CN102932041B - Method for encoding and decoding asynchronous space-time code for collaborative multi-point transmission - Google Patents

Abstract

The invention discloses a method for encoding and decoding an asynchronous space-time code for collaborative multi-point transmission, to solve the problem that the collaborative communication can not be carried out due to time asynchronization and frequency offset during collaborative multi-point joint processing. The method comprises the following specific steps that: (1) user equipment estimates the channel parameter and feeds back the channel parameter to remote wireless equipment; (2) different remote wireless equipment constructs delay convolutional encoding matrixes; (3) the user equipment estimates the overall equivalent channel matrix of the remote wireless equipment; (4) the user equipment constructs the frequency offset matrix; (5) an eNodeB evolutional base station transmits the symbol sequence; (6) the remote wireless equipment carries out space-time coding on the information sequence and sends the information sequence; (7) the user equipment carries out frequency compensation on the received symbol sequence; and (8) the user equipment judges the feedback decoding by using the minimum mean square error and decodes. Due to the adoption of the method, the full-mark set gain can be obtained without carrying out accurate time and frequency synchronization, and the decoding complexity is reduced.

Description

Asynchronous space-time code coding and decoding method in coordinated multi-point transmission

Technical Field

The invention belongs to the technical field of communication, relates to an asynchronous space-time code technology, in particular to an asynchronous space-time code coding and decoding method for a coordinated multi-point transmission system, and can be used for a distributed coordinated multi-point transmission system of future wireless communication.

Background

In a multi-cell cellular system, the frequency spectrum efficiency of a communication system can be improved by adopting the MIMO technology, however, due to the existence of co-channel interference, the throughput of an edge cell cannot be effectively improved, and in order to solve the problem, a coordinated multi-point CoMP transmission technology is provided on the basis of the MIMO technology. The remote wireless devices of multiple cells in CoMP cooperate with each other, and can communicate with the users of the edge cell at the same time, which not only improves the reliability of the system, but also further improves the throughput of the edge cell and the throughput of the overall system. The CoMP transmission technology includes a coordinated scheduling CS mode and a joint processing JP mode, where the CoMP-JP mode may be implemented by multiple remote wireless devices simultaneously transmitting data to a user equipment, for example, the remote wireless device 1 and the remote wireless device 2 simultaneously transmit data to the user equipment 1 located at a boundary between two cells, all the remote wireless devices in CoMP-JP are controlled by the same evolved node b, and all the remote wireless devices perform joint processing on information to eliminate inter-user interference, and then simultaneously transmit the information to the user equipment to convert an interference signal into a useful signal for utilization, so as to effectively utilize inter-cell interference. The gain of CoMP-JP comes from two aspects: firstly, signals sent by cells participating in cooperation are all useful signals, and the total interference level suffered by a terminal is reduced; and secondly, the signals of the cells participating in the cooperation are mutually superposed, so that the power level of the signals received by the terminal is improved, in addition, the common distance between the antennas of different cells is larger and is far larger than half wavelength, the combined processing also can possibly obtain diversity gain, and the service quality and the throughput of cell edge users are improved.

The CoMP-JP mode of coordinated multipoint joint processing can be applied to a single or multiple user equipments UE under the condition of given time domain and frequency domain resources, and under the scenario of multiple remote wireless equipments and multiple user equipments, the time and frequency synchronization between different remote wireless equipments and user equipments cannot be simultaneously solved by using a conventional method. The existing space-time processing and coding and decoding technology cannot be applied to a scene with non-precise synchronization of time and frequency, so that the space-time processing and coding and decoding technology with certain tolerance to the non-precise synchronization of the time and the frequency needs to be researched for a coordinated multi-point joint processing CoMP-JP mode.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an asynchronous space-time coding and decoding method in coordinated multi-point transmission, which can effectively obtain full diversity gain, improve the service quality and the throughput of cell edge users and improve the reliability of a coordinated communication system.

In order to achieve the above object, the asynchronous space-time coding and decoding method in coordinated multi-point transmission of the present invention comprises the following steps:

(1) initializing a system: different remote wireless devices adopt a minimum mean square error channel estimation method to respectively estimate channel parameter information, time delay information and frequency offset information between the user equipment and a plurality of different remote wireless devices; the user equipment feeds the obtained information back to the corresponding remote wireless equipment;

(2) constructing a time delay convolutional coding matrix:

2a) the far-end wireless device calculates a translational full rank polynomial sequence using an iterative method: { P₁(x),P₂(x),…P_R(x) In which P is_r(x) Is a translational full rank polynomial at the r-th remote wireless device,r is the number of remote wireless devices, and R is more than 1, R is 1, … … R;

2b) for the above { P₁(x),P₂(x),…P_R(x) Normalizing the translation full rank polynomial sequence to obtain a normalized translation full rank polynomial sequence:

<math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>,</mo> <msub> <mi>P</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>}</mo> <mo>,</mo> <mo></mo> </mrow> </math>

wherein,is a normalized translation full rank polynomial at the r-th far-end wireless device;

2c) to the normalized translation full rank polynomial sequenceEach polynomial ofWriting the coefficient corresponding to the x power into a one-dimensional code word matrix according to the sequence from the high power to the low powerWhere the default x-power coefficients are represented by zeros, resulting in a one-dimensional codeword matrix at the r-th remote wireless device:

<math> <mrow> <msup> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mo>[</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mi>U</mi> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mi>U</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>]</mo> <mo>,</mo> </mrow> </math>

wherein U is the length of the one-dimensional code word matrix, and satisfiesIs a polynomialThe x power is the coefficient corresponding to i-1, i is 1, … … U;

2d) according to the one-dimensional code matrix at the r remote wireless deviceObtaining a convolutional coding matrix at an r-th remote wireless device

Wherein the convolution coding matrixA dimensional matrix, wherein N is the number of the symbol sequences sent by the eNodeB evolution type base station;

2e) for convolution coding matrixObtaining the time delay convolution coding matrix of the r-th remote wireless device by using a zero filling method

