CN100493053C - Method for channel estimation in multi-antenna system - Google Patents

Method for channel estimation in multi-antenna system Download PDF

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CN100493053C
CN100493053C CN 200510039284 CN200510039284A CN100493053C CN 100493053 C CN100493053 C CN 100493053C CN 200510039284 CN200510039284 CN 200510039284 CN 200510039284 A CN200510039284 A CN 200510039284A CN 100493053 C CN100493053 C CN 100493053C
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channel
matrix
pilot
channel estimation
estimation
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CN1688143A (en
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高西奇
尤肖虎
彬 江
潘志文
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东南大学
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Abstract

多天线系统中信道估计的方法涉及一种多天线系统在双选择性衰落信道环境下的导频设计与信道估计的方法。 The method of multi-antenna channel estimation system relates to a method in a multiple antenna system guide bis selective fading channel environment the design and pilot channel estimation. 在发送端,利用离散傅立叶变换矩阵构造出最小二乘意义上最优的循环正交导频序列,并将其间歇地插入发送数据以组成双循环的时隙结构;在接收端,利用循环正交序列的特性,以低的实现复杂度进行最小均方误差意义上最优的最小二乘信道估计,利用接收导频矩阵的分解,进行信道估计的快速实现,利用离散余弦变换进行导频段更为精确的信道估计和噪声方差估计,再采用离散余弦变换域的插值获得数据段信道参数的估计。 At the transmitting end, by using the discrete Fourier transform matrix least-squares sense the best constructed cyclic orthogonal pilot sequences, and inserted intermittently transmit data in the time slot structure composed of a double loop; at the receiving end, by the circulation n characteristics of the orthogonal sequence, to a low optimal implementation complexity least square channel estimation meaning of minimum mean square error, using the received pilot matrix decomposition, rapid channel estimation implemented using discrete cosine transform more band guide to accurately estimate the channel and noise variance estimates, and then using the discrete cosine transform domain interpolation to obtain channel parameters estimated data channel segment. 该方法能有效地提高信道估计精度,改善接收机的性能特别是传统信道估计方法难以保证的高速及变速移动情况下接收机的性能。 This method can improve the channel estimation accuracy, improve the performance of a receiver in particular conventional channel estimation performance of the receiver and the transmission of high-speed movement of a method difficult to secure.

Description

多天线系统中信道估计的方法 Multi-antenna system channel estimation method

技术领域 FIELD

本发明涉及一种通过使用多个发送/接收天线来传输高速数据的宽带移动通信系统,尤其涉及一种多天线系统在双选择性衰落信道环境下的导频设计与信道估计的方法· The present invention relates to a broadband mobile communication system for high-speed data transmission by using a plurality of transmit / receive antennas, and particularly to a method for multi-antenna system in the dual guide selective fading channel environment the design and pilot channel estimation ·

背*財 Choi back *

为适应未来发展的需要,超三代移动通信系统必须能够:支持全IP高速分组数据传输,数据速率为数十兆bps (bit per second)甚至数百兆bps;支持高的终端移动性,移动速度高达每小时几百公里;支持高的传输质童,数据业务的误码率低于ΙΟ"6;提供髙的频谱利用率,每赫兹数比特以上;提供高的功率效率,发射功率降低10 dB以上,·有效地支持在用户数据速率、用户容量、服务质ft和移动速度等方面大动态范围的变化。 To meet the needs of future development, ultra-generation mobile communication system must be able to: support full-speed IP packet data transmission, the data rate several ten trillion bps (bit per second) or even several hundred bps; support high terminal mobility, a moving speed several hundred kilometers per hour; child support high transmission quality, the error rate is lower than the data traffic ΙΟ "6; Gao frequency efficiency, the number of bits per hertz above; to provide high power efficiency, reduced transmit power 10 dB above, - effective support changes in user data rate, user capacity, service quality and moving speed ft large dynamic range.

为了提高系统的频谱利用率,采用多天线发送和多天线接收的空中接口机制是一种有效的解决方案·然而,即使在多天线环境下,为了可靠有效的支持高速数据传输,超三代移动通信系统仍然霈要很离的带宽·宽带传输加重了信道的频率选择性衰落现象,从而造成严重的多径干扰;而由终端的髙速移动所导致的多普勒频移现象则加重了信道的时间选择性衰落。 In order to improve the spectrum utilization of the system, the use of multi-antenna transmission and multi-antenna receive air interface mechanism is an effective solution · However, even in a multi-antenna environment, reliable and effective support for high speed data transmission, ultra-generation mobile communication the system still be very Pei-bandwidth broadband transmission from increased frequency selectivity of the channel fading phenomenon, resulting in severe multipath interference; Gao and the speed of the mobile terminal caused by Doppler shift phenomenon is exacerbated channel time selective fading. 因此,在超三代移动通信系统中,信道的衮落是双选择性的· Thus, the ultra-generation mobile communication system, the channel is off Gunn dual-selective

通信系统中的接收机分为相干接收机和非相干接收机两种。 A receiver in a communication system into a coherent receiver and two kinds of non-coherent receiver. 相千接收机痛要在接收端已知信道的冲击响应系数,从而需要在接收端进行信道估计;而非相干接收机则不霈要在接收端已知信道的冲击响应系数,但要求发送信号为正交调制方式,而且在性能上会有3*4dB的损失。 Pain known to one thousand with the receiver at the receiving end of the channel impulse response coefficients, requiring channel estimation at the receiving end; Pei noncoherent receiver is known to the receiving end of the channel impulse response coefficients are not, but requires the transmission signal quadrature modulation system, and there will be a loss in performance of 3 * 4dB. 本发明主要考虑在超三代移动通信系统中占主导地位的相干接收方式。 The present invention is primarily coherent receiver embodiment considered dominant ultra generation mobile communication system.

为了实现相千接收,需要在接收端进行信道估计。 In order to achieve phase one thousand received, channel estimation is required at the receiving end. 为了能够及时准确地估计出信道参数,实际的通信系统常采用基于导频序列的信道估计方法·其基本思想是:在发送端适当位置间歇插入导频,接收端利用导频恢复出导频位置的信道信息,然后利用某种处理手段(如内插、滤波、变换等)获得所有时段的信道信息。 In order to timely and accurately estimate the channel parameters, the actual communication systems often employ channel estimation pilot sequences based · The basic idea is: inserting a pilot at the transmit end position intermittent receiving side using the pilot recovered pilot positions channel information, and then using some processing means (e.g., interpolation, filtering, transformation, etc.) to obtain channel information for all time periods. 这里主要涉及三个问題:(I)发送端导频的选择与插入:(2)接收靖导频位置信道信息获取的方式;(3)通过导频位置获取的信道信息恢复出所有时刻信道的信息。 Here three main problems: (the I) the sending end a pilot selection and insertion: (2) receiving Yasushi guide way pilot position of the channel information acquired; (3) acquired by the pilot position channel information restoring all the time channels information. 本发明主要就这三个问题给出了一种逼近最优性能且实现复杂度低的技术方案。 The present invention presents a approximate the optimal performance and low complexity of the technical solution to these three questions.

发明内容 SUMMARY

技术问雇*本发明的目的是提供一种多天线系统中信道估计的方法,该方法能有效地提高信道估计精度,改善接收机的性能特别是传统信道估计方法难以保证的高速及变速移动情况下接收机的性能。 Technical Q employed * object of the present invention is to provide a method for multi-antenna system channel estimation, the method can improve the channel estimation accuracy, improve speed and shift movement of the receiver performance in particular conventional channel estimation method is difficult to guarantee performance of the receiver.

技术方案:本发明的多天线系统中信道估计的方法,在发送端,利用离散傅立叶变换(DFT)矩阵构造出最小二乘(LS)意义上最优的循环正交导频序列,并将其间歇地插入发送数据以组成双循环的时隙结构:在接收端,利用循环正交序列的特性,以低的实现复杂度进行最小均方误差(MMSE)意义上最优的最小二乘信道估计,利用接收导频矩阵的分解,进行信道估计的快速实现,利用离散余弦变换(DCT)进行导频段更为精确的信道估计和噪声方差估计,再采用离散余弦变换(DCT)插值获得数据段信道参数的估计该方法包括以下几个步骤: Technical Solution: The method of multi-antenna system according to the present invention the channel estimate, at the transmitting end, by using a discrete Fourier transform (DFT) matrix constructed least squares (LS) in the sense of an optimal cycle orthogonal pilot sequences, and transmitting data intermittently inserted in slot structures of two-cycle: at the receiving end, the cycle characteristics by using the orthogonal sequence, to achieve low complexity the minimum mean square error (MMSE) sense optimal least-squares channel estimation using received pilot decomposition pilot matrix, channel estimation fast implementation using discrete cosine transform (DCT) for guiding the band more accurate channel estimation and noise variance estimates, and then using a discrete cosine transform (DCT) obtained by interpolation segment channel the parameter estimation method comprising the following steps:

步骤I)、在发送端,根据多天线系统发送天线的个数衿以及信道的多径个数 The I multipath step number), the sending end, the multi-antenna system of transmitting antennas and the number of channels Gum

P,构造出长度为 P, constructed length

尽最小二乘意义上最优的循环正交导频序列s,并按如下规则生成各发送天线的导频序列: Best least squares sense the best pilot sequence on the orthogonal pilot sequences cycle s, and follow these rules to generate each transmitting antenna:

步骤2)、在接收端,按下面的公式求得一个时隙中各个导频段的信道冲击响应参数估计 Step 2), at the receiving end, the following equation is obtained by the impact of a channel time slot in response to each of the conduction band parameter estimation

步骤3)、在接收端,利用步骤2)估计出的信道冲击响应按如下公式对每个导频段估计一次信道噪声方差,并得到当前时隙的噪声方差估计: Step 3), at the receiving end, using Step 2) estimated channel impulse response according to the following equation for each channel a guide band noise variance estimate, and to obtain the noise variance estimate for the current slot:

步骤4)、在接收端,利用步驟2)估计出的所有导频段的信道冲击响应,将其在DCT域中进行逐点的去噪处理和噪声方差估计,并通过在离散余弦变换DCT域插值得到数据段的信道冲击响应 Step 4), at the receiving end, using step 2) all estimated pilot segment of the channel impulse response, which by-point processing in the DCT domain denoising and noise variance estimates, and by converting the DCT domain interpolation in the discrete cosine data segment obtained channel impulse response

所述方法中循环正交导频序列S由傅立叶变换矩阵构造,且满足循环正交特性:每个发送天线的导频序列由丨循环移位得到;所述的最小二乘是指估计误差的平方和最小·所述的信道冲击响应参数的估计步骤2是对子时隙进行的,利用接收导频矩阵的如下分解,信道冲击响应参数的估计有快速实现算法; The process cycle S orthogonal pilot sequences constructed from the Fourier transform matrix, and satisfies the orthogonality of the cycle: pilot sequences for each transmission antenna obtained by the shift cycle Shu; refers to the least squares estimation error and the minimum squared-estimation of the channel impulse response parameter of step 2 is carried out sub-slot, using the following matrix decomposition received pilot, estimate the channel impulse response parameter of the fast algorithm;

所述方法中循环正交导频序列S由傅立叶变换矩阵构造,且满足循环正交特性;每个发送天线的导频序列由s循环移位得到:所述的最小二乘是指估计误差的平方和最小。 The process cycle S orthogonal pilot sequences constructed from the Fourier transform matrix, and satisfies the orthogonality of the cycle; pilot sequences for each transmission antenna obtained by the shift cycle s: the least squares error estimation means The minimum sum of squares. 步骤2中所述的信道冲击响应参数的估计是对子时隙进行的;利用接收导频矩阵的如下分解,信道冲击响应参数的估计有快速实现算法: Step 2 The impact of channel estimation response parameter is a sub-time slot; using the received pilot matrix decomposition as estimated channel impulse response parameters fast algorithm:

所述的信道冲击响应参数的估计步骤4是在一个时隙内进行的;信道冲击响应参数的去噪以及插值都是在离散余弦变换DCT域中进行的。 The impulse response of the channel parameter estimation step 4 is performed within a time slot; the channel impulse response and the interpolation parameter denoising domain is a discrete cosine transform DCT performed.

有益效果:本发明提供了一种能用于多天线传输系统信道估计的导频序列的构造方法和信道估计方法,按照本发明方法生成的导频序列,能够以较低的运算复杂度实现最小二乘意义上最优的信道估计;同时利用信道的时域相关特性,通过变换域的处理,获取低复杂度的MMSE意义上的近似最优解,进一步提高了信道估计的精度。 Advantageous Effects: The present invention provides a method of constructing a channel estimation and a method for multi-antenna transmission system capable of channel estimation pilot sequences generated according to the method of the present invention the pilot sequence, can be minimal with low computational complexity the least squares sense the best channel estimation; while using time-domain correlation characteristics of the channel, the processing by the transform domain, obtaining a near-optimal solution of low complexity MMSE sense, to further improve the accuracy of channel estimation. 本发明提供的信道估计方法与现有技术相比,能有效地提髙信道估计精度,改善接收机的性能特别是传统信道估计方法难以保证的高速及变速移动情况下接收机的性能。 The channel estimation method provided by the present invention compared to the prior art, can effectively provide Gao channel estimation accuracy, improve the performance of a receiver in particular conventional channel estimation method is difficult to ensure the performance of the receiver and the transmission of the movement of high speed. 这种信道估计方法无需长的导频序列,并且运算量和存储量都很小,便于硬件实现·图I是本发明中采用的间歇导频时隙结构,其中有糖环保护段G、导频段P、数据段D·子时隙数目K根据终端的移动速度自适应调整。 This method does not require channel estimation of the pilot sequence length, and the computation amount and memory capacity are very small, easy hardware implementation - Figure I is employed in the present invention an intermittent pilot frequency time slot structure, wherein the sugar ring is protected segments G, the guide band P, the number of data segments D · K sub-slot adaptively in accordance with the movement speed of the terminal.

图2是本发明中由基本序列构造各天线导频序列的应用方法示意图。 FIG 2 is a schematic view of application of the method of the present invention is configured by a base sequence of each antenna pilot sequences.

图3是本发明中最小二乘信道估计的一种快速实现装置的示意图,其中有对信号顺序进行调整的调序模块;对信号相位进行旋转的相位旋转模块:FFT组与IFFT 组· FIG 3 is a schematic diagram of a present invention, the least squares channel estimation fast implementation apparatus which reordering module for adjusting the signal sequence; phase rotation module for rotating the phase of the signal: FFT and IFFT group set ·

图4是本发明的一种信道估计具体装置方框图。 DETAILED FIG. 4 is a block diagram of the present invention an apparatus for channel estimation. 其中有针对各导频段接收信号的最小二乘信道估计模块;对所有时域估计值进行离散余弦变换的DCT模块;DCT域单点去噪与噪声方差估计模块:对信号进行反离散余弦变换的IDCT模块。 Including least squares estimation module for each frequency channel of the received pilot signal; DCT-block discrete cosine transform domain for all time estimates; single-point DCT domain denoising and noise variance estimation module: the signal inverse discrete cosine transform IDCT module.

具体实财式· 为使本发明的目的、技术方案和优点更加淸楚明白,下面结合附图对技术方案的实施作进一步的详细描述: Specific Choi formula · To make the objectives, technical solutions, and advantages of the present invention will become apparent Qing Chu, in conjunction with the accompanying drawings of embodiments of the technical solutions described in further detail:

在发送端,利用离散傅立叶变换(DFT)矩阵构造出最小二乘(LS)意义上最优的循环正交导频序列,并将其间歇地插入发送数据以组成双循环的时隙结构;在接收端,利用循环正交序列的特性,以低的实现复杂度进行最小均方误差(MMSE)意义上最优的最小二乘信道估计,利用接收导频矩阵的分解,进行信道估计的快速实现,利用离散余弦变换(DCT)进行导频段更为精确的信道估计和噪声方差估计,再采用离散余弦变换(DCT)插值获得数据段信道参数的估计。 At the transmitting end, by using a discrete Fourier transform (DFT) matrix constructed least squares (LS) in the sense of an optimal cycle orthogonal pilot sequences, and inserted intermittently transmit data in the time slot structure composed of a double loop; in the receiving end, the cycle characteristics by using the orthogonal sequence, to achieve low complexity the minimum mean square error (MMSE) sense optimal least-squares channel estimation using received pilot pilot matrix decomposition, channel estimation of fast implementation estimated using a discrete cosine transform (DCT) for guiding the band more accurate channel estimation and noise variance estimates, and then using a discrete cosine transform (DCT) obtained by interpolation segment channel parameters.

该方法包括以下几个步骒: The method includes the following steps Ke:

步骤I)、在发送端,根据多天线系统发送天线的个数乂以及信道的多径个数尸,构造出长度为最小二乘意义上最优的循环正交导频序列s,并按如下规则生成各发送天线的导频序列: The I step), the transmission side, the number of dead multipath multiple antenna system according to the number of transmission antennas and qe channel length construct optimal least-squares sense loop orthogonal pilot sequences s, press follows rule generating each transmission antenna pilot sequences:

步骤2)、在接收端,按下面的公式求得一个时隙中各个导频段的信道冲击响应参数估计 Step 2), at the receiving end, the following equation is obtained by the impact of a channel time slot in response to each of the conduction band parameter estimation

步隳3)、在接收端,利用步嫌2)估计出的信ϋ冲击响应按如下公式对每个导频段估计一次信道嗓声方差,并得到当前时隙的嗓声方差估计: Destroy Step 3), at the receiving end, the use of too-step 2) estimated channel impulse response according to the following equation ϋ each primary channel conduction band voice sound estimation variance, and the resulting current slot throat sound variance estimate:

接收端,利用步骤2)估计出的所有导频段的信道冲击响应,将其在DCT域中进行逐点的去噪处理和噪声方差估计,并通过在DCT域插值得到数据段的信道冲击响应 The receiving end, using Step 2) all estimated pilot segment of the channel impulse response, which denoising and estimation of noise variance in the point-wise DCT domain, and impulse response data obtained by DCT domain interpolation segment in channel

所述方法中循环正交导频序列*由傅立叶变换矩阵构造,且满足循环正交特性:每个发送天线的导频序列由S循环移位得到;所述的最小二乘是指估计误差的平方和最小。 The process cycle * orthogonal pilot sequences constructed from the Fourier transform matrix, and satisfies the orthogonality of the cycle: pilot sequence for each transmit antenna cyclic shifting by S; refers to the least squares estimation error The minimum sum of squares. 所述的信道冲击响应参数的估计步骤2是对子时隙进行的,利用接收导频矩阵的如下分解,信道冲击响应参数的估计有快速实现算法;所述的信道冲击响应参数的估计步磾4是在一个时隙内进行的;信道冲击响应参数的去噪以及插值都是在DCT域中进行的· The impulse response of the channel parameter estimation step 2 sub-time slot is performed, using the received pilot guide below the decomposition matrix, the estimated channel impulse response parameters fast algorithm; the channel impulse response estimate parameters step Midi 4 is performed within a time slot; channel impulse response parameter · denoising and interpolation are carried out in the DCT domain

I.系统祺型 I. Qi-type system

图I给出了发送信号间歇导频时隙结构β设每个时隙中有尤个子时隙,则其导频段的个数为足+1·子时隙数i:可根据终端的移动速度来设定。 Figure I shows the transmitted pilot signal intermittently β slot structure is provided in each slot there are particular sub-slot, the number of its conduction band of a sufficient number of sub-slot + 1 · i: speed of the movable terminal in accordance with set.

在MIMO系统中,设发送天线的个数为AV,接收天线的个数为信道冲击响应序列的长度为P,则每个接收通道待估计的信道参数个数为乂χΡ,相应地,导频序列长度尽(其中 In the MIMO system, the number of transmission antennas is set AV, the number of receiving antennas is the channel number of the channel impulse response length of the sequence of parameters P, then each receiving channel to be estimated for qe χΡ, correspondingly, the pilot sequences to make the length (wherein

1表示不小于X的最小整数)。 1 represents the smallest integer not less X).

use

柃-^表示第η根发送天线的导频序列,则S =[se,s,f表示所有天线的发送导频信号·在接收端去掉循环保护之后的第it个导频段的接收信号可表示为: Eurya - ^ represents η transmit antennas pilot sequence, then S = [se, s, f represents transmission guide all antennas pilot signal which first it received signal conduction band after the receiving end to remove the loop protection may represent for:

【公式I】 [Formula I]

其中0>和Zw是乂XLp的矩阵,分别表示接收到的导频信号和方差为tr2的加性高斯白嗓声; Wherein 0> and Zw are qe XLp matrix, respectively, of the received pilot signal and the variance of the additive white Gaussian tr2 of the voice sound;

是乂欠尽的矩阵,Ag(p)表示在第Jfc个导频段、第 Qe is due to make a matrix, Ag (p) represents the first Jfc a pilot field, first

w根接收天线与第《根发送天线之间第P径的信道抽头系数; w receive antenna corresponds to the "root path between the transmitting antennas of P channel taps coefficients;

L1P - L1P -

由S的列循环右移P位得到的· · S is a right circular column P bits obtained

make

表示在第k个导频段的所有信道参数, All channel parameters indicates the k-th band guide,

则公式I可以改写为: Then the formula I can be rewritten as:

【公式2】 Equation 2

由公式2所描述的线性模型得到信道参数的最小二乘(LS)估计为: Obtained by the linear model described in Equation 2 channel parameters of the least squares (LS) estimation of:

【公式3 】 [Formula 3]

当尽>Λ^Ρ时,可以得到噪声方差的无偏估计量为: When do> Λ ^ Ρ, you can get the noise variance unbiased estimator is:

【公式4】 [Formula 4]

其中||F表示矩阵的F范数。 || F where F represents the norm of a matrix. 理论分析表明,当时,上面的LS估计具有最优的性能,并且避免了矩阵求逆运算· Theoretical analysis shows that, at that time, the above estimate LS has the best performance and avoids matrix inversion ·

2.最优导辦列构造 2. do the best guide column structure

设s = 是长为尽的循环正交序列,我们将其作为基本序列,按如下准则构造各天线的导频序列 Setting s = length of the cycle is to make the orthogonal sequence, as we will base sequence, each antenna configuration according to the following criteria pilot sequence

【公式5】 [Equation 5]

其中表示I*对#的求模运算·可以验证,当》是循环正交序列时,按照公式 Wherein I * represents a modulo operation of # * can verify, when the "when the orthogonal sequence is a loop, according to the formula

5构造的导频序列满足前面的正交条件。 5 pilot sequence constructed orthogonal to satisfy the foregoing conditions.

有关循环正交序列的构造,在文献中已有报道,我们发现Ip == 22"和尽=22"-1的循环正交序列可以从 Construction related to the cycle of the orthogonal sequence, have been reported in the literature, we found 22 "and 22 = best" circulation orthogonal sequence Ip == -1 can be obtained from

点DFT矩阵元素直接得到。 Point DFT matrix element directly. 设W为AT点DFT矩阵,其元素并设W = [W。 AT Let W point DFT matrix, its elements and provided W = [W. W1],其中W。 W1], wherein W. 和W1均为2" X2"·1的子矩Lp = 22"-1,令W = (W。+ jVix)/S,则s -vec{ViT)是长为22"·1的循环正交序列矢量。 And W1 are 2 "X2" · Sub moment Lp 1 = 22 "-1, so that W = (W. + jVix) / S, the s -vec {ViT) length 22 is" orthogonal circular-1 vector sequences. 这里,为拉伸算子· Here, for the stretch operator ·

3.最小二乘侑道估计的实现方法 3. The implementation method of least squares channel estimation Yoo

当矩阵X满足正交条件XXw=尽Ia^时,公式3可以简化为: When orthogonal matrix X satisfying the conditions do XXw = Ia ^, Equation 3 can be simplified to:

接收端在收到Yw之后可直接利用公式6作信道估计,较之公式3的计算,避免了复杂的矩阵求逆运算。 Receiver can receive directly after the Yw equation 6 for channel estimation, compared with formula 3, to avoid the complexity of the matrix inversion. 进一步研究矩阵X的结构,我们发现它有如下两种分解形式: Further study of the structure of the matrix X, we found it to break down in two forms as follows:

公式7中,F是尽点的DFT矩阵,Γ=|也ig{Fa},匕是由置换//生成的WrP阶置换矩阵;公式8中,Λ是尽阶对角阵,PeiPp分别是由置换《,#生成的Zp阶置换矩阵,Q-LJN.其中Λ咕fd丨表示主对角元为d的对角阵,®表示矩阵的Kronecker乘积。 In Equation 7, F is the best point DFT matrix, Γ = | also ig {Fa}, // dagger is generated by the permutation order WrP permutation matrix; In Equation 8, Λ is a diagonal order to make, PeiPp respectively by substitution ", order # Zp generated permutation matrix, Q-LJN. cushions fd Shu wherein Λ represents the main diagonal elements of the diagonal d, matrix ® denotes Kronecker product. 上述各置换的生成规则如下: Each permutation generation rule as follows:

对角阵Λ可以由公式8反推得到其对角元素。 8 diagonal matrix Λ may be extrapolated from its anti-diagonal elements of the formula. 由公式6,7, 8,我们得到初始LS信道估计的三种算法: By Equation 6,7, 8, we obtain an initial three algorithms LS channel estimation:

(1)直接计算(公式6),其复数乘法运算次数为乂&乂尸; (1) direct calculation (Equation 6), the plural number of multiplications is qe qe & corpse;

(2)快速算法一(公式7),其复数乘法运算次数为(I+ Iog2(M)); (2) a fast algorithm (equation 7), which is the number of complex multiplication (I + Iog2 (M));

(3)快速算法二(公式8),其复数乘法运算次数为乂尽(I+ Iog2 V) · (3) two fast algorithm (equation 8), which is the number of complex multiplication qe do (I + Iog2 V) ·

图2给出了一种由公式8实现LS信道估计的装置图》4.更精确的信道估计以上给出了基于单个导频段的最小二乘信道估计和噪声方差估计方法·在双循环自适应时隙结构中,有多个导频段,利用估计出信道参数的时间相关性,可以得到更为精确的信道估计·此外,^Lp-NtP时,无法利用公式4进行噪声方差的估计,此时可以利用信道参数的时间相关性进行嗓声方差的估计。 Figure 2 shows a view of a device realized by Equation 8 LS channel estimation "4 more accurate channel estimation given above and the noise variance estimation least square channel estimation method based on a single pilot band in the adaptive loop bis slot arrangement, a plurality of conductive bands, using the estimated time correlation of channel parameters may be more accurate channel estimation * Further, when ^ Lp-NtP, using equation 4 can not be estimated noise variance, then estimating channel parameters may be utilized correlation time voice sound variance.

记(P)©(P)]',表示第(”,m)传输通道的第;;个径上获得的AT+1个信道参数,则第(m,ri)传输通道上获得的所有信道参数可写为: Note (P) © (P)] ', represents ( ", m) of all channels available on the AT + 1 channel parameters obtained from the first ;; th path transmission channel, then the first (m, ri) transmission channel parameters can be written as:

则有: There are:

其中,Iiitiw为与相应的理想侑道矢量,IU-为零均值白高斯噪声矢量,其各元素的方差为σ1, Lp · Wherein, Iiitiw with the respective channel vectors over Yoo, IU-zero-mean white Gaussian noise vector, each element of which is the variance σ1, Lp ·

由公式9可知,Ive的最小均方误差(MMSE)估计为: Seen from Equation 9, Ive minimum mean square error (MMSE) estimate is:

其中R = qhe>nIiiy ·这里,我们假定各传输通道具有相同的功率延时谱(PDP),进一步,利用信道统计特性在时域与频域可分离的性质,上面的相关阵R可分解为:R=Rzs^Rowf,其中Risf=也4是信道第P径的的功率:Rdp«是由多普勒频移确定的信道时域统计特性·利用R的分解,公式10可以降维实现,即: Wherein R = qhe> nIiiy · Here, we assume that each of the transport channels have the same power delay profile (PDP), further, the use of channel statistics in time and frequency domains detachable nature, the above correlation matrix R can be decomposed into : R = Rzs ^ Rowf, wherein Risf = also 4 is the power channel P-th path is: Rdp «statistical characteristics of the channel time-domain shift is determined by the Doppler-use decomposed R, the equation 10 may be dimension reduction realized, which is:

其中R17 =丑{h叩(p)h^ (/»)} = P2pRdpk。 Wherein R17 = {h ugly knock (p) h ^ (/ »)} = P2pRdpk.

因为Rp是Hermite哞,故可特征分解为·· Rp=UwApU,其中U是正交阵,Λρ=^{Λλ0,Λλ1,...,Λ^}ο利用该特征分解,公式11可改写为_·其中 Since Rp is Hermite moo, wherein it can be decomposed into ·· Rp = UwApU, where U is an orthogonal matrix, Λρ = ^ {Λλ0, Λλ1, ..., Λ ^} ο decomposition With this feature, Equation 11 may be rewritten as _·among them

为了实现O»)的1fflisE估计*霈要实测相关阵并对其进行特征分解·考虑到不同的传输通道具有相同的R,,故可直接利用空间上的样本对Rp进行估计,亦即: In order to achieve O ») * estimate of 1fflisE Pei Found correlation matrix to be decomposed and wherein Taking into account the different transmission channels with the same R ,, it can be directly on the sample space Rp is estimated, i.e.:

为了避免复杂的矩阵特征分解运算,在研究时域相关阵特性的基础上,我们用离散余弦变换(DCT)来逼近相关阵的特征分解,也即用夂+1点的DCT矩阵代替上面的正交阵U,并在DCT变换域进行逐点的去噪处理和噪声方差估计,然后通过反DCT变换获取h„i(1 (/>)MMSE估计的近似解。理论分析和仿真结果都证实此方法是有效的。 In order to avoid decomposition of the complex matrix eigenvalue calculation, the time domain correlation matrix of basic research on the properties, we use the discrete cosine transform (DCT) to approximate the correlation matrix of eigen-decomposition, i.e., instead of the above DCT matrix with n + 1 points Fan deposit matrix U, and point by point in the DCT transform domain denoising processing and noise variance estimates, and h "i (1 approximate solution (/>) MMSE estimate obtained by inverse DCT. theoretical analysis and simulation results have confirmed that this the method is effective.

5.数据段的倍道估计 Times the channel estimation section 5. Data

在获取了导频段的信道参数之后,需要对数据段的信道参数进行跟踪或预测· After acquiring the pilot channel parameter bands, parameter data required for the channel or track segments prediction ·

常用的方法有:线性插值、高斯线性插值、加权多时隙平均(WMSA),这些方法都是简单的线性处理,它们的一个共同缺点是,当移动台速度太快时,信道衰落的变换很快,或出现非线性变化,使得利用导频信道作线性处理得到的数据信道不能真实地反映信道变化情况。 Commonly used methods are: linear interpolation, linear interpolation Gaussian weighted multi-slot averaging (WMSA), these methods are simple linear process, a common drawback thereof is that when the mobile station is too fast speed, fast channel fading transform , or non-linear change occurs, so that the channel using the pilot channel as the linear processing data obtained can not reflect the changes in the channel.

这里我们在DCT域对信道参数进行插值,具体过程如下:首先用尤+ 1点的DCT将(P)变换到DCT域,得到一尤+1维的向量,在其末尾补上(尺+1)(1-1) Here we interpolate the channel parameters in the DCT domain, the specific process is as follows: Firstly, especially with the + DCT 1 point (P) transformed into the DCT domain, in particular to obtain a +1 dimensional vector, in which the end of the complement (ft + 1 ) (1-1)

个零元素,得到维的向量,其中Z是在数据段的插值因子,亦即在每个样值后面插出ZI个值,最后再用点的反DCT变换将其变换回时域。 A zero element, dimensional vector obtained, wherein Z is the interpolation factor in the data segment, i.e., interpolated values ​​in each value ZI behind the sample, then the final point inverse DCT to transform it back into the time domain. 由于DCT插值的边缘效应,尾部的(II)个数据不是很精确,考虑到在后续的检测中并不需要这些数据,故删除尾部的(i-Ι)个数据·插值后得到的信道参数长度为KL+U结合公式12,上述的处理过程可用公式描述为: Since the data edge effect DCT interpolation tail (II) is not very precise, taking into account not need these data in the subsequent detection, it is obtained after removing the trailing the (i-Ι) data-interpolated channel parameter length binding of KL + U equation 12, the above described process can be formulated as:

其中S 是 Where S is

Claims (5)

1 、一种多天线系统中信道估计的方法,其特征在于:在发送端,利用离散傅立叶变换“DFT”矩阵构造出最小二乘“LS”意义上最优的循环正交导频序列S,并将其间歇地插入发送数据以组成双循环的时隙结构;在接收端,利用循环正交序列的特性,以低的实现复杂度进行最小均方误差“MMSE”意义上最优的最小二乘信道估计,利用接收导频矩阵的分解,进行信道估计的快速实现,利用离散余弦变换“DCT”进行导频段更为精确的信道估计和噪声方差估计,再采用离散余弦变换“DCT”插值获得数据段信道参数的估计,该方法包括以下几个步骤: 步骤I)、在发送端,根据多天线系统发送天线的个数以及信道的多径个数P,构造出长度为尽最小二乘意义上最优的循环正交导频序列S,并按如下规则生成各发送天线的导频序列: 1, a multi-antenna channel estimation system, characterized in that: the transmitting side, using a discrete Fourier transform "DFT" constructed matrix least-squares "LS" optimal pilot cycle in the sense orthogonal pilot sequence S, and transmitting data intermittently inserted in the slot structure of the double loop consisting of; at the receiving end, the cycle characteristics by using the orthogonal sequence, with low implementation complexity on the minimum mean squared error "MMSE" best least square sense by channel estimation using the decomposition received pilot matrix quickly realize channel estimation using a discrete cosine transform "DCT" for guiding the band more accurate channel estimation and noise variance estimates, and then using a discrete cosine transform "DCT" obtained by interpolation estimating a channel parameter data channel segment, the method comprising the following steps: the I step), the transmission side, the number of multi-path multi-antenna system according to P and the number of channels transmitting antenna, configured to make the length of the least-squares sense optimal cycle turned on orthogonal pilot sequences S, and follow these rules to generate a pilot sequence for each transmit antenna:
步骤2)、在接收端,按下面的公式求得一个时隙中各个导频段的信道冲击响应参数估计 Step 2), at the receiving end, the following equation is obtained by the impact of a channel time slot in response to each of the conduction band parameter estimation
其中:X是由导频信号组成的矩阵,Yw是第A个子时隙接收到的导频信号; 步骤3)、在接收端,利用步骤2)估计出的信道冲击响应按如下公式对每个导频段估计一次信道噪声方差,并得到当前时隙的噪声方差估计: Wherein: X is a matrix consisting of a pilot signal, Yw A first sub-slots of the received pilot signal; step 3), at the receiving end, using Step 2) estimated channel impulse response for each of the following formula a band guide channel noise variance estimates, and the resulting noise variance estimate for the current slot:
其中:外表示接收天线数; 步骤4)、在接收端,利用步骤2)估计出的所有导频段的信道冲击响应,将其在DCT域中进行逐点的去噪处理和噪声方差估计,并通过在DCT域插值得到数据段的信道冲击响应 Wherein: represents the number of reception antennas outside; step 4), at the receiving end, using step 2) all estimated pilot segment of the channel impulse response, which by-point processing in the DCT domain denoising and noise variance estimates, and impulse response data segment obtained by DCT domain interpolation channel
其中:表示第《根发送天线与第m根接收天线间第/7径信道冲击响应,U和Ξ分别表示DCT矩阵和扩展DCT矩阵,Tp是滤波矩阵。 Wherein: represents the "on / 7-path channel impulse response between the m-th transmitting antennas and receive antennas, U and denote DCT matrix Ξ and extended DCT matrix, Tp is the filter matrix.
2、根据权利要求I所述的多天线系统中信道估计的方法,其特征在于所述方法中循环正交导频序列s由傅立叶变换矩阵构造,且满足循环正交特性;每个发送天线的导频序列由s循环移位得到。 2. The method of channel estimation in multi-antenna system according to claim I, wherein the method s circulating orthogonal pilot sequences constructed from the Fourier transform matrix, and satisfies the orthogonality of the cycle; each transmission antenna the pilot cycle s obtained from sequence shift.
3、根据权利要求I所述的多天线系统中信道估计的方法,其特征在于所述的最小二乘是指估计误差的平方和最小。 3. The method of claim I of the multi-antenna system channel estimation, wherein the least squares means and the minimum square error estimation.
4、根据权利要求I所述的多天线系统中信道估计的方法,其特征在于步骤鱗所述的信道冲击响应参数估计是对子时隙进行的;利用接收导频矩阵的如下分解,信道冲击响应参数的估计有快速实现算法: 4. The method of claim estimated required channels in a multiple antenna system of claim I, wherein the step of the scale parameter of the channel impulse response estimation is performed sub slot; as follows using the received pilot matrix decomposition, channel impulse estimated response parameters of fast algorithm:
其中:Pa,P^, ?„均为置换矩阵,W是DFT变换矩阵,Λ是对角阵,Q为常数。 Wherein:? Pa, P ^, "are permutation matrix, W is the DFT matrix, Λ is a diagonal matrix, Q is a constant.
5、根据权利要求I所述的多天线系统中信道估计的方法,其特征在于步骤2)所述的信道冲击响应参数估计是在一个时隙内进行的;信道冲击响应参数的去噪以及插值都是在离散傅立叶变换“DFT”域中进行的。 5. The method of claim estimated required channels in a multiple antenna system of claim I, wherein the step 2) of the impulse response of the channel parameter estimation is performed within one time slot; the channel impulse response and the interpolation parameter denoising are in the discrete Fourier transform "DFT" field carried out.
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