CN107852385A

CN107852385A - A kind of line speed method for improving and device

Info

Publication number: CN107852385A
Application number: CN201580081495.8A
Authority: CN
Inventors: 殷慧; 孙方林
Original assignee: Huawei Technologies Co Ltd
Current assignee: Shanghai Pengbang Industrial Co ltd
Priority date: 2015-07-16
Filing date: 2015-07-16
Publication date: 2018-03-27
Anticipated expiration: 2035-07-16
Also published as: CN107852385B; WO2017008308A1

Abstract

The embodiments of the invention provide a kind of method of line speed lifting, in transmitting terminal, precoding coefficients P, (I) are obtained；Wherein H^‑1M bar twisted-pair feeder upper signal channel transmission matrixs H inverse matrix is represented, (II) is the diagonal matrix using the direct channels in the channel transfer matrices H as main diagonal element；Precoding is carried out to the signal to be sent on the M bars twisted-pair feeder using the precoding coefficients P；Signal to be sent after the precoding is sent；The embodiment of the present invention additionally provides a kind of device of line speed lifting.

Description

Line rate improving method and device

Technical Field

The invention relates to the field of data communication, in particular to a method and a device for improving line speed.

Background

Digital Subscriber Line (DSL) is a high-speed data transmission technology for transmission over telephone twisted Pair wires, such as Unshielded Twisted Pair (UTP). A DSL system has multiple DSL lines, and at present, multiple DSL accesses are usually provided by a DSL Access Multiplexer (DSLAM) for multiple Customer Premises Equipments (CPEs). However, due to the principle of electromagnetic induction, Crosstalk (Crosstalk) is generated between multiple signals accessing the DSLAM. As shown in fig. 1. Twisted pair lines have strong Far-end Crosstalk (FEXT) at high frequencies, and in order to cancel Crosstalk-induced noise, for example, Vectored DSL techniques may be used to cancel Far-end Crosstalk on multiple DSL lines. Without the use of Vector technology, most lines can only reach 20-30% of the rate at which a single line is active (i.e., the rate without crosstalk). However, if Vector technology is used, relatively high rates can be achieved on the line, but at best only about 95% of the rate without crosstalk can be achieved.

Disclosure of Invention

The embodiment of the invention provides a method and a device for improving the speed of a line, which are used for increasing the speed of the line.

In a first aspect, an embodiment of the present invention provides a method for increasing a line rate, including:

at the transmitting end, a precoding coefficient P is obtained, where H^-1The inverse matrix for representing the channel transmission matrix H on the M twisted pairs is a diagonal matrix which takes a direct channel in the channel transmission matrix H as a main diagonal element; Δ H_kIs divided by the kth main diagonal element by Δ h_kkBesides, the other elements are all matrixes of 0, wherein N represents the number of lines needing to adjust the transmission power, and N is more than or equal to 1 and less than or equal to M; and is a direct channel h with the line k_kkCross talk channel h between the phase differences of_kiArranging elements of a set formed after the elements are arranged from large to small according to amplitude values;

pre-coding the signals to be transmitted on the M twisted pairs by using the pre-coding coefficient P;

and sending out the pre-coded signal to be sent.

In a first possible implementation manner of the first aspect, the channel transmission matrix H on the M twisted pairs is represented as where a diagonal element H is_iiDirect channel, off diagonal element h representing line i_ijRepresenting a crosstalk channel of a line j to a line i, wherein i is more than or equal to 1 and less than or equal to M, j is more than or equal to 1 and less than or equal to M, and i is not equal to j; can be represented as wherein h_MMTo representA direct channel of line M; Δ H_kCan be expressed as

In combination with the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner, the Δ H_kIs obtained by the following method:

in the set of direct channels of line k and crosstalk channels of other lines of the M lines to line k, i.e. H_kIn the method, a direct channel h with the line k is searched_kkCross talk channel h between the phase differences of_kiForm a set S in which angle (h)_ki,h_kk) Representing a cross-talk channel h_kiAnd h_kkPhase difference; arranging the elements of the S according to the amplitude values from large to small to obtain the amplitude represented in the set; then obtaining Δ H by_k。

