CN101841359B

CN101841359B - Data transmission method and system based on channel Quality to Interference Ratio

Info

Publication number: CN101841359B
Application number: CN201010190425.5A
Authority: CN
Inventors: 卢光跃; 孙宝玉
Original assignee: Xi'an Post & Telecommunication College
Current assignee: Xi'an Post & Telecommunication College
Priority date: 2010-06-03
Filing date: 2010-06-03
Publication date: 2014-07-09
Anticipated expiration: 2030-06-03
Also published as: CN101841359A

Abstract

The invention discloses a limited feedback beamforming data transmission method and system based on the channel quality-to-interference ratio as the quantification criterion, which specifically includes the following steps: designing a DFTC codebook by referring to the discrete Fourier transform; QIR (Quality to Interference Ratio, QIR) quantization criterion; through this criterion, the quality of the overall quantized channel and the reduction of mutual interference between sub-channels can be considered at the same time, and the proportional fairness algorithm (PFS) is used to schedule users and the water injection algorithm Allocate power to the scheduled users; use the optimal code word fed back by the user as the beam vector to transmit data to the user. The present invention overcomes the defects of system performance degradation when there are few users in the traditional beamforming mode, rapid increase in system feedback amount when there are many users, and system performance degradation in low SNR scenarios, and is a relatively good beamforming scheme.

Description

Data transmission method and system based on channel quality to interference ratio

技术领域 technical field

本发明涉及无线通信领域，特别涉及一种基于信道质量干扰比为量化准则的有限反馈波束形成数据传输的方法和系统。The present invention relates to the field of wireless communication, in particular to a method and system for data transmission of limited feedback beamforming based on channel quality to interference ratio as a quantization criterion.

背景技术 Background technique

MIMO(Multiple-Input Multiple-Output，多输入多输出)通信系统通过采用多根发射和接收天线而具有较高的空间复用增益和分集增益，并能够在多用户系统中通过波束形成和用户调度技术获得显著的多用户分集增益和多路复用增益，因此它被LTE-Advanced标准采用，也必将成为4G无线通信系统的关键技术。在MIMO系统中，可以利用波束形成技术获得一定的波束形成增益，改善系统性能，但是，常规的波束形成技术在少用户时系统性能明显下降，且在多用户时反馈量过大，尤其在低信噪比(Signal toNoise Ratio，SNR)场景下系统性能下降更是明显。MIMO (Multiple-Input Multiple-Output) communication system has high spatial multiplexing gain and diversity gain by using multiple transmitting and receiving antennas, and can be used in multi-user systems through beamforming and user scheduling The technology obtains significant multi-user diversity gain and multiplexing gain, so it is adopted by the LTE-Advanced standard and will become the key technology of the 4G wireless communication system. In a MIMO system, beamforming technology can be used to obtain a certain beamforming gain and improve system performance. However, the system performance of conventional beamforming technology is significantly reduced when there are few users, and the amount of feedback is too large when there are many users, especially at low The system performance degradation is more obvious in the Signal to Noise Ratio (SNR) scenario.

目前，一种采用随机波束形成(Random Beamforming，RBF)模式的无线通信技术，具有波束形成简单，反馈复杂度低、反馈量少、且在多用户时能获得与在发射机完全知道信道状态信息(Channel State Information，CSI)并利用脏纸编码(Dirty-Paper Coding，DPC)技术时相同增长速度的系统吞吐量等优点，因此广泛受到重视。但是，该技术采用的波束矢量是随机生成，尤其在少用户时系统无法找到与其匹配的调度用户，因此系统性能严重下降。At present, a wireless communication technology using random beamforming (Random Beamforming, RBF) mode has the advantages of simple beamforming, low feedback complexity, less feedback, and can obtain and fully know the channel state information at the transmitter when there are multiple users. (Channel State Information, CSI) and the advantages of system throughput at the same growth rate when using dirty paper coding (Dirty-Paper Coding, DPC) technology, so it has been widely valued. However, the beam vector used in this technology is randomly generated, especially when there are few users, the system cannot find matching scheduling users, so the system performance is seriously degraded.

