CN105356922A - Nonuniform segmentation-based vertical-dimension codebook design method under 3D MIMO channel - Google Patents

Abstract

The invention relates to a nonuniform segmentation-based vertical-dimension codebook design method under a 3D MIMO channel, and belongs to the technical field of wireless communication. In the method, first a base station uses a uniform planar array antenna to generate a large-scale 3D-MIMO channel; then G full-rank DFT unitary matrixes are generated according to a rotary DFT formula to form a horizontal-dimension codebook F(h); then vertical-dimension wave beam downward inclination angle probability distribution is calculated with information of base station height, cell radius and the like, a plurality of discrete wave beam angles are obtained based on nonuniform segmentation, corresponding codeword vectors are generated, and a vertical-dimension codebook F(v) is built; and finally the horizontal-dimension codebook and the vertical-dimension codebook are combined, a Kronecker product is utilized to build a 3D-MIMO-oriented precoding codebook. The nonuniform segmentation-based codebook scheme proposed by the invention can obtain relatively strong precoding gain and interference rejection capability, thereby improving overall performance of a system.

Description

Based on the vertical dimension codebook design method of non-uniformly distributed load under 3D mimo channel

Technical field

The invention belongs to wireless communication technology field, relate to the vertical dimension codebook design method based on non-uniformly distributed load under a kind of 3DMIMO channel.

Background technology

In recent years, along with extensively popularizing of the intelligent terminal such as mobile phone, flat board, mobile data services amount presents explosive growth, and existing wireless communication system can not meet so huge business demand gradually.Therefore, academia and industrial circle expand in succession for the 5th third-generation mobile communication technology (5 ^thgeneration, 5G) research.And extensive MIMO (MultipleInputMultipleOutput, MIMO) technology is as one of the candidate key technology of 5G, compare existing forth generation mobile communication technology (4 ^thgeneration, 4G) technology, because it can promote spectrum efficiency and the energy efficiency of communication system very significantly, become the focus of research both at home and abroad at present.

Compare traditional MIMO, the sharply increase of extensive mimo antenna number, make base station obtain more accurate beam steering ability, inhibit the interference that wireless communication system brings simultaneously, can provide in huge community and the AF panel gain of Cell Edge User.But increase rapidly along with number of antennas increases the actual antennas array area brought, this brings severe challenge to the installation of Cell Site Placement and aerial array.At present, launch and the extensive 3D-MIMO (ThreeDimensional-MultipleInputMultipleOutput of formation based on the multiple antenna structure such as planar array, circular array and cube, 3D-MIMO), not only reduce aerial array to take up room, and the vertical dimension degree of freedom additionally brought makes it carry out interference coordination and AF panel more neatly, thus make whole system performance boost.

