CN112821927A - Interference management method and device based on backward internal and external cascade precoding - Google Patents

Interference management method and device based on backward internal and external cascade precoding Download PDF

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CN112821927A
CN112821927A CN201911121028.XA CN201911121028A CN112821927A CN 112821927 A CN112821927 A CN 112821927A CN 201911121028 A CN201911121028 A CN 201911121028A CN 112821927 A CN112821927 A CN 112821927A
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matrix
interference
precoding
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external
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CN112821927B (en
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李钊
朱妍妍
白玉娇
吴芸
刘尊亮
李云志
王路路
商超
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Suzhou Leo Biotechnology Co ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • H04B7/0486—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting taking channel rank into account

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Abstract

The invention discloses an interference management method and device based on backward internal and external cascade precoding; the method comprises the following steps: an interference transmitter selects a code word matrix from a codebook and sets the code word matrix as a matrix design target after the inner and outer pre-coding matrixes are cascaded; by utilizing the interaction between wireless signals, an interference transmitter takes the whole of a plurality of interference components as an equivalent interference, and calculates an equivalent precoding vector aiming at the equivalent interference; then, solving a relational equation of the code word matrix and the internal and external pre-coding matrixes to obtain a combination of various internal and external pre-coding matrixes, and selecting a matched group as the internal pre-coding matrix and the external pre-coding matrix obtained by an interference management method based on backward internal and external cascade pre-coding; and finally, the interference transmitter utilizes the internal precoding matrix and the external precoding matrix to preprocess the transmitted data, so as to realize the management of a plurality of interferences.

Description

Interference management method and device based on backward internal and external cascade precoding
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to an interference management method and device based on backward internal and external cascade precoding.
Background
With the rapid development of the internet of things technology, the internet of things technology is more and more widely applied to the lives of people, and when different internet of things devices coexist in a limited area and share the same communication resource, crosstalk occurs between the internet of things devices, so that the normal work of the devices is affected, and therefore an effective interference management method is needed.
Currently, the current state of the art commonly used in the industry is such that: the existing Interference management methods include Interference Neutralization (IN), Zero-forcing reception (ZF), Interference Steering (IS), Interference Alignment (IA), and Zero-forcing beamforming (ZFBF). The above methods can be divided into two categories: the first type IS interference management implemented at the interfered receiver or transmitter associated with the interfered receiver, e.g., ZF, IN, IS, etc.; the second type is implemented on the interfering transmitter side, e.g., ZFBF and IA. Where IN aims to properly combine signals arriving at the interfered receiver through different paths so that the interfering signal is cancelled while the desired signal remains at the interfered receiver. While IN may cancel interference, generating a neutralizing signal creates power overhead at the transmitter associated with the interfered receiver, which also reduces system performance; IS alters the propagation of interference by generating a pilot signal by a transmitter associated with an interfered receiver, directing the original interference at the interfered receiver in a direction orthogonal to its intended transmission. The IS side focuses on eliminating the significant part of the interference impact on the desired transmission compared to IN, thereby reducing power consumption, but therefore also requires an additional Degree of spatial freedom (DoF) to place the steered interference; ZFBF applications are suboptimal in Multiple Input Multiple Output (MIMO) Broadcast Channels (BC), but as the number of users in the system tends to infinity, the same asymptotic sum capacity as Dirty Paper Coding (DPC) can be achieved, but the requirement for freedom of the method is determined by the total number of desired signals and interference, i.e. one DoF is consumed per interference component; the availability of IA, which adjusts the interference at the interferer so that multiple interfering signals are mapped to a limited subspace at the interfered receiver, is highly dependent on system parameters, such as the number of transmit/receive antennas, etc., even though the interference space at the interfered receiver is minimized, while its desired signal can be transmitted through the interference-free signal subspace, and the conventional interference alignment approach will no longer be applicable when multiple interferences come from the same transmitter, i.e., the IA cannot solve the problem of co-source multi-interference.
In summary, the problems of the prior art are as follows: the existing interference management method still focuses on managing individual interference, neglects the overall effect of the interference, and causes more consumption of resources such as degree of freedom, power and the like. Interference alignment cannot manage multiple interferences from the same interferer. An interference management method based on an interfered receiver and/or a corresponding transmitter thereof requires that an interfered party acquires an interference state through cooperation with an interference source, and consumes resources such as power and freedom, which causes a decrease in communication performance due to interfered communication. Due to the scarcity of the spectrum available for wireless electromagnetic transmission, many existing and emerging medical devices and mobile devices are close to each other and even spectrally overlap, which inevitably leads to strong interference.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides an interference management method and device based on backward internal and external cascade precoding.
