CN102571660B

CN102571660B - RT-based N-order continuous OFDM method and device in communication system

Info

Publication number: CN102571660B
Application number: CN201010600915.8A
Authority: CN
Inventors: 梁其辉; 肖悦; 刘辰; 薛梅; 黄若愚; 李品; 李少谦
Original assignee: Alcatel Lucent Shanghai Bell Co Ltd; University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China; Nokia Shanghai Bell Co Ltd
Priority date: 2010-12-20
Filing date: 2010-12-20
Publication date: 2016-01-13
Anticipated expiration: 2030-12-20
Also published as: CN102571660A

Abstract

The object of the present invention is to provide a method and device for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system. Wherein, the device generates a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal; performs OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted. The present invention introduces the method (RT) of using the reserved frequency in the OFDM system. For the received signal, the receiver can easily discard the signal used for the reserved frequency, and send the remaining noise-added digital signal to the detector for normal detection. Therefore, the implementation method of RT-based N-order continuous signal at the receiver does not require additional operations to recover the signal, and at the same time, this method brings more degrees of freedom to the receiver to counteract the channel and noise caused by the downlink. distortion.

Description

RT-based N-order continuous OFDM method and device in communication system

技术领域 technical field

本发明涉及基于OFDM的通信技术领域，尤其涉及一种在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的技术。The present invention relates to the technical field of OFDM-based communication, in particular to a technology for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system.

背景技术 Background technique

正交频分复用(OFDM)是一个具备许多性能优势的非常受欢迎的调制技术，并且已经被IEEE802.11a，IEEE802.11g，IEEE802.16，欧洲数字音频广播(DAB)，欧洲数字图像广播(DVB)等技术标准所采纳。然而，该技术相对较慢的频谱边缘衰减效应成为了其在无线通信系统和有线通信系统中应用的一个主要问题。Orthogonal Frequency Division Multiplexing (OFDM) is a very popular modulation technique with many performance advantages, and has been adopted by IEEE802.11a, IEEE802.11g, IEEE802.16, European Digital Audio Broadcasting (DAB), European Digital Video Broadcasting (DVB) and other technical standards adopted. However, the relatively slow spectral edge attenuation effect of this technology has become a major problem in its application in wireless communication systems and wired communication systems.

许多旁瓣抑制方法被提出来解决这个问题，但所有这些方法的目标都是直接减少带外功率；并且大多数方法都是建立一个旁瓣抑制目标函数的最优模型，这使得发射端变得极为复杂。有别于上述方法，一种称为N阶连续性方法的新方法，通过保持N阶导数在连续OFDM符号的时域边界点的连续性，可以极大地直接降低带外功率。N阶连续性方法的实施很简单，只需要计算矩阵的求逆运算，甚至可以提前算好。该方法的一个缺点是引入失真，为了克服失真，要求接收机具备较高的复杂度。Many sidelobe suppression methods have been proposed to solve this problem, but the goal of all these methods is to directly reduce the out-of-band power; and most methods are to establish an optimal model of the sidelobe suppression objective function, which makes the transmitter become Extremely complicated. Different from the above methods, a new method called the N-order continuity method can greatly directly reduce the out-of-band power by maintaining the continuity of the N-order derivatives at the time-domain boundary points of consecutive OFDM symbols. The implementation of the Nth-order continuity method is very simple, and only needs to calculate the inverse operation of the matrix, and it can even be calculated in advance. A disadvantage of this method is the introduction of distortion, which requires a higher complexity of the receiver in order to overcome the distortion.

传统的N阶连续性方法在发射机端的实现方式如图1所示，包括以下步骤：The implementation of the traditional N-order continuity method at the transmitter is shown in Figure 1, including the following steps:

1)在频域上长度K的第i个OFDM符号d_i，被送到映射模块来产生其是具有很低带外功率的实际的第i个OFDM符号。在最简单情形下，d_i由相位移位键控或者积分幅度调制符号组成。映射的方式如方程(1)所示，1) The ith OFDM symbol d _i of length K in the frequency domain is sent to the mapping module to generate It is the actual ith OFDM symbol with very low out-of-band power. In the simplest case, _di consists of phase shift keying or integrating amplitude modulation symbols. The way of mapping is shown in equation (1),

${\overset{&OverBar; &OverBar;}{d d}}_{i i} = = ((I I - - P P)) {d d}_{i i} + + P P {F f}^{H h} {\overset{&OverBar; &OverBar;}{d d}}_{i i - - 11},, - - - - - - ((11)),,$

其中，P＝F^HA^H(AA^H)^-1AF，P是一个由N阶导数的阶数N和数据载波相对位置决定的一个常量，I是跟P矩阵同大小的单位方阵。是第(i-1)个最终送到离散傅里叶逆变换(IDFT)模块的OFDM符号。(·)^H是复数共轭转置矩阵，(·)^-1是矩阵求逆。假设s_i(t)是OFDM子载波的加权和，其中k∈κ＝{k₀，k₁.，k_K-1}，T_g为循环前缀长度，T_s是OFDM符号中未加入循环前缀前的长度。以及其中所得结果必须被延迟或保存在存储器中用于下一个OFDM符号映射过程。Among them, P=F ^H A ^H (AA ^H ) ^-1 AF, P is a constant determined by the order N of the N-order derivative and the relative position of the data carrier, and I is a unit square matrix with the same size as the P matrix. is the (i-1)th OFDM symbol finally sent to the Inverse Discrete Fourier Transform (IDFT) module. (·) ^H is the complex conjugate transpose matrix, and (·) ^-1 is the matrix inversion. Suppose s _i (t) is the weighted sum of OFDM subcarriers, where k∈κ={k ₀ , k ₁ ., k _K-1 }, T _g is the cyclic prefix length, and T _s is the cyclic prefix not added to the OFDM symbol front length. as well as in The result obtained has to be delayed or kept in memory for the next OFDM symbol mapping process.

