CN102938751A - Method and device for windowing time domains of time domain synchronization orthogonal frequency division multiplexing system - Google Patents

Method and device for windowing time domains of time domain synchronization orthogonal frequency division multiplexing system Download PDF

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CN102938751A
CN102938751A CN2012104609433A CN201210460943A CN102938751A CN 102938751 A CN102938751 A CN 102938751A CN 2012104609433 A CN2012104609433 A CN 2012104609433A CN 201210460943 A CN201210460943 A CN 201210460943A CN 102938751 A CN102938751 A CN 102938751A
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杨昉
潘长勇
丁文伯
阳辉
宋健
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Tsinghua University
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Abstract

本发明公开了一种时域同步正交频分复用系统的时域加窗方法及装置,该方法包括:根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;生成本帧的循环后缀,并复制到本帧数据块之后;对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。本发明实现过程简单、复杂度低,在指定频段内提高传输速率的同时,还可提高信号传输的灵活性、有效性及可靠性,提升频谱效率。

The invention discloses a time-domain windowing method and device for a time-domain synchronous OFDM system. The method includes: combining the training sequence with the corresponding inverse discrete Fourier transform data block according to the system transmission parameters Generate a time-domain synchronous OFDM system signal frame, define the current frame as this frame, and define its previous and subsequent signal frames as the previous frame and subsequent frame in turn; generate the cyclic suffix of this frame and copy it to the data of this frame After the block; W/2 symbols before the training sequence of this frame and the W/2 symbols of the cyclic suffix are subjected to time-domain windowing processing, wherein W is the window length; The W/2 symbols are sequentially added in the time domain to the W/2 symbols of the cyclic suffix of the previous frame after the windowing process in the time domain. The implementation process of the invention is simple and the complexity is low. While increasing the transmission rate in the designated frequency band, the invention can also improve the flexibility, effectiveness and reliability of signal transmission, and improve the spectrum efficiency.

Description

时域同步正交频分复用系统的时域加窗方法及装置Time Domain Windowing Method and Device for Time Domain Synchronous Orthogonal Frequency Division Multiplexing System

技术领域technical field

本发明涉及数字信号传输技术领域,特别涉及一种时域同步正交频分复用(Time Domain Synchronous OFDM,TDS-OFDM)系统的时域加窗方法及其装置。The present invention relates to the technical field of digital signal transmission, in particular to a time domain windowing method and a device thereof for a time domain synchronous orthogonal frequency division multiplexing (Time Domain Synchronous OFDM, TDS-OFDM) system.

背景技术Background technique

目前宽带无线通信技术主要解决的问题是如何在有限的带宽内可靠地提高传输速率,对于有限的频谱资源需要进一步提升频谱效率,LTE-A的标准化中明确提出了上、下行链路频谱效率分别为15bit/Hz和30bit/Hz的要求。正交频分复用(OFDM:Orthogonal FrequencyDivision Multiplexing)技术由于高频谱效率和对抗多径衰落的优异能力而广泛受到应用,被认为是当前最有前景的传输技术之一。At present, the main problem to be solved by broadband wireless communication technology is how to reliably increase the transmission rate within a limited bandwidth. For limited spectrum resources, it is necessary to further improve the spectrum efficiency. Requirements for 15bit/Hz and 30bit/Hz. Orthogonal Frequency Division Multiplexing (OFDM: Orthogonal Frequency Division Multiplexing) technology is widely used due to its high spectral efficiency and excellent ability to resist multipath fading, and is considered to be one of the most promising transmission technologies at present.

然而,对于块传输系统而言,虽然数据块的持续时间远远大于单个符号的持续时间,但是在大的延时扩展通道下,时域数据块之间仍然存在不可忽略的IBI(Inter Block Interference,块间干扰)。现有技术中块传输系统对抗IBI的一种有效方法是在时域数据块之间加入GI(Guard Interval,保护间隔),通道的最大多径延时不超过GI长度的情况下,时域数据块之间不会产生干扰。根据GI填充内容的不同种类,存在着多种GI填充技术,其中包括CP(Cyclic Prefix,循环前缀)填充技术,ZP(Zero Padding,零填充)技术,和TS(Training Sequence,训练序列)填充技术等等。其中CP填充技术已经成功应用到IEEE802.11a无线局域网、地面数位视频广播(Digital VideoBroadcasting-Terrestrial,DVB-T)及其第二代标准DVB-T2系统和IEEE1901和G.hn宽带电力线通信系统中,其帧结构如图1所示;基于PN(Pseudo-random Noise,伪随机噪声)序列填充的方法是TS填充技术的特例,属于TDS-OFDM系统的一个重要特征,该技术已成功应用到中国地面数字电视传输标准(Digital Television Multimedia Broadcast,DTMB)中,其帧结构如图2所示。However, for a block transmission system, although the duration of a data block is much longer than the duration of a single symbol, there is still a non-negligible IBI (Inter Block Interference) between time domain data blocks under a large delay extension channel. , inter-block interference). An effective method for the block transmission system in the prior art to resist IBI is to add GI (Guard Interval, Guard Interval) between time domain data blocks. When the maximum multipath delay of the channel does not exceed the length of GI, the time domain data There is no interference between blocks. According to different types of GI filling content, there are a variety of GI filling technologies, including CP (Cyclic Prefix, cyclic prefix) filling technology, ZP (Zero Padding, zero filling) technology, and TS (Training Sequence, training sequence) filling technology etc. Among them, CP filling technology has been successfully applied to IEEE802.11a wireless local area network, terrestrial digital video broadcasting (Digital Video Broadcasting-Terrestrial, DVB-T) and its second generation standard DVB-T2 system and IEEE1901 and G.hn broadband power line communication system, Its frame structure is shown in Figure 1; the method based on PN (Pseudo-random Noise, pseudorandom noise) sequence filling is a special case of TS filling technology, which belongs to an important feature of the TDS-OFDM system. This technology has been successfully applied to the ground in China In the digital television transmission standard (Digital Television Multimedia Broadcast, DTMB), its frame structure is shown in Figure 2.

