CN101312360A - Filtering method and apparatus thereof, and crosstalk counteracting method and system thereof - Google Patents
Filtering method and apparatus thereof, and crosstalk counteracting method and system thereof Download PDFInfo
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Abstract
The invention discloses a filtering method and a device thereof, a crosstalk interference cancellation method and a system thereof, which is used to reduce computational complexity in the crosstalk interference cancellation process. The filtering method comprises steps of deserializing input time domain signals, converting the time domain signals which are deserialized to frequency domain signals via a time-frequency conversion, multiplying each frequency domain signal by a relative filtering parameter to obtain a frequency domain filtering result, converting the frequency domain filtering results to the time domain filtering results via frequency-time conversion, and then obtaining crosstalk interference signals via parallel-serial conversion of the time domain filtering results. The invention relatively provides a filter device, a crosstalk interference cancellation method and a crosstalk interference cancellation system. The filtering method and a device thereof and a crosstalk interference cancellation method and a system thereof can effectively reduce computational complexity in the crosstalk interference cancellation process and increase system performance.
Description
Technical field
The present invention relates to the communications field, relate in particular to a kind of filtering method and device thereof and cross talk counteracting method and system thereof.
Background technology
Digital Subscriber Line (DSL, Digital Subscriber Line) technology is a kind of twisted pair telephone that passes through, be unshielded twisted pair (UTP, Unshielded Twist Pair) carries out the high speed transmission technology of transfer of data, comprise ADSL (Asymmetric Digital Subscriber Line) (ADSL, Asymmetrical Digital Subscriber Line), Very-high-speed Digital Subscriber Line (VDSL, Very-high-bit-rate Digital Subscriber Line), based on integrated services digital network (ISDN, Integrated Services Digital Network) number of users word line (IDSL, ISDN Digital Subscriber Line) and single-line high speed digital subscriber line (SHDSL, Single-pair High-bit-rate Digital Subscriber Line) etc.
The raising of the frequency band that uses along with various digital user line technologies (xDSL) is crosstalked, and especially the cross-interference issue of high band shows to such an extent that become increasingly conspicuous.Because xDSL up-downgoing channel adopts frequency division multiplexing, near-end cross (NEXT) does not produce too big harm to the performance of system; But far-end cross talk (FEXT) can have a strong impact on the transmission performance of circuit, as shown in Figure 1.When having the multichannel user all to require to open the xDSL business in a bundle cable, can be because far-end cross talk (FEXT) makes that some line speeds are low, unstable properties even can not open etc., finally cause the line activation rate of DSL couple in multiplexer (DSLAM, DSL AccessMultiplexer) lower.
Have a kind of vectored-DSL technology to be used to offset the interference of FEXT in the prior art, as shown in Figure 2, the crosstalk counteracting flow process of prior art comprises:
Recipient's 201 receiving digital signals;
The frequency domain error that digital signal processor (DSP, Digital Signal Processor) 202 calculates in the digital signal that receives, error interception module 203 is converted to described frequency domain error signal the time domain error signal and intercepts some time domain error signals;
Lowest mean square (LMS, Least Mean Square) ERROR ALGORITHM module 206 is according to the time domain error signal of intercepting and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking;
The time-domain signal of 204 pairs of all sides of crosstalking of filter carries out convolution algorithm and realizes filtering, obtains the time domain crosstalk signal;
According to the principle of convolution algorithm as can be known, if total N signal, then the convolutional calculation amount of each signal is N, so the convolutional calculation amount of N signal is N
2, promptly the amount of calculation that N signal carried out filtering is N
2
In addition, need to use filtering parameter w (n) in the process of filtering, the value of n is [1, N], and this parameter realizes upgrading in LMS ERROR ALGORITHM module, and the iterative formula of renewal is:
w(n+1)＝w(n)-μe(n)*x(n)
Wherein, μ is a step parameter, and e (n) is the capable row vector of n, and x (n) is the matrix of a n * n, so be N to the amount of calculation of the renewal of filtering parameter w (n)
2+ N.
In the above-mentioned prior art, when the numerical value of N increases, overall amount of calculation will be big with square multiplication, so the filtering method amount of calculation of prior art is excessive, influence systematic function and realizability.