2)第i个OFDM信号在频域上为通过离散傅里叶逆变换(IDFT)模块来得到对应的时域上的信号。2) The ith OFDM signal in the frequency domain is The corresponding signal in the time domain is obtained through an inverse discrete Fourier transform (IDFT) module.

3)循环前缀被放到时域信号的头部来对抗多径干扰。3) The cyclic prefix is placed at the head of the time domain signal to combat multipath interference.

4)发射的数字基带信号最终由脉冲成型滤波器产生。4) The transmitted digital baseband signal is finally generated by the pulse shaping filter.

5)将步骤4)中产生的基带信号通过数模转换模块，转换为模拟信号，然后通过射频发射模块将信号移至合适的频带上，生成最终的发射信号。5) Convert the baseband signal generated in step 4) into an analog signal through a digital-to-analog conversion module, and then move the signal to a suitable frequency band through a radio frequency transmission module to generate a final transmission signal.

由此看出，传统的N阶连续OFDM方法对原始信号引入失真，需要在接收机端有额外的操作来去除失真。该去除失真操作尽管不是最优的检测信号方法，但由于在接收机端需要进行迭代处理，使得接收机端具有相对高的复杂度。It can be seen from this that the traditional N-order continuous OFDM method introduces distortion to the original signal, and requires additional operations at the receiver to remove the distortion. Although the distortion removal operation is not an optimal signal detection method, it has a relatively high complexity at the receiver end due to the need for iterative processing at the receiver end.

因此，如何提供一种在避免数字信号引入失真的同时保持N阶连续性OFDM方法，成为目前急需解决的问题之一。Therefore, how to provide a method for maintaining N-order continuous OFDM while avoiding the distortion introduced by the digital signal has become one of the urgent problems to be solved at present.

发明内容 Contents of the invention

本发明的目的是提供一种在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的方法和设备。The object of the present invention is to provide a method and device for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system.

根据本发明的一个方面，提供一种在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的方法，其中，该方法包括以下步骤：According to one aspect of the present invention, there is provided a method for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system, wherein the method includes the following steps:

a由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性；a generating a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal;

b对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。b. Perform OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted.

根据本发明的另一个方面，还提供了一种在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的设备，其中，该设备包括：According to another aspect of the present invention, there is also provided a device for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system, wherein the device includes:

生成装置，用于由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性；A generating device, configured to generate a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal;

处理装置，用于对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。A processing device, configured to perform OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted.

与现有技术相比，本发明在OFDM系统中引入采用预留频率的方法(RT)，将全部可用的子载波被分为两部分，一部分子载波用于数据传输，另一部分作为预留频率，用于旁瓣抑制，从而保持传送信号的N阶连续性。数据信号d_i与预留频率信号C_i占有不同的频率域，例如d_iC_i＝0。对于接收信号，接收机很容易丢弃用于预留频率的信号，而将剩余的加噪数字信号送去检测器正常检测。因此，在接收机端基于RT的N阶连续信号的实现方法并不需要额外操作来恢复信号，同时该方法给接收机带来更多自由度以对抗在下行链路中由信道和噪声引起的失真。Compared with the prior art, the present invention introduces the method (RT) of using reserved frequencies in the OFDM system, and divides all available subcarriers into two parts, one part of subcarriers is used for data transmission, and the other part is used as reserved frequency , for sidelobe suppression, thereby maintaining the N-order continuity of the transmitted signal. The data signal d _i and the reserved frequency signal C _i occupy different frequency domains, for example, d _i C _i =0. For the received signal, it is easy for the receiver to discard the signal used for the reserved frequency, and send the remaining noise-added digital signal to the detector for normal detection. Therefore, the implementation method of RT-based N-order continuous signal at the receiver does not require additional operations to recover the signal, and at the same time, this method brings more degrees of freedom to the receiver to counteract the channel and noise caused by the downlink. distortion.

附图说明 Description of drawings

通过阅读参照以下附图所作的对非限制性实施例所作的详细描述，本发明的其它特征、目的和优点将会变得更明显：Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

图1为传统的N阶连续性方法在发射器端的功能模块示意图；Fig. 1 is a schematic diagram of the functional modules of the traditional N-order continuity method at the transmitter end;

图2为根据本发明的一个方面的在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的方法流程图；2 is a flowchart of a method for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system according to an aspect of the present invention;

图3为传统的N阶连续性方法的功率谱密度图；Fig. 3 is the power spectral density figure of traditional N order continuity method;

图4为根据本发明的一个方面的基于32位等间距放置预留频率的N阶连续性OFDM的功率谱密度图；Fig. 4 is the power spectral density figure of the N-order continuous OFDM based on 32 equidistantly placed reserved frequencies according to an aspect of the present invention;

图5为根据本发明的一个方面的基于32位随机放置预留频率的N阶连续性OFDM的功率谱密度图；Fig. 5 is the power spectral density figure of the N order continuous OFDM based on 32 randomly placed reserved frequencies according to an aspect of the present invention;

图6为根据本发明的一个方面的基于64位等间距放置预留频率的N阶连续性OFDM的功率谱密度图；Fig. 6 is the power spectral density figure of the N-order continuous OFDM based on 64 equidistantly placed reserved frequencies according to one aspect of the present invention;

图7为根据本发明的一个方面的基于64位随机放置预留频率的N阶连续性OFDM的功率谱密度图；Fig. 7 is the power spectral density diagram of the N order continuous OFDM based on 64 randomly placed reserved frequencies according to an aspect of the present invention;

图8为根据本发明的一个方面的在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的在发射器端的功能模块示意图；FIG. 8 is a schematic diagram of functional modules at the transmitter end for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system according to an aspect of the present invention;

图9为3种预留频率放置方式的示意图；FIG. 9 is a schematic diagram of three reserved frequency placement methods;

图10为根据本发明的另一个方面的在基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的设备的示意图。FIG. 10 is a schematic diagram of a device for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system according to another aspect of the present invention.