The invention is realized in this way, an interference management method based on backward inner and outer cascade precoding, the interference management method based on backward inner and outer cascade precoding includes: the interference transmitter selects a code word matrix from a codebook, the codebook is a set of a group of limited precoding matrixes defined by each transmission rank of a given number of antenna ports, the codebook is arranged at a transmitting and receiving end, and the code word matrix is set as a matrix design target after the inner precoding matrix and the outer precoding matrix are cascaded; by utilizing the interaction between wireless signals, an interference transmitter takes the whole of a plurality of interference components as an equivalent interference, and calculates an equivalent precoding vector aiming at the equivalent interference; then, the interference transmitter solves a relation equation of the code word matrix and the internal and external pre-coding matrixes to obtain a combination of various internal and external pre-coding matrixes, and selects a matched group as the internal pre-coding matrix and the external pre-coding matrix obtained by the interference management method based on backward internal and external cascade pre-coding; and finally, the interference transmitter utilizes the internal precoding matrix and the external precoding matrix to preprocess the transmitted data, so as to realize the management of a plurality of interferences. Further, the interference management method based on backward inner and outer cascade precoding comprises the following steps:
the method comprises the following steps: interfered receiver Rx0Estimate it from the desired transmitter Tx0And an interference transmitter Tx1Channel state information H therebetween0And H10Interfering with the transmitter Tx1Corresponding receiver Rx1Estimate it from the interfering transmitter Tx1Channel state information H therebetween1；Rx0And Rx1Respectively feeding back the estimated channel state information to the associated transmitters Tx0And Tx1，Tx0And Tx1Shared channel state information H0And H10；Tx0To Rx0For data transmission channel matrix H0Represents, Tx1And Rx1H for data transmission channel matrix between1Represents, Tx1And Rx0With the interference channel matrix of H10Represents;
step two: interference transmitter Tx1Selecting a codeword matrix C from a codebookiWhere i denotes the code number of the codeword matrix in the codebook, and the codeword matrix CiAs an interiorPrecoding matrix P1And an outer precoding matrix GeCascaded matrix GeP1The inner precoding matrix P1Is a matrix for precoding data of different paths (multi-path data), the external precoding matrix GeA matrix for precoding equivalent interference formed by different path (multipath) interference so as to achieve interference alignment at an interfered receiver and distinguish data of different paths;
step three: the interference transmitter randomly selects alpha and K according to the interaction relation among K data streams transmitted by the interference transmitter, and converts G into GeEquation G by substituting general solution expression into relational equationeP1＝CiSolving, wherein the outer precoding matrix GeVector of need
Figure BDA0002275475950000041
And H0GePeSatisfy the orthogonal relation
Figure BDA0002275475950000042
GeAs indicated by the general solution thereof,
Figure BDA0002275475950000043
is Tx0Precoding vectors employed, P1Is the internal precoding matrix to be solved, defines
Figure BDA0002275475950000044
PeIs an equivalent precoding vector, and can obtain a vector satisfying a relation equation GeP1＝CiG of (A)eAnd P1Multiple combinations of (2) are designated as { P1,Ge}，GeThe general solution expression of (a) contains three unknown parameters: α, k and PeWherein
Figure BDA0002275475950000045
Is a complex coefficient of the number of the bits,
Figure BDA0002275475950000046
represents one
Figure BDA0002275475950000047
The vector of complex numbers of (a) is,
Figure BDA0002275475950000048
Figure BDA00022754759500000411
represents Tx1The number of antennas equipped;
step four: judging to substitute randomly selected k into GeEquation G obtained by solving the expressioneP1＝CiIf the equation can be solved, executing the step five, otherwise, returning to the step three;
step five: if equation G of the relationshipeP1＝CiIf the order of the augmented matrix is equal to the order of the coefficient matrix, the equations are compatible, and P can be obtained1And GePerforming the step six; else equation GeP1＝CiIncompatibility, finding P1And GePerforming a step seven;
step six: solving to obtain { P1,GeThe exact solution of;
step seven: interfering with the transmitter Tx according to the least-squares principle1From the above calculation, a plurality of { P }1,GeCombine with CiOne group of matches, denoted as { P }1，*，Ge，*I.e. that
Figure BDA00022754759500000410
Wherein n represents the nth { P's obtained by the interference management method based on backward internal and external cascade precoding1,GeThe solution of.
