WO2016119444A1

WO2016119444A1 - Frequency offset estimation method and apparatus, and computer storage medium

Info

Publication number: WO2016119444A1
Application number: PCT/CN2015/087253
Authority: WO
Inventors: 许秋平; 刘源; 王守义
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-01-30
Filing date: 2015-08-17
Publication date: 2016-08-04
Also published as: CN105991484B; CN105991484A

Abstract

Disclosed are a frequency offset estimation method and apparatus, and a computer storage medium. The method comprises: performing frequency offset estimation according to the repeatability of a cyclic prefix (CP), and acquiring a first frequency offset estimated value; acquiring at least one second frequency offset estimated value through a pre-set pilot frequency, and acquiring a wide range of frequency offset estimated values to be selected according to the second frequency offset estimated value and a pre-set operational rule; and acquiring an optimal frequency offset estimated value according to the first frequency offset estimated value, the wide range of frequency offset estimated values to be selected and a pre-set range value.

Description

一种频偏估计的方法、装置及计算机存储介质Method, device and computer storage medium for frequency offset estimation

技术领域Technical field

本发明涉及通信信号处理技术，尤其涉及一种频偏估计的方法、装置及计算机存储介质。The present invention relates to communication signal processing technologies, and in particular, to a frequency offset estimation method and apparatus, and a computer storage medium.

背景技术Background technique

正交频分复用(OFDM，Orthogonal Frequency Division Multiplexing)技术是一种子载波相互正交的多载波传输技术，这种技术要求子载波之间相互正交，并且对载波频率偏移非常敏感；所以，载波频率偏移问题成为当前OFDM技术的核心问题之一。Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier transmission technology in which subcarriers are orthogonal to each other. This technique requires that subcarriers are orthogonal to each other and are very sensitive to carrier frequency offset. The carrier frequency offset problem has become one of the core issues of current OFDM technology.

目前，对于频偏较小的问题，已有很多精度高并且实现简单的方法；但是对于大频偏的问题，通常是采用两种方案：At present, for the problem of small frequency offset, there are many methods with high precision and simple implementation; however, for the problem of large frequency offset, two schemes are usually adopted:

第一种，利用循环前缀(CP，Cyclic Prefix)的重复性来进行频偏估计，但是利用CP进行频偏估计的方法精度不够，最大误差能达到几千赫兹。The first one uses the repeatability of the cyclic prefix (CP, Cyclic Prefix) to perform frequency offset estimation. However, the method of frequency offset estimation using CP is not accurate enough, and the maximum error can reach several kilohertz.

第二种，利用频域中两个小区专属参考信号(CRS，Cell-specific Reference Signals)的导频符号进行频偏估计，但是该方法的频偏估计范围不够大，比如根据一个CRS常规符号对(0，7)或者(4，11)得到的频偏范围为(-1000，1000)Hz，当真实频偏值超过这个范围时，就需要通过不断对真实频偏值加减2000Hz直至结果的范围处于(-1000，1000)Hz范围中，因此会出现大范围频偏值可能是1000Hz，通过进行1000-2000＝-1000Hz的运算出现了频偏翻转的现象。Second, frequency offset estimation is performed by using pilot symbols of two cell-specific reference signals (CRS) in the frequency domain, but the frequency offset estimation range of the method is not large enough, for example, according to a CRS conventional symbol pair. The frequency offset range obtained by (0,7) or (4,11) is (-1000,1000) Hz. When the true frequency offset value exceeds this range, it is necessary to continuously add or subtract 2000 Hz to the true frequency offset value until the result. The range is in the range of (-1000, 1000) Hz, so the large-scale frequency offset value may be 1000 Hz, and the frequency offset is reversed by performing the operation of 1000-2000=-1000 Hz.

发明内容Summary of the invention

为解决上述技术问题，本发明实施例期望提供一种频偏估计的方法、装置及计算机存储介质。In order to solve the above technical problem, an embodiment of the present invention is expected to provide a method for estimating a frequency offset, Device and computer storage media.

本发明实施例的技术方案是这样实现的：The technical solution of the embodiment of the present invention is implemented as follows:

第一方面，本发明实施例提供了一种频偏估计的方法，所述方法包括：In a first aspect, an embodiment of the present invention provides a method for estimating a frequency offset, where the method includes:

根据CP的重复性进行频偏估计，获取第一频偏估计值；Performing a frequency offset estimation according to the repeatability of the CP to obtain a first frequency offset estimation value;

通过预设的导频对获取至少一个第二频偏估计值，并根据所述第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；Acquiring at least one second frequency offset estimation value by using a preset pilot pair, and obtaining a large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and a preset operation rule;

根据所述第一频偏估计值、所述待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。And obtaining an optimal frequency offset estimation value according to the first frequency offset estimation value, the to-be selected large-range frequency offset estimation value, and a preset range value.