附图中相同或相似的附图标记代表相同或相似的部件。The same or similar reference numerals in the drawings represent the same or similar components.

具体实施方式 detailed description

下面结合附图对本发明作进一步详细描述。The present invention will be described in further detail below in conjunction with the accompanying drawings.

图2为根据本发明一个方面的方法流程图，示出基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的过程。其中，在步骤S1中，发射机1由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性；在步骤S2中，发射机1对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。在此，所述通信系统包括有线通信系统或无线通信系统。Fig. 2 is a flow chart of a method according to one aspect of the present invention, showing the process of performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system. Wherein, in step S1, transmitter 1 generates a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal; The signal sequence and the reserved signal sequence are subjected to OFDM processing to generate OFDM symbols to be transmitted. Here, the communication system includes a wired communication system or a wireless communication system.

具体地，在步骤S1中，发射机1由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性。更具体地，在步骤S1中，发射机1通过如连续、等间距或者随机等方式放置数据载波信号和预留频率信号，并通过映射的方式使得待OFDM处理的数据信号序列生成相应的预留信号序列。例如，把载波索引集合κ分成两部分：κ₁＝{k₀，k₁，...，k_K-nTR-1}与κ₂＝{k′_K-nTR，k′_K-nTR+1，...，k′_K-1}，其中，nTR表示用于预留和带外功率削减的子载波数量，k₀＜k₁＜...＜k_K-nTR-1，k′_K-nTR＜k′_K-nTR+1＜...＜k′_K-1；对于任何p₁∈κ₁，p₂∈κ₂，不能认为p₁＜p₂或者p₁＞p₂；假设并且Specifically, in step S1, the transmitter 1 generates a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal. More specifically, in step S1, the transmitter 1 places the data carrier signal and the reserved frequency signal in a continuous, equidistant or random manner, and makes the data signal sequence to be processed by OFDM generate a corresponding reserved frequency signal by means of mapping. signal sequence. For example, the carrier index set κ is divided into two parts: κ ₁ ={k ₀ , k ₁ ,...,k _K-nTR-1 } and κ ₂ ={k′ _K-nTR , k′ _K-nTR+1 ,...,k′ _K-1 }, where nTR represents the number of subcarriers used for reservation and out-of-band power reduction, k ₀ <k ₁ <...<k _K-nTR-1 , k′ _{K -nTR} <k′ _K-nTR+1 <...<k′ _K-1 ; for any p ₁ ∈κ ₁ , p ₂ ∈κ ₂ , it cannot be considered that p ₁ <p ₂ or p ₁ >p ₂ ; assume and

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & 11 & 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & 11 \\ {k k}_{00} & {k k}_{11} & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - 11}^{' '} \\ \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot \cdot \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - 11}^{' ' N N} \end{matrix}),,$

其中，第一K-nTR列的F′与A′对应数字信号，最后nTR列F′与A′对应预留频率信号；设B＝A′F′，第一个K-nTR列的A′和B分别记作为A₁和B₁，A₂与B₂表示最后列的A′与B。那么预留信号对于第i个OFDM符号的频域值C_i具体如下方程(2)表示：Among them, F' and A' of the first K-nTR column correspond to digital signals, and the last nTR column F' and A' correspond to reserved frequency signals; suppose B=A'F', A' of the first K-nTR column and B are denoted as A ₁ and B ₁ , respectively, and A ₂ and B ₂ represent A' and B in the last column. Then the frequency domain value C _i of the reserved signal for the ith OFDM symbol is specifically expressed in the following equation (2):

${C C}_{i i}^{' '} = = {B B}_{22}^{+ +} (({A A}_{11} {d d}_{i i - - 11}^{' '} + + {A A}_{22} {C C}_{i i - - 11}^{' '} - - {B B}_{11} {d d}_{i i}^{' '}))$

$= = {B B}_{22}^{+ +} {A A}_{22} {C C}_{i i - - 11}^{' '} + + {B B}_{22}^{+ +} {A A}_{11} {d d}_{i i - - 11}^{' '} - - {B B}_{22}^{+ +} {B B}_{11} {d d}_{i i}^{' '},, - - - - - - ((22)),,$

据此，发射机1根据待OFDM处理的数据信号序列生成相应的预留信号序列。Accordingly, the transmitter 1 generates a corresponding reserved signal sequence according to the data signal sequence to be processed by OFDM.

在步骤S2中，发射机1对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。例如，发射机1将数据信号序列和在步骤S1中根据该数据信号序列生成的预留信号序列整合在一起，并通过离散傅立叶逆变换模块(IDFT)将整合后的频域信号序列转化为相应的时域信号；然后在时域OFDM信号的前端加入循环前缀来对抗多径干扰，由脉冲成型滤波器产生数字基带信号，将该数字基带信号通过数模转换模块，转换为模拟信号，然后通过射频发射模块将信号移至合适的频带上，生成最终待传输的OFDM符号。In step S2, the transmitter 1 performs OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted. For example, transmitter 1 integrates the data signal sequence and the reserved signal sequence generated according to the data signal sequence in step S1, and converts the integrated frequency domain signal sequence into corresponding The time domain signal; then add a cyclic prefix to the front end of the time domain OFDM signal to combat multipath interference, generate a digital baseband signal by a pulse shaping filter, pass the digital baseband signal through a digital-to-analog conversion module, convert it into an analog signal, and then pass The radio frequency transmitting module moves the signal to a suitable frequency band to generate the final OFDM symbol to be transmitted.