With reference to the first aspect, the first possible implementation manner of the first aspect, or the second possible implementation manner of the first aspect, in a third possible implementation manner, the method further includes,

obtaining an updated precoding coefficient P', where Δ H_gIs divided by the g-th main diagonal element by Δ h_ggBesides, the remaining elements are all matrices of 0, and the sum is the direct channel h with the line g_ggCross talk channel h between the phase differences of_giAnd arranging the elements of the formed set from large to small according to the amplitude values.

Pre-coding the signals to be transmitted on the M twisted pairs by using the P'; and sending out the pre-coded signal to be sent.

In a second aspect, an embodiment of the present invention provides an apparatus for increasing a line speed, including: a precoding coefficient acquisition unit 31, a precoder 32, and a transmitter 33;

the precoding coefficient obtaining unit 31 is configured to obtain a precoding coefficient P, where H is^-1The inverse matrix for representing the channel transmission matrix H on the M twisted pairs is a diagonal matrix which takes a direct channel in the channel transmission matrix H as a main diagonal element; Δ H_kIs divided by the kth main diagonal element by Δ h_kkBesides, the matrix with all the other elements being 0Wherein N represents the number of lines for which the transmission power needs to be adjusted, and N is greater than or equal to 1 and less than or equal to M; and is a direct channel h with the line k_kkCross talk channel h between the phase differences of_kiArranging elements of a set formed after the elements are arranged from large to small according to amplitude values;

the precoder 32 is configured to precode signals to be transmitted on the M twisted pairs by using the precoding coefficient P;

the transmitter 33 is configured to send out a signal to be sent after precoding.

In a first possible implementation manner of the second aspect, the channel transmission matrix H on the M twisted pairs is represented as

Wherein, diagonal element h_iiDirect channel, off diagonal element h representing line i_ijRepresenting a crosstalk channel of a line j to a line i, wherein i is more than or equal to 1 and less than or equal to M, j is more than or equal to 1 and less than or equal to M, and i is not equal to j; can be represented as wherein h_MMA direct channel representing line M; Δ H_kCan be expressed as

With reference to the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner, the precoding coefficient obtaining unit 31 is further configured to obtain Δ H_kThe method specifically comprises the following steps:

With reference to the second aspect, the first possible implementation manner of the second aspect, or the second possible implementation manner of the second aspect, in a third possible implementation manner, the precoding coefficient obtaining unit 31 obtains an updated precoding coefficient P 'and then sends the updated precoding coefficient P' to a precoder, where Δ H is Δ H_gIs except the g-th main diagonal elementIs Δ h_ggBesides, the remaining elements are all matrices of 0, and the sum is the direct channel h with the line g_ggCross talk channel h between the phase differences of_giAnd arranging the elements of the formed set from large to small according to the amplitude values.

And the precoder utilizes the P' to precode signals to be transmitted on the M twisted pairs.

In a third aspect, an embodiment of the present invention provides an apparatus for increasing a line rate, where the apparatus includes: a receiver 41, a processor 42 and a transmitter 43.

A receiver 41, configured to obtain a channel transmission matrix H on M twisted pairs; specifically, H is represented by

A processor 42 for calculating a precoding coefficient P, where H^-1The inverse matrix for representing the channel transmission matrix H on the M twisted pairs is a diagonal matrix which takes a direct channel in the channel transmission matrix H as a main diagonal element; Δ H_kIs divided by the kth main diagonal element by Δ h_kkBesides, the other elements are all matrixes of 0, wherein N represents the number of lines needing to adjust the transmission power, and N is more than or equal to 1 and less than or equal to M; and is a direct channel h with the line k_kkCross talk channel h between the phase differences of_kiArranging elements of a set formed after the elements are arranged from large to small according to amplitude values; pre-coding the signals to be transmitted on the M twisted pairs by using the pre-coding coefficient P;

and a transmitter 43, configured to send out the pre-coded signal to be sent.