上述方案中，所述预设的范围值包括预设的第一范围值和预设的第二范围值，且所述第一范围值小于所述第二范围值；In the above solution, the preset range value includes a preset first range value and a preset second range value, and the first range value is smaller than the second range value;

相应地，根据所述第一频偏估计值、所述待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值，包括：Correspondingly, obtaining an optimal frequency offset estimation value according to the first frequency offset estimation value, the to-be selected large-range frequency offset estimation value, and a preset range value, including:

当所述待选的大范围频偏估计值均处于以所述第一频偏估计值为中心，以所述第一范围值为长度的第一区间内时，所述最优的频偏估计值为所述待选的大范围频偏估计值的平均值；或者，The optimal frequency offset estimation is performed when the to-be selected large-range frequency offset estimation values are all within the first interval with the first frequency offset estimation value and the first range value is the length. a value that is an average of the large range of frequency offset estimates to be selected; or,

当所述待选的大范围频偏估计值中的至少一个处于第二区间时，所述最优的频偏估计值为但处于第二区间的待选的大范围频偏估计值的平均值；其中，所述第二区间为以所述第一频偏估计值为中心，以所述第二范围值为长度的区间减去所述第一区间后得到的区间；或者，When at least one of the to-be selected large-range frequency offset estimation values is in the second interval, the optimal frequency offset estimation value is an average value of the to-be-selected large-range frequency offset estimation values in the second interval. Wherein the second interval is an interval obtained by subtracting the first interval from an interval in which the second range value is the center and the second range value is a length; or

当所述待选的大范围频偏估计值均不处于所述第一区间和所述第二区间时，所述最优的频偏估计值为所述第一频偏估计值。And when the to-be selected large-range frequency offset estimation values are not in the first interval and the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.

上述方案中，所述根据CP的重复性进行频偏估计，获取第一频偏估计值，包括：In the above solution, the performing frequency offset estimation according to the repeatability of the CP, and acquiring the first frequency offset estimation value, includes:

获取CP序列及与所述CP序列相同的原始序列的互相关值cor_CP；Obtaining a cross-correlation value cor_CP of the CP sequence and the original sequence identical to the CP sequence;

根据所述CP序列与所述原始序列的时间差NT_s和所述互相关值 cor_CP，按照下式获取第一频偏估计值f_cp：Obtaining a first frequency offset estimation value f _cp according to the following equation according to a time difference NT _{s of} the CP sequence and the original sequence and the cross-correlation value cor_CP:

其中，angle(·)表示复数向量·和实轴正方向的夹角。Where angle(·) represents the angle between the complex vector and the positive direction of the real axis.

上述方案中，所述通过预设的导频对获取至少一个第二频偏估计值，包括：In the foregoing solution, the obtaining, by using the preset pilot pair, the at least one second frequency offset estimation value includes:

将所述导频对的符号进行共轭相乘之后，再将相乘的结果进行累加，获取累加后的角度值

After conjugate multiplying the symbols of the pilot pair, the multiplied results are accumulated to obtain the accumulated angle values.

将累加后的角度值

以及导频对的符号之间的时间差Δt，按照下式获取所述第二频偏估计值f_Δ：The angle value after the accumulation

And the time difference Δt between the symbols of the pilot pair, the second frequency offset estimated value f _{Δ is} obtained according to the following formula:

其中，f_Δ中的下标Δ表示所述导频对的导频序号差值，

的取值范围是(-π，π)，f_Δ的范围是：

Wherein the subscript _Δ in f _Δ represents the pilot sequence difference value of the pilot pair,

The range of values is (-π, π), and the range of f _Δ is:

上述方案中，所述根据所述第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值，包括：In the above solution, the obtaining the large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and the preset operation rule includes:

选取所述第二频偏估计值中的两个进行差分运算，根据差分结果按照预设的差分结果与频偏补偿值之间的对应关系对进行差分运算的两个第二频偏估计值分别进行频偏补偿，得到两个待选的大范围频偏估计值。Selecting two of the second frequency offset estimation values to perform a difference operation, and according to the difference result, the two second frequency offset estimation values for performing the difference operation according to the correspondence between the preset difference result and the frequency offset compensation value respectively Perform frequency offset compensation to obtain two large-range frequency offset estimates to be selected.

第二方面，本发明实施例提供了一种频偏估计的装置，所述装置包括：第一估计单元、第二估计单元、第一获取单元及第二获取单元，其中，In a second aspect, an embodiment of the present invention provides a device for estimating a frequency offset, where the device includes: a first estimating unit, a second estimating unit, a first acquiring unit, and a second acquiring unit, where

所述第一估计单元，配置为根据CP的重复性进行频偏估计，获取第一频偏估计值；The first estimating unit is configured to perform frequency offset estimation according to the repeatability of the CP, and obtain a first frequency offset estimation value;

所述第二估计单元，配置为通过预设的导频对获取至少一个第二频偏估计值；The second estimating unit is configured to acquire at least one second frequency offset estimation value by using a preset pilot pair;

所述第一获取单元，配置为根据所述第二估计单元得到的第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；The first obtaining unit is configured to estimate a second frequency offset obtained according to the second estimating unit The value calculation and the preset operation rule obtain the large-range frequency offset estimation value to be selected;

所述第二获取单元，配置为所述第一估计单元得到的第一频偏估计值、所述第一获取单元得到的待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。The second obtaining unit is configured to obtain a first frequency offset estimation value obtained by the first estimating unit, a large range frequency offset estimation value obtained by the first acquiring unit, and a preset range value to obtain an optimal value. The frequency offset estimate.

相应地，所述第二获取单元，配置为：Correspondingly, the second obtaining unit is configured to:

上述方案中，所述第一估计单元，配置为：In the above solution, the first estimating unit is configured to:

以及，根据所述CP序列与所述原始序列的时间差NT_s和所述互相关值cor_CP，按照下式获取第一频偏估计值f_cp：And obtaining, according to the time difference NT _{s of} the CP sequence and the original sequence and the cross-correlation value cor_CP, the first frequency offset estimation value f _cp according to the following formula:

上述方案中，所述第二估计单元，配置为：In the above solution, the second estimating unit is configured to:

将累加后的角度值

其中，f_Δ中的下标Δ表示所述导频对的导频序号差值，

的取值范围是(-π，π)，f_Δ的范围是：

The range of values is (-π, π), and the range of f _Δ is:

上述方案中，所述第一获取单元，配置为：In the above solution, the first acquiring unit is configured to:

第三方面，本发明实施例提供了一种计算机存储介质，所述计算机存储介质包括一组指令，当执行所述指令时，引起至少一个处理器执行上述的频偏估计的方法。In a third aspect, an embodiment of the present invention provides a computer storage medium, the computer storage medium comprising a set of instructions, when executed, causing at least one processor to perform the frequency offset estimation described above.