在宽带通信中,有一些频段是为业余无线电、远程控制以及宇航通信等服务预留的,因此不能受到较强的电磁辐射干扰;然而某些依赖传输介质的通信,比如PLC(Power Line Communication,电力线通信)无法做到完全对外界屏蔽,会有一些信号耦合出去;为了减少耦合的信号对上述重要服务产生干扰,一般会对预留频段进行陷波处理。在基于OFDM的传输系统中,一般有两种常见的陷波方法:第一种是发送完整的OFDM符号,依靠陷波滤波器(Notched Filter,可以使用IIR或FIR实现),但是固定参数的陷波滤波器不能很好的适应环境多变、不确定性较强的情况,比如PLC的通信环境。第二种是直接关闭OFDM中相应频段周围的部分子载波,但是此时需要让子载波在频域快速滚降以尽可能降低干扰,同时提高系统频谱利用率。In broadband communication, some frequency bands are reserved for services such as amateur radio, remote control, and aerospace communication, so they cannot be interfered by strong electromagnetic radiation; however, some communications that rely on transmission media, such as PLC (Power Line Communication, Power line communication) cannot be completely shielded from the outside world, and some signals will be coupled out; in order to reduce the interference of the coupled signals to the above-mentioned important services, the reserved frequency band is generally notched. In an OFDM-based transmission system, there are generally two common notch methods: the first is to send a complete OFDM symbol, relying on a notched filter (Notched Filter, which can be implemented using IIR or FIR), but the fixed parameter notch The wave filter cannot be well adapted to the situation where the environment is changeable and the uncertainty is strong, such as the communication environment of PLC. The second is to directly turn off some subcarriers around the corresponding frequency band in OFDM, but at this time, the subcarriers need to be rolled off quickly in the frequency domain to reduce interference as much as possible and improve system spectrum utilization.

经研究表明,在时域配合适当的加窗处理,可以让OFDM的子载波在频域快速滚降,同时有效的降低子载波旁瓣,提高系统的频谱效率。因此,对基于TDS-OFDM帧结构的数字通信传输系统,有必要通过合理的帧结构设计、合适的加窗处理来提高信号传输的灵活性、有效性以及可靠性,进一步提升频谱效率,减少特定频段上传输信号对外界的干扰。Studies have shown that with proper windowing in the time domain, OFDM subcarriers can roll off rapidly in the frequency domain, while effectively reducing subcarrier sidelobes and improving the spectral efficiency of the system. Therefore, for a digital communication transmission system based on TDS-OFDM frame structure, it is necessary to improve the flexibility, effectiveness and reliability of signal transmission through reasonable frame structure design and appropriate windowing processing, further improve spectrum efficiency, and reduce specific The interference of the transmission signal on the frequency band to the outside world.

发明内容Contents of the invention

(一)要解决的技术问题(1) Technical problems to be solved

本发明目的在于提供一种基于时域同步正交频分复用(TimeDomain Synchronous OFDM,TDS-OFDM)系统的时域加窗方法及装置,以提高系统的频谱效率。The purpose of the present invention is to provide a time domain windowing method and device based on Time Domain Synchronous Orthogonal Frequency Division Multiplexing (TimeDomain Synchronous OFDM, TDS-OFDM) system, so as to improve the spectrum efficiency of the system.

(二)技术方案(2) Technical solution

为解决上述问题,本发明提供了一种时域同步正交频分复用系统的时域加窗方法,包括以下步骤:In order to solve the above problems, the invention provides a time-domain windowing method of a time-domain synchronous OFDM system, comprising the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

优选的,所述步骤S1中,所述训练序列包括m序列、Gold序列、Legendre序列、Walsh序列、Golay序列、上述序列的循环扩展或截断,以及其离散傅里叶变换域为上述序列或上述序列的循环扩展或截断的序列。Preferably, in the step S1, the training sequence includes m-sequence, Gold sequence, Legendre sequence, Walsh sequence, Golay sequence, cyclic extension or truncation of the above-mentioned sequence, and its discrete Fourier transform domain is the above-mentioned sequence or the above-mentioned A cyclic extension of a sequence or a truncated sequence.

优选的,所述训练序列为两段相同的已知序列。Preferably, the training sequence is two identical known sequences.

优选的,所述步骤S2中,所述循环后缀为所述本帧数据块的前L个符号,L为正整数。Preferably, in the step S2, the cyclic suffix is the first L symbols of the data block of the current frame, and L is a positive integer.

优选的,所述步骤S2中,所述循环后缀为所述训练序列的前L个符号,L为正整数。Preferably, in the step S2, the cyclic suffix is the first L symbols of the training sequence, where L is a positive integer.

所述步骤S3中,所述时域加窗处理为:所述本帧训练序列前W/2个符号依次乘以相应的窗函数的前W/2个系数,所述本帧循环后缀的后W/2个符号依次乘以相应的窗函数的后W/2个系数。In the step S3, the time-domain windowing process is as follows: the first W/2 symbols of the training sequence of the current frame are multiplied by the first W/2 coefficients of the corresponding window function in turn, and the post-W/2 coefficients of the cyclic suffix of the current frame The W/2 symbols are sequentially multiplied by the last W/2 coefficients of the corresponding window function.

进一步的,在所述步骤S4之后还包括:Further, after the step S4, it also includes:

S5、对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。S5. Perform subsequent processing operations such as shaping filtering, frequency up-conversion, and digital-to-analog conversion on the signal after time-domain windowing processing.

优选的,所述时域窗函数包括升余弦滚降窗、汉明窗、汉宁窗和凯撒窗。Preferably, the time-domain window function includes a raised cosine roll-off window, a Hamming window, a Hanning window and a Kaiser window.

优选的,所述窗长度W受所述数据块长度、训练序列长度或循环后缀长度约束,其不超过数据块长度的1/16,或者不超过时域训练序列长度,或者不超过循环后缀长度的两倍。Preferably, the window length W is constrained by the data block length, training sequence length or cyclic suffix length, which does not exceed 1/16 of the data block length, or does not exceed the time domain training sequence length, or does not exceed the cyclic suffix length twice as much.