The large-scale and multiple users MIMO (MultiuserMIMO, MU-MIMO) that extensive MIMO technology and multi-user's combined together are formed, can utilize the spatial degrees of freedom throughput of elevator system and spectrum efficiency significantly further.And precoding is the key technology of MU-MIMO system, strategy is launched in exploitable channel state information (ChannelStateInformation, CSI) adjustment, thus effectively suppresses multi-user interference and improve received signal to noise ratio.Dirty paper code (DirtyPaperCoding, DPC) proves, if transmitting terminal can know interference signal accurately, then passes through certain precoding processing at transmitting terminal, the channel capacity of EVAC (Evacuation Network Computer Model) can be made identical with the channel capacity of Non-Interference System.Because DPC theory is difficult to be applied in practical MIMO system, some suboptimum precoding techniques arise at the historic moment.One class is the precoding technique based on Real-time Channel process, and as channel reversion, block of channels diagonalization etc., need transmitting terminal to know channel condition information completely.But number of antennas is huge in extensive mimo system, if transmitting terminal goes for complete CSI, feedback cost is too large and cannot realize.Another kind of is precoding technique based on code book, base station end and user side coexist an identical code book, and user side selects an optimum code word according to CSI, and its index is fed back to base station, base station end recovers optimum code word by codewords indexes, and carries out precoding processing.Owing to only having fed back optimum code word indexing, thus reduce feedback quantity significantly, be used widely at mimo system.The codebook construction of the existing precoding technique based on code book has the unitary matrice code book based on DFT, according to the Jim Glassman code book that Jim Glassman space packing principle is formed, and Householder code book etc.Unitary matrice code book is better performances under strong correlation channel, but codebook size is limited; Jim Glassman code book suppresses the scarce capacity of interference; Householder code book performance under correlated channels need to improve.But these code books all do not make full use of extensive 3D-MIMO channel characteristic, better can not mate extensive 3D-MIMO channel, so under extensive 3D-MIMO channel, precoding codebook needs to be optimized design.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of 3DMIMO (ThreeDimensional-MultipleInputMultipleOutput, 3D-MIMO) under channel based on the vertical dimension codebook design method of non-uniformly distributed load, in the method, first, base station adopts uniform planar array antenna to generate extensive 3D-MIMO channel; Then generate G full rank DFT unitary matrice according to rotation DFT formula and form horizontal dimension code book F ^(h); Then calculate vertical dimension downwards bevel beam angle probability distribution by information such as base station height and radius of societies, and then obtain some discrete beam angles based on non-uniformly distributed load, and generate corresponding codeword vector, construct vertical dimension code book F ^(v); Last combined level dimension code book and vertical dimension code book, and utilize Kronecker to amass the precoding codebook of structural plane to 3D-MIMO.

For achieving the above object, the invention provides following technical scheme:

Based on a vertical dimension codebook design method for non-uniformly distributed load under 3DMIMO channel, comprise the following steps:

Step one: based on non-uniformly distributed load structure vertical dimension code book F ^(v);

Step 2: tectonic level dimension code book F ^(h), adopt discrete Fourier transform (DiscreteFourierTransform, DFT) code book, and then utilize Kronecker to amass the precoding codebook F of computing structural plane to 3D-MIMO channel ^3D.

Further, described step one specifically comprises:

1) downwards bevel beam angle Cumulative Distribution Function is solved:

Consider that user is uniformly distributed in the orthohexagonal community that radius is r, highly for the base station of h is positioned at center of housing estate, in community, in unit are, the probability of user distribution is the Cumulative Distribution Function of angle of declination θ is as follows:

$F\left(\mathrm{\θ}\right)=\left\{\begin{array}{cc}1-Ap+B,& \mathrm{\θ}\∈\[{\mathrm{\θ}}_{\min },{\mathrm{\θ}}_o\]\\ 1-\frac{{\mathrm{\βh}}^2}{r^2\·{\tan }^2\left(\mathrm{\θ}\right)}& \mathrm{\θ}\∈\[{\mathrm{\θ}}_o,\mathrm{\π}/2\]\end{array}\right.$

Wherein ${\mathrm{\θ}}_{\min }=arctan\left(\frac{h}{r}\right)$ Represent minimum angle of declination, $\begin{array}{cc}{\mathrm{\θ}}_o=arctan\left(\frac{2h}{\sqrt{3}r}\right),& \mathrm{\β}=\frac{2\mathrm{\π}}{3\sqrt{3}},\end{array}$ $\begin{array}{cc}A=\frac{{\mathrm{\πh}}^2}{{\tan }^2\left(\mathrm{\θ}\right)}-6\arctan \left(\sqrt{\frac{4h^2}{3r^2{\tan }^2\left(\mathrm{\θ}\right)}-1}\right),& B=\sqrt{\frac{4h^2}{r^2{\tan }^2\left(\mathrm{\θ}\right)}-3};\end{array}$

2) non-uniformly distributed load patten's design discrete wave beam angle:

Downwards bevel beam angle θ is between interval [θ _min, θ _o) and [θ _o, pi/2), present the feature of non-uniform Distribution, the discrete wave beam angle that magnitude setting does not wait on two intervals is respectively to point to different beam directions, and concrete method to set up is as follows simultaneously:

At interval [θ _min, θ _o) upper evenly setting individual discrete wave beam angle, and at interval [θ _o, pi/2) on utilize Cumulative Distribution Function F (θ) to arrange in the mode of non-uniformly distributed load individual discrete wave beam angle, wherein α=F (θ _o) represent that beam angle θ is at interval [θ _min, θ _o) on probability, represent and get the integer being more than or equal to x; Discrete wave beam angle θ _ncan be calculated as follows:

${\mathrm{\θ}}_n=\left\{\begin{array}{cc}{\mathrm{\θ}}_{\min }+\frac{2n-1}{2N_1}({\mathrm{\θ}}_o-{\mathrm{\θ}}_{\min }),& n=1,2,\mathrm{...},N_1\\ \arctan \left(\frac{h}{r}\sqrt{\frac{\mathrm{\β}}{1-g\left(n\right)}}\right),& n=N_1+1,\mathrm{...},N\end{array}\right.$

Wherein $g\left(n\right)=\mathrm{\α}+\frac{1}{2N_2}\[2(n-N_1)-1\];$

3) according to the correlation structure steering vector between discrete wave beam angle and vertical dimension antenna:

The strong correlation between vertical dimension antenna is utilized to generate steering vector as follows:

$f_n^v=1/\sqrt{N_v}.{\left[\begin{array}{cccc}1& e^{-{\mathrm{j\β}}_n}& \mathrm{...}& e^{-j(N_v-1){\mathrm{\β}}_n}\end{array}\right]}^T$

Wherein represent the phase difference that the wave beam of different directions causes due to vertical dimensions antenna distance, N _vrepresent the vertical dimension antenna number of base station UPA, () ^tthe transposition of representing matrix.

Further, described step 2 specifically comprises:

Horizontal dimension code book F ^(h)generated by rotation DFT, (n, m) the individual element wherein in g sub-codebook is calculated as follows:

$F_g^{\left(h\right)}(n,m)=1/\sqrt{N_h}.\exp \left(j2\mathrm{\π}\frac{n}{N_h}\right(m+g/G\left)\right)$

Wherein n=1 .., N _h; M=1 ..., N _h; G=1 ..., G, N _hfor horizontal dimension antenna number, G represents the sub-codebook number of horizontal dimension; Combined level dimension code book and vertical dimension code book, utilizes Kronecker to amass the precoding codebook of computing structural plane to 3D-MIMO, and q sub-codebook in the precoding codebook of wherein 3D-MIMO is calculated as follows:

$F_q^{3D}=F_g^{\left(h\right)}\⊗f_n^v,$

Wherein n=1 .., N; G=1 ..., G; Q=gn, easily knows F ^3Din include G × N number of sub-codebook.

Beneficial effect of the present invention is: the channel information that the method for the invention not only combines horizontal dimensions and vertical dimensions carries out codebook design, and for vertical dimension channel characteristic with the structure vertical dimension code book of non-uniformly distributed load space manner, make vertical dimension wave beam distinguish user more exactly, and then improve the rejection ability of 3D code book to interference.So the code book scheme based on non-uniformly distributed load that the present invention proposes can obtain stronger pre-coding gain and interference rejection capability, improve the overall performance of system.

Accompanying drawing explanation

In order to make object of the present invention, technical scheme and beneficial effect clearly, the invention provides following accompanying drawing and being described:

Fig. 1 is the extensive 3D-MIMO channel model schematic diagram based on UPA configuration;

Fig. 2 is the codebook construction flow chart towards 3D-MIMO of the present invention;

Fig. 3 is the pre-coding system block diagram towards extensive 3D-MIMO;

Fig. 4 is the implementation and operation flow chart of 3D-MIMO system precoding code book.

