WO2016034051A1 - Interference suppression method and device - Google Patents

Abstract

Disclosed are an interference suppression method and device for solving the problem that an SLIC or ML receiver cannot be used to eliminate interference because a PMI cannot be estimated precisely. The method comprises: acquiring channel parameters, which comprise a first channel matrix corresponding to a serving cell and a second channel matrix corresponding to an interfering cell; performing equivalent transformation on a received signal to obtain y=H ₀ x ₀ +H̃ _I P _I x _I +n, where y is the received signal, x ₀ is a first transmission signal sent by the serving cell, x _I is a second transmission signal sent by the interfering cell, n is a noise signal, H ₀ is the product of the first channel matrix and a pre-coding matrix corresponding to the serving cell, H̃ _I is the second channel matrix, and P _I is a pre-coding matrix corresponding to the interfering cell; and using the product of P _I and x _I as an equivalent transmission signal, and performing demodulation processing on the received signal after the equivalent transformation, so as to eliminate the interference of the equivalent transmission signal on a premise that a coefficient of the pre-coding matrix corresponding to the interfering cell is not acquired.

Description

Interference suppression method and device Technical field

The present invention relates to the field of communications technologies, and in particular, to an interference suppression method and apparatus.

Background technique

The growing demand for personal communications by users is driving the evolution of wireless transmission technologies. At the end of 2004, the 3rd Generation Partnership Project (3GPP) began the Long Term Evolution (LTE) project of the Universal Mobile Telecommunications System (UMTS) technology. In the actual scenario of the LTE, the user equipment (User Equipment, UE) may be interfered by the neighboring cell or interfered by the paired user in the cell, and the interference will seriously degrade the performance of the UE demodulation data channel. The high density and heterogeneity of the base station is the evolution direction of the LTE network structure, which obviously brings more serious inter-cell interference between cells and multiple users.

A standard receiver that suppresses interference is defined in the Release 11 phase of the LTE release, such as an Interference Rejection Combining (IRC) receiver. However, the ability of IRC to suppress inter-cell interference is limited, and interference between users cannot be suppressed at all. Therefore, an enhanced interference suppression receiver, namely, a Symbol Level Interference Cancellation (SLIC) receiver and a Maximum Likelihood (ML) receiver, is defined in the LTE Release 12. Both types of receivers have better ability to suppress inter-user and inter-cell interference. However, both types of receivers require certain parameters of known interference signals, such as modulation order, transmission mode, and Pre-coder Matrix Indicator (PMI), etc., and these parameters need to be estimated by the UE.

In the LTE Multiple-Input Multiple-Output (MIMO)-Orthogonal Frequency Division Multiplex (OFDM) system, it is assumed that the number of receiving antennas on the UE side is N, and x, y, and H are respectively used. A transmission signal, a received signal, and an equivalent frequency domain channel matrix (including a precoding indicated by the PMI) indicating a resource element (Resource Element, RE) in the frequency domain Matrix), then the channel model can be expressed as:

y=Hx+n (1)

Where n is assumed to be N-dimensional additive white Gaussian noise (mean value 0, covariance matrix is σ2I); x is an L-dimensional column vector (L represents the total number of layers of the transmitted signal (ie, the rank of the transmitted signal), including the service Cell and all interfering cells to be eliminated), ie x=[x ₁ ,x ₂ ,...,x _L ] ^T , channel matrix H=[h ₁ ,h ₂ ,...,h _L ](h _k is N-dimensional column Vector, representing the equivalent frequency domain channel corresponding to the kth transmitted symbol).

In order to distinguish signals and channels of multiple cells, x and H can be split into two parts, namely:

y=H ₀ x ₀ +H _I x _I +n (2)

Wherein, the 0 subscript indicates the serving cell, and the I subscript indicates the interfering cell without loss of generality. It is assumed that the pre-B layer transmission symbol is derived from the serving cell, and the transmission symbols from the B+1 layer to the Lth layer are derived from other interfering cells (may be It is an interfering cell, or it can be multiple interfering cells) or other UEs paired with the same cell, ie H ₀ =[h ₁ ,h ₂ ,...,h _B ], H _I =[h _B+1 ,h _{B+ 2} ,...,h _L ],x ₀ =[x ₁ ,x ₂ ,...,x _B ] ^T and x _I =[x _B+1 , x _B+2 ,...,x _L ] ^T .

The energy algorithm or the generalized maximum likelihood algorithm is usually used to estimate the PMI parameters of the interference.

1, energy algorithm:

R _yy =E(yy ^H ) (3b)

Where P _I is the precoding matrix corresponding to the interfering cell, σ is the noise power, the summation in (3a) is performed on all RE samples, and the mathematical expectation in (3b) can be obtained by algebraic averaging of the samples.

2. Generalized maximum likelihood algorithm:

For Transmission Mode (TM) 3 and TM4, when the interference signal uses 2 ports and the number of layers is 2, or 4 ports are used and the number of layers is 4, regardless of the value of the PMI corresponding to the interfering cell,

Both are unit matrices. Therefore, neither the energy method nor the generalized maximum likelihood method can accurately estimate the PMI corresponding to the interfering cell. Due to the above scenario, the PMI corresponding to the interfering cell cannot be accurately estimated. Therefore, the SLIC or ML receiver cannot be used to eliminate interference, thereby limiting the ability of the UE receiver to suppress interference.

Summary of the invention

An embodiment of the present invention provides an interference suppression method and apparatus, which are used to solve the PMI corresponding to an interfering cell because the interfering signal uses two ports and the number of layers is two, or four ports are used and the number of layers is four. This causes the problem that the SLIC or ML receiver cannot be used to eliminate interference.

In a first aspect, an interference suppression method includes:

Obtaining a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

Equivalent transformation of the received signal

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell;

The product of P _I x _I is used as an equivalent transmission signal, and the equivalent transformed received signal is demodulated to eliminate the equivalent without acquiring the coefficients of the precoding matrix corresponding to the interfering cell. The interference of the transmitted signal.

With reference to the first aspect, in a first possible implementation, before demodulating the equivalent transformed received signal, the method further includes: determining the equivalent according to a modulation manner adopted by the second transmit signal a constellation diagram corresponding to the transmitted signal;

Determine the demodulation method used in the demodulation process according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

If the determined number of constellation points is greater than a set threshold, determining to adopt the first demodulation method Transmitting a signal to perform demodulation processing, wherein the first demodulation mode comprises minimum mean square error MMSE demodulation; or, if the determined number of constellation points is less than or equal to the threshold, determining to adopt a second demodulation mode pair The transmit signal is subjected to a demodulation process, wherein the second demodulation mode includes symbol level interference cancellation SLIC demodulation and maximum likelihood ML demodulation.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in the second possible implementation manner, if the SLIC demodulation is used, the equivalent transformed received signal is demodulated, including:

Determining the mean and variance of each layer of the equivalent transmit signal in each demodulation according to the following formula;

Determining a log likelihood ratio LLR value of each layer of the equivalent transmit signal in each demodulation according to the obtained mean and variance;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