本发明还提供了一种时域同步正交频分复用系统的时域加窗装置,该装置包括:The present invention also provides a time-domain windowing device of a time-domain synchronous OFDM system, the device comprising:

时域同步正交频分复用帧产生模块,用于根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧;A time-domain synchronous OFDM frame generation module is used to generate a time-domain synchronous OFDM system signal frame after combining the training sequence and the corresponding inverse discrete Fourier transform data block according to the system transmission parameters;

循环后缀产生模块,与所述时域同步正交频分复用帧产生模块相连,用于将本帧数据块的前L个符号或者本帧训练序列的前L个符号复制到当前帧数据块之后,产生本帧的循环后缀,L为正整数;The cyclic suffix generation module is connected with the TDOFDM frame generation module, and is used to copy the first L symbols of the data block of this frame or the first L symbols of the training sequence of this frame to the data block of the current frame Afterwards, the cyclic suffix of this frame is generated, and L is a positive integer;

时域加窗模块,与所述循环后缀产生模块相连,用于对本帧训练序列前W/2个符号和本帧循环后缀的后W/2个符号进行时域加窗处理,W为窗长度;The time-domain windowing module is connected with the cyclic suffix generation module, and is used to perform time-domain windowing processing on the W/2 symbols before the training sequence of this frame and the W/2 symbols of the cyclic suffix of this frame, and W is the window length ;

时域叠加模块,与所述时域加窗模块相连,用于将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的后W/2个符号在时域依次相加;The time domain superposition module is connected with the described time domain windowing module, and is used to process the first W/2 symbols of the training sequence of this frame after the time domain windowing process and the previous frame cyclic suffix after the time domain windowing process. W/2 symbols are sequentially added in the time domain;

后续处理模块,与所述时域叠加模块相连,用于对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。The subsequent processing module is connected with the time domain superposition module, and is used for performing subsequent processing operations such as shaping filtering, frequency up-conversion and digital-to-analog conversion on the signal processed by time domain windowing.

(三)有益效果(3) Beneficial effects

基于本发明方案的时域加窗方法及装置,通信系统可以获得更高的频谱效率。本发明实现过程简单、复杂度低,可以在复杂的无线传输通道环境中有效地使用。Based on the time domain windowing method and device of the solution of the present invention, the communication system can obtain higher spectrum efficiency. The invention has simple implementation process and low complexity, and can be effectively used in complex wireless transmission channel environments.

附图说明Description of drawings

图1是现有技术中CP-OFDM帧结构的一种示意图;FIG. 1 is a schematic diagram of a CP-OFDM frame structure in the prior art;

图2是现有技术中TDS-OFDM帧结构的一种示意图;Fig. 2 is a kind of schematic diagram of TDS-OFDM frame structure in the prior art;

图3是本发明方法的流程图;Fig. 3 is a flow chart of the inventive method;

图4是本发明提出的一种基于TDS-OFDM的帧结构示意图;Fig. 4 is a kind of frame structure diagram based on TDS-OFDM that the present invention proposes;

图5是本发明提出的一种基于TDS-OFDM的帧结构加窗方法示意图;Fig. 5 is a schematic diagram of a frame structure windowing method based on TDS-OFDM proposed by the present invention;

图6是本发明实施例一和三中的帧循环后缀的产生方法示意图;6 is a schematic diagram of a method for generating a frame cyclic suffix in Embodiments 1 and 3 of the present invention;

图7是本发明实施例二和四中的帧循环后缀的产生方法示意图;FIG. 7 is a schematic diagram of a method for generating a frame cyclic suffix in Embodiments 2 and 4 of the present invention;

图8是本发明实施例的相邻帧的叠加方法示意图;FIG. 8 is a schematic diagram of a method for superimposing adjacent frames according to an embodiment of the present invention;

图9是本发明提出的一种基于TDS-OFDM的帧结构加窗方法的频谱效率效果图;Fig. 9 is a spectrum efficiency effect diagram of a frame structure windowing method based on TDS-OFDM proposed by the present invention;

图10是本发明装置的结构图。Fig. 10 is a structural diagram of the device of 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。以下实施例用于说明本发明,但不用来限制本发明的范围。The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

图3是本发明方法的流程图,具体包括以下步骤:Fig. 3 is the flowchart of the inventive method, specifically comprises the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

优选的,所述步骤S1中,所述训练序列包括m序列、Gold序列、Legendre序列、Walsh序列、Golay序列、上述序列的循环扩展或截断,以及其离散傅里叶变换域为上述序列或上述序列的循环扩展或截断的序列。Preferably, in the step S1, the training sequence includes m-sequence, Gold sequence, Legendre sequence, Walsh sequence, Golay sequence, cyclic extension or truncation of the above-mentioned sequence, and its discrete Fourier transform domain is the above-mentioned sequence or the above-mentioned A cyclic extension of a sequence or a truncated sequence.

优选的,所述训练序列为两段相同的已知序列。Preferably, the training sequence is two identical known sequences.

优选的,所述步骤S2中,所述循环后缀为所述本帧数据块的前L个符号,L为正整数。Preferably, in the step S2, the cyclic suffix is the first L symbols of the data block of the current frame, and L is a positive integer.

优选的,所述步骤S2中,所述循环后缀为所述训练序列的前L个符号,L为正整数。Preferably, in the step S2, the cyclic suffix is the first L symbols of the training sequence, where L is a positive integer.

所述步骤S3中,所述时域加窗处理为:所述本帧训练序列前W/2个符号依次乘以相应的窗函数的前W/2个系数,所述本帧循环后缀的后W/2个符号依次乘以相应的窗函数的后W/2个系数。In the step S3, the time-domain windowing process is as follows: the first W/2 symbols of the training sequence of the current frame are multiplied by the first W/2 coefficients of the corresponding window function in turn, and the post-W/2 coefficients of the cyclic suffix of the current frame The W/2 symbols are sequentially multiplied by the last W/2 coefficients of the corresponding window function.

进一步的,在所述步骤S4之后还包括:Further, after the step S4, it also includes:

S5、对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。S5. Perform subsequent processing operations such as shaping filtering, frequency up-conversion, and digital-to-analog conversion on the signal after time-domain windowing processing.

优选的,所述时域窗函数包括升余弦滚降窗、汉明窗、汉宁窗和凯撒窗。Preferably, the time-domain window function includes a raised cosine roll-off window, a Hamming window, a Hanning window and a Kaiser window.

优选的,所述窗长度W受所述数据块长度、训练序列长度或循环后缀长度约束,其不超过数据块长度的1/16,或者不超过时域训练序列长度,或者不超过循环后缀长度的两倍。Preferably, the window length W is constrained by the data block length, training sequence length or cyclic suffix length, which does not exceed 1/16 of the data block length, or does not exceed the time domain training sequence length, or does not exceed the cyclic suffix length twice as much.