Embodiment

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

Fig. 1 is the extensive 3D-MIMO channel model schematic diagram based on UPA configuration:

As shown in Fig. 1 (a), user is uniformly distributed in the orthohexagonal community that radius is r, and highly for the base station of h is positioned at center of housing estate position.As shown in Fig. 1 (b), base station end is configured to N _h× N _vtwo-dimentional UPA, horizontal dimension and vertical dimension antenna distance are d _hand d _v.The signal sent by base station end planar array arrives user side through scattering by L paths, then the channel matrix of user k is:

Wherein for the random phase of the l paths of user k, be uniformly distributed in interval [0,2 π], with represent the phase difference caused by vertical dimension and horizontal dimension antenna distance respectively, $a\left(u_{k,l}\right)={\[1,e^{-{\mathrm{ju}}_{k,l}},\mathrm{...},e^{-j(N_v-1)u_{k,l}}\]}^T$ With $b\left(v_{k,l}\right)={\[1,e^{-{\mathrm{jv}}_{k,l}},\mathrm{...},e^{-j(N_h-1)v_{k,l}}\]}^T$ Represent the direction vector by vertical dimension and horizontal dimension respectively, for base station is to the vertical angle of declination leaving angle of the l paths of user k, for base station is to the horizontal azimuth leaving angle of the l paths of user k, L such as to represent at the NLOS number of path of gain.

Fig. 2 is the codebook construction flow chart towards 3D-MIMO of the present invention, and specific implementation step is as follows:

Step 21:3D-MIMO channel parameter configures, and comprises radius of society r, the horizontal dimension antenna number N of base station height h, base station UPA _hwith vertical dimension antenna number N _v, and horizontal dimension and vertical dimension antenna distance d _hand d _v.

Step 22: structure vertical dimension code book, specific implementation process is as follows:

1) downwards bevel beam angle probability distribution is determined.According to the information such as height h and radius of society r of base station, then beam angle Cumulative Distribution Function can be calculated as follows:

$F\left(\mathrm{\θ}\right)=\left\{\begin{array}{cc}1-AP+B,& \mathrm{\θ}\∈\[{\mathrm{\θ}}_{\min },{\mathrm{\θ}}_o)\\ 1-\frac{{\mathrm{\βh}}^2}{r^2\·{\tan }^2\left(\mathrm{\θ}\right)},& \mathrm{\θ}\∈\[{\mathrm{\θ}}_o,\mathrm{\π}/2)\end{array}\right.$

Wherein $\begin{array}{ccc}{\mathrm{\θ}}_{\min }=\arctan \left(\frac{h}{r}\right),& {\mathrm{\θ}}_o=\arctan \left(\frac{2h}{\sqrt{3}r}\right),& A=\frac{{\mathrm{\πh}}^2}{{\tan }^2\left(\mathrm{\θ}\right)}-6\arctan \left(\sqrt{\frac{4h^2}{3r^2{\tan }^2\left(\mathrm{\θ}\right)}-1}\right),\end{array}$ $\begin{array}{ccc}B=\sqrt{\frac{4h^2}{r^2{\tan }^2\left(\mathrm{\θ}\right)}-3},& \mathrm{\β}=\frac{2\mathrm{\π}}{3\sqrt{3}},& p=\frac{2}{3\sqrt{3}\·r^2}\end{array}.$

2) non-uniformly distributed load beam angle is interval, determines the set of discrete wave beam angle.Through deriving, the n-th discrete angular can be calculated as follows

${\mathrm{\θ}}_n=\left\{\begin{array}{cc}{\mathrm{\θ}}_{\min }+\frac{2n+1}{2N_1}({\mathrm{\θ}}_o-{\mathrm{\θ}}_{\min }),& n=1,2,\mathrm{..},N_1\\ \arctan \left(\frac{h}{r}\sqrt{\frac{\mathrm{\β}}{1-g\left(n\right)}}\right),& n=N_1+1,\mathrm{....},N\end{array}\right.$

Wherein $g\left(n\right)=\mathrm{\α}+\frac{1}{2N_2}\[2(n-N_1)-1\],$ N represents vertical dimension codebook size, α=F (θ _o) represent that beam angle θ is at interval [θ _min, θ _o) on probability, represent and get the integer being more than or equal to x.

3) according to the correlation structure steering vector between discrete wave beam angle and vertical dimension antenna.Incide on aerial array because incident wave can be approximately parallel after Far Field Scattering volume scattering, therefore utilize the strong correlation between vertical dimension antenna to generate steering vector

$f_n^v=1/\sqrt{N_v}.{\left[\begin{array}{cccc}1& e^{-{\mathrm{j\β}}_n}& \mathrm{...}& e^{-j(N_v-1){\mathrm{\β}}_n}\end{array}\right]}^T,n=1,2,\mathrm{...},N$

Wherein represent the phase difference that different directions wave beam causes due to vertical dimensions antenna distance, N _vrepresent the vertical dimension antenna number of base station UPA, () ^tthe transposition of representing matrix.

