking frequency point nl has a sequence number of 1, then 4.3125 ⁇ .
  • the set masking frequency point can also calculate the corresponding serial number according to the relationship. If the subcarrier spacing ⁇ / is 4.3125 ⁇ , the masking frequency of the frequency of 8.625 ⁇ is 2. For the subcarrier width of 3 , the number of shielding frequency points that can theoretically be 30 ⁇ / 4. 3125 KHz.
  • Equation 4 is specifically a system of equations:
  • Equation 4 is specifically a system of equations:
  • the crosstalk level coefficient 1 to 3 ⁇ 41 calculated by Equation 5 is substituted into Equation 6, and crosstalk can be calculated.
  • Equation 4 is specifically the equation:
  • the crosstalk between the lines under test is basically only related to the spatial position of the line, the crosstalk level coefficient and the crosstalk level coefficient are symmetrical.
  • the information of the circuit under test using a plurality of masked frequencies is combined to form a system of equations, thereby calculating the crosstalk level coefficient between the two lines of the measured line, and obtaining a downlink crosstalk channel matrix.
  • the multi-line crosstalk test method provided by the present invention may further include: calculating a crosstalk channel matrix in another direction according to the symmetry of the uplink crosstalk and the downlink crosstalk. That is to say, after obtaining crosstalk in a certain direction (uplink/downlink) of another specific line to another line, crosstalk of the other line to the other direction of the specific line can be obtained.
  • step S104 When the SMC sets the subcarrier test sequence in two directions, it can be calculated by the method in step S104, and thus, this step is not an essential step.
  • the method provided in this embodiment only needs to transmit the subcarrier test sequence ⁇ l on each line to be tested, and the crosstalk level coefficient between the two lines to be tested can be calculated by using the irrelevance of each sequence, which is fast and accurate.
  • the crosstalk level coefficient is estimated.
  • the method provided in this embodiment is applicable to a scenario where a pure Legacy VDSL2, a pure Vec tored-DSL, and a Legacy VDSL2 and a Vec tored-DSL are mixed, and crosstalk information between various types of lines is obtained.
  • This embodiment uses a scenario in which Legacy VDSL2 and Vec tored-DSL are mixed as an example.
  • the Vec tored-DSL system uses the estimated downlink precoding matrix and the uplink cancellation matrix to obtain crosstalk information between the Vec tor lines and crosstalk information between the Legacy line and the Vec tor line.
  • the crosstalk information obtained by the Vec tored-DSL system uses the crosstalk information obtained by the Vec tored-DSL system, the calculation of other unknown crosstalk information in the hybrid scene is accelerated, and the crosstalk information of the Legacy line to the Legacy line and the Vec tor line to the Legacy line is obtained, that is, the known crosstalk level coefficient and the acquisition are used.
  • the combination of the operating parameters can be calculated to shorten the calculation time.
  • FIG. 4 is a flowchart of a multi-line crosstalk test method provided in this embodiment. As shown in FIG. 4, the method includes:
  • Step S201 The SMC configures a corresponding subcarrier test sequence for each of the plurality of tested lines.
  • the SMC can also configure the corresponding subcarrier test sequence only for the Legacy line, so as to avoid loss of performance of the Vec tor line.
  • Step S202 The sender of each tested line is loaded with the subcarrier test sequence corresponding to each tested line, and is sent to each corresponding one of the tested lines via the tested line. The receiving end of the line.
  • the steps S201 and S202 are the same as the steps S101 and S102 in the first embodiment, and are not described here.
  • Step S203 The SMC collects operation parameter information of each tested line.
  • the different types of the tested lines may be separately collected, and the operating parameters of the Legacy line and the operating parameters of the Vec tor line are collected.
  • the receiving end can also collect the crosstalk channel matrix between the Vec tor line and the Vec tor line, that is, the crosstalk level coefficient between the two Vec tor lines.
  • the operating parameters of the Legacy line collected by the receiver include the crosstalk information of the Legacy line to the Vec tor line, and the crosstalk information of the Legacy line to the Legacy line.