实施例1Example 1

实施例1具体描述一个具有复帧结构并基于连续TDS-OFDM的帧结构加窗方法的工作流程。本实施例中帧结构如图4所示,加窗方法如图5所示,其中N1表示训练序列第一段组成序列的长度,N2表示训练序列第二段组成序列的长度,N表示时域数据块的长度。Embodiment 1 specifically describes the workflow of a frame structure windowing method with a multi-frame structure and based on continuous TDS-OFDM. The frame structure in this embodiment is shown in Figure 4, and the windowing method is shown in Figure 5, wherein N1 represents the length of the first segment of the training sequence, N2 represents the length of the second segment of the training sequence, and N represents the time domain The length of the data block.

在所述OFDM系统中,保护间隔填充的训练序列与OFDM数据块组成一个信号帧,数据块间填充的训练序列由本实施例中的两段相同的序列组成。帧结构加窗方法具体包括如下步骤:In the OFDM system, the training sequence filled in the guard interval and the OFDM data block form a signal frame, and the training sequence filled between the data blocks consists of two identical sequences in this embodiment. The frame structure windowing method specifically includes the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

本实施例采用的训练序列由两段相同的序列组成。其中,每段序列其离散傅里叶变换域为长度为256的m序列,即N1=N2=256。此序列是8阶的m序列,由一个Fibonacci型线性反馈移位寄存器(LFSR)实现。其特征多项式定义为x8+x6+x5+x+1。然后将上述的m序列做长度为256的IDFT(Inverse Discrete Fourier Transform,离散傅里叶反变换)变成长度为256的时域序列。然后将两段相同的时域序列组合构成总长度为512的训练序列。The training sequence used in this embodiment consists of two identical sequences. Among them, the discrete Fourier transform domain of each sequence is an m-sequence with a length of 256, that is, N1=N2=256. This sequence is an 8-order m-sequence implemented by a Fibonacci-type linear feedback shift register (LFSR). Its characteristic polynomial is defined as x 8 +x 6 +x 5 +x+1. Then the above m-sequence is converted into a time-domain sequence of length 256 by IDFT (Inverse Discrete Fourier Transform) with a length of 256. Then two identical time-domain sequences are combined to form a training sequence with a total length of 512.

在本实施例中,每一帧传输4096个数据符号,即N=4096。在生成训练序列的同时,产生本帧的待传输数据比特,经过FEC(ForwardError Coding,前向纠错编码)和交织,然后进行星座映射获得本帧的4096个传输数据符号,经过IDFT后获得长度为4096的时域数据块。In this embodiment, 4096 data symbols are transmitted in each frame, that is, N=4096. While generating the training sequence, generate the data bits to be transmitted in this frame, go through FEC (Forward Error Coding, forward error correction coding) and interleaving, and then perform constellation mapping to obtain 4096 transmission data symbols in this frame, and obtain the length after IDFT 4096 blocks of time domain data.

在时域,将训练序列置于时域数据块之前组合后产生本帧的TDS-OFDM系统信号帧。In the time domain, the TDS-OFDM system signal frame of this frame is generated after the training sequence is placed before the time domain data block and combined.

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

本实施例中,优选地,参数L选为32,将本帧数据块的前32个符号复制到本帧数据块之后,产生本帧的循环后缀,如图6所示。这样本帧的总长度就变为了256×2+4096+32=4640。In this embodiment, preferably, the parameter L is selected as 32, and the first 32 symbols of the data block of this frame are copied to the data block of this frame to generate a cyclic suffix of this frame, as shown in FIG. 6 . In this way, the total length of this frame becomes 256×2+4096+32=4640.

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

本实施例中,为了更好地降低带外功率提高频谱效率同时兼顾传输速率,优选地,采用贝塔参数为10的凯撒窗作为加窗处理的窗函数,窗长度为W,W受数据块长度、训练序列长度和循环后缀长度约束的约束,本实施例中,W取64。In this embodiment, in order to better reduce the out-of-band power and improve the spectral efficiency while taking into account the transmission rate, preferably, a Caesar window with a beta parameter of 10 is used as the window function of the windowing process, and the window length is W, and W is affected by the data block length . Constraints on the training sequence length and the cyclic suffix length constraint. In this embodiment, W is 64.

时域加窗处理的过程如下:将本帧的前32个符号(本帧训练序列的前32个符号)分别乘以窗的前32个系数,将本帧的后32个符号(循环后缀的后32个符号)分别乘以窗的后32个系数。The process of windowing in the time domain is as follows: multiply the first 32 symbols of this frame (the first 32 symbols of the training sequence of this frame) by the first 32 coefficients of the window, and multiply the last 32 symbols of this frame (the first 32 symbols of the cyclic suffix The last 32 symbols) are multiplied by the last 32 coefficients of the window respectively.

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

在本实施例中,由于是连续系统的帧结构,可以通过相邻帧的部分叠加来获得一定的传输效率:将本帧训练序列经过时域加窗处理后的前32个符号与前帧循环后缀经过时域加窗处理后的32个符号对齐并在时域依次相加,如图8所示;相应地,将本帧循环后缀经过加窗处理后的后32个符号与后帧训练序列经过时域加窗处理后的前32个符号对齐并在时域依次相加。经过这样的处理后,就能够从一定程度上抵消时域加窗所带来的传输效率的降低,使得每帧等效的实际传输符号数为256×2+4096=4608。经过加窗处理与未经过加窗处理后的频谱效果对比图如图9所示。In this embodiment, due to the frame structure of the continuous system, a certain transmission efficiency can be obtained by partial superposition of adjacent frames: the first 32 symbols of the training sequence of this frame after time-domain windowing processing and the previous frame cycle The 32 symbols of the suffix processed by windowing in the time domain are aligned and added sequentially in the time domain, as shown in Figure 8; correspondingly, the last 32 symbols of the frame cyclic suffix processed by windowing are combined with the training sequence of the rear frame The first 32 symbols after time-domain windowing are aligned and sequentially added in the time domain. After such processing, the decrease in transmission efficiency caused by time-domain windowing can be offset to a certain extent, so that the equivalent number of actual transmission symbols per frame is 256×2+4096=4608. Figure 9 shows the comparison of spectrum effects after windowing processing and without windowing processing.

本实施例中,在将相邻帧进行叠加处理之后,依次进行成型滤波、数字上变频和数模转换,将信号发送出去。In this embodiment, after superposition processing is performed on adjacent frames, shaping filtering, digital up-conversion and digital-to-analog conversion are performed in sequence, and the signal is sent out.

实施例2Example 2

实施例2具体描述一个具有复帧结构并基于连续TDS-OFDM的帧结构加窗方法的工作流程。本实施例中帧结构如图4所示,加窗方法如图5所示,各参数描述同实施例1。Embodiment 2 specifically describes the working process of a frame structure windowing method with a multi-frame structure and based on continuous TDS-OFDM. The frame structure in this embodiment is shown in FIG. 4 , the windowing method is shown in FIG. 5 , and the description of each parameter is the same as that in Embodiment 1.

在所述OFDM系统中,保护间隔填充的训练序列与OFDM数据块组成一个信号帧,数据块间填充的训练序列由本实施例中的两段长度不同的序列组成。帧结构加窗方法具体包括如下步骤:In the OFDM system, the training sequence filled in the guard interval and the OFDM data block form a signal frame, and the training sequence filled between the data blocks consists of two sequences of different lengths in this embodiment. The frame structure windowing method specifically includes the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

本实施例采用的训练序列由两段长度不同的序列组成。其中,第一段序列是第二段序列的循环扩展,第二段序列是长度为255的m序列,第一段序列是第二段序列的后165个符号组成的序列,即N1=165,N2=255。然后将这两段时域序列组合构成总长度为420的训练序列。The training sequence used in this embodiment consists of two sequences with different lengths. Among them, the first sequence is the cyclic extension of the second sequence, the second sequence is an m sequence with a length of 255, and the first sequence is a sequence composed of the last 165 symbols of the second sequence, that is, N1=165, N2=255. Then the two time-domain sequences are combined to form a training sequence with a total length of 420.

在本实施例中,每一帧传输3072个数据符号,即N=3072。在生成训练序列的同时,产生本帧的待传输数据比特,经过FEC和交织,然后进行星座映射获得本帧的3072个传输数据符号,经过IDFT后获得长度为3072的时域数据块。In this embodiment, 3072 data symbols are transmitted in each frame, that is, N=3072. While generating the training sequence, generate the data bits to be transmitted in this frame, go through FEC and interleaving, and then perform constellation mapping to obtain 3072 transmission data symbols in this frame, and obtain a time-domain data block with a length of 3072 after IDFT.

在时域,将训练序列置于时域数据块之前组合后产生本帧的TDS-OFDM系统信号帧。In the time domain, the TDS-OFDM system signal frame of this frame is generated after the training sequence is placed before the time domain data block and combined.

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

本实施例中,优选地,参数L选为64,将本帧训练序列的前64个符号复制到本帧数据块之后,产生本帧的循环后缀,如图7所示。这样本帧的总长度就变为了165+255+3072+64=3556。In this embodiment, preferably, the parameter L is selected as 64, and the first 64 symbols of the training sequence of the frame are copied to the data block of the frame to generate the cyclic suffix of the frame, as shown in FIG. 7 . In this way, the total length of this frame becomes 165+255+3072+64=3556.

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

本实施例中,为了更好地降低带外功率提高频谱效率同时兼顾传输速率,优选地,采用汉明窗作为加窗处理的窗函数,窗长度为W,W受到数据块长度的约束,不超过数据块长度的1/16,本实施例中,W取64。In this embodiment, in order to better reduce the out-of-band power and improve the spectral efficiency while taking into account the transmission rate, preferably, a Hamming window is used as the window function of the windowing process, and the window length is W, and W is constrained by the length of the data block. More than 1/16 of the data block length, in this embodiment, W is 64.

时域加窗处理的过程如下:将本帧的前32个符号(本帧训练序列的前32个符号)分别乘以窗的前32个系数,将本帧的后32个符号(循环后缀的后32个符号)分别乘以窗的后32个系数。The process of windowing in the time domain is as follows: multiply the first 32 symbols of this frame (the first 32 symbols of the training sequence of this frame) by the first 32 coefficients of the window, and multiply the last 32 symbols of this frame (the first 32 symbols of the cyclic suffix The last 32 symbols) are multiplied by the last 32 coefficients of the window respectively.

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

在本实施例中,由于是连续系统的帧结构,可以通过相邻帧的部分叠加来获得一定的传输效率:将本帧训练序列经过时域加窗处理后的前32个符号与前帧循环后缀经过时域加窗处理后的32个符号对齐并在时域依次相加,如图8所示;相应地,将本帧循环后缀经过加窗处理后的后32个符号与后帧训练序列经过时域加窗处理后的前32个符号对齐并在时域依次相加。经过这样的处理后,就能够从一定程度上抵消时域加窗所带来的传输效率的降低,使得每帧等效的实际传输符号数为165+255+3072=3492。In this embodiment, due to the frame structure of the continuous system, a certain transmission efficiency can be obtained by partial superposition of adjacent frames: the first 32 symbols of the training sequence of this frame after time-domain windowing processing and the previous frame cycle The 32 symbols of the suffix processed by windowing in the time domain are aligned and added sequentially in the time domain, as shown in Figure 8; correspondingly, the last 32 symbols of the frame cyclic suffix processed by windowing are combined with the training sequence of the rear frame The first 32 symbols after time-domain windowing are aligned and sequentially added in the time domain. After such processing, the decrease in transmission efficiency caused by time-domain windowing can be offset to a certain extent, so that the equivalent number of actual transmission symbols per frame is 165+255+3072=3492.

本实施例中,在将相邻帧进行叠加处理之后,依次进行成型滤波、数模转换和模拟上变频,将信号发送出去。In this embodiment, after superposition processing is performed on adjacent frames, shaping filtering, digital-to-analog conversion, and analog up-conversion are performed in sequence, and the signals are sent out.

实施例3Example 3

实施例3具体描述一个具有复帧结构并基于连续TDS-OFDM的帧结构加窗方法的工作流程。本实施例中帧结构如图4所示,加窗方法如图5所示,各参数描述同实施例1。Embodiment 3 specifically describes the working process of a frame structure windowing method with a multi-frame structure and based on continuous TDS-OFDM. The frame structure in this embodiment is shown in FIG. 4 , the windowing method is shown in FIG. 5 , and the description of each parameter is the same as that in Embodiment 1.

在所述OFDM系统中,保护间隔填充的训练序列与OFDM数据块组成一个信号帧,数据块间填充的训练序列由本实施例中的两段相同的序列组成。帧结构加窗方法具体包括如下步骤:In the OFDM system, the training sequence filled in the guard interval and the OFDM data block form a signal frame, and the training sequence filled between the data blocks consists of two identical sequences in this embodiment. The frame structure windowing method specifically includes the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

本实施例采用的训练序列由两段相同的序列组成。其中,每段序列的离散傅里叶变换域为长度为512的Walsh序列,即N1=N2=512。然后将上述的Walsh序列做长度为512的IDFT变成长度为512的时域序列。然后将两段相同的时域序列组合构成总长度为1024的训练序列。The training sequence used in this embodiment consists of two identical sequences. Among them, the discrete Fourier transform domain of each sequence is a Walsh sequence with a length of 512, that is, N1=N2=512. Then, the above-mentioned Walsh sequence is transformed into a time-domain sequence with a length of 512 by IDFT with a length of 512. Then two identical time-domain sequences are combined to form a training sequence with a total length of 1024.

在本实施例中,每一帧传输8192个数据符号,即N=8192。在生成训练序列的同时,产生本帧的待传输数据比特,经过FEC和交织,然后进行星座映射获得本帧的8192个传输数据符号,经过IDFT后获得长度为8192的时域数据块。In this embodiment, each frame transmits 8192 data symbols, that is, N=8192. While generating the training sequence, generate the data bits to be transmitted in this frame, go through FEC and interleaving, and then perform constellation mapping to obtain 8192 transmission data symbols in this frame, and obtain a time-domain data block with a length of 8192 after IDFT.

在时域,将训练序列置于时域数据块之前组合后产生本帧的TDS-OFDM系统信号帧。In the time domain, the TDS-OFDM system signal frame of this frame is generated after the training sequence is placed before the time domain data block and combined.

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

本实施例中,优选地,参数L选为128,将本帧数据块的前128个符号复制到本帧数据块之后,产生本帧的循环后缀,如图6所示。这样本帧的总长度就变为了512×2+8192+128=9344。In this embodiment, preferably, the parameter L is selected as 128, and the first 128 symbols of the data block of this frame are copied to the data block of this frame to generate a cyclic suffix of this frame, as shown in FIG. 6 . In this way, the total length of this frame becomes 512×2+8192+128=9344.

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

本实施例中,为了更好地降低带外功率提高频谱效率同时兼顾传输速率,优选地,采用海宁窗作为加窗处理的窗函数,窗长度为W,W受到训练长度的约束,不超过训练序列的长度,本实施例中,W取128。In this embodiment, in order to better reduce the out-of-band power and improve the spectral efficiency while taking into account the transmission rate, preferably, the Haining window is used as the window function of the windowing process, and the window length is W. W is constrained by the training length and does not exceed the training The length of the sequence, in this embodiment, W is 128.

时域加窗处理的过程如下:将本帧的前64个符号(本帧训练序列的前64个符号)分别乘以窗的前64个系数,将本帧的后64个符号(循环后缀的后64个符号)分别乘以窗的后64个系数。The process of windowing in the time domain is as follows: multiply the first 64 symbols of this frame (the first 64 symbols of the training sequence of this frame) by the first 64 coefficients of the window, and multiply the last 64 symbols of this frame (the first 64 symbols of the cyclic suffix The last 64 symbols) are multiplied by the last 64 coefficients of the window respectively.

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

在本实施例中,由于是连续系统的帧结构,可以通过相邻帧的部分叠加来获得一定的传输效率:将本帧训练序列经过时域加窗处理后的前64个符号与前帧循环后缀经过时域加窗处理后的64个符号对齐并在时域依次相加,如图8所示;相应地,将本帧循环后缀经过加窗处理后的后64个符号与后帧训练序列经过时域加窗处理后的前64个符号对齐并在时域依次相加。经过这样的处理后,就能够从一定程度上抵消时域加窗所带来的传输效率的降低,使得每帧等效的实际传输符号数为512×2+8192+128-64=9280。In this embodiment, due to the frame structure of the continuous system, a certain transmission efficiency can be obtained by partial superposition of adjacent frames: the first 64 symbols of the training sequence of this frame after time-domain windowing processing and the previous frame cycle The 64 symbols of the suffix after windowing in the time domain are aligned and added sequentially in the time domain, as shown in Figure 8; correspondingly, the last 64 symbols of the frame cyclic suffix after windowing are combined with the training sequence of the rear frame The first 64 symbols after time-domain windowing are aligned and sequentially added in the time domain. After such processing, the decrease in transmission efficiency caused by time-domain windowing can be offset to a certain extent, so that the equivalent number of actual transmission symbols per frame is 512×2+8192+128-64=9280.

本实施例中,在将相邻帧进行叠加处理之后,依次进行成型滤波、数字上变频和数模转换后,将信号发送出去。In this embodiment, after superposition processing is performed on adjacent frames, shaping filtering, digital up-conversion and digital-to-analog conversion are performed in sequence, and then the signal is sent out.

实施例4Example 4

实施例4具体描述一个具有复帧结构并基于突发TDS-OFDM的帧结构加窗方法的工作流程。本实施例中帧结构如图4所示,加窗方法如图5所示,各参数描述同实施例1。Embodiment 4 specifically describes the workflow of a frame structure windowing method with a multi-frame structure and based on burst TDS-OFDM. The frame structure in this embodiment is shown in FIG. 4 , the windowing method is shown in FIG. 5 , and the description of each parameter is the same as that in Embodiment 1.

在所述OFDM系统中,保护间隔填充的训练序列与OFDM数据块组成一个信号帧,数据块间填充的训练序列由本实施例中的两段相同的序列组成。帧结构加窗方法具体包括如下步骤:In the OFDM system, the training sequence filled in the guard interval and the OFDM data block form a signal frame, and the training sequence filled between the data blocks consists of two identical sequences in this embodiment. The frame structure windowing method specifically includes the following steps:

S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn;

本实施例采用的训练序列由两段相同的序列组成。其中,每段序列为长度为512的Legendre序列,即N1=N2=512。然后将两段相同的序列组合构成总长度为1024的时域训练序列。The training sequence used in this embodiment consists of two identical sequences. Among them, each sequence is a Legendre sequence with a length of 512, that is, N1=N2=512. Then two identical sequences are combined to form a time-domain training sequence with a total length of 1024.

在本实施例中,每一帧传输8192个数据符号,即N=8192。在生成训练序列的同时,产生本帧的待传输数据比特,经过FEC和交织,然后进行星座映射获得本帧的8192个传输数据符号,经过IDFT后获得长度为8192的时域数据块。In this embodiment, each frame transmits 8192 data symbols, that is, N=8192. While generating the training sequence, generate the data bits to be transmitted in this frame, go through FEC and interleaving, and then perform constellation mapping to obtain 8192 transmission data symbols in this frame, and obtain a time-domain data block with a length of 8192 after IDFT.

在时域,将时域训练序列置于时域数据块之前组合后产生本帧的TDS-OFDM系统信号帧。In the time domain, the TDS-OFDM system signal frame of this frame is generated after combining the time domain training sequence before the time domain data block.

S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame;

本实施例中,参数L选为64,将本帧训练序列的前64个符号复制到当前帧数据块之后,产生本帧的循环后缀,如图7所示。这样本帧的总长度就变为了512×2+8192+64=9280。In this embodiment, the parameter L is selected as 64, and the first 64 symbols of the training sequence of the current frame are copied to the data block of the current frame to generate a cyclic suffix of the current frame, as shown in FIG. 7 . In this way, the total length of this frame becomes 512×2+8192+64=9280.

S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length;

本实施例中,为了更好地降低带外功率提高频谱效率同时兼顾传输速率,优选地,采用汉宁窗作为加窗处理的窗函数,窗长度为W,W受到循环后缀长度的约束,不超过循环后缀长度的两倍,本实施例中,W取32。In this embodiment, in order to better reduce the out-of-band power and improve the spectral efficiency while taking into account the transmission rate, preferably, the Hanning window is used as the window function of the windowing process, and the window length is W, and W is constrained by the length of the cyclic suffix. More than twice the length of the cyclic suffix, in this embodiment, W is 32.

时域加窗处理的过程如下:将本帧数据的前32个符号(本帧训练序列的前32个符号)分别乘以窗的前32个系数,将本帧数据的后32个符号(数据循环后缀的后32个符号)分别乘以窗的后32个系数。The process of windowing in the time domain is as follows: multiply the first 32 symbols of the frame data (the first 32 symbols of the training sequence of the frame) by the first 32 coefficients of the window, and multiply the last 32 symbols of the frame data (data The last 32 symbols of the cyclic suffix) are multiplied by the last 32 coefficients of the window respectively.

S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain.

在本实施例中,由于是突发系统的帧结构,因此没有相邻帧来进行部分叠加,因此这个步骤省略。In this embodiment, due to the frame structure of the burst system, there is no adjacent frame for partial superposition, so this step is omitted.

本实施例中,将帧体依次进行成型滤波、数模转换和模拟上变频,将信号发送出去。In this embodiment, the frame body is sequentially subjected to shaping filtering, digital-to-analog conversion, and analog up-conversion, and the signal is sent out.

实施例5Example 5

图10是本发明装置的结构图,本发明还提供了一种时域同步正交频分复用系统的时域加窗装置,该装置包括:Fig. 10 is a structural diagram of the device of the present invention. The present invention also provides a time-domain windowing device for a time-domain synchronous OFDM system, which includes:

时域同步正交频分复用(TDS-OFDM)帧产生模块,用于根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用(TDS-OFDM)系统信号帧;Time Domain Synchronous Orthogonal Frequency Division Multiplexing (TDS-OFDM) frame generation module, used to generate Time Domain Synchronous Orthogonal Frequency Division Multiplexing after combining the training sequence and the corresponding inverse discrete Fourier transform data block according to the system transmission parameters Use (TDS-OFDM) system signal frame;

循环后缀产生模块,与所述时域同步正交频分复用帧产生模块相连,用于将本帧数据块的前L个符号或者本帧训练序列的前L个符号复制到当前帧数据块之后,产生本帧的循环后缀,L为正整数;The cyclic suffix generation module is connected with the TDOFDM frame generation module, and is used to copy the first L symbols of the data block of this frame or the first L symbols of the training sequence of this frame to the data block of the current frame Afterwards, the cyclic suffix of this frame is generated, and L is a positive integer;

时域加窗模块,与所述循环后缀产生模块相连,用于对本帧训练序列前W/2个符号和本帧循环后缀的后W/2个符号进行时域加窗处理,W为窗长度;The time-domain windowing module is connected with the cyclic suffix generation module, and is used to perform time-domain windowing processing on the W/2 symbols before the training sequence of this frame and the W/2 symbols of the cyclic suffix of this frame, and W is the window length ;

时域叠加模块,与所述时域加窗模块相连,用于将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的后W/2个符号在时域依次相加;The time domain superposition module is connected with the described time domain windowing module, and is used to process the first W/2 symbols of the training sequence of this frame after the time domain windowing process and the previous frame cyclic suffix after the time domain windowing process. W/2 symbols are sequentially added in the time domain;

后续处理模块,与所述时域叠加模块相连,用于对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。The subsequent processing module is connected with the time domain superposition module, and is used for performing subsequent processing operations such as shaping filtering, frequency up-conversion and digital-to-analog conversion on the signal processed by time domain windowing.

以上所述仅是本发明的优选实施方式,应当指出,对于本技术领域的普通技术人员来说,在不脱离本发明技术原理的前提下,还可以做出若干改进和替换,这些改进和替换也应视为本发明的保护范围。The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and replacements can also be made, these improvements and replacements It should also be regarded as the protection scope of the present invention.

Claims (10)

1.一种时域同步正交频分复用系统的时域加窗方法,其特征在于,包括以下步骤:1. a time domain windowing method of time domain synchronous OFDM system, is characterized in that, comprises the following steps: S1、根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧,将当前时域同步正交频分复用信号帧定义为本帧,其前、后信号帧依次定义为前帧、后帧;S1. According to the system transmission parameters, the training sequence and the corresponding inverse discrete Fourier transform data block are combined to generate a time-domain synchronous OFDM system signal frame, and the current time-domain synchronous OFDM signal frame is generated Defined as this frame, the previous and subsequent signal frames are defined as the previous frame and the subsequent frame in turn; S2、生成本帧的循环后缀,并复制到本帧数据块之后;S2. Generate the cyclic suffix of this frame, and copy it after the data block of this frame; S3、对本帧训练序列前W/2个符号和循环后缀的后W/2个符号进行时域加窗处理,其中W是窗长度;S3. Perform time-domain windowing processing on the first W/2 symbols of the training sequence of this frame and the last W/2 symbols of the cyclic suffix, where W is the window length; S4、将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的W/2个符号在时域依次相加。S4. Add the first W/2 symbols of the training sequence of this frame after time-domain windowing processing to the W/2 symbols of the previous frame cyclic suffix after time-domain windowing processing in the time domain. 2.如权利要求1所述的方法,其特征在于,所述步骤S1中,所述训练序列包括m序列、Gold序列、Legendre序列、Walsh序列、Golay序列、上述序列的循环扩展或截断,以及其离散傅里叶变换域为上述序列或上述序列的循环扩展或截断的序列。2. the method for claim 1 is characterized in that, in described step S1, described training sequence comprises m sequence, Gold sequence, Legendre sequence, Walsh sequence, Golay sequence, the cyclic extension or truncation of above-mentioned sequence, and Its discrete Fourier transform domain is the above sequence or a cyclically extended or truncated sequence of the above sequence. 3.如权利要求1所述的方法,其特征在于,所述训练序列为两段相同的已知序列。3. The method according to claim 1, wherein the training sequence is two identical known sequences. 4.如权利要求1所述的方法,其特征在于,所述步骤S2中,所述循环后缀为所述本帧数据块的前L个符号,L为正整数。4. The method according to claim 1, wherein in the step S2, the cyclic suffix is the first L symbols of the data block of the current frame, and L is a positive integer. 5.如权利要求1所述的方法,其特征在于,所述步骤S2中,所述循环后缀为所述训练序列的前L个符号,L为正整数。5. The method according to claim 1, wherein in the step S2, the cyclic suffix is the first L symbols of the training sequence, and L is a positive integer. 6.如权利要求1所述的方法,其特征在于,所述步骤S3中,所述时域加窗处理为:所述本帧训练序列前W/2个符号依次乘以相应的窗函数的前W/2个系数,所述本帧循环后缀的后W/2个符号依次乘以相应的窗函数的后W/2个系数。6. The method according to claim 1, characterized in that, in the step S3, the time-domain windowing process is: the W/2 symbols before the training sequence of the frame are multiplied by the corresponding window function successively For the first W/2 coefficients, the last W/2 symbols of the cyclic suffix of the current frame are multiplied by the last W/2 coefficients of the corresponding window function in turn. 7.如权利要求1所述的方法,其特征在于,在所述步骤S4之后进一步包括:7. The method according to claim 1, further comprising after the step S4: S5、对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。S5. Perform subsequent processing operations such as shaping filtering, frequency up-conversion, and digital-to-analog conversion on the signal after time-domain windowing processing. 8.如权利要求1或6所述的方法,其特征在于,所述时域窗函数包括升余弦滚降窗、汉明窗、汉宁窗和凯撒窗。8. The method according to claim 1 or 6, wherein the time domain window function comprises a raised cosine roll-off window, a Hamming window, a Hanning window and a Kaiser window. 9.如权利要求1或6所述的方法,其特征在于,所述窗长度W受所述数据块长度、训练序列长度或循环后缀长度约束,其不超过数据块长度的1/16,或者不超过时域训练序列长度,或者不超过循环后缀长度的两倍。9. The method according to claim 1 or 6, wherein the window length W is constrained by the data block length, training sequence length or cyclic suffix length, and it does not exceed 1/16 of the data block length, or Not exceeding the length of the time-domain training sequence, or not exceeding twice the length of the cyclic suffix. 10.一种时域同步正交频分复用系统的时域加窗装置,其特征在于,该装置包括:10. A time-domain windowing device of a time-domain synchronous OFDM system, characterized in that the device comprises: 时域同步正交频分复用帧产生模块,用于根据系统传输参数,将训练序列和对应的离散傅里叶反变换数据块组合后产生时域同步正交频分复用系统信号帧;A time-domain synchronous OFDM frame generation module is used to generate a time-domain synchronous OFDM system signal frame after combining the training sequence and the corresponding inverse discrete Fourier transform data block according to the system transmission parameters; 循环后缀产生模块,与所述时域同步正交频分复用帧产生模块相连,用于将本帧数据块的前L个符号或者本帧训练序列的前L个符号复制到当前帧数据块之后,产生本帧的循环后缀,L为正整数;The cyclic suffix generation module is connected with the TDOFDM frame generation module, and is used to copy the first L symbols of the data block of this frame or the first L symbols of the training sequence of this frame to the data block of the current frame Afterwards, the cyclic suffix of this frame is generated, and L is a positive integer; 时域加窗模块,与所述循环后缀产生模块相连,用于对本帧训练序列前W/2个符号和本帧循环后缀的后W/2个符号进行时域加窗处理,W为窗长度;The time-domain windowing module is connected with the cyclic suffix generation module, and is used to perform time-domain windowing processing on the W/2 symbols before the training sequence of this frame and the W/2 symbols of the cyclic suffix of this frame, and W is the window length ; 时域叠加模块,与所述时域加窗模块相连,用于将本帧训练序列经过时域加窗处理后的前W/2个符号与前帧循环后缀经过时域加窗处理后的后W/2个符号在时域依次相加;The time domain superposition module is connected with the described time domain windowing module, and is used to process the first W/2 symbols of the training sequence of this frame after the time domain windowing process and the previous frame cyclic suffix after the time domain windowing process. W/2 symbols are sequentially added in the time domain; 后续处理模块,与所述时域叠加模块相连,用于对时域加窗处理后的信号进行成型滤波、上变频和数模转换等后续处理操作。The subsequent processing module is connected with the time domain superposition module, and is used for performing subsequent processing operations such as shaping filtering, frequency up-conversion and digital-to-analog conversion on the signal processed by time domain windowing.
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