Summary of the invention
The technical problem that the embodiment of the invention will solve provides a kind of filtering method and device and cross talk counteracting method and system thereof, is used to reduce computation complexity, improves systematic function.
The filtering method that the embodiment of the invention provides comprises: the time-domain signal of the side of crosstalking input is gone here and there and changed; To be converted to frequency-region signal through the time-domain signal of described string and conversion by time-frequency conversion; Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result; By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result; Described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
The cross talk counteracting method that the embodiment of the invention provides comprises: calculate the frequency domain error in the digital signal that receives; Conversion is converted to the time domain error signal with the frequency domain error signal during by frequency, and intercepts some time domain error signals from described time domain error signal; According to time domain error signal that receives and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking; To going here and there from the time-domain signal of the side's of crosstalking reception and changing; To be converted to frequency-region signal through the time-domain signal of described string and conversion by time-frequency conversion; Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result; By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result; Described time-domain filtering result carried out and go here and there conversion back output crosstalk signal; The described crosstalk signal of deletion from the digital signal that receives.
The filter that the embodiment of the invention provides comprises: string and converting unit are used for the time-domain signal that the side of crosstalking imports is gone here and there and changed; The time-frequency conversion unit is used for described time-domain signal through string and conversion is converted to frequency-region signal; Multiplication unit, being used for each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtains the frequency domain filtering result; The frequency-time domain transformation unit is used for described frequency domain filtering result is converted to the time-domain filtering result; Parallel serial conversion unit is used for described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
The crosstalk counteracting system that the embodiment of the invention provides comprises: receiving terminal is used for receiving digital signals; Digital signal processing device is used for calculating the frequency domain error that described digital signal exists; Error conversion interception unit is used for described frequency domain error signal is converted to the time domain error signal and intercepts some time domain error signals from described time domain error signal; Algorithm unit is used for according to some time domain error signals of error conversion interception unit intercepting and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking; Filter, be used for going here and there from the time-domain signal of the side's of crosstalking reception and changing, by time-frequency conversion described time-domain signal through string and conversion is converted to frequency-region signal, each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result, by frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result, and described time-domain filtering result carried out and goes here and there conversion back output crosstalk signal; The crosstalk counteracting unit is used for the described crosstalk signal of digital signal deletion that receives from described.
As can be seen from the above technical solutions, the embodiment of the invention has the following advantages:
Because the process to the filtering of signal in the embodiment of the invention is: 2N point time-domain signal is carried out a time-frequency conversion (with fast fourier transform (FFT, Fast Fourier Transform) be example), a product calculation, a frequency-time domain transformation is (with contrary fast fourier transform (IFFT, Inverse Fast FourierTransform) be example), so the amount of calculation of filtering is 2Nlog
2(2N)+4N+2Nlog
2(2N)=4Nlog
2N+8N, and under general actual conditions, for more accurate counteracting is crosstalked, the value of N is minimum to be 128, thus can be by relatively learning, the amount of calculation of filtering method reduces in the embodiment of the invention, has reduced computation complexity, has improved systematic function.
Description of drawings
Fig. 1 is a far-end cross talk schematic diagram in the prior art;
Fig. 2 is a crosstalk counteracting model schematic diagram in the prior art;
Fig. 3 is a filtering method embodiment flow chart in the embodiment of the invention;
Fig. 4 upgrades the first embodiment flow chart for filtering parameter in the embodiment of the invention filtering method;
Fig. 5 upgrades the second embodiment flow chart for filtering parameter in the embodiment of the invention filtering method;
Fig. 6 is a cross talk counteracting method embodiment flow chart in the embodiment of the invention;
Fig. 7 is a filter embodiment schematic diagram in the embodiment of the invention;
Fig. 8 is a crosstalk counteracting system embodiment schematic diagram in the embodiment of the invention;
Fig. 9 moves schematic diagram for algorithm unit embodiment in the embodiment of the invention crosstalk counteracting system.
Embodiment
The embodiment of the invention provides a kind of filtering method and device and cross talk counteracting method and system thereof, is used to reduce computation complexity, improves systematic function.
The embodiment of the invention can be applicable in the far-end cross talk counteracting technology, in the following embodiments, be example all to offset far-end cross talk, in addition, in the following embodiments, with the example of FFT as time-frequency conversion, with the example of IFFT as frequency-time domain transformation, in addition, in the following embodiments with the example of DSP as digital signal processing device, being understandable that, can be other devices that are used for processing digital signal equally.