Further, the third step includes:
(1) for modulation symbol set S ═ S1,s2,…,sLIntroduce arbitrary symbols in S
Figure BDA0002275475950000051
As a reference symbol, define
Figure BDA0002275475950000052
(2)GeSatisfy the requirement of
Figure BDA0002275475950000053
Will be conditional
Figure BDA0002275475950000054
Deformation to H10GePe＝αd⊥Wherein d is⊥Representation and Tx0To Rx0A unit vector in which the transmitted signals are orthogonal;
(3) equation pair H10GePe＝αd⊥Left multiplication matrix H with two ends10Contrary to (2)
Figure BDA0002275475950000056
If H is present10Not a square matrix, then
Figure BDA0002275475950000057
Should be formed of H10Pseudo-inverse of
Figure BDA0002275475950000058
Instead of;
(4) defining a vector
Figure BDA0002275475950000059
To obtain GePeα b, wherein
Figure BDA00022754759500000510
Using elementary transformation of the rows of the matrix, from GePeObtained as α b
Figure BDA00022754759500000511
Wherein
Figure BDA00022754759500000512
And
Figure BDA00022754759500000518
respectively representing the coefficient matrix and the solution vector of the equation,
Figure BDA00022754759500000513
is that
Figure BDA00022754759500000514
The unit matrix of (a) is,
Figure BDA00022754759500000515
represents GeThe (c) th column of (a),
Figure BDA00022754759500000516
(5) calculation of GeThe general solution expression of (c) is:
Figure BDA00022754759500000517
another object of the present invention is to provide an interference management apparatus based on backward inner and outer concatenated precoding, which includes an apparatus for performing any one of the above interference management methods based on backward inner and outer concatenated precoding.
In summary, the advantages and positive effects of the invention are: aiming at the problems that the traditional interference management method, such as IA, can not effectively manage a plurality of interferences from the same interference source and the existing forward internal and external cascade precoding method F-IOP is not suitable under some channel conditions, a backward internal and external cascade precoding method B-IOP is provided, which is mutually complemented with the F-IOP method, and the degrees of freedom occupied by a plurality of interferences of an interference communication pair at an interfered receiver are compressed to 1 by self-adapting the two methods, and meanwhile, the interference communication pair has better communication performance (spectrum efficiency).
Drawings
Fig. 1 is a flowchart illustrating an interference management method based on backward inner and outer concatenated precoding according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a system model including two communication pairs according to an embodiment of the present invention;
fig. 3 is a flowchart illustrating an interference management method based on backward inner and outer concatenated precoding according to an embodiment of the present invention;
fig. 4 is a diagram of Rx obtained by an interference management method based on backward inner and outer concatenated precoding in a wireless communication system according to an embodiment of the present invention0And Rx1The spatial spectrum of the signal.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention can align the same source multiple interference to one direction at the interfered receiver, and simultaneously ensures that the receivers corresponding to the signals causing the interference can distinguish the signals in a space domain, namely, the multi-channel data transmission between an interference transmitter and the receivers thereof is carried out.
The following detailed description of the principles of the invention is provided in connection with the accompanying drawings.
In order to solve the difficulties and significance of the above prior art problems: how to preprocess the overall effect of interference, not only aligning the multiple homologous interferences from an interfering transmitter to one direction at an interfered receiver, but also enabling receivers corresponding to the signals causing the interference (namely, receivers corresponding to the interfering transmitter) to distinguish the multiple homologous interferences in a space domain; the significance lies in that: the method eliminates the influence of a plurality of interferences from the same interference source at the interfered receiver, compresses the degree of freedom occupied by the interferences to 1, and ensures that multi-path data transmission between an interference transmitter and a receiver thereof is carried out, thereby improving the system performance.
As shown in fig. 1, an execution main body of the interference management method based on backward internal and external concatenated precoding provided in the embodiment of the present invention is an interference management device based on backward internal and external concatenated precoding, where the device may be independently configured or may be configured in an interference transmitter, and the method includes the following steps:
s101: the interference transmitter selects a code word matrix from the codebook, and the code word matrix is used as a matrix design target after the inner pre-coding matrix and the outer pre-coding matrix are cascaded;
it should be noted that the interfering transmitter in this embodiment is a transmitter that causes interference to another receiver when communicating with its corresponding receiver.