In a first possible implementation manner of the third aspect, the channel transmission matrix H on the M twisted pairs is represented as

By adopting the scheme described in this embodiment, the specific precoding coefficient is utilized to precode the signal to be transmitted on the line, so that each line can increase a part of the transmission power while transmitting the signal on its own line at a certain power, and the speed of a certain line or a plurality of lines can be increased while suppressing the noise caused by crosstalk.

Drawings

Figure 1 is a schematic diagram of a network for multiple DSL access;

FIG. 2 is a schematic flow chart of a method according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an apparatus according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to eliminate crosstalk on a line, pre-compensation and the like can be performed on a transmission signal at a network side (CO side) according to crosstalk parameters fed back by a user side (namely, a CPE side), and the technique is called Vectoring (Vectoring); the device for performing vectorization processing is a Vectoring Control Entity (VCE) in the DSLAM. The existing Vectored DSL technology mainly utilizes the characteristic of joint transceiving at the DSLAM end, and uses a signal processing method to cancel FEXT interference. Finally, FEXT interference in each path of signal is eliminated. Corresponding to fig. 1, the shared channel between DSLAM and CPE downstream and upstream is denoted H, which is one of the subcarriers (tones) f in the frequency domain₀Above can be expressed in matrix form:

wherein, diagonal element h_iiDirect channel, off diagonal element h representing line i_ijRepresenting the crosstalk channel of line j to line i. By H_i＝[h_i1 h_i2 ... h_iM]Representing the set of direct channels of line i and crosstalk channels of other lines to line i, it can be seen that H_iThat is to say, the ith row of the H matrix.

Where the number of lines is set to M, then H is an M x M channel transmission matrix. Let x be an mx 1 channel input vector, y be an mx 1 channel output vector, and n be an mx 1 noise vector, respectively. Finally, the channel transmission equation is expressed in the form:

y＝Hx+n

in the downlink signal transmission process, joint transmission processing of signals is performed at a CO end, a precoder is introduced at the CO end, and a coding coefficient of the precoder is denoted as P, so that the transmitted signals are:

the signals received by the receiving end are:

when HP is a diagonal matrix, the crosstalk noise will be eliminated, in which case H^-1Representing the inverse of the channel transmission matrix H.

On the basis of the Vectoring technology, the embodiment of the invention further adjusts the coefficient P of the precoder, inhibits the noise caused by crosstalk, and increases the transmission power on part of lines to achieve the rate increase on one or more lines.

In the following, in subcarrier f₀Increasing the rate of line k is an example to illustrate how the precoder coefficients P are adjusted.

First, at H_kIn search of direct channel h with line k_kkCross talk channel h between the phase differences of_kiForming a set S:

wherein angle (h)_ki,h_kk) Representing a cross-talk channel h_kiAnd h_kkA phase difference.

Arranging the S elements from large to small according to the amplitude value to obtain a set

The amplitude represented therein.

Suppose at subcarrier f₀In the above, the transmission power of the N lines needs to be adjusted to speed up the line k, where N is greater than or equal to 1 and less than or equal to M; the target channel of line k is direct channel h_kkAnd channel increment Δ h_kkThe sum, i.e., the increment in the target channel relative to the direct channel, is: then the target channel for line k may also be represented as

Assuming we only need to speed up line k, the target channels on the remaining M-1 lines other than line k should be equal to the direct channel, i.e. the channel increment is 0, noted as i ≠ k. The final target channel matrix to be formed is recorded as:

wherein, the diagonal matrix takes a direct channel as a main diagonal element; i.e. Δ h except the kth main diagonal element_kkBesides, the other elements are all 0 matrixes.