<math> <mrow> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> </mrow> </msub> </mtd> <mtd> <msup> <mover> <mi>T</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> </mtd> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <mrow> <mo>(</mo> <msub> <mi>&tau;</mi> <mi>max</mi> </msub> <mo>-</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> </mrow> </msub> </mtd> </mtr> </mtable> </mfenced> <mo>,</mo> </mrow> </math>

Wherein the time-delay convolution coding matrixThe dimension matrix is a matrix of dimensions,is NxT_rThe all-zero matrix of the dimension(s),is N × (τ)_max-τ_r) All-zero matrix of dimensions, τ_rFor the time delay, τ, between the r-th remote wireless device and the user equipment_max＝max{τ₁......τ_R}；

(3) User equipment estimates remote wireless equipment integral equivalent channel matrix

(4) The user equipment constructs frequency offset matrices of different remote wireless devices to the user equipment:

wherein the frequency shift matrix e_rIs an M × M dimensional matrix, T_sFor symbol interval, M is time delay convolution coding matrixI.e. M ═ N + U-1+ τ_max)，f_rIs the frequency offset between the r-th remote wireless device and the user equipment, j is an imaginary unit, k is any positive integer, pi is a constant of 3.14, e is a constant of 2.71828183;

(5) an eNodeB evolved node B simultaneously transmits a symbol sequence S ═ S to all remote wireless devices₀,s₁,........,s_N-1]Wherein s is_βRepresents symbols transmitted by different time slots, and satisfies beta-0, …, N-1;

(6) different remote wireless devices all receive a sequence of symbols S ═ S₀,s₁，........,s_N-1]Performing space-time coding, wherein the space-time coding sequence transmitted by each far-end wireless device is as follows:

$Q_r={\left[{\hat{T}}^{\left(r\right)}\right]}^T{S}^T,$

wherein [ ·]^TWhich represents the operation of transposition by means of a transposition operation,a time delay convolution coding matrix for the r far-end wireless equipment;

(7) user equipment receiving space-time coding sequence Q_rAnd using a frequency offset matrix e_rPerforming frequency compensation on the symbol sequence to obtain a symbol sequence y after the frequency compensation of the user equipment, wherein R is 1, … … R;

(8) and the user equipment decodes the symbol sequence y after the frequency compensation by using a minimum mean square error decision feedback decoding method.

Compared with the prior art, the invention has the following advantages:

1. in the coordinated multi-point transmission system, the remote wireless equipment carries out space-time coding on the received symbol sequence by constructing the time delay convolutional coding matrix, so that each remote wireless equipment can work in an asynchronous scene without accurate time synchronization; the user equipment performs frequency compensation on the received symbol sequence by constructing a frequency offset matrix, so that the system is less sensitive to frequency offset.

2. In the coordinated multi-point transmission system, the symbol sequences from different remote wireless devices to the user equipment after space-time coding and frequency compensation can be regarded as time and frequency synchronization, and the user equipment can combine multiple paths of received signals, so that the system obtains full diversity gain.

3. The complexity of the minimum mean square error decision feedback decoding method in the coordinated multi-point transmission system is increased linearly and is lower.

4. The invention can realize independent space-time coding at different remote wireless equipment only by constructing the convolution coding matrixes at different remote wireless equipment in advance, and has low complexity.

Drawings

Fig. 1 is a schematic view of a scenario of cooperative multipoint joint transmission communication applicable to the present invention;

FIG. 2 is a block flow diagram of the present invention;

FIG. 3 is a sub-flow diagram of the present invention for translating a full rank polynomial sequence;

FIG. 4 is a sub-flowchart of the minimum mean square error decision feedback decoding of the present invention;

FIG. 5 is a simulation plot of bit error rate versus signal-to-noise ratio for two remote wireless device scenarios in accordance with the present invention;

FIG. 6 is a simulation plot of bit error rate versus signal-to-noise ratio for a scenario of three remote wireless devices in accordance with the present invention;

fig. 7 is a simulation graph of error rate versus variance in frequency offset for a scenario of three remote wireless devices in accordance with the present invention.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1, a coordinated multi-point joint transmission communication scenario includes an eNodeB evolved node b, R remote radio devices, and 1 user equipment, and R > 1 is satisfied. The eNodeB evolution type base station is provided with an antenna, the remote wireless equipment is provided with an antenna, and the user equipment is provided with an antenna. The eNodeB evolution type base station and the remote wireless equipment are connected by optical fibers, different remote wireless equipment and the eNodeB evolution type base station are considered to be synchronous in time and frequency, and a flat fading wireless channel is arranged between the remote wireless equipment and the user equipment. An eNodeB evolution base station sends the same information symbol sequence to each remote wireless device through optical fibers; the remote wireless equipment carries out space-time coding on the received information symbol sequence and then sends the information symbol sequence to the user equipment through respective flat fading wireless channels; the user equipment receives information sequences from different remote wireless devices, decodes the information sequences by using minimum mean square error decision feedback decoding, and demodulates and recovers the information sent by the eNodeB evolved node B.

The process of the invention for completing asynchronous space-time coding and decoding of a coordinated multi-point transmission system is shown in fig. 2, and the implementation steps are as follows:

step 1, system initialization:

1a) remote wireless devices in different cells send signal sequences, user equipment adopts a minimum mean square error channel estimation method in the paper Mehrzad Bigusesh and the like, "Training-based MIMO channel estimation of a study of estimation channels and optimization signals" IEEE channels. Signal Processing, vol.54, No.3 and Mar.2006. channel parameter information from the remote wireless devices in different cells to the user equipment, h_rChannel parameter information between an R-th remote wireless device and user equipment, wherein the value of R is R1, 2.

1b) The remote wireless equipments in different cells transmit signal sequences, the user equipment adopts the minimum mean square error channel estimation method in the paper Mehrzad Biguesh, etc. 'tracking-based MIMO channel estimation, a study of estimation channels and estimation signals' IEEE tracks, Signal Processing, vol.54, No.3, Mar.2006, estimates the frequency offset, f, of the remote wireless equipments in different cells to the user equipment_rIs the frequency offset between the r-th remote wireless device and the user equipment;

1c) remote wireless devices in different cells send signal sequences, user equipment adopts a minimum mean square error channel estimation method in the paper Mehrzad Bigusesh and the like, "Training-based MIMO channel estimation of a study of estimation channels and optimization signals" IEEE transmissions. Signal Processing, vol.54, No.3 and Mar.2006. time delay, tau, from the remote wireless devices in different cells to the user equipment is estimated_rIs the time delay between the r-th remote wireless device and the user equipment;

1d) and the user equipment feeds back the obtained channel parameter information, frequency offset information and time delay information from the remote wireless equipment of different cells to the user equipment to the corresponding remote wireless equipment.