{x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the first transmitted signal The total number of layers.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a third possible implementation manner, if the SLIC demodulation is used, the equivalent transformed received signal is demodulated, including:

Equivalently transmitting the equivalent of the constellation point in the constellation corresponding to the equivalent transmit signal The constellation points in the constellation corresponding to the radio signal are divided into M groups to be able to multiplex the LLR and the mean value of the constellation points in the constellation corresponding to the second transmission signal when calculating the LLR, the mean and the variance of each set of constellation points. And variance;

For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation, the calculated mean values of each set of constellation points are combined according to the following formula to obtain each layer of the equivalent transmit signal. The mean value of the SLIC demodulation at this time:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j ∈ {B +1, ..., L}, and L indicates reception The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

In conjunction with the third possible implementation of the first aspect, in a fifth possible implementation, the calculated variance of each set of constellation points is combined according to the following formula to obtain each layer in the equivalent transmit signal. The variance of the signal in this SLIC demodulation:

Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j=B+1, ..., L, L represents the received transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a sixth possible implementation, if ML demodulation is used, demodulating the equivalent transformed received signal includes:

And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal;

Determining, according to the node selection method, the ML demodulation method according to the second transmission signal, selecting a set number of nodes from each set of constellation points;

Selecting a final node for each bit signal in each layer of the equivalent transmit signal from among the selected nodes;

The LLR value of each bit signal in each layer of the equivalent transmitted signal is calculated based on the selected final node.

With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation, selecting a final signal for each bit signal in each layer of the equivalent transmit signal from the selected nodes Nodes, including:

Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing a prior probability corresponding to the mean of the equivalent transmitted signal, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L representing the transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the seventh possible implementation manner of the first aspect, in an eighth possible implementation, each bit in each layer of the equivalent transmit signal is calculated according to the following formula according to the selected final node. The LLR value of the signal:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

In conjunction with the third possible implementation of the first aspect, or the sixth possible implementation of the first aspect, in a ninth possible implementation, the constellation in the constellation corresponding to the equivalent transmit signal The position of the point, the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, including:

And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

In a second aspect, an interference suppression device includes:

An acquiring module, configured to acquire a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

An equivalent transformation module for performing equivalent transformation on the received signal

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell;

a demodulation module, configured to use a product of P _I x _I as an equivalent transmission signal, and perform demodulation processing on the equivalent transformed received signal, so as not to acquire coefficients of a precoding matrix corresponding to the interfering cell Eliminating interference from the equivalent transmitted signal.

With reference to the second aspect, in a first possible implementation manner, the demodulation module performs an equivalent transformation Before the received signal is subjected to the demodulation process, the method further includes: determining, according to the modulation mode adopted by the second transmit signal, a constellation corresponding to the equivalent transmit signal;

The demodulation module determines a demodulation method used in the demodulation process according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.

With reference to the second aspect, or the first possible implementation manner of the second aspect, in the second possible implementation manner, if the SLIC demodulation is adopted, the demodulation module demodulates the equivalent transformed received signal Processing, including:

Determining, according to the following formula, the mean and variance of each layer of the equivalent transmit signal in each demodulation; and determining each layer of the equivalent transmit signal in each demodulation based on the obtained mean and variance Log likelihood ratio LLR value;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

{x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the first transmitted signal The total number of layers.

With reference to the second aspect, or the first possible implementation manner of the second aspect, in a third possible implementation, if the SLIC demodulation is adopted, the demodulation module demodulates the equivalent transformed received signal Processing, including:

Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.

In conjunction with the third possible implementation of the second aspect, in a fourth possible implementation, the demodulation module combines the calculated mean values of each set of constellation points to obtain the equivalent emission according to the following formula The average value of each layer of the signal in the SLIC demodulation:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j ∈ {B +1, ..., L}, and L indicates reception The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

With reference to the third possible implementation manner of the second aspect, in a fifth possible implementation, the demodulation module combines the calculated variances of each set of constellation points according to the following formula to obtain the equivalent emission. The variance of each layer of signal in the signal during this SLIC demodulation:

_Where, Var (x _j) represents the time equivalent of the SLIC demodulated signal layer j of the transmit signal variance, Var (Ω _m) denotes the variance of the constellation points of the m-th group, Pr (Ω _m) denotes the m The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j=B+1, ..., L, L represents the received transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the second aspect, or the first possible implementation manner of the second aspect, in a sixth possible implementation, if the ML demodulation is adopted, the demodulation module demodulates the equivalent transformed received signal Processing, including:

And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal; and performing ML demodulation according to the second transmit signal The node selection method used, respectively, selects a set number of nodes from each set of constellation points; and selects each bit signal in each layer of the equivalent transmit signal from the selected nodes respectively a final node; and calculating an LLR value for each of the bit signals in each layer of the equivalent transmitted signal based on the selected final node.

With reference to the sixth possible implementation manner of the second aspect, in a seventh possible implementation, the demodulation module, from among the selected nodes, is each of the signals of the equivalent transmit signal The bit signals select the final node, including:

Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing a prior probability corresponding to the mean of the equivalent transmitted signal, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L representing the transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the seventh possible implementation of the second aspect, in an eighth possible implementation, the demodulation module calculates, according to the selected final node, each layer of the equivalent transmit signal according to the following formula The LLR value of each bit signal in:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

With reference to the third possible implementation manner of the second aspect, or the sixth possible implementation manner of the second aspect, in a ninth possible implementation manner, the demodulation module is configured according to the equivalent transmit signal The position of the constellation point in the constellation diagram divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups, including:

And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

A third aspect is a communication device, the communication device comprising:

a processor, configured to acquire a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

a receiver for equivalently transforming a received signal to obtain

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell; and the product of P _I x _I is used as an equivalent transmit signal, and the equivalent transformed received signal is demodulated to Acquiring the interference of the equivalent transmit signal on the premise of acquiring the coefficients of the precoding matrix corresponding to the interfering cell.

With reference to the third aspect, in a first possible implementation, before the receiver performs demodulation processing on the equivalent transformed received signal, the receiver is further configured to: determine, according to a modulation manner adopted by the second transmit signal, Generating a constellation corresponding to the equivalent transmit signal;

The receiver determines the demodulation method used in the demodulation process according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in the second possible implementation manner, if the SLIC demodulation is adopted, the receiver performs demodulation processing on the equivalent transformed received signal. ,include:

Determining, according to the following formula, the mean and variance of each layer of the equivalent transmit signal in each demodulation; and determining each layer of the equivalent transmit signal in each demodulation based on the obtained mean and variance Log likelihood ratio LLR value;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

{x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the first transmitted signal The total number of layers.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in a third possible implementation, if the SLIC demodulation is adopted, the receiver performs demodulation processing on the equivalent transformed received signal. ,include:

Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.

In conjunction with the third possible implementation of the third aspect, in a fourth possible implementation, the receiver combines the calculated mean values of each set of constellation points to obtain the equivalent transmit signal according to the following formula The average value of each layer of the SLIC demodulation at this time:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j ∈ {B +1, ..., L}, and L indicates reception The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

With reference to the third possible implementation manner of the third aspect, in a fifth possible implementation manner, the receiver combines the calculated variances of each set of constellation points according to the following formula to obtain the equivalent transmit signal. The variance of each layer of signals in this SLIC demodulation:

Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j=B+1, ..., L, L represents the received transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in a sixth possible implementation, if the ML demodulation is adopted, the receiver performs demodulation processing on the equivalent transformed received signal. ,include:

And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal; and performing ML demodulation according to the second transmit signal The node selection method used, respectively, selects a set number of nodes from each set of constellation points; and selects each bit signal in each layer of the equivalent transmit signal from the selected nodes respectively a final node; and calculating an LLR value for each of the bit signals in each layer of the equivalent transmitted signal based on the selected final node.

With reference to the sixth possible implementation manner of the third aspect, in a seventh possible implementation, the receiver, from among the selected nodes, is each of the signals of each layer of the equivalent transmit signal The bit signal selects the final node, including:

Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing a prior probability corresponding to the mean of the equivalent transmitted signal, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L representing the transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

With reference to the seventh possible implementation manner of the third aspect, in an eighth possible implementation manner, the receiver calculates, according to the selected final node, each layer of the equivalent transmit signal according to the following formula The LLR value of each bit signal:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

With reference to the third possible implementation manner of the third aspect, or the sixth possible implementation manner of the third aspect, in a ninth possible implementation manner, the receiver is configured according to the constellation corresponding to the equivalent transmit signal The position of the constellation point in the figure divides the constellation points in the constellation corresponding to the equivalent transmission signal into M groups, including:

And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

In the method, the device, and the communication device provided by the embodiments of the present invention, when the received signal is demodulated, the product of the precoding matrix corresponding to the interfering cell and the second transmit signal sent by the interfering cell is used as an equivalent transmit signal, and directly Eliminate the interference of the equivalent transmitted signal. Since the precoding matrix corresponding to the interfering cell is considered in the second transmit signal, it is not necessary to consider the precoding matrix corresponding to the interfering cell in the channel estimation, so that the channel corresponding to the interference cell is not estimated when performing channel estimation. The correct value of the PMI of the coding matrix improves the receiver's ability to suppress interference and improves the throughput performance of the terminal.

DRAWINGS

1 is a schematic diagram of an interference suppression method according to an embodiment of the present invention;

2A is a constellation diagram corresponding to a second transmit signal according to an embodiment of the present invention;

2B is a constellation diagram corresponding to an equivalent transmit signal according to an embodiment of the present invention;

3 is a schematic diagram of a SLIC demodulation process according to an embodiment of the present invention;

4 is a schematic diagram of an ML demodulation process according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an interference suppression apparatus according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a communications device according to an embodiment of the present invention.

detailed description

The present invention considers the precoding matrix indicated by the PMI in the transmitted signal, and does not consider the precoding matrix indicated by the PMI in the channel estimation. Since the channel estimation does not estimate the correct value of the PMI, the receiver suppresses interference. The ability to improve the throughput performance of the terminal.

The embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It is to be understood that the embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in FIG. 1 , an interference suppression method provided by an embodiment of the present invention includes:

S11. Obtain a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell.

In this step, according to the channel estimation, the first channel matrix corresponding to the serving cell can be directly acquired.

a second channel matrix corresponding to the interfering cell

The first channel matrix and the second channel matrix are both channel matrices that do not include a precoding matrix.

S12. Perform equivalent transformation on the received signal to obtain

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix

The product of the precoding matrix P ₀ corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell. H ₀

In this step, the precoding matrix P ₀ corresponding to the serving cell is a known amount, and the precoding matrix P _I corresponding to the interfering cell is an amount that cannot be correctly estimated.

S13. Using the product of P _I x _I as an equivalent transmit signal, performing demodulation processing on the equivalent transformed received signal, so as to eliminate the coefficient of the precoding matrix corresponding to the interfering cell. The interference of the equivalent transmitted signal.

In the embodiment of the present invention, when the demodulation process is performed, the product of the precoding matrix corresponding to the interfering cell and the second transmit signal sent by the interfering cell is used as an equivalent transmit signal, and the interference of the equivalent transmit signal is directly eliminated. Since the precoding matrix corresponding to the interfering cell is considered in the second transmit signal, it is not necessary to consider the precoding matrix corresponding to the interfering cell in the channel estimation, so that the channel corresponding to the interference cell is not estimated when performing channel estimation. The correct value of the PMI of the coding matrix improves the receiver's ability to suppress interference and improves the throughput performance of the terminal.

In the embodiment of the present invention, various signals (including a transmit signal, a first transmit signal, a second transmit signal, an equivalent transmit signal, a noise signal, etc.) are all represented in the form of a vector.

The channel model used in the embodiment of the present invention will be described below. For the formula (2) in the background art, the formula (2) can be rewritten as follows:

among them,

a second channel matrix corresponding to the interfering cell obtained by the channel estimation, that is, a channel matrix that does not include a precoding matrix corresponding to the interfering cell,

For the equivalent emission signal of interference, specific:

Obviously, the expression of the jth layer (L ≥ j ≥ B + 1) of the equivalent transmitted signal is as follows:

Wherein, α _i in the formula (4c) is a vector in the precoding matrix P _I corresponding to the interfering cell, and it can be seen that the jth layer of the equivalent transmit signal is the original transmit signal (ie, the second transmit signal) of the interfering cell. A linear combination of all layers (ie (B+1) to L layers) signals.

As can be seen from equation (4a), the receiver can put the equivalent symbol

It is regarded as a transmission signal transmitted by the interfering cell. For example, SLIC and ML detection are performed according to formula (4a), so that there is no influence of the PMI corresponding to the interfering cell in the process of demodulation.

In the implementation, when the equivalent-converted received signal is demodulated in S13, the SLIC, ML, or Minimum Mean Square Error (MMSE) may be used for demodulation. The specific demodulation method can be specified in the standard protocol, or the demodulation method used in the factory setting, the demodulation method used in the network side configuration, and the additional signaling indication. The demodulation method used is not limited herein.

When the modulation order of the second transmission signal is higher (such as 64QAM) or the number of layers of the second transmission signal is larger (such as the number of layers is 4),

The number of constellation points in the corresponding constellation diagram will be many, and the additional complexity overhead caused by this will become negligible. In order to further reduce the implementation complexity, preferably, the demodulation method used in the demodulation process in S13 is determined according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmission signal;

If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation mode includes MMSE demodulation; or, if it is determined The number of constellation points is less than or equal to a set threshold, and determining to perform demodulation processing on the transmit signal by using a second demodulation method, where the second demodulation mode includes SLIC demodulation and ML demodulation.

Specifically, the MMSE demodulation is actually an iterative SLIC demodulation, that is, the LLR value is calculated by the following formula:

among them,

V=diag(Var(x ₁ ),...,Var(x _j ),...,Var(x _L ));

The mean and variance in the above expression take values 0 and 1, respectively, ie E(x _k )=0, Var(x _j )=1.

The autocorrelation matrix of the precoding matrix corresponding to the interfering cell, because the 2 port layer is 2 or the 4 port layer is 4, and the correct value of the PMI corresponding to the interfering cell cannot be estimated.

Is the unit matrix, then:

It can be seen that the MMSE demodulation does not require interference with the PMI parameters of the signal.

In the implementation, when the demodulation method used in the demodulation process is determined, the threshold used is an empirical value, and an optimal threshold can be determined by simulation or the like.

In the implementation, before determining the demodulation mode used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal, the method further includes:

The constellation corresponding to the equivalent transmit signal is determined according to the modulation mode adopted by the second transmit signal.

Specifically, since the equivalent transmit signal is used in the embodiment of the present invention to replace the original transmit signal (ie, the second transmit signal) of the interfering cell, the impact of the precoding matrix corresponding to the interfering cell is considered in the equivalent transmit signal. The constellation diagram corresponding to the equivalent transmit signal is different from the constellation corresponding to the second transmit signal. Taking the QPSK mode as an example, for a scenario where the 2-port layer is 2, the constellation corresponding to the second transmit signal is as shown in FIG. 2A. The constellation diagram corresponding to the equivalent transmit signal is shown in FIG. 2B. It can be seen from the figure that the constellation of the second transmit signal transmitted by the interfering cell changes due to the influence of the precoding matrix corresponding to the interfering cell. Although different transmission modes use different PMI parameters, as long as the number of ports used for transmitting the signal and the number of layers of the transmitted signal and the modulation and demodulation method used for transmitting the signal are determined, the constellation corresponding to the equivalent emission signal of the interference is not As the value of PMI changes.

Based on any of the foregoing embodiments, as a first implementation manner, if SLIC demodulation is used in S13, demodulation processing is performed on the equivalent transformed received signal, including:

Determining the mean and variance of each layer of the equivalent transmit signal for each demodulation according to the following formula;

Determining the pair of signals of each layer of the equivalent transmitted signal in each demodulation according to the obtained mean and variance Number likelihood ratio LLR value;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E(x _j ) Priori probability,

{x _j } represents all possible points of the j-th layer signal of the equivalent transmitted signal in the constellation corresponding to the equivalent transmitted signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the total number of layers of the first transmitted signal .

Based on any of the foregoing embodiments, as a second implementation manner, if SLIC demodulation is used in S13, demodulation processing is performed on the equivalent transformed received signal, including:

According to the position of the constellation point in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, which can be complexed when calculating the LLR, mean and variance of each set of constellation points. LLR, mean and variance of constellation points in the constellation corresponding to the second transmitted signal;

For each demodulation in SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the last demodulated LLR value; the calculated mean values of each set of constellation points are combined to obtain the demodulated The mean value is obtained by combining the calculated variances of each set of constellation points to obtain a variance of the demodulation; and according to the mean and variance of the demodulation, the LLR value of the demodulation is calculated.

The specific processing is shown in Figure 3. For the ith SLIC demodulation, the LLR, mean and variance of each constellation point are calculated separately, and the LLR, mean and variance of each constellation point can be multiplexed with the second transmission. The LLR, mean and variance calculation results of the constellation points of the signal), and then combine the mean and variance of all the constellation points to obtain the final mean and variance, wherein the i+1th SLIC demodulation needs to be called during processing. The final mean and variance obtained from the i-th SLIC demodulation process.

In this implementation manner, before the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, the method further includes:

The constellation corresponding to the equivalent transmit signal is determined according to the modulation mode adopted by the second transmit signal.

In this implementation, the calculated mean values of each set of constellation points are combined according to the following formula to obtain the mean value of each layer of the SLIC demodulation signal of the equivalent transmitted signal:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability of the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j∈{B+1, ..., L}, and L represents the received The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

In this implementation, the calculated variance of each set of constellation points is combined according to the following formula to obtain the variance of each layer of the equivalent transmitted signal in the SLIC demodulation:

Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j∈{B+1, ..., L}, and L represents the received transmission. The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

In this implementation manner, according to the position of the constellation point in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, including but not limited to one of the following manners. :

In the constellation points in the constellation corresponding to the equivalent transmitting signal, the constellation points in the constellation corresponding to the second transmitting signal are divided into a group by rotating the same angle;

a constellation corresponding to the constellation corresponding to the corresponding transmitted signal, the constellation corresponding to the second transmitted signal The constellation points in the figure are divided into a group by compressing the same compression amount to obtain constellation points;

In the constellation points in the constellation corresponding to the equivalent transmission signal, the constellation points in the constellation corresponding to the second transmission signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

It should be noted that, among the constellation points in the constellation diagram corresponding to the equivalent transmission signal, the constellation points located at the origin of the constellation diagram are divided into a group, and the mean value and the variance are both zero.

For example, the flow of the mean value and the variance in the second implementation mode will be described by taking the shape of the constellation point shown in FIG. 2B as an example. The constellation points in the constellation diagram shown in FIG. 2B can be divided into three groups, that is, the constellation points indicated by "●" (the constellation points indicated by Ω _b ) and the constellation points indicated by "ο" (the group is represented by Ω _r ) Constellation points) and constellation points represented by "△" (the set of constellation points are represented by Ω _g ).

Ω _b is the constellation point in the constellation corresponding to the second transmission signal shown in FIG. 2A, and the LLR, the mean value and the variance of the group of constellation points are the LLR, the mean value of the constellation points in the constellation corresponding to the second transmission signal, respectively. Variance; each constellation point in Ω _r can be seen as a 45-degree rotation of each constellation point in the constellation corresponding to the second transmitted signal shown in FIG. 2A.

Obtaining, therefore, when calculating the LLR, the mean value and the variance of the constellation points of the constellation points in the constellation corresponding to the second transmission signal, the group constellation points are rotated clockwise by 45 degrees. And zoom in

Times, the constellation points in the constellation corresponding to the second transmission signal are obtained. At this time, the LLR value of the constellation points of the group is the LLR value of the constellation points in the constellation corresponding to the second transmission signal, and then according to the LLR value. Calculate the mean and variance of the set of constellation points, and finally rotate the resulting mean by 45 degrees and compress

The obtained variance is compressed to 1/2 of the original, and the mean and variance of each constellation point in Ω _r are obtained; the mean and variance of the constellation points in Ω _g are both zero.

According to formula (4c), the prior probabilities of the above three sets of constellation points are: Pr(Ω _b )=1/4, Pr(Ω _r )=1/2, Pr(Ω _g )=1/4, then :

Since E(Ω _g )=0, therefore,

In this implementation manner, since the LLR, the mean value, and the variance of the constellation points in the constellation corresponding to the second transmit signal can be multiplexed when calculating the mean and variance of each set of constellation points, the implementation complexity is low.

Based on any of the foregoing embodiments, as a third implementation manner, if ML demodulation is adopted in S13, demodulation processing is performed on the equivalent transformed received signal, including:

Selecting, from the constellation points in the constellation corresponding to the equivalent transmit signal, a node that satisfies the set condition, and determining the selected node as a node of each bit signal in each layer of the equivalent transmit signal; as well as

Calculating an LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected node;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing the prior probability corresponding to the mean of the equivalent transmitted signal, y is the received signal, H is the channel matrix, x is the second transmitted signal, j=B+1, ..., L, L is the total layer of the transmitted signal Number, B represents the total number of layers of the first transmitted signal.

In this implementation, according to the selected node, the LLR value of each bit signal in each layer of the equivalent transmit signal is calculated according to the following formula:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

Based on any of the foregoing embodiments, as a fourth implementation manner, if ML demodulation is adopted in S13, demodulation processing is performed on the equivalent transformed received signal, including:

Dividing the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal;

a node selection method used for performing ML demodulation according to the second transmission signal, and selecting a set number of nodes from each set of constellation points;

Selecting a final node for each bit signal in each layer of the equivalent transmitted signal from among the selected nodes;

The LLR value of each bit signal in each layer of the equivalent transmitted signal is calculated based on the selected final node.

The specific processing is shown in Figure 4. First, do pre-processing, such as QR decomposition; then, make node selection for the PMI known layer (ie, the front B layer x ₁ , x ₂ ,..., x _B ); then the PMI is unknown. Layer to do node selection (ie

), that is, node selection is performed for each set of constellation points (when performing node selection, each group of constellation points can reuse the node selection method of QPSK, 16QAM or 64QAM in the original ML receiver); then, the final node selection is performed. The final node selection needs to consider the offset

In this implementation manner, before the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, the method further includes:

The constellation corresponding to the equivalent transmit signal is determined according to the modulation mode adopted by the second transmit signal.

In this implementation manner, according to the position of the constellation point in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, including but not limited to one of the following modes:

In the constellation points in the constellation corresponding to the equivalent transmitting signal, the constellation points in the constellation corresponding to the second transmitting signal are divided into a group by rotating the same angle;

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by compressing the same compression amount;

In the constellation points in the constellation corresponding to the equivalent transmission signal, the constellation points in the constellation corresponding to the second transmission signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

It should be noted that, among the constellation points in the constellation diagram corresponding to the equivalent transmission signal, the constellation points located at the origin of the constellation diagram are divided into a group, and the mean value and the variance are both zero.

In this implementation, from the selected nodes, the final node is selected for each bit signal in each layer of the equivalent transmit signal, including:

From the selected nodes, select the node that meets the set conditions and select the node to be selected. Determining a final node for each bit signal in each layer of signals that are equivalent to the transmitted signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Indicates the prior probability corresponding to the mean of the equivalent transmitted signal, y denotes the received signal, H denotes the channel matrix, x denotes the second transmitted signal, j=B+1, ..., L, L denotes the received transmitted signal The total number of layers, B represents the total number of layers of the first transmitted signal.

In this implementation, according to the selected final node, the LLR value of each bit signal in each layer of the equivalent transmit signal is calculated according to the following formula:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

For example, the flow of the ML demodulation in the fourth implementation manner will be described by taking the shape of the constellation point shown in FIG. 2B as an example. The constellation points in the constellation diagram shown in FIG. 2B can be divided into three groups, that is, the constellation points indicated by "●" (the constellation points indicated by Ω _b ) and the constellation points indicated by "ο" (the group is represented by Ω _r ) Constellation points) and constellation points represented by "△" (the set of constellation points are represented by Ω _g ).

Ω _b is the constellation point in the constellation corresponding to the second transmitted signal shown in FIG. 2A, and the set of constellation points can multiplex the node selection method in the original ML demodulation mode (ie, select ||y-Hx|| ² The smaller nodes can usually be implemented by look-up table method, assuming that two nodes are finally selected; each constellation point in Ω _r can be regarded as the constellation corresponding to the second transmitted signal shown in FIG. 2A. Each constellation point rotates 45 degrees and then zooms out

Obtained, therefore, the set of constellation points in the multiplexed original ML demodulation mode node selection method for node selection, first rotate the set of constellation points clockwise 45 degrees and zoom

Times, the constellation points in the constellation corresponding to the second transmitted signal are obtained. At this time, the node selection method in the original ML demodulation mode is reused for node selection, and it is assumed that two nodes are finally selected; only one of the Ω _g Point, there is no need to reuse the node selection method in the original ML demodulation mode for node selection. After the packet selection, a total of five nodes are selected. Finally, the node corresponding to each bit of the jth layer of the equivalent transmission signal is selected from the five nodes, and the LLR value of the bit signal is calculated.

In this implementation manner, since the node selection method in the original ML demodulation mode can be multiplexed when the node selection is performed at the group constellation point, the implementation complexity is low.

The above method processing flow can be implemented by a software program, which can be stored in a storage medium, and when the stored software program is called, the above method steps are performed.

Based on the same inventive concept, an interference suppression device is also provided in the embodiment of the present invention. The principle of solving the problem is similar to the interference suppression method. Therefore, the implementation of the device can refer to the implementation of the method. .

An interference suppression device provided by an embodiment of the present invention, as shown in FIG. 5, the device includes:

The obtaining module 51 is configured to acquire a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

The equivalent conversion module 52 performs equivalent transformation on the received signal to obtain

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell;

The demodulation module 53 is configured to use the product of P _I x _I as an equivalent transmission signal, and perform demodulation processing on the equivalent transformed received signal, so as not to acquire the coefficient of the precoding matrix corresponding to the interfering cell. Next, the interference of the equivalent transmitted signal is eliminated.

The device provided by the embodiment of the present invention may be located in the terminal device or in the network device.

In the embodiment of the present invention, various signals (including a transmit signal, a first transmit signal, a second transmit signal, an equivalent transmit signal, a noise signal, etc.) are all represented in the form of a vector.

In the implementation, when the demodulation module 53 demodulates the equivalent-transformed received signal, the demodulation may be performed by using SLIC, ML, or Minimum Mean Square Error (MMSE). Which demodulation method is specifically adopted, which can be specified in the standard protocol or The demodulation method used in the factory setting specification may be configured by the network side, and the demodulation method used may be indicated by additional signaling, which is not limited herein.

When the modulation order of the second transmission signal is higher (such as 64QAM) or the number of layers of the second transmission signal is larger (such as the number of layers is 4),

The number of constellation points in the corresponding constellation diagram will be many, and the additional complexity overhead caused by this will become negligible. In order to further reduce the implementation complexity, the demodulation module 53 is further configured to determine, according to the modulation mode adopted by the second transmit signal, the demodulation module 53 before performing the demodulation process on the equivalent transformed signal. a constellation diagram corresponding to the effective transmission signal;

The demodulation module 53 determines the demodulation method used in the demodulation process according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.

It should be noted that although different transmission modes use different PMI parameters, as long as the number of ports used for transmitting signals and the number of layers of the transmitted signals, and the modulation and demodulation method used by the transmitted signals are determined, the equivalent emission signals of the interferences are corresponding. The constellation diagram does not change with the value of the PMI.

In the implementation, when the demodulation method used in the demodulation process is determined, the threshold used is an empirical value, and an optimal threshold can be determined by simulation or the like.

Based on any of the foregoing embodiments, as a first implementation manner, if SLIC demodulation is adopted, the demodulation module 53 performs demodulation processing on the equivalent transformed received signal, including:

Determining, according to the following formula, the mean and variance of each layer of the equivalent transmit signal in each demodulation; and determining each layer of the equivalent transmit signal in each demodulation based on the obtained mean and variance Log likelihood ratio LLR value;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

{x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the first transmitted signal The total number of layers.

Based on any of the foregoing embodiments, as a second implementation manner, if SLIC demodulation is adopted, the demodulation module 53 performs demodulation processing on the equivalent transformed received signal, including:

Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.

In this implementation, the demodulation module 53 divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, and the method further includes:

Determining a constellation corresponding to the equivalent transmit signal according to a modulation manner adopted by the second transmit signal.

In this implementation, the demodulation module 53 combines the calculated mean values of each set of constellation points according to the following formula to obtain the average value of each layer of the equivalent transmit signal in the SLIC demodulation:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j ∈ {B +1, ..., L}, and L indicates reception The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

In this implementation, the demodulation module 53 combines the calculated variances of each set of constellation points according to the following formula to obtain a variance of the demodulation of each layer of the equivalent transmitted signals in the SLIC:

Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j=B+1, ..., L, L represents the received transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

In this implementation, the demodulation module 53 divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, including but not limited to the following manners. One of them:

In the constellation points in the constellation corresponding to the equivalent transmitting signal, the constellation points in the constellation corresponding to the second transmitting signal are divided into a group by rotating the same angle;

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by compressing the same compression amount;

In the constellation points in the constellation corresponding to the equivalent transmission signal, the constellation points in the constellation corresponding to the second transmission signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

It should be noted that, among the constellation points in the constellation diagram corresponding to the equivalent transmission signal, the constellation points located at the origin of the constellation diagram are divided into a group, and the mean value and the variance are both zero.

In this implementation manner, since the LLR, the mean value, and the variance of the constellation points in the constellation corresponding to the second transmit signal can be multiplexed when calculating the mean and variance of each set of constellation points, the implementation complexity is low.

Based on any of the foregoing embodiments, as a third implementation manner, if ML demodulation is adopted, the demodulation module 53 performs demodulation processing on the equivalent transformed received signal, including:

Selecting, from the constellation points in the constellation corresponding to the equivalent transmit signal, a node that satisfies the set condition, and determining the selected node as a node of each bit signal in each layer of the equivalent transmit signal; as well as

Calculating an LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected node;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing the prior probability corresponding to the mean of the equivalent transmitted signal, y is the received signal, H is the channel matrix, x is the second transmitted signal, j=B+1, ..., L, L is the total layer of the transmitted signal Number, B represents the total number of layers of the first transmitted signal.

In this implementation, the demodulation module 53 calculates the LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected node according to the following formula:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

Based on any of the foregoing embodiments, as a fourth implementation manner, if ML demodulation is adopted, the demodulation module 53 performs demodulation processing on the equivalent transformed received signal, including:

And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal; performing, according to the second transmit signal The node selection method used in ML demodulation selects a set number of nodes from each set of constellation points; and from each of the selected nodes, each of each layer of the equivalent transmit signal The bit signals select a final node; and calculate an LLR value for each bit signal in each layer of the equivalent transmitted signal based on the selected final node.

In this implementation, the demodulation module 53 selects a final node for each bit signal in each layer of the equivalent transmit signal from the selected nodes, including:

Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing a prior probability corresponding to the mean of the equivalent transmitted signal, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L representing the transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

In this implementation, the demodulation module 53 calculates the LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected final node according to the following formula:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

In this implementation, the demodulation module 53 divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, including:

And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

Based on the same inventive concept, an embodiment of the present invention provides a communication device. As shown in FIG. 6, the communication device includes:

The processor 62 is configured to acquire a module, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interfering cell;

The receiver 61 is configured to perform an equivalent transformation module for equivalent transformation of the received signal to obtain

Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell; and the product of P _I x _I is used as an equivalent transmit signal, and the equivalent transformed received signal is demodulated to Acquiring the interference of the equivalent transmit signal on the premise of acquiring the coefficients of the precoding matrix corresponding to the interfering cell; and transmitting the demodulated signal to the processor 62 for processing.

The receiver 61 and the processor 62 are connected by a bus.

The communication device provided by the embodiment of the present invention may be a terminal device or a network device.

In the embodiment of the present invention, various signals (including a transmit signal, a first transmit signal, a second transmit signal, an equivalent transmit signal, a noise signal, etc.) are all represented in the form of a vector.

In the implementation, when the receiver 61 performs demodulation processing on the equivalent-reformed received signal, demodulation can be performed by using SLIC, ML, or MMSE. The specific demodulation method can be specified in the standard protocol, or the demodulation method used in the factory setting, the demodulation method used in the network side configuration, and the additional signaling indication. The demodulation method used is not limited herein.

When the modulation order of the second transmission signal is higher (such as 64QAM) or the number of layers of the second transmission signal is larger (such as the number of layers is 4),

The number of constellation points in the corresponding constellation diagram will be many, and the extra complexity overhead caused by this will not be ignored. In order to further reduce the implementation complexity, before the receiver 61 performs demodulation processing on the equivalent transformed received signal, the receiver 61 is further configured to: determine the equivalent according to the modulation mode adopted by the second transmit signal. a constellation diagram corresponding to the transmitted signal;

The receiver 61 determines the demodulation method used in the demodulation process according to the following steps:

Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.

It should be noted that although different transmission modes use different PMI parameters, as long as the number of ports used for transmitting signals and the number of layers of the transmitted signals, and the modulation and demodulation method used by the transmitted signals are determined, the equivalent emission signals of the interferences are corresponding. The constellation diagram does not change with the value of the PMI.

In the implementation, when the demodulation method used in the demodulation process is determined, the threshold used is an empirical value, and an optimal threshold can be determined by simulation or the like.

Based on any of the foregoing embodiments, as a first implementation manner, if SLIC demodulation is adopted, the receiver 61 performs demodulation processing on the equivalent transformed received signal, including:

Determining, according to the following formula, the mean and variance of each layer of the equivalent transmit signal in each demodulation; and determining each layer of the equivalent transmit signal in each demodulation based on the obtained mean and variance Log likelihood ratio LLR value;

Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

{x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

a weighting vector representing the jth layer signal of the equivalent transmitted signal,

The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the first transmitted signal The total number of layers.

Based on any of the foregoing embodiments, as a second implementation manner, if SLIC demodulation is adopted, the receiver 61 performs demodulation processing on the equivalent transformed received signal, including:

Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.

In this implementation, the receiver 61 divides the constellation points in the constellation corresponding to the equivalent transmit signal into the M group according to the position of the constellation point in the constellation corresponding to the equivalent transmit signal, and the method further includes:

Determining a constellation corresponding to the equivalent transmit signal according to a modulation manner adopted by the second transmit signal.

In this implementation, the receiver 61 combines the calculated mean values of each set of constellation points according to the following formula to obtain the mean value of each layer of the equivalent transmitted signal in the SLIC demodulation:

Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j ∈ {B +1, ..., L}, and L indicates reception The total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.

In this implementation, the receiver 61 combines the calculated variances of each set of constellation points according to the following formula to obtain a variance of the demodulation of each layer of the equivalent transmitted signals in the SLIC:

Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean of the set of constellation points, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j=B+1, ..., L, L represents the received transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

In this implementation, the receiver 61 divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, including but not limited to the following manners. One kind:

In the constellation points in the constellation corresponding to the equivalent transmitting signal, the constellation points in the constellation corresponding to the second transmitting signal are divided into a group by rotating the same angle;

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by compressing the same compression amount;

In the constellation points in the constellation corresponding to the equivalent transmission signal, the constellation points in the constellation corresponding to the second transmission signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

It should be noted that, among the constellation points in the constellation diagram corresponding to the equivalent transmission signal, the constellation points located at the origin of the constellation diagram are divided into a group, and the mean value and the variance are both zero.

In this implementation manner, since the LLR, the mean value, and the variance of the constellation points in the constellation corresponding to the second transmit signal can be multiplexed when calculating the mean and variance of each set of constellation points, the implementation complexity is low.

Based on any of the foregoing embodiments, as a third implementation manner, if ML demodulation is adopted, the receiver 61 performs demodulation processing on the equivalent transformed received signal, including:

Selecting, from the constellation points in the constellation corresponding to the equivalent transmit signal, a node that satisfies the set condition, and determining the selected node as a node of each bit signal in each layer of the equivalent transmit signal; as well as

Calculating an LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected node;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing the prior probability corresponding to the mean of the equivalent transmitted signal, y is the received signal, H is the channel matrix, x is the second transmitted signal, j=B+1, ..., L, L is the total layer of the transmitted signal Number, B represents the total number of layers of the first transmitted signal.

In this implementation, the receiver 61 calculates the LLR value of each bit signal in each layer of the equivalent transmitted signal according to the selected node according to the selected node:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

Based on any of the foregoing embodiments, as a fourth implementation manner, if ML demodulation is adopted, the receiver 61 performs demodulation processing on the equivalent transformed received signal, including:

And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal; and performing ML demodulation according to the second transmit signal The node selection method used, respectively, selects a set number of nodes from each set of constellation points; and selects each bit signal in each layer of the equivalent transmit signal from the selected nodes respectively a final node; and calculating an LLR value for each of the bit signals in each layer of the equivalent transmitted signal based on the selected final node.

In this implementation, the receiver 61 selects a final node for each bit signal in each layer of the equivalent transmit signal from among the selected nodes, including:

Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

Where the setting condition is

{x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

Representing a prior probability corresponding to the mean of the equivalent transmitted signal, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L representing the transmission The total number of layers of the signal, B represents the total number of layers of the first transmitted signal.

In this implementation, the receiver 61 calculates the LLR value of each bit signal in each layer of the equivalent transmit signal according to the selected final node according to the following formula:

Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.

In this implementation, the receiver 61 divides the constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to the position of the constellation points in the constellation corresponding to the equivalent transmit signal, including:

And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may employ an entirely hardware embodiment, an entirely software embodiment, Or in the form of an embodiment of the software and hardware aspects. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims (20)

1. An interference suppression method, characterized in that the method comprises:

   Obtaining a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

   Equivalent transformation of the received signal

   

   Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

   

   For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell;

   The product of P _I x _I is used as an equivalent transmission signal, and the equivalent transformed received signal is demodulated to eliminate the equivalent without acquiring the coefficients of the precoding matrix corresponding to the interfering cell. The interference of the transmitted signal.
2. The method according to claim 1, wherein before performing the demodulation process on the equivalent transformed received signal, the method further comprises: determining the equivalent transmit signal according to a modulation mode adopted by the second transmit signal Corresponding constellation diagram;

   Determine the demodulation method used in the demodulation process according to the following steps:

   Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

   If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.
3. The method according to claim 1 or 2, wherein if the SLIC demodulation is used, the equivalent transformed received signal is demodulated, including:

   Determining the mean and variance of each layer of the equivalent transmit signal in each demodulation according to the following formula;

   Determining a log likelihood ratio LLR value of each layer of the equivalent transmit signal in each demodulation according to the obtained mean and variance;

   

   

   Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

   

   {x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

   

   a weighting vector representing the jth layer signal of the equivalent transmitted signal,

   

   The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the The total number of layers of the first transmitted signal.
4. The method according to claim 1 or 2, wherein if the SLIC demodulation is used, the equivalent transformed received signal is demodulated, including:

   Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

   For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.
5. The method of claim 4, wherein the calculated The mean values of each set of constellation points are combined to obtain the mean value of each layer of the equivalent transmit signal at the SLIC demodulation:

   

   Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j∈{B+1, . . . , L} L represents the total number of layers of the received transmitted signal, and B represents the total number of layers of the first transmitted signal.
6. The method according to claim 4, wherein the calculated variances of each set of constellation points are combined according to the following formula to obtain a variance of the demodulation of each layer of the equivalent transmitted signals in the SLIC:

   

   Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean value of the group constellation points, M means that the constellation points in the constellation diagram corresponding to the equivalent transmission signal are divided into M groups, j=B+1, ..., L, L The total number of layers of the received transmitted signal, B represents the total number of layers of the first transmitted signal.
7. The method according to claim 1 or 2, wherein if the ML demodulation is used, the equivalent transformed received signal is demodulated, including:

   And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal;

   Determining, according to the node selection method, the ML demodulation method according to the second transmission signal, selecting a set number of nodes from each set of constellation points;

   Selecting a final node for each bit signal in each layer of the equivalent transmit signal from among the selected nodes;

   The LLR value of each bit signal in each layer of the equivalent transmitted signal is calculated based on the selected final node.
8. The method of claim 7 wherein, from among the selected nodes, selecting a final node for each of the bit signals in each layer of the equivalent transmitted signal comprises:

   Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

   Where the setting condition is

   

   {x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

   

   Representing a prior probability corresponding to the mean of the equivalent transmitted signals, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L Indicates the total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.
9. The method according to claim 8, wherein the LLR value of each bit signal in each layer of the equivalent transmitted signal is calculated according to the selected final node according to the following formula:

   

   Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.
10. The method according to claim 4 or 7, wherein the constellation points in the constellation corresponding to the equivalent transmit signal are divided into two according to positions of constellation points in the constellation corresponding to the equivalent transmit signal. Group M, including:

    And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

    The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

    In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are rotated by the same angle and compressed by the same compression amount to obtain constellation point division As a group.
11. An interference suppression device, characterized in that the device comprises:

    An acquiring module, configured to acquire a channel parameter, where the channel parameter includes a first channel matrix corresponding to the serving cell and a second channel matrix corresponding to the interference cell;

    An equivalent transformation module for performing equivalent transformation on the received signal

    

    Where y is the received signal, x ₀ is the first transmit signal sent by the serving cell, x _I is the second transmit signal sent by the interfering cell, n is a noise signal, and H ₀ is the first channel matrix and The product of the precoding matrix corresponding to the serving cell,

    

    For the second channel matrix, P _I is a precoding matrix corresponding to the interfering cell;

    a demodulation module, configured to use a product of P _I x _I as an equivalent transmission signal, and perform demodulation processing on the equivalent transformed received signal, so as not to acquire coefficients of a precoding matrix corresponding to the interfering cell Eliminating interference from the equivalent transmitted signal.
12. The apparatus according to claim 11, wherein the demodulation module is further configured to: determine, according to a modulation mode adopted by the second transmit signal, before performing demodulation processing on the equivalent transformed received signal a constellation diagram corresponding to the equivalent transmit signal;

    The demodulation module determines a demodulation method used in the demodulation process according to the following steps:

    Determining a demodulation method used in the demodulation process according to the number of constellation points in the constellation corresponding to the equivalent transmit signal;

    If the determined number of constellation points is greater than a set threshold, determining to perform demodulation processing on the transmit signal by using a first demodulation manner, where the first demodulation manner includes minimum mean square error MMSE demodulation; or Determining, by using a second demodulation manner, demodulating the transmit signal, if the number of the determined constellation points is less than or equal to the threshold, where the second demodulation mode includes symbol level interference cancellation SLIC demodulation And maximum likelihood ML demodulation.
13. The apparatus according to claim 11 or 12, wherein, if SLIC demodulation is employed, the demodulation module performs demodulation processing on the equivalent transformed received signal, including:

    Determining, for each demodulation, the signal of each layer of the equivalent transmission signal according to the following formula a value and a variance; and determining a log likelihood ratio LLR value of each layer of the equivalent transmit signal in each demodulation based on the obtained mean and variance;

    

    

    Where E(x _j ) represents the mean of the j-th layer signal of the equivalent transmitted signal, Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal, and Pr(x _j ) represents E ( The prior probability of x _j ),

    

    {x _j } represents all possible values of the j-th layer signal of the equivalent transmission signal in the constellation corresponding to the equivalent transmission signal,

    

    a weighting vector representing the jth layer signal of the equivalent transmitted signal,

    

    The equivalent noise of the jth layer signal representing the equivalent transmitted signal, j ∈ {B+1, ..., L}, L represents the total number of layers of the received transmitted signal, and B represents the The total number of layers of the first transmitted signal.
14. The apparatus according to claim 11 or 12, wherein, if SLIC demodulation is employed, the demodulation module performs demodulation processing on the equivalent transformed received signal, including:

    Deriving constellation points in the constellation corresponding to the equivalent transmit signal into M groups according to positions of constellation points in the constellation corresponding to the equivalent transmit signal, to calculate LLR, mean and sum of each set of constellation points The LLR, the mean value and the variance of the constellation points in the constellation corresponding to the second transmitted signal can be multiplexed when the variance is performed;

    For each demodulation in the SLIC demodulation, the mean and variance of each set of constellation points are respectively calculated according to the LLR value of the last demodulation; and the calculated mean values of each set of constellation points are combined to obtain the second solution. The mean value of the modulation, the calculated variance of each set of constellation points is combined to obtain the variance of the demodulation; and the LLR value of the demodulation is calculated according to the mean and variance of the demodulation.
15. The apparatus according to claim 14, wherein said demodulation module combines the calculated mean values of each set of constellation points according to the following formula to obtain each layer of said equivalent transmitted signal in said SLIC solution Mean of the adjustment:

    

    Where E(x _j ) represents the mean value of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, and E(Ω _m ) and Pr(Ω _m ) respectively represent the mean value of the m-th constellation point and the first The prior probability corresponding to the mean value of the constellation points of the m group, M means that the constellation points in the constellation corresponding to the equivalent transmit signal are divided into M groups, j∈{B+1, . . . , L} L represents the total number of layers of the received transmitted signal, and B represents the total number of layers of the first transmitted signal.
16. The apparatus according to claim 14, wherein said demodulation module combines the calculated variances of each set of constellation points according to the following formula to obtain each layer of said equivalent transmitted signals at said SLIC Demodulation variance:

    

    Where Var(x _j ) represents the variance of the j-th layer signal of the equivalent transmitted signal in the SLIC demodulation, Var(Ω _m ) represents the variance of the m-th constellation point, and Pr(Ω _m ) represents the mth The prior probability corresponding to the mean value of the group constellation points, M means that the constellation points in the constellation diagram corresponding to the equivalent transmission signal are divided into M groups, j=B+1, ..., L, L The total number of layers of the received transmitted signal, B represents the total number of layers of the first transmitted signal.
17. The apparatus according to claim 11 or 12, wherein, if ML demodulation is employed, the demodulation module performs demodulation processing on the equivalent transformed received signal, including:

    And dividing a constellation point in the constellation corresponding to the equivalent transmit signal into M groups according to a position of a constellation point in the constellation corresponding to the equivalent transmit signal; and performing ML demodulation according to the second transmit signal The node selection method used, respectively, selects a set number of nodes from each set of constellation points; and selects each bit signal in each layer of the equivalent transmit signal from the selected nodes respectively a final node; and calculating an LLR value for each of the bit signals in each layer of the equivalent transmitted signal based on the selected final node.
18. The apparatus according to claim 17, wherein said demodulation module selects a final node for each bit signal in each layer of said equivalent transmitted signal from among the selected nodes, include:

    Selecting, from the selected nodes, a node that satisfies the set condition, and determining the selected node as the final node for each bit signal in each layer of the equivalent transmit signal;

    Where the setting condition is

    

    {x} denotes all possible points of the equivalent transmitted signal in its corresponding constellation diagram, b _j,i denotes the i-th bit signal of the j-th layer, and σ ² denotes the noise power,

    

    Representing a prior probability corresponding to the mean of the equivalent transmitted signals, y representing received data, H representing a channel matrix, x representing the second transmitted signal, j=B+1, ..., L, L Indicates the total number of layers of the transmitted signal, and B represents the total number of layers of the first transmitted signal.
19. The apparatus according to claim 18, wherein said demodulation module calculates an LLR value of each bit signal in each layer of said equivalent transmitted signal according to a selected final node according to the following formula:

    

    Where λ _j,i represents the LLR value of the i-th bit signal of the j-th layer of the equivalent transmitted signal.
20. The apparatus according to claim 14 or 17, wherein the demodulation module compares the position of the constellation point in the constellation corresponding to the equivalent transmission signal to the constellation corresponding to the equivalent transmission signal The constellation points are divided into M groups, including:

    And a constellation point in the constellation corresponding to the second transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle; or

    The constellation points in the constellation corresponding to the second transmit signal are divided into a group by constraining the constellation points by compressing the same compression amount; or

    In the constellation points in the constellation corresponding to the equivalent transmit signal, the constellation points in the constellation corresponding to the second transmit signal are divided into a group by rotating the same angle and compressing the same compression amount to obtain constellation points.

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