优选地，在步骤S1中，发射机1还根据以下公式来生成所述预留信号序列：Preferably, in step S1, the transmitter 1 also generates the reserved signal sequence according to the following formula:

$= = {B B}_{22}^{+ +} {A A}_{22} {C C}_{i i - - 11}^{' '} + + {B B}_{22}^{+ +} {A A}_{11} {d d}_{i i - - 11}^{' '} - - {B B}_{22}^{+ +} {B B}_{11} {d d}_{i i}^{' '},,$

其中，C_i表示对于第i个OFDM符号的预留信号的频域值；A₁和B₁分别为以下矩阵A’的第一个K-nTR列的A′和B，A₂与B₂分别为以下矩阵A’最后nTR列的A’和B，Among them, C _i represents the frequency domain value of the reserved signal for the ith OFDM symbol; A ₁ and B ₁ are A' and B, A ₂ and B ₂ of the first K-nTR column of the following matrix A', respectively A' and B of the last nTR columns of the following matrix A', respectively,

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & 11 & 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & 11 \\ {k k}_{00} & {k k}_{11} & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - 11}^{' '} \\ \cdot \cdot & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; \\ \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot &Center Dot; \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot &Center Dot; \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - 11}^{' ' N N} \end{matrix})$

而B＝A′F′，例如，把载波索引集合κ分成两部分：κ₁＝{k₀，k₁.，k_K-nTR-1}与κ₂＝{k′_K-nTR，k′_K-nTR+1，...，k′_K-1}，其中，nTR表示用于预留和带外功率削减的子载波数量，k₀＜k₁＜...＜k_K-nTR-1，k′_K-nTR＜k′_K-nTR+1＜...＜k′_K-1；对于任何p₁∈κ₁，p₂∈κ₂，不能认为p₁＜p₂或者p₁＞p₂；假设并且And B=A'F', For example, divide the carrier index set κ into two parts: κ ₁ ={k ₀ , k ₁ ., k _K-nTR-1 } and κ ₂ ={k′ _K-nTR , k′ _K-nTR+1 , .. ., k′ _K-1 }, where nTR represents the number of subcarriers used for reservation and out-of-band power reduction, k ₀ <k ₁ <...<k _K-nTR-1 , k′ _K-nTR < k′ _K-nTR+1 ＜...＜k′ _K-1 ; for any p ₁ ∈κ ₁ , p ₂ ∈κ ₂ , it cannot be considered that p ₁ <p ₂ or p ₁ ＞p ₂ ; suppose and

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot \cdot \cdot &Center Dot; \cdot &Center Dot; & 11 & 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & 11 \\ {k k}_{00} & {k k}_{11} & \cdot &Center Dot; \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - 11}^{' '} \\ \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot \cdot \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; \\ \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - 11}^{' ' N N} \end{matrix}),,$

根据方程(2)，预留频率信号的值不仅取决于数据信号，同时还取决于数据子载波的位置和预留频率的位置。因此，对于预留频率，不同的预留信号位置可能导致不同的峰值功率和平均值功率。According to equation (2), the value of the reserved frequency signal not only depends on the data signal, but also depends on the position of the data subcarrier and the position of the reserved frequency. Therefore, for reserved frequencies, different reserved signal locations may result in different peak and average powers.

下述示例基于256子载波的OFDM系统，16QAM调制。对于初始的OFDM符号，设置C₀＝0。通过抽样周期为Tsamp＝Ts/2048＝Tg/144，其中Ts＝1/15ms的抽样信号来估计功率谱密度(PSD)，抽样后OFDM信号长度为2048，循环前缀长度是144。根据4096汉明窗口(4096-sampleHanningwindow)的平均周期图来获得功率谱密度(PSD)，抽样重叠长度是512。The following example is based on OFDM system with 256 subcarriers, 16QAM modulation. For the initial OFDM symbol, set C ₀ =0. The power spectral density (PSD) is estimated by sampling the signal whose sampling period is Tsamp=Ts/2048=Tg/144, where Ts=1/15ms. The length of the OFDM signal after sampling is 2048, and the length of the cyclic prefix is 144. The power spectral density (PSD) is obtained from the average periodogram of the 4096-sample Hanning window, and the sampling overlap length is 512.

出于比较的目的，图3示出传统的N阶连续性OFDM性能，其中，带内功率谱几乎是平的，同时带外功率可以降到-80dB。For comparison purpose, Fig. 3 shows the traditional N-order continuous OFDM performance, where the in-band power spectrum is almost flat, while the out-of-band power can drop to -80dB.

图4和图5分别示出基于RT的N阶连续OFDM技术的32个预留频率在等间距类型和随机类型时带外功率削减性能。本发明可以实现约27db的带外功率削减，因此N阶连续的OFDM信号的带外功率可以降到-72dB。同时，随着导数级数的逐渐增大(0-2)，传输带宽衰减的越来越快。此外，由于插入预留频率，带内功率的波动约为10db，而没有N阶连续性的信号带内功率波动约为5dB。Fig. 4 and Fig. 5 respectively show the out-of-band power reduction performance of 32 reserved frequencies of the RT-based N-order continuous OFDM technology in the equidistant type and random type. The present invention can realize about 27db of out-of-band power reduction, so the out-of-band power of N-order continuous OFDM signals can be reduced to -72dB. At the same time, as the derivative series gradually increases (0-2), the transmission bandwidth attenuates faster and faster. In addition, due to the insertion of the reserved frequency, the in-band power fluctuation is about 10dB, while the in-band power fluctuation of the signal without N-order continuity is about 5dB.

如图6和图7所示，当预留频率由32增加到64时，带外功率的削减有额外3dB的增益，然而带内功率的波动没有太大变化。As shown in Figure 6 and Figure 7, when the reserved frequency is increased from 32 to 64, the reduction of out-of-band power has an additional 3dB gain, but the fluctuation of in-band power does not change much.

分别测量数据子载波和预留频的平均功率，以确定基于RT的N阶连续OFDM技术在预留频率和带内波动的功率消耗，表1和表2示出基于20000个OFDM符号的统计结果示例。Measure the average power of data subcarriers and reserved frequencies separately to determine the power consumption of RT-based N-order continuous OFDM technology in reserved frequencies and in-band fluctuations. Table 1 and Table 2 show the statistical results based on 20,000 OFDM symbols example.