Step 2, constructing a time delay convolution coding matrix at the far-end wireless equipment:

2a) the remote wireless device calculates a translational full rank polynomial sequence { P } using an iterative method₁(x),P₂(x),…P_R(x) In which P is_r(x) Is a translational full rank polynomial at the R-th remote wireless device, R being the number of remote wireless devices, satisfying R > 1, R1, … … R;

referring to fig. 3, the specific implementation of this step is as follows:

2a1) the iteration number n is initialized to 1, and the translation full rank polynomial sequence is initialized to { P }₁(x)＝1}；

2a2) The iteration number n is increased by 1, and the translation full rank polynomial sequence { P when the iteration number n-1 is judged₁(x),P₂(x),…P_n-1(x) In P₁(x),P₂(x),…P_n-1(x) If the greatest common divisor GCD is 1, go to step 2a 3); if the greatest common divisor GCD is u (x), where u (x) is not equal to 1, go to step 2a 4);

2a3) two polynomials q are chosen₂(x) Andsatisfy q₂(x) Can not be removed completelyWherein the polynomial q₂(x) Is an arbitrary polynomial with the highest power degree of 1Is an arbitrary polynomial of the highest power degree n-1, according to { P }₁(x),P₂(x),…P_n-1(x)}、q₂(x) Andto obtain an overlapTranslation full rank polynomial sequence at generation number n <math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mrow> <mi>n</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mo>}</mo> <mo>=</mo> <mo>{</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mover> <mi>q</mi> <mo>^</mo> </mover> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>}</mo> <mo>;</mo> </mrow> </math>

2a4) Two polynomials q are chosen₂(x) Andsatisfy q₂(x) Can not be removed completelyWherein the polynomial q₂(x) Is an arbitrary polynomial with the highest power degree of 1Is an arbitrary polynomial of the highest power degree n-1, according to { P }₁(x),P₁(x),…P_n-1(x)}、q₂(x) Andobtaining a translation full rank polynomial sequence when the iteration number n is obtained <math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mrow> <mi>n</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mo>}</mo> <mo>=</mo> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mover> <mi>q</mi> <mo>^</mo> </mover> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>}</mo> <mo>;</mo> </mrow> </math>

2a5) Judging whether the iteration number n is equal to R or not, and if the iteration number n is equal to R, obtaining a translation full rank polynomial sequence { P) corresponding to all the remote wireless equipment₁(x),P₂(x),…P_R(x) }; if the iteration number n is less than R, executing the step 2a 2);

2b) all the translation full rank polynomial sequences { P) corresponding to the remote wireless equipment obtained in the step₁(x),P₂(x),…P_r(x) Obtaining a normalized translation full rank polynomial sequence according to the following formula:

<math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>,</mo> <msub> <mi>P</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>}</mo> </mrow> </math>

wherein,a normalized translation full rank polynomial at the r-th far-end wireless device;

2c) for each polynomial in the normalized translated full rank polynomial sequence obtained aboveWriting the coefficients corresponding to the x power into a one-dimensional code word matrix form according to the sequence from the high power to the low power, wherein the default x power coefficients are represented by zero, and obtaining a one-dimensional code word matrix at the r-th remote wireless device:

<math> <mrow> <msup> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mo>[</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mi>U</mi> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mi>U</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>]</mo> </mrow> </math>

wherein, U is the length of the one-dimensional code matrix, and satisfies that U is R-1,is a polynomialThe middle x power is the coefficient corresponding to i-1, and for the default x power,equal to zero, where i ═ 1, … … U, e.g. polynomial x⁶+x⁴+x³The one-dimensional codeword matrix corresponding to + x +1 is [1,0,1,1 ]]；

2d) The obtained one-dimensional code word matrixes at different remote wireless devicesObtaining convolutional coding matrixes at different remote wireless devices according to the following construction mode, wherein the convolutional coding matrix at the r-th remote wireless device is as follows:

wherein,a dimension matrix, wherein N is the number of the symbol sequences sent by the eNodeB evolution type base station, and U is the length of the one-dimensional code matrix;

2e) the convolution coding matrix of the above-mentioned r far-end wireless equipment is coded according to the characteristic that there is time delay from different far-end wireless equipment to user equipmentMethod for protecting a sequence of symbols using zero padding by adding a guard interval equal to the maximum time delay τ between different remote wireless devices and a user equipment_max＝max{τ₁...…τ_RTime delay convolution coding of the r-th remote wireless deviceThe matrix expression is as follows:

<math> <mrow> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> </mrow> </msub> </mtd> <mtd> <msup> <mover> <mi>T</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> </mtd> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <mrow> <mo>(</mo> <msub> <mi>&tau;</mi> <mi>max</mi> </msub> <mo>-</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> </mrow> </msub> </mtd> </mtr> </mtable> </mfenced> <mo>,</mo> </mrow> </math>

wherein the time-delay convolution coding matrixThe dimension matrix is a matrix of dimensions,is NxT_rThe all-zero matrix of the dimension(s),is N × (τ)_max-τ_r) All-zero matrix of dimensions, τ_rIs the time delay between the r-th remote wireless device and the user equipment.