See also Fig. 3, filtering method embodiment comprises in the embodiment of the invention:
301, filter receives the time frequency signal of input;
Filter receives time-domain signal from the side of crosstalking.
302, time-domain signal is gone here and there and change;
The filtering mode of mainly taking in the embodiment of the invention is a frequency domain filtering, and different with time-domain filtering is that frequency domain filtering carries out piecemeal by N point signal to be handled.So must consider " smearing " of channel, promptly at k-1 piece when the channel to the influence of k block signal.
Under the situation of length less than N of the impulse response of supposing channel, the time-domain signal to two block lengths carries out Filtering Processing at every turn, and abandons the result of last part in filtering output.
So in the present embodiment, after N point time-domain signal gone here and there and change, unite the N point time-domain signal that a time period stores simultaneously and be for further processing as time-domain signal together.
303, time-domain signal is converted to frequency-region signal;
The time-domain signal that 2N is ordered carries out the FFT processing, obtains N point frequency domain signal X (k), wherein
X(k)＝diag{FFT[x(kN-N)，...，x(kN-1)，x(kN)，...，x(kN+N-1)]}。
304, upgrade filtering parameter;
For carrying out frequency domain filtering, need upgrade filtering parameter, concrete renewal process will describe in detail in the embodiment of back.
305, carry out frequency domain filtering;
N point frequency domain signal X (k) and filtering parameter W (k) multiplied each other carry out frequency domain filtering.
306, many line filter results that crosstalk are gathered;
If many circuits of crosstalking are arranged, then every circuit is carried out frequency domain filtering, obtain frequency domain filtering result separately, and all frequency domain filtering results are gathered obtain total frequency domain filtering result.
307, the frequency domain filtering result is converted to the time-domain filtering result;
By IFFT the frequency domain filtering result is converted to the time-domain filtering result, promptly
y
T(k)＝IFFT[X(k)*W(k)]
308, the time-domain filtering result is carried out and go here and there the conversion and output.
Abandon the time-domain filtering result that preceding N is ordered among the time-domain filtering result according to putting in order, and remaining time-domain filtering result is carried out and go here and there being converted to crosstalk signal, finish filtering.
Carry out Filtering Processing owing to when frequency domain filtering, considered " smearing " of signal at each time-domain signal in the present embodiment, and in filtering output, abandon the result of last part, so guaranteed the performance of crosstalk counteracting two block lengths;
In addition, owing to consider and to have many circuits of crosstalking, so can the frequency domain filtering result of many circuits of crosstalking be gathered, being converted to the time-domain filtering result afterwards further handles, when circuit is crosstalked on the N road, can save the amount of calculation of N-1 IFFT, so can further reduce overall amount of calculation.
Be understandable that, not execution in step 304 and/or step 306 in the present embodiment, promptly when filtering parameter is upgraded by other flow process or method, then do not need in the present embodiment again it to be upgraded, only need directly read and get final product, in the method prior art of concrete renewal filtering parameter many kinds are arranged, repeat no more herein; Having only the one tunnel not execution in step 306 of crosstalking under the situation of circuit, perhaps ought not consider situation about gathering, when carrying out the IFFT conversion alone at the frequency domain filtering result of every the circuit of crosstalking, also execution in step 306 not.
Introduce the process of in the embodiment of the invention filtering parameter being upgraded below in detail, the renewal to filtering parameter in the embodiment of the invention has following two kinds of situations according to the crosstalk counteracting pattern:
One, up crosstalk counteracting pattern:
See also Fig. 4, filtering parameter upgrades first embodiment and comprises in the embodiment of the invention filtering method:
401, the time domain error signal of local side apparatus feedback is mended 0;
In the present embodiment, local side apparatus (for example DSLAM) feedback frequency domain error signal, this frequency domain error signal is carried out the IFFT conversion obtain the time domain error signal, and intercepting N point time domain error signal is imported algorithm unit from the time domain error signal that obtains, and algorithm unit is mended into N 0 signal the N point time domain error signal that receives and obtained 2N point time domain error signal.