In this embodiment, the codebook is a set of a finite set of precoding matrices defined for each transmission rank of a given number of antenna ports, and the codebook is available to the transceiving end, i.e. the interfering transmitter and the interfering receiver are both provided with the codebook. The codeword matrix in this embodiment may be a result of concatenation of an internal precoding matrix and an external precoding matrix, where the internal precoding matrix is a coding matrix for preprocessing transmitted data, and for example, an interfering transmitter may determine the internal precoding matrix according to a channel matrix between receivers corresponding to the interfering transmitter; the external precoding matrix is designed by utilizing the wireless signal interaction between each transmitter and each receiver, and the interference transmitter equivalently converts the whole of a plurality of interferences into one interference. Further, the interference transmitter uses the result of the obtained cascade of the internal precoding matrix and the external precoding matrix to preprocess the transmitted data.
S102: using the interaction between wireless signals, the interference transmitter takes the whole of a plurality of interference components as an equivalent interference, and calculates an equivalent precoding vector for the equivalent interference;
s103: the interference transmitter solves a relation equation of the code word matrix and the internal and external pre-coding matrixes to obtain a combination of various internal and external pre-coding matrixes, and selects a matched group as the internal pre-coding matrix and the external pre-coding matrix obtained by the interference management method based on backward internal and external cascade pre-coding;
s104: and the interference transmitter utilizes the internal precoding matrix and the external precoding matrix to preprocess the transmitted data so as to realize the management of a plurality of interferences.
The application of the principles of the present invention will now be described in further detail with reference to the accompanying drawings.
As shown in fig. 2, the system model of the present invention is a Z-Interference Channel (ZIC) comprising two communication pairs, the Z-Interference Channel consisting of two interfering transmitters and two interfering receivers, one of which receives an Interference-free signal and the other of which receives Interference-free and Interference-free signals, wherein the receiver Rx receives a signal with Interference and Interference0Subject to interference from transmitter Tx1Of Rx1Is not interfered. TxiAnd Rxi(i-1, 2) are each provided with
Figure BDA0002275475950000082
And
Figure BDA0002275475950000083
root antenna, TxiHas a transmission power of PT. From TxiTo RxiThe data transmission channel matrix is
Figure BDA0002275475950000084
Where i is 1,2, from Tx1To Rx0Is expressed as
Figure BDA0002275475950000085
Using spatially uncorrelated rayleigh flat fading channel models HiAnd H10The elements of (a) are modeled as independent and identically distributed zero-mean unit-variance complex gaussian random variables. It is assumed that all users experience block fading, i.e. the channel parameters remain constant within a block consisting of several consecutive time slots, varying randomly from block to block. RxiCan accurately estimate the channel state information between the desired transmitter and the interference transmitter and feed the channel state information back to the Tx associated with the low-rate and error-free linki. It is assumed that the feedback delay is negligible compared to the time scale of the channel state change. It should be noted that the embodiment scenario shown in fig. 2 is suitable for the embodiment of the present inventionIn one of the scenarios, the applicable scenario of the embodiment of the present invention is not limited thereto.
As shown in fig. 3, the application effect of the interference management method based on backward inner and outer concatenated precoding provided by the embodiment of the present invention is as follows:
step 301: interference transmitter Tx1Channel information is determined.
In particular, the interfered receiver Rx0Estimate it from the desired transmitter Tx0And an interference transmitter Tx1Channel state information H therebetween0And H10Interfering with the transmitter Tx1Corresponding receiver Rx1Estimate it from the interfering transmitter Tx1Channel state information H therebetween1；Rx0And Rx1Respectively feeding back the estimated channel state information to the associated transmitters Tx0And Tx1，Tx0And Tx1By sharing channel state information thereby Tx0And Tx1Channel information H can be obtained separately0And H10；Tx0To Rx0For data transmission channel matrix H0Represents, Tx1And Rx1H for data transmission channel matrix between1Represents, Tx1And Rx0With the interference channel matrix of H10Represents;
step 302: interference transmitter Tx1Selecting a codeword matrix C from a codebookiWhere i denotes the code number of the codeword matrix in the codebook, and the codeword matrix CiMatrix G after concatenation as internal and external precoding matrixeP1The design objective of (1);
in particular, the interference transmitter Tx1Selecting a code word matrix C from the codebook according to a preset rulei. Wherein the inner precoding matrix P1A matrix for precoding data of different paths, the outer precoding matrix GeA matrix for precoding equivalent interference formed by different path interference to align the interference at the interfered receiver and to distinguish the data of different paths.