为了解决以上问题，采用特征波束形成(Eigen Beamforming，EBF)模式的无线通信技术，该技术要求完全反馈用户CSI，并把反馈回来的用户信道奇异值分解的右奇异矢量作为波束矢量，因此即使在少用户下，波束也与用户信道完全匹配，大大改善系统在少用户时的系统性能，但是，随着用户数的增多，系统反馈量严重增大，占用宝贵的系统资源，因此无法广泛应用。In order to solve the above problems, the wireless communication technology of Eigen Beamforming (EBF) mode is adopted. This technology requires complete feedback of user CSI, and the right singular vector of the feedback user channel singular value decomposition is used as the beam vector. Therefore, even in When there are few users, the beam also completely matches the user channel, which greatly improves the system performance of the system when there are few users. However, as the number of users increases, the amount of system feedback increases seriously, occupying valuable system resources, so it cannot be widely used.

此外，相干机会波束形成(Coherent Opportunistic Beamforming，COBF)模式采用用户归一化信道矢量作为最优的波束形成矢量，该模式在低SNR场景下可以获得接近DPC的系统性能，但是它要求基站必须精确地知道用户的CSI，此外，该模式没有采用码本方案，因此实际中很难应用。In addition, the coherent opportunistic beamforming (Coherent Opportunistic Beamforming, COBF) mode uses the user normalized channel vector as the optimal beamforming vector. This mode can obtain system performance close to DPC in low SNR scenarios, but it requires the base station to be accurate The user's CSI is well known. In addition, this mode does not use a codebook scheme, so it is difficult to apply in practice.

发明内容 Contents of the invention

本发明实施例要解决的问题是提供一种基于信道质量干扰比为量化准则的有限反馈波束形成数据传输方法和系统，以克服现有传统波束形成模式(RBF、EBF和COBF)在少用户下系统性能下降、在多用户时系统反馈量剧增的缺陷，以及在低SNR场景下系统性能下降的问题。The problem to be solved by the embodiments of the present invention is to provide a limited feedback beamforming data transmission method and system based on the channel quality-to-interference ratio as the quantization criterion, so as to overcome the disadvantages of the existing traditional beamforming modes (RBF, EBF and COBF) in the case of fewer users. System performance degradation, the defect that the amount of system feedback increases sharply when there are multiple users, and the problem of system performance degradation in low SNR scenarios.

为达到以上目的，本发明提供一种数据传输的方法，包括以下步骤：系统模型简介；DFTC码本设计；QIR准则及其对应的量化准则的设计；新的波束形成过程；系统容量分析、功率分配和用户调度算法。In order to achieve the above object, the present invention provides a method for data transmission, comprising the following steps: a brief introduction to the system model; DFTC codebook design; design of the QIR criterion and its corresponding quantization criterion; new beamforming process; system capacity analysis, power Allocation and user scheduling algorithms.

其中，系统模型简介如下：Among them, the introduction of the system model is as follows:

本发明假设发射端配置M个天线，接收端配置N个天线，基站和用户都处于丰富散射体的环境，第m根发射天线到第n个接收天线的信道系数为h_nm，它们均服从独立复高斯分布CN(0，1)。假设信道为块衰落信道，即在码元传输的时间内为平坦衰落且保持不变，不同用户之间的信道相互独立。第k个用户在时隙t的接收信号为：The present invention assumes that the transmitting end is configured with M antennas, the receiving end is configured with N antennas, the base station and the user are in an environment rich in scatterers, the channel coefficient from the mth transmitting antenna to the nth receiving antenna is h _nm , and they all obey the independent Complex Gaussian distribution CN(0,1). Assume that the channel is a block fading channel, that is, it is flat fading and remains unchanged during the symbol transmission time, and the channels between different users are independent of each other. The received signal of the kth user in time slot t is:

Y_k(t)＝H_k(t)X_k(t)+Φ_k(t)Y _k (t)＝H _k (t)X _k (t)+Φ _k (t)