表1：基于RT的N阶连续OFDM技术的平均功率消耗(预留信号数量＝32)示例Table 1: Example of average power consumption (number of reserved signals = 32) of RT-based N-order continuous OFDM technique

表2：基于RT的N阶连续OFDM技术的平均功率消耗(预留信号数量＝32)示例Table 2: Example of average power consumption (number of reserved signals = 32) of RT-based N-order continuous OFDM technique

当预留频率的放置类型固定，而数量增加时，预留频率的功率随着导数阶数N的增加而线性增长。当有32个预留频率时，预留频率的平均功率可能超过数据信号的功率。但是当采用更多的预留频率，如64个，预留频率的平均功率至多就是数据信号平均功率的一半。此外，导数阶数N通常要比数据子载波K小很多。因此，当子载波数量很大时，预留频率的功率消耗是可以忽略的。When the placement type of the reserved frequencies is fixed and the number increases, the power of the reserved frequencies increases linearly with the increase of the derivative order N. When there are 32 reserved frequencies, the average power of the reserved frequencies may exceed the power of the data signal. But when more reserved frequencies are used, such as 64, the average power of the reserved frequencies is at most half of the average power of the data signal. Furthermore, the derivative order N is usually much smaller than the data subcarrier K. Therefore, when the number of subcarriers is large, the power consumption of reserved frequencies is negligible.

对于连续放置的类型，预留频率信号过于集中，导致在预留频率上的峰值功率均值来说大于数据信号的功率，但是其带外功率削减的性能几乎与等间距放置、随机放置相同，在此不再赘述。For the type of continuous placement, the reserved frequency signal is too concentrated, resulting in the average value of the peak power on the reserved frequency being greater than the power of the data signal, but the performance of its out-of-band power reduction is almost the same as that of equidistant placement and random placement. This will not be repeated here.

优选地，在步骤S2中，发射机1还对所述数据信号序列与所述预留信号序列进行子载波映射；对经过子载波映射的所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。如图8所示，在发射机端基于RT的N阶连续OFDM技术按以下步骤实现：Preferably, in step S2, the transmitter 1 further performs subcarrier mapping on the data signal sequence and the reserved signal sequence; performs OFDM on the subcarrier mapped data signal sequence and the reserved signal sequence processed to generate OFDM symbols to be transmitted. As shown in Figure 8, the RT-based N-order continuous OFDM technology at the transmitter is implemented in the following steps:

1)在第i个OFDM符号中，将K-nTR长度的频域信号d′_i送到映射模块来根据方程(2)计算长度为nTR的C′_i的值；1) In the i-th OFDM symbol, the frequency domain signal d' _i of K-nTR length is sent to the mapping module to calculate the value of C' _i whose length is nTR according to equation (2);

2)通过子载波映射模块，信号d′_i与C′_i整合到一起并且映射到它们各自对应的子载波上来产生完整的OFDM符号 2) Through the subcarrier mapping module, the signals d' _i and _C'i are integrated and mapped to their respective subcarriers to generate complete OFDM symbols

3)第i个OFDM符号的频域信号d_i通过离散傅立叶逆变换模块(IDFT)被转化为对应的时域信号；3) The frequency domain signal d _i of the ith OFDM symbol is converted into a corresponding time domain signal through an inverse discrete Fourier transform module (IDFT);

4)在时域OFDM信号的前端加入循环前缀来对抗多径干扰；4) Adding a cyclic prefix to the front end of the time-domain OFDM signal to combat multipath interference;

5)由脉冲成形滤波器模块产生最终发射的数字基带信号；5) Generate the final transmitted digital baseband signal by the pulse shaping filter module;

6)将步骤5)中产生的数字基带信号通过数模转转换模块，转换为模拟信号，然后通过射频发射模块将信号移至合适的频带上，生成最终待传输的OFDM符号。6) The digital baseband signal generated in step 5) is converted into an analog signal through a digital-to-analog conversion module, and then the signal is moved to a suitable frequency band through a radio frequency transmission module to generate the final OFDM symbol to be transmitted.

更优选地，所述子载波映射包括但不限于，以下任一种方式：More preferably, the subcarrier mapping includes, but is not limited to, any of the following methods:

1)将所述预留信号序列映射至连续放置的子载波；1) mapping the reserved signal sequence to consecutively placed subcarriers;

2)将所述预留信号序列映射至等距分布的子载波；2) mapping the reserved signal sequence to equidistantly distributed subcarriers;

3)将所述预留信号序列映射至随机分布的子载波。3) Mapping the reserved signal sequence to randomly distributed subcarriers.

其中，对于连续的类型，所有预留的频率必须放置在一起；对于等间距类型，预留频率等间距地分布于所有载波中；对于随机类型，预留频率是随机分布的，剩余的频率用于传送数据载波。如图9所示，斜线的子块表示数据传输子载波的位置，网格线的子块表示预留频率的位置。Among them, for the continuous type, all reserved frequencies must be placed together; for the equidistant type, the reserved frequencies are equally spaced among all carriers; for the random type, the reserved frequencies are randomly distributed, and the remaining frequencies are used for transmitting data carriers. As shown in FIG. 9 , sub-blocks with slashes represent positions of data transmission subcarriers, and sub-blocks with grid lines represent positions of reserved frequencies.

图10为根据本发明另一个方面的设备示意图，示出基于OFDM的通信系统的发射机中基于预留频率进行N阶连续OFDM处理的设备。其中，设备1包括生成装置11和处理装置12。具体地，生成装置11由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性；处理装置12对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。在此，所述通信系统包括有线通信系统或无线通信系统。Fig. 10 is a schematic diagram of equipment according to another aspect of the present invention, showing equipment for performing N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM-based communication system. Wherein, the device 1 includes generating means 11 and processing means 12 . Specifically, the generating device 11 generates a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal; the processing device 12 compares the data signal sequence and the reserved signal sequence OFDM processing is performed to generate OFDM symbols to be transmitted. Here, the communication system includes a wired communication system or a wireless communication system.

具体地，生成装置11由待OFDM处理的数据信号序列生成相应的预留信号序列，其用于保持传输信号的N阶连续性。更具体地，生成装置11通过如连续、等间距或者随机等方式放置数据载波信号和预留频率信号，并通过映射的方式使得待OFDM处理的数据信号序列生成相应的预留信号序列。例如，把载波索引集合κ分成两部分：κ₁＝{k₀，k₁，...，k_K-nTR-1}与κ₂＝{k′_K-nTR，k′_K-nTR+1，...，k′_K-1}，其中，nTR表示用于预留和带外功率削减的子载波数量，k₀＜k₁＜...＜k_K-nTR-1，k′_K-nTR＜k′_K-nTR+1＜...＜k′_K-1；对于任何p₁∈κ₁，p₂∈κ₂，不能认为p₁＜p₂或者p₁＞p₂；假设并且Specifically, the generating device 11 generates a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal. More specifically, the generating device 11 places the data carrier signal and the reserved frequency signal in a continuous, equidistant or random manner, and makes the data signal sequence to be processed by OFDM generate a corresponding reserved signal sequence by means of mapping. For example, the carrier index set κ is divided into two parts: κ ₁ ={k ₀ , k ₁ ,...,k _K-nTR-1 } and κ ₂ ={k′ _K-nTR , k′ _K-nTR+1 ,...,k′ _K-1 }, where nTR represents the number of subcarriers used for reservation and out-of-band power reduction, k ₀ <k ₁ <...<k _K-nTR-1 , k′ _{K -nTR} <k′ _K-nTR+1 <...<k′ _K-1 ; for any p ₁ ∈κ ₁ , p ₂ ∈κ ₂ , it cannot be considered that p ₁ <p ₂ or p ₁ >p ₂ ; assume and

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & 11 & 11 & 11 & \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot & 11 \\ {k k}_{00} & {k k}_{11} & \cdot \cdot \cdot \cdot \cdot \cdot & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - 11}^{' '} \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - 11}^{' ' N N} \end{matrix}),,$

据此，生成装置11根据待OFDM处理的数据信号序列生成相应的预留信号序列。Accordingly, the generating device 11 generates a corresponding reserved signal sequence according to the data signal sequence to be processed by OFDM.

处理装置12对所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。例如，处理装置12将数据信号序列和生成装置11根据该数据信号序列生成的预留信号序列整合在一起，并通过离散傅立叶逆变换模块(IDFT)将整合后的频域信号序列转化为相应的时域信号；然后在时域OFDM信号的前端加入循环前缀来对抗多径干扰，由脉冲成型滤波器产生数字基带信号，将该数字基带信号通过数模转换模块，转换为模拟信号，然后通过射频发射模块将信号移至合适的频带上，生成最终待传输的OFDM符号。The processing device 12 performs OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted. For example, the processing device 12 integrates the data signal sequence and the reserved signal sequence generated by the generating device 11 according to the data signal sequence, and converts the integrated frequency domain signal sequence into a corresponding Time-domain signal; then add a cyclic prefix to the front end of the time-domain OFDM signal to combat multipath interference, generate a digital baseband signal by a pulse shaping filter, pass the digital baseband signal through a digital-to-analog conversion module, convert it into an analog signal, and then pass it through a radio frequency The transmitting module moves the signal to a suitable frequency band to generate the final OFDM symbol to be transmitted.

优选地，生成装置11还根据以下公式来生成所述预留信号序列：Preferably, the generating device 11 also generates the reserved signal sequence according to the following formula:

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot &Center Dot; \cdot \cdot \cdot &Center Dot; & 11 & 11 & 11 & \cdot \cdot \cdot \cdot \cdot &Center Dot; & 11 \\ {k k}_{00} & {k k}_{11} & \cdot &Center Dot; \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot \cdot \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - 11}^{' '} \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; \\ \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot & \cdot &Center Dot; & \cdot &Center Dot; \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot \cdot \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - 11}^{' ' N N} \end{matrix})$

而B＝A′F′，例如，把载波索引集合κ分成两部分：κ₁＝{k₀，k₁，...，k_K-nTR-1}与κ₂＝{k′_K-nTR，k′_K-nTR+1，...，k′_K-1}，其中，nTR表示用于预留和带外功率削减的子载波数量，k₀＜k₁＜...＜k_K-nTR-1，k′_K-nTR＜k′_K-nTR+1＜...＜k′_K-1；对于任何p₁∈κ₁，p₂∈κ₂，不能认为p₁＜p₂或者p₁＞p₂；And B=A'F', For example, the carrier index set κ is divided into two parts: κ ₁ ={k ₀ , k ₁ ,...,k _K-nTR-1 } and κ ₂ ={k′ _K-nTR , k′ _K-nTR+1 ,...,k′ _K-1 }, where nTR represents the number of subcarriers used for reservation and out-of-band power reduction, k ₀ <k ₁ <...<k _K-nTR-1 , k′ _{K -nTR} <k′ _K-nTR+1 <...<k′ _K-1 ; for any p ₁ ∈ κ ₁ , p ₂ ∈ κ ₂ , p ₁ <p ₂ or p ₁ >p ₂ cannot be considered;

假设并且suppose and

${A A}^{' '} = = (\begin{matrix} 11 & 11 & \cdot \cdot \cdot \cdot \cdot &Center Dot; & 11 & 11 & 11 & \cdot \cdot \cdot &Center Dot; \cdot \cdot & 11 \\ {k k}_{00} & {k k}_{11} & \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11} & {k k}_{K K - - nTR nTR}^{' '} & {k k}_{K K - - nTR nTR + + 11}^{' '} & \cdot \cdot \cdot \cdot \cdot \cdot & {k k}_{K K - - 11}^{' '} \\ \cdot &Center Dot; & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot & \cdot &Center Dot; & \cdot \cdot \\ \cdot \cdot & \cdot \cdot & \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot &Center Dot; & \cdot \cdot & \cdot \cdot \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & \cdot \cdot \cdot \cdot \cdot &Center Dot; & {k k}_{K K - - nTR nTR - - 11}^{N N} & {k k}_{K K - - nTR nTR}^{' ' N N} & {k k}_{K K - - nTR nTR + + 11}^{' ' N N} & \cdot \cdot \cdot &Center Dot; \cdot \cdot & {k k}_{K K - - 11}^{' ' N N} \end{matrix}),,$

出于比较的目的，图4示出传统的N阶连续性OFDM性能，其中，带内功率谱几乎是平的，同时带外功率可以降到-80dB。For comparison purpose, Fig. 4 shows the traditional N-order continuous OFDM performance, where the in-band power spectrum is almost flat, while the out-of-band power can drop to -80dB.

图5和图6分别示出基于RT的N阶连续OFDM技术的32个预留频率在等间距类型和随机类型时带外功率削减性能。本发明可以实现约27db的带外功率削减，因此N阶连续的OFDM信号的带外功率可以降到-72dB。同时，随着导数级数的逐渐增大(0-2)，传输带宽衰减的越来越快。此外，由于插入预留频率，带内功率的波动约为10db，而没有N阶连续性的信号带内功率波动约为5dB。Figure 5 and Figure 6 respectively show the out-of-band power reduction performance of the 32 reserved frequencies of the RT-based N-order continuous OFDM technology in the equidistant type and random type. The present invention can realize about 27db of out-of-band power reduction, so the out-of-band power of N-order continuous OFDM signals can be reduced to -72dB. At the same time, as the derivative series gradually increases (0-2), the transmission bandwidth attenuates faster and faster. In addition, due to the insertion of the reserved frequency, the in-band power fluctuation is about 10dB, while the in-band power fluctuation of the signal without N-order continuity is about 5dB.

如图7和图8所示，当预留频率由32增加到64时，带外功率的削减有额外3dB的增益，然而带内功率的波动没有太大变化。As shown in Figure 7 and Figure 8, when the reserved frequency is increased from 32 to 64, the reduction of out-of-band power has an additional 3dB gain, but the fluctuation of in-band power does not change much.

分别测量数据子载波和预留频的平均功率，以确定基于RT的N阶连续OFDM技术在预留频率和带内波动的功率消耗，表3和表4示出基于20000个OFDM符号的统计结果示例。Measure the average power of the data subcarriers and reserved frequencies respectively to determine the power consumption of the RT-based N-order continuous OFDM technology fluctuating in the reserved frequencies and bands. Table 3 and Table 4 show the statistical results based on 20,000 OFDM symbols example.

表3：基于RT的N阶连续OFDM技术的平均功率消耗(预留信号数量＝32)示例Table 3: Example of average power consumption (number of reserved signals = 32) of RT-based N-order continuous OFDM technology

表4：基于RT的N阶连续OFDM技术的平均功率消耗(预留信号数量＝32)示例Table 4: Example of average power consumption (number of reserved signals = 32) of RT-based N-order continuous OFDM technique

优选地，处理装置12还包括子载波映射装置121和OFDM处理装置122，其中，子载波映射装置121对所述数据信号序列与所述预留信号序列进行子载波映射；OFDM处理装置122对经过子载波映射的所述数据信号序列与所述预留信号序列进行OFDM处理，以生成待传输的OFDM符号。如图8所示，在发射机端基于RT的N阶连续OFDM技术按以下步骤实现：Preferably, the processing device 12 further includes a subcarrier mapping device 121 and an OFDM processing device 122, wherein the subcarrier mapping device 121 performs subcarrier mapping on the data signal sequence and the reserved signal sequence; the OFDM processing device 122 performs subcarrier mapping on the The data signal sequence mapped to the subcarriers and the reserved signal sequence are subjected to OFDM processing to generate OFDM symbols to be transmitted. As shown in Figure 8, the RT-based N-order continuous OFDM technology at the transmitter is implemented in the following steps:

2)通过子载波映射模块，信号d′_i与C′_i整合到一起并且映射到它们各自对应的子载波上来产生完整的OFDM符号；2) Through the subcarrier mapping module, the signals d' _i and _C'i are integrated and mapped to their respective subcarriers to generate complete OFDM symbols ;

对于本领域技术人员而言，显然本发明不限于上述示范性实施例的细节，而且在不背离本发明的精神或基本特征的情况下，能够以其他的具体形式实现本发明。因此，无论从哪一点来看，均应将实施例看作是示范性的，而且是非限制性的，本发明的范围由所附权利要求而不是上述说明限定，因此旨在将落在权利要求的等同要件的含义和范围内的所有变化涵括在本发明内。不应将权利要求中的任何附图标记视为限制所涉及的权利要求。此外，显然“包括”一词不排除其他单元或步骤，单数不排除复数。系统权利要求中陈述的多个单元或装置也可以由一个单元或装置通过软件或者硬件来实现。第一，第二等词语用来表示名称，而并不表示任何特定的顺序。It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned. In addition, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or devices stated in the system claims may also be realized by one unit or device through software or hardware. The words first, second, etc. are used to denote names without implying any particular order.

Claims

1. A method for carrying out N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM communication system, wherein the method may further comprise the steps:

a corresponding reserved signal sequence is generated from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal, wherein the available subcarriers are divided into two parts, and one part is used for the data signal sequence, Another part is used for the reserved signal sequence;

b performing OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted;

Wherein, the OFDM processing includes:

- the data signal sequence and the reserved signal sequence are mapped to respective subcarriers to generate a complete OFDM signal;

- the OFDM signal is converted into a corresponding time-domain signal through an inverse discrete Fourier transform module;

-Add a cyclic prefix to the front end of the time-domain OFDM signal to combat multipath interference, generate a digital baseband signal through the pulse shaping filter module, and further convert it into a corresponding analog signal and move it to a suitable frequency band to generate OFDM symbols to be transmitted .

2. The method according to claim 1, wherein the step a further comprises: generating the reserved signal sequence according to the following formula:

\begin{matrix} {C C}_{i i}^{' '} = = {B B}_{22}^{+ +} (({A A}_{11} {d d}_{i i - - 11}^{' '} + + {A A}_{22} {C C}_{i i - - 11}^{' '} - - {B B}_{11} {d d}_{i i}^{' '})) \\ = = {B B}_{22}^{+ +} {A A}_{22} {C C}_{i i - - 11}^{' '} + + {B B}_{22}^{+ +} {A A}_{11} {d d}_{i i - - 11}^{' '} - - {B B}_{22}^{+ +} {B B}_{11} {d d}_{i i}^{' '} \end{matrix},,

Wherein, C' _i represents the frequency domain value of the reserved signal corresponding to the ith OFDM symbol d' _i in the data signal sequence;

The number of available subcarriers is K, which includes the subsets κ ₁ ={k ₀ ,k ₁ ,...,k _K-nTR-1 } and κ ₂ ={k′ _K-nTR ,k′ _{K-nTR+ 1} ,...,k' _K-1 }, the subset K ₁ is used to transmit the data signal sequence, and the subset K ₂ is used to transmit the reserved signal sequence;

A ₁ and B ₁ are respectively A' and B in the first K-nTR column of the following matrix A', A ₂ and B ₂ are respectively A' and B in the following nTR column of the following matrix A',

{A A}^{' '} = = (\begin{matrix} 11 & 11 & ... ... & 11 & 11 & 11 & ... ... & 11 \\ {k k}_{00} & {k k}_{11} & ... ... & {k k}_{K K - - n no T T R R - - 11} & {k k}_{K K - - n no T T R R}^{' '} & {k k}_{K K - - n no T T R R + + 11}^{' '} & ... ... & {k k}_{K K - - 11}^{' '} \\ \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & ... ... & {k k}_{K K - - n no T T R R - - 11}^{N N} & {k k}_{K K - - n no T T R R}^{' ' N N} & {k k}_{K K - - n no T T R R + + 11}^{' ' N N} & ... ... & {k k}_{K K - - 11}^{' ' N N} \end{matrix})

And B=A'F',

f^{'} = d i a g (e^{{jφk}_{0}}, e^{{jφk}_{1}}, ..., e^{{jφk}_{K - no T R - 1}}, e^{{jφk}_{K - no T R - 1}^{'}}, e^{{jφk}_{K - no T R + 1}^{'}}, ..., e^{{jφk}_{K - 1}^{'}})

T _g is the length of the cyclic prefix, and T _s is the length of the time-domain OFDM signal before adding the cyclic prefix.

3. The method according to claim 1, wherein the manner of performing subcarrier mapping on the reserved signal sequence comprises any of the following:

- mapping said reserved signal sequence to consecutively placed subcarriers;

- mapping the reserved signal sequence to equidistantly distributed subcarriers;

- mapping the reserved signal sequence to randomly distributed subcarriers.

4. The method according to any one of claims 1 to 3, wherein the communication system comprises a wired communication system or a wireless communication system.

5. A device for carrying out N-order continuous OFDM processing based on reserved frequencies in a transmitter of an OFDM communication system, wherein the device includes:

The generating device is used to generate a corresponding reserved signal sequence from the data signal sequence to be processed by OFDM, which is used to maintain the N-order continuity of the transmission signal, wherein the available subcarriers are divided into two parts, and one part is used for the A data signal sequence, another part is used for the reserved signal sequence;

A processing device, configured to perform OFDM processing on the data signal sequence and the reserved signal sequence to generate OFDM symbols to be transmitted;

Wherein, the OFDM processing includes:

6. The device according to claim 5, wherein the generating means is further configured to generate the reserved signal sequence according to the following formula:

\begin{matrix} {C C}_{i i}^{' '} = = {B B}_{22}^{+ +} (({A A}_{11} {d d}_{i i - - 11}^{' '} + + {A A}_{22} {C C}_{i i - - 11}^{' '} - - {B B}_{11} {d d}_{i i}^{' '})) \\ = = {B B}_{22}^{+ +} {A A}_{22} {C C}_{i i - - 11}^{' '} + + {B B}_{22}^{+ +} {A A}_{11} {d d}_{i i - - 11}^{' '} - - {B B}_{22}^{+ +} {B B}_{11} {d d}_{i i}^{' '} \end{matrix},,

{A A}^{' '} = = (\begin{matrix} 11 & 11 & ... ... & 11 & 11 & 11 & ... ... & 11 \\ {k k}_{00} & {k k}_{11} & ... ... & {k k}_{K K - - n no T T R R - - 11} & {k k}_{K K - - n no T T R R}^{' '} & {k k}_{K K - - n no T T R R + + 11}^{' '} & ... ... & {k k}_{K K - - 11}^{' '} \\ \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} & \begin{matrix} . . \\ . . \\ . . \end{matrix} \\ {k k}_{00}^{N N} & {k k}_{11}^{N N} & ... ... & {k k}_{K K - - n no T T R R - - 11}^{N N} & {k k}_{K K - - n no T T R R}^{' ' N N} & {k k}_{K K - - n no T T R R + + 11}^{' ' N N} & ... ... & {k k}_{K K - - 11}^{' ' N N} \end{matrix})

And B=A'F',

f^{'} = d i a g (e^{{jφk}_{0}}, e^{{jφk}_{1}}, ..., e^{{jφk}_{K - no T R - 1}}, e^{{jφk}_{K - no T R - 1}^{'}}, e^{{jφk}_{K - no T R + 1}^{'}}, ..., e^{{jφk}_{K - 1}^{'}})

7. The device according to claim 5, wherein the manner of performing subcarrier mapping on the reserved signal sequence comprises any of the following:

- mapping said reserved signal sequence to consecutively placed subcarriers;

- mapping the reserved signal sequence to randomly distributed subcarriers.

8. The apparatus according to any one of claims 5 to 7, wherein the communication system comprises a wired communication system or a wireless communication system.