  • Step S204 The SMC acquires a known crosstalk level coefficient.
  • the known crosstalk level coefficient refers to the crosstalk level coefficient calculated by the direct measurement method or other methods other than the present invention.
  • the VCE of the Vectored_DSL system is used to obtain the crosstalk horizontal coefficient of the Vector line to the Vector line according to the operation parameters of the Vector line. .
  • the Vectored-DSL system synchronizes with the VCE through the synchronization symbol Sync Symbol, and the transmitting end jointly modulates the pilot sequence on the Sync Symbol of all lines, and the receiving side receives and feeds back the error to the VCE, thereby being at the VCE.
  • the downlink precoding matrix and the uplink cancellation matrix are estimated, and then the vectorization technique described above is applied to cancel the FEXT. In this way, VCE can be used to estimate the crosstalk channel matrix of the Vector line to the Vector line.
  • Step S205 The SMC calculates a crosstalk level coefficient between the two tested lines according to the operating parameter information and the known crosstalk level coefficient corresponding to the plurality of measured lines.
  • the crosstalk level coefficient of the Legacy line to the Vector line is first calculated according to the equation of Equation 4, and the specific calculation process and the first embodiment Step S104 is similar, and the remaining crosstalk level coefficients are calculated using the known or calculated partial crosstalk level coefficients.
  • the symmetry formula is used to calculate the crosstalk level coefficient between the two lines under test to form a crosstalk communication matrix.
  • the method provided by the invention sets a plurality of shielding frequency points in the subcarrier test sequence to form an uncorrelated test sequence, and calculates a crosstalk horizontal coefficient between the tested lines, and the subcarrier shielding (tone blackout) has less influence on the user. It is possible to keep the service uninterrupted, and to reduce the influence of the number of shielded subcarriers on the overall performance of the transmitted line by using the distribution principle of the tone blackout as little as possible.
  • the multi-line crosstalk test apparatus of the present invention includes: a configuration unit 10, a transmitting unit 20, an acquisition unit 30, and a calculation unit 40.
  • the configuration unit 10 is configured to configure a corresponding subcarrier test sequence for each of the plurality of tested lines, where the subcarrier test sequence includes at least one masking frequency point, and the shielding frequency is shielded and transmitted.
  • a subcarrier signal corresponding to the frequency is configured to configure a corresponding subcarrier test sequence for each of the plurality of tested lines, where the subcarrier test sequence includes at least one masking frequency point, and the shielding frequency is shielded and transmitted.
  • the configuration unit 10 pre-configures a plurality of subcarrier test sequences and stores them in the management information base.
  • the far-end crosstalk between the two lines L1 and L2 includes two directions: the downlink direction and the uplink direction, the crosstalk of the L2 to the L1 in the downlink direction and the crosstalk coefficient of the L1 and L2 in the uplink direction have a dual relationship, that is, in the case of the same frequency
  • the crosstalk horizontal coefficients in both directions are equal. Therefore, the configuration unit 10 can construct the subcarrier test sequences in two directions respectively in constructing the subcarrier test sequence, and subsequently calculate the crosstalk horizontal coefficients in the two directions respectively, or can also construct only one direction (uplink direction or downlink direction).
  • the subcarrier test sequence is obtained by subsequent calculation of the crosstalk horizontal coefficient in one direction, and then the crosstalk horizontal coefficient in the other direction is calculated through the symmetric relationship.
  • the configuration unit 10 is described by taking a subcarrier test sequence configured in the downlink direction as an example, but the present invention is not limited thereto.
  • the configuration unit 10 specifically includes: an obtaining subunit and a setting subunit.
  • the obtaining subunit is configured to acquire the number of lines ⁇ of the plurality of tested lines.
  • the setting subunit is configured to set the shielding frequency point for the measured line according to the acquisition subunit according to the number of lines acquired by the obtaining subunit, and generate ⁇ different subcarrier testing sequences.
  • the subcarrier test sequence includes at least one masking frequency, and the subcarrier signal corresponding to the frequency is shielded at the masking frequency point, that is, no signal is transmitted at the masking frequency point.