其中，Y_k(t)∈C^N表示用户k在时隙t的接收信号；H_k(t)∈C^N×M表示用户k在时隙t的复高斯信道；X_k(t)∈C^M表示基站在时隙t的发送符号；Φ_k(t)∈C^N表示用户k在时隙t接收到的加性复高斯白噪声信号，其功率为N_Φ。假定基站总发射功率为下面为方便讨论均省去时隙t。Among them, Y _k (t)∈C ^N represents the received signal of user k at time slot t; H _k (t)∈C ^N×M represents the complex Gaussian channel of user k at time slot t; X _k (t)∈C ^M represents the symbol transmitted by the base station at time slot t; Φ _k (t)∈C ^N represents the additive complex white Gaussian noise signal received by user k at time slot t, and its power is N _Φ . Assume that the total transmit power of the base station is The time slot t is omitted below for the convenience of discussion.

其中，DFTC码本设计如下：Among them, the DFTC codebook is designed as follows:

码本集合为C＝{C⁽⁰⁾，...，C^(G-1)}，其中，G＝2^B，B是量化比特。基于DFT的码本生成方法如下，是第g个预编码矩阵，保证预编码矩阵是一个酉矩阵，其中是该预编码矩阵中的第m个预编码向量，其每一个元素基于傅立叶基生成，如下：The codebook set is C={C ⁽⁰⁾ , . . . , C ^(G-1) }, where G=2 ^B , and B is a quantization bit. The DFT-based codebook generation method is as follows, is the g-th precoding matrix, and it is guaranteed that the precoding matrix is a unitary matrix, where is the mth precoding vector in the precoding matrix, each element of which is generated based on the Fourier basis, as follows:

${c c}_{m m}^{((g g))} = = \frac{11}{\sqrt{M m}} {[[{c c}_{00 m m}^{((g g))},, . . . . . .,, {c c}_{((M m - - 11)) m m}^{((g g))}]]}^{T T}$

${c c}_{nm nm}^{((g g))} = = exp exp {{j j \frac{22 πn πn}{M m} ((m m + + \frac{g g}{G G}))}},, m m,, n no,, = = 00,, . . . . . .,, M m - - 11,, g g = = 11,, . . . . . .,, G G$

其中，QIR准则及其对应的量化准则的设计，具体包括：Among them, the design of the QIR criterion and its corresponding quantification criterion specifically includes:

接收端通过信道估计可以知道自己的CSI，对H_k做奇异值(SVD)分解，即U_k、V_k是酉矩阵，Λ_k是H_k奇异值组成的对角矩阵。为了同时考虑用户k总体信道量化质量好坏和量化子信道之间正交性大小，定义质量干扰比(QIR，质干比)参数，即：The receiving end can know its own CSI through channel estimation, and perform singular value (SVD) decomposition on H _k , that is U _k and V _k are unitary matrices, and Λ _k is a diagonal matrix composed of singular values of H _k . In order to simultaneously consider the overall channel quantization quality of user k and the orthogonality between quantized sub-channels, the quality-to-interference ratio (QIR, quality-to-interference ratio) parameter is defined, namely:

${QIR QIR}_{k k}^{((g g))} = = \frac{{Σ Σ}_{m m = = 11}^{M m} {| | {[[{V V}_{k k}^{H h} {C C}^{((g g))}]]}_{mm mm} | |}^{22}}{{| | | | {V V}_{k k}^{H h} {C C}^{((g g))} | | | |}_{F f}^{22} - - {Σ Σ}_{m m = = 11}^{M m} {| | {[[{V V}_{k k}^{H h} {C C}^{((g g))}]]}_{mm mm} | |}^{22}} = = \frac{{Σ Σ}_{m m = = 11}^{M m} {| | {[[{V V}_{k k}^{H h} {C C}^{((g g))}]]}_{mm mm} | |}^{22}}{{Σ Σ}_{\underset{m m &NotEqual; &NotEqual; n no}{m m = = 11,, n no = = 11}}^{M m} {| | {[[{V V}_{k k}^{H h} {C C}^{((g g))}]]}_{mn mn} | |}^{22}},, k k = = 11,, . . . . . .,, K K,, m m = = 11,, . . . . . .,, M m$