402, the time domain error signal is converted to the frequency domain error signal;
2N point time domain error signal is carried out FFT handle, obtain N point frequency domain error signal
403, the frequency-region signal of the side's of crosstalking input is got conjugation and obtain conjugate;
By the FFT conversion will the side of crosstalking the time-domain signal of input be converted to frequency-region signal, and frequency-region signal got conjugation obtain conjugate.
404, the product with frequency domain error signal and conjugate is converted to result in time domain;
P(k)＝IFFT[X
H(k)*E(k)]
405, result in time domain is converted to frequency domain parameter;
In the present embodiment, this step specifically comprises:
Abandon by back N the signal that puts in order above-mentioned result in time domain, and mend into obtaining time domain parameter with 0 signal;
Time domain parameter is carried out the FFT processing obtain interim frequency domain parameter;
With the product of interim frequency domain parameter and step parameter as frequency domain parameter.
406, to frequency domain parameter and the summation of last filtering parameter.
With last filtering parameter and frequency domain parameter sum as this filtering parameter.
What present embodiment was described is the filtering parameter update method of up crosstalk counteracting pattern, introduce the filtering parameter update method of descending crosstalk counteracting pattern below, be that with the update method main distinction of up crosstalk counteracting pattern the mode and the error signal source of feeding back are different.
Two, descending crosstalk counteracting pattern:
See also Fig. 5, filtering parameter upgrades second embodiment and comprises in the embodiment of the invention filtering method:
501, the frequency domain error signal with feedback is converted to the time domain error signal;
In the present embodiment, the frequency domain error signal that customer premises equipment, CPE (CPE, Customer Premises Equipment) is fed back is converted to the time domain error signal, and intercepts N point time domain error signal from the time domain error signal.
502, the time domain error signal is mended 0;
To the N point time domain error signal that receives, benefit obtains 2N point time domain error signal after going into N 0 signal.
503, the time domain error signal is converted to the frequency domain error signal;
2N point time domain error signal is carried out FFT handle, obtain N point frequency domain error signal
504, the frequency-region signal of the side's of crosstalking input is got conjugation and obtain conjugate;
By the FFT conversion will the side of crosstalking the time-domain signal of input be converted to frequency-region signal, and frequency-region signal got conjugation obtain conjugate.
505, the product with frequency domain error signal and conjugate is converted to result in time domain;
P(k)＝IFFT[X
H(k)*E(k)]
506, result in time domain is converted to frequency domain parameter;
In the present embodiment, this step specifically comprises:
Abandon by back N the signal that puts in order above-mentioned result in time domain, and mend into obtaining time domain parameter with 0 signal;
Time domain parameter is carried out the FFT processing obtain interim frequency domain parameter;
With the product of interim frequency domain parameter and step parameter as frequency domain parameter.
507, to frequency domain parameter and the summation of last filtering parameter.
With last filtering parameter and frequency domain parameter sum as this filtering parameter.
Introduced two kinds of methods of upgrading filtering parameter above, made the technical scheme in the embodiment of the invention both can be applied to row mode, can be applied to downlink mode again, so improved the accommodation of technical scheme in the embodiment of the invention.
Introduce a kind of cross talk counteracting method based on above-mentioned filtering method below, see also Fig. 6, cross talk counteracting method embodiment comprises in the embodiment of the invention:
601, receiving terminal receiving digital signals;
The signal that receives comprises: as the circuit received signal of the side of crosstalking with as the quilt circuit received signal of the side of crosstalking.Here received the influence of the crosstalk signal that the square signal of crosstalking produces because of coupling in the line by the circuit received signal of the side of crosstalking.
Receiving terminal receives after the digital signal, and the crosstalk counteracting unit carries out once unified crosstalk counteracting to every N signal, promptly considers " smearing " of channel, all needs to use last N point time-domain signal at every turn, and stores this N point time-domain signal.
602, calculate the frequency domain error that exists in the digital signal;
DSP calculates the frequency domain error that exists in the digital signal according to the digital signal that receives.
Wherein, consistent in the process that DSP calculates the frequency domain error that exists in the digital signal and the prior art, idiographic flow repeats no more.
603, the frequency domain error signal is converted to the time domain error signal;
Error conversion interception unit is converted to the time domain error signal with the frequency domain error signal that DSP calculates.
604, the some time domain error signals of intercepting;
Error conversion interception unit intercepts the input of N serial time domain error signal as next step from the time domain error signal after the conversion.