  • the number of the masking frequencies set in at least one of the subcarrier test sequences in the subcarrier test sequence is greater than the number of lines K.
  • the setting sub-unit constructs a sub-carrier test sequence in a stepwise manner, the number of the shielding frequency points is sequentially increased, and the shielding frequency points set by the latter one of the tested lines include all shielding frequency points set by the previous measured line. , forming a different subcarrier test sequence.
  • the one The masking frequency points set by different subcarrier test sequences are distributed in a ⁇ * ⁇ step manner, as shown in Equation 1.
  • the acquiring subunit is further configured to acquire line parameters of the multiple tested lines, where the line parameters include one or any combination of the following:
  • the configuration unit 10 further includes: a sorting subunit, configured to sort the ⁇ lines to be tested according to the size of the line parameter acquired by the obtaining subunit.
  • the setting subunit sets a masking frequency point to the tested line in sequence according to the result of the sorting subunit sorting, the number of the shielding frequency points is sequentially increased, and the shielding of the next measured line is set.
  • the frequency point includes all the masking frequency points set by the previous line to be tested, forming a different subcarrier test sequence.
  • the line to be tested includes K lines to be tested, that is, line L 1 to line LK, and each line to be tested may have different lines.
  • the line parameters for example, the subcarrier width of the line L1 may be 8M, the subcarrier width of the line L2 is different or length, and the like.
  • the shielding frequency point nl is set on the line L1, the shielding frequency point nl and the shielding frequency point n2 are set on the line L2, the shielding frequency point nl, the shielding frequency point n2 and the shielding frequency point n3 are set on the line L3, and the shielding is set on the line LK.
  • the frequency point nl ⁇ nK that is, the mask frequency is set according to the ⁇ * ⁇ step mode shown in Equation 1.
  • the US indicates the uplink direction
  • the DS indicates the downlink direction
  • the mask frequencies n1 to nK are both set in the downlink direction.
  • the shielding frequency point n1 is set in all the tested lines, that is to say, all the tested lines do not transmit subcarrier signals at this shielding frequency point nl, and there is no mutual crosstalk between the tested lines.
  • the measured noise signal at the receiving end is the background noise of the line (ie, white noise).
  • each column in the K*K step matrix can be repeated multiple times, that is, the number of columns included in the ladder matrix can be greater than ⁇ , that is, it can also be set on all lines to be tested.
  • Multiple identical shielding frequency points for example, another shielding frequency point ⁇ ⁇ is set on all the tested lines, and the shielding frequency point ⁇ ⁇ is different from the shielding frequency point nl, that is, the corresponding frequency is different
  • White noise is calculated and the calculation accuracy of white noise is improved by obtaining the average value.
  • the number of shielding frequency points set on the line LK may be greater than K.
  • the sending unit 20 is configured to load the subcarrier test sequence of the configuration unit configuration in each of the tested lines, and send the signal through each of the tested lines.
  • the collecting unit 30 is configured to collect operating parameter information of each of the tested lines after the transmitting unit loads and transmits the subcarrier testing sequence.
  • the operational parameter information includes line attenuation H i ( ), transmission power spectral density signal-to-noise ratio SNR, (n k ), and noise RxNoisei ( ) at the receiving end.
  • H i ( ) represents the line attenuation (ie, the transfer function) of the ith tested line at the kth masking frequency point, indicating that the jth
  • the transmission power spectral density of the measured line at the kth shielding frequency point, R x noisy Sei (n k ) represents the noise of the i-th measured line at the receiving end of the kth shielding frequency point, ⁇ WR, ⁇ ) indicates the i-th
  • the operating parameters corresponding to the values of different i, j and k can be collected at the receiving end.
  • the calculating unit 40 is configured to calculate a crosstalk level coefficient between the two tested lines according to the operation parameter information received by the plurality of measured lines collected by the collecting unit.
  • the calculation unit 40 includes a first calculation subunit, a second calculation subunit, and a third calculation subunit.