本发明实施例提供了一种频偏估计的方法、装置和计算机存储介质，通过以CP进行频偏估计值为中心，结合导频符号得到的频偏估计值以及预设的范围进行大范围频偏估计，针对大频偏的问题，不但能够提高频偏估计精度，而且能够避免出现频偏翻转的现象。Embodiments of the present invention provide a method, a device, and a computer storage medium for frequency offset estimation, which perform a large-range frequency by using a frequency offset estimation value of a CP, a frequency offset estimation value obtained by combining pilot symbols, and a preset range. Partial estimation, for the problem of large frequency offset, not only can improve the accuracy of frequency offset estimation, but also avoid the phenomenon of frequency offset.

附图说明DRAWINGS

图1为本发明实施例提供的一种频偏估计的方法流程示意图；1 is a schematic flowchart of a method for estimating frequency offset according to an embodiment of the present invention;

图2为本发明实施例提供的一种OFDM的符号示意图；FIG. 2 is a schematic diagram of a symbol of an OFDM according to an embodiment of the present disclosure;

图3为本发明实施例提供的一种第一区间示意图；FIG. 3 is a schematic diagram of a first interval according to an embodiment of the present disclosure;

图4为本发明实施例提供的一种第二区间示意图；4 is a schematic diagram of a second interval according to an embodiment of the present invention;

图5为本发明实施例提供的一种频偏估计的装置结构示意图。 FIG. 5 is a schematic structural diagram of an apparatus for frequency offset estimation according to an embodiment of the present invention.

具体实施方式detailed description

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述。The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings.

在本发明的各种实施例中：根据CP的重复性进行频偏估计，获取第一频偏估计值；通过预设的导频对获取至少一个第二频偏估计值，并根据第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；根据第一频偏估计值、待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。In various embodiments of the present invention, the frequency offset estimation is performed according to the repeatability of the CP, and the first frequency offset estimation value is obtained; and the at least one second frequency offset estimation value is obtained by using the preset pilot pair, and according to the second frequency. The partial estimation value and the preset operation rule obtain the large-range frequency offset estimation value to be selected; and obtain the optimal frequency offset estimation according to the first frequency offset estimation value, the large-range frequency offset estimation value to be selected, and the preset range value. value.

参见图1，其示出了本发明实施例提供的一种频偏估计的方法，可以应用于根据下行链路状态进行频偏估计的网络设备中，比如移动终端等，该方法可以包括：Referring to FIG. 1 , a method for estimating a frequency offset according to an embodiment of the present invention may be applied to a network device that performs frequency offset estimation according to a downlink state, such as a mobile terminal, and the method may include:

S101：根据CP的重复性进行频偏估计，获取第一频偏估计值；S101: Perform frequency offset estimation according to repeatability of the CP, and obtain a first frequency offset estimation value;

示例性地，在本实施例中，步骤S101具体可以包括：Illustratively, in this embodiment, step S101 may specifically include:

首先，获取CP序列及与CP序列相同的原始序列的互相关值cor_CP；First, obtaining a cross-correlation value cor_CP of the CP sequence and the original sequence identical to the CP sequence;

接着，根据CP序列与原始序列的时间差NT_s和互相关值cor_CP，按照式(1)获取第一频偏估计值f_cp：Then, according to the time difference NT _{s of the} CP sequence and the original sequence and the cross-correlation value cor_CP, the first frequency offset estimation value f _{cp is} obtained according to the formula (1):

需要说明的是，如图2所示，在OFDM符号的保护间隔内填入的CP序列与OFDM符号的尾端序列数据相同，因此，以图2中的阴影所示，OFDM符号的尾端序列为CP序列的原始序列，由于两个序列的数据相同，因此即使经过了多径信道的传输，CP序列以及原始序列之间就保存了信道的时移和频移信息，可以通过CP序列以及原始序列的互相关值cor_CP得到；It should be noted that, as shown in FIG. 2, the CP sequence filled in the guard interval of the OFDM symbol is the same as the tail sequence data of the OFDM symbol, and therefore, the tail sequence of the OFDM symbol is shown by the hatching in FIG. 2. As the original sequence of the CP sequence, since the data of the two sequences are the same, even after the transmission of the multipath channel, the time shift and frequency shift information of the channel are preserved between the CP sequence and the original sequence, and the CP sequence and the original can be obtained. The cross-correlation value of the sequence is obtained by cor_CP;

具体地，CP序列以及原始序列的互相关值cor_CP的计算过程具体可以是

其中，conj(·)表示对复数向量·进行共轭运算，n表示对OFDM符号进行采样的采样点，N表示两个序列之间采样点的序号差，d(n)为原始序列，d′(n)为CP序列，且d′(n)＝d(n)*exp(j*2π*Δf*NT_s)，其中，Δf为频偏，NT_s为两个序列之间的时间差。Specifically, the calculation process of the CP sequence and the cross-correlation value cor_CP of the original sequence may specifically be

Where conj(·) indicates that the complex vector is conjugated, n represents the sampling point for sampling the OFDM symbol, N represents the sequence number difference between the two sequences, d(n) is the original sequence, d' (n) is a CP sequence, and d'(n)=d(n)*exp(j*2π*Δf*NT _s ), where Δf is the frequency offset and NT _s is the time difference between the two sequences.