The input signal that the principle of intercepting is with algorithm unit needs aligns on time domain synchronously.
605, according to the frequency-region signal of the side's of crosstalking input and the time domain error signal calculation filtering parameter of error conversion interception unit input;
For carrying out frequency domain filtering, need upgrade filtering parameter, concrete renewal process describes in detail in the above embodiments, repeats no more herein.
606, to going here and there from the time-domain signal of the side's of crosstalking reception and changing;
The filtering mode of mainly taking in the embodiment of the invention is a frequency domain filtering, and different with time-domain filtering is that frequency domain filtering carries out piecemeal by N point signal to be handled.So must consider " smearing " of channel, promptly at k-1 piece when the channel to the influence of k block signal.
Under the situation of length less than N of the impulse response of supposing channel, the time-domain signal to two block lengths carries out Filtering Processing at every turn, and abandons the result of last part in filtering output.
So in the present embodiment, N point time-domain signal is gone here and there and changed, unite the N point time-domain signal that a time period stores simultaneously and be for further processing as time-domain signal together.
607, time-domain signal is converted to frequency-region signal;
Time-domain signal to 2N length carries out the FFT processing, obtains N point frequency domain signal X (k), wherein
X(k)＝diag{FFT[x(kN-N)，...，x(kN-1)，x(kN)，...，x(kN+N-1)]}。
608, carry out frequency domain filtering;
N point frequency domain signal X (k) and filtering parameter W (k) multiplied each other carry out frequency domain filtering.
609, many line filter results that crosstalk are gathered;
If many circuits of crosstalking are arranged, then every circuit is carried out frequency domain filtering, obtain frequency domain filtering result separately, and all frequency domain filtering results are gathered obtain total frequency domain filtering result.
610, the frequency domain filtering result is converted to the time-domain filtering result;
By IFFT the frequency domain filtering result is converted to the time-domain filtering result, promptly
y
T(k)＝IFFT[X(k)*W(k)]
611, the time-domain filtering result is carried out and go here and there the conversion and output;
Abandon the time-domain filtering result that preceding N is ordered among the time-domain filtering result according to putting in order, and remaining time-domain filtering result is carried out and go here and there being converted to crosstalk signal, finish filtering.
612, from digital signal, delete crosstalk signal.
The crosstalk counteracting unit is deleted above-mentioned crosstalk signal and is finished the crosstalk counteracting flow process from the digital signal that receives.Under descending crosstalk counteracting pattern, send again after need adding the crosstalk signal component of estimation to primary signal.
Carry out Filtering Processing owing to when frequency domain filtering, considered " smearing " of signal at each time-domain signal in the present embodiment, and in filtering output, abandon the result of last part, so guaranteed the performance of crosstalk counteracting two block lengths;
In addition, owing to consider and to have many circuits of crosstalking, so can the frequency domain filtering result of many circuits of crosstalking be gathered, being converted to the time-domain filtering result afterwards further handles, when circuit is crosstalked on the N road, can save the amount of calculation of N-1 IFFT, so can further reduce overall amount of calculation.
Be understandable that, not execution in step 605 and/or step 609 in the present embodiment, promptly when filtering parameter is upgraded by other flow process or method, then do not need in the present embodiment again it to be upgraded, only need directly read and get final product, in the method prior art of concrete renewal filtering parameter many kinds are arranged, repeat no more herein; Having only the one tunnel not execution in step 609 of crosstalking under the situation of circuit, perhaps ought not consider situation about gathering, when carrying out the IFFT conversion alone at the frequency domain filtering result of every the circuit of crosstalking, also execution in step 609 not.
According to above-mentioned cross talk counteracting method embodiment as can be known, overall cross talk counteracting method amount of calculation comprises three parts:
One, error conversion interception unit amount of calculation:
According to the error of each tone on the frequency domain, obtain the time domain error signal by the IFFT processing.The time domain error signal here is actual, and what use is the N point signal that intercepts out from the time domain error signal.The input signal that the principle of intercepting is with algorithm unit needs aligns on time domain synchronously.
Supposing the system has used 4096 tone altogether, and the complex multiplication amount of calculation of then whenever carrying out this module in filtering parameter iterative process is to calculate by 4096 IFFT:
This a part of amount of calculation is the same with the amount of calculation of this part in the prior art, so do not consider the scope into comparison.