  • the first calculation subunit is configured to calculate background noise when the test line is free of crosstalk. If the operation parameter information collected by the acquisition unit 30 includes the line attenuation H ComputerJ, the transmission power spectral density, and the noise at the receiving end, the first calculation subunit calculates the background noise of each test line without crosstalk according to Equation 2.
  • the first calculating subunit calculates each test line according to Equation 3. Background noise without crosstalk.
  • the second calculating sub-unit is configured to calculate a crosstalk level according to a relationship between noise at the receiving end of each measured line and the relationship between line attenuation, transmission power spectral density, and background noise without crosstalk at the same shielding frequency point. Coefficient ⁇ ⁇ .
  • the second calculation subunit calculates the crosstalk horizontal coefficient ⁇ according to the equations of Equation 4, and for the different values of k, Equation 4 can be expanded into a system of equations as shown in Equations 5 to 7, and each crosstalk is calculated column by column. Horizontal factor.
  • the third calculation subunit is configured to calculate the crosstalk horizontal coefficient of the ith measured line to the jth measured line according to the symmetry formula.
  • the crosstalk between the lines under test is basically only related to the spatial position of the line, the crosstalk level coefficient and the crosstalk level coefficient are symmetrical.
  • the information of the circuit under test using a plurality of masked frequencies is combined to form a system of equations, thereby calculating the crosstalk level coefficient between the two lines of the measured line, and obtaining a downlink crosstalk channel matrix.
  • the third calculating subunit is further configured to calculate a crosstalk channel matrix in another direction according to the symmetry of the uplink crosstalk and the downlink crosstalk. That is to say, after the third computing sub-unit obtains crosstalk in a certain direction (uplink/downlink) of another specific line to another line, crosstalk of the other line to the other direction of the specific line can be obtained.
  • the multi-line crosstalk test apparatus of the present invention may further include: a detecting unit 50, configured to acquire a known crosstalk level coefficient.
  • the known crosstalk level coefficient refers to the crosstalk level coefficient calculated by the direct measurement method or other methods other than the present invention.
  • the VCE of the Vec tor ed_DSL system is used to obtain the crosstalk of the Vector line to the Vector line according to the operation parameters of the Vector line. Horizontal factor.
  • the Vectored-DSL system synchronizes with the VCE through the synchronization symbol Sync Symbol, and the transmitting end jointly modulates the pilot sequence on the Sync Symbol of all lines, and the receiving side receives and feeds back the error to the VCE, thereby being at the VCE.
  • the downlink precoding matrix P and the uplink cancellation matrix W are estimated, and then the above vectorization technique is applied.
  • the VCE can be used to estimate the crosstalk channel matrix of the Vector line to the Vector line.
  • the second calculation sub-unit uses the operating parameters of the Vector line to be acquired, and uses the VCE to estimate the crosstalk channel matrix of the Vector line to the Vector line.
  • the crosstalk horizontal coefficient of the Legacy line to the Vector line is first calculated, and the specific calculation is performed.
  • the process is similar to step S104 in the first embodiment, and the remaining crosstalk level coefficients are calculated using the known or calculated partial crosstalk level coefficients.
  • the third computing sub-unit uses the symmetry formula to calculate the crosstalk horizontal coefficient between the two measured lines to form a crosstalk communication matrix.
  • FIG. 6 is a schematic structural diagram of a multi-line crosstalk test apparatus according to an embodiment of the present invention.
  • the multi-line crosstalk test apparatus of the embodiment of the present invention may include:
  • the processor 601, the memory 602, and the communication interface 604 are connected by the system bus 603 and complete communication with each other.
  • the processor 601 may be a single core or multi-core central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated systems configured to implement the embodiments of the present invention. Circuit.
  • CPU central processing unit
  • ASIC application specific integrated circuit
  • the memory 602 can be a high speed RAM memory or a nonvolatile memory.
  • non-volatile memory such as at least one disk storage.
  • Memory 602 is used to store program 605.
  • the program 605 may include program code, where the program code includes a computer execution instruction.