S102：通过预设的导频对获取至少一个第二频偏估计值，并根据第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；S102: Acquire at least one second frequency offset estimation value by using a preset pilot pair, and obtain a large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and a preset operation rule.

示例性地，通过预设的导频对获取至少一个第二频偏估计值，具体可以包括：Illustratively, obtaining the at least one second frequency offset estimation value by using the preset pilot pair may specifically include:

首先，将导频对的符号进行共轭相乘之后，再将相乘的结果进行累加，获取累加后的角度值

First, after the symbols of the pilot pairs are conjugate multiplied, the multiplied results are accumulated to obtain the accumulated angle values.

然后，将累加后的角度值

以及导频对的符号之间的时间差Δt，按照下式获取第二频偏估计值f_Δ：Then, the angle value after the accumulation

And the time difference Δt between the symbols of the pilot pair, and obtaining the second frequency offset estimated value f _Δ according to the following formula:

其中，f_Δ中的下标Δ表示导频对的导频序号差值，

的取值范围是(-π，π)，f_Δ的范围是：

Wherein, the subscript _Δ in f _Δ represents the pilot sequence difference value of the pilot pair,

The range of values is (-π, π), and the range of f _Δ is:

在本实施例中，以CRS的导频符号为例进行说明，在长期演进(LTE，Long Term Evolution)***的下行协议中，规定了CRS中序号为0、4、7、11的导频符号用来进行频偏估计，因此，这四个导频符号可以得到

个导频对，分别是导频序号为4和7、0和4、7和11、0和7、4和11以及0和11这6个导频对，按照上述的过程对这六个导频对进行处理，分别得到六个第二频偏估计值，分别是f₃、f_4a、f_4b、f_7a、f_7b和f₁₁，可以理解的，由于0和4、7和11导频对的导频序号差值均为4，0和7、4和11导频对的导频序号差值均为7，因此，在第二频偏估计值中，差值相同的不同导频对所得到的第二频偏估计值以下标a，b进行区分。In this embodiment, the pilot symbol of the CRS is taken as an example. In the downlink protocol of the Long Term Evolution (LTE) system, pilot symbols with numbers 0, 4, 7, and 11 in the CRS are specified. Used to perform frequency offset estimation, therefore, these four pilot symbols can be obtained

Pilot pairs, which are 6 pilot pairs of pilot numbers 4 and 7, 0 and 4, 7 and 11, 0 and 7, 4 and 11, and 0 and 11, respectively, according to the above process. The frequency pairs are processed to obtain six second frequency offset estimates, namely f ₃ , f _4a , f _4b , f _7a , f _7b and f ₁₁ , respectively, as can be understood, since 0 and 4, 7 and 11 pilots The pilot sequence number difference is 4, and the pilot sequence number difference of the 4, 4, and 11 pilot pairs is 7, therefore, in the second frequency offset estimation, the different pilot pairs with the same difference The obtained second frequency offset estimation value is distinguished by the following a, b.

示例性地，根据第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值，具体可以包括：Illustratively, the obtaining the large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and the preset operation rule may specifically include:

选取第二频偏估计值中的两个进行差分运算，根据差分结果按照预设的差分结果与频偏补偿值之间的对应关系对进行差分运算的两个第二频偏估计值分别进行频偏补偿，得到两个待选的大范围频偏估计值。Selecting two of the second frequency offset estimation values to perform a difference operation, and respectively performing frequency difference between the two second frequency offset estimation values for performing the difference operation according to the correspondence between the preset difference result and the frequency offset compensation value according to the difference result Offset compensation, get two large range of frequency offset estimates to be selected.

具体地，以前述的六个第二频偏估计值为例进行说明，当得到六个第二频偏估计值，分别是f₃、f_4a、f_4b、f_7a、f_7b和f₁₁之后，可以从这六个第二频偏估计值中两两进行差分运算，从而能够得到

个差分结果，根据15个差分结果可以得到最多

个待选的大范围频偏估计值；需要说明的是，在实际应用中，由于频偏范围过小，例如序号0和11导频对所得到的频偏估计的范围过小，M的数量通常会小于30；Specifically, the foregoing six second frequency offset estimation values are used as an example. When six second frequency offset estimation values are obtained, respectively, f ₃ , f _4a , f _4b , f _7a , f _{7b ,} and f ₁₁ , can perform differential operation from two of the six second frequency offset estimates, thereby obtaining

Difference results, up to 15 differential results

A large range of frequency offset estimates to be selected; it should be noted that, in practical applications, since the frequency offset range is too small, for example, the range of the frequency offset estimates obtained by the pilot numbers 0 and 11 is too small, and the number of M is too small. Usually less than 30;

以f₃和f_4a进行差分运算并得到待选的大范围频偏估计值为例，假定f_4a-f₃的结果为3.5kHz，那么，预设的3.5kHz所对应的f₃的频偏补偿值为0，f_4a的频偏补偿值为-1.75k×2，于是，分别按照频偏补偿值对f₃和f_4a进行补偿后，得到的待选的大范围频偏估计值为f₃以及f_4a-1.75k×2。Taking the differential operation of f ₃ and f _4a and obtaining the large-range frequency offset estimation value to be selected, assuming that the result of f _4a -f ₃ is 3.5 kHz, then the preset frequency offset of f ₃ corresponding to 3.5 kHz The compensation value is 0, and the frequency offset compensation value of f _4a is -1.75k×2. Then, after f ₃ and f _4a are compensated according to the frequency offset compensation value, the obtained large-range frequency offset estimation value is f. ₃ and f _{4a -} 1.75k × 2.