Step 3, the user equipment estimates the integral equivalent channel matrix of the remote wireless equipment:

3a) before sending the symbol sequence, the eNodeB evolved node b sends a training sequence a ═ a known to the user equipment to all remote radio devices₀,A₁,........,A_N-1]Wherein A is_αDenotes symbols transmitted by different time slots, α ═ 0, …, N-1;

3b) different remote wireless devices utilize the obtained time delay convolution coding matrixAll carry on the space-time coding to the training sequence A received, the r far-end wireless device carries on the space-time coding training sequence W after the space-time coding to the training sequence_r：

$W_r={\left[{\hat{T}}^{\left(r\right)}\right]}^t{A}^T$

Wherein, the space-time coding training sequence W_rDimension of (D) is Mx 1 dimension [ ·]^TRepresenting a transpose operation;

3c) different remote wireless devices transmit respective space-time coding training sequences W_rSending to the user equipment, the user equipment receiving the training symbol sequenceThe expression of (a) is as follows:

<math> <mrow> <mover> <mi>y</mi> <mo>~</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <msup> <msub> <mi>W</mi> <mn>1</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <msup> <msub> <mi>W</mi> <mn>2</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <msup> <msub> <mi>W</mi> <mi>R</mi> </msub> <mi>T</mi> </msup> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>+</mo> <mi>I</mi> </mrow> </math>

<math> <mrow> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <msup> <mi>A</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>I</mi> </mrow> </math>

whereinThe user equipment receives the training symbol sequenceDimension of (d) is MR x 1 dimension, h_rFor channel parameter information between the r-th remote wireless device and the user equipment, I is a noise matrix of dimension MR × 1, where each dimension obeys a mean of 0 and a variance of 0Complex gaussian distribution of (M) time-delay convolutional coding matrixI.e. M ═ N + U-1+ τ_max)，[·]^TRepresenting a transpose operation;

3d) the user equipment receives the training symbol sequence by using the known training sequence A and the minimum mean square error channel estimation methodPerforming channel estimation to estimate the overall equivalent channel matrix of the remote wireless device <math> <mrow> <mover> <mi>H</mi> <mo>^</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>.</mo> </mrow> </math>

Step 4, the user equipment utilizes the frequency offset f from different remote wireless equipment to the user equipment estimated in the step 1b)_rConstructing frequency offset matrixes of different remote wireless devices to the user equipment, wherein the frequency offset matrix e of the r-th remote wireless device at the user equipment_r：

Wherein the frequency shift matrix e_rIs an M × M dimensional matrix, T_sFor information symbol interval, M is time delay convolution coding matrixI.e. M ═ N + U-1+τ_max) J is an imaginary unit, k is any positive integer, pi is a constant of 3.14, and e is a constant of 2.71828183.

Step 5, the eNodeB evolution base station simultaneously sends a symbol sequence S ═ S to all remote wireless devices₀,s₁,........,s_N-1]Wherein s is_βAnd indicating symbols transmitted by different time slots, wherein beta is 0, …, and N-1, and N is the number of symbol sequences transmitted by the eNodeB evolved node b.

And 6, different remote wireless devices utilize the time delay convolution coding matrix of the r-th remote wireless device obtained in the stepFor the received symbol sequence S ═ S₀,s₁,........,s_N-1]Respectively carrying out space-time coding, wherein the space-time coding sequence of the r far-end wireless equipment after the space-time coding is as follows:

$Q_T={\left[{\hat{T}}^{\left(r\right)}\right]}^T{S}^T$

wherein Q is_rIs a space-time coding sequence at the r far-end wireless equipment, the dimension is M multiplied by 1 dimension, M is a time delay convolution coding matrixI.e. M ═ N + U-1+ τ_max)，[·]^TRepresenting a transpose operation.

And 7, receiving the symbol sequence by the user equipment and performing frequency compensation:

7a) different remote wireless devices transmit space-time coded information sequence Q_rSending to the user equipment, where the expression of the received symbol sequence at the user equipment is as follows:

<math> <mrow> <mover> <mi>y</mi> <mo>^</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <msup> <msub> <mi>Q</mi> <mn>1</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <msup> <msub> <mi>Q</mi> <mn>2</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <msup> <msub> <mi>Q</mi> <mi>R</mi> </msub> <mi>T</mi> </msup> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> </mrow> </math>

<math> <mrow> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> <mo>=</mo> <mover> <mi>H</mi> <mo>^</mo> </mover> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> </mrow> </math>

wherein h is_rFor channel parameter information between the r-th remote wireless device and the user equipment, Q_rIs a space-time code sequence at the r-th remote wireless device, <math> <mrow> <mover> <mi>H</mi> <mo>^</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> </mrow> </math> n is a noise matrix of MR x 1 dimension, wherein each dimension obeys a mean value of 0 and a variance of 0Complex gaussian distribution of [ ·]^TRepresenting transpose operations, M being a time delay convolutional coding matrix of different remote wireless devicesI.e. M ═ N + U-1+ τ_max)；

7b) The user equipment utilizes the frequency offset matrix e of the r far-end wireless equipment to the information sequence received from the r far-end wireless equipment_rAnd performing frequency compensation, wherein the expression of the symbol sequence y after the frequency compensation of the user equipment is as follows:

<math> <mrow> <mi>y</mi> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>e</mi> <mn>1</mn> </msub> </mtd> <mtd> <msub> <mi>e</mi> <mn>2</mn> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>e</mi> <mi>R</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mover> <mi>H</mi> <mo>^</mo> </mover> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>e</mi> <mn>1</mn> </msub> </mtd> <mtd> <msub> <mi>e</mi> <mn>2</mn> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>e</mi> <mi>R</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mi>n</mi> <mo>=</mo> <mi>H</mi> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mover> <mi>n</mi> <mo>^</mo> </mover> </mrow> </math>

wherein the dimension of y is M x 1 dimension, <math> <mrow> <mi>H</mi> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>e</mi> <mn>1</mn> </msub> </mtd> <mtd> <msub> <mi>e</mi> <mn>2</mn> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>e</mi> <mi>R</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mover> <mi>H</mi> <mo>^</mo> </mover> </mrow> </math> for the equivalent channel matrix after frequency compensation,a noise matrix of dimension M x 1, where each dimension obeys a mean of 0 and a variance ofComplex gaussian distribution of (M) time-delay convolutional coding matrixI.e. M ═ N + U-1+ τ_max)。