Step 23: tectonic level dimension code book.Generate G full rank DFT matrix according to rotation DFT formula and form horizontal dimension code book F ^(h), (n, m) the individual element in g sub-codebook can be calculated as follows

$F_g^{\left(h\right)}(n,m)=1/\sqrt{N_h}.\exp \left(j2\mathrm{\π}\frac{n}{N_h}\right(m+g/G\left)\right),n=1,\mathrm{..},N_h;m=1,\mathrm{...},N_h;g=1,\mathrm{...},G$

Wherein N _hfor the horizontal dimension antenna number of base station UPA, G represents the number of sub-codebook.G sub-codebook can specifically be constructed as follows

$F_g^{\left(h\right)}=\frac{1}{\sqrt{N_h}}\left[\begin{array}{cccc}{e}^{j2\mathrm{\π}g1\frac{1+g/G}{N_h}}& e^{j2\mathrm{\π}g1\frac{2+g/G}{N_h}}& L& e^{j2\mathrm{\π}g1\frac{N_h+g/G}{N_h}}\\ e^{j2\mathrm{\π}g2\frac{1+g/G}{N_h}}& e^{j2\mathrm{\π}g2\frac{2+g/G}{N_h}}& L& e^{j2\mathrm{\π}g2\frac{N_h+g/G}{N_h}}\\ e^{j2\mathrm{\π}g3\frac{1+g/G}{N_h}}& e^{j2\mathrm{\π}g3\frac{2+g/G}{N_h}}& L& e^{j2\mathrm{\π}g3\frac{N_h+g/G}{N_h}}\\ M& M& O& M\\ e^{j2{\mathrm{\πgN}}_h\frac{1+g/G}{N_h}}& e^{j2{\mathrm{\πgN}}_h\frac{2+g/G}{N_h}}& L& e^{j2{\mathrm{\πgN}}_h\frac{N_h+g/G}{N_h}}\end{array}\right]$

Step 24: structure 3D precoding codebook.Combined level dimension code book and vertical dimension code book, and utilize Kronecker long-pending structure 3D code book.Q sub-codebook in 3D code book can be calculated as follows

$F_q^{3D}=F_g^{\left(h\right)}\⊗f_n^v$

Wherein n=1 .., N; G=1 ..., G; Q=gn.Easily know F ^3Din include G × N number of sub-codebook.By 3D code book F ^3Ddeposit in base station end and user side, for the precoding processing of data flow.

Fig. 3 is the pre-coding system block diagram towards extensive 3D-MIMO, is described in detail as follows:

Base station end is configured to N _t=N _h× N _vtwo-dimentional UPA, wherein N _trepresent the total number of transmit antennas in base station, N _hrepresent horizontal dimension antenna number, N _vrepresent vertical dimension antenna number, require that each transmit antennas all can information simultaneously in processing horizontal dimension and vertical dimensions, receiving terminal has K user, and each user's reception antenna number is 1.

For simplifying the analysis, suppose that channel is flat fading channel, then the signal that a kth user receives is

$y_k=H_k{T}_k{s}_k+\underset{i=1,i\≠k}{\overset{K}{\Σ}}{H}_k{T}_i{s}_i+n_k$

Wherein H _kt _ks _krepresent the desired signal of a kth user, represent the interference from other subscriber signals that a kth user receives, H _kand T _krepresent channel matrix and the pre-coding matrix of user k respectively, s _krepresent that base station sends to the data flow of user k, suppose that base station sends data to each user's constant power, namely meet p represents the total transmitting power of base station end.N _krepresent and obey CN (0, σ ²) white Gauss noise of probability distribution.