S103：根据第一频偏估计值、待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。S103: Acquire an optimal frequency offset estimation value according to the first frequency offset estimation value, the to-be selected large-range frequency offset estimation value, and the preset range value.

示例性地，预设的范围值包括预设的第一范围值和预设的第二范围值，且第一范围值小于第二范围值；Exemplarily, the preset range value includes a preset first range value and a preset second range value, and the first range value is smaller than the second range value;

相应地，步骤S103具体可以包括：Correspondingly, step S103 may specifically include:

当待选的大范围频偏估计值均处于以第一频偏估计值为中心，以第一范围值为长度的第一区间内时，最优的频偏估计值为待选的大范围频偏估计值的平均值；When the large-range frequency offset estimation values to be selected are all in the first interval with the first frequency offset estimation value and the first range value is the length, the optimal frequency offset estimation value is the large-range frequency to be selected. The average of the partial estimates;

当待选的大范围频偏估计值中的至少一个处于第二区间时，最优的频偏估计值为但处于第二区间的待选的大范围频偏估计值的平均值；其中，第二区间为以第一频偏估计值为中心，以第二范围值为长度的区间减去第一区间后得到的区间；When at least one of the large range frequency offset estimates to be selected is in the second interval, the optimal frequency The partial estimated value is the average of the large-range frequency offset estimation values of the candidate in the second interval; wherein the second interval is the first frequency offset estimation value, and the second range value is the length interval minus The interval obtained after the first interval;

当待选的大范围频偏估计值均不处于第一区间和第二区间时，最优的频偏估计值为第一频偏估计值。When the large-range frequency offset estimation values to be selected are not in the first interval and the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.

具体地，预设的范围值通常是根据以往的经验数据所设定的，在本实施例中，第一范围值T₁可以预设为200Hz，第二范围值T₂可以预设为2kHz，那么，以步骤S102所得到的待选的大范围频偏估计值为例，待选的大范围频偏估计值为

其中M为待选的大范围频偏估计值的个数，以第一频偏估计值f_cp为中心，通过第一范围值和第二范围值对

进行筛除，从而最后得到最优的频偏估计值，具体过程为：Specifically, the preset range value is generally set according to the previous experience data. In this embodiment, the first range value T ₁ may be preset to 200 Hz, and the second range value T ₂ may be preset to 2 kHz. Then, taking the large-range frequency offset estimation value to be selected obtained in step S102 as an example, the large-range frequency offset estimation value to be selected is

Where M is the number of large-range frequency offset estimates to be selected, centered on the first frequency offset estimate f _cp , and passes the first range value and the second range value pair

Screening is performed to obtain the optimal frequency offset estimate. The specific process is as follows:

若所有的

都满足

则最优的频偏估计值

可以理解的，本实施例中，如图3所示，以第一频偏估计值f_cp为中心，以第一范围值T₁为长度设置第一区间，如图3中的粗实心直线区域所示，当所有的

都处于第一区间时，最优的频偏估计值为所有的

的平均值；If all

All satisfied

Optimal frequency offset estimate

It can be understood that, in this embodiment, as shown in FIG. 3, the first interval is set with the first range value T ₁ as the center, and the thick solid straight region in FIG. 3 is taken as the center of the first frequency offset estimation value f _{cp .} As shown, when all

When both are in the first interval, the optimal frequency offset estimates are all

average value;

若存在

满足

则将满足

的

中获取同时满足

来组成集合

那么此时最优的频偏估计值

其中，N为集合

中的元素个数；可以理解的，当

中存在处于以第一频偏估计值f_cp为中心，以第二范围值T₁为长度的区间减去第一区间后得到的第二区间，如图4所示的粗实心直线区域所示，当存在

处于第二区间时，最优的频偏估计值为处于第二区间的

的平均值；If it exists

Satisfy

Will satisfy

of

Acquisition while satisfying

To form a collection

Then the optimal frequency offset estimate at this time

Where N is a collection

The number of elements in the; understandable, when

There is a second interval obtained by subtracting the first interval from the interval with the first frequency offset estimated value f _cp as the center and the second range value T ₁ as the length, as shown by the thick solid straight line region shown in FIG. 4 . When there is

In the second interval, the optimal frequency offset estimate is in the second interval.

average value;

其他情况，即所有的

均满足

那么最优的频偏估计值Δf＝f_cp，可以理解的，当所有的

即不处于第一区间，也不处于第二区间时，最优的频偏估计值为第一频偏估计值。Other situations, that is, all

All satisfied

Then the optimal frequency offset estimate Δf=f _cp , understandable, when all

That is, when not in the first interval and not in the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.

本实施例提供了一种频偏估计的方法，通过以CP进行频偏估计值为中心，结合导频符号得到的频偏估计值以及预设的范围进行大范围频偏估计，针对大频偏的问题，不但能够提高频偏估计精度，而且能够避免出现频偏翻转的现象。This embodiment provides a frequency offset estimation method, which performs large-scale frequency offset estimation by using a frequency offset estimation value of a CP, a frequency offset estimation value obtained by combining pilot symbols, and a preset range, and is directed to a large frequency offset. The problem can not only improve the accuracy of the frequency offset estimation, but also avoid the phenomenon of frequency offset.