Step 303: the interference transmitter randomly selects alpha and k, and GeSubstituting the general solution expression into equation GeP1＝CiSolving, wherein the outer precoding matrix GeRelation to be satisfied
Figure BDA0002275475950000091
GeBy its general solution, P1Is the internal precoding matrix to be solved, at this time, GeThe general solution expression of (a) contains three unknown parameters: α, k and Pe；
Specifically, the interference transmitter randomly selects alpha and K according to the interaction relation among K data streams transmitted by the interference transmitter, and sends GeEquation G by substituting general solution expression into relational equationeP1＝CiSolving, wherein the outer precoding matrix GeFor making vectors
Figure BDA0002275475950000101
And H0GePeSatisfy the orthogonal relation
Figure BDA0002275475950000102
GeAs indicated by the general solution thereof,
Figure BDA0002275475950000103
is Tx0Precoding vectors employed, P1Is the internal precoding matrix to be solved, defines
Figure BDA0002275475950000104
PeIs an equivalent precoding vector, and can obtain a vector satisfying a relation equation GeP1＝CiG of (A)eAnd P1Multiple combinations of (2) are designated as { P1,Ge}，GeThe general solution expression of (a) contains three unknown parameters: α, k and PeWherein
Figure BDA0002275475950000105
Is a complex coefficient of the number of the bits,
Figure BDA0002275475950000106
represents one
Figure BDA0002275475950000107
The vector of complex numbers of (a) is,
Figure BDA0002275475950000108
Figure BDA00022754759500001014
represents Tx1The number of antennas provided.
Step 304: judging to substitute randomly selected k into GeEquation of relationship G obtained by solving the expressioneP1＝CiWhether it is solvable.
Specifically, if the equation is solvable, go to step 305, otherwise return to step 303.
For example, to
Figure BDA0002275475950000109
For example, solve equation GeP1＝CiG iseThe general solution expression of (2) is substituted into the relational equation to be transformed to obtain the equation, as shown in formula (1):
Figure BDA00022754759500001010
let Tx1All data streams transmitted adopt Binary Phase Shift Keying (BPSK) modulation mode, and it is set
Figure BDA00022754759500001011
And
Figure BDA00022754759500001012
and is
Figure BDA00022754759500001013
B in formula (1) as reference symbols(1)And b(2)Is sent by the expectationRoad H0And interference channel H10The determined known parameters are used, wherein,
Figure BDA0002275475950000111
k(3)，k(4)is the third and fourth element of k, and
Figure BDA0002275475950000112
and
Figure BDA0002275475950000113
is an unknown number. Because of the fact that
Figure BDA0002275475950000114
Will be provided with
Figure BDA0002275475950000115
And
Figure BDA0002275475950000116
substituting the four unknowns into the formula (1), and simplifying the formula (1) into an equation set comprising four unknowns and four equations;
parameter k(3)And k(4)May cause equation (1) to have no least squares solution. For example when k(3)＝k(4)When the value is equal to 0, the formula (1) is a contradictory homogeneous equation set, and at the moment, the formula (1) has no solution, so that a new parameter k is required to be reset to solve the inner and outer precoding matrices;
step 305: if equation G of the relationshipeP1＝CiIf the order of the augmented matrix is equal to the order of the coefficient matrix, the equations of the relationship are compatible, and P is obtained1And GeTo perform step 306; else equation GeP1＝CiIncompatibility, finding P1And GePerforming step 307;
for example, to
Figure BDA0002275475950000117
Calculate G as an exampleeAnd P1In which C is2Is a codeword selected from a codebook for two-antenna data transmission, j being a variable; definition of
Figure BDA0002275475950000118
Figure BDA0002275475950000119
And
Figure BDA00022754759500001110
rewriting formula (1) to
Figure BDA00022754759500001111
Performing primary row transformation on the augmentation matrix of the equation to obtain
Figure BDA0002275475950000121