其中，表示矩阵的对角线元素，表示当用户k选择第g个码本时的质干比大小，其分子表示采用波束形成后用户k所有子信道质量信息，而其分母表示采用波束形成后用户k所有子信道之间互干扰情况。因此，能同时包含用户k所有子信道质量信息和子信道之间互干扰信息，越大，表示用户k的子信道质量越好，且子信道之间互干扰越弱，这是采用QIR作为量化标准的优点所在。基于QIR量化准则如下。in, representation matrix The diagonal elements of Indicates the mass-to-interference ratio when user k selects the g-th codebook, its numerator represents the quality information of all sub-channels of user k after beamforming is adopted, and its denominator represents the mutual interference between all sub-channels of user k after beamforming . therefore, Can simultaneously contain all sub-channel quality information of user k and mutual interference information between sub-channels, The larger is, the better the sub-channel quality of user k is, and the weaker the mutual interference between sub-channels is, which is the advantage of using QIR as the quantization standard. The QIR-based quantization criterion is as follows.

所述最优码字索引由公式The optimal codeword index is given by the formula

${\overset{^^}{g g}}_{k k} = = arg arg \underset{11 \leq \leq g g \leq \leq G G}{max max} {QIR QIR}_{k k}^{((g g))},, k k = = 11,, . . . . . .,, K K$

其中，是用户k的最优码字索引。in, is the optimal codeword index for user k.

其中，波束形成过程简述如下，具体包括：Among them, the beamforming process is briefly described as follows, including:

基站收集所有在线用户反馈的最优码字索引，根据用户反馈的码字索引从码本中找出对应码字作为该用户的CSI量化值，并作为其波束形成矢量，因此用户k的波束形成矢量为：The base station collects the optimal codeword index fed back by all online users, and finds the corresponding codeword from the codebook according to the codeword index fed back by the user as the CSI quantization value of the user, and uses it as its beamforming vector, so the beamforming of user k The vector is:

${B B}_{k k} = = {C C}^{(({\overset{^^}{g g}}_{k k}))}$

给传输信号X_k左乘预编码矩阵B_k，则在天线上发射信号为B_kX_k；在接收端，接收信号Y_k左乘则用户k的接收信号为：Multiply the precoding matrix B _k to the left of the transmitted signal X _k , then the transmitted signal on the antenna is B _k X _k ; at the receiving end, the received signal Y _k is left multiplied by Then the received signal of user k is:

${\overset{^^}{Y Y}}_{k k} = = {U u}_{k k}^{H h} (({H h}_{k k} {B B}_{k k} {X x}_{k k})) + + {U u}_{k k}^{H h} {Φ Φ}_{k k} = = {Λ Λ}_{k k} {V V}_{k k}^{H h} {B B}_{k k} {X x}_{k k} + + {\overset{^^}{Φ Φ}}_{k k}$

其中，系统容量分析、功率分配和用户调度算法如下，具体包括：Among them, the system capacity analysis, power allocation and user scheduling algorithms are as follows, including:

首先分析系统容量和功率分配算法；令用户k在第r个子First analyze the system capacity and power allocation algorithm; let User k's rth child

信道的有效信噪比(Effective SNR，ESNR)为：The effective signal-to-noise ratio (Effective SNR, ESNR) of the channel is:

${γ γ}_{k k}^{r r} = = \frac{{λ λ}_{k k}^{r r} {ψ ψ}_{rr rr}}{{λ λ}_{k k}^{r r} \underset{j j,, r r &NotEqual; &NotEqual; j j}{Σ Σ} {ψ ψ}_{rj r j} + + {σ σ}_{r r}^{22}}$