结合前述实施例相同的技术构思，参见图5，其示出了本发明实施例提供的一种频偏估计的装置50，该装置50可以应用于根据下行链路状态进行频偏估计的网络设备中，该装置50可以包括：第一估计单元501、第二估计单元502、第一获取单元503及第二获取单元504，其中，With reference to FIG. 5, which shows a device 50 for frequency offset estimation according to an embodiment of the present invention, the device 50 can be applied to a network device for performing frequency offset estimation according to a downlink state. The device 50 may include: a first estimating unit 501, a second estimating unit 502, a first obtaining unit 503, and a second acquiring unit 504, where

第一估计单元501，配置为根据CP的重复性进行频偏估计，获取第一频偏估计值；The first estimating unit 501 is configured to perform frequency offset estimation according to the repeatability of the CP, and obtain a first frequency offset estimation value;

第二估计单元502，配置为通过预设的导频对获取至少一个第二频偏估计值；The second estimating unit 502 is configured to acquire at least one second frequency offset estimation value by using a preset pilot pair;

第一获取单元503，配置为根据第二估计单元502得到的第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；The first obtaining unit 503 is configured to obtain a large-range frequency offset estimation value to be selected according to the second frequency offset estimation value obtained by the second estimating unit 502 and a preset operation rule;

第二获取单元504，配置为根据第一估计单元501得到的第一频偏估计值、第一获取单元503得到的待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。The second obtaining unit 504 is configured to obtain an optimal frequency according to the first frequency offset estimation value obtained by the first estimating unit 501, the large-range frequency offset estimation value to be selected by the first acquiring unit 503, and the preset range value. Partial estimate.

在一实施例中，预设的范围值包括预设的第一范围值和预设的第二范围值，且第一范围值小于第二范围值；In an embodiment, the preset range value includes a preset first range value and a preset second range value, and the first range value is smaller than the second range value;

相应地，第二获取单元504，具体配置为：Correspondingly, the second obtaining unit 504 is specifically configured to:

以及，当待选的大范围频偏估计值中的至少一个处于第二区间时，最优的频偏估计值为但处于第二区间的待选的大范围频偏估计值的平均值；其中，第二区间为以第一频偏估计值为中心，以第二范围值为长度的区间减去第一区间后得到的区间；And when at least one of the large range frequency offset estimates to be selected is in the second interval, the most The preferred frequency offset estimation value is an average value of the to-be selected large-range frequency offset estimation values in the second interval; wherein, the second interval is centered on the first frequency offset estimation value, and the second range value is in length The interval obtained by subtracting the first interval from the interval;

以及，当待选的大范围频偏估计值均不处于第一区间和第二区间时，最优的频偏估计值为第一频偏估计值。And, when the large-range frequency offset estimation values to be selected are not in the first interval and the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.

在一实施例中，第一估计单元501，具体配置为：In an embodiment, the first estimating unit 501 is specifically configured to:

获取CP序列及与CP序列相同的原始序列的互相关值cor_CP；Obtaining a cross-correlation value cor_CP of the CP sequence and the original sequence identical to the CP sequence;

以及，根据CP序列与原始序列的时间差NT_s和互相关值cor_CP，按照下式获取第一频偏估计值f_cp：And, according to the time difference NT _{s of the} CP sequence and the original sequence and the cross-correlation value cor_CP, the first frequency offset estimation value f _{cp is} obtained according to the following formula:

在一实施例中，第二估计单元502，具体配置为：In an embodiment, the second estimating unit 502 is specifically configured to:

将导频对的符号进行共轭相乘之后，再将相乘的结果进行累加，获取累加后的角度值

After the symbols of the pilot pairs are multiplied by conjugate, the multiplied results are accumulated to obtain the accumulated angle values.

将累加后的角度值

以及导频对的符号之间的时间差Δt，按照下式获取第二频偏估计值f_Δ：The angle value after the accumulation

其中，f_Δ中的下标Δ表示导频对的导频序号差值，

的取值范围是(-π，π)，f_Δ的范围是：

The range of values is (-π, π), and the range of f _Δ is:

在一实施例中，第一获取单元503，具体配置为：In an embodiment, the first obtaining unit 503 is specifically configured to:

实际应用时，第一估计单元501、第二估计单元502、第一获取单元503 及第二获取单元504可由频偏估计的装置50中的中央处理器(CPU，Central Processing Unit)、微处理器(MCU，Micro Control Unit)、数字信号处理器(DSP，Digital Signal Processor)或可编程逻辑阵列(FPGA，Field-Programmable Gate Array)实现。In actual application, the first estimating unit 501, the second estimating unit 502, and the first acquiring unit 503 And the second obtaining unit 504 can be a CPU (Central Processing Unit), a Microprocessor Unit (MCU), a Digital Signal Processor (DSP), or the like. Field-Programmable Gate Array (FPGA) implementation.

本实施例提供了一种频偏估计的装置50，通过以CP进行频偏估计值为中心，结合导频符号得到的频偏估计值以及预设的范围进行大范围频偏估计，针对大频偏的问题，不但能够提高频偏估计精度，而且能够避免出现频偏翻转的现象。The present embodiment provides a frequency offset estimation apparatus 50, which performs large-scale frequency offset estimation by using a frequency offset estimation value of a CP, a frequency offset estimation value obtained by combining pilot symbols, and a preset range, and is configured for a large frequency. The problem of partial bias can not only improve the accuracy of frequency offset estimation, but also avoid the phenomenon of frequency offset.

本领域内的技术人员应明白，本发明的实施例可提供为方法、***、或计算机程序产品。因此，本发明可采用硬件实施例、软件实施例、或结合软件和硬件方面的实施例的形式。而且，本发明可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器和光学存储器等)上实施的计算机程序产品的形式。Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention can take the form of a hardware embodiment, a software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) including computer usable program code.

本发明是参照根据本发明实施例的方法、设备(***)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。 The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

基于此，本发明实施例还提供了一种计算机存储介质，所述计算机存储介质包括一组指令，当执行所述指令时，引起至少一个处理器执行上述的频偏估计的方法。Based on this, an embodiment of the present invention further provides a computer storage medium, the computer storage medium comprising a set of instructions, when the instruction is executed, causing at least one processor to perform the frequency offset estimation method.