The coefficient P of the precoder is

Further, if there is a need to speed up other lines, such as line i, then that is required

According to the embodiment of the invention, on any time slice and frequency spectrum segment, the signals to be transmitted on the lines are precoded by utilizing the specific precoding coefficient, so that each line can increase a part of transmission power while transmitting the signals on the line per se at a certain power, and the speed of a certain line or a plurality of lines is increased while the noise caused by crosstalk is inhibited.

Correspondingly, an embodiment of the present invention provides a method for increasing a line rate, as shown in fig. 2, where the method includes:

step 201, at the transmitting end, obtaining a precoding coefficient P, where H is^-1The inverse matrix for representing the channel transmission matrix H on the M twisted pairs is a diagonal matrix which takes a direct channel in the channel transmission matrix H as a main diagonal element; Δ H_kIs divided by the kth main diagonal element by Δ h_kkBesides, the other elements are all matrixes of 0, wherein N represents the number of lines needing to adjust the transmission power, and N is more than or equal to 1 and less than or equal to M; and is a direct channel h with the line k_kkCross talk channel h between the phase differences of_kiArranging elements of a set formed after the elements are arranged from large to small according to amplitude values;

step 203, utilizing the precoding coefficient P to precode signals to be transmitted on the M twisted-pair cables;

and step 205, sending out the pre-coded signal to be sent.

This may achieve an increase in the line rate of line k.

Further, the channel transmission matrix H on the M twisted pairs is represented as where the diagonal element H_iiDirect channel, off diagonal element h representing line i_ijRepresenting a crosstalk channel of a line j to a line i, wherein i is more than or equal to 1 and less than or equal to M, j is more than or equal to 1 and less than or equal to M, and i is not equal to j; can be represented as wherein h_MMA direct channel representing line M; Δ H_kCan be expressed as

Further, the Δ H_kIs obtained by the following method:

Note that, h is a number_kiAnd h_kkBoth are complex numbers, so that there is a phase difference between them.

Further, after step 205, updated precoding coefficients P' are obtained, where Δ H_gIs divided by the g-th main diagonal element by Δ h_ggBesides, the remaining elements are all matrices of 0, and the sum is the direct channel h with the line g_ggCross talk channel h between the phase differences of_giAnd arranging the elements of the formed set from large to small according to the amplitude values.

And precoding the signals to be transmitted on the M twisted pairs by utilizing the P'. Of course, the signal to be transmitted is data to be transmitted at the transmitting end after the time point at which the coefficient P' is obtained. And then, sending out the pre-coded signal to be sent.

This can achieve an increase in the line rate for line k and line g.

Similarly, if the line rate of other lines i or more needs to be increased, it can be achieved by only updating the precoding coefficient P to the above mode and precoding the signal to be transmitted by using the updated precoding coefficient P.

According to the embodiment of the invention, the specific precoding coefficient is utilized to precode the signals to be transmitted on the lines, so that part of the transmission power can be increased on the premise that each line transmits the signals on the line at a certain power, and the speed of one line or a plurality of lines can be increased while the noise caused by crosstalk is inhibited. In this embodiment, all the lines in the M lines may be accelerated, or a part of the lines may be optimized to accelerate as required. In addition, although the present embodiment is described with respect to a single subcarrier, the line may be accelerated in the above manner on each of a plurality of subcarriers, respectively.

The embodiment of the present invention further provides a device 30 for increasing a line rate, as shown in fig. 3, including a precoding coefficient obtaining unit 31, a precoder 32 and a transmitter 33;

the precoding coefficient obtaining unit 31 is configured to obtain a precoding coefficient P, where H is^-1The inverse matrix for representing the channel transmission matrix H on the M twisted pairs is a diagonal matrix which takes a direct channel in the channel transmission matrix H as a main diagonal element; Δ H_kIs divided by the kth main diagonal element by Δ h_kkBesides, the other elements are all matrixes of 0, wherein N represents the number of lines needing to adjust the transmission power, and N is more than or equal to 1 and less than or equal to M; and is a direct channel h with the line k_kkCross talk channel h between the phase differences of_kiArranging elements of a set formed after the elements are arranged from large to small according to amplitude values;

the pre-coder 32 pre-codes the signals to be transmitted on the M twisted pairs by using the pre-coding coefficient P;

the transmitter 33 transmits the pre-coded signal to be transmitted.