Two, filter amount of calculation:
In the present embodiment, the amount of calculation of filter is mainly: 2N signal carried out a FFT conversion, and a product calculation, an IFFT conversion is so the amount of calculation of filtering is 2Nlog
2(2N)+4N+2Nlog
2(2N)=4Nlog
2N+8N.
Three, filtering parameter update calculation amount:
In the present embodiment, the amount of calculation that filtering parameter upgrades comprises 3 times time-frequency conversion (FFT), the complex multiplication that N is ordered, the plural number that N is ordered and the multiplication of real number.
So whenever carry out the amount of calculation of a filtering parameter renewal process be:
3*2Nlog
2(2N)+4N+2N＝6Nlog
2N+12N。
So the summation of filter amount of calculation and filtering parameter update calculation amount is in the present embodiment
4Nlog
2N+8N+6Nlog
2N+12N＝10Nlog
2N+20N。
The summation of filter amount of calculation and filtering parameter update calculation amount is 2N in the prior art
2+ N, and the value of N generally can be bigger, usually minimum is 128, so, in the time of N=128, the arithmetic speed of technical scheme is 2.8 times of arithmetic speed of technical scheme in the prior art in the present embodiment, and when N=1024, the arithmetic speed of technical scheme is about 17 times of arithmetic speed of technical scheme in the prior art in the present embodiment, in addition, if consider the situation that the frequency domain filtering result to many circuits of crosstalking gathers, then the arithmetic speed of technical scheme will further improve in the present embodiment.
Introduce the device in the embodiment of the invention below, see also Fig. 7, filter comprises in the embodiment of the invention:
String and converting unit 701 are used for the time-domain signal that the side of crosstalking imports is gone here and there and changed;
Time-frequency conversion unit 702 is used for described time-domain signal through string and conversion is converted to frequency-region signal;
Frequency-time domain transformation unit 704 is used for described frequency domain filtering result is converted to the time-domain filtering result;
Parallel serial conversion unit 705 is used for described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
Filtering parameter acquiring unit 706 is used to obtain the filtering parameter after the renewal.
See also Fig. 8, the crosstalk counteracting system comprises in the embodiment of the invention:
Receiving terminal 801 is used for receiving digital signals;
Digital signal processing device 802 is used for calculating the frequency domain error that digital signal exists;
Error conversion interception unit 803 is used for described frequency domain error signal is converted to the time domain error signal and intercepts some time domain error signals from described time domain error signal;
Below the concrete operational process of the algorithm unit in the embodiment of the invention 804 is carried out, see also Fig. 9, algorithm unit embodiment operational process comprises in the embodiment of the invention:
The time domain error signal is mended 0 to be handled;
By the FFT conversion time domain error signal is converted to the frequency domain error signal;
The frequency-region signal of the side of crosstalking input is got conjugation obtain conjugate, and the product of frequency domain error signal and conjugate is converted to result in time domain by IFFT;
Abandon by back N the signal that puts in order above-mentioned result in time domain, and mend into obtaining time domain parameter with 0 signal;
Time domain parameter is carried out the FFT processing obtain interim frequency domain parameter;
With the product of interim frequency domain parameter and step parameter as frequency domain parameter;
Frequency domain parameter and the summation of last filtering parameter are obtained this filtering parameter.
One of ordinary skill in the art will appreciate that all or part of step that realizes in the foregoing description method is to instruct relevant hardware to finish by program, described program can be stored in a kind of computer-readable recording medium, this program comprises the steps: the time-domain signal that the side of crosstalking imports is gone here and there and changed when carrying out; By time-frequency conversion described time-domain signal through string and conversion is converted to frequency-region signal; Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result; By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result; Described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
Or
The receiving terminal receiving digital signals; Digital signal processing device calculates the frequency domain error according to described digital signal; Conversion is converted to the time domain error signal with described frequency domain error signal during by frequency; Intercept some time domain error signal input algorithm units; Algorithm unit is according to time domain error signal that receives and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking; Filter is gone here and there to the time-domain signal that receives from the side of crosstalking and is changed; By time-frequency conversion described time-domain signal through string and conversion is converted to frequency-region signal; Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result; By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result; Described time-domain filtering result carried out and go here and there conversion back output crosstalk signal; The described crosstalk signal of deletion from the described digital signal that receives.