Step 8, the ue decodes the frequency-compensated symbol sequence y by using the minimum mean square error decision feedback decoding in the paper h.wang, x. — g.xia, and q.yin, "computational efficiency compensation for asynchronous coordinated communications with multiple frequencies," IEEE trans. wireless communications ", vol.8, No.2, pp.648-655, feb.2009:

referring to fig. 4, the specific implementation of this step is as follows:

8a) constructing an auxiliary matrix R according to the equivalent channel matrix H after the frequency compensation and the following formula, wherein the auxiliary matrix R is used for generating a rear-end feedback filter matrix and a front-end feedback filter matrix in the decoding process:

<math> <mrow> <mi>R</mi> <mo>=</mo> <msup> <mi>H</mi> <mi>H</mi> </msup> <mi>H</mi> <mo>+</mo> <mfrac> <msubsup> <mi>&sigma;</mi> <mi>n</mi> <mn>2</mn> </msubsup> <msubsup> <mi>&sigma;</mi> <mi>s</mi> <mn>2</mn> </msubsup> </mfrac> <msub> <mi>I</mi> <mi>N</mi> </msub> </mrow> </math>

wherein, the dimension of R is NxN [. degree]^HDenotes a conjugate transpose operation, H^HThe conjugate transpose of H is represented,for the variance of each element in the noise matrix n,for transmitting a symbol sequence S ═ S₀,s₁,........,s_N-1]Power of (I)_NAn identity matrix of dimension NxN;

8b) performing Cholesky decomposition on the auxiliary matrix R:

R＝L D L^H，

wherein L is a lower triangular matrix whose diagonal element is 1,L^Hthe conjugate transpose of L is represented, and D is a diagonal matrix with dimensions of N multiplied by N;

8c) respectively constructing a rear-end feedback filter matrix B and a front-end feedback filter matrix F by using the lower triangular matrix L and the auxiliary matrix R with the diagonal elements of 1:

F＝LR^-1H^H，

wherein dimension B is NXN dimension, I_NIs an identity matrix of dimension NxN, b_gIs a row vector of dimension 1 XN, g is 0, …, N-1, F is dimension NXN, H^HRepresents the conjugate transpose of H [ ·]^-1Representing an inversion operation, R^-1Represents the inverse of the auxiliary matrix R;

8d) and utilizing the front-end feedback filter matrix F to perform forward filtering on the symbol sequence y after the frequency compensation is performed on the user equipment, and obtaining a vector Z after the forward filtering:

Z＝Fy＝[z₀,z₁……z_N-1]^T

wherein the dimension of Z is Nx1 dimension NxN, Z_γDenotes the vector Z after forward filtering as [ Z ═ Z₀,z₁……z_N-1]^T… where γ is 0,N-1，[·]^TRepresenting a transpose operation;

8e) and according to the rear-end feedback filter matrix B and the vector Z after forward filtering, decoding the information sequence according to the following formula:

<math> <mrow> <msub> <mover> <mi>s</mi> <mo>^</mo> </mover> <mi>j</mi> </msub> <mo>=</mo> <mfenced open='{' close=''> <mtable> <mtr> <mtd> <mi>&theta;</mi> <mrow> <mo>(</mo> <msub> <mi>z</mi> <mn>0</mn> </msub> <mo>)</mo> </mrow> </mtd> <mtd> <mi>j</mi> <mo>=</mo> <mn>0</mn> </mtd> </mtr> <mtr> <mtd> <mi>&theta;</mi> <mrow> <mo>(</mo> <msub> <mi>z</mi> <mi>j</mi> </msub> <mo>-</mo> <msub> <msup> <mi>b</mi> <mo>*</mo> </msup> <mi>j</mi> </msub> <msub> <mover> <mi>S</mi> <mo>^</mo> </mover> <mrow> <mi>j</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mo>)</mo> </mrow> </mtd> <mtd> <mn>1</mn> <mo>&le;</mo> <mi>j</mi> <mo>&le;</mo> <mi>N</mi> <mo>-</mo> <mn>1</mn> </mtd> </mtr> </mtable> </mfenced> </mrow> </math>

wherein, theta (z)₀) Presentation pairSymbol z₀Finding and sign z in constellation diagram₀Constellation point with minimum Euclidean distance Representation pair symbolFinding and marking symbols in constellation diagramsConstellation point with minimum Euclidean distancez_jDenotes the vector Z after forward filtering as [ Z ═ Z₀,z₁……z_N-1]^TThe (c) th element of (a),representing a j x 1-dimensional decoded symbol vector, b^＊ _jB for the j +1 th row in the back-end feedback filter matrix B_jThe first j +1 column of (1), wherein b_jCan be represented as b_j＝[b^* _j,0_1×(N-j)]，b_j0 in (1)_1×(N-j)All zero row vectors of dimension 1 × (N-j), b^* _jIs a row vector of dimension 1 xj.

The effects of the invention can be further illustrated by simulation:

(1) simulation conditions

The modulation mode adopts QPSK, the channels between the remote wireless equipment and the user equipment are independently and equally distributed, and the quasi-static Rayleigh flat fading with the mean value of 0 and the variance of 1 is obeyed. The normalized frequency offsets between the different remote wireless devices and the user equipment in fig. 5 and 6 are independently identically distributed, subject to a mean of 0 and a variance ofNormal distribution of (2); in fig. 7, the normalized frequency offsets between different remote wireless devices and the ue are independently distributed with a signal-to-noise ratio of 25dB, and all are subject to a mean of 0 and a variance of 0Normal distribution of (a), whereinThe value range is (0, 0.25). The delay between different remote wireless devices and the user equipment is 0, tau_max]The oral administration is uniformly distributed, and the maximum delay is tau_maxAnd the length of the zero padding is 4, and the length of the information symbol frame is 20.