Further, the channel transmission matrix H on the M twisted pairs is represented as

Further, the Δ H_kThe precoding coefficient acquisition unit 31 is obtained by:

Further, the precoding coefficient obtaining unit 31 obtains the updated precoding coefficient P 'and sends the updated precoding coefficient P' to the precoder 32, where Δ H is the value of Δ H_gIs divided by the g-th main diagonal element by Δ h_ggBesides, the remaining elements are all matrices of 0, and the sum is the direct channel h with the line g_ggCross talk channel h between the phase differences of_giAnd arranging the elements of the formed set from large to small according to the amplitude values.

The precoder 32 precodes signals to be transmitted on the M twisted pairs by using the P'; of course, the signal to be transmitted is data to be transmitted at the transmitting end after the time point when the precoding coefficient obtaining unit 31 obtains the coefficient P'. Then, the transmitter 33 transmits the pre-coded signal to be transmitted

This can achieve an increase in the line rate for line k and line g.

According to the embodiment of the invention, the specific precoding coefficient is utilized to precode the signals to be transmitted on the lines, so that part of the transmission power can be increased on the premise that each line transmits the signals on the line at a certain power, and the speed of one line or a plurality of lines can be increased while the noise caused by crosstalk is inhibited.

It should be further explained that the specific actions performed by the precoding coefficient obtaining unit and the precoder in the network side device are the methods in the above method embodiments.

Another apparatus 40 for increasing line rate is further provided in the embodiments of the present invention, as shown in fig. 4, where the apparatus 40 includes: a receiver 41, a processor 42 and a transmitter 43.

and a transmitter 43, configured to send out the pre-coded signal to be sent.

In the above embodiments, it should be understood that the Processor may be a Central Processing Unit (CPU), other general purpose processors, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks. In particular, the network processing described above may be implemented on a general-purpose component such as a computer or network component having sufficient processing power, memory resources, and network throughput capability.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

A method for increasing the line rate, characterized in that, comprising:

At the sending end, the precoding coefficient P is obtained, the Where H ^-1 represents the inverse matrix of the channel transmission matrix H on M twisted pairs, is a diagonal matrix with the main diagonal elements of the direct channel in the channel transmission matrix H; ΔH _k is a matrix whose elements are all 0 except the kth main diagonal element is Δh _kk , Where N represents the number of lines that need to adjust the transmission power, and 1≤N≤M; and is the phase difference with the direct channel h _kk of line k at The elements of the set formed after the crosstalk channel h _ki is arranged from large to small according to the amplitude value;

Precoding the signals to be sent on the M twisted pairs by using the precoding coefficient P;

Send the precoded signal to be sent.

The method according to claim 1, wherein the channel transmission matrix H on the M twisted pairs is expressed as Among them, the diagonal element h _ii represents the direct channel of line i, and the off-diagonal element h _ij represents the crosstalk channel of line j to line i, 1≤i≤M, 1≤j≤M, and i≠j; can be expressed as where h _MM represents the direct channel of line M; ΔH _k can be expressed as

The method according to claim 1 or 2, wherein the ΔH _k is obtained by the following method:

In the set of the direct channel of line k and the crosstalk channels of other lines in the M lines to line k, that is, H _k , the phase difference with the direct channel h _kk of the line k is searched out in The crosstalk channel h _ki between constitutes a set S, where angle(h _ki ,h _kk ) represents the phase difference between the crosstalk channel h _ki and h _kk ; arrange the elements of S according to the amplitude value from large to small to obtain the set in express The magnitude of ; then ΔH _k is obtained by the above.

The method according to any one of claims 1 to 3, wherein the method further comprises,

Obtain the updated precoding coefficient P', the Among them, ΔH _g is a matrix whose elements are all 0 except the gth main diagonal element is Δh _gg , and the and is the phase difference with the direct channel h _gg of line g at The crosstalk channel h _gi between the elements of the set formed after the amplitude values are arranged from large to small.

Precoding the signals to be sent on the M twisted pairs by using the P′; and sending the precoded signals to be sent.

A device for increasing the line rate, characterized in that it includes: a precoding coefficient acquisition unit 31, a precoder 32 and a transmitter 33;

The precoding coefficient acquisition unit 31 is configured to obtain a precoding coefficient P, the Where H ^-1 represents the inverse matrix of the channel transmission matrix H on M twisted pairs, is a diagonal matrix with the main diagonal elements of the direct channel in the channel transmission matrix H; ΔH _k is a matrix whose elements are all 0 except the kth main diagonal element is Δh _kk , Where N represents the number of lines that need to adjust the transmission power, and 1≤N≤M; and is the phase difference with the direct channel h _kk of line k at The elements of the set formed after the crosstalk channel h _ki is arranged from large to small according to the amplitude value;

The precoder 32 is configured to use the precoding coefficient P to precode the signals to be transmitted on the M twisted pairs;

The transmitter 33 is used for sending out the precoded signal to be sent.

The device according to claim 5, wherein the channel transmission matrix H on the M twisted pairs is expressed as

Among them, the diagonal element h _ii represents the direct channel of line i, and the off-diagonal element h _ij represents the crosstalk channel of line j to line i, 1≤i≤M, 1≤j≤M, and i≠j; can be expressed as where h _MM represents the direct channel of line M; ΔH _k can be expressed as

The device according to claim 5 or 6, wherein the precoding coefficient obtaining unit 31 is also used to obtain ΔH _k , specifically comprising:

In the set of the direct channel of line k and the crosstalk channels of other lines in the M lines to line k, that is, H _k , the phase difference with the direct channel h _kk of the line k is searched out in The crosstalk channel h _ki between constitutes a set S, where angle(h _ki ,h _kk ) represents the phase difference between the crosstalk channel h _ki and h _kk ; arrange the elements of S according to the amplitude value from large to small to obtain the set in express The magnitude of ; then get ΔH _k by the above.

The device according to any one of claims 5 to 7, characterized in that, after the precoding coefficient acquisition unit 31 obtains the updated precoding coefficient P', it sends it to the precoder, and the Among them, ΔH _g is a matrix whose elements are all 0 except the gth main diagonal element is Δh _gg , and the and is the phase difference with the direct channel h _gg of line g at The crosstalk channel h _gi between the elements of the set formed after the amplitude values are arranged from large to small.

The precoder uses the P' to precode the signals to be sent on the M twisted pairs.

A device for increasing a line rate is characterized by comprising: a receiver 41 , a processor 42 and a transmitter 43 .

The receiver 41 is used to obtain the channel transmission matrix H on M twisted pairs; specifically, H is expressed as

Processor 42, used to calculate the precoding coefficient P, the Where H ^-1 represents the inverse matrix of the channel transmission matrix H on M twisted pairs, is a diagonal matrix with the main diagonal elements of the direct channel in the channel transmission matrix H; ΔH _k is a matrix whose elements are all 0 except the kth main diagonal element is Δh _kk , Where N represents the number of lines that need to adjust the transmission power, and 1≤N≤M; and is the phase difference with the direct channel h _kk of line k at The elements of the set formed after the crosstalk channel h _ki is arranged from large to small according to the amplitude value; use the precoding coefficient P to precode the signals to be sent on the M twisted pairs;

The transmitter 43 is configured to transmit the precoded signal to be transmitted.

The device according to claim 9, wherein the channel transmission matrix H on the M twisted pairs is expressed as