其中，ψ_rj是矩阵ψ_k的第r行j列元素值，是第k个用户信道矩阵H_k的第r个奇异值，是第r个子信道的噪声功率。基站根据被调度用户k的反馈值，可用注水算法最大化系统容量，采用注水算法后吞吐量由公式Among them, ψ _rj is the element value of row j and column j of matrix ψ _k , is the rth singular value of the kth user channel matrix H _k , is the noise power of the rth subchannel. According to the feedback from the scheduled user k, the base station value, the water injection algorithm can be used to maximize the system capacity, and the throughput after using the water injection algorithm is given by the formula

确定，其中表示max(0，A)，R表示有效子信道个数。OK, where Indicates max(0, A), and R indicates the number of effective sub-channels.

其次采用经典的比例公平(Proportional Fairness Scheduling，PFS)用户调度算法，简述如下，所述被调度的用户由公式Secondly, the classic proportional fairness (Proportional Fairness Scheduling, PFS) user scheduling algorithm is adopted, which is briefly described as follows, and the scheduled users are determined by the formula

${k k}^{* *} ((t t)) = = arg arg \underset{11 \leq \leq k k \leq \leq K K}{max max} \frac{{R R}_{k k} ((t t))}{{C C}_{k k} ((t t))}$

确定。其中用户k速率更新公式为：Sure. The user k rate update formula is:

${C C}_{k k} ((t t + + 11)) = = \{\begin{matrix} ((11 - - \frac{11}{{t t}_{c c}})) {C C}_{k k} ((t t)) + + \frac{11}{{t t}_{c c}} {R R}_{k k} ((t t)),, & k k = = {k k}^{* *} \\ ((11 - - \frac{11}{{t t}_{c c}})) {C C}_{k k} ((t t)) & k k &NotEqual; &NotEqual; {k k}^{* *} \end{matrix}$

其中R_k(t)为用户在时隙t的需求速率，t_c为时间常数。Among them, R _k (t) is the demand rate of the user in the time slot t, and t _c is the time constant.

本发明还提供了一种数据传输的系统，包括：基站端采用DFTC码本C，并利用该码本C向用户设备发送多个不同的训练序列符号；用户设备，采用基于QIR为量化准则量化信道状态信息，并向基站反馈每个用户所需的最优码字索引；然后利用ESNR准则计算其值；基站端，根据每个用户反馈的码字索引和ESNR值，计算其吞吐量，并结合PFS算法选择出最优调度用户。同时，采用注水算法给该用户的各个子信道动态分配功率和采用波束形成技术给其传输数据。The present invention also provides a system for data transmission, including: the base station uses a DFTC codebook C, and uses the codebook C to send a plurality of different training sequence symbols to the user equipment; the user equipment uses QIR as the quantization criterion for quantization channel state information, and feed back the optimal codeword index required by each user to the base station; then use the ESNR criterion to calculate its value; the base station calculates its throughput according to the codeword index and ESNR value fed back by each user, and Combined with the PFS algorithm, the optimal scheduling user is selected. At the same time, the water filling algorithm is used to dynamically allocate power to each sub-channel of the user and the beamforming technology is used to transmit data to it.

其中，所述基站端包括：Wherein, the base station includes:

基站采用DFTC码本；收集所有用户反馈的最优码字索引和有效信噪比值；并基于以上反馈参数采用PFS算法找出系统最佳调度用户；给最佳调度用户采用注水算法动态分配功率和使用其最优DFTC码字传输数据。The base station uses the DFTC codebook; collects the optimal codeword index and effective SNR value fed back by all users; and uses the PFS algorithm to find the best scheduling user in the system based on the above feedback parameters; uses the water injection algorithm to dynamically allocate power to the best scheduling user and transmit data using its optimal DFTC codeword.