  • the processor 601 runs the program 605 to execute the following instructions:
  • the subcarrier test sequence includes at least one masking frequency point, and shielding the subcarrier signal corresponding to the frequency at the masking frequency point ;
  • the multi-line crosstalk test apparatus further performs the communication method shown in FIG. 2-4 above according to the instruction, and details are not described herein.
  • FIG. 7 is a schematic diagram of a multi-line crosstalk test system according to the embodiment. As shown in FIG. 7, the system includes: a spectrum management center unit 701, a plurality of transmitting ends 702 corresponding to the tested lines, and a receiving end 703.
  • the spectrum management center unit 701 configures a corresponding subcarrier test sequence for each of the plurality of tested lines, where the subcarrier test sequence includes at least one masking frequency point, and the masking frequency point is shielded. A subcarrier signal of the corresponding frequency is transmitted.
  • the transmitting end 702 of each tested line loads the subcarrier test sequence corresponding to each tested line, and sends it to the corresponding receiving end 703 via each of the tested lines.
  • the spectrum management center unit 701 collects the operation parameter information of each of the tested lines, and calculates the operation parameter information corresponding to the plurality of measured lines, and calculates between the two tested lines. Crosstalk level factor.
  • the spectrum management center unit 701 When configuring the subcarrier test sequence, the spectrum management center unit 701 first acquires the number of lines K of the plurality of tested lines, and then sets the masked frequency points for the K lines to be tested, and generates K different subcarriers. a test sequence, wherein the number of the masking frequency points set in at least one of the subcarrier test sequences is greater than or equal to the number of lines ⁇ .
  • the spectrum management center unit 701 can also perform the foregoing communication method shown in FIG. 2-4, and details are not described herein.
  • the multi-line crosstalk test method, device and system provided by the present invention use tone b lackout to set shielding frequency points of different types of subcarriers, and construct different subcarrier test sequences, The uncorrelation of the sequence calculates the crosstalk level coefficient between the two lines to be tested. Only one subcarrier test sequence needs to be transmitted once on each line to be tested. It can test multiple lines at the same time, which can be fast and accurate. The crosstalk test is completed, and the tested line can work normally, which has little impact on the user's business.
  • RAM random access memory
  • ROM read-only memory
  • EEPROM electrically programmable ROM
  • EEPROM electrically erasable programmable ROM
  • registers hard disk, removable disk, CD-ROM, or technical field Any other form of storage medium known.

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  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

L'invention concerne un procédé, un dispositif et un système d'essai de diaphonie de lignes multiples. Le procédé consiste : à configurer la séquence d'essai de sous-porteuses correspondantes pour chacune des lignes multiples essayées, ladite séquence d'essai de sous-porteuses comportant au moins un point de fréquence de protection où l'émission du signal des sous-porteuses de la fréquence correspondante est protégée ; à commander l'extrémité émettrice de chaque ligne essayée afin de téléverser une séquence d'essai de sous-porteuses correspondantes vers chaque ligne essayée et à envoyer la séquence à l'extrémité émettrice correspondante par l'intermédiaire de chaque ligne essayée ; à rassembler des informations sur les paramètres de fonctionnement de chaque ligne essayée ; à calculer le coefficient du niveau de diaphonie entre chaque paire de lignes multiples essayées en fonction des informations de paramètres de fonctionnement reçues par l'intermédiaire des lignes multiples essayées. La présente invention peut à la fois essayer des lignes multiples et effectuer avec rapidité et précision l'essai de diaphonie, alors que la ligne essayée peut encore fonctionner normalement, ayant ainsi peu d'incidence sur le service de l'utilisateur.
PCT/CN2012/088077 2012-12-31 2012-12-31 Procédé, dispositif et système d'essai de diaphonie de lignes multiples WO2014101202A1 (fr)

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US9985685B2 (en) 2014-09-26 2018-05-29 Futurewei Technologies, Inc. Power spectrum density optimization
CN104865441B (zh) * 2015-05-27 2017-11-10 中国科学院电工研究所 一种串扰频谱计算方法
CN108347393B (zh) * 2017-01-22 2020-11-06 华为技术有限公司 交叉线序的处理方法、设备和系统

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