以上，仅为本发明的较佳实施例而已，并非用于限定本发明的保护范围。 The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

一种频偏估计的方法，所述方法包括：A method for frequency offset estimation, the method comprising:

根据循环前缀CP的重复性进行频偏估计，获取第一频偏估计值；Performing a frequency offset estimation according to the repeatability of the cyclic prefix CP to obtain a first frequency offset estimation value;

通过预设的导频对获取至少一个第二频偏估计值，并根据所述第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值；Acquiring at least one second frequency offset estimation value by using a preset pilot pair, and obtaining a large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and a preset operation rule;

根据所述第一频偏估计值、所述待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。And obtaining an optimal frequency offset estimation value according to the first frequency offset estimation value, the to-be selected large-range frequency offset estimation value, and a preset range value.
根据权利要求1所述的方法，其中，所述预设的范围值包括预设的第一范围值和预设的第二范围值，且所述第一范围值小于所述第二范围值；The method according to claim 1, wherein the preset range value comprises a preset first range value and a preset second range value, and the first range value is smaller than the second range value;

相应地，根据所述第一频偏估计值、所述待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值，包括：Correspondingly, obtaining an optimal frequency offset estimation value according to the first frequency offset estimation value, the to-be selected large-range frequency offset estimation value, and a preset range value, including:

当所述待选的大范围频偏估计值均处于以所述第一频偏估计值为中心，以所述第一范围值为长度的第一区间内时，所述最优的频偏估计值为所述待选的大范围频偏估计值的平均值；或者，The optimal frequency offset estimation is performed when the to-be selected large-range frequency offset estimation values are all within the first interval with the first frequency offset estimation value and the first range value is the length. a value that is an average of the large range of frequency offset estimates to be selected; or,

当所述待选的大范围频偏估计值中的至少一个处于第二区间时，所述最优的频偏估计值为但处于第二区间的待选的大范围频偏估计值的平均值；其中，所述第二区间为以所述第一频偏估计值为中心，以所述第二范围值为长度的区间减去所述第一区间后得到的区间；或者，When at least one of the to-be selected large-range frequency offset estimation values is in the second interval, the optimal frequency offset estimation value is an average value of the to-be-selected large-range frequency offset estimation values in the second interval. Wherein the second interval is an interval obtained by subtracting the first interval from an interval in which the second range value is the center and the second range value is a length; or

当所述待选的大范围频偏估计值均不处于所述第一区间和所述第二区间时，所述最优的频偏估计值为所述第一频偏估计值。And when the to-be selected large-range frequency offset estimation values are not in the first interval and the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.
根据权利要求1所述的方法，其中，所述根据CP的重复性进行频偏估计，获取第一频偏估计值，包括：The method according to claim 1, wherein the performing the frequency offset estimation according to the repeatability of the CP to obtain the first frequency offset estimation value comprises:

获取CP序列及与所述CP序列相同的原始序列的互相关值cor_CP；Obtaining a cross-correlation value cor_CP of the CP sequence and the original sequence identical to the CP sequence;

根据所述CP序列与所述原始序列的时间差NTs和所述互相关值cor_CP，按照下式获取第一频偏估计值f_cp： Obtaining the first frequency offset estimation value f _cp according to the following equation according to the time difference NTs of the CP sequence and the original sequence and the cross-correlation value cor_CP:

其中，angle(·)表示复数向量·和实轴正方向的夹角。Where angle(·) represents the angle between the complex vector and the positive direction of the real axis.
根据权利要求1所述的方法，其中，所述通过预设的导频对获取至少一个第二频偏估计值，包括：The method of claim 1, wherein the obtaining the at least one second frequency offset estimate by using the preset pilot pair comprises:

将所述导频对的符号进行共轭相乘之后，再将相乘的结果进行累加，获取累加后的角度值
After conjugate multiplying the symbols of the pilot pair, the multiplied results are accumulated to obtain the accumulated angle values.

将累加后的角度值
以及导频对的符号之间的时间差Δt，按照下式获取所述第二频偏估计值f_Δ：The angle value after the accumulation
And the time difference Δt between the symbols of the pilot pair, the second frequency offset estimated value f _{Δ is} obtained according to the following formula:

其中，f_Δ中的下标Δ表示所述导频对的导频序号差值，
的取值范围是(-π,π)，f_Δ的范围是：
Wherein the subscript _Δ in f _Δ represents the pilot sequence difference value of the pilot pair,
The range of values is (-π, π), and the range of f _Δ is:
根据权利要求1所述的方法，其中，所述根据所述第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值，包括：The method according to claim 1, wherein the obtaining the large-range frequency offset estimation value to be selected according to the second frequency offset estimation value and a preset operation rule comprises:

选取所述第二频偏估计值中的两个进行差分运算，根据差分结果按照预设的差分结果与频偏补偿值之间的对应关系对进行差分运算的两个第二频偏估计值分别进行频偏补偿，得到两个待选的大范围频偏估计值。Selecting two of the second frequency offset estimation values to perform a difference operation, and according to the difference result, the two second frequency offset estimation values for performing the difference operation according to the correspondence between the preset difference result and the frequency offset compensation value respectively Perform frequency offset compensation to obtain two large-range frequency offset estimates to be selected.
一种频偏估计的装置，所述装置包括：第一估计单元、第二估计单元、第一获取单元及第二获取单元，其中，A device for estimating a frequency offset, the device comprising: a first estimating unit, a second estimating unit, a first acquiring unit, and a second acquiring unit, wherein