其中，所述用户设备包括：Wherein, the user equipment includes:

最优码字获取单元，用于获取每个用户的最优码字；所有子信道有效信噪比获取单元，用于用户获取其所有子信道的有效信噪比值；The optimal codeword acquisition unit is used to obtain the optimal codeword of each user; the effective signal-to-noise ratio acquisition unit of all sub-channels is used for the user to obtain the effective signal-to-noise ratio values of all sub-channels;

与现有波束形成(RBF、EBF和COBF)等模式相比，本发明的技术方案具有如下优点：Compared with existing modes such as beamforming (RBF, EBF and COBF), the technical solution of the present invention has the following advantages:

本发明既适合少用户场景，也适合多用户场景和低SNR场景，同时降低系统反馈量，提高系统性能。The present invention is not only suitable for the scene of few users, but also suitable for the scene of many users and the scene of low SNR, and at the same time reduces the amount of system feedback and improves the system performance.

附图说明 Description of drawings

图1本发明实施例的一种数据传输系统的结构框图；Fig. 1 is a structural block diagram of a data transmission system according to an embodiment of the present invention;

图2本发明实施例的一种数据传输系统的流程图；Fig. 2 is a flow chart of a data transmission system according to an embodiment of the present invention;

图3本发明与传统波束形成系统(RBF、EBF)的吞吐量的仿真结果比较数值示意图(本发明简称：QBF，Quantization Beamforming)；Fig. 3 is a numerical schematic diagram comparing the simulation results of the throughput of the present invention and the traditional beamforming system (RBF, EBF) (abbreviated in the present invention: QBF, Quantization Beamforming);

图4本发明在不同SNR下系统吞吐量的仿真结果比较数值示意图；Fig. 4 is a numerical schematic diagram of the comparison of the simulation results of the system throughput under different SNRs in the present invention;

具体实施方式 Detailed ways

下面结合附图和实施例，对本发明的具体实施方式作进一步详细描述。The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

实施例1Example 1

一种基于信道质量干扰比为量化准则的有限反馈波束形成数据传输方法和系统的结构框图如图1所示，包括下列步骤：A structural block diagram of a limited feedback beamforming data transmission method and system based on channel quality to interference ratio as a quantization criterion is shown in Figure 1, including the following steps:

步骤s201，在基站端，DFTC的生成，具体过程为：Step s201, at the base station, the generation of DFTC, the specific process is:

码本集合为C＝{C⁽⁰⁾，...，C^(G-1)}，基于DFT的码本生成方法如下，是第g个预编码矩阵，保证预编码矩阵是一个酉矩阵，其中是该预编码矩阵中的第m个预编码向量，其中每一个元素基于傅立叶基生成，如下：The codebook set is C={C ⁽⁰⁾ ,...,C ^(G-1) }, and the codebook generation method based on DFT is as follows, is the g-th precoding matrix, and it is guaranteed that the precoding matrix is a unitary matrix, where Is the mth precoding vector in the precoding matrix, where each element is generated based on the Fourier basis, as follows:

${c c}_{nm nm}^{((g g))} = = exp exp {{j j \frac{22 πn πn}{M m} ((m m + + \frac{g g}{G G}))}},, m m,, n no = = 00,, . . . . . .,, M m - - 11,, g g = = 11,, . . . . . .,, G G$

步骤s202，基站利用DFTC码本向用户设备发送多个不同的训练序列符号。Step s202, the base station sends multiple different training sequence symbols to the user equipment by using the DFTC codebook.

步骤s203，用户设备向基站反馈最优量化码字索引和对应的ESNR值。所述最优量化码字索引由公式In step s203, the user equipment feeds back the optimal quantization codeword index and the corresponding ESNR value to the base station. The optimal quantization codeword index is given by the formula

确定，其中QIR是用户k在不同码字下的信道质量干扰比(QIR)数值，由公式Determine, where QIR is the channel quality-to-interference ratio (QIR) value of user k under different codewords, by the formula

确定；Sure;

所述ESNR由公式The ESNR is given by the formula

${γ γ}_{k k}^{r r} = = \frac{{λ λ}_{k k}^{r r} {ψ ψ}_{rr rr}}{{λ λ}_{k k}^{r r} \underset{j j,, r r &NotEqual; &NotEqual; j j}{Σ Σ} {ψ ψ}_{rj r j} + + {σ σ}_{r r}^{22}},, k k = = 11,, . . . . . .,, K K,, r r = = 11,, . . . . . .,, R R$

确定。Sure.

步骤s204，基站调度用户并采用波束形成技术给对应的用户传输数据。具体过程为：基站收集小区所有活动用户的并计算其容量，采用比例公平调度(PFS)算法调度用户；所述调度的用户设备用公式In step s204, the base station schedules users and transmits data to corresponding users using beamforming technology. The specific process is: the base station collects the information of all active users in the cell And calculate its capacity, adopt Proportional Fair Scheduling (PFS) algorithm to dispatch users; The user equipment of described dispatch uses formula

确定；Sure;

对调度的用户根据其采用注水算法动态分配功率，并给调度的用户采用波束形成技术传输数据；For scheduled users according to their Use water injection algorithm to dynamically allocate power, and use beamforming technology to transmit data to scheduled users;

其中，本发明实施例系统性能和传统波束形成模式的系统性能比较仿真结果示意图如图3所示；本发明实施例系统平均吞吐量与SNR关系比较仿真结果分别如图4所示(其中M＝2，N＝2)。Among them, the schematic diagram of the system performance of the embodiment of the present invention and the system performance comparison simulation result of the traditional beamforming mode is shown in Figure 3; 2, N=2).

本发明实施例的一种数据传输的系统：基站端采用DFTC码本C，并利用该码本C向用户设备发送多个不同的训练序列符号；用户设备，采用基于QIR为量化准则量化信道状态信息，并向基站反馈每个用户所需的最优码字索引；然后利用ESNR准则计算其值；基站，根据每个用户反馈的码字索引和ESNR值，计算其吞吐量，并结合PFS算法选择出最优调度用户；同时，采用注水算法给该用户的子信道分配功率和采用波束形成技术传输数据。A data transmission system according to an embodiment of the present invention: the base station uses the DFTC codebook C, and uses the codebook C to send multiple different training sequence symbols to the user equipment; the user equipment uses QIR as the quantization criterion to quantize the channel state information, and feed back the optimal codeword index required by each user to the base station; then use the ESNR criterion to calculate its value; the base station calculates its throughput according to the codeword index and ESNR value fed back by each user, and combines the PFS algorithm Select the optimal scheduling user; at the same time, use the water filling algorithm to allocate power to the user's sub-channel and use beamforming technology to transmit data.

基站端包括，基站采用DFTC码本；收集所有用户反馈的最优码字索引和有效信噪比值(ESNR)；并基于以上反馈参数采用PFS算法找出系统最佳调度用户；给最佳调度用户采用注水算法分配功率和使用其最优DFTC码字做波束形成传输数据。The base station includes that the base station adopts the DFTC codebook; collects the optimal codeword index and effective signal-to-noise ratio (ESNR) fed back by all users; and uses the PFS algorithm to find the best scheduling user in the system based on the above feedback parameters; Users use the water-filling algorithm to allocate power and use their optimal DFTC codewords for beamforming to transmit data.

用户设备包括最优码字获取单元，用于获取每个用户的最优码字；所有子信道有效信噪比获取单元，用于用户获取其所有子信道的效信噪比值；The user equipment includes an optimal codeword acquisition unit for obtaining the optimal codeword for each user; an effective signal-to-noise ratio acquisition unit for all sub-channels for the user to obtain the effective signal-to-noise ratio values of all its sub-channels;

本发明的主要特点是设计出基于QIR的量化准则，它可以同时考虑到系统总体量化质量和用户子信道之间的互干扰性，基于此准则，保证调度的用户同时具有等效信道质量最大和子信道之间互干扰最小，从而改善系统性能，这是目前所有量化准则不具备的性能，另外本发明还采用DFTC码本，进一步降低系统反馈量，节省系统资源开销。The main feature of the present invention is to design a quantization criterion based on QIR, which can simultaneously consider the overall quantization quality of the system and the mutual interference between user sub-channels. Mutual interference between channels is minimized, thereby improving system performance, which is not available in all quantization criteria at present. In addition, the present invention also adopts DFTC codebook to further reduce system feedback amount and save system resource overhead.

应当理解的是，对本领域普通技术人员来说，可以根据上述说明加以改进或变换，而所有这些改进和变换都应属于本发明所附权利要求的保护范围。It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

Claims

1. A data transmission method based on channel quality to interference ratio, it is characterized in that, comprises the following steps: adopt discrete Fourier base code book C, as beamforming matrix; Utilize described beamforming matrix C to send multiple different training symbols; the users estimate their respective channel information according to the received training symbols, and quantize the channel information based on the channel quality-to-interference ratio QIR as a quantization criterion, select their own optimal codewords from the codebook C, and Feedback the codeword index to the base station; at the same time, the user calculates the effective signal-to-noise ratio ESNR of the sub-channel according to the optimal codeword and the channel information, and feeds back the ESNR to the base station; the base station ESNR schedules the best service user, and uses the optimal codeword fed back for beamforming to transmit data to the user. the

2. the method for claim 1 is characterized in that, the generation process of described discrete Fourier base codebook is as follows: codebook set is C={C ⁽⁰⁾ , ..., C ^{(G- 1)} }, wherein, G=2 ^B , B is the quantization bit; wherein, is the gth precoding matrix, and it is guaranteed that the precoding matrix is a unitary matrix, where Is the mth precoding vector in the precoding matrix, where each element is generated based on the Fourier basis, as follows:

M is the number of antennas configured at the transmitting end, and n is an antenna serial number. the

3. The method according to any one of claims 1 to 2, wherein the QIR criterion is as follows: channel matrix H _k is decomposed into singular value SVD, namely U _k and V _k are unitary matrices, and Λ _k is a diagonal matrix composed of singular values of H _k .

4. the method for claim 3 is characterized in that, described optimal code word index is by formula Determined, where the mass-to-interference ratio parameter Calculate according to the following formula:

in, representation matrix The diagonal elements of ; K is the number of online users, and V _k is the right singular vector of the channel matrix of the kth user.

5. The method according to claim 3, wherein the user k corresponds to the ESNR of the optimal codeword of the user by the formula

sure, where Ψ _rj is the rth row j column element of Ψ _k , is the rth singular value of user k channel matrix H _k , is the noise power of the rth subchannel, is the SNR of user k in the rth sub-channel; V _k is the right singular vector of the channel matrix of the kth user; K is the number of online users, Denotes the beamforming vector of user k, is the optimal codeword index for user k.

6. A transmission system based on the channel quality-to-interference ratio as a quantization criterion, characterized in that it includes: a user and a base station, the base station adopts a DFTC codebook, and utilizes the codebook C to send multiple different The training sequence symbol; the user uses QIR as the quantization criterion to quantize the channel state information and calculate its ESNR value And feed back the optimal codeword index and its ESNR value required by each user to the base station According to the optimal codeword index and the ESNR value fed back by each user, the base station Calculate its throughput, and combine the PFS algorithm to select the optimal scheduling user; use the water filling algorithm to allocate power to the subchannel of the optimal scheduling user and use beamforming technology to transmit data; is the ESNR of user k in the rth subchannel.

7. transmission system as claimed in claim 6, is characterized in that, described base station end comprises: DFTC code book generation unit, is used for generating code book; System parameter collection unit, is used for collecting the optimal code word of all user feedbacks index and effective SNR value The user scheduling unit is used to find the best scheduled users in the cell; the power allocation unit is used to allocate power to the scheduled users using the water filling algorithm; the beamforming unit is used to perform beamforming technology to transmit data to the scheduled users.

8. transmission system as claimed in claim 6, is characterized in that, described user comprises: optimal code word obtaining unit, is used to obtain the optimal code word of each described user; All sub-channel effective signal-to-noise ratio obtaining units , for the user to obtain the effective SNR values of all sub-channels. the