The above-mentioned storage medium of mentioning can be a read-only memory, disk or CD etc.
More than a kind of filtering method provided by the present invention and device thereof and cross talk counteracting method and system thereof are described in detail, for one of ordinary skill in the art, thought according to the embodiment of the invention, part in specific embodiments and applications all can change, in sum, this description should not be construed as limitation of the present invention.
Claims (11)
1, a kind of filtering method is characterized in that, comprising:
The time-domain signal of the side of crosstalking input is gone here and there and changed;
To be converted to frequency-region signal through the time-domain signal of described string and conversion by time-frequency conversion;
Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result;
By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result;
Described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
2, filtering method according to claim 1 is characterized in that, described time-domain signal to the side of crosstalking input is gone here and there and the step changed comprises:
The N point time-domain signal of this input of the side of crosstalking is gone here and there and changed;
To merge into 2N point time-domain signal through the N point time-domain signal of string and conversion and the N point time-domain signal of storage of the last time period;
Describedly the described step that is converted to frequency-region signal through the time-domain signal of string and conversion is comprised by time-frequency conversion:
By time-frequency conversion described 2N point time-domain signal is converted to N point frequency-region signal;
Described the time-domain filtering result is carried out and go here and there the conversion step before comprise:
Abandon the time-domain filtering result that preceding N is ordered according to putting in order.
3, filtering method according to claim 2 is characterized in that, described each frequency-region signal is multiplied each other with corresponding filtering parameter respectively comprises before the step that obtains the frequency domain filtering result:
Upgrade filtering parameter.
4, filtering method according to claim 3 is characterized in that, the step of described renewal filtering parameter comprises:
The N point time domain error signal of local side apparatus feedback mended into N point 0 signal obtain 2N point time domain error signal;
By time-frequency conversion described time domain error signal is converted to the frequency domain error signal;
By time-frequency conversion will the side of crosstalking the time-domain signal of input be converted to frequency-region signal, and described frequency-region signal got conjugation obtain conjugate;
By frequency-time domain transformation the product of described frequency domain error signal and described conjugate is converted to result in time domain;
Obtain time domain parameter according to putting in order with the 0 back N number value that substitutes described result in time domain;
By time-frequency conversion described time domain parameter is converted to interim frequency domain parameter;
With the product of described interim frequency domain parameter and step parameter as frequency domain parameter;
With described frequency domain parameter and last filtering parameter sum as this filtering parameter.
5, filtering method according to claim 3 is characterized in that, the step of described renewal filtering parameter comprises:
By frequency-time domain transformation the frequency domain error signal that customer premises equipment, CPE feeds back is converted to the time domain error signal;
Described time domain error signal mended into N point 0 signal obtain 2N point time domain error signal;
By time-frequency conversion described time domain error signal is converted to the frequency domain error signal;
By time-frequency conversion will the side of crosstalking the time-domain signal of input be converted to frequency-region signal, and described frequency-region signal got conjugation obtain conjugate;
By frequency-time domain transformation the product of described frequency domain error signal and described conjugate is converted to result in time domain;
Obtain time domain parameter according to putting in order with the 0 back N number value that substitutes described result in time domain;
By time-frequency conversion described time domain parameter is converted to interim frequency domain parameter;
With the product of described interim frequency domain parameter and step parameter as frequency domain parameter;
With described frequency domain parameter and last filtering parameter sum as this filtering parameter.
6, according to each described filtering method in the claim 1 to 5, it is characterized in that, describedly comprise before by frequency-time domain transformation described frequency domain filtering result being converted to time-domain filtering result's step:
The frequency domain filtering result of many circuits of crosstalking gathered obtain total frequency domain filtering result;
Describedly the step that described frequency domain filtering result is converted to the time-domain filtering result is comprised by frequency-time domain transformation:
By frequency-time domain transformation described total frequency domain filtering result is converted to total time-domain filtering result.
7, a kind of cross talk counteracting method is characterized in that, comprising:
Frequency domain error in the digital signal that calculating receives;
Conversion is converted to the time domain error signal with the frequency domain error signal during by frequency, and intercepts some time domain error signals from described time domain error signal;
According to time domain error signal that receives and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking;
To going here and there from the time-domain signal of the side's of crosstalking reception and changing;
To be converted to frequency-region signal through the time-domain signal of described string and conversion by time-frequency conversion;
Each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result;
By frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result;
Described time-domain filtering result carried out and go here and there conversion back output crosstalk signal;
The described crosstalk signal of deletion from the digital signal that receives.