(2) Emulated content and results

Simulation 1, under the condition of two remote wireless devices and one user device, respectively adopting 6 modes of decoding forwarding-minimum mean square error decoding, decoding forwarding-minimum mean square error decision feedback decoding, decoding forwarding-maximum likelihood sequence detection, asynchronous space-time code-minimum mean square error decoding of the invention, asynchronous space-time code-minimum mean square error decision feedback decoding of the invention and asynchronous space-time code-maximum likelihood sequence detection of the invention, and simulating the average bit error rate relative to the average signal-to-noise ratio, wherein the result is shown in fig. 5;

simulation 2, under the condition of three remote wireless devices and one user equipment, adopting 6 modes of decoding forwarding-minimum mean square error decoding, decoding forwarding-minimum mean square error decision feedback decoding, decoding forwarding-maximum likelihood sequence detection, asynchronous space-time code-minimum mean square error decoding, asynchronous space-time code-minimum mean square error decision feedback decoding and asynchronous space-time code-maximum likelihood sequence detection, and simulating the average bit error rate relative to the average signal-to-noise ratio, wherein the results are shown in fig. 6.

The simulation results of fig. 5 and 6 show that: when the signal to noise ratio is high, the error rate curve of the asynchronous space-time code-minimum mean square error decision feedback decoding is obviously lower than the error rate curve of the decoding forwarding-minimum mean square error decision feedback decoding, and the error rate of the asynchronous space-time code-minimum mean square error decision feedback decoding method is lower; under the condition of asynchronous space-time codes or decoding and forwarding, the curve slopes of minimum mean square error decision feedback decoding and maximum likelihood sequence detection are approximately the same as the signal-to-noise ratio is increased, and the minimum mean square error decision feedback decoding can obtain the same diversity gain as the maximum likelihood sequence detection.

Simulation 3, under the condition of three remote wireless devices and one user device, respectively adopting 6 modes of decoding forwarding-minimum mean square error decoding, decoding forwarding-minimum mean square error decision feedback decoding, decoding forwarding-maximum likelihood sequence detection, asynchronous space-time code-minimum mean square error decoding, asynchronous space-time code-minimum mean square error decision feedback decoding and asynchronous space-time code-maximum likelihood sequence detection, and simulating the average error rate relative to the frequency deviation variance, wherein the result is shown in fig. 7.

From fig. 7 it can be seen that: the error rate curve of the asynchronous space-time code-minimum mean square error decision feedback decoding is obviously lower than that of decoding forwarding-minimum mean square error decision feedback decoding, and under the condition that the normalized frequency deviation variance is the same, the error rate of the asynchronous space-time code-minimum mean square error decision feedback decoding method is lower, so that the reliability of a system can be improved, and the interrupt probability performance of the system can be improved.

Claims (5)

1. An asynchronous space-time coding and decoding method in coordinated multi-point transmission comprises the following steps:

(1) initializing a system: the user equipment respectively estimates channel parameter information, time delay information and frequency offset information between the user equipment and a plurality of different remote wireless devices by adopting a minimum mean square error channel estimation method; the user equipment feeds the obtained information back to the corresponding remote wireless equipment;

(2) constructing a time delay convolutional coding matrix:

2a) remote wireless device utilizing iterative methodCalculating a translation full rank polynomial sequence: { P₁(x),P₂(x),P_r(x)…P_R(x) In which P_r(x) Is a translational full rank polynomial at the R-th remote wireless device, R being the number of remote wireless devices, satisfying R > 1, R1, … … R;

2b) for the above { P₁(x),P₂(x),…P_R(x) Normalizing the translation full rank polynomial sequence to obtain a normalized translation full rank polynomial sequence:

<math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mi>r</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>,</mo> <msub> <mi>P</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>}</mo> <mo>,</mo> </mrow> </math>

wherein,is a normalized translation full rank polynomial at the r-th far-end wireless device;

2c) to normalized translation full rank polynomial sequence <math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>,</mo> <msub> <mi>P</mi> <mi>r</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>,</mo> <msub> <mi>P</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>/</mo> <msqrt> <mi>R</mi> </msqrt> <mo>}</mo> </mrow> </math> Each polynomial ofWriting the coefficients corresponding to the x power into a one-dimensional code word matrix form according to the sequence from the high power to the low power, wherein the default x power coefficients are represented by zero to obtain a one-dimensional code word matrix at the position of the r-th remote wireless equipment:

<math> <mrow> <msup> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mo>[</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mi>U</mi> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mrow> <mi>U</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msup> <msub> <mover> <mi>t</mi> <mo>&OverBar;</mo> </mover> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>]</mo> <mo>,</mo> </mrow> </math>

wherein, U is the length of the one-dimensional code matrix, and satisfies that U is R-1,is a polynomialThe x power is the coefficient corresponding to i-1, i is 1, … … U;

2d) according to the one-dimensional code matrix at the r remote wireless deviceObtaining a convolutional coding matrix at an r-th remote wireless device

Wherein the convolution coding matrixThe matrix is an N (N + U-1) dimensional matrix, and N is the number of symbol sequences sent by an eNodeB evolved node B;

2e) for convolution coding momentMatrix ofObtaining the time delay convolution coding matrix of the r-th remote wireless device by using a zero filling method

<math> <mrow> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> </mrow> </msub> </mtd> <mtd> <msup> <mover> <mi>T</mi> <mo>&OverBar;</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> </mtd> <mtd> <msub> <mn>0</mn> <mrow> <mi>N</mi> <mo>&times;</mo> <mrow> <mo>(</mo> <msub> <mi>&tau;</mi> <mi>max</mi> </msub> <mo>-</mo> <msub> <mi>&tau;</mi> <mi>r</mi> </msub> <mo>)</mo> </mrow> </mrow> </msub> </mtd> </mtr> </mtable> </mfenced> <mo>,</mo> </mrow> </math>

Wherein the time-delay convolution coding matrixIs N × (N + U-1+ τ)_max) The dimension matrix is a matrix of dimensions,is NxT_rThe all-zero matrix of the dimension(s),is N × (τ)_max-τ_r) All-zero matrix of dimensions, τ_rFor the time delay, τ, between the r-th remote wireless device and the user equipment_max＝max{τ₁......τ_R}；

(3) User equipment estimates remote wireless equipment integral equivalent channel matrix

(4) The user equipment constructs frequency offset matrices of different remote wireless devices to the user equipment:

wherein the frequency shift matrix e_rIs an M × M dimensional matrix, T_sFor symbol interval, M is time delay convolution coding matrixI.e. M ═ N + U-1+ τ_max)，f_rIs the frequency offset between the r-th remote wireless device and the user equipment, j is an imaginary unit, k is any positive integer, pi is a constant of 3.14, e is a constant of 2.71828183;