Because the rank of the coefficient matrix of the equation is 2 and rank (Ω) ═ 4 > 2, the equation is incompatible, i.e., the equation does not have an exact solution, requiring a solution to the least squares solution;
step 306: solving to obtain { P1,GeThe exact solution of;
step 307: calculating a plurality of { P from said step 304 according to the least squares principle1,GeCombine with CiA matched set;
specifically, the interference transmitter Tx is based on the least square principle1A plurality of { P is calculated from said step 3041,GeCombine with CiOne group of matches, denoted as { P }1，*，Ge，*I.e. that
Figure BDA0002275475950000123
Wherein n represents the nth { P's obtained by the interference management method based on backward internal and external cascade precoding1,GeThe solution of (c);
obtaining a least squares solution of the system of equations may be according to the theorem: a system of non-homogeneous linear equations Ax ═ b, wherein
Figure BDA0002275475950000124
Given that the number of the first and second sets of data,
Figure BDA0002275475950000125
is a solution vector; the requirement that x is the least squares solution of the system of equations Ax ═ b is: x is AHAx＝AHb solution of wherein AHAx＝AHb is a normal set of equations for Ax ═ b. The inner and outer precoding matrices may be represented as:
Figure BDA0002275475950000126
and
Figure BDA0002275475950000127
wherein
Figure BDA0002275475950000128
α，k(3)，k(4)，μ3，μ4Can take any value to produce different GeAnd P1In which μ3，μ4Need to satisfy equation k(3)μ4＝k(4)μ3。
On the basis of the foregoing embodiment, step 303 may specifically include:
(1) for modulation symbol set S ═ S1,s2,…,sLIntroduce arbitrary symbols in S
Figure BDA0002275475950000131
As a reference symbol, define
Figure BDA0002275475950000132
(2)GeSatisfy the requirement of
Figure BDA0002275475950000133
Will be conditional
Figure BDA0002275475950000134
Deformation to H10GePe＝αd⊥Wherein d is⊥Representation and Tx0To Rx0A unit vector in which the transmitted signals are orthogonal;
(3) equation pair H10GePe＝αd⊥Left multiplication matrix H with two ends10Contrary to (2)
Figure BDA0002275475950000138
If H is present10Not a square matrix, then
Figure BDA0002275475950000139
From H10Pseudo-inverse of
Figure BDA00022754759500001310
Instead of;
(4) defining a vector
Figure BDA00022754759500001311
To obtain GePeα b, wherein
Figure BDA00022754759500001312
Using elementary transformation of the rows of the matrix, from GePeObtained as α b
Figure BDA00022754759500001313
Wherein
Figure BDA00022754759500001314
And
Figure BDA00022754759500001320
respectively representing the coefficient matrix and the solution vector of the equation,
Figure BDA00022754759500001315
is that
Figure BDA00022754759500001316
The unit matrix of (a) is,
Figure BDA00022754759500001317
represents GeThe (c) th column of (a),
Figure BDA00022754759500001318
(5) calculation of GeThe general solution expression of (c) is:
Figure BDA00022754759500001319
the application effect of the present invention will be described in detail with reference to the simulation.
1. Simulation conditions are as follows:
simulation object:
the interference management method based on internal and external cascade precoding provided by the invention adopts a Multiple Signal Classification algorithm (MUSIC) to estimate the arrival angle of a Signal, and obtains the spatial spectrum of the Signal observed by a receiving end through MATLAB simulation.
Simulation parameters:
Tx0and Tx1The same transmit power is used. TxiAnd Rxi(i ═ 1,2) are each provided with NTi2 and
Figure BDA0002275475950000144
a root antenna. Tx0To Rx0Transmitting 1-way data
Figure BDA0002275475950000141
Interference transmitter Tx1To Rx1Sending 2-way data
Figure BDA0002275475950000142
And
Figure BDA0002275475950000143
Tx1to Rx0Interference is generated. Wherein Tx1BPSK modulation mode is adopted.
The center frequency of the input signal is f0At 2.4GHZ, the transmit power to noise ratio (SNR) is 20dB and the antenna element spacing is at least half the signal wavelength.
