CN110620627B - A non-stationary channel modeling method and apparatus for a vehicle-to-vehicle multi-antenna system - Google Patents

Abstract

In order to solve the problems of the prior art, the present disclosure provides a non-stationary channel modeling method and device for a vehicle-to-vehicle multi-antenna system, which can establish a high-precision channel model. A non-stationary channel modeling method for a vehicle-to-vehicle multi-antenna system, comprising: establishing a double-loop model with a transmitter and a receiver as the center; establishing a semi-ellipsoid model with the transmitter and receiver as the focus; based on the double-loop model and the semi-ellipse The spherical model obtains the direct path, the single-shot path and the double-shot path; the channel impulse response function from the transmitter to the receiver is obtained based on the direct path, the single-shot path and the double-shot path; the spatiotemporal correlation function is obtained based on the channel impulse response function. The present disclosure establishes a channel model based on the direct path, the single-shot path and the dual-shot path, and the established model has higher accuracy and can better characterize the characteristics of the V2V MIMO channel.

Description

A non-stationary channel modeling method and device for a vehicle-to-vehicle multi-antenna system

technical field

The present disclosure relates to the field of communications, and in particular, to a non-stationary channel modeling method and device for a vehicle-to-vehicle multi-antenna system.

Background technique

In recent years, Massive MIMO (Multiple Input Multiple Output) multi-antenna wireless communication technology has become the focus of research due to its advantages of significantly improving spectral efficiency and system capacity. At the same time, vehicle-to-vehicle (V2V) communication is considered to be one of the indispensable parts of intelligence. Therefore, considering the adoption of the MIMO multi-antenna wireless communication technology in the V2V communication system (the V2V communication system employing the MIMO multi-antenna wireless communication technology is referred to as the vehicle-to-vehicle multi-antenna system for short), for the fifth generation wireless communication network (5G) is very helpful. Existing related literatures have given geometric modeling methods of MIMO channels in V2V scenarios, but the models established according to the existing modeling methods have low accuracy and cannot accurately characterize the characteristics of V2V MIMO channels.

SUMMARY OF THE INVENTION

In order to solve at least one of the above technical problems, the present disclosure provides a non-stationary channel modeling method and device for a vehicle-to-vehicle multi-antenna system, which improves the high precision of the channel model.

In one aspect of the present disclosure, a non-stationary channel modeling method for a vehicle-to-vehicle multi-antenna system includes:

A double-loop model is established with the transmitter and receiver as the center;

A semi-ellipsoid model is established with the transmitter and receiver as the focus;

Obtain direct path, single shot path and double shot path based on double ring model and semi-ellipsoid model;

Obtain the channel impulse response function from the transmitter to the receiver based on the direct path, the single-shot path and the dual-shot path;

The spatiotemporal correlation function is obtained based on the channel impulse response function.

Optionally, the visible gain of the single-shot path and the dual-shot path is calculated according to the Hata model path loss formula, and the single-shot path with the visible gain less than the threshold gain and the double-shot path with the visible gain less than the threshold gain are screened out.

Optionally, the channel impulse response function is:

表示直射路径分量；

表示单射路径分量，

表示双射路径分量；In the above formula,

represents the direct path component;

represents the injective path component,

represents the bijective path component;

in,

Optionally, let the number of scatterers in each ring region in the double-ring model and the number of scatterers in the region of the semi-ellipsoid model be S, and optimize the spatiotemporal correlation function.

Optionally, the obtaining the spatiotemporal correlation function based on the channel impulse response function includes:

Create a spatiotemporal function expression:

Among them, h _kl,pq (t) represents the channel impulse response from the antenna element of row k row l column at the transmitting end to the antenna element of row p row q column at the receiving end at time t, h _{k′l′,p′q′} (t ) represents the channel impulse response from the antenna element in column k' row l' at the transmitting end to the antenna element in column p' row q' at the receiving end at time t, τ represents the time delay, * represents the symbol of complex conjugate, E represents Find the mathematical expectation symbol;

Based on the space-time function expression and the channel impulse response function, the path components of the space-time expression are obtained:

Direct path component:

N ₁ injective path components:

N ₂ injective path components:

N ₃ injective path components:

Bijective path components:

Among them, N1 indicates that N1 moving scatterers are distributed on the ring with the transmitting end as the center, n1 indicates the serial number of the scatterers on the multipath passing ring, and N2 indicates that there are N2 moving scatterers distributed on the ring with the receiving end as the center , n2 represents the serial number of the scatterer on the multipath passing through the ring, N3 represents the N3 stationary scatterers distributed on the semi-ellipsoid with the two centers as the foci, n3 represents the serial number of the scatterer on the multipath passing through the semi-ellipsoid, let The number of scatterers in each ring region in the double-ring model and the number of scatterers in the half-ellipsoid model region is S.

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间直射路径分量的多普勒频移，

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间的直射路径分量的接收相位,

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的直射路径分量的多普勒频移，

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的直射路径分量的接收相位；P_i和P_DB是归一化功率相关系数，满足

是散射体n_i与发射端M_T之间的最大多普勒频移；

是散射体n_i与接收端M_R之间的最大多普勒频移；

为

在x-y平面的方位角；

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间非直射路径分量的多普勒频移；

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间的非直射路径分量的接收相位；i＝1,2,3；NLoS表示非视距分量；

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间的非直射双射路径分量的多普勒频移；

表示t时刻从发射端k行l列天线元素到接收端p行q列天线元素之间的非直射双射路径分量的接收相位，

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的非直射路径分量的多普勒频移；

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的非直射路径分量的接收相位；

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的非直射双射路径分量的多普勒频移；

表示t时刻从发射端k’行l’列天线元素到接收端p’行q’列天线元素之间的非直射双射路径分量的接收相位。In the above formula, K is the Rice factor; e is a constant, j is an imaginary number, t is a time variable,

Represents the Doppler frequency shift of the direct path component from the antenna element of row k row l column at the transmitting end to the antenna element of row p row q column at the receiving end at time t,

represents the receiving phase of the direct path component between the antenna elements of k rows and l columns of the transmitting end to the antenna elements of p rows and q columns of the receiving end at time t,

Represents the Doppler frequency shift of the direct path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t,

Represents the receiving phase of the direct path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t; P _i and P _DB are the normalized power correlation coefficients, satisfying

is the maximum Doppler frequency shift between the scatterer _ni and the transmitter _MT ;

is the maximum Doppler frequency shift between the scatterer _ni and the receiver _MR ;

for

Azimuth in the xy plane;

Represents the Doppler frequency shift of the indirect path component from the antenna element of row k row l column at the transmitting end to the antenna element of row p row q column at the receiving end at time t;

Represents the receiving phase of the indirect path component from the antenna element of row k row l column at the transmitting end to the antenna element p row q column at the receiving end at time t; i=1, 2, 3; NLoS represents the non-line-of-sight component;

Represents the Doppler frequency shift of the indirect dual-radio path component between the antenna elements of k rows and l columns of the transmitting end to the antenna elements of p rows and q columns of the receiving end at time t;

represents the receiving phase of the indirect dual-radiation path component between the antenna elements of k rows and l columns of the transmitting end to the antenna elements of p rows and q columns of the receiving end at time t,

Represents the Doppler frequency shift of the indirect path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t;

Represents the receiving phase of the indirect path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t;

Represents the Doppler frequency shift of the indirect dual-radio path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t;

Represents the receiving phase of the indirect dual-radiation path component from the antenna element of the transmitting end k' row l' column to the receiving end p' row q' column antenna element at time t.

Optionally, the method further includes predicting the performance of the communication system based on the spatiotemporal correlation function, or verifying the performance of the communication system based on the spatiotemporal correlation function, or performing back-end signal processing based on the spatiotemporal correlation function.

Another aspect of the present disclosure is a non-stationary channel modeling apparatus for a vehicle-to-vehicle multi-antenna system, comprising:

The double-loop model building module is used to establish a double-loop model with the transmitting end and the receiving end as the center of the circle;

The semi-ellipsoid model building module is used to build a semi-ellipsoid model with the transmitting end and the receiving end as the focus;

The path acquisition module is used to obtain direct paths, single-shot paths and bi-jective paths based on the double-ring model and the semi-ellipsoid model;

The channel impulse response function acquisition module is used to obtain the channel impulse response function from the transmitter to the receiver based on the direct path, the single-shot path and the dual-shot path;

The spatiotemporal correlation function obtaining module is used to obtain the spatiotemporal correlation function based on the channel impulse response function.

Optionally, the path acquisition module is further configured to calculate the visible gain of the single-shot path and the dual-shot path according to the Hata model path loss formula, and filter out the single-shot path with the visible gain less than the threshold gain and the double-shot path with the visible gain less than the threshold gain. shot path.

Optionally, the device further includes a spatiotemporal correlation function optimization module, configured to optimize the spatiotemporal correlation function by setting the number of scatterers in each ring region in the double-ring model and the number of scatterers in the semi-ellipsoid model region as S.

Optionally, the apparatus further includes a processing module configured to predict the performance of the communication system based on the spatiotemporal correlation function, or verify the performance of the communication system based on the spatiotemporal correlation function, or perform back-end signal processing based on the spatiotemporal correlation function.

The invention takes the transmitting end and the receiving end as the center of the circle to establish a double-ring model; takes the transmitting end and the receiving end as the focus to establish a semi-ellipsoid model; Path, single-shot path and dual-shot path establish channel models, and the established models have higher accuracy and can better characterize the characteristics of V2V MIMO channels.

Description of drawings

The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure, are included to provide a further understanding of the disclosure, and are incorporated in and constitute the present specification part of the manual.

FIG. 1 is a flowchart of a method in an exemplary embodiment of the present disclosure;

2 is a channel model diagram in an exemplary embodiment of the present disclosure;

FIG. 3 is a device connection diagram in an exemplary embodiment of the present disclosure.

Detailed ways

The present disclosure will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related content, but not to limit the present disclosure. In addition, it should be noted that, for the convenience of description, only the parts related to the present disclosure are shown in the drawings.

It should be noted that the embodiments of the present disclosure and the features of the embodiments may be combined with each other unless there is conflict. The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As shown in Figures 1 and 2, a non-stationary channel modeling method for a vehicle-to-vehicle multi-antenna system includes:

Step S1: establish a double-ring model with the transmitting end and the receiving end as the center;

Step S2: establishing a semi-ellipsoid model with the transmitting end and the receiving end as the focus;

Step S3: obtaining a direct path, a single shot path and a double shot path based on the double ring model and the semi-ellipsoid model;

Step S4: obtaining the channel impulse response function from the transmitter to the receiver based on the direct path, the single-shot path and the dual-shot path;

Step S5: obtaining a spatiotemporal correlation function based on the channel impulse response function.

In this embodiment, the transmitting end _MT and the receiving end _MR of the vehicle-to-vehicle multi-antenna system use uniform planar array antennas, and the non-stationary channel modeling method of the vehicle-to-vehicle multi-antenna system is to establish a channel from the transmitting end k rows and l columns to the receiving end. A method for channel modeling between antenna elements at end p rows and q columns.

As shown in Figure 2, in step S1, the double-ring model includes a first ring with the transmitting end as the center and a second ring with the receiving end as the center, the radius of the first ring is denoted as R _t , and the radius of the second ring Denoted as R _r , the semi-ellipsoid model takes the transmitting end and the receiving end as the two foci of the ellipse in the model, the long and short semi-axes of the ellipse are a and b respectively, and the focal distance is D ₀ .

的车辆(即第一散射体N₁′)；接收端移动速度向量记为v_R，以接收端为圆心的第二圆环上分布着N₂个移动速度向量为

的车辆(即第二散射体N₂′)；考虑车辆沿道路行驶，假设所有的速度方向均沿x轴正方向。假设半椭球模型(图2中的半椭球区域，)分布着N₃个静止散射体(即第三散射体N₂′)。本申请中，N′_i表示散射体本身，N_i表示散射体数量，n_i表示N′_i散射体集合中的单个散射体，取值为1到N_i。The moving speed vector of the transmitting end is denoted as v _T , and N ₁ moving speed vectors are distributed on the first ring with the transmitting end as the center of the circle, which is

The vehicle (that is, the first scatterer N ₁ ′); the moving speed vector of the receiving end is denoted as v _R , and there are N ₂ moving speed vectors distributed on the second ring with the receiving end as the center of the circle:

The vehicle (ie the second scatterer N ₂ ′); consider the vehicle traveling along the road, assuming that all the speed directions are along the positive direction of the x-axis. It is assumed that the semi-ellipsoid model (the semi-ellipsoid region in Fig. 2 ) is distributed with N ₃ stationary scatterers (ie, the third scatterer N ₂ '). In this application, N' _i represents the scatterer itself, _Ni represents the number of scatterers, _ni represents a single scatterer in the set of N' _i scatterers, and ranges from 1 to N _i .

The direct path in step S3 is the direct path from the transmitter to the receiver, the single shot path is the path from the transmitter to the receiver after passing through a scatterer (a first scatterer, a second scatterer or a third scatterer), and a double shot path. The path is the path to the receiving end after passing through two scatterers (a first scatterer and a second scatterer).

The technical solution of the present disclosure combines the direct path component (ie the line-of-sight component), the single-shot component of the stationary scatterer, the single-shot component of the moving scatterer, and the secondary scattering component of the moving scatterer to obtain the channel impulse response function and the space-time The correlation function makes the model more accurate and closer to the actual environment of vehicle communication.

The channel impulse response h _kl,pq (t) consists of a direct path component, a single-shot path component passing through N ₁ ', N ₂ ', N ₃ ', respectively, and a dual-shot path component passing through N ₁ 'N ₂ '.

Specifically expressed as:

表示直射路径分量；

表示单射路径分量，

表示双射路径分量。

represents the direct path component;

represents the injective path component,

represents a bijective path component.

表示时间变量t下发射端k行l列到接收端p行q列的直射路径分量；

表示时间变量t下发射端k行l列通过n_i到接收端p行q列的单射路径分量；

表示时间变量t下发射端k行l列通过n₁和n₂到接收端p行q列的双射路径分量。Specifically, the subscript k1 in the formula represents the k row and 1 column of the transmitter, pq represents the p row and q column of the receiver, and t represents the time variable;

Represents the direct path component from the transmitting end k row l column to the receiving end p row q column under the time variable t;

Represents the single-shot path component from the transmitting end k row l column to the receiving end p row q column through n _i under the time variable t;

Represents the bijective path components from the transmitter in row k, column l, through n ₁ and n ₂ to the receiver in row p, column q, under the time variable t.

in:

Direct path component:

表示直射路径的多普勒频移，

表示直射路径分量的接收相位。j表示虚数,平方等于-1,t表示时间变量。具体的，

表示时间变量t下发射端k行l列到接收端p行q列的直射路径分量的多普勒频移，

表示时间变量t下发射端k行l列到接收端p行q列的直射路径分量的接收相位。K is the Rice factor, e is a constant, and its value is about 2.71828,

represents the Doppler shift of the direct path,

Represents the receive phase of the direct path component. j represents the imaginary number, the square is equal to -1, and t represents the time variable. specific,

Represents the Doppler frequency shift of the direct path component from the transmitter in row k, column l to the receiver, in column p, row q, under the time variable t,

Represents the receiving phase of the direct path component from the transmitting end in row k, column l to the receiving end in row p, column q under the time variable t.

Single-shot path components:

是散射体n_i与M_T(M_R)之间的最大多普勒频移，即

表示散射体n_i与发射端M_T之间的最大多普勒频移，

表示散射体n_i与接收端M_R之间的最大多普勒频移；如图2所示，

为

在x-y平面的方位角，即

为

在x-y平面的方位角，

为

在x-y平面的方位角；

是时间变量t下发射端k行l列通过n_i到接收端p行q列的直射路径分量中的接收端M_R一侧的路径段，如i＝3时，

表示散射体n₃到接收端M_R段；

表示单射路径分量的接收相位，具体的，

表示时间变量t下发射端k行l列通过n_i到接收端p行q列的单射路径分量的接收相位。本申请中的公式参数均按上述方式命名。K is the Rice factor, _i =1,2,3, Pi is the normalized power correlation coefficient,

is the maximum Doppler shift between scatterer _ni and _{M T} (MR ), namely

represents the maximum Doppler frequency shift between the scatterer _ni and the transmitter _MT ,

represents the maximum Doppler frequency shift between the scatterer _ni and the receiver _MR ; as shown in Figure 2,

for

The azimuth in the xy plane, i.e.

for

Azimuth in the xy plane,

for

Azimuth in the xy plane;

is the path segment on the receiving end _MR side in the direct path component of the transmitting end k row l column passing through n _i to the receiving end p row q column under the time variable t, such as when i=3,

Represents the _MR segment from the scatterer n ₃ to the receiver;

represents the received phase of the single-shot path component, specifically,

Represents the receiving phase of the single-shot path component from the transmitting end in row k, column l through _ni to the receiving end in row q, column under the time variable t. The formula parameters in this application are named in the above-mentioned manner.

Bijective path components:

是散射体n₁与发射端M_T之间的最大多普勒频移，

是散射体n₂与接收端M_R之间的最大多普勒频移。

表示双射路径分量的接收相位；

为

在x-y平面的方位角，

为

在x-y平面的方位角,具体的，

表示时间变量t下发射端k行l列通过n₁和n₂到接收端p行q列的双射路径分量的接收相位；

是时间变量t下发射端k行l列通过n₁到接收端p行q列的直射路径分量中的发射端M_T一侧的路径段，即散射体n₁到发射端M_T段；

是时间变量t下发射端k行l列通过n₂到接收端p行q列的直射路径分量中的接收端M_R一侧的路径段，即散射体n₂到接收端M_R段。K is the Rice factor, P _i and P _DB are the normalized power correlation coefficients, satisfying

is the maximum Doppler shift between the scatterer _{n 1} and the transmitter MT,

is the maximum Doppler shift between the scatterer n ₂ and the receiver _MR .

represents the received phase of the bijection path component;

for

Azimuth in the xy plane,

for

The azimuth in the xy plane, specifically,

Represents the receiving phase of the bijection path component from the transmitting end k row l column through n ₁ and n ₂ to the receiving end p row q column under the time variable t;

is the path segment on the side of the transmitting end MT in the direct path component of the transmitting end k row l column passing _{n 1} to the receiving end p row q column under the time variable t, that is, the scatterer n ₁ to the transmitting end _MT segment;

is the path segment on the receiving end _MR side in the direct path component of the transmitting end k row l column passing n ₂ to the receiving end row q column under the time variable t, that is, the scatterer n ₂ to the receiving end _MR segment.

The Doppler shift of each path component can be expressed as:

是散射体n_i与M_T(M_R)之间的最大多普勒频移，即

是散射体n₁与M_T之间的最大多普勒频移，

是散射体n₁与M_R之间的最大多普勒频移，

是散射体n₂与M_R之间的最大多普勒频移，

是散射体n₂与T_R之间的最大多普勒频移，λ＝c/f_c，f_c是载波频率，c是光速。Among them, <> represents the inner product of the vector, that is, the dot product. |||| represents the modulo value. The definition of vector inner product is used here. The inner product of two vectors divided by the modulus value of the two vectors is equal to the cosine value of the angle between the two vectors.

is the maximum Doppler shift between scatterer _ni and _{M T} (MR ), namely

is the maximum Doppler shift between scatterer _{n 1} and MT,

is the maximum Doppler shift between scatterer n ₁ and _MR ,

is the maximum Doppler _shift between scatterer n and _MR ,

is the maximum Doppler shift between scatterer n ₂ and _TR , λ=c/f _c , f _c is the carrier frequency, and c is the speed of light.

The received phase of each path component can be expressed as:

为

在x-y平面的方位角。考虑到静止散射体N₃表征街道周围环境中的高楼建筑、树木等实物，建模时高度不可忽略。记

为

的仰角，

为

与x轴的空间夹角，则有：where the initial phase

for

Azimuth in the xy plane. Considering that the static scatterer N ₃ represents real objects such as tall buildings and trees in the surrounding environment of the street, the height cannot be ignored in modeling. remember

for

the elevation angle,

for

The space angle with the x-axis is:

Considering the non-stationary characteristics of the channel, the time delay is τ, and the time-varying parameters are updated as follows at time t+τ:

Considering the influence of distance and path loss factors based on large-scale loss, the visible area of scatterers is divided. According to the characteristics of the block environment corresponding to the proposed model, we select the path loss formula of the Hata model:

为与接收天线相关的系数，h_T、h_R分别为发射天线和接收天线的高度，对于中等大小的覆盖范围，

取值为：where dB is the unit,

are the coefficients related to the receiving antenna, h _T and h _R are the heights of the transmitting and receiving antennas, respectively. For medium-sized coverage,

The value is:

According to the scene characteristics of this model, h _T =h _R =0 is taken, and the calculation formula of the path loss of this model is obtained:

PL _Hata (d)[dB]=68.75+ _27.72logfc +44.9logd(19)

Disregarding the power loss at the scattering point, the general formula for calculating the visible gain of the single-shot path and the double-shot path is obtained:

If the visible gain is greater than or equal to the threshold gain, the effective single-shot path and the bi-jective path are retained; if the visible gain is less than the threshold gain, the invalid path is screened out, and the path component is not considered when calculating the spatiotemporal correlation function.

The spatiotemporal correlation function can describe the changes of the channel in time and space, and characterize the channel characteristics. The calculation expression is as follows:

表示在时刻为t、时延为τ的条件下，从发射端k′行l′列到接收端p′行q′列的信道冲激响应。Among them, * represents complex conjugate, E[] represents mean value; ρ _{k'l'p'q',klpq} (t,τ) represents that under the condition of time t and delay τ, from the transmitting end k' The correlation function between the channel from column l' to column p' of column q' at the receiving end and the channel from column k, column l of the transmitting end to the channel of column p, column q at the receiving end.

It represents the channel impulse response from the transmitting end k' row l' column to the receiving end p' row q' column under the condition of time t and time delay τ.

In traditional assumptions, the number of scatterers in the model tends to be infinite, and both the angle of departure (AoD) and the angle of arrival (AoA) are represented by continuously varying probability density distributions. Based on this assumption, each path component in the above formula is calculated as follows, where the direct path component (LoS path component):

N1 _' , _N2 ' injective path components:

N ₃ ' injective path components:

Bijective path components:

Considering that the number of scatterers in the actual scene should be limited, let N ₁ =N ₂ =N ₃ =S, and the integral form is adjusted to the following summation formula:

N ₁ injective path components:

N ₂ injective path components:

N ₃ injective path components:

Bijective path components:

The above formula parameters can refer to the explanation in the previous section;

Let the delay factor τ=0 and k′l′p′q′=klpq respectively, the space-time correlation function can be simplified to obtain the spatial correlation function (CCF) and the time correlation function (ACF) respectively.

After the spatiotemporal correlation function, the performance of the communication system can be predicted based on the spatiotemporal correlation function, the performance of the communication system can be verified based on the spatiotemporal correlation function, and the back-end signal processing can be performed based on the spatiotemporal correlation function.

In this embodiment, the combination of the double-ring model and the semi-ellipsoid model (semi-ellipsoid model) is used to explore the change of the channel under the combined action of the static scatterer and the moving scatterer, and a uniform plane array is used for the antenna to characterize the near-field effect of spherical waves. The visible scattering region is divided by different path losses, and the spatiotemporal correlation function is analyzed by changing the parameters. The final effect can be displayed by computer simulation.

Another aspect of this embodiment, as shown in FIG. 3 , is a non-stationary channel modeling apparatus for a vehicle-to-vehicle multi-antenna system, including:

The double-loop model establishment module 1 is used to establish a double-loop model with the transmitting end and the receiving end as the center of the circle;

The semi-ellipsoid model building module 2 is used to establish a semi-ellipsoid model with the transmitting end and the receiving end as the focus;

The path obtaining module 3 is used to obtain the direct path, the single-shot path and the double-shot path based on the double-ring model and the semi-ellipsoid model;

a channel impulse response function acquiring module 4, used for acquiring the channel impulse response function from the transmitter to the receiver based on the direct path, the single-shot path and the dual-shot path;

The spatiotemporal correlation function obtaining module 5 is used for obtaining the spatiotemporal correlation function based on the channel impulse response function.

Optionally, the path acquisition module is further configured to calculate the visible gain of the single-shot path and the dual-shot path according to the Hata model path loss formula, and filter out the single-shot path with the visible gain less than the threshold gain and the double-shot path with the visible gain less than the threshold gain. shot path.

Optionally, the device further includes a spatiotemporal correlation function optimization module, configured to optimize the spatiotemporal correlation function by setting the number of scatterers in each ring region in the double-ring model and the number of scatterers in the semi-ellipsoid model region as S.

Optionally, the apparatus further includes a processing module configured to predict the performance of the communication system based on the spatiotemporal correlation function, or verify the performance of the communication system based on the spatiotemporal correlation function, or perform back-end signal processing based on the spatiotemporal correlation function.

The device in this embodiment is used to implement the method in the above-mentioned embodiment, and the principle and effect thereof are the same as those in the method, and the description in this embodiment will not be repeated.

In this embodiment, for the vehicle communication scenario, a geometry-based 3D non-stationary V2V MIMO communication channel model is proposed. Based on the uniform planar array antenna configuration, the double loop and the semi-ellipsoid model (semi-ellipsoid) are used to comprehensively consider the environment. The distribution of stationary and moving scatterers, with a finite approximation of the number of scatterers. Combined with the direct path component (line-of-sight component), the single-shot component passing through the stationary scatterer, the single-shot component passing through the moving scatterer, and the secondary scattering component passing through the moving scatterer, the channel impulse response and spatiotemporal correlation function expressions are derived Based on the power attenuation degree of the transmission path, the visible area division algorithm of the scatterer is designed. Finally, the effects of different parameters on the channel correlation are analyzed by simulation. The results show that the proposed model can well characterize the characteristics of V2V MIMO channels.

In the description of this specification, references to the terms "one embodiment/mode", "some embodiments/modes", "example", "specific example", or "some examples", etc. are intended to be combined with the description of the embodiment/mode A particular feature, structure, material, or characteristic described by way of example or example is included in at least one embodiment/mode or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment/mode or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments/means or examples. Furthermore, those skilled in the art may combine and combine the different embodiments/modes or examples described in this specification and the features of the different embodiments/modes or examples without conflicting each other.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.

Those skilled in the art should understand that the above-mentioned embodiments are only for clearly illustrating the present disclosure, rather than limiting the scope of the present disclosure. For those skilled in the art, other changes or modifications may also be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims (4)

1. A method of modeling non-stationary channels of a vehicle-to-vehicle multi-antenna system, comprising:

establishing a double-ring model by taking the transmitting end and the receiving end as circle centers;

establishing a semi-ellipsoid model by taking a transmitting end and a receiving end as focuses;

obtaining a direct path, a single-shot path and a bishot path based on the double-ring model and the semi-ellipsoid model;

calculating the visible gains of the single-ray path and the double-ray path according to a Hata model path loss formula, and screening out the single-ray path and the double-ray path of which the visible gains are smaller than a threshold gain;

obtaining a channel impulse response function from a transmitting end to a receiving end based on a direct path, a single-ray path and a double-ray path;

obtaining a space-time correlation function based on a channel impulse response function;

wherein,

is that k rows and l columns at a transmitting end pass through a static scatterer n under a time variable t₃Transmitting end M in direct path component to receiving end p rows and q columns_TOr receiving end M_RThe path section on one side of the device,

is a direct path section from k rows and l columns of a transmitting end to p rows and q columns of a receiving end under a time variable t,

is composed of

The angle of elevation of (a) is,

is composed of

The spatial angle with the x-axis is,

is that

Azimuth in the x-y plane;

the obtaining the space-time correlation function based on the channel impulse response function comprises:

establishing a space-time function expression:

wherein h is_kl,pq(t) represents the channel impulse response between k rows and l columns of antenna elements at the transmitting end and p rows and q columns of antenna elements at the receiving end at time t, h_{k′l′,p′q′}(t) represents the channel impulse response from k 'row l' row antenna elements at the transmitting end to p 'row q' row antenna elements at the receiving end at the time t, wherein tau represents time delay, a symbol for solving conjugate complex number, and E represents the mathematical expectation symbol;

obtaining each path component of the space-time expression based on the space-time function expression and the channel impulse response function:

direct path component:

N₁single-shot path component:

N₂single-shot path component:

N₃single-shot path component:

bijective path component:

wherein N is₁Indicating that N is distributed on the ring with the transmitting end as the center₁A moving scatterer, n₁Number of scatterers on the ring representing multipath₂Indicating that N is distributed on the ring with the receiving end as the center₂A moving scatterer, n₂Number of scatterers on the ring representing multipath₃Showing that N is distributed on a semi-ellipsoid taking two circle centers as focuses₃A static scatterer, n₃Representing the serial number of scatterers on a semi-ellipsoid passed by multipath, and making the number of scatterers in each ring region and the number of scatterers in the semi-ellipsoid model region in a double-ring model be S;

the channel impulse response function is:

in the above formula, the first and second carbon atoms are,

representing the direct path component;

the components of the single-ray path are represented,

representing the bijective path component;

wherein,

in the above formula, K is the Rice factor; e is a constant, j represents an imaginary number, t represents a time variable,

indicating the doppler shift of the direct path component from k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

representing the reception phase of the direct path component between k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

represents the doppler shift of the direct path component between k ' rows/columns of antenna elements at time t from the transmitting end to p ' rows q ' columns of antenna elements at the receiving end,

representing the receiving phase of a direct path component between k 'rows and l' columns of antenna elements at the transmitting end to p 'rows and q' columns of antenna elements at the receiving end at the time t; p_iAnd P_DBIs a normalized power correlation coefficient satisfying

Is a scatterer n_iAnd a transmitting terminal M_TMaximum doppler shift in between;

is a scatterer n_iAnd receiving end M_RMaximum doppler shift in between;

is composed of

Azimuth in the x-y plane;

the Doppler frequency shift of a non-direct path component between k rows and l columns of antenna elements at a transmitting end and p rows and q columns of antenna elements at a receiving end at the moment t is represented;

the receiving phase of a non-direct path component between k rows and l columns of antenna elements at a transmitting end and p rows and q columns of antenna elements at a receiving end at the time t is represented; i is 1,2, 3; NLoS represents a non-line-of-sight component;

the Doppler frequency shift of a non-direct bijective path component between the k rows and l columns of antenna elements at the transmitting end and p rows and q columns of antenna elements at the receiving end at the time t is represented;

representing the reception phase of the non-direct bijective path component between k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

the Doppler frequency shift of a non-direct path component between k 'rows and l' columns of antenna elements at the transmitting end and p 'rows and q' columns of antenna elements at the receiving end at the time t is represented;

representing the receiving phase of a non-direct path component between k 'rows and l' columns of antenna elements at the transmitting end and p 'rows and q' columns of antenna elements at the receiving end at the time t;

the Doppler frequency shift of a non-direct bijective path component between k 'rows and l' columns of antenna elements at the transmitting end and p 'rows and q' columns of antenna elements at the receiving end at the time t is represented;

representing the receive phase of the non-direct bijection path component between k ' rows/columns of antenna elements at time t from the transmitting end to p ' rows q ' columns of antenna elements at the receiving end.

2. The method of claim 1, further comprising predicting communication system performance based on a spatio-temporal correlation function, or verifying communication system performance based on a spatio-temporal correlation function, or performing back-end signal processing based on a spatio-temporal correlation function.

3. A non-stationary channel modeling apparatus for a vehicle-to-vehicle multi-antenna system, comprising:

the double-ring model establishing module is used for establishing a double-ring model by taking the transmitting end and the receiving end as circle centers;

the semi-ellipsoid model establishing module is used for establishing a semi-ellipsoid model by taking the transmitting end and the receiving end as focuses;

the path acquisition module is used for acquiring a direct path, a single-shot path and a bishot path based on the double-ring model and the semi-ellipsoid model; calculating the visible gains of the single-ray path and the double-ray path according to a Hata model path loss formula, and screening out the single-ray path and the double-ray path of which the visible gains are smaller than a threshold gain;

the channel impulse response function acquisition module is used for acquiring a channel impulse response function from a transmitting end to a receiving end based on a direct path, a single-shot path and a double-shot path;

wherein,

is that k rows and l columns at a transmitting end pass through a static scatterer n under a time variable t₃Transmitting end M in direct path component to receiving end p rows and q columns_TOr receiving end M_RThe path section on one side of the device,

is a direct path section from k rows and l columns of a transmitting end to p rows and q columns of a receiving end under a time variable t,

is composed of

The angle of elevation of (a) is,

is composed of

The spatial angle with the x-axis is,

is that

Azimuth in the x-y plane;

a spatio-temporal correlation function acquisition module for

Establishing a space-time function expression:

wherein h is_kl,pq(t) represents the channel impulse response between k rows and l columns of antenna elements at the transmitting end and p rows and q columns of antenna elements at the receiving end at time t, h_{k′l′,p′q′}(t) represents the channel impulse response from k 'row l' row antenna elements at the transmitting end to p 'row q' row antenna elements at the receiving end at the time t, wherein tau represents time delay, a symbol for solving conjugate complex number, and E represents the mathematical expectation symbol;

obtaining each path component of the space-time expression based on the space-time function expression and the channel impulse response function:

direct path component:

N₁single-shot path component:

N₂single-shot path component:

N₃single-shot path component:

bijective path component:

wherein N is₁Indicating that N is distributed on the ring with the transmitting end as the center₁A moving scatterer, n₁Number of scatterers on the ring representing multipath₂Indicating that N is distributed on the ring with the receiving end as the center₂A moving scatterer, n₂Number of scatterers on the ring representing multipath₃Showing that N is distributed on a semi-ellipsoid taking two circle centers as focuses₃A static scatterer, n₃Representing the serial number of scatterers on a semi-ellipsoid passed by multipath, and making the number of scatterers in each ring region and the number of scatterers in the semi-ellipsoid model region in a double-ring model be S;

the channel impulse response function is:

in the above formula, the first and second carbon atoms are,

representing the direct path component;

the components of the single-ray path are represented,

representing the bijective path component;

wherein,

in the above formula, K is the Rice factor; e is a constant, j represents an imaginary number, t represents a time variable,

indicating the doppler shift of the direct path component from k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

representing the reception phase of the direct path component between k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

represents the doppler shift of the direct path component between k ' rows/columns of antenna elements at time t from the transmitting end to p ' rows q ' columns of antenna elements at the receiving end,

representing the receiving phase of a direct path component between k 'rows and l' columns of antenna elements at the transmitting end to p 'rows and q' columns of antenna elements at the receiving end at the time t; p_iAnd P_DBIs a normalized power correlation coefficient satisfying

Is a scatterer n_iAnd a transmitting terminal M_TMaximum doppler shift in between;

is a scatterer n_iAnd receiving end M_RMaximum doppler shift in between;

is composed of

Azimuth in the x-y plane;

the Doppler frequency shift of a non-direct path component between k rows and l columns of antenna elements at a transmitting end and p rows and q columns of antenna elements at a receiving end at the moment t is represented;

the receiving phase of a non-direct path component between k rows and l columns of antenna elements at a transmitting end and p rows and q columns of antenna elements at a receiving end at the time t is represented; i is 1,2, 3; NLoS represents a non-line-of-sight component;

the Doppler frequency shift of a non-direct bijective path component between the k rows and l columns of antenna elements at the transmitting end and p rows and q columns of antenna elements at the receiving end at the time t is represented;

representing the reception phase of the non-direct bijective path component between k rows and l columns of antenna elements at the transmitting end to p rows and q columns of antenna elements at the receiving end at time t,

indicating that at time t, the antenna elements are k 'row/column' from the transmitting end to p 'row q' from the receiving end' Doppler shift of the non-direct path component between the column antenna elements;

representing the receiving phase of a non-direct path component between k 'rows and l' columns of antenna elements at the transmitting end and p 'rows and q' columns of antenna elements at the receiving end at the time t;

the Doppler frequency shift of a non-direct bijective path component between k 'rows and l' columns of antenna elements at the transmitting end and p 'rows and q' columns of antenna elements at the receiving end at the time t is represented;

representing the receive phase of the non-direct bijection path component between k ' rows/columns of antenna elements at time t from the transmitting end to p ' rows q ' columns of antenna elements at the receiving end.

4. The apparatus of claim 3, wherein the apparatus further comprises a processing module for predicting communication system performance based on a spatiotemporal correlation function, or verifying communication system performance based on a spatiotemporal correlation function, or performing back-end signal processing based on a spatiotemporal correlation function.

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