(5) an eNodeB evolved node B simultaneously transmits a symbol sequence S ═ S to all remote wireless devices₀,s₁,s_β...,s_N-1]Whereins_βrepresents symbols transmitted by different time slots, and satisfies beta-0, …, N-1; (6) different remote wireless devices all receive a sequence of symbols S ═ S₀,s₁,........,s_N-1]Performing space-time coding, wherein the space-time coding sequence transmitted by each far-end wireless device is as follows:

$Q_r={\left[{\hat{T}}^{\left(r\right)}\right]}^T{S}^T,$

wherein [ ·]^TWhich represents the operation of transposition by means of a transposition operation,a time delay convolution coding matrix for the r far-end wireless equipment;

(7) user equipment receiving space-time coding sequence Q_rAnd using a frequency offset matrix e_rPerforming frequency compensation on the symbol sequence to obtain a symbol sequence y after the frequency compensation of the user equipment, wherein R is 1, … … R;

(8) and the user equipment decodes the symbol sequence y after the frequency compensation by using a minimum mean square error decision feedback decoding method.

2. The cooperative multipoint transmission asynchronous space-time coding and decoding method as recited in claim 1, wherein the far-end wireless device of step 2a) calculates the shifted full rank polynomial sequence by an iterative method: { P₁(x),P₂(x),…P_R(x) The method comprises the following steps:

2.1) initialize the iteration number n to 1, initialize the translation full rank polynomial sequence to { P }₁(x)＝1}；

2.2) increasing the iteration number n by 1, judging the translation full rank polynomial sequence { P ] when the iteration number n-1₁(x),P₂(x),…P_n-1(x) In P₁(x),P₂(x),…P_n-1(x) If the greatest common divisor GCD is 1, execute step 2.2 a); if the greatest common divisor GCD is u (x), where u (x) is not equal to 1, execute step 2.2 b);

2.2a) choosing two polynomials q₂(x) Andsatisfy q₂(x) Can not be removed completelyWherein the polynomial q₂(x) Is an arbitrary polynomial with the highest power degree of 1Is an arbitrary polynomial of the highest power degree n-1, according to { P }₁(x),P₂(x),…P_n-1(x)}、q₂(x) Andobtaining a translation full rank polynomial sequence when the iteration number n is obtained <math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mrow> <mi>n</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mo>}</mo> <mo>=</mo> <mo>{</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>q</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mover> <mi>q</mi> <mo>^</mo> </mover> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>}</mo> <mo>;</mo> </mrow> </math>

2.2b) choosing two polynomials q₂(x) Andsatisfy q₂(x) Can not be removed completelyWherein the polynomial q₂(x) Is an arbitrary polynomial with the highest power degree of 1Is an arbitrary polynomial of the highest power degree n-1, according to { P }₁(x),P₂(x),…P_n-1(x)}、q₂(x) Andobtaining a translation full rank polynomial sequence when the iteration number n is obtained <math> <mrow> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mrow> <mi>n</mi> <mo>-</mo> <mn>1</mn> </mrow> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mo>}</mo> <mo>=</mo> <mo>{</mo> <msub> <mi>P</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <msub> <mi>P</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <msub> <mi>P</mi> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>,</mo> <msub> <mover> <mi>q</mi> <mo>^</mo> </mover> <mi>n</mi> </msub> <mrow> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> <mo>}</mo> <mo>;</mo> </mrow> </math>

2.3) judging whether the iteration number n is equal to R, and if the iteration number n is equal to R, obtaining a translation full rank polynomial sequence { P) corresponding to all the remote wireless devices₁(x),P₂(x),…P_R(x) }; and if the iteration number n is less than R, executing the step 2.2).

3. The cooperative multipoint as claimed in claim 1The encoding and decoding method of asynchronous space-time code in transmission, wherein the user equipment in step (3) estimates the overall equivalent channel matrix of the remote wireless equipmentThe method comprises the following steps:

3a) the eNodeB evolution base station sends a training sequence A ═ A known to the user equipment to all the remote wireless devices₀,A₁,A_α...,A_N-1]Wherein A is_αDenotes symbols transmitted by different time slots, α ═ 0, …, N-1;

3b) different remote wireless devices carry out space-time coding on the received training sequence A to obtain a space-time coding training sequence W_r：

$W_r={\left[{\hat{T}}^{\left(r\right)}\right]}^T{A}^T,$

Wherein, the space-time coding training sequence W_rDimension of (D) is Mx 1 dimension [ ·]^TWhich represents the operation of transposition by means of a transposition operation,a time delay convolutional coding matrix for the R-th remote wireless device, R is 1, … … R;

3c) different remote wireless devices will space-time code training sequence W_rSending the training symbol sequence to the user equipment to obtain the training symbol sequence received by the user equipment

<math> <mfenced open='' close=''> <mtable> <mtr> <mtd> <mover> <mi>y</mi> <mo>~</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <msup> <msub> <mi>W</mi> <mn>1</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <msup> <msub> <mi>W</mi> <mn>2</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <msub> <mi>h</mi> <mi>r</mi> </msub> <msup> <msub> <mi>W</mi> <mi>r</mi> </msub> <mi>T</mi> </msup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <msup> <msub> <mi>W</mi> <mi>R</mi> </msub> <mi>T</mi> </msup> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>+</mo> <mi>I</mi> </mtd> </mtr> <mtr> <mtd> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mi>r</mi> </msub> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>r</mi> <mo>)</mo> </mrow> </msup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <msup> <mi>A</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>I</mi> </mtd> </mtr> </mtable> </mfenced> </math>

Where I is the MR x 1-dimensional noise matrix, h_rChannel parameter information between the r-th remote wireless device and the user equipment;

3d) the user equipment utilizes the known training sequence a ═ a₀,A₁,........,A_N-1]And applying the minimum mean square error channel estimation method to receive the training symbol sequence for the user equipmentPerforming channel estimation to obtain an integral equivalent channel matrix of the remote wireless equipment:

<math> <mrow> <mover> <mi>H</mi> <mo>^</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>.</mo> </mrow> </math>

4. the method for asynchronous space-time coding and decoding in coordinated multipoint transmission according to claim 1, wherein said ue of step (7) receives a space-time coding sequence Q_rAnd using a frequency offset matrix e_rThe frequency compensation is carried out according to the following steps:

4a) different remote wireless devices will space-time coded sequence Q_rSending the symbol sequence to the user equipment to obtain the receiving symbol sequence of the user equipment

<math> <mfenced open='' close=''> <mtable> <mtr> <mtd> <mover> <mi>y</mi> <mo>^</mo> </mover> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <msup> <msub> <mi>Q</mi> <mn>1</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <msup> <msub> <mi>Q</mi> <mn>2</mn> </msub> <mi>T</mi> </msup> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <msup> <msub> <mi>Q</mi> <mi>R</mi> </msub> <mi>T</mi> </msup> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> </mtd> </mtr> <mtr> <mtd> <mo>=</mo> <msup> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>h</mi> <mn>1</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <msub> <mi>h</mi> <mn>2</mn> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>h</mi> <mi>R</mi> </msub> <mrow> <mo>(</mo> <msup> <mover> <mi>T</mi> <mo>^</mo> </mover> <mrow> <mo>(</mo> <mi>R</mi> <mo>)</mo> </mrow> </msup> <mo>)</mo> </mrow> </mtd> </mtr> </mtable> </mfenced> <mi>T</mi> </msup> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> <mo>=</mo> <mover> <mi>H</mi> <mo>^</mo> </mover> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mi>n</mi> </mtd> </mtr> </mtable> </mfenced> </math>

Wherein,for the remote wireless device overall equivalent channel matrix, h_rFor channel parameter information between the r-th remote wireless device and the user equipment, n is a MR x 1-dimensional noise matrix [ ·]^TRepresenting a transpose operation;

4b) user equipment utilizes frequency offset matrix e_rReceiving a sequence of symbols for a user equipmentAnd carrying out frequency compensation to obtain a symbol sequence after the frequency compensation of the user equipment:

<math> <mrow> <mi>y</mi> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>e</mi> <mn>1</mn> </msub> </mtd> <mtd> <msub> <mi>e</mi> <mn>2</mn> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>e</mi> <mi>R</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mover> <mi>H</mi> <mo>^</mo> </mover> <msup> <mi>S</mi> <mi>T</mi> </msup> <mo>+</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>e</mi> <mn>1</mn> </msub> </mtd> <mtd> <msub> <mi>e</mi> <mn>2</mn> </msub> </mtd> <mtd> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> <mo>&CenterDot;</mo> </mtd> <mtd> <msub> <mi>e</mi> <mi>R</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mi>n</mi> <mo>=</mo> <msup> <mi>HS</mi> <mi>T</mi> </msup> <mo>+</mo> <mover> <mi>n</mi> <mo>^</mo> </mover> </mrow> </math>

wherein the dimension of y is M x 1 dimension,for the equivalent channel matrix after frequency compensation,is a noise matrix of dimension M × 1.

5. The method of claim 1, wherein the symbol sequence y after frequency compensation of the ue in step (8) is decoded by using a minimum mean square error decision feedback decoding method, and the method comprises the following steps:

5a) constructing an auxiliary matrix R by using the equivalent channel matrix H after frequency compensation:

<math> <mrow> <mi>R</mi> <mo>=</mo> <msup> <mi>H</mi> <mi>H</mi> </msup> <mi>H</mi> <mo>+</mo> <mfrac> <msubsup> <mi>&sigma;</mi> <mi>n</mi> <mn>2</mn> </msubsup> <msubsup> <mi>&sigma;</mi> <mi>s</mi> <mn>2</mn> </msubsup> </mfrac> <msub> <mi>I</mi> <mi>N</mi> </msub> </mrow> </math>

wherein, the dimension of R is NxN [. degree]^HWhich represents the conjugate transpose operation, is,for the variance of each element in the noise matrix n,for transmitting a symbol sequence S ═ S₀,s₁,........,s_N-1]Power of (I)_NAn identity matrix of dimension NxN;

5b) performing Cholesky decomposition on the auxiliary matrix R:

R＝LDL^H

wherein L is a lower triangular matrix whose diagonal element is 1,conjugate transpose of LD is a diagonal matrix of dimension NxN;

5c) respectively constructing a rear-end feedback filter matrix B and a front-end feedback filter matrix F by using the lower triangular matrix L and the auxiliary matrix R with the diagonal elements of 1:

$B=L-I_N=\left[\begin{array}{c}{b}_0\\ b_1\\ b_g\\ .\\ .\\ .\\ b_{N-1}\end{array}\right]$

F＝LR^-1H^H

wherein, the dimension of B is NxN, I_NIs an identity matrix of dimension NxN, b_gIs a row vector with dimension of 1 XN, g is 0, …, N-1, and F has dimension of NXN, H^HRepresents the conjugate transpose of H [ ·]^-1Representing an inversion operation, R^-1Represents the inverse of the auxiliary matrix R;

5d) and utilizing the front-end feedback filter matrix F to perform forward filtering on the symbol sequence y after the frequency compensation is performed on the user equipment, and obtaining a vector Z after the forward filtering:

Z＝Fy＝[z₀,z₁,z_γ…z_N-1]^T；

wherein the dimension of Z is Nx1 dimension NxN, Z_γRepresents the γ -th element in the forward filtered vector Z, γ ═ 0, …, N-1;

5e) and according to the rear-end feedback filter matrix B and the vector Z after forward filtering, decoding the information sequence according to the following formula:

wherein,indicating the search for and the symbol z in the modulation constellation₀Constellation point with minimum Euclidean distanceIndicating finding and symbols in a modulation constellationConstellation point with minimum Euclidean distancez_jDenotes the vector Z after forward filtering as [ Z ═ Z₀,z₁……z_N-1]^TThe (c) th element of (a),representing a j x 1-dimensional decoded symbol vector, b^* _jFor the j +1 th row B in the back-end feedback filter matrix B_jThe first j +1 column.