2. Simulation content and analysis thereof:
for the B-IOP method provided by the invention at Tx1When precoding, receiver Rx0And Rx1The spatial spectrum of the observed signal was subjected to MATLAB simulation, the results of which are shown in fig. 4, in which the vertical axis represents the normalized amplitude of the spatial spectrum and the horizontal axis represents the angle of arrival of the signal. As can be seen in FIG. 4(a), at Rx0The equivalent interference formed by the two interferences is aligned to the sub-characteristic pattern, i.e. the equivalent interference is aligned to Rx0Are orthogonal to each other. As can be seen in FIG. 4(b), Rx1The two received desired signals are spatially distinguishable.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (4)

1. An interference management method based on backward internal and external cascade precoding is characterized by comprising the following steps:
an interference transmitter selects a code word matrix from a codebook and sets the code word matrix as a design target of a matrix formed by cascading an internal precoding matrix and an external precoding matrix;
the interference transmitter takes the whole of a plurality of interference components as equivalent interference by utilizing the interaction between wireless signals, and calculates an equivalent precoding vector for the equivalent interference;
the interference transmitter solves a relation equation of the code word matrix and the internal and external pre-coding matrixes to obtain a combination of various internal and external pre-coding matrixes, and selects a matched group as the internal pre-coding matrix and the external pre-coding matrix obtained by an interference management method based on backward internal and external cascade pre-coding;
the interference transmitter pre-processes the transmitted data using the internal precoding matrix and the external precoding matrix to achieve management of multiple interferences.
2. The method for managing interference based on backward internal and external concatenated precoding as claimed in claim 1, wherein said interference transmitter selects a codeword matrix from a codebook, and further comprises, before setting said codeword matrix as a matrix design target after concatenation of an internal precoding matrix and an external precoding matrix:
step 1: interfered receiver Rx0Estimate it from the desired transmitter Tx0And an interference transmitter Tx1Channel state information H therebetween0And H10Interfering with the transmitter Tx1Corresponding receiver Rx1Estimate it from the interfering transmitter Tx1Channel state information H therebetween1，Rx0And Rx1Respectively feeding back the estimated channel state information to the associated transmitters Tx0And Tx1，Tx0And Tx1Shared channel state information H0And H10，Tx0To Rx0For data transmission channel matrix H0Represents, Tx1And Rx1H for data transmission channel matrix between1Represents, Tx1And Rx0With the interference channel matrix of H10Represents;
the interference transmitter selects a code word matrix from a codebook, and sets the code word matrix as a matrix design target after the inner and outer pre-coding matrixes are cascaded, wherein the matrix design target comprises the following steps:
step 2: the interference transmitter Tx1Selecting a codeword matrix C from the codebookiWhere i denotes the index of the codeword matrix in the codebook, and the codeword matrix CiAs an inner precoding matrix P1And an outer precoding matrix GeCascaded matrix GeP1The inner precoding matrix P1A matrix for precoding data of different paths, the outer precoding matrix GeA matrix for precoding equivalent interference formed by different path interference to align interference at an interfered receiver and to distinguish data of different paths;
the interference transmitter solves a relation equation of the code word matrix and the internal and external precoding matrixes to obtain a combination of various internal and external precoding matrixes, and selects a matched group as the internal precoding matrix and the external precoding matrix obtained by the interference management method based on backward internal and external cascade precoding, and the method comprises the following steps:
and step 3: the interference transmitter Tx1According to the interaction relation among K data streams transmitted by the wireless sensor, alpha and K are randomly selected, and G is converted intoeEquation G by substituting general solution expression into relational equationeP1＝CiSolving, wherein the outer precoding matrix GeVector of need
Figure FDA0002275475940000021
And H0GePeSatisfy the orthogonal relation
Figure FDA0002275475940000022
GeAs indicated by the general solution thereof,
Figure FDA0002275475940000023
is Tx0Precoding vectors employed, P1Is the internal precoding matrix to be solved, defines
Figure FDA0002275475940000024
PeIs an equivalent precoding vector to obtain a vector satisfying a relational equation GeP1＝CiG of (A)eAnd P1Multiple combinations of (2) are designated as { P1,Ge}，GeThe general solution expression of (a) contains three unknown parameters: α, k and PeWherein
Figure FDA0002275475940000025
Is a complex coefficient of the number of the bits,
Figure FDA0002275475940000026
represents one
Figure FDA0002275475940000027
The vector of complex numbers of (a) is,
Figure FDA0002275475940000028
Figure FDA0002275475940000029
represents Tx1The number of antennas equipped;
and 4, step 4: judging to substitute randomly selected k into GeEquation G obtained by solving the expressioneP1＝CiIf the equation can be solved, executing the step 5, otherwise, returning to the step 3;
and 5: if equation G of the relationshipeP1＝CiIf the order of the augmented matrix is equal to the order of the coefficient matrix, the equations of the relationship are compatible, and P is obtained1And GePerforming step 6; else equation GeP1＝CiIncompatibility, finding P1And GePerforming step 7;
step 6: solving to obtain { P1,GeThe exact solution of;
and 7: interfering with the transmitter Tx according to the least-squares principle1From the above calculation, a plurality of { P }1,GeCombine with CiOne group of matches, denoted as
Figure FDA0002275475940000031
Namely, it is
Figure FDA0002275475940000032
Wherein n represents the nth { P's obtained by the interference management method based on backward internal and external cascade precoding1,GeThe solution of.