8, filtering method according to claim 7 is characterized in that, described filter comprises the step of going here and there from the time-domain signal of the side's of crosstalking reception and change:
The N point time-domain signal of this input of the side of crosstalking is gone here and there and changed;
To merge into 2N point time-domain signal through the N point time-domain signal of string and conversion and the N point time-domain signal of storage of the last time period;
Describedly the described step that is converted to frequency-region signal through the time-domain signal of string and conversion is comprised by time-frequency conversion:
By time-frequency conversion described 2N point time-domain signal is converted to N point frequency-region signal;
Described the time-domain filtering result is carried out and go here and there the conversion step before comprise:
Abandon the time-domain filtering result that preceding N is ordered according to putting in order.
9, a kind of filter is characterized in that, comprising:
String and converting unit are used for the time-domain signal that the side of crosstalking imports is gone here and there and changed;
The time-frequency conversion unit is used for described time-domain signal through string and conversion is converted to frequency-region signal;
Multiplication unit, being used for each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtains the frequency domain filtering result;
The frequency-time domain transformation unit is used for described frequency domain filtering result is converted to the time-domain filtering result;
Parallel serial conversion unit is used for described time-domain filtering result carried out and goes here and there obtaining crosstalk signal after the conversion.
10, filter according to claim 9 is characterized in that, described filter also comprises:
The filtering parameter acquiring unit is used to obtain the filtering parameter after the renewal.
11, a kind of crosstalk counteracting system is characterized in that, comprising:
Receiving terminal is used for receiving digital signals;
Digital signal processing device is used for calculating the frequency domain error that described digital signal exists;
Error conversion interception unit is used for described frequency domain error signal is converted to the time domain error signal and intercepts some time domain error signals from described time domain error signal;
Algorithm unit is used for according to some time domain error signals of error conversion interception unit intercepting and the frequency-region signal calculation of filtered parameter that receives from the side of crosstalking;
Filter, be used for going here and there from the time-domain signal of the side's of crosstalking reception and changing, by time-frequency conversion described time-domain signal through string and conversion is converted to frequency-region signal, each frequency-region signal multiplied each other with corresponding filtering parameter respectively obtain the frequency domain filtering result, by frequency-time domain transformation described frequency domain filtering result is converted to the time-domain filtering result, and described time-domain filtering result carried out and goes here and there conversion back output crosstalk signal;
The crosstalk counteracting unit is used for the described crosstalk signal of digital signal deletion that receives from described.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107645461A (en) * | 2016-07-22 | 2018-01-30 | 深圳超级数据链技术有限公司 | It is a kind of suitable for the modulator approach of OvXDM systems, device and OvXDM systems |
| CN108141202A (en) * | 2015-07-28 | 2018-06-08 | 弗劳恩霍夫应用研究促进协会 | Blockette adaptive frequency domain filter equipment including adaptation module and correction module |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| KR100864709B1 (en) * | 2002-05-30 | 2008-10-23 | 삼성전자주식회사 | OFDM Transmitter capable of improving the quality of receiving and a method processing OFDM signal thereof |
| CN1707613A (en) * | 2005-05-27 | 2005-12-14 | 曲哲 | Collecting apparatus and method for noise insulation audio frequency |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108141202A (en) * | 2015-07-28 | 2018-06-08 | 弗劳恩霍夫应用研究促进协会 | Blockette adaptive frequency domain filter equipment including adaptation module and correction module |
| CN108141202B (en) * | 2015-07-28 | 2021-10-29 | 弗劳恩霍夫应用研究促进协会 | Partitioned block frequency domain adaptive filter apparatus including adaptive module and correction module |
| CN107645461A (en) * | 2016-07-22 | 2018-01-30 | 深圳超级数据链技术有限公司 | It is a kind of suitable for the modulator approach of OvXDM systems, device and OvXDM systems |
| CN107645461B (en) * | 2016-07-22 | 2021-09-24 | 广东恒域科技股份有限公司 | Modulation method and device suitable for OvXDM system and OvXDM system |
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| CN101312360B (en) | 2012-08-29 |
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