所述第一估计单元，配置为根据CP的重复性进行频偏估计，获取第一频偏估计值；The first estimating unit is configured to perform frequency offset estimation according to the repeatability of the CP, and obtain a first frequency offset estimation value;

所述第二估计单元，配置为通过预设的导频对获取至少一个第二频偏估计值；The second estimating unit is configured to acquire at least one second frequency offset estimation value by using a preset pilot pair;

所述第一获取单元，配置为根据所述第二估计单元得到的第二频偏估计值和预设的运算规则获取待选的大范围频偏估计值； The first acquiring unit is configured to obtain a large-range frequency offset estimation value to be selected according to the second frequency offset estimation value obtained by the second estimating unit and a preset operation rule;

所述第二获取单元，配置为所述第一估计单元得到的第一频偏估计值、所述第一获取单元得到的待选的大范围频偏估计值以及预设的范围值获取最优的频偏估计值。The second obtaining unit is configured to obtain a first frequency offset estimation value obtained by the first estimating unit, a large range frequency offset estimation value obtained by the first acquiring unit, and a preset range value to obtain an optimal value. The frequency offset estimate.
根据权利要求6所述的装置，其中，所述预设的范围值包括预设的第一范围值和预设的第二范围值，且所述第一范围值小于所述第二范围值；The device according to claim 6, wherein the preset range value comprises a preset first range value and a preset second range value, and the first range value is smaller than the second range value;

相应地，所述第二获取单元，配置为：Correspondingly, the second obtaining unit is configured to:

当所述待选的大范围频偏估计值均处于以所述第一频偏估计值为中心，以所述第一范围值为长度的第一区间内时，所述最优的频偏估计值为所述待选的大范围频偏估计值的平均值；或者，The optimal frequency offset estimation is performed when the to-be selected large-range frequency offset estimation values are all within the first interval with the first frequency offset estimation value and the first range value is the length. a value that is an average of the large range of frequency offset estimates to be selected; or,

当所述待选的大范围频偏估计值中的至少一个处于第二区间时，所述最优的频偏估计值为但处于第二区间的待选的大范围频偏估计值的平均值；其中，所述第二区间为以所述第一频偏估计值为中心，以所述第二范围值为长度的区间减去所述第一区间后得到的区间；或者，When at least one of the to-be selected large-range frequency offset estimation values is in the second interval, the optimal frequency offset estimation value is an average value of the to-be-selected large-range frequency offset estimation values in the second interval. Wherein the second interval is an interval obtained by subtracting the first interval from an interval in which the second range value is the center and the second range value is a length; or

当所述待选的大范围频偏估计值均不处于所述第一区间和所述第二区间时，所述最优的频偏估计值为所述第一频偏估计值。And when the to-be selected large-range frequency offset estimation values are not in the first interval and the second interval, the optimal frequency offset estimation value is the first frequency offset estimation value.
根据权利要求6所述的装置，其中，所述第一估计单元，配置为：The apparatus according to claim 6, wherein the first estimating unit is configured to:

获取CP序列及与所述CP序列相同的原始序列的互相关值cor_CP；Obtaining a cross-correlation value cor_CP of the CP sequence and the original sequence identical to the CP sequence;

以及，根据所述CP序列与所述原始序列的时间差NT_s和所述互相关值cor_CP，按照下式获取第一频偏估计值f_cp：And obtaining, according to the time difference NT _{s of} the CP sequence and the original sequence and the cross-correlation value cor_CP, the first frequency offset estimation value f _cp according to the following formula:

其中，angle(·)表示复数向量·和实轴正方向的夹角。Where angle(·) represents the angle between the complex vector and the positive direction of the real axis.
根据权利要求6所述的装置，其中，所述第二估计单元，配置为：The apparatus according to claim 6, wherein the second estimating unit is configured to:

将所述导频对的符号进行共轭相乘之后，再将相乘的结果进行累加，获取累加后的角度值
After conjugate multiplying the symbols of the pilot pair, the multiplied results are accumulated to obtain the accumulated angle values.

将累加后的角度值
以及导频对的符号之间的时间差Δt，按照下式获取所述第二频偏估计值f_Δ：The angle value after the accumulation
And the time difference Δt between the symbols of the pilot pair, the second frequency offset estimate f _{Δ is} obtained according to the following equation:

其中，f_Δ中的下标Δ表示所述导频对的导频序号差值，
的取值范围是(-π,π)，f_Δ的范围是：
Wherein the subscript _Δ in f _Δ represents the pilot sequence difference value of the pilot pair,
The range of values is (-π, π), and the range of f _Δ is:
根据权利要求6所述的装置，其中，所述第一获取单元，配置为：The device according to claim 6, wherein the first obtaining unit is configured to:

选取所述第二频偏估计值中的两个进行差分运算，根据差分结果按照预设的差分结果与频偏补偿值之间的对应关系对进行差分运算的两个第二频偏估计值分别进行频偏补偿，得到两个待选的大范围频偏估计值。Selecting two of the second frequency offset estimation values to perform a difference operation, and according to the difference result, the two second frequency offset estimation values for performing the difference operation according to the correspondence between the preset difference result and the frequency offset compensation value respectively Perform frequency offset compensation to obtain two large-range frequency offset estimates to be selected.
一种计算机存储介质，所述计算机存储介质包括一组指令，当执行所述指令时，引起至少一个处理器执行如权利要求1至5任一项所述的频偏估计的方法。 A computer storage medium comprising a set of instructions that, when executed, cause at least one processor to perform the method of frequency offset estimation according to any one of claims 1 to 5.