3. The method for managing interference based on backward inner and outer cascade precoding as claimed in claim 2, wherein said step 3 comprises:
(1) for modulation symbol set S ═ S1,s2,…,sLIntroduce arbitrary symbols in S
Figure FDA0002275475940000033
As a reference symbol, define
Figure FDA0002275475940000034
(2)GeSatisfy the requirement of
Figure FDA0002275475940000035
Will be conditional
Figure FDA0002275475940000036
Deformation to H10GePe＝αd⊥Wherein d is⊥Representation and Tx0To Rx0A unit vector in which the transmitted signals are orthogonal;
(3) equation pair H10GePe＝αd⊥Left multiplication matrix H with two ends10Contrary to (2)
Figure FDA0002275475940000037
If H is present10Not a square matrix, then
Figure FDA0002275475940000038
From H10Pseudo-inverse of
Figure FDA0002275475940000039
Instead of;
(4) defining a vector
Figure FDA00022754759400000310
To obtain GePeα b, wherein
Figure FDA00022754759400000311
Using elementary transformation of the rows of the matrix, from GePeObtained as α b
Figure FDA00022754759400000312
Wherein
Figure FDA0002275475940000041
And
Figure FDA0002275475940000042
respectively representing the coefficient matrix and the solution vector of the equation,
Figure FDA0002275475940000043
is that
Figure FDA0002275475940000044
The unit matrix of (a) is,
Figure FDA0002275475940000045
represents GeThe (c) th column of (a),
Figure FDA0002275475940000046
(5) calculation of GeThe general solution expression of (c) is:
Figure FDA0002275475940000047
4. an interference management device based on backward internal and external cascade precoding, comprising a device for executing the interference management method based on backward internal and external cascade precoding in any claim 1-3.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130028068A1 (en) * 2010-04-05 2013-01-31 Pantech Co., Ltd. Channel state information feedback device, method thereof, and base station
US20140064109A1 (en) * 2012-08-31 2014-03-06 Motorola Mobility Llc Method and apparatus for mitigating downlink interference
CN104052697A (en) * 2014-05-09 2014-09-17 重庆邮电大学 Interference alignment method based on two-layer pre-coding structure in MIMO-IBC system
CN106603135A (en) * 2016-12-29 2017-04-26 重庆邮电大学 Iterative interference alignment method based on double-layer precoding in multi-user MIMO interference system
CN109088664A (en) * 2018-09-06 2018-12-25 西安电子科技大学 Self-interference suppressing method based on block diagonalization and triangle decomposition
CN109905155A (en) * 2019-01-21 2019-06-18 郑州轻工业学院 A kind of interference management method, wireless communication system based on inside and outside cascade precoding

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130028068A1 (en) * 2010-04-05 2013-01-31 Pantech Co., Ltd. Channel state information feedback device, method thereof, and base station
US20140064109A1 (en) * 2012-08-31 2014-03-06 Motorola Mobility Llc Method and apparatus for mitigating downlink interference
CN104052697A (en) * 2014-05-09 2014-09-17 重庆邮电大学 Interference alignment method based on two-layer pre-coding structure in MIMO-IBC system
CN106603135A (en) * 2016-12-29 2017-04-26 重庆邮电大学 Iterative interference alignment method based on double-layer precoding in multi-user MIMO interference system
CN109088664A (en) * 2018-09-06 2018-12-25 西安电子科技大学 Self-interference suppressing method based on block diagonalization and triangle decomposition
CN109905155A (en) * 2019-01-21 2019-06-18 郑州轻工业学院 A kind of interference management method, wireless communication system based on inside and outside cascade precoding

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