In extensive 3D-MIMO system, base station and user store 3D code book simultaneously.First user estimates 3D channel matrix H based on public guide frequency _kand select optimum pre-encoding codeword in the codebook according to codeword selection criterion, then by call number corresponding with it and other feedback of channel information to base station, base station recovers optimum code word according to the feedback information of the user received, and precoding processing is carried out to user data, finally the data after precoding are launched through antenna for base station.

Fig. 4 is the implementation and operation flow chart of 3D-MIMO system precoding code book, and specific implementation step is as follows:

Step 41: channel parameter configures.User is uniformly distributed in the regular hexagon cell area that radius is r, and base station is positioned at center of housing estate, is highly h.Base station end is configured to N _h× N _vtwo-dimentional UPA, wherein N _hrepresent the horizontal dimension antenna number of base station UPA, N _vrepresent the vertical dimension antenna number of base station UPA, user side reception antenna number is 1.

Step 42: by the 3D precoding codebook according to extensive 3D-MIMO channel model design, deposits in base station end and each user side.

Step 43: user obtains 3D channel information H based on public guide frequency information by channel estimating _k, from 3D code book, select optimum pre-encoding codeword based on maximization signal-to-noise ratio (SNR) Criterion, and call number PMI corresponding with it fed back to base station end.

Suppose that the optimum codeword vector that user k selects is then the SINR of user k is

${\mathrm{SINR}}_k=\frac{\left|\right|H_k{w}_p^q|{|}^2}{\underset{j=1,j\≠p}{\overset{K}{\Σ}}\left|\right|H_k{w}_j^q|{|}^2+{\mathrm{\σ}}^2}$

Wherein be p codeword vector of q sub-codebook.By maximum SINR, optimum code word indexing can be selected from codebook set wherein represent optimum sub-codebook index, its 1,2 ..., value in G × N}, represent the optimum code word indexing in individual sub-codebook, its 1,2 ..., M} value.Corresponding computing formula is as follows

$\[q_k^{opt},p_k^{opt}\]=\arg \underset{q,p}{\max }{\mathrm{SINR}}_k$

Will with respectively as the optimum precoding sub-codebook index of user k and corresponding optimum code word indexing with it utilize Limited Feedback passage, by each self-corresponding optimum sub-codebook index PIM ¹and PIM with it ²feed back to base station.

Step 44: base station end is according to the PIM received ¹and PIM ²recover the optimum pre-encoding codeword that each user is corresponding with it, thus realize that data are sent to each user and carry out precoding processing.

What finally illustrate is, above preferred embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although by above preferred embodiment to invention has been detailed description, but those skilled in the art are to be understood that, various change can be made to it in the form and details, and not depart from claims of the present invention limited range.

Claims (3)

1. under 3DMIMO channel based on a vertical dimension codebook design method for non-uniformly distributed load, it is characterized in that: comprise the following steps:

Step one: based on non-uniformly distributed load structure vertical dimension code book F ^(v);

Step 2: tectonic level dimension code book F ^(h), adopt discrete Fourier transform (DiscreteFourierTransform, DFT) code book, and then utilize Kronecker to amass the precoding codebook F of computing structural plane to 3D-MIMO channel ^3D.

2. under a kind of 3DMIMO channel according to claim 1 based on the vertical dimension codebook design method of non-uniformly distributed load, it is characterized in that: described step one specifically comprises:

1) downwards bevel beam angle Cumulative Distribution Function is solved:

Consider that user is uniformly distributed in the orthohexagonal community that radius is r, highly for the base station of h is positioned at center of housing estate, in community, in unit are, the probability of user distribution is the Cumulative Distribution Function of angle of declination θ is as follows:

$F\left(\mathrm{\θ}\right)=\left\{\begin{array}{cc}1-Ap+B,& \mathrm{\θ}\∈\[{\mathrm{\θ}}_{\min },{\mathrm{\θ}}_o)\\ 1-\frac{{\mathrm{\βh}}^2}{r^2\·{\tan }^2\left(\mathrm{\θ}\right)},& \mathrm{\θ}\∈\[{\mathrm{\θ}}_o,\mathrm{\π}/2)\end{array}\right.$

Wherein ${\mathrm{\θ}}_{\min }=\arctan \left(\frac{h}{r}\right)$ Represent minimum angle of declination, ${\mathrm{\θ}}_o=arctan\left(\frac{2h}{\sqrt{3}r}\right),\mathrm{\β}=\frac{2\mathrm{\π}}{3\sqrt{3}},$ $A=\frac{{\mathrm{\πh}}^2}{{\tan }^2\left(\mathrm{\θ}\right)}-6arctan\left(\sqrt{\frac{4h^2}{3r^2{\tan }^2\left(\mathrm{\θ}\right)}-1}\right),B=\sqrt{\frac{4h^2}{r^2{\tan }^2\left(\mathrm{\θ}\right)}-3};$

2) non-uniformly distributed load patten's design discrete wave beam angle:

Downwards bevel beam angle θ is between interval [θ _min, θ _o) and [θ _o, pi/2), present the feature of non-uniform Distribution, the discrete wave beam angle that magnitude setting does not wait on two intervals is respectively to point to different beam directions, and concrete method to set up is as follows simultaneously:

At interval [θ _min, θ _o) upper evenly setting individual discrete wave beam angle, and at interval [θ _o, pi/2) on utilize Cumulative Distribution Function F (θ) to arrange in the mode of non-uniformly distributed load individual discrete wave beam angle, wherein α=F (θ _o) represent that beam angle θ is at interval [θ _min, θ _o) on probability, represent and get the integer being more than or equal to x; Discrete wave beam angle θ _ncan be calculated as follows:

${\mathrm{\θ}}_n=\left\{\begin{array}{cc}{\mathrm{\θ}}_{\min }+\frac{2n-1}{2N_1}\left({\mathrm{\θ}}_o-{\mathrm{\θ}}_{\min }\right),& n=1,2,\mathrm{..},N_1\\ \arctan \left(\frac{h}{r}\sqrt{\frac{\mathrm{\β}}{1-g\left(n\right)}}\right),& n=N_1+1,\mathrm{....},N\end{array}\right.$

Wherein $g\left(n\right)=\mathrm{\α}+\frac{1}{2N_2}\[2(n-N_1)-1\];$

3) according to the correlation structure steering vector between discrete wave beam angle and vertical dimension antenna:

The strong correlation between vertical dimension antenna is utilized to generate steering vector as follows:

$f_n^v=1/\sqrt{N_v}.{\left[\begin{array}{cccc}1& e^{-{\mathrm{j\β}}_n}& ...& e^{-j(N_v-1){\mathrm{\β}}_n}\end{array}\right]}^T$

Wherein ${\mathrm{\β}}_n=\frac{2\mathrm{\π}}{\mathrm{\λ}}{d}_{v}sin\left({\mathrm{\θ}}_n\right)$ Represent the phase difference that the wave beam of different directions causes due to vertical dimensions antenna distance, N _vrepresent the vertical dimension antenna number of base station UPA, () ^tthe transposition of representing matrix.

3. under a kind of 3DMIMO channel according to claim 2 based on the vertical dimension codebook design method of non-uniformly distributed load, it is characterized in that: described step 2 specifically comprises:

Horizontal dimension code book F ^(h)generated by rotation DFT, (n, m) the individual element wherein in g sub-codebook is calculated as follows:

$F_g^{\left(h\right)}(n,m)=1/\sqrt{N_h}.\exp \left(j2\mathrm{\π}\frac{n}{N_h}\right(m+g/G\left)\right)$

Wherein n=1 .., N _h; M=1 ..., N _h; G=1 ..., G, N _hfor horizontal dimension antenna number, G represents the sub-codebook number of horizontal dimension; Combined level dimension code book and vertical dimension code book, utilizes Kronecker to amass the precoding codebook of computing structural plane to 3D-MIMO, and q sub-codebook in the precoding codebook of wherein 3D-MIMO is calculated as follows:

$F_q^{3D}=F_g^{\left(h\right)}\⊗f_n^v,$

Wherein n=1 .., N; G=1 ..., G; Q=gn, easily knows F ^3Din include G